EC-2073-2005微生物限量标准

EC-2073-2005微生物限量标准
EC-2073-2005微生物限量标准

2005R2073—EN—27.12.2007—001.001—1 This document is meant purely as a documentation tool and the institutions do not assume any liability for its contents

?B COMMISSION REGULATION(EC)No2073/2005

of15November2005

on microbiological criteria for foodstuffs

(Text with EEA relevance)

(OJ L338,22.12.2005,p.1)

Amended by:

Official Journal

No page date

?M1Commission Regulation(EC)No1441/2007of5December2007L322127.12.2007 Corrected by:

?C1Corrigendum,OJ L278,10.10.2006,p.32(2073/2005)

?C2Corrigendum,OJ L283,14.10.2006,p.62(2073/2005)

COMMISSION REGULATION (EC)No 2073/2005

of 15November 2005

on microbiological criteria for foodstuffs

(Text with EEA relevance)

THE COMMISSION OF THE EUROPEAN COMMUNITIES,Having regard to the Treaty establishing the European Community,Having regard to Regulation (EC)No 852/2004of the European Parliament and of the Council of 29April 2004on the hygiene of foodstuffs (1),and in particular Articles 4(4)and 12thereof,Whereas:

(1)

A high level of protection of public health is one of the funda-mental objectives of food law,as laid down in Regulation (EC)No 178/2002of the European Parliament and of the Council of 28January 2002laying down the general principles and requirements of food law,establishing the European Food Safety Authority and laying down procedures in matters of food safety (2).Microbiological hazards in foodstuffs form a major source of food-borne diseases in humans.

(2)

Foodstuffs should not contain micro-organisms or their toxins or metabolites in quantities that present an unacceptable risk for human health.

(3)

Regulation (EC)No 178/2002lays down general food safety requirements,according to which food must not be placed on the market if it is unsafe.Food business operators have an obli-gation to withdraw unsafe food from the market.In order to contribute to the protection of public health and to prevent differing interpretations,it is appropriate to establish harmonised safety criteria on the acceptability of food,in particular as regards the presence of certain pathogenic micro-organisms.

(4)

Microbiological criteria also give guidance on the acceptability of foodstuffs and their manufacturing,handling and distribution processes.The use of microbiological criteria should form an integral part of the implementation of HACCP-based procedures and other hygiene control measures.

(5)

The safety of foodstuffs is mainly ensured by a preventive approach,such as implementation of good hygiene practice and application of procedures based on hazard analysis and critical control point (HACCP)principles.Microbiological criteria can be used in validation and verification of HACCP procedures and other hygiene control measures.It is therefore appropriate to set microbiological criteria defining the acceptability of the processes,and also food safety microbiological criteria setting a limit above which a foodstuff should be considered unacceptably contaminated with the micro-organisms for which the criteria are set.

(6)

According to Article 4of Regulation (EC)No 852/2004,food business operators are to comply with microbiological criteria.This should include testing against the values set for the criteria through the taking of samples,the conduct of analyses and the implementation of corrective actions,in accordance with food law and the instructions given by the competent authority.It is therefore appropriate to lay down implementing measures

▼B

2005R2073—EN —27.12.2007—001.001—2

(1)OJ L 139,30.4.2004,p.1,corrected by OJ L 226,25.6.2004,p.3.

(2)OJ L 31,1.2.2002,p.1.Regulation as amended by Regulation (EC)No 1642/2003(OJ L 245,29.9.2003,p.4).

concerning the analytical methods,including,where necessary,the measurement uncertainty,the sampling plan,the microbio-logical limits,the number of analytical units that should comply with these limits.Furthermore,it is appropriate to lay down implementing measures concerning the foodstuff to which the criterion applies,the points of the food chain where the criterion applies,as well as the actions to be taken when the criterion is not met.The measures to be taken by the food business operators in order to ensure compliance with criteria defining the acceptability of a process may include,among other things,controls of raw materials,hygiene,temperature and shelf-life of the product.

(7)

Regulation (EC)No 882/2004of the European Parliament and of the Council of 29April 2004on official controls performed to ensure the verification of compliance with feed and food law,animal health and animal welfare rules (1)requires the Member States to ensure that official controls are carried out regularly,on a risk basis and with appropriate frequency.Those controls should take place at appropriate stages of the production,processing and distribution of food to ensure that the criteria laid down in this Regulation are complied with by food business operators.

(8)

The Communication from the Commission on the Community Strategy for setting microbiological criteria for foodstuffs (2)describes the strategy to lay down and revise the criteria in Community legislation,as well as the principles for the devel-opment and application of the criteria.This strategy should be applied when microbiological criteria are laid down.

(9)

The Scientific Committee on Veterinary Measures relating to Public Health (SCVPH)issued an opinion on 23September 1999on the evaluation of microbiological criteria for food products of animal origin for human consumption.It highlighted the relevance of basing microbiological criteria on formal risk assessment and internationally approved principles.The opinion recommends that microbiological criteria should be relevant and effective in relation to consumer health protection.The SCVPH proposed,while awaiting formal risk assessments,certain revised criteria as interim measures.

(10)

The SCVPH issued at the same time a separate opinion on Listeria monocytogenes .That opinion recommended that it be an objective to keep the concentration of Listeria monocytogenes in food below 100cfu/g.The Scientific Committee on Food (SCF)agreed with these recommendations in its opinion of 22June 2000.

(11)

The SCVPH adopted an opinion on Vibrio vulnificus and Vibrio-parahaemolyticus on 19and 20September 2001.It concluded that currently available scientific data do not support setting specific criteria for pathogenic V .vulnificus and parahaemo-lyticus in seafood.However,it recommended that codes of practice should be established to ensure that good hygiene practice has been applied.

(12)

The SCVPH issued an opinion on Norwalk-like viruses (NLVs,noroviruses)on 30-31January 2002.In that opinion it concluded that the conventional faecal indicators are unreliable for demon-strating the presence or absence of NLVs and that the reliance on faecal bacterial indicator removal for determining shellfish puri-fication times is unsafe practice.It also recommended using E.

▼B

2005R2073—EN —27.12.2007—001.001—3

(1)OJ L 165,30.4.2004,p.1,corrected by OJ L 191,28.5.2004,p.1.

(2)SANCO/1252/2001Discussion paper on strategy for setting microbiological criteria for foodstuffs in Community legislation,p.34.

coli rather than faecal coliforms to indicate faecal contamination in shellfish harvesting areas,when applying bacterial indicators.

(13)

On 27February 2002the SCF adopted an opinion on specifi-cations for gelatine in terms of consumer health.It concluded that the microbiological criteria set in Chapter 4of Annex II to Council Directive 92/118/EEC of 17December 1992laying down animal health and public health requirements governing trade in and imports into the Community of products not subject to the said requirements laid down in specific Community rules referred to in Annex A(I)to Directive 89/662/EEC and,as regards pathogens,to Directive 90/425/EEC (1)in terms of consumer health were excessive,and considered it sufficient to apply a mandatory microbiological criterion for salmonella only.

(14)

The SCVPH issued an opinion on verotoxigenic E.coli (VTEC)in foodstuffs on 21and 22January 2003.In its opinion it concluded that applying an end-product microbiological standard for VTEC O157is unlikely to deliver meaningful reductions in the associated risk for the consumers.However,microbiological guidelines aimed at reducing the faecal contam-ination along the food chain can contribute to a reduction in public health risks,including VTEC.The SCVPH identified the following food categories where VTEC represents a hazard to public health:raw or undercooked beef and possibly meat from other ruminants,minced meat and fermented beef and products thereof,raw milk and raw milk products,fresh produce,in particular sprouted seeds,and unpasteurised fruit and vegetable juices.

(15)

On 26and 27March 2003the SCVPH adopted an opinion on staphylococcal enterotoxins in milk products,particularly in cheeses.It recommended revising the criteria for coagulase-positive staphylococci in cheeses,in raw milk intended for processing and in powdered milk.In addition,criteria for staphy-lococcal enterotoxins should be laid down for cheeses and powdered milk.

(16)

The SCVPH adopted an opinion on salmonellae in foodstuffs on 14and 15April 2003.According to the opinion,food categories possibly posing a high risk to public health include raw meat and some products intended to be eaten raw,raw and undercooked products of poultry meat,eggs and products containing raw eggs,unpasteurised milk and some products thereof.Sprouted seeds and unpasteurised fruit juices are also of concern.It recom-mended that the decision on the need for microbiological criteria should be taken on the basis of its ability to protect the consumers and its feasibility.

(17)

The Scientific Panel on Biological Hazards (BIOHAZ Panel)of the European Food Safety Authority (EFSA)issued an opinion on the microbiological risks in infant formulae and follow-on formulae on 9September 2004.It concluded that Salmonella and Enterobacter sakazakii are the micro-organisms of greatest concern in infant formulae,formulae for special medical purposes and follow-on formulae.The presence of these pathogens constitutes a considerable risk if conditions after reconstitution permit multiplication.Enterobacteriaceae ,which are more often present,could be used as an indicator for risk.Monitoring and testing of Enterobacteriaceae was recommended in both the manufacturing environment and the finished product by the EFSA.However,besides pathogenic species the family Entero-bacteriaceae includes also environmental species,which often appear in the food manufacturing environment without posing

▼B

2005R2073—EN —27.12.2007—001.001—4

(1)OJ L 62,15.3.1993,p.49.Directive as last amended by Commission Regu-lation (EC)No 445/2004(OJ L 72,11.3.2004,p.60).

any health hazard.Therefore,the family Enterobacteriaceae can be used for routine monitoring,and if they are present testing of specific pathogens can be started.

(18)

International guidelines for microbiological criteria in respect of many foodstuffs have not yet been established.However,the Commission has followed the Codex Alimentarius guideline ‘Principles for the establishment and application of microbio-logical criteria for foods CAC/GL 21—1997’and in addition,the advice of the SCVPH and the SCF in laying down micro-biological criteria.Existing Codex specifications in respect of dried milk products,foods for infants and children and the histamine criterion for certain fish and fishery products have been taken account.The adoption of Community criteria should benefit trade by providing harmonised microbiological requirements for foodstuffs and replacing national criteria.(19)

The microbiological criteria set for certain categories of food of animal origin in Directives that were repealed by Directive 2004/41/EC of the European Parliament and of the Council of 21April 2004repealing certain Directives concerning food hygiene and health conditions for the production and placing on the market of certain products of animal origin intended for human consumption and amending Council Directives 89/662/EEC and 92/118/EEC and Council Decision 95/408/EC (1)should be revised and certain new criteria set in the light of the scientific advice.

(20)

The microbiological criteria laid down in Commission Decision 93/51EEC of 15December 1992on the microbiological criteria applicable to the production of cooked crustaceans and molluscan shellfish (2)are incorporated in this Regulation.It is therefore appropriate to repeal that Decision.Since Commission Decision 2001/471/EC of 8June 2001laying down rules for the regular checks on the general hygiene carried out by the operators in establishments according to Directive 64/433/EEC on health conditions for the production and marketing of fresh meat and Directive 71/118/EEC on health problems affecting the production and placing on the market of fresh poultrymeat (3)is repealed with effect from the 1January 2006,it is appropriate to incorporate microbiological criteria set for carcases in this Regu-lation.

(21)

The producer or manufacturer of a food product has to decide whether the product is ready to be consumed as such,without the need to cook or otherwise process it in order to ensure its safety and compliance with the microbiological criteria.According to Article 3of Directive 2000/13/EC of the European Parliament and of the Council of 20March 2000on the approximation of the laws of the Member States relating to the labelling,presen-tation and advertising of foodstuffs (4),the instructions for use of a foodstuff are compulsory on the labelling when it would be impossible to make appropriate use of the foodstuff in the absence of such instructions.Such instructions should be taken into account by food business operators when deciding appro-priate sampling frequencies for the testing against microbiological criteria.

(22)

Sampling of the production and processing environment can be a useful tool to identify and prevent the presence of pathogenic micro-organisms in foodstuffs.

▼B

2005R2073—EN —27.12.2007—001.001—5

(1)OJ L 157,30.4.2004,p.33,corrected by OJ L 195,2.6.2004,p.12.(2)OJ L 13,21.1.1993,p.11.

(3)OJ L 165,21.6.2001,p.48.Decision as amended by Decision 2004/379/EC (OJ L 144,30.4.2004,p.1).(4)OJ L 109,6.5.2000,p.29.Directive as last amended by Directive 2003/89/EC (OJ L 308,25.11.2003,p.15).

(23)

Food business operators should decide themselves the necessary sampling and testing frequencies as part of their procedures based on HACCP principles and other hygiene control procedures.However,it may be necessary in certain cases to set harmonised sampling frequencies at Community level,particularly in order to ensure the same level of controls to be performed throughout the Community.

(24)

Test results are dependent on the analytical method used,and therefore a given reference method should be associated with each microbiological criterion.However,food business operators should have the possibility to use analytical methods other than the reference methods,in particular more rapid methods,as long as the use of these alternative methods provides equivalent results.Moreover,a sampling plan needs to be defined for each criterion in order to ensure harmonised imple-mentation.It is nevertheless necessary to allow the use of other sampling and testing schemes,including the use of alternative indicator organisms,on condition that these schemes provide equivalent guarantees of food safety.

(25)

Trends in test results should be analysed,as they are able to reveal unwanted developments in the manufacturing process enabling the food business operator to take corrective actions before the process is out of control.

(26)

The microbiological criteria set in this Regulation should be open to review and revised or supplemented,if appropriate,in order to take into account developments in the field of food safety and food microbiology.This includes progress in science,technology and methodology,changes in prevalence and contamination levels,changes in the population of vulnerable consumers,as well as the possible outputs from risk assessments.

(27)

In particular,criteria for pathogenic viruses in live bivalve molluscs should be established when the analytical methods are developed sufficiently.There is a need for development of reliable methods for other microbial hazards too, e.g.Vibrio parahaemolyticus.

(28)

It has been demonstrated that the implementation of control programmes can markedly contribute to a reduction of the prevalence of salmonella in production animals and products thereof.The purpose of Regulation (EC)No 2160/2003of the European Parliament and of the Council of 17November 2003on the control of salmonella and other specified food-borne zoonotic agents (1)is to ensure that proper and effective measures are taken to control salmonella at relevant stages of the food chain.Criteria for meat and products thereof should take into account the expected improvement in the salmonella situation at the level of primary production.

(29)

For certain food safety criteria,it is appropriate to grant the Member States a transitional derogation,enabling them to comply with less stringent criteria but provided that the foodstuffs would only be marketed on the national market.The Member States should notify the Commission and other Member States where this transitional derogation is used.

(30)

The measures provided for in this Regulation are in accordance with the opinion of the Standing Committee on the Food Chain and Animal Health,

▼B

2005R2073—EN —27.12.2007—001.001—6

(1)OJ L 325,12.12.2003,p.1.

HAS ADOPTED THIS REGULATION:

Article 1

Subject-matter and scope

This Regulation lays down the microbiological criteria for certain micro-organisms and the implementing rules to be complied with by food business operators when implementing the general and specific hygiene measures referred to in Article 4of Regulation (EC)No 852/2004.The competent authority shall verify compliance with the rules and criteria laid down in this Regulation in accordance with Regulation (EC)No 882/2004,without prejudice to its right to undertake further sampling and analyses for the purpose of detecting and measuring other micro-organisms,their toxins or metabolites,either as a verification of processes,for food suspected of being unsafe,or in the context of a risk analysis.

This Regulation shall apply without prejudice to other specific rules for the control of micro-organisms laid down in Community legislation and in particular the health standards for foodstuffs laid down in Regulation (EC)No 853/2004of the European Parliament and of the Council (1),the rules on parasites laid down under Regulation (EC)No 854/2004of the European Parliament and of the Council (2)and the microbiological criteria laid down under Council Directive 80/777/EEC (3).

Article 2Definitions

The following definitions shall apply:

(a)‘micro-organisms ’means bacteria,viruses,yeasts,moulds,algae,

parasitic protozoa,microscopic parasitic helminths,and their toxins and metabolites;(b)‘microbiological criterion ’means a criterion defining the accept-ability of a product,a batch of foodstuffs or a process,based on the absence,presence or number of micro-organisms,and/or on the quantity of their toxins/metabolites,per unit(s)of mass,volume,area or batch;(c)‘food safety criterion ’means a criterion defining the acceptability of

a product or a batch of foodstuff applicable to products placed on the market;(d)‘process hygiene criterion ’a criterion indicating the acceptable func-tioning of the production process.Such a criterion is not applicable to products placed on the market.It sets an indicative contamination value above which corrective actions are required in order to maintain the hygiene of the process in compliance with food law;(e)‘batch ’means a group or set of identifiable products obtained from

a given process under practically identical circumstances and produced in a given place within one defined production period;(f)‘shelf-life ’means either the period corresponding to the period

preceding the ‘use by ’or the minimum durability date,as defined respectively in Articles 9and 10of Directive 2000/13/EC;(g)‘ready-to-eat food ’means food intended by the producer or the

manufacturer for direct human consumption without the need for cooking or other processing effective to eliminate or reduce to an acceptable level micro-organisms of concern;

▼B

2005R2073—EN —27.12.2007—001.001—7

(1)OJ L 139,30.4.2004,p.55,corrected by OJ L 226,25.6.2004,p.22.(2)OJ L 139,30.4.2004,p.206,corrected by OJ L 226,25.6.2004,p.83.(3)OJ L 229,30.8.1980,p.1.

(h)‘food intended for infants ’means food specifically intended for

infants,as defined in Commission Directive 91/321/EEC (1);(i)‘food intended for special medical purposes ’means dietary food for

special medical purposes,as defined in Commission Directive 1999/21/EC (2);(j)‘sample ’means a set composed of one or several units or a portion

of matter selected by different means in a population or in an important quantity of matter,which is intended to provide infor-mation on a given characteristic of the studied population or matter and to provide a basis for a decision concerning the population or matter in question or concerning the process which has produced it;(k)‘representative sample ’means a sample in which the characteristics

of the batch from which it is drawn are maintained.This is in particular the case of a simple random sample where each of the items or increments of the batch has been given the same prob-ability of entering the sample;(l)‘compliance with microbiological criteria ’means obtaining satis-factory or acceptable results set in Annex I when testing against the values set for the criteria through the taking of samples,the conduct of analyses and the implementation of corrective action,in accordance with food law and the instructions given by the competent authority.

Article 3General requirements

1.Food business operators shall ensure that foodstuffs comply with the relevant microbiological criteria set out in Annex I.To this end the food business operators at each stage of food production,processing and distribution,including retail,shall take measures,as part of their procedures based on HACCP principles together with the implemen-tation of good hygiene practice,to ensure the following:

(a)that the supply,handling and processing of raw materials and food-stuffs under their control are carried out in such a way that the process hygiene criteria are met,(b)that the food safety criteria applicable throughout the shelf-life of

the products can be met under reasonably foreseeable conditions of distribution,storage and use.2.As necessary,the food business operators responsible for the manufacture of the product shall conduct studies in accordance with Annex II in order to investigate compliance with the criteria throughout the shelf-life.In particular,this applies to ready-to-eat foods that are able to support the growth of Listeria monocytogenes and that may pose a Listeria monocytogenes risk for public health.

Food businesses may collaborate in conducting those studies.Guidelines for conducting those studies may be included in the guides to good practice referred to in Article 7of Regulation (EC)No 852/2004.

Article 4

Testing against criteria

1.Food business operators shall perform testing as appropriate against the microbiological criteria set out in Annex I,when they are

▼B

2005R2073—EN —27.12.2007—001.001—8

(1)OJ L 175,4.7.1991,p.35.(2)OJ L 91,7.4.1999,p.29.

2005R2073—EN—27.12.2007—001.001—9

▼B

validating or verifying the correct functioning of their procedures based

on HACCP principles and good hygiene practice.

2.Food business operators shall decide the appropriate sampling

frequencies,except where Annex I provides for specific sampling

frequencies,in which case the sampling frequency shall be at least

that provided for in Annex I.Food business operators shall make this

decision in the context of their procedures based on HACCP principles

and good hygiene practice,taking into account the instructions for use

of the foodstuff.

The frequency of sampling may be adapted to the nature and size of the

food businesses,provided that the safety of foodstuffs will not be

endangered.

Article5

Specific rules for testing and sampling

1.The analytical methods and the sampling plans and methods in

Annex I shall be applied as reference methods.

2.Samples shall be taken from processing areas and equipment used

in food production,when such sampling is necessary for ensuring that

the criteria are met.In that sampling the ISO standard18593shall be

used as a reference method.

Food business operators manufacturing ready-to-eat foods,which may

pose a Listeria monocytogenes risk for public health,shall sample the

processing areas and equipment for Listeria monocytogenes as part of

their sampling scheme.

Food business operators manufacturing dried infant formulae or dried

foods for special medical purposes intended for infants below six

months which pose an Enterobacter sakazakii risk shall monitor the

processing areas and equipment for Enterobacteriaceae as part of

their sampling scheme.

3.The number of sample units of the sampling plans set out in

Annex I may be reduced if the food business operator can demonstrate

by historical documentation that he has effective HACCP-based

procedures.

4.If the aim of the testing is to specifically assess the acceptability of

a certain batch of foodstuffs or a process,the sampling plans set out in

Annex I shall be respected as a minimum.

5.Food business operators may use other sampling and testing

procedures,if they can demonstrate to the satisfaction of the

competent authority that these procedures provide at least equivalent

guarantees.Those procedures may include use of alternative sampling

sites and use of trend analyses.

Testing against alternative micro-organisms and related microbiological

limits as well as testing of analytes other than microbiological ones shall

be allowed only for process hygiene criteria.

The use of alternative analytical methods is acceptable when the

methods are validated against the reference method in Annex I and if

a proprietary method,certified by a third party in accordance with the

protocol set out in EN/ISO standard16140or other internationally

accepted similar protocols,is used.

If the food business operator wishes to use analytical methods other

than those validated and certified as described in paragraph3the

methods shall be validated according to internationally accepted

protocols and their use authorised by the competent authority.

2005R2073—EN—27.12.2007—001.001—10

▼B

Article6

Labelling requirements

1.When the requirements for Salmonella in minced meat,meat

preparations and meat products intended to be eaten cooked of all

species set down in Annex I are fulfilled,the batches of those

products placed on the market must be clearly labelled by the manu-

facturer in order to inform the consumer of the need for thorough

cooking prior to consumption.

2.As from1January2010labelling as referred to in paragraph1in

respect of minced meat,meat preparations and meat products made

from poultrymeat will no longer be required.

Article7

Unsatisfactory results

1.When the results of testing against the criteria set out in Annex I

are unsatisfactory,the food business operators shall take the measures

laid down in paragraphs2to4of this Article together with other

corrective actions defined in their HACCP-based procedures and other

actions necessary to protect the health of consumers.

In addition,they shall take measures to find the cause of the unsatis-

factory results in order to prevent the recurrence of the unacceptable

microbiological contamination.Those measures may include modifi-

cations to the HACCP-based procedures or other food hygiene control

measures in place.

2.When testing against food safety criteria set out in Chapter1of

Annex I provides unsatisfactory results,the product or batch of food-

stuffs shall be withdrawn or recalled in accordance with Article19of

Regulation(EC)No178/2002.However,products placed on the market,

which are not yet at retail level and which do not fulfil the food safety

criteria,may be submitted to further processing by a treatment elimi-

nating the hazard in question.This treatment may only be carried out by

food business operators other than those at retail level.

The food business operator may use the batch for purposes other than

those for which it was originally intended,provided that this use does

not pose a risk for public or animal health and provided that this use has

been decided within the procedures based on HACCP principles and

good hygiene practice and authorised by the competent authority.

3.A batch of mechanically separated meat(MSM)produced with the

techniques referred to in Chapter III,paragraph3,in Section V of

Annex III to Regulation(EC)No853/2004,with unsatisfactory

results in respect of the Salmonella criterion,may be used in the food

chain only to manufacture heat-treated meat products in establishments

approved in accordance with Regulation(EC)No853/2004.

4.In the event of unsatisfactory results as regards process hygiene

criteria the actions laid down in Annex I,Chapter2shall be taken.

Article8

Transitional derogation

1.A transitional derogation is granted until31December2009at the

latest pursuant to Article12of Regulation(EC)No852/2004as regards

compliance with the value set in Annex I to this Regulation for

Salmonella in minced meat,meat preparations and meat products

intended to be eaten cooked placed on the national market of a

Member State.

2005R2073—EN—27.12.2007—001.001—11

▼B

2.The Member States using this possibility shall notify the

Commission and other Member States thereof.The Member State shall:

(a)guarantee that the appropriate means,including labelling and a

special mark,which cannot be confused with the identification

mark provided for in Annex II,Section I to Regulation(EC)No

853/2004,are in place to ensure that the derogation applies only to

the products concerned when placed on the domestic market,and

that products dispatched for intra-Community trade comply with the

criteria laid down in Annex I;

(b)provide that the products to which such transitional derogation

applies shall be clearly labelled that they must be thoroughly

cooked prior to consumption;

(c)undertake that when testing against the Salmonella criterion

pursuant to Article4,and for the result to be acceptable as

regards such transitional derogation,no more than one out of five

sample units shall be found to be positive.

Article9

Analyses of trends

Food business operators shall analyse trends in the test results.When

they observe a trend towards unsatisfactory results,they shall take

appropriate actions without undue delay to remedy the situation in

order to prevent the occurrence of microbiological risks.

Article10

Review

This Regulation shall be reviewed taking into account progress in

science,technology and methodology,emerging pathogenic micro-

organisms in foodstuffs,and information from risk assessments.In

particular,the criteria and conditions concerning the presence of

salmonella in carcases of cattle,sheep,goats,horses,pigs and poultry

shall be revised in the light of the changes observed in salmonella

prevalence.

Article11

Repeal

Decision93/51/EEC is repealed.

Article12

This Regulation shall enter into force on the20th day following its

publication in the Official Journal of the European Union.

It shall apply from1January2006.

This Regulation shall be binding in its entirety and directly applicable in

all Member States.

2005R2073—EN—27.12.2007—001.001—12

▼M1

ANNEX I

Microbiological criteria for foodstuffs

Chapter1.Food safety criteria............................................

Chapter2.Process hygiene criteria.........................................

2.1Meat and products thereof.......................................

2.2Milk and dairy products.........................................

2.3Egg products................................................

2.4Fishery products..............................................

2.5Vegetables,fruits and products thereof...............................

Chapter3.Rules for sampling and preparation of test samples......................

3.1General rules for sampling and preparation of test samples.................

3.2Bacteriological sampling in slaughterhouses and at premises producing minced meat

and meat preparations..........................................

2005R2073—EN —27.12.2007—001.001—

13

C h a p t e r 1.F o o d s a f e t y c r i t e r i a

M 1

2005R2073—EN—27.12.2007—001.001—

14

1

M

2005R2073—EN—27.12.2007—001.001—

15

1

M

2005R2073—EN —27.12.2007—001.001—

16

(1)n =n u m b e r o f u n i t s c o m p r i s i n g t h e s a m p l e ;c =n u m b e r o f s a m p l e u n i t s g i v i n g v a l u e s b e t w e e n m a n d M .(2)F o r p o i n t s 1.1-1.25m =M .(3)T h e m o s t r e c e n t e d i t i o n o f t h e s t a n d a r d s h a l l b e u s e d .(4)

R e g u l a r t e s t i n g a g a i n s t t h e c r i t e r i o n i s n o t r e q u i r e d i n n o r m a l c i r c u m s t a n c e s f o r t h e f o l l o w i n g r e a d y -t o -e a t f o o d s :—t h o s e w h i c h h a v e r e c e i v e d h e a t t r e a t m e n t o r o t h e r p r o c e s s i n g e f f e c t i v e t o e l i m i n a t e L .m o n o c y t o g e n e s ,w h e n r e c o n t a m i n a t i o n i s n o t p o s s i b l e a f t e r t h i s t r e a t m e n t (f o r e x a m p l e ,p r o d u c t s h e a t t r e a t e d i n t h e i r f i n a l p a c k a g e ),—f r e s h ,u n c u t a n d u n p r o c e s s e d v e g e t a b l e s a n d f r u i t s ,e x c l u d i n g s p r o u t e d s e e d s ,—b r e a d ,b i s c u i t s a n d s i m i l a r p r o d u c t s ,—b o t t l e d o r p a c k e d w a t e r s ,s o f t d r i n k s ,b e e r ,c i d e r ,w i n e ,s p i r i t s a n d s i m i l a r p r o d u c t s ,—s u g a r ,h o n e y a n d c o n f e c t i o n e r y ,i n c l u d i n g c o c o a a n d c h o c o l a t e p r o d u c t s ,—l i v e b i v a l v e m o l l u s c s .(5)T h i s c r i t e r i o n s h a l l a p p l y i f t h e m a n u f a c t u r e r i s a b l e t o d e m o n s t r a t e ,t o t h e s a t i s f a c t i o n o f t h e c o m p e t e n t a u t h o r i t y ,t h a t t h e p r o d u c t w i l l n o t e x c e e d t h e l i m i t 100c f u /g t h r o u g h o u t t h e s h e l f -l i f e .T h e o p e r a t o r m a y f i x i n t e r m e d i a t e l i m i t s d u r i n g t h e p r o c e s s t h a t m u s t b e l o w e n o u g h t o g u a r a n t e e t h a t t h e l i m i t o f 100c f u /g i s n o t e x c e e d e d a t t h e e n d o f s h e l f -l i f e .(6)1m l o f i n o c u l u m i s p l a t e d o n a P e t r i d i s h o f 140m m d i a m e t e r o r o n t h r e e P e t r i d i s h e s o f 90m m d i a m e t e r .(7)T h i s c r i t e r i o n s h a l l a p p l y t o p r o d u c t s b e f o r e t h e y h a v e l e f t t h e i m m e d i a t e c o n t r o l o f t h e p r o d u c i n g f o o d b u s i n e s s o p e r a t o r ,w h e n h e i s n o t a b l e t o d e m o n s t r a t e ,t o t h e s a t i s f a c t i o n o f t h e c o m p e t e n t a u t h o r i t y ,t h a t t h e p r o d u c t w i l l n o t e x c e e d t h e l i m i t o f 100c f u /g t h r o u g h o u t t h e s h e l f -l i f e .(8)P r o d u c t s w i t h p H ≤4,4o r a w ≤0,92,p r o d u c t s w i t h p H ≤5,0a n d a w ≤0,94,p r o d u c t s w i t h a s h e l f -l i f e o f l e s s t h a n f i v e d a y s s h a l l b e a u t o m a t i c a l l y c o n s i d e r e d t o b e l o n g t o t h i s c a t e g o r y .O t h e r c a t e g o r i e s o f p r o d u c t s c a n a l s o b e l o n g t o t h i s c a t e g o r y ,s u b j e c t t o s c i e n t i f i c j u s t i f i c a t i o n .(9)T h i s c r i t e r i o n s h a l l a p p l y t o m e c h a n i c a l l y s e p a r a t e d m e a t (M S M )p r o d u c e d w i t h t h e t e c h n i q u e s r e f e r r e d t o i n p a r a g r a p h 3o f C h a p t e r I I I o f S e c t i o n V o f A n n e x I I I t o R e g u l a t i o n (E C )N o 853/2004o f t h e E u r o p e a n P a r l i a m e n t a n d o f t h e C o u n c i l .(10)E x c l u d i n g p r o d u c t s w h e n t h e m a n u f a c t u r e r c a n d e m o n s t r a t e t o t h e s a t i s f a c t i o n o f t h e c o m p e t e n t a u t h o r i t i e s t h a t ,d u e t o t h e r i p e n i n g t i m e a n d a w o f t h e p r o d u c t w h e r e a p p r o p r i a t e ,t h e r e i s n o s a l m o n e l l a r i s k .(11)O n l y i c e c r e a m s c o n t a i n i n g m i l k i n g r e d i e n t s .(12)P r e l i m i n a r y t e s t i n g o f t h e b a t c h o f s e e d s b e f o r e s t a r t i n g t h e s p r o u t i n g p r o c e s s o r t h e s a m p l i n g m u s t b e c a r r i e d o u t a t t h e s t a g e w h e r e t h e h i g h e s t p r o b a b i l i t y o f f i n d i n g S a l m o n e l l a i s e x p e c t e d .(13)R e f e r e n c e :C o m m u n i t y r e f e r e n c e l a b o r a t o r y f o r c o a g u l a s e p o s i t i v e s t a p h y l o c o c c i .E u r o p e a n s c r e e n i n g m e t h o d f o r t h e d e t e c t i o n o f s t a p h y l o c o c c a l e n t e r o t o x i n s i n m i l k a n d m i l k p r o d u c t s .(14)P a r a l l e l t e s t i n g f o r E n t e r o b a c t e r i a c e a e a n d E .s a k a z a k i i s h a l l b e c o n d u c t e d ,u n l e s s a c o r r e l a t i o n b e t w e e n t h e s e m i c r o -o r g a n i s m s h a s b e e n e s t a b l i s h e d a t a n i n d i v i d u a l p l a n t l e v e l .I f E n t e r o b a c t e r i a c e a e a r e d e t e c t e d i n a n y o f t h e p r o d u c t s a m p l e s t e s t e d i n s u c h a p l a n t ,t h e b a t c h m u s t b e t e s t e d f o r E .s a k a z a k i i .I t s h a l l b e t h e r e s p o n s i b i l i t y o f t h e m a n u f a c t u r e r t o d e m o n s t r a t e t o t h e s a t i s f a c t i o n o f t h e c o m p e t e n t a u t h o r i t y w h e t h e r s u c h a c o r r e l a t i o n e x i s t s b e t w e e n E n t e r o b a c t e r i a c e a e a n d E .s a k a z a k i i .(15)E .c o l i i s u s e d h e r e a s a n i n d i c a t o r o f f a e c a l c o n t a m i n a t i o n .(16)A p o o l e d s a m p l e c o m p r i s i n g a m i n i m u m o f 10i n d i v i d u a l a n i m a l s .(17)P a r t i c u l a r l y f i s h s p e c i e s o f t h e f a m i l i e s :S c o m b r i d a e ,C l u p e i d a e ,E n g r a u l i d a e ,C o r y f e n i d a e ,P o m a t o m i d a e ,S c o m b r e s o s i d a e .(18)S i n g l e s a m p l e s m a y b e t a k e n a t r e t a i l l e v e l .I n s u c h a c a s e t h e p r e s u m p t i o n l a i d d o w n i n A r t i c l e 14(6)o f R e g u l a t i o n (E C )N o 178/2002,a c c o r d i n g t o w h i c h t h e w h o l e b a t c h i s t o b e d e e m e d u n s a f e ,s h a l l n o t a p p l y .(19)R e f e r e n c e s :1.M a l l e P .,V a l l e M .,B o u q u e l e t S .A s s a y o f b i o g e n i c a m i n e s i n v o l v e d i n f i s h d e c o m p o s i t i o n .J .A O A C I n t e r n a t .1996,79,43-49.2.D u f l o s G .,D e r v i n C .,M a l l e P .,B o u q u e l e t S .R e l e v a n c e o f m a t r i x e f f e c t i n d e t e r m i n a t i o n o f b i o g e n i c a m i n e s i n p l a i c e (P l e u r o n e c t e s p l a t e s s a )a n d w h i t i n g (M e r l a n g u s m e r l a n g u s .J .A O A C I n t e r n a t .1999,82,1097-1101.

M 1

2005R2073—EN —27.12.2007—001.001—17

I n t e r p r e t a t i o n o f t h e t e s t r e s u l t s

T h e l i m i t s g i v e n r e f e r t o e a c h s a m p l e u n i t t e s t e d ,e x c l u d i n g l i v e b i v a l v e m o l l u s c s a n d l i v e e c h i n o d e r m s ,t u n i c a t e s a n d g a s t r o p o d s i n r e l a t i o n t o t e s t i n g E .c o l i ,w h e r e t h e l i m i t r e f e r s t o a p o o l e d s a m p l e .

T h e t e s t r e s u l t s d e m o n s t r a t e t h e m i c r o b i o l o g i c a l q u a l i t y o f t h e b a t c h t e s t e d (1).

L .m o n o c y t o g e n e s i n r e a d y -t o -e a t f o o d s i n t e n d e d f o r i n f a n t s a n d f o r s p e c i a l m e d i c a l p u r p o s e s :

—s a t i s f a c t o r y ,i f a l l t h e v a l u e s o b s e r v e d i n d i c a t e t h e a b s e n c e o f t h e b a c t e r i u m ,

—u n s a t i s f a c t o r y ,i f t h e p r e s e n c e o f t h e b a c t e r i u m i s d e t e c t e d i n a n y o f t h e s a m p l e u n i t s .

L .m o n o c y t o g e n e s i n r e a d y -t o -e a t f o o d s a b l e t o s u p p o r t t h e g r o w t h o f L .m o n o c y t o g e n e s b e f o r e t h e f o o d h a s l e f t t h e i m m e d i a t e c o n t r o l o f t h e p r o d u c i n g f o o d b u s i n e s s o p e r a t o r w h e n h e i s n o t a b l e t o d e m o n s t r a t e t h a t t h e p r o d u c t w i l l n o t e x c e e d t h e l i m i t o f 100c f u /g t h r o u g h o u t t h e s h e l f -l i f e :

—s a t i s f a c t o r y ,i f a l l t h e v a l u e s o b s e r v e d i n d i c a t e t h e a b s e n c e o f t h e b a c t e r i u m ,

—u n s a t i s f a c t o r y ,i f t h e p r e s e n c e o f t h e b a c t e r i u m i s d e t e c t e d i n a n y o f t h e s a m p l e u n i t s .

L .m o n o c y t o g e n e s i n o t h e r r e a d y -t o -e a t f o o d s a n d E .c o l i i n l i v e b i v a l v e m o l l u s c s :

—s a t i s f a c t o r y ,i f a l l t h e v a l u e s o b s e r v e d a r e ≤t h e l i m i t ,

—u n s a t i s f a c t o r y ,i f a n y o f t h e v a l u e s a r e >t h e l i m i t .

S a l m o n e l l a i n d i f f e r e n t f o o d c a t e g o r i e s :

—s a t i s f a c t o r y ,i f a l l t h e v a l u e s o b s e r v e d i n d i c a t e t h e a b s e n c e o f t h e b a c t e r i u m ,

—u n s a t i s f a c t o r y ,i f t h e p r e s e n c e o f t h e b a c t e r i u m i s d e t e c t e d i n a n y o f t h e s a m p l e u n i t s .

S t a p h y l o c o c c a l e n t e r o t o x i n s i n d a i r y p r o d u c t s :

—s a t i s f a c t o r y ,i f i n a l l t h e s a m p l e u n i t s t h e e n t e r o t o x i n s a r e n o t d e t e c t e d ,

—u n s a t i s f a c t o r y ,i f t h e e n t e r o t o x i n s a r e d e t e c t e d i n a n y o f t h e s a m p l e u n i t s .

E n t e r o b a c t e r s a k a z a k i i i n d r i e d i n f a n t f o r m u l a e a n d d r i e d d i e t a r y f o o d s f o r s p e c i a l m e d i c a l p u r p o s e s i n t e n d e d f o r i n f a n t s b e l o w 6m o n t h s o f a g e :

—s a t i s f a c t o r y ,i f a l l t h e v a l u e s o b s e r v e d i n d i c a t e t h e a b s e n c e o f t h e b a c t e r i u m ,

—u n s a t i s f a c t o r y ,i f t h e p r e s e n c e o f t h e b a c t e r i u m i s d e t e c t e d i n a n y o f t h e s a m p l e u n i t s .

H i s t a m i n e i n f i s h e r y p r o d u c t s f r o m f i s h s p e c i e s a s s o c i a t e d w i t h a h i g h a m o u n t o f h i s t i d i n e :

—s a t i s f a c t o r y ,i f t h e f o l l o w i n g r e q u i r e m e n t s a r e f u l f i l l e d :

1.t h e m e a n v a l u e o b s e r v e d i s ≤m

___________

(1)T h e t e s t r e s u l t s m a y b e u s e d a l s o f o r d e m o n s t r a t i n g t h e e f f e c t i v e n e s s o f t h e h a z a r d a n a l y s i s a n d c r i t i c a l c o n t r o l p o i n t p r i n c i p l e s o r g o o d h y g i e n e p r o c e d u r e o f t h e p r o c e s s .

M 1

2005R2073—EN —27.12.2007—001.001—18

2.a m a x i m u m o f c /n v a l u e s o b s e r v e d a r e b e t w e e n m a n d M

3.n o v a l u e s o b s e r v e d e x c e e d t h e l i m i t o f M ,

—u n s a t i s f a c t o r y ,i f t h e m e a n v a l u e o b s e r v e d e x c e e d s m o r m o r e t h a n c /n v a l u e s a r e b e t w e e n m a n d M o r o n e o r m o r e o f t h e v a l u e s o b s e r v e d a r e >M .

M 1

2005R2073—EN —27.12.2007—001.001—

19

C h a p t e r 2.P r o c e s s h y g i e n e c r i t e r i a

2.1M e a t a n d p r o d u c t s t h e r e o f

M 1

2005R2073—EN —27.12.2007—001.001—

20

(1)n =n u m b e r o f u n i t s c o m p r i s i n g t h e s a m p l e ;c =n u m b e r o f s a m p l e u n i t s g i v i n g v a l u e s b e t w e e n m a n d M .(2)F o r p o i n t s 2.1.3-2.1.5m =M .(3)T h e m o s t r e c e n t e d i t i o n o f t h e s t a n d a r d s h a l l b e u s e d .(4)

T h e l i m i t s (m a n d M )s h a l l a p p l y o n l y t o s a m p l e s t a k e n b y t h e d e s t r u c t i v e m e t h o d .T h e d a i l y m e a n l o g s h a l l b e c a l c u l a t e d b y f i r s t t a k i n g a l o g v a l u e o f e a c h i n d i v i d u a l t e s t r e s u l t a n d t h e n c a l c u l a t i n g t h e m e a n o f t h e s e l o g v a l u e s .(5)T h e 50s a m p l e s s h a l l b e d e r i v e d f r o m 10c o n s e c u t i v e s a m p l i n g s e s s i o n s i n a c c o r d a n c e w i t h t h e s a m p l i n g r u l e s a n d f r e q u e n c i e s l a i d d o w n i n t h i s R e g u l a t i o n .(6)

T h e n u m b e r o f s a m p l e s w h e r e t h e p r e s e n c e o f s a l m o n e l l a i s d e t e c t e d .T h e c v a l u e i s s u b j e c t t o r e v i e w i n o r d e r t o t a k e i n t o a c c o u n t t h e p r o g r e s s m a d e i n r e d u c i n g t h e s a l m o n e l l a p r e v a l e n c e .M e m b e r S t a t e s o r r e g i o n s h a v i n g l o w s a l m o n e l l a p r e v a l e n c e m a y u s e l o w e r c v a l u e s e v e n b e f o r e t h e r e v i e w .(7)T h i s c r i t e r i o n s h a l l n o t a p p l y t o m i n c e d m e a t p r o d u c e d a t r e t a i l l e v e l w h e n t h e s h e l f -l i f e o f t h e p r o d u c t i s l e s s t h e n 24h o u r s .(8)E .c o l i i s u s e d h e r e a s a n i n d i c a t o r o f f a e c a l c o n t a m i n a t i o n .(9)

T h e s e c r i t e r i a a p p l y t o m e c h a n i c a l l y s e p a r a t e d m e a t (M S M )p r o d u c e d w i t h t h e t e c h n i q u e s r e f e r r e d t o i n p a r a g r a p h 3o f C h a p t e r I I I o f S e c t i o n V o f A n n e x I I I t o R e g u l a t i o n (E C )N o 853/2004o f t h e E u r o p e a n P a r l i a m e n t a n d o f t h e C o u n c i l .

M 1

最新食品中致病菌限量标准解读

最新食品中致病菌限量标准解读 致病菌指常见的致病性微生物,能够引起人或动物疾病。据统计,我国每年由食品中致病菌引起的食源性疾病报告病例数占全部报告的40%到50%。GB 29921-2013《食品安全国家标准食品中致病菌限量》于2013年12月26日发布,自2014年7月1日正式实施。该标准对控制食品中致病菌污染和预防微生物性食源性疾病具有划时代的意义。标准整合了500多项分散在不同食品标准中的致病菌限量规定,一定程度上解决了标准重复、交叉、矛盾或缺失等问题。 1.标准的定位 GB 29921属于通用食品安全国家标准。其他相关规定与本标准不一致的,应当按照本标准执行;其他食品标准中如有致病菌限量要求,应当引用本标准规定或与本标准保持一致。特别注意的是,部分在GB 29921实施前的行业标准、推荐性标准、食品安全国家标准或食品安全地方标准,如存在和GB 29921不一致的地方,应按照GB 29921执行。 比如,GB 19295-2011《食品安全国家标准速冻面米制品》发布和实施在GB 29921-2013之前。该标准对生制品、熟制品的致病菌均有规定,而GB 29921中只对即食类食品规定了致病菌限量,而对生制速冻面米制品并无致病菌限量要求,使用标准时需遵从GB 29921的要求。 依据原国家卫计委于2014年3月发布的关于GB 29921的问答,由于蜂蜜、脂肪和油及乳化脂肪制品、果冻、糖果、食用菌等食品或原料的微生物污染的风险很低,参照国际食品法典委员会(CAC)、国际食品微生物标准委员会(ICMSF)等国际组织的制标原则,暂不设置上述食品的致病菌限量;本标准在实施过程中,根据风险监测和风险评估结果,适时修订增加相关食品类别。在GB 29921后发布的部分食品安全标准又规定了致病菌限量,如GB 7096-2014《食用菌及其制品》规定即食食用菌致病菌限量应符合GB 29921中即食果蔬食品类的规定;GB 17401-2014《膨化食品》规定了致病菌限量应符合GB 29921中熟制粮食制品类的规定。因此,在使用GB 29921标准时要特别注意与该标准实施前后的相关标准衔接问题,尤其注意GB 29921未纳入的食品品种。 2.标准的适用范围和主要内容 适用范围: 适用于预包装食品,不适用于散装食品(非定量包装或无包装),也不适用于餐饮自制食品。广东省、香港等地发布过涉及散装即食食品的微生物控制标准或指引,包含多种指定食源性致病菌。其中广东规定了沙门氏菌、金黄色葡萄球菌、蜡样芽胞杆菌、单核细胞增生李斯特氏菌、副溶血性弧菌、大肠埃希氏菌O157的限量;香港规定了弯曲菌属、O157型大肠杆菌、沙门氏菌、霍乱弧菌、志贺氏菌、李斯特氏菌、副溶血性弧菌、金黄色葡萄球菌及其他凝固酶阳性葡萄球菌、产气荚膜梭状芽胞杆菌、蜡样芽胞杆菌共10种致病微生物的限量。国家卫生健康委2019年12月发布的《食品安全国家标准散装即食食品中致病菌限量》征求意见稿,适用于散装即食食品,但不适用于餐饮食品,不适用于现制现售的散装即食食品(指制作后立即销售,食品所有组分均经彻底加热处理,中心温度至少达到了70℃且持续时间不少于1 分钟)。征求意见稿覆盖了沙门氏菌、金黄色葡萄球菌、单核细胞增生李斯特氏菌、蜡样芽胞杆菌、副溶血性弧菌、产志贺毒素大肠埃希氏菌共6种致病菌,规定了相应的食品类别、限量要求和检验方法。 适用食品类别: 适用于肉制品、水产制品、即食蛋制品、粮食制品、即食豆类制品、巧克力类及可可制品、即食果蔬制品、饮料、冷冻饮品、即食调味品、坚果籽实制品等。上述食品均为即食食品。

常见的微生物检测方法

常见的微生物检测 方法

摘要:微生物的检测,无论在理论研究还是在生产实践中都具有重要的意义,本文分生长量测定法,微生物计数法,生理指标法和商业化快速微生物检测简要介绍了利用微生物重量,体积,大小,生理代谢物等指标的二十余种常见的检测方法,简要介绍了这些方法的原理,应用范围和优缺点。 概述: 一个微生物细胞在合适的外界条件下,不断的吸收营养物质,并按自己的代谢方式进行新陈代谢。如果同化作用的速度超过了异化作用,则其原生质的总量(重量,体积,大小)就不断增加,于是出现了个体的生长现象。如果这是一种平衡生长,即各细胞组分是按恰当的比例增长时,则达到一定程度后就会发生繁殖,从而引起个体数目的增加,这时,原有的个体已经发展成一个群体。随着群体中各个个体的进一步生长,就引起了这一群体的生长,这可从其体积、重量、密度或浓度作指标来衡量。微生物的生长不同于其它生物的生长,微生物的个体生长在科研上有一定困难,一般情况下也没有实际意义。微生物是以量取胜的,因此,微生物的生长一般指群体的扩增。微生物的生长繁殖是其在内外各种环境因素相互作用下的综合反映。因此生长繁殖情况就可作为研究各种生理生化和遗传等问题的重要指标,同

时,微生物在生产实践上的各种应用或是对致病,霉腐微生物的防治都和她们的生长抑制紧密相关。因此有必要介绍一下微生物生长情况的检测方法。既然生长意味着原生质含量的增加,因此测定的方法也都直接或间接的以次为根据,而测定繁殖则都要建立在计数这一基础上。微生物生长的衡量,能够从其重量,体积,密度,浓度,做指标来进行衡量。 生长量测定法 体积测量法:又称测菌丝浓度法。 经过测定一定体积培养液中所含菌丝的量来反映微生物的生长状况。方法是,取一定量的待测培养液(如10毫升)放在有刻度的离心管中,设定一定的离心时间(如5分钟)和转速(如5000 rpm),离心后,倒出上清夜,测出上清夜体积为v,则菌丝浓度为(10-v)/10。菌丝浓度测定法是大规模工业发酵生产上微生物生长的一个重要监测指标。这种方法比较粗放,简便,快速,但需要设定一致的处理条件,否则偏差很大,由于离心沉淀物中夹杂有一些固体营养物,结果会有一定偏差。 称干重法:

微生物菌种的分离和纯化方法

从混杂微生物群体中获得只含有某一种或某一株微生物的过程称为微生物分离与纯化。在分子生物学的研究及应用中,不仅需要通过分离纯化技术从混杂的天然微生物群中分离出特定的微生物,而且还必须随时注意保持微生物纯培养物的“纯洁”,防止其他微生物的混入。 1、用固体培养基分离和纯化 单个微生物在适宜的固体培养基表面或内部生长、繁殖到一定程度可以形成肉眼可见的、有一定形态结构的子细胞生长群体,称为菌落。当固体培养基表面众多菌落连成一片时,便成为菌苔。不同微生物在特定培养基上生长形成的菌落或菌苔一般都具有稳定的特征,可以成为对该微生物进行分类、鉴定的重要依据。大多数细菌、酵母菌、以及许多真菌和单细胞藻类能在固体培养基上形成孤立的菌落,采用适宜的平板分离法很容易得到纯培养。所谓平板,即培养平板的简称,它是指固体培养基倒入无菌平皿,冷却凝固后,盛固体培养基的平皿。这方法包括将单个微生物分离和固定在固体培养基表面或里面。固体培养基用琼脂或其它凝胶物质固化的培养基,每个孤立的活微生物体生长、繁殖形成菌落,形成的菌落便于移植。最常用的分离、培养微生物的固体培养基是琼脂固体培养基平板。这种由Kock建立的采用平板分离微生物纯培养的技术简便易行,100多年来一直是各种菌种分离的最常用手段。1.1 稀释倒平板法 首先把微生物悬液作一系列的稀释(如1:10、1:100、1:1000、1:10000),然后分别取不同稀释液少许,与已熔化并冷却至50℃左右的琼脂培养基混合,摇匀后,倾入灭过菌的培养皿中,待琼脂凝固后,制成可能含菌的琼脂平板,保温培养一定时间即可出现菌落。如果稀释得当,在平板表面或琼脂培养基中就可出现分散的单个菌落,这个菌落可能就是由一个细菌细胞繁殖形成的。随后挑取该单个菌落,或重复以上操作数次,便可得到纯培养。 1.2 涂布平板法 因为将微生物悬液先加到较烫的培养基中再倒平板易造成某些热敏感菌的死亡,且采用稀释倒平板法也会使一些严格好氧菌因被固定在琼脂中间缺乏氧气而影响其生长,因此在微生物学研究中常用的纯种分离方法是涂布平板法。其做法是先将已熔化的培养基倒入无菌平皿,

大学校园空气微生物污染调查

大学校园空气微生物污染调查 了解校园四季空气中微生物含量变化趋势与污染情况。方法采用撞击式采样器,在人员负荷最重、活动最频繁时,对某大学校园空气中细菌粒子和霉菌粒子含量进行检测。结果校园空气微生物含量在季节间有很大不同,细菌含量在夏季最高,霉菌含量高峰在夏秋两季。细菌浓度比较高的功能区有道路、寝室、食堂、超市、体育馆、微机室和教室。可吸入霉菌粒子占霉菌粒子总数的比例高于细菌粒子。结论校园空气微生物含量在多种因素的综合影响下,季节间和不同功能区之间均表现出明显的差异,存在一过性污染情况。 空气中的微生物往往吸附在颗粒物上形成生物粒子,随风飘荡,其中小粒径的生物粒子在疾病传播方面具有更大意义。研究表明,空气中微生物数量的多少与环境、清洁卫生状况、人员密度和活动情况、空气流通程度等因素有关[1,2]。高校校园是师生集中生活和学习的地方,普遍存在空气微生物污染问题[3,4]。加强对高校校园空气微生物的监测,对于了解校园卫生状况,加强环境卫生管理有着非常重要的参考意义。采用空气中生物粒子数(菌落总数,cfu)这一指示微生物指标对校园主要功能区空气质量进行生物学评价。 1.材料与方法 1.1 校园概况沈阳市内某高校,2001年新迁校址,主要建筑物距离城市南北向主干道约150~1000m。 1.2采样为全面反映校园内师生主要活动区域空气微生物状况,按功能不同将校园分成12个不同的功能区,即操场、道路、绿地、食堂、宿舍、教室、图书馆、微机室、实验室、超市、体育馆和办公室。参照《公共场所卫生监测技术规范》(GB/T 17220-1998),共设采样点126个。于2008-12,2009-03、2009-06、2009-09采样,分别代表冬、春、夏和秋四季,在各功能区人员负荷最重、活动最频繁时采样。参照《公共场所空气微生物检验方法》(GB/T18204.1-2000),采用撞击式采样。JWL-2型采样器有上、下两级,上级收集粒径 及以上的微生物粒子,下面级收集以下粒径的可吸入微生物粒子。采样高度为1.2~1.5m,采样时间1min,采样流量28.3L/min。细菌在37℃培养48h,霉菌在26℃培养72h 后,分别计数两级采样皿中的细菌菌落数和霉菌菌落数(cfu),也即捕获在采样皿中的空气细菌粒子数和霉菌粒子数。全年共采样2016份。 1.3培养基营养琼脂培养基和高盐查氏培养基购自北京奥博星生物技术有限责任公司。按使用说明配置、灭菌。使用Φ9cm平皿,每平皿倾注20ml培养基,冷却备用。 1.4主要仪器JWL-2 两级筛孔型撞击式空气微生物采样器,北京检测仪器有限公司;DXC-280B型不锈钢手提式灭菌器,上海申安医疗器械厂;YLN-30A菌落计数器,北京市亚力恩机电技术研究所;SHP-250型生化培养箱和MJP-250型霉菌培养箱,上海精宏实验设备有限公司;DB-4A控温电热板,金坛市天竟实验仪器厂,环境温度在零度以下采样时使用。 1.5 统计分析菌落计数后,按照公式n=N×1000/(Q×t)计算受检空气中微生物含量。式中:N—平皿菌落计数,个;Q—空气流量,L/min;t—采样时间,min。 1.6质量评价我国《室内空气质量标准》(GB/T18883-2002)规定,室内细菌菌落总数≤2500cfu/m3为合格。 2.结果 2.1空气中细菌粒子浓度及其变化趋势结果见表1,图1。 由表2可见,同样在冬季,室外空气中霉菌粒子含量明显低于其它三个季节,而在室内

微生物限量标准

微生物中文名食品中文名限量使用限制及备注中文 数据 采纳 日期 大肠菌群制冰厂及零售点的冰块(包装 冰) 0/100 mL 瓶装水、可食用冰及非瓶装饮料微生物 含量限值。 2009.4 埃希氏大肠杆菌制冰厂及零售点的冰块(包装 冰) 0/100 mL 瓶装水、可食用冰及非瓶装饮料微生物 含量限值。 2009.4 需氧菌落计数制冰厂及零售点的冰块(包装 冰) <500/ mL 瓶装水、可食用冰及非瓶装饮料微生物 含量限值。 2009.4 菌落总数植物蛋白饮料≤ 100(cf u/ml) 2003 大肠菌群植物蛋白饮料≤ 3(MPN /100m l) 2003 致病菌(沙门氏 菌、志贺氏菌、金黄色葡萄球菌) 植物蛋白饮料 不得检 出 2003 霉菌、酵母植物蛋白饮料≤ 20(cfu /ml) 2003 菌落总数鱼糜和虾糜制品≤ 3000(c fu/g) 即食类2005 大肠菌群鱼糜和虾糜制品≤ 30(MP N/100 g) 即食类2005

致病菌(沙门氏 菌、金黄色葡萄球菌、志贺氏菌) 鱼糜和虾糜制品 不得检 出 即食类2005 菌落总数鱼糜和虾糜制品≤ 50000( cfu/g) 非即食类2005 大肠菌群鱼糜和虾糜制品≤ 450(M PN/10 0g) 非即食类2005 致病菌(沙门氏 菌、金黄色葡萄球菌、志贺氏菌) 鱼糜和虾糜制品 不得检 出 非即食类2005 微生物鱼罐头符合罐 头食品 商业无 菌要求 2005 菌落总数油炸小食品类≤ 1000(c fu/ml) 2003 大肠菌群油炸小食品类≤ 30(MP N/100 ml) 2003 致病菌(沙门氏 菌、志贺氏菌、金黄色葡萄球菌) 油炸小食品类 不得检 出 2003 菌落总数婴幼儿配方粉及婴幼儿补充谷 粉 ≤ 30000( cfu/g) 婴儿配方粉1997 大肠菌群婴幼儿配方粉及婴幼儿补充谷 粉 ≤ 40/(M PN/10 0g) 婴儿配方粉1997

什么是微生物检验

什么是食品微生物检验 吴崇食质12级1班学号:20122629 微生物是个体难以用肉眼观察的一切微小生物之统称。微生物包括细菌、病毒、真菌、和少数藻类等。(但有些微生物是肉眼可以看见的,像属于真菌的蘑菇、灵芝等。)病毒是一类由核酸和蛋白质等少数几种成分组成的“非细胞生物”,但是它的生存必须依赖于活细胞。根据存在的不同环境分为空间微生物、海洋微生物等,按照细胞机构分类分为原核微生物和真核微生物。 微生物对人类最重要的影响之一是导致传染病的流行。在人类疾病中有50%是由病毒引起。微生物导致人类疾病的历史,也就是人类与之不断斗争的历史。在疾病的预防和治疗方面,人类取得了长足的进展,但是新现和再现的微生物感染还是不断发生,像大量的病毒性疾病一直缺乏有效的治疗药物。一些疾病的致病机制并不清楚。大量的广谱抗生素的滥用造成了强大的选择压力,使许多菌株发生变异,导致耐药性的产生,人类健康受到新的威胁。一些分节段的病毒之间可以通过重组或重配发生变异,最典型的例子就是流行性感冒病毒。每次流感大流行流感病毒都与前次导致感染的株型发生了变异,这种快速的变异给疫苗的设计和治疗造成了很大的障碍。而耐药性结核杆菌的出现使原本已近控制住的结核感染又在世界范围内猖獗起来。 微生物千姿百态,有些是腐败性的,即引起食品气味和组织结构发生不良变化。当然有些微生物是有益的,它们可用来生产如奶酪,面包,泡菜,啤酒和葡萄酒。微生物非常小,必须通过显微镜放大约1000 倍才能看到。比如中等大小的细菌,1000个叠加在一起只有句号那么大。想像一下一滴牛奶,每毫升腐败的牛奶中约有5千万个细菌,或者讲每夸脱牛奶中细菌总数约为50亿。也就是一滴牛奶中可能含有50 亿个细菌。 微生物能够致病,能够造成食品、布匹、皮革等发霉腐烂,但微生物也有有益的一面。最早是弗莱明从青霉菌抑制其它细菌的生长中发现了青霉素,这对医药界来讲是一个划时代的发现。后来大量的抗生素从放线菌等的代谢产物中筛选出来。抗生素的使用在第二次世界大战中挽救了无数人的生命。一些微生物被广

空气中微生物检测

空气中微生物检测 空气中微生物的检测 1。实验目的 本实验中使用的灭菌培养皿在空气中取样并培养一段时间以测定空气中的微生物。其实验意义在于: (1)了解空气中微生物的分布 (2)比较了普通实验室和无菌室空气中存在的微生物的数量和类型 (3)验证微生物实验中无菌操作的重要性二。实验原理 空气是人类维持正常活动的物质条件,与人类健康有着非常密切的关系。随着社会进入信息时代,空气微生物的采样和检测也得到了迅速发展。已经开发了各种快速、灵敏、特异和高度自动化的仪器。为了保持高质量的空气环境,应该使用正确和先进的空气监测方法。在我们周围环境中有大量的微生物空气也不例外。尽管空气不是微生物的良好栖息地然而,由于气流、灰尘和水滴的流动、人类和动物活动等原因,仍然存在相当数量的微生物。 中空气微生物的采集方法很多,主要采用空气微生物采样器采样监测,自然沉降采样法采样。本文介绍了各种采样方法的性能,以便正确选择各种采样方法。空气微生物采样主要涉及四个方面:采样器、采样介质、采样方法和检测程度。空气微生物采样器主要包括:冲击采样器、过滤空气采样器、离心空气采样器、旋风采样器、静电沉降采样器等 当空气中的单个微生物落在适合其生长和繁殖的固体培养基表面

时,在适当温度下培养一段时间后,每个分散的菌体或孢子将形成一个肉眼可见的细胞群体或菌落。通过观察不同大小和形状的菌落,可以大致识别空气中存在的微生物类型。本实验通过检测普通实验室和无菌间空气中存在的微生物,来判断无菌间的消毒效果,了解空气中常见的微生物群。三。实验装置和仪器 1。实验仪器 (1)无菌板,组数(2)酒精灯,恒温箱数×1 (3),数量×2 (4)高压釜(5)干热灭菌器(6)冰箱 (7)板(直径9厘米)(8)量筒(9)烧瓶(10)酸度计2。实验所需试剂 (1)蛋白胨,量10g (2)牛肉膏,量3g (3)氯化钠5g (4)琼脂15-20g (5)蒸馏水1000毫升 4,实验步骤 1。琼脂培养基制备方法:将蛋白胨、牛肉膏、氯化钠、琼脂和蒸馏水混合,加热溶解 ,调至7.4,过滤分装,高压灭菌121℃和20min,用自然沉降法测定时,将约15mL倒入灭菌板中,制成营养琼脂板2.倒置板:培养基按常规方法制备,分成三角瓶,高压灭菌备用使用 前,将培养基融化,冷却至50℃左右,倒入几个盘子备用。 3。检测:首先打开无菌室内的紫外线灯,照射15分钟后关闭。打开上面浓缩了 的无菌平板的皿盖,将皿盖暴露在无菌室空间和普通实验室空间中,分别不移动5min和30min后盖上皿盖每个培养基的平板要求在每个

食品中致病菌限量问答

《食品中致病菌限量》(GB29921-2013)问答 中华人民共和国国家卫生和计划生育委员会2014-03-06 一、标准的制定目的 致病菌是常见的致病性微生物,能够引起人或动物疾病。食品中的致病菌主要有沙门氏菌、副溶血性弧菌、大肠杆菌、金黄色葡萄球菌等。据统计,我国每年由食品中致病菌引起的食源性疾病报告病例数约占全部报告的40%至50%。 《食品安全法》规定,食品安全标准应当包括食品、食品相关产品中的致病性微生物、农药残留、兽药残留、重金属、污染物质以及其他危害人体健康物质的限量规定。目前,我国涉及食品致病菌限量的现行食品标准共计500多项,标准中致病菌指标的设臵存在重复、交叉、矛盾或缺失等问题。 为控制食品中致病菌污染,预防微生物性食源性疾病发生,同时整合分散在不同食品标准中的致病菌限量规定,国家卫生计生委委托国家食品安全风险评估中心牵头起草《食品中致病菌限量》(GB29921-2013,以下简称GB29921)。标准经食品安全国家标准审评委员会审查通过,于2013年12月26日发布,自2014年7月1日正式实施。 GB29921属于通用标准,适用于预包装食品。其他相关规定与本标准不一致的,应当按照本标准执行。其他食品标准中如有致病菌限量要求,应当引用本标准规定或者与本标准保持一致。 二、标准的实施要求

GB29921实施日期(2014年7月1日)前,允许并鼓励食品生产经营单位按照本标准执行。在标准实施日期之后,食品生产经营单位、食品安全监管机构和检验机构应按照本标准执行。在实施日期前已生产的食品可在保质期内继续销售。进口食品的标准执行时间应按照相关规定执行。致病菌检验应按照GB29921引用的检验方法执行。 食品生产经营者应当严格执行食品生产经营规范标准或采取相应控制措施,严格生产经营过程的微生物控制,确保产品符合GB29921规定。 国家卫生计生委将组织对GB29921实施情况进行跟踪评价,根据评价情况适时修订完善标准。 三、标准的制定原则与制定过程 (一)以健康保护为目的。GB29921制定目的是控制食品中致病菌污染,预防食源性疾病。起草组分析我国2005年至2011年食源性疾病发生原因,参照国际管理经验,对“致病菌-食品”组合开展风险评估,根据风险监测和风险评估结果,优先制定高危食品中的重要致病菌限量,降低高危致病菌导致食源性疾病的风险。 (二)以科学为依据。起草组在食品中致病菌风险监测和风险评估基础上,综合分析相关致病菌或其代谢产物可能造成的健康危害、原料中致病菌情况、食品加工、贮藏、销售和消费等各环节致病菌变化情况,充分考虑各类食品的消

微生物检验(完整版)

微生物检验(完整版) 名解 微生物:是一群个体微小结构简单肉眼不能看见的微小生物的总称 种:亲缘关系较近的微生物群体在进化发育阶段上有一定的共同形态和生理特征 微生物学:生物学的一个分支是研究微生物在一定条件下的形态结构生理生化遗传变异特性及微生物的进化分类生态等生命活动规律以及微生物之间与人类动植物自然界互相关系的一门科学 抗生素:是由某些微生物在代谢过程中产生的能抑制或杀灭某些其他微生物和肿瘤细胞的微量生物活性物质 细菌素:是某些细菌菌株产生的一类具有抗菌作用的蛋白质 条件致病菌:正常菌群在宿主体内具有相对稳定性一般不致病 消毒:指杀死物体上的病原微生物但不一定能杀死细菌芽孢的方法 灭菌:指杀灭物体上所有的微生物的方法 防腐:指防止或抑制微生物生长繁殖的方法 无菌:指没有货的微生物的存在 质粒:是细菌染色体外的遗传物质也是环状闭合的双联DNA分子比染色体小存在于细胞质中可自主复制 突变:是指细菌遗传物质的机构发生突然而稳定的改变所致的变异现象可遗传给后代 基因转移:外源性物质由供体菌转入受体细胞内的过程 基因重组:供体菌的基因进入受体菌细胞并在其中自行复制与表达或矛受体菌DNA整合在一起的过程 病毒:是一类个体微小结构简单只含一种核酸只能在活的易感细胞内以复制方式增殖的

非细胞型微生物 复制周期:病毒的增殖被人为分成吸附穿入脱壳生物合成装配成熟与释放七个步骤的完整过程 缺陷病毒:是指因病毒基因组不完整或因基因某一点改变而不能进行正常增殖的病毒 顿挫感染:病毒进入宿主细胞若细胞缺乏病毒复制所需的酶能量和必要成分等则病毒无法合成自身成分不能够装配和释放子代病毒的现象 干扰现象:两种病毒感染同一种细胞时可发生一种病毒抑制另一种病毒增殖的现象 人工自动免疫:是将疫苗等免疫原接种于人体刺激机体免疫系统产生特异性免疫应答使机体获得特异性免疫力 人工被动免疫:是指注射含某种病毒特异性中和抗体的免疫血清等一系列细胞因子是机体立即获得特异性免疫 干扰素:是由病毒或干扰素诱生剂作用于中性粒细胞成纤维细胞或免疫细胞产生的一种糖蛋白 致病性:一定种类的病原微生物在一定的条件下能在特殊的宿主体内引起特定疾病的能力半数致死量:在规定时间内通过一定途径能使一定体重或年龄的某种动物半数死亡或感染需要的最小病原体数量或毒素量 急性感染:发作突然病程较短一般是数天或数周 局部感染:病原体侵入机体后局限就在一定部位生长繁殖引起病变的一种感染类型 毒血症:致病菌侵入宿主体后只在机体局部生长繁殖病菌不进入血液循环但其产生的外毒素入血引起特殊的毒性症状 败血症:致病菌侵入血流后在其中大量繁殖并产生毒性产物引起全身性毒性症状 内毒素血症:革兰阴性菌侵入血流并在其中大量繁殖崩解后释放出大量毒素也可有病灶

空气细菌总数的测定

空气细菌总数的测定 一、实验原理 培养基是供微生物生长、繁殖、代谢的混合养料。由于微生物具有不同的营养类型,对营养物质的要求也各不相同,加之实验和研究的目的不同,所以培养基的种类很多,使用的原料也各有差异,但从营养角度分析,培养基中一般含有微生物所必需的碳源、氮源、无机盐、生长素以及水分等。另外,培养基还应具有适宜的pH值、一定的缓冲能力、一定的氧化还原电位及合适的渗透压。 任何一种培养基一经制成就应及时彻底灭菌,以备纯培养用。一般培养基的灭菌采用高压蒸汽灭菌。 高压灭菌的原理是:在密闭的蒸锅内,其中的蒸汽不能外溢,压力不断上升,使水的沸点不断提高,从而锅内温度也随之增加。在0.1MPa的压力下,锅内温度达121℃。在此蒸汽温度下,可以彻底高效杀死各种细菌及其高度耐热的原理。 空气是人类赖以生存的必须环境,也是微生物借以扩散的媒介。空气中存在着细菌、真菌、病毒、放线菌等多种微生物粒子,这些微生物粒子是空气污染物的重要组成部分。空气微生物主要来自于地面及实施、人和动物的蹑手呼吸道、皮肤和毛发等,它附着在空气气溶胶细小颗粒物表面,可较长时间停留在空气中。某些微生物还可以随着空气中细小颗粒穿过人体肺癌存留在肺的深处,给身体健康带来严重危害,也可以随着空气中细小颗粒物被输送到较远地区,给人体带来许多传染性的疾病和上呼吸道疾病。因此,空气微生物含量多少可以反映所在区域的空气质量,是空气环境污染的一个重要参数评价空气的清洁程度,需要测定空气中的微生物数量和空气污染微生物。 ----测定方法--平皿沉降法 二、测定原理 空气中飘浮着各种微生物,将盛有无菌培养基的平皿放于监测点上,暴露5min,空气中的细菌便会落到培养基上,然后在37°C恒温箱中培养24h,计数每个平皿表面的菌落数,由于一个菌落由一个细菌繁殖而来,菌落总数便可认为是细菌总数。 三、试剂 营养琼脂 1、成分 A蛋白胨 1g B牛肉膏 0.3g

《食品中致病菌限量》标准解读

《食品中致病菌限量》标准解读 致病菌指常见的致病性微生物,能够引起人或动物疾病。据统计,我国每年由食品中致病菌引起的食源性疾病报告病例数占全部报告的40%到50%。GB 29921-2013《食品安全国家标准食品中致病菌限量》于2013年12月26日发布,自2014年7月1日正式实施。该标准对控制食品中致病菌污染和预防微生物性食源性疾病具有划时代的意义。标准整合了500多项分散在不同食品标准中的致病菌限量规定,一定程度上解决了标准重复、交叉、矛盾或缺失等问题。 1.标准的定位 GB 29921属于通用食品安全国家标准。其他相关规定与本标准不一致的,应当按照本标准执行;其他食品标准中如有致病菌限量要求,应当引用本标准规定或与本标准保持一致。特别注意的是,部分在GB 29921实施前的行业标准、推荐性标准、食品安全国家标准或食品安全地方标准,如存在和GB 29921不一致的地方,应按照GB 29921执行。 比如,GB 19295-2011《食品安全国家标准速冻面米制品》发布和实施在GB 29921-2013之前。该标准对生制品、熟制品的致病菌均有规定,而GB 29921中只对即食类食品规定了致病菌限量,而对生制速冻面米制品并无致病菌限量要求,使用标准时需遵从GB 29921的要求。 依据原国家卫计委于2014年3月发布的关于GB 29921的问答,由于蜂蜜、脂肪和油及乳化脂肪制品、果冻、糖果、食用菌等食品或原料的微生物污染的风险很低,参照国际食品法典委员会(CAC)、国际食品微生物标准委员会(ICMSF)等国际组织的制标原则,暂不设置上述食品的致病菌限量;本标准在实施过程中,根据风险监测和风险评估结果,适时修订增加相关食品类别。在GB 29921后发布的部分食品安全标准又规定了致病菌限量,如GB 7096-2014《食用菌及其制品》规定即食食用菌致病菌限量应符合GB 29921中即食果蔬食品类的规定;GB 17401-2014《膨化食品》规定了致病菌限量应符合GB 29921中熟制粮食制品类的规定。因此,在使用GB 29921标准时要特别注意与该标准实施前后的相关标准衔接问题,尤其注意GB 29921未纳入的食品品种。 2.标准的适用范围和主要内容 适用范围: 适用于预包装食品,不适用于散装食品(非定量包装或无包装),也不适用于餐饮自制食品。 广东省、香港等地发布过涉及散装即食食品的微生物控制标准或指引,包含多种指定食源性致病菌。其中广东规定了沙门氏菌、金黄色葡萄球菌、蜡样芽胞杆菌、单核细胞增生李斯特氏菌、副溶血性弧菌、大肠埃希氏菌O157的限量;香港规定了弯曲菌属、O157型大肠杆菌、沙门氏菌、霍乱弧菌、志贺氏菌、李斯特氏菌、副溶血性弧菌、金黄色葡萄球菌及其他凝固酶阳性葡萄球菌、产气荚膜梭状芽胞杆菌、蜡样芽胞杆菌共10种致病微生物的限量。国家卫生健康委2019年12月发布的《食品安全国家标准散装即食食品中致病菌限量》征求意见稿,适用于散装即食食品,但不适用于餐饮食品,不适用于现制现售的散装即食食品(指

实验3环境微生物的检测

实验三环境微生物的检测 一、实验目的 1.了解周围环境中微生物的分布情况。 2.懂得无菌操作在微生物实验中的重要性。 3.了解四大类微生物的菌落特征。 二、实验原理 在我们周围的环境中存在着种类繁多的、数量庞大的微生物。土壤、江河湖海、尘埃、空气、各种物体的表面以及人和动物体的口腔、呼吸道、消化道等都存在着各种微生物。由于它们体积微小,人们用肉眼无法观察到它们个体的存在。但是只要稍加留意,我们就可以在发霉的面包、朽木上看到某些微生物群体。这些现象表明,自然界只要有微生物可以利用的物质和环境条件,微生物就可以在其上生长繁殖。据此,我们在实验室里就可以用培养基来培养微生物。 培养基是用人工配制的、适合微生物生长繁殖和产生代谢产物用的混合养料。其中含有微生物所需要的六大营养要素:碳源、氮源、无机盐、生长因子、气体和水分。此外,根据不同的微生物的要求,在配制培养基时还需用酸液或碱液调节至适宜的pH。配制好的培养基必须进行灭菌。所谓灭菌是指采用各类的物理或化学因素,使物体内外的所有微生物丧失其生长繁殖能力的措施。经过灭菌后的物体是无菌的。消毒是与灭菌完全不同的概念,它是指用较温和的物理因素杀死物体表面和内部病原微生物的一种常用的卫生措施。 灭菌的方法较多,广泛使用的是高温灭菌,其中最常用的是高压蒸汽灭菌法。此法是把待灭菌的物品放在一个可密闭的加压蒸汽灭菌锅中进行的。在1.05kg/cm2的蒸汽压力下,温度可达121℃。一般只要维持15~20min,就可杀死一切微生物的营养体和它们的各种孢子。 微生物的接种技术是生物科学研究中的一项最基本操作技术。为了确保纯种不被杂菌污染,在整个接种过程中,必须进行严格的无菌操作。在实验过程中必须牢固树立无菌概念,经常保持实验台及周围环境的清洁,严格无菌操作,避免杂菌的污染,这是保证实验成功的必要条件。

最新微生物对污染物的降解和转化

微生物对污染物的降解和转化 ?有机污染物生物净化(天然物质、人工合成物质) ?无机污染物生物净化 第一节有机污染物的生物净化机理 ?净化本质——微生物转化有机物为无机物 ?依靠——好氧分解与厌氧分解 一、好氧分解 ?细菌是其中的主力军 ?原理:好氧有机物呼吸 ? C → CO2 + 碳酸盐和重碳酸盐 ? H → H2O ? N → NH3→ HNO2→ HNO3 ? S → H2SO4 ? P → H3PO4 ?二、厌氧分解?厌氧细菌 ?原理:发酵、厌氧无机盐呼吸C → RCOOH(有机酸)→CH4 + CO2 ?N → RCHNH2COOH → NH3(臭味) + 有机酸(臭味) ?S → H2S(臭味) ?P → PO 3- 4 ?水体自净的天然过程中 厌氧分解(开始)→好氧分解(后续)第二节各类有机污染物的转化 一、碳源污染物的转化

?包括糖类、蛋白质、脂类、石油和人工合成的有机化合物等。 1.纤维素的转化 ?β葡萄糖高聚物,每个纤维素分子含1400~10000个葡萄糖基(β1-4糖苷键)。 ?来源:棉纺印染废水、造纸废水、人造纤维废水及城市垃圾等,其中均含有大量纤维素。 A.微生物分解途径 B.分解纤维素的微生物 ?好氧细菌——粘细菌、镰状纤维菌和纤维弧菌 ?厌氧细菌——产纤维二糖芽孢梭菌、无芽孢厌氧分解菌及嗜热纤维芽孢梭菌。?放线菌——链霉菌属。 ?真菌——青霉菌、曲霉、镰刀霉、木霉及毛霉。 ?需要时可以向有菌种库的研究机构购买或自行筛选。 2.半纤维素的转化 ?存在于植物细胞壁的杂多糖。造纸废水和人造纤维废水中含半纤维素。 ?分解过程 ?分解纤维素的微生物大多数能分解半纤维素。 ?许多芽孢杆菌、假单胞菌、节细菌及放线菌能分解半纤维素。霉菌有根霉、曲霉、小克银汉霉、青霉及镰刀霉。 3.木质素的转化自然界中哪些微生物能够进行木质素的降解呢??确证的只有真菌中的黄孢原毛平革菌,疑似的有软腐菌。 黄孢原平毛革菌(Phanerochaete chrysosprium)是白腐真菌的一种,隶属于担子菌纲、同担子菌亚纲、非褶菌目、丝核菌科。 白腐—树皮上木质素被该菌分解后漏出白色的纤维素部分。*木质素降解的意义何在呢?(二)油脂的转化

空气中微生物检测1

一、空气中微生物的检测 一、实验目的 1了解空气中微生物的分布状况,学习空气采样方法 2掌握空气中微生物的检测方法 二实验原理 空气是人类赖以生存的必须环境,也是微生物借以扩散的媒介。空气中存在着细菌、真菌、病毒、放线菌等多种微生物粒子,这些微生物粒子是空气污染物的重要组成部分。空气微生物主要来自于地面及实施、人和动物的蹑手呼吸道、皮肤和毛发等,它附着在空气气溶胶细小颗粒物表面,可较长时间停留在空气中。某些微生物还可以随着空气中细小颗粒穿过人体肺癌存留在肺的深处,给身体健康带来严重危害,也可以随着空气中细小颗粒物被输送到较远地区,给人体带来许多传染性的疾病和上呼吸道疾病。因此,空气微生物含量多少可以反映所在区域的空气质量,是空气环境污染的一个重要参数评价空气的清洁程度,需要测定空气中的微生物数量和空气污染微生物。测定的细菌指标有细菌总数和绿色链球菌,在必要时则测病原微生物。 空气并非微生物的繁殖场所,空气中缺乏水分和营养,紫外线的照射对微生物也有致死作用。微生物产生的孢子本身也可以飘浮到空气中,形成“气溶胶”,借风力传播。 空气中的微生物中,真菌的孢子数量最多,细菌较少。而且藻类、酵母菌、病毒都会存在于空气中。 目前,还无统一的关于空气的卫生学指标,一般以室内1m3 空气中细菌总数为50~1,000个以上作为空气污染的指标。 病原菌在空气中一般很易死亡,但结核菌、白喉杆菌、葡萄球菌、链球菌、肺炎双球菌、炭疽杆菌、流感病毒和脊髓灰质炎病毒等,也可以在空气中存活一段时间。 尘埃多的地方,如畜舍、公共场所、医院、城市街道的空气中,微生物数量较多。高山、海洋、森林、积雪的山脉和高纬度地带的空气中,微生物较少。 在本次实验中测量空气中微生物含量,主要是利用空气的自然沉降法,也有其它方法,如撞击法,过滤法等。 三实验器材 电炉,培养基,培养箱,无菌台 四实验步骤

微生物的培养与应用综合测试-人教版高中生物选修1检测练习

专题综合测试(二) 时间:90分钟满分:100分 一、选择题(每小题2分,共40分) 1.关于培养基的配制说法不正确的是() A.在配制培养乳酸杆菌的培养基时,需加入维生素 B.微生物的适应性强,配制培养基时可以不考虑pH C.虽然各种培养基的具体配方不同,但一般都含有碳源、氮源、水和无机盐 D.配制培养基时要注意各种养分的浓度和比例 答案 B 解析乳酸杆菌自身不能合成维生素,而维生素又是维持其生命活动不可缺少的,故需在培养基中添加,A正确;pH影响微生物的生长和代谢,配制培养基时pH一定要适宜,B错误;微生物也是由C、H、O、N、P、S等元素组成,这些元素最终来自外界环境中的各种无机化合物和有机化合物,可归纳为碳源、氮源、生长因子、水、无机盐等,但配制时要注意各种养分的浓度和比例,C、D正确。 2.下列关于培养基的叙述中,正确的是() A.微生物在液体培养基表面生长可以形成肉眼可见的菌落 B.培养霉菌与细菌时培养基的pH基本一致 C.一般培养基都需加入碳源、氮源、无机盐和水 D.蛋白胨只能为微生物提供碳源和维生素 答案 C 解析微生物在固体培养基表面生长可以形成肉眼可见的菌落,A错误;培养霉菌时需将培养基的pH调至酸性,培养细菌时需将pH调至中性或微碱性,B错误;培养基一般都含有水、碳源、氮源和无机盐等成分,C正确;蛋白胨可为微生物提供氮源、碳源和维生素,D错误。 3.下列关于细菌的叙述,错误的是() A.硝化细菌能以NH3作为氮源和能源物质 B.某些细菌可以利用光能固定CO2合成有机物

C.生长因子是某些细菌生长过程中需要额外补充的营养物质 D.含伊红美蓝试剂的培养基不能用来鉴别牛奶中的大肠杆菌 答案 D 解析硝化细菌可以利用氧化氨释放的能量来合成有机物,氨含有氮元素可以提供氮源,A正确;光合细菌可以利用光能进行光合作用,固定CO2合成有机物,B正确;某些微生物不能合成一些生长所必需的物质,必须从外界摄取这些营养物质,C正确;含伊红美蓝试剂的培养基可以用来鉴别牛奶中的大肠杆菌,如果菌落呈黑色,并带有金属光泽,说明牛奶中含有大肠杆菌,D错误。 4.下表表示在不同培养基中某细菌的生长繁殖情况(A、B、C、H、I、J、K、M为培养基的成分,“+”表示生长,“-”表示不生长),请分析下列哪种物质细菌不能合成() 答案 C 解析比较不同培养基的添加物,凡添加了物质K的培养基,细菌都能生长,反之则不能生长,说明物质K是细菌不能合成的,C正确。 5.下列与微生物培养有关的说法,不正确的是() A.高压蒸汽灭菌的原理是高温破坏了细胞内的蛋白质,影响其生命活动B.培养基在50 ℃时搁置斜面以及将平板倒置放入培养箱中培养都与消毒灭菌无关 C.在微生物培养过程中,除考虑营养条件外,还要考虑pH、温度和渗透压等条件 D.每个菌落由大量的各种细菌组成,菌落的特征可以作为菌种鉴定的重要依据 答案 D 解析菌落内部为同种细菌,菌落的特征可以作为菌种鉴定的重要依据,D 错误;高压蒸汽灭菌的原理是高温破坏微生物体内蛋白质的空间结构,从而影响

微生物的分离和纯化

实验十四微生物的分离和纯化 一、目的要求 掌握倒平板的方法和几种分离纯化微生物的基本操作技术。 二、基本原理 在土壤、水、空气或人及动、植物体中,不同种类的微生物绝大多数都是混杂生活在一起,当我们希望获得某一种微生物时,就必须从混杂的微生物类群中分离它,以得到只含有这一种微生物的纯培养,这种获得纯培养的方法称为微生物的分离与纯化。 为了获得某种微生物的纯培养,一般是根据该微生物对营养、酸碱度、氧等条件要求不同,而供给它适宜的培养条件,或加入某种抑制剂造成只利于此菌生长,而抑制其他菌生长的环境,从而淘汰其他一些不需要的微生物,再用稀释涂布平板法或稀释混合平板法或平板划线分离法等分离、纯化该微生物,直至得到纯菌株。 土壤是微生物生活的大本营,在这里生活的微生物无论是数量和种类都是极其多样的,因此,土壤是我们开发利用微生物资源的重要基地,可以从其中分离、纯化到许多有用的菌株。 三、器材 高氏1号琼脂培养基,肉膏蛋白胨琼脂培养基,马丁氏琼脂培养基,盛9ml无菌水的试管,盛90ml无菌水并带有玻璃珠的三角烧瓶,无菌玻璃涂棒,无菌吸管,接种环,10%酚,无菌培养皿,链霉素,土样等。 四、操作步骤 1.稀释涂布平板法 (1)倒平板将肉膏蛋白胨培养基、高氏1号琼脂培养基、马丁氏琼脂培养基溶化,待冷至55—60℃时,向高氏1号琼脂培养基中加入10%酚数滴,向马丁氏培养基中加入链霉素溶液,使每毫升培养基中含链霉素30μg。然后分别倒平板,每种培养基倒三皿,其方法是右手持盛培养基的试管或三角烧瓶,置火焰旁边,左手拿平皿并松动试管塞或瓶塞,用手掌边缘和小指、无名指夹住拔出,如果试管内或三角烧瓶内的培养基一次可用完,则管塞或瓶塞不必夹在手指中。试管(瓶)口在火焰上灭菌,然后左手将培养皿盖在火焰附近打开一缝,迅速倒入培养基约15ml,加盖后轻轻摇动培养皿,使培养基均匀分布,平置于桌面上,待凝后即成平板。也可将平皿放在火焰附近的桌面上,用左手的食指和中指夹住管塞并打开培养皿,再注入培养基,摇匀后制成平板,如图Ⅶ-1所示。最好是将平板放室温2—3天,或 37℃培养24小时,检查无菌落及皿盖无冷凝水后再使用。 (2)制备土壤稀释液称取土样10g,放入盛90ml无菌水并带有玻璃珠的三角烧瓶中,振摇约20分钟,使土样与水充分混合,将菌分散。用一支1ml无菌吸管从中吸取1ml土壤悬液注入盛有9ml无菌水的试管中,吹吸三次,使充分混匀。然后再用一支1ml无菌吸管从

空气细菌总数的测定教案资料

空气细菌总数的测定

空气细菌总数的测定 一、实验原理 培养基是供微生物生长、繁殖、代谢的混合养料。由于微生物具有不同的营养类型,对营养物质的要求也各不相同,加之实验和研究的目的不同,所以培养基的种类很多,使用的原料也各有差异,但从营养角度分析,培养基中一般含有微生物所必需的碳源、氮源、无机盐、生长素以及水分等。另外,培养基还应具有适宜的pH值、一定的缓冲能力、一定的氧化还原电位及合适的渗透压。 任何一种培养基一经制成就应及时彻底灭菌,以备纯培养用。一般培养基的灭菌采用高压蒸汽灭菌。 高压灭菌的原理是:在密闭的蒸锅内,其中的蒸汽不能外溢,压力不断上升,使水的沸点不断提高,从而锅内温度也随之增加。在0.1MPa的压力下,锅内温度达121℃。在此蒸汽温度下,可以彻底高效杀死各种细菌及其高度耐热的原理。 空气是人类赖以生存的必须环境,也是微生物借以扩散的媒介。空气中存在着细菌、真菌、病毒、放线菌等多种微生物粒子,这些微生物粒子是空气污染物的重要组成部分。空气微生物主要来自于地面及实施、人和动物的蹑手呼吸道、皮肤和毛发等,它附着在空气气溶胶细小颗粒物表面,可较长时间停留在空气中。某些微生物还可以随着空气中细小颗粒穿过人体肺癌存留在肺的深处,给身体健康带来严重危害,也可以随着空气中细小颗粒物被输送到较远地区,给人体带来许多传染性的疾病和上呼吸道疾病。因此,空气微生物含量多少可以反映所在区域的空气质量,是空气环境污染的一个重要参数评价空气的清洁程度,需要测定空气中的微生物数量和空气污染微生物。 ----测定方法--平皿沉降法 二、测定原理 空气中飘浮着各种微生物,将盛有无菌培养基的平皿放于监测点上,暴露 5min,空气中的细菌便会落到培养基上,然后在37°C恒温箱中培养24h,计数每个平皿表面的菌落数,由于一个菌落由一个细菌繁殖而来,菌落总数便可认为是细菌总数。 三、试剂 营养琼脂 1、成分 A蛋白胨 1g

微生物检测手段及注意事项

微生物检测手段及注意事项

微生物检测手段及注意事项 微生物的检测,无论在理论研究还是在生产实践中都具有重要的意义,本文对生长量测定法、微生物计数法、生理指标法和商业化快速微生物检测简要介绍了利用微生物重量,体积,大小,生理代谢物等指标的二十余种常用的检测方法,简要介绍了这些方法的原理,应用范围和优缺点。 一个微生物细胞在合适的外界条件下,不断的吸收营养物质,并按自己的代谢方式进行新陈代谢。如果同化作用的速度超过了异化作用,则其原生质的总量(重量,体积,大小)就不断增加,于是出现了个体的生长现象。如果这是一种平衡生长,即各细胞组分是按恰当的比例增长时,则达到一定程度后就会发生繁殖,从而引起个体数目的增加,这时,原有的个体已经发展成一个群体。随着群体中各个个体的进一步生长,就引起了这一群体的生长,这可从其体积、重量、密度或浓度作指标来衡量。微生物的生长不同于其他生物的生长,微生物的个体生长在科研上有一定困难,通常情况下也没有实际意义。微生物是以量取胜的,因此,微生物的生长通常指群体的扩增。微生物的生长繁殖是其在内外各种环境因素相互作用下的综合反映。因此生长繁殖情况就可作为研究各种生理生化和遗传等问题的重要指标,同时,微生物在生产实践上的各种应用或是对致病,霉腐微生物的防治都和他们的生长抑制紧密相关。所以有必要介绍一下微生物生长情况的检测方法。既然生长意味着原生质含量的增加,所以测定的方法也都直接或间接的以次为根据,而

测定繁殖则都要建立在计数这一基础上。微生物生长的衡量,可以从其重量,体积,密度,浓度,做指标来进行衡量。 1. 微生物计量法 1.1 体积测量法 又称测菌丝浓度法,通过测定一定体积培养液中所含菌丝的量来反映微生物的生长状况。方法是,取一定量的待测培养液(如10 mL)放在有刻度的离心管中,设定一定的离心时间(如5 min)和转速(如5000 rpm),离心后,倒出上清夜,测出上清夜体积为v,则菌丝浓度为(10-v)/10。菌丝浓度测定法是大规模工业发酵生产上微生物生长的一个重要监测指标。这种方法比较粗放,简便,快速,但需要设定一致的处理条件,否则偏差很大,由于离心沉淀物中夹杂有一些固体营养物,结果会有一定偏差。 称干重法 可用离心或过滤法测定。一般干重为湿重的10~20%。在离心法中,将一定体积待测培养液倒入离心管中,设定一定的离心时间和转速,进行离心,并用清水离心洗涤1~5次,进行干燥。干燥可用烘箱在105 ℃或100 ℃下烘干,或采用红外线烘干,也可在80 ℃或40 ℃下真空干燥,干燥后称重。如用过滤法,丝状真菌可用滤纸过滤,细菌可用醋酸纤维膜等滤膜过滤,过滤后用少量水洗涤,在40 ℃下进行真空干燥。称干重发法较为烦琐,通常获取的微生物产品为菌体时,常采用这种方法,如活性干酵母(Activity Dry Yeast, ADY),一些以微生物菌体为活性物质的饲料和肥料。

相关文档
最新文档