澳大利亚李斯特菌控制指南ADASC_-_Listeria_control_manual.pdf

Australian Manual for Control of Listeria in the Dairy Industry ADASC July 1999 Listeria Manual Table of Contents Page 1.Foreword 4 2.Purpose and Scope 5 3.Summary of Company Responsibilities 6 4.Background on Listeria 7 4.1 Introduction 7 4.2 Significance in the Dairy Industry 8 4.3 Prevalence of Listeria in the Dairy Industry 8 4.3.1 On Farm 8 4.3.2 Factory Environments 9 4.3.3 Milk and Dairy Products 9 4.4 Occurrence of Listeria in Dairy Factory Environments 9 5.Listeria Prevention Procedures 10 5.1 Introduction 10 5.2 Steps to Control Listeria Entry to Plant Areas 10 5.3 Steps to Control Listeria in the Processing Area 11 5.3.1 Effective Pasteurisation 11 5.3.2 Post-Pasteurisation Contamination 12 5.3.3 A Check List for Post-Pasteurisation Contamination 18 6.Management of Listeria Contamination 19 6.1 Notification 19 6.2 Clearance Program 19 6.2.1 Listeria spp in Product 19 6.2.2 Listeria monocytogenes in Product 20 6.3 Procedure for Securing Contaminated Product 21 7.Export Requirements 23 8.Disposal of Contaminated Product 24 8.1 Product Reprocessing 24 8.1.1 General Principles 24 8.1.2 Conditions for Approval 24 8.1.3 Procedure 25 8.2 Sale of Reprocessed Product 25 8.3 Destruction of Listeria monocytogenes Contaminated Product 25 ADASC LISTERIA REQUIREMENTS.DOC ADASC 1999 Page 2 of 46 Version 2-January 2000 前言目的和范围公司职责背景简介在乳品行业的意义在乳品行业李斯特菌的普遍性在农场工厂环境生乳及乳制品在乳品厂环境中李斯特菌发生李斯特预防程序简介植物入口控制步骤在加工区控制步骤有效杀菌消毒后污染消毒后污染检查列表李斯特菌污染管理通知清洁程序Listeria Manual Table of Contents Page 9.Sampling for Listeria Testing 26 9.1 Introduction 26 9.2 Sample Size and Compositing 26 9.3 Cheese 26 9.4 Pasteurised Milk 26 9.5 Other Products 26 9.6 Stage of Manufacture for Sampling 27 9.6.1 Consumer Packs 27 9.6.2 Bulk Product 27 9.6.3 Mould Ripened Cheese 27 9.7 Environmental Samples 27 10.Environmental Testing 28 10.1 Introduction 28 10.2 Classification of Environmental Samples 28 10.3 Action Required for Positive Environmental Samples 28 11.Test Methods 30 11.1 Introduction 30 11.2 Reference Test Method 30 11.3 Alternative Test Methods-Rapid Kits 30 12.Cleaning and Sanitising 31 12.1 Introduction 31 12.2 Cleaning 32 12.2.1 Liquid Product Contact Surfaces 32 12.2.2 Dry Cleaning 32 12.2.3 Cleaning In Place(CIP)Systems 32 12.2.4 Manual Cleaning 33 12.3 Sanitation 33 12.4 Water Quality 33 12.5 Verification 34 References 35 Appendix 1 Address List for ADASC Members 36 Appendix 2 Definitions.37 Appendix 3 Procedure Following Listeria spp Contamination in Product 38 Appendix 4 Procedure Following Listeria monocytogenes Contamination in Product.39 Appendix 5 Example of a Routine Clearance Program.40 Appendix 6 Procedure for Listeria spp Environmental Sampling.41 Appendix 7 Explanatory Notes.44 ADASC LISTERIA REQUIREMENTS.DOC ADASC 1999 Page 3 of 46 Version 2-January 2000 Listeria Manual 1.Foreword The Australian Dairy Authorities Standards Committee(ADASC)members are responsible for developing and administering legislation and inspection procedures to ensure that dairy products are hygienically manufactured and do not present a health risk to the consuming public.The Australian Manual For Control Of Listeria In The Dairy Industry(Listeria Manual)has been developed in consultation with dairy companies and the State Dairy Authorities.This edition of the Listeria Manual was reviewed by a team of dairy company and authority representatives who have particular experience in the area of Listeria and its control in the dairy industry.ADASC has adopted the Listeria Manual for use in the Australian dairy industry.This edition of the Manual replaces in full the July 1996 edition.The Listeria Manual is distributed and maintained by the Victorian Dairy Industry Authority.Copies of the manual can be obtained from your State Dairy Authority or by contacting:Industry Operations Secretary Victorian Dairy Industry Authority PO Box 548 RICHMOND VIC 3121 Phone:[phone] Fax:[phone] Email:vdiavicdairy.vic.gov.au ADASC LISTERIA REQUIREMENTS.DOC ADASC 1999 Page 4 of 46 Version 2-January 2000 Listeria Manual 2.Purpose and Scope The Listeria Manual has been developed to assist the dairy industry in the control of Listeria spp in the dairy processing environment.The Listeria Manual sets out the procedures to be adopted for the monitoring of Listeria spp,as well as the activities to be followed if Listeria spp is detected in dairy products or the environment.The mandatory clearance procedures and procedures for disposal of contaminated product detailed in the Manual(white pages)apply to dairy products manufactured in all States and Territories in Australia.Formal approval to vary any aspect of these procedures is required.Applications for approval must be submitted to the ADASC member of the State in which the establishment is located.The addresses for the ADASC members of each State are listed in Appendix 1.The procedures described in this Manual for the prevention of Listeria spp contamination and for cleaning and sanitising are for guideline purposes only(yellow pages).They are suggestions offered to dairy companies to assist in the control of Listeria spp in the dairy processing environment.ADASC LISTERIA REQUIREMENTS.DOC ADASC 1999 Page 5 of 46 Version 2-January 2000 Listeria Manual 3.Summary of Company Responsibilities The company must:(a)notify the State Dairy Authority(SDA)Representative of all Listeria monocytogenes isolations from product immediately.This is to be followed by written confirmation within 7 days.It is strongly recommended that the company notify their State Dairy Authority when Listeria spp is isolated from product.This applies as soon as the genus is known even though the species is not yet identified.It is also strongly recommended that the SDA Representative is advised of Listeria monocytogenes isolations in environmental samples;(b)notify the Health Department,or other relevant authorities,according to state regulation;(c)segregate contaminated product from other non-contaminated product;(d)ensure that contaminated product is labelled accordingly and clearly identified;(e)have in place a product recall procedure,as the detection of Listeria monocytogenes in product may necessitate a product recall;and (f)obtain approval from the SDA Representative for the disposal or reprocessing of contaminated product.ADASC LISTERIA REQUIREMENTS.DOC ADASC 1999 Page 6 of 46 Version 2-January 2000 Listeria Manual 4.Background on Listeria 4.1 Introduction Listeria monocytogenes is a foodborne pathogen that is capable of causing foodborne illness called Listeriosis.It presents a hazard to particular groups of consumers such as:the elderly,new born,pregnant women and those whose resistance to infection is weakened(eg.those with HIV,leukaemia etc).Listeriosis has a mortality rate of about 30%.Listeria spp are commonly found in many environments including soil,dirt,water and can be carried by both domestic and wild animals.The Listeria bacterium is widespread throughout the environment and is thus a contaminant of raw foods.Some features of Listeria spp include:(a)small,Gram-positive rods;(b)non-sporeformers;(c)can produce cholera-like toxins;(d)aerobic,it can grow in the presence of oxygen and carbon dioxide and in the absence of oxygen;(e)psychrotrophic(grows between 3C and 45C);(f)hardy organisms(survive for months in moist soil,and can survive freezing);(g)do not survive pasteurisation at 72C for 15 seconds;(h)tolerate a wide pH range,pH 4.6-9.5;(i)can grow in up to 20%sodium chloride;(j)ubiquitous in nature,found in silage,sewage,vegetable matter,wild and domestic animals,birds,and raw milk.There are six known species of Listeria.These are:Listeria monocytogenes Listeria innocua Listeria ivanovii Listeria seeligeri Listeria welshimeri Listeria grayi L.monocytogenes can be pathogenic to humans.There is some concern that L.ivanovii may also be pathogenic to humans.None of the other species have been shown to be pathogenic to humans.ADASC LISTERIA REQUIREMENTS.DOC ADASC 1999 Page 7 of 46 Version 2-January 2000 Listeria Manual Its wide distribution and the ease with which it becomes established in food processing plants suggests that L.monocytogenes may have long been a common contaminant of our food supply.The relative rarity of foodborne Listeriosis and its severity in susceptible individuals may indicate either that very few are susceptible to it or that the infective dose,even in those at risk,is high.It has been suggested that this dose may be 100 to 1000 cells.L.monocytogenes is killed by the pasteurisation process and therefore it is most likely that the contamination of milk and dairy products would occur at the post pasteurisation stage.A most important property of L.monocytogenes is its ability to multiply slowly in foods at chill temperatures and most foods incriminated in Listeriosis have been held under refrigeration.Thus,any ready to eat food that is contaminated with Listeria monocytogenes which is held under refrigeration may eventually develop a population of these bacteria that is a danger to susceptible consumers.The risk of foodborne listeriosis to consumers other than those in susceptible groups listed above appears to be minimal.Many of us may carry Listeria spp in our intestinal tracts without any signs of illness.However susceptible consumers should avoid foods known to have caused the disease.These include soft cheese,pre-cooked meat and poultry products and prepared salads which have been refrigerated for long periods.Fresh vegetables may be contaminated with Listeria spp from soil and should be well washed and sanitised before being eaten raw by at-risk consumers.It must be stressed that L.monocytogenes is common in many foods,yet appears to pose a hazard only to particular groups of consumers.4.2 Significance in the Dairy Industry Extensive surveys have shown that Listeria is widely distributed in a variety of dairy products and is commonly found in dairy processing environments.Although there has not been a dairy related Listeriosis outbreak in Australia,Listeria has caused significant problems for the Australian dairy industry.The presence of Listeria in dairy products has lead to product recalls,destruction of contaminated product,short term plant closures and extensive clean up procedures.These incidents can cause substantial losses for the factories involved and can result in a loss of consumer confidence in the safety of dairy products.4.3 Prevalence of Listeria in the Dairy Industry 4.3.1 On Farm On the farm,the environmental conditions for the growth of Listeria is ideal.The organism can grow in soil,muddy and dusty conditions,in water and in dams.Cows can be carriers and mastitis can result from a Listeria infection.The feeding of poor quality silage is another problem area,as the organism can grow in poorly fermented silage.ADASC LISTERIA REQUIREMENTS.DOC ADASC 1999 Page 8 of 46 Version 2-January 2000 Listeria Manual 4.3.2 Factory Environments L.monocytogenes is quite well adapted to dairy factory environments.It is generally more common in the type of factory where conditions tend to be wet and cool with areas of pooled water or liquid.The organic load on the floors and in the drains if high can also contribute to the growth and survival of Listeria.Use of high pressure hoses can spread the organism by fine water sprays,known as aerosols,and dilute sanitisers in areas such as drains rendering them ineffective.Factories producing primarily liquid milk products have been found to have the highest incidence of Listeria spp-up to 59%.Despite the high incidence,most production in these areas are enclosed and thus the risk of Listeria contamination after pasteurisation is limited to a few critical steps such as pumping and filling/cartoning.4.3.3 Milk and Dairy Products Most dairy products are susceptible to Listeria spp contamination if hygiene is not good during manufacture.Listeria spp has been detected in Australia in a range of products which include:pate,cheese,ice cream,take-away foods,pre-cooked frozen foods and manufactured meat.While the incidence of detection of Listeria spp in dairy products in Australia is low,Listeria is capable of growing at refrigeration temperatures,and can be enhanced in the presence of another bacterial species called Pseudomonads which are naturally present in milks bacterial population.In most cases,contamination has been found to result from contact with an environmental source within the factory premises after the milk has undergone pasteurisation.Listeria has been isolated from many dairy products,including ice-cream and certain types of cheese.In soft ripened cheese contamination is limited to the first few millimetres under the rind or surface.Hard cheese such as parmesan do not favour growth,and other cheese such as colby,swiss,provolone,Munster,fetta and limbeger show gradual die-off of the bacteria.In mozzarella,the bacteria will survive the making process but not the stretching temperatures.Listeria monocytogenes will not grow in cottage cheese,but can survive.Listeria has also been isolated on a few occasions in yoghurt,as post processing contamination,but it will not survive in yoghurt with a pH 4.6.Dairy products most at risk are:processed milk,high moisture-low acid cheese,surface-ripened cheese,blue vein cheese,sliced,shredded and grated cheese,cream,ice cream and other products in refrigerated storage conditions.4.4 Occurrence of Listeria in Dairy Factory Environments Areas that have been identified as the major sources of the organism are those associated with transport of product,cooling and storage areas.Within these areas the most likely sources have been determined as transport into the factory,drains,floors,conveyors and crate wash lines.Work practices of factory personnel and the dispersal of the organisms in water sprays and droplets have also been identified as significant carriers of the organism throughout a factory.ADASC LISTERIA REQUIREMENTS.DOC ADASC 1999 Page 9 of 46 Version 2-January 2000 Listeria Manual 5.Listeria Prevention Procedures 5.1 Introduction Listeria spp can be carried by animals,birds and insects and may be found in soil,water,silage,dust and manure,any of which can lead to daily contamination of raw milk,bulk milk collection tankers and the boots and clothing worn by tanker drivers.The transfer of Listeria spp from the farm to the factory milk receival areas is therefore difficult to prevent.While total elimination of Listeria spp from raw products is an improbable task,its presence in processed food can be controlled.Spread of Listeria spp can be controlled at a farm,factory and distribution level,and there are steps that can be taken to minimise or prevent the organisms proceeding further into the factory.5.2 Steps to Control Listeria Entry to Plant Areas Specific aspects which require special attention for the control of Listeria spp are:(a)isolate the receival area and associated personnel from the processing and packaging areas.Rest