Case studies in food microbiology for food safety and quality /

Table Of Contents:

A. Developing Strategies for Control

Water as a Vector of Organisms 3(23)

Key issues

Water

Vibrio cholerae

Microbial survival and growth in water

Food safety control, and the need for national infrastructure

The Case Study: Cholera in Portugal, 1974 3(4)

Background to the outbreak 4(2)

The investigation in Tavira and Faro, Southern Portugal 6(1)

The investigation of the bottled water 6(1)

The case study source materials 7(1)

Background 7(11)

Potable water 7(2)

Bottled water 9(5)

Ice and drinking ice 14(3)

Surveillance 17(1)

Exercises 18(1)

Exercise 1. What were the factors which caused the cholera outbreak?

Exercise 2. What prevented previous and future outbreaks?

Commentary 19(4)

Summary 23(1)

References 24(2)

Expectations of Food Control Systems
in the Past, and Now 26(30)

Key issues

Meat
bottled wild duck paste

Clostridium botulinum

Sources of pathogens

Food poisoning outbreak
identifying its cause

Microbial growth conditions

Toxin production in food

Control of food safety in manufacture: then and now

The Case Study: Wild Duck Paste, 1922 26(9)

How it happened 26(5)

The bacteriology 31(2)

The public enquiry 33(2)

Background 35(7)

The organism: Clostridium botulinum and botulism 35(4)

Meat pastes 39(3)

Exercises 42(2)

Exercise 1. How was the outbreak of food poisoning investigated?

Exercise 2. How are outbreaks of food poisoning investigated today?

Exercise 3. How might the contamination of the meat paste have occurred?

Exercise 4. What is required today for the safe processing and handling of such a product?

Commentary 44(9)

Summary 53(2)

References 55(1)

Zoonotic disease 56(26)

Key issues

Milk: a primary source of pathogens

Pasteurised milk and salted telemea cheese

Mycobacterium bovis

Zoonotic diseases; tuberculosis

The effect of political change on control efficiency

The Case Study: Milk Safety Problem in Romania 56(4)

Milk and its problems pre- and post-1990 56(4)

Background Information on the Experience and Management of TB in Milking Cows and in Milk in the UK: 1930 to Present Day 60(9)

Tuberculosis and the tuberculosis organism 60(2)

Transmission of TB and other infections by milk 62(6)

Milk and the incidence of TB in cattle in the UK in the 1990s 68(1)

Exercises and Study Objectives 69(1)

Exercise 1. Is obligatory pasteurisation enough to control milk-borne tuberculosis?

Exercise 2. Why does change put an existing control system at risk?

Commentary 70(7)

Summary 77(2)

References 79(3)

Should Pasteurisation of Drinking Milk Be Obligatory? 82(17)

Key issues

Drinking milk

Campylobacter jejuni

Developing strategies for control

The need for a holistic approach to control

The Case Studies: Campylobacter Jejuni, Outbreaks Associated With Raw and Pasteurised Milks 82(2)

The jogging rally 82(1)

The boys' school 83(1)

The day nursery 83(1)

Background 84(3)

Campylobacter jejuni and the thermophilic campylobacters 84(2)

Milk and outbreaks of infectious intestinal disease 86(1)

Exercise 87(3)

Exercise. Should pasteurisation of milk be obligatory?

Commentary 90(4)

The three Campylobacter jejuni outbreaks 90(1)

Should pasteurisation of drinking milk be obligatory to protect public health? 91(3)

Summary 94(1)

References 94(5)

B. Techniques for Control

Surveillance and Microbiological Analyses 99(28)

Key issues

Meat: grilled kebabs

Meat: a primary source of pathogens

Salmonella and other organisms

Microbiological surveillance as an aid to control

Microbiological analysis as a tool

Hygiene

The Case Studies: Doner Kebabs, UK, 1992--1995 99(10)

An outbreak of Salmonella mikawasima associated with doner kebabs 99(3)

A small local survey in London, January to May 1994 102(4)

A national survey of the microbiological quality of doner kebabs, 1995 106(3)

Background 109(6)

Microbiology of raw meats 110(4)

The control framework for the sale and consumption of cooked kebab meat 114(1)

Exercises 115(2)

Exercise 1. What is achieved by sampling retail foods?

Exercise 2. What is required to produce reliable microbiological data?

Exercise 3. Does grilling produce safe meat?

Exercise 4. What contribution to public health does microbiological surveillance make?

Commentary 117(7)

Summary 124(1)

References 125(2)

Microbial Hazards 127(23)

Key issues

Fish
caviar and fish roes

Microbial hazards
spoilage organisms and pathogens

Fish: a primary source of organisms

Points of safety and quality loss

Microbial hazards
what are they?

Controls for microbial hazards

Hazard analysis

The Case Study: The Illegal Caviar Industry in the Late 20th Century 127(5)

Sturgeon and caviar 127(1)

The historical development of the caviar trade and the caviar industry 128(4)

Background 132(4)

Production and processing 132(2)

Pasteurization of caviar 134(1)

Potential for microbiological problems 134(2)

Exercises 136(2)

Exercise 1. Examining general and specific microbiological hazards relating to the quality and safety of caviar

Exercise 2. Ensuring that re-packed caviar is of optimal quality and safety

Exercise 3. Preventing the import of unsafe caviar

Exercise 4. Is black market caviar of good microbiological quality?

Commentary 138(9)

Summary 147(1)

References 148(2)

Post-production Product Handling and Acceptability 150(24)

Key issues

Vegetables and fruit; canned tomato paste
a high acid food

Spoilage organisms and Clostridium botulinum

Canning

Microbial death and commercial sterility

Microbial growth conditions

Control of food safety and quality during manufacture, and after

Product acceptability

The Case Study: The Quality of Tomato Paste Available in Nigeria 150(6)

Consider the following correspondence 150(2)

What then happened 152(4)

Background 156(6)

Exercises 162(2)

Exercise 1. Taking a forensic view of microbiological data

Exercise 2. When is a product spoiled?

Exercise 3. How can the microflora of a product be used to determine whether it should be imported?

Exercise 4. When is the consumers point of view taken into account?

Commentary 164(8)

General principles 164(5)

Exercises 169(2)

Additional information 171(1)

Summary 172(1)

References 173(1)

HACCP and the Responsibilities of the Food Producer 174(33)

Key issues

Shell eggs and chocolate mousse

Salmonella spp.

Cross contamination

HACCP

The Case Studies: Raw Eggs and Chilled Chocolate Mousse Dessert 174(4)

Chef must serve time after wedding treat turned sour 174(1)

D-Day veterans protected from dangers of soft eggs 175(1)

The chocolate mousse outbreak 176(2)

Background 178(12)

Salmonella spp. and salmonellosis 178(1)

Salmonella spp. and infection of eggs 179(4)

Salmonella spp.
its growth, survival and death 183(7)

Exercises 190(2)

Exercise 1. Investigating the cause of the food poisoning outbreak

Exercise 2. The microbiological safety of lightly cooked desserts

Exercise 3. How HACCP can help manage safety

Exercise 4. Examining the responsibility of a food producer in the use of raw ingredients

Commentary 192(13)

Summary 205(1)

References 205(2)

Product Formulation and Control 207(28)

Key issues

Yoghurt

Clostridium botulinum

The `combined treatment' approach to control

HACCP

The Case Study: Botulism and Hazelnut Yoghurt, 1989 207(5)

Background 212(6)

Fruit purees and their preservation 212(4)

Nuts and their preservation 216(1)

Yoghurt and its manufacture 216(2)

Exercises 218(1)

Exercise 1. Examining the strategy of using combined treatments for microbial control

Exercise 2. Managing the safety and quality of fruit yoghurt

Commentary 219(8)

Summary 227(4)

References 231(4)

C. Risk

Views of Risk 235(23)

Semi-soft cheeses, and raw milk

Escherichia coli O157:H7

Cross contamination

Control of Escherichia coli O157:H7 in cheesemaking

HACCP

Risk perception

The Case Study: Raw Milk Cheese and its Safety 235(3)

The outbreak, and public health protection measures 235(1)

The Appeal
evidence from the Department of Health 236(1)

The Producer and Affineur's perspective 237(1)

The cheese 238(1)

Background 238(8)

Raw milk quality 241(1)

Cheese making 241(3)

Escherichia coli O157:H7 in cheeses 244(2)

Exercises 246(1)

Exercise 1. Cheese safety and HACCP

Exercise 2. Defending the production of raw milk cheese

Exercise 3. Views of risk: sampling and predicting the safety of batches of cheeses

Commentary 246(10)

Summary 256(1)

References 256(2)

Hazards and risks 258(49)

Key issues

Cheese
blue cheese

Listeria monocytogenes

Virulence and pathogenicity: when is an organism a food hazard?

Risk to public health and food safety policy

Microbiological tests and their meaning

Risk management

The Case Study: Listeria Monocytogenes and Lanark Blue Cheese, Scotland 1995 258(10)

The newspaper case 258(1)

The chronology 259(8)

The hearing before the Sheriff in the Sheriff Court in Lanark 267(1)

The judgement 268(1)

Background to the Technical Arguments Put in the Hearing, August 1995 268(17)

Lanark Blue Cheese 270(1)

Listeria and Listeria monocytogenes 270(15)

Exercises 285(1)

Exercise 1. Evaluating the microbiological test data by which Listeria monocytogenes was reportedly found at unacceptable level in the cheese

Exercise 2. Considering the 1995 policy by which public health was to be protected from Listeria monocytogenes

Exercise 3. Following the court hearing, what options were open to the cheese producer?

Exercise 4. Considering how policy has changed since 1995

Commentary 286(17)

Summary 303(1)

References 303(4)

The Need for Food Hygiene 307(26)

Key issues

Cooked meat pies

Escherichia coli O157:H7

Infection and cross contamination in the food chain

Food hygiene training and management

The Case Study: Cooked Meat Products, Central Scotland, November and December 1996 307(9)

The John Barr case and the Pennington Group report 308(3)

Criminal proceedings against Mr. J. Barr 311(1)

John Barr and Sons fined for food hygiene offences 312(1)

The Fatal Accident Enquiry chaired by Sir Graham Cox, reported 20 August 1998 312(4)

Background Information 316(9)

Recommendations from the Pennington Group Report, 1997 316(4)

E. coli and E. coli O157:H7 320(2)

Legislative background to meat hygiene 322(3)

Exercises 325(1)

Exercise 1. Determining how E. coli O157:H7 could have been present in cooked foods

Exercise 2. Identifying reasonable precautions which would prevent E. coli O157:H7 entering the food chain

Exercise 3. Considering the hygiene training requirements and the implementation of good hygiene practice

Commentary 326(5)

Summary 331(1)

References 332(1)

A Shelf Life Problem 333(10)

Key issues

Chilled desserts and bottled vegetables

Psychrotrophic hazards and spoilage organisms

Perception of risk

Shelf life
safety and quality

The Case Studies and Background: Processed Vegetables and Chilled Desserts 333(1)

The shelf life of bottled vegetables under ambient storage 333(1)

The shelf life of chilled chocolate dessert 334(1)

Exercise 334(1)

Exercise. Determinants of shelf life and perception of risk

Commentary 335(6)

References 341(2)

Airline Food and Control Failure 343(14)

Key issues

Cook--chill foods and airline foods

Staphylococcus aureus

Global dissemination of pathogens by air travel

Risk factors and high and low risk foods

HACCP

The Case Study: Food Poisoning Outbreak Aboard an Intercontinental Flight 343(3)

Background 346(2)

Exercises 348(1)

Exercise 1. The conditions which permit a food pathogen
Staphylococcus aureus
to grow

Exercise 2. The risk factors threatening the safety of airline foods

Exercise 3. Management strategies to produce safe airline foods

Commentary 349(5)

References 354(3)

D. Sampling, Criteria and Acceptance

Global Dissemination of Organisms and Their Control 357(17)

Key issues

Fish meal and animal feeds; low aw materials

Globalisation of food supply and the spread of pathogens

Salmonella spp.

Contamination and cross contamination

Microbial survival and significance

Import acceptance
sampling criteria

The Case Studies 357(5)

The Paragould outbreak of Salmonella agona 357(1)

Salmonella agona in the UK 358(1)

Salmonella agona in peanut snack foods 358(4)

Background 362(5)

Animal feeds in the 1970s and 1980s 362(3)

The survival of Salmonella in low water activity foods and feeds 365(2)

Exercises 367(1)

Exercise 1. How does fish meal become and remain contaminated with Salmonella?

Exercise 2. Are the case studies connected to globalisation in the food supply chain?

Exercise 3. Sampling and determination of contamination in bulk supplies

Commentary 368(4)

Summary 372(1)

References 372(2)

Extending Shelf Life
Compromising Safety? 374(11)

Key issues

Raw fish and sushi

Vibrio parahaemolyticus

Shelf life

HACCP in seafood management

Microbiological criteria

The Case Study: Extending the Shelf Life of Raw Sea-Foods in Australia 374(1)

Background 375(2)

Vibrio parahaemolyticus

Exercises 377(1)

Exercise 1. Would extending the shelf life of raw fish cause a rise in the number of cases of Vibrio parahaemolyticus?

Exercise 2. What are the necessary controls for the safety of sushi?

Exercise 3. Could setting criteria for Enterobacteria help manage the risk of Vibrio parahaemolyticus in seafoods which are eaten raw?

Commentary 378(5)

References 383(2)

Acceptable, Unsatisfactory and Unacceptable Concentrations of Pathogens in Ready-to-eat Food 385(14)

Key issues

Meat pate

Clostridium perfringens

Food poisoning risk factors

Developing microbiological criteria

Microbiological quality guidelines

The Case Study: C. Perfringens in Belgian Pates, 2000--2001 385(1)

Outline 385(1)

Background 386(3)

Some recipes for pates 386(1)

Sodium nitrite as preservative 387(1)

C. perfringens and food poisoning 388(1)

Exercise 389(3)

Exercise. Considering the concept of `acceptable microbial load'

Commentary 392(4)

Summary 396(1)

References 396(3)

E. Managing Risk

Managing Risk 399(4)

Key issues

Sandwiches

Food poisoning organisms

Factors affecting shelf life

Risk ranking, and risk management

HACCP training

The Case Study: Should Sandwiches Sold in a Hospital Cafe be Made by Volunteers? 399(1)

Exercise 400(1)

Exercise. Which method of sandwich production carries lower risk?

Background and Commentary 401(1)

References 402(1)

Changing a Risk Management Strategy 403(7)

Key issues

Raw fruit and vegetable salads

Shigella spp.

Risk management

The Case Study: Shigella Flexneri in Fruit Salads 403(1)

Background 404(2)

Shigella and food-borne disease 404(2)

Salads and food-borne disease 406(1)

Exercise 406(1)

Exercise. Does an outbreak of food borne disease found to be associated with a food provide reason to change existing practice?

Commentary 407(2)

References 409(1)

Hygiene Improvement at Source 410(19)

Key issues

Raw meat in the abattoir

Microbial load and enteric pathogens

E. coli O157:H7

Hygiene

Risk based scoring system for hygiene improvement

Risk management

The Case Study: Assessing and Scoring Hygiene During the Slaughter and Preparation of Red Meat 410(8)

Circular from MAFF 410(6)

Monthly reports from Meat Hygiene Service 416(1)

Press release from Meat Hygiene Service 416(2)

Enforcements results: Banded HAS scores 418(1)

Background 418(4)

Exercise 422(1)

Exercise. Understanding and comparing the old and new hygiene assessment systems (HAS)

Commentary 423(5)

Summary 428(1)

References 428(1)

What is Safe Food? 429(18)

Key issues

Milk, rice and other foods

Bacillus cereus

Risk analysis: assessing and managing risk

Safe food

The Case Study: Risk Associated With Pasteurised Milk, Residual Bacillus Spp. Spore Populations and Their Effects 429(4)

Background 433(3)

Bacillus food poisoning statistics, and two outbreaks of Bacillus cereus food poisoning 433(2)

Foods associated with Bacillus spp. 435(1)

Exercises 436(1)

Exercise 1. Assessing whether risk need increase when the shelf life of pasteurised milk is extended

Exercise 2. Identifying what safe food is

Commentary 437(6)

Risk analysis 437(2)

Guidance on assessing and managing risk associated with 7 day and 14 day shelf life milk 439(4)

Safe food 443(1)

Summary 443(1)

References 444(3)
Subject Index 447