Salmonella and Other Pathogens of Importance in Beef Processing

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1 Salmonella and Other Pathogens of Importance in Beef Processing Mindy Brashears, PhD Director-International Center for Food Industry Excellence Department of Animal and Food Sciences Texas Tech University

2 History Discovered in19 th Century Typhoid Fever in Humans First Quarter of 20 th Century Lignieres coined the term Salmonella Kauffmann-White Scheme 2300 serovars

3 Characteristics of Salmonella Gram Negative, Non-spore-forming rod Very Adaptive Survives at wide ranges of temperature, ph, moisture levels Survival Can survive long periods of time in the environment

4 Salmonella Two Species S. enterica FOOD BORNE PATHOGENS S. Bongori (B IS capitalized) Serovars in 5 Subspecies of S. enterica 70% of isolates from human cases 61% of the isolates fall into 5 serotypes Typhymurium (23%), Enteritidis (21%), Heidelburg (8%), Newport (5%), Hadar (4%)

5 Reservoirs and Human Disease Typhimurium Associated with the most animal reservoirs Chicken, cattle, pigs 14% of total isolates from beef carcasses 10% of total isolates from chicken carcasses 18% of isolates from raw ground pork 15% of isolates from raw ground beef

6 Reservoirs and Human Disease Enteritidis Not frequently isolated from meat or meat products Traced to foods containing undercooked eggs Heidelberg Poultry 26% of total isolates from chicken carcasses 14% from turkey carcasses 30% from ground raw chicken 6% from raw ground pork

7 Reservoirs and Human Disease Newport Beef Consumption 2% of total isolates from raw ground beef Hadar Turkey Consumption 15% of total isolates from turkey carcasses 24% from raw turkey

8 Horizontal Transmission Salmonella shed from livestock and domestic fowl are largely responsible for persistence of Salmonella in environment Stress during transport accelerate the spread of the pathogen from the fecal-oral route Prevalence generally increases before slaughter

9 Vertical Transmission Adult to Offspring Cattle Salmonella persists in the udders of cows for up to 2.5 years resulting in vertical transmission through the milk Poultry Eggs are contaminated via the trans-ovarian route

10 Three Groups Humans only S. Typhi, S. Paratyphi A and C Host-Adapted Serovars S. Gallinarum (Poultry), S. Dublin (cattle) Unadapted Food-borne Pathogens

11 Reservoirs Poultry and Poultry Products Meat Beef and Swine Fish Most commonly found pathogen in meat products Based on USDA Testing Fruits and Vegetables

12 Distribution Primary Reservoir Intestinal Tract of Animals Many Other Reservoirs Water Other Body Organs Carriers Animal Feeds Food Products

13 Salmonella and Food-borne Disease Leading cause of FBI in US from % of all outbreaks 1.4 million illnesses annually Single most common cause of death 550 fatal cases/year Estimated cost $0.5 billion to $2.3 billion

14 Recent Outbreaks and Recalls Leading Cause of DEATH Often Leading Cause of Food-Borne Illness Recent Outbreaks Eggs Mayonnaise Cheese Animal Products Ice Cream Breakfast Cereal Peanut Butter Fruit and Vegetables

15 Regulatory Status FDA and USDA Zero Tolerance in Ready to Eat Foods only Carcasses USDA Baseline Established Carcasses and Ground USDA Guidelines Salmonella Testing of Carcasses and Ground Beef Up to 3 sets taken, failure might result in regulatory action

16 Salmonella Cycle Man Environment Food and Feed Animal

17 Disease Syndrome Several Clinical Conditions Typhoid Fever Enterocolitis (Food-borne) 8-72 hour incubation Non-bloody diarrhea Abdominal pain Supportive Therapy and Electrolyte replacement is usually all that is needed Systemic Infections Infectious Dose High (Relative to E. coli O157:H7)

18 Salmonella in Cattle

19 Incidence of Salmonella in Beef Cattle and Feedlots in the US

20 Quarterly Incidence of Salmonella in Beef Feedlot Cattle in 1999 in the US

21 Incidence of Salmonella in Dairy Calves in the US in 1992

22 Other Pathogens of Concern in Fresh Beef Processing Listeria monocytogenes Largest concern is in Ready to Eat Meats Fresh product and Contaminate Ready to Eat Environments Campylobacter Often the #1 cause of bacterial food-borne illness Commonly found on fresh beef products Mild Illness Control measures for E. coli and Salmonella should control LM and Campy

23 International Center for Food Industry Excellence