Microbial Interventions In Poultry Processing Worldwide: Successes and Opportunities North America European Union Australia Scott M. Russell, Ph.D. Professor Poultry Science Department The University of Georgia GA Poultry Conference 2010
Topics covered • Studies discussed • Reasons why we differ – Sampling differences – Intervention differences • The data obtained for the U.S., European Union, and Australia • Implications • Global importance
Studies conducted • Scientific Report of the European Food Safety Authority, 2010 – Analysis of the baseline survey on the prevalence of Campylobacter in broiler batches and of Campylobacter and Salmonella on broiler carcasses in the EU. Part A: Campylobacter and Salmonella prevalence estimates for 2008. EFSA Journal, Vol. 8(3):1503, Parma, Italy. • The United States Department of Agriculture, Food Safety Inspection Service, Office of Public Health Science, Microbiology Division – The Nationwide Microbiological Baseline Data Collection Program: Young Chicken Survey. July 2007 – July 2008 • Food Standards Australia New Zealand (FSANZ) – Coordinating agency for a baseline survey to obtain information on the likelihood of live chickens being contaminated on-farm with Salmonella and Campylobacter
Importance • These data serve to demonstrate the dramatic differences in approaches used around the world and how these approaches affect the safety of poultry products in these areas
Sampling Methods • North America: – Whole carcass rinse – 400 mL buffered peptone water • European Union: – 3 - 25 g neck skin samples from 3 different birds – Pool them – Mix with diluent and test – Cox et al. 2009 found that, on many carcasses, the neck skin method picked up the Salmonella , but none was found in the carcass rinse for that carcass and in other cases, the reverse occurred – Some countries in EU, China, Russia and other so called “ Salmonella negative” countries : – Burn breast skin with torch or sterilize with iodine – Use a sterile coring bit to drill deep into breast and collect sample • Never Salmonella positive!!!
Methods comparison Cox et al. (2009)
Methods comparison Cox et al. (2009)
Sampling Methods • At first glance, the methods seem to be similar in terms of sensitivity for the pre-IOBW samples • The neck skin method appears more sensitive on post-chill samples • However, upon closer inspection, different carcasses that were positive for Salmonella were detected using the two different methods
Intervention Differences
Breeders • U.S. approach – Some companies vaccinate for Salmonella – CE is not effective because undefined cultures are not allowed • European approach – Many countries use vaccination and/or competitive exclusion – Three (Denmark, Sweden, The Netherlands) test all breeder flocks for Salmonella • If a flock tests positive, it is slaughtered
Breeders • For European countries that kill all Salmonella positive breeders: • Still have 3 to 6% positive for Salmonella • These countries do not produce as many chickens a year as a small town in Georgia! – Sweden produces 72.1 million chickens/yr – Athens, GA produces 156 million chickens/yr • Thus, in the US, the size of the industry makes this approach completely impossible
Growout • U.S. approach – Some companies vaccinate for Salmonella – CE is not effective because undefined cultures are not allowed • European approach – Many countries use vaccination and/or competitive exclusion – In countries where they slaughter Salmonella positive flocks, the number of chickens in these flocks with Salmonella is very low
Growout • U.S. approach – We are allowed to use antibiotics for therapeutic purposes and as a growth promoting • European approach – Although some antibiotics are allowed to be used for therapeutic purposes, they use them sparingly and they have banned most growth promoting antibiotics
From: Casewell et al. (2003) “Following the ban of all food animal growth -promoting antibiotics by Sweden in 1986, the EU banned avoparcin in 1997 and bacitracin, spiramycin, tylosin, and Virginiamycin in 1999” “There has been an INCREASE in human infection from vancomycin resistant Enterococci in Europe” “The ban on growth promoting antibiotics has, however, revealed that these agents had IMPORTANT prophylactic activity and their withdrawal is now associated with a deterioration in animal health, including increased diarrhea, weight loss, and mortality” “A directly attributable effect of these infections is the increase in usage of therapeutic antibiotics in food animals….all of which are of direct importance in human medicine” “The theoretical and political benefit of the widespread ban of growth promoters needs to be more carefully weighed against the increasingly apparent adverse consequences”
Pickers • Rubber fingers in pickers: – Squeeze carcasses, making feces come out – Rub feces on skin around and cross- contaminate from carcass to carcass • Can significantly increase Salmonella prevalence and Campylobacter numbers • Campy is found in high numbers in the ceca, which is expressed during picking
The effect of picking – In the U.S: • Spreads pathogens and increases prevalence • This problem is eliminated by chemical intervention later on – In E.U. and Australia: • Spreads pathogens and increases prevalence • This problem is NOT corrected later on and the consumer suffers from it
Inside/outside bird washer and all other washers – In the U.S: – Post-pick washer, IOBW, final bird washer • Chlorine is often used • Organic acids may be used as processing aids • These chemicals prevent cross- contamination – In Europe: • No chemicals are allowed in the plant • Cross-contamination is unchecked
Online Reprocessing • Trisodium phosphate • Sanova (acidified sodium chlorite) • ClO 2 • HOCL (TomCo) • Parasafe (Inspexx 100) • Bromotize • FreshFx • Cecure (cetylpyridinium chloride)
Online Reprocessing • Can reduce pathogens significantly • Reduced Salmonella in one plant by 83%!! • Contact time is short (2 minutes) • Chemicals are very high tech, fast acting, powerful, and effective
Poultry Chiller Interventions
Almost all plants in the U.S. use immersion chillers
Immersion chilling as an Intervention • Research indicates: – Proper use of chlorine or peracetic acid is essential to reducing Salmonella – Most studies demonstrate that the chiller can cut Salmonella incidence by 50-70% if operating properly – Biggest hurdle available – Contact time
Almost all plants in the E.U. use air chillers
EU Air Chilling – Can allow cross- contamination as air moves rapidly over carcasses and transmits bacteria – No chemicals are used to eliminate pathogens
Canadian Air Chilling – Chemical dips are used prior to entry into the chiller – Prevents cross- contamination and lowers pathogens on carcasses
U.S. versus E.U.
Percentage of carcasses positive for Salmonella at rehang and post-chill in U.S. poultry plants Percentage of carcasses positive for Salmonella 45 40 35 30 25 20 15 10 5 0 Rehang (front end of plant) Post-Chill
Interpretation • The U.S. is doing an exceptional job using interventions that are able to reduce Salmonella prevalence by 35.5% during slaughter • Three important observations may be made here: • 1) The percentage of post-chill carcasses that are contaminated with Salmonella in the E. U. is 10.51% higher than in the U.S. • 2) Salmonella increases during slaughter in European slaughter facilities (the latest data indicate that live broilers are between 3 and 6% positive for Salmonella and goes up to 15.7% during processing, but decreases dramatically in U.S. slaughter facilities • 3) The variance in percentage of Salmonella positive carcasses is very low in facilities in the U.S. demonstrating that, in the U.S., processors are able to control these bacteria
Number of Salmonella cells/mL of carcass rinse on Salmonella positive broiler carcasses at rehang and post- chill in U.S. poultry plants Average number of Salmonella /mL of rinse 3.5 3 2.5 2 1.5 1 0.5 0 Rehang (front end of plant) Post-Chill
Interpretation • U.S. processing facilities, the plants are doing an exceptional job controlling the number of Salmonella cells per carcass • The number of cells on post-chill carcasses is very low with a range of 0.11 to 0.18 cells/carcass • The variance is insignificant and indicates a high level of control • This well below an infective dose of Salmonella • Because of chemical interventions , Salmonella cells are injured and unlikely to repair themselves during storage
Percentage of Campylobacter positive broiler chickens coming into the plant and exiting the chiller in the European Union 100.00% 90.00% Percentage of Positives 80.00% 70.00% 60.00% 50.00% 40.00% 30.00% 20.00% 10.00% 0.00% Incoming birds Post-chill carcasses
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