Microbial Interventions In Poultry Processing Worldwide: Successes and Opportunities North America European Union Australia GA Poultry Conference 2010 Scott M. Russell, Ph.D. Professor Poultry Science Department The University of Georgia
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)
Cox et al. (2009) Methods comparison
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
U.S. approach Growout 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 crosscontaminate 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 crosscontamination 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 crosscontamination 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 crosscontamination and lowers pathogens on carcasses
U.S. versus E.U.
Percentage of carcasses positive for Salmonella Percentage of carcasses positive for Salmonella at rehang and post-chill in U.S. poultry plants 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
Average number of Salmonella/mL of rinse Number of Salmonella cells/ml of carcass rinse on Salmonella positive broiler carcasses at rehang and postchill in U.S. poultry plants 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 Positives Percentage of Campylobacter positive broiler chickens coming into the plant and exiting the chiller in the European Union 100.00% 90.00% 80.00% 70.00% 60.00% 50.00% 40.00% 30.00% 20.00% 10.00% 0.00% Incoming birds Post-chill carcasses
Interpretation Campylobacter prevalence in European Union plants increases during processing This is easy to understand because no chemical interventions are used to eliminate Campylobacter during processing Thus, any intestinal tearing during evisceration, cross-contamination during scalding or picking, and any common points of contact where Campylobacter may come off of a positive carcass and be spread to subsequent negative carcasses all represent ways that Campylobacter may increase in these plants Because no chemicals are used during processing, it is impossible for the slaughter plants to have any beneficial impact on Campylobacter on the final product The second point of interest is the enormous variability in the percentage of carcasses positive for Campylobacter over the different countries in the E.U. The variance is between 2 and 100% positive for incoming birds and 4.6 to 100% for finished post-chill carcasses This high variance means that there is very little control over these bacterial populations and the values likely reflect the levels coming into the plant and cross-contamination, as opposed to any positive benefits the slaughter facility may be having
Percentage of carcasses positive for Campylobacter Percentage of carcasses positive for Campylobacter at rehang and post-chill in U.S. poultry plants 80 70 60 50 40 30 20 10 0 Rehang (front end of plant) Post-Chill
Interpretation Chemical intervention in U.S. plants are able to reduce Campylobacter prevalence by 60% during slaughter Three important observations may be made here: 1) The percentage of post-chill carcasses that are contaminated with Campylobacter in the E. U. is 65% higher than in the U.S. 2) Campylobacter increases during slaughter in European slaughter facilities, but decreases dramatically in U.S. slaughter facilities 3) The variance in percentage of Campylobacter positive carcasses is much higher in European facilities, demonstrating a lack of control
Average number of Campylobacter/mL of rinse Number of Campylobacter cells/ml of carcass rinse on Campylobacter positive broiler carcasses at rehang and post-chill in U.S. poultry plants 10000 9000 8000 7000 6000 5000 4000 3000 2000 1000 0 Rehang (front end of plant) Post-Chill
Interpretation In the U.S. processing facilities, the plants are doing an exceptional job controlling Campylobacter and the number of cells on post-chill carcasses is very low with a range of 7.5 to 11.9 cells/carcass This is exceptional because Campylobacter on incoming birds is usually 100 s to 1,000 s of cells/ml of rinse initially The variance from carcass to carcass is insignificant and indicates a high level of control
Percentage of Positives Percentage of Salmonella positive broiler carcasses exiting the chiller in the U.S. and European Union 20.00% 18.00% 16.00% 14.00% 12.00% 10.00% 8.00% 6.00% 4.00% 2.00% 0.00% Post-chill U.S. Post-chill E.U.
Percentage of Positives Percentage of Campylobacter positive broiler carcasses exiting the chiller in the U.S. and European Union 100.00% 90.00% 80.00% 70.00% 60.00% 50.00% 40.00% 30.00% 20.00% 10.00% 0.00% Post-chill U.S. Post-chill E.U.
Interpretation There is no question that the U.S. is doing a superior job in controlling Campylobacter and Salmonella on processed broiler chicken carcasses The difference between the approaches used by the U.S. and Canada and the E.U. is evident because 65.14% fewer carcasses exiting the chiller in the U.S. are contaminated with Campylobacter Likewise 10.51% fewer carcasses exiting the chiller in the U.S. are contaminated with Salmonella These reports indicate that the poultry industry in the U.S. and Canada are able to control both Campylobacter and Salmonella in a holistic sense when compared to the processors in Europe
U.S. versus Australia
Percentage of carcasses positive for Campylobacter Percentage of carcasses positive for Campylobacter at the farm, pre-slaughter and post-chill in Australian poultry plants 90 80 70 60 50 40 30 20 10 0 On Farm Pre-Slaughter Post-Chill
Interpretation The most important observation is that Campylobacter prevalence in Australian plants increases during processing Intestinal tearing during evisceration, crosscontamination during scalding or picking, and any common points of contact where Campylobacter may come off of a positive carcass and be spread to subsequent negative carcasses all represent ways that Campylobacter may increase in these plants Without significant chemical intervention, this is not surprising
Percentage of Positives for Salmonella Percentage of carcasses positive for Salmonella at the farm, pre-slaughter and post-chill in Australian poultry plants 50.00 40.00 30.00 20.00 10.00 0.00 On Farm Pre-Slaughter Post-Chill
Interpretation It is interesting that Salmonella cycles in the flock and is high during growout In the last week or two before slaughter, the levels of Salmonella begin to decrease This is why the level pre-slaughter was low During slaughter, the level of Salmonella increases dramatically in Australian plants due to cross-contamination Chemical intervention is absolutely necessary to prevent this from occurring
Percentage of carcasses positive for Salmomella Percentage of Salmonella positive broiler carcasses exiting the chiller in the U.S., European Union, Australia 40.00 35.00 30.00 25.00 20.00 15.00 10.00 5.00 0.00 Post-chill U.S. Post-chill E.U. Post-chill Australia
Serious Problem Because the European model targets a specific pathogen (Salmonella) and efforts are made the in field to eliminate it, these efforts have NO impact on Campylobacter Vaccines for Salmonella, competitive exclusion cultures designed to control Salmonella will have NO effect on Campylobacter This means that this enormous cost associated with efforts to control Salmonella will have to be doubled and adjusted for Campylobacter This will likely be unsuccessful as the science behind controlling Campylobacter during breeding and growout is very limited
How do these approaches affect human food-borne illness? Sweden
Why do Europeans and Australians refuse to change their approach? Misunderstanding about perceived versus real danger Far more afraid of chemical contamination of food and its impact than bacterial contamination In reality, problems with chemical adulteration and/or toxicity are almost immeasurable (nonexistent) Problems with food-borne illness in Europe are enormous They simply refuse to look at reality The strong emotions evoked by the idea of chemicals in food affects their decision making in a disproportionate way Billion dollar corporations in the U.S. have traveled to Europe with reams and reams of toxicity data to try to get the EU commission to allow the use of their chemistry only to have them say NO
Conclusions: Global Importance These profound differences in the way we sample poultry products and use interventions during growout and processing have the following impact: Trade barriers (U.S. cannot ship to Europe or Russia right now and China is throwing up a barrier as well) Lead to seriously false claims (China, Russia, France claim Salmonella free poultry) Misperceptions among consumers lead to differences in price and preference which are based on misinformation Much higher rates of food-borne illness in E.U. and Australia from Salmonella, but seriously high rates of Campylobacter infection