A couple of days ago, I came across a reference to a report that claimed 85% of raw chicken delivered to the University Hospital in Geneva tested positive for strains of Escherichia coli resistant to extended-spectrum beta lactam antibiotics. These antibiotics belong to the penicillin family. The original study was published in Infection Control and Hospital Epidemiology, the journal of the Society for Healthcare Epidemiology of America. (Unfortunately, when I tried it, the link was broken).
Apparently, there were workers in the hospital kitchen who tested positive to carriage of the ESBL E. coli, however, the frequency was no greater than in the general population.
The finding of the high rate of contamination with ESBL resistant bacteria in the raw chickens is a concern, not because patients were at risk, but because it indicates that the poultry flocks had probably been exposed to antibiotics that are still used in therapy. Proper procedures in the kitchens should ensure that the contaminating bacteria are destroyed and that cross contamination from raw meat to cooked or fresh foods is controlled.
The use of antibiotics in animal husbandry is leading to increased incidence of antibiotic resistant bacteria. See my previous posts on antibiotics: http://foodsafetywithjaybee.blogspot.co.nz/2011/11/time-to-ban-antibiotic-use-in-animal.html
et seq.
When I gave my inaugural lecture as Professor of Food Microbiology, I reviewed the developments in microbiology that led to the discovery and development of penicillin. Before the advent of this antibiotic, a simple scratch with a rose thorn could be a death sentence if the scratch became infected. It would be a catastrophe if we returned to those days because we had squandered our slim advantage over the pathogenic bacteria for short term financial gains by the animal rearing industries.
Showing posts with label poultry. Show all posts
Showing posts with label poultry. Show all posts
Wednesday, March 12, 2014
Saturday, April 30, 2011
Walls have ears and bacteria have antibiotic resistance
Recently, I was having my lunch at a conference and couldn't help overhearing a conversation between two people sitting alonside me. I suppose I should have tried not to listen, but their discussion was in my own field.
It appeared that one of them had read a survey conducted on the bacteria isolated from poultry in USA. Even "organically grown" chicken contained bacteria that displayed multiple-antibiotic resistance. This implies that the chicken farms may be using antibiotics in the flock rearing operation, though it doesn't necessarily prove the point.
Without getting into the rights and wrongs of using antibiotics in rearing of "organically grown" poultry, this does point to a wider concern: that farmers may be using sub-therapeutic levels of antibiotics widely to improve growth rates and yields of all meat animals. Any bacteria that survive and grow in the presence of antibiotic are likely to be resistant to the chemicals and if these bacteria should go on to infect humans, those antibiotics will be useless for treatment.
I'm not sure if these people were talking about a survey*** conducted by the Translational Genomics Research Institute (TGen) in Arizona. These scientists tested 136 samples of 80 brands of beef, chicken, pork and turkey collected from 26 retail stores in five US cities. They found that nearly half of the samples contained Staphylococcus aureus and that just over half of these isolates were resistant to at least three classes of antibiotics. Further analysis suggested that the bacteria were from the animals and not from the processing factories, again indicating that antibiotics had probably been used in rearing the animals.
It might make meat more expensive, but I believe that governments must force the reduction in the amount of antibiotics used in animal rearing if we are to avoid catastrophic consequences for the human population in the near future. Remember: it has been estimated that the cost of getting a new drug onto the market is now between 2 and 3 billion dollars. We aren't going to get many new drugs at that rate.
*** The full report is available at:
(The report is a technical report, intended to be read by other scientists, but anyone should be able to follow the discussion).
It appeared that one of them had read a survey conducted on the bacteria isolated from poultry in USA. Even "organically grown" chicken contained bacteria that displayed multiple-antibiotic resistance. This implies that the chicken farms may be using antibiotics in the flock rearing operation, though it doesn't necessarily prove the point.
Without getting into the rights and wrongs of using antibiotics in rearing of "organically grown" poultry, this does point to a wider concern: that farmers may be using sub-therapeutic levels of antibiotics widely to improve growth rates and yields of all meat animals. Any bacteria that survive and grow in the presence of antibiotic are likely to be resistant to the chemicals and if these bacteria should go on to infect humans, those antibiotics will be useless for treatment.
I'm not sure if these people were talking about a survey*** conducted by the Translational Genomics Research Institute (TGen) in Arizona. These scientists tested 136 samples of 80 brands of beef, chicken, pork and turkey collected from 26 retail stores in five US cities. They found that nearly half of the samples contained Staphylococcus aureus and that just over half of these isolates were resistant to at least three classes of antibiotics. Further analysis suggested that the bacteria were from the animals and not from the processing factories, again indicating that antibiotics had probably been used in rearing the animals.
It might make meat more expensive, but I believe that governments must force the reduction in the amount of antibiotics used in animal rearing if we are to avoid catastrophic consequences for the human population in the near future. Remember: it has been estimated that the cost of getting a new drug onto the market is now between 2 and 3 billion dollars. We aren't going to get many new drugs at that rate.
*** The full report is available at:
http://dx.doi.org/10.1093/cid/cir181
(The report is a technical report, intended to be read by other scientists, but anyone should be able to follow the discussion).
Monday, April 21, 2008
What interests you most?
My Sitemeter collects statistics on usage of this blog (don’t worry, you can’t be identified) including pages visited and referrals from search engines like Google and Yahoo.
I looked through some recent stats and found that the most common questions referred to the safety of chicken (by far the most frequent referral), unpasteurized milk, coliforms and how bacteria can get into food. There were one or two surprising enquiries, but I won’t go into those.
Over the next few posts I’ll visit some of the more popular questions, starting with a report from New Zealand on campylobacteriosis and poultry.
The March 2008 Monthly Surveillance Report from ESR makes for interesting reading. http://www.surv.esr.cri.nz/surveillance/monthly_surveillance.php?
we_objectID=1548
The incidence of campylobacteriosis in the human population of New Zealand has fallen again. 450 campylobacteriosis cases were notified in March 2008 compared with 1145 cases notified in the same month of the previous year. The current 12 month rate* is 234 cases per 100,000 head of population, compared with 386 for the previous 12 months to March 2007 – a 39% reduction. Compared with the rates of other infectious diseases surveyed, this is a very significant achievement.
Though there is currently no direct evidence, at least some of this reduction must be because of the strenuous efforts made by the poultry industry to reduce the levels of contamination on fresh poultry and poultry products.
The Campylobacter surveillance data contain other interesting observations on the possible source of infection: of the cases where the information was recorded, 51% had eaten food from a food premise (I assume that means a restaurant or take-away); 38% had contact with farm animals; 22% had contact with other people showing symptoms of campylobacteriosis. Other possible links included pre-schools and childcare, drinking non-habitual or untreated water supply or contact with recreational water. A surprising 17% reported faecal contact, while a small proportion reported contact with a sick animal.
Obviously, this information is confounded and incomplete and doesn’t explain exactly how the patients contracted campylobacteriosis. However, it does point to the special nature of life in New Zealand and suggests that we need to look widely to find ways to control our high incidence of campylobacteriosis.
using the keyword Campylobacter, or go to "So what is this Campylobacter thing?" posted Tuesday 21st November 2006 by clicking the Archive).
How do you know chicken is safe to eat? If you cook it yourself, use a meat thermometer to check the internal temperature reaches 74 C (165 F). The USDA suggests 160 F (71.1 C) for beef burgers. If you buy chicken ready-cooked for reheating, use the same temperatures. If you are going to eat pre-cooked chicken without further heating, make sure you trust the supplier.
* The 12 month rate is based on the cumulative total for the current year (12 months up to and including March 2008), expressed as cases per 100,000
I looked through some recent stats and found that the most common questions referred to the safety of chicken (by far the most frequent referral), unpasteurized milk, coliforms and how bacteria can get into food. There were one or two surprising enquiries, but I won’t go into those.
Over the next few posts I’ll visit some of the more popular questions, starting with a report from New Zealand on campylobacteriosis and poultry.
The March 2008 Monthly Surveillance Report from ESR makes for interesting reading. http://www.surv.esr.cri.nz/surveillance/monthly_surveillance.php?
we_objectID=1548
The incidence of campylobacteriosis in the human population of New Zealand has fallen again. 450 campylobacteriosis cases were notified in March 2008 compared with 1145 cases notified in the same month of the previous year. The current 12 month rate* is 234 cases per 100,000 head of population, compared with 386 for the previous 12 months to March 2007 – a 39% reduction. Compared with the rates of other infectious diseases surveyed, this is a very significant achievement.
Though there is currently no direct evidence, at least some of this reduction must be because of the strenuous efforts made by the poultry industry to reduce the levels of contamination on fresh poultry and poultry products.
The Campylobacter surveillance data contain other interesting observations on the possible source of infection: of the cases where the information was recorded, 51% had eaten food from a food premise (I assume that means a restaurant or take-away); 38% had contact with farm animals; 22% had contact with other people showing symptoms of campylobacteriosis. Other possible links included pre-schools and childcare, drinking non-habitual or untreated water supply or contact with recreational water. A surprising 17% reported faecal contact, while a small proportion reported contact with a sick animal.
Obviously, this information is confounded and incomplete and doesn’t explain exactly how the patients contracted campylobacteriosis. However, it does point to the special nature of life in New Zealand and suggests that we need to look widely to find ways to control our high incidence of campylobacteriosis.
How do you know chicken is safe to eat? If you cook it yourself, use a meat thermometer to check the internal temperature reaches 74 C (165 F). The USDA suggests 160 F (71.1 C) for beef burgers. If you buy chicken ready-cooked for reheating, use the same temperatures. If you are going to eat pre-cooked chicken without further heating, make sure you trust the supplier.
* The 12 month rate is based on the cumulative total for the current year (12 months up to and including March 2008), expressed as cases per 100,000
Friday, March 28, 2008
The news just keeps on getting worse!
After so many years of living with a food microbiologist, my wife has become a valuable food retail spy. Today she told me two more horror stories:
In our local supermarket there is a display stand for unwrapped bakery goods that extends from about chest height down to the floor. The store manager has supplied tongs for customers to use and there are signs asking customers to use the tongs.
Today she arrived at the bakery counter in time to see a mother wrestling the tongs from her toddler. If this were not bad enough, the mother then said to the toddler “I thought you said you were going to eat that”. Grabbing a bun from the child’s other hand, she stuck it back in the cabinet. Now both of them had handled the bun.
Now, I realise that bread buns are not a particularly good growth medium for food poisoning bacteria, but this is unacceptable. Some food borne pathogens have a very low infecting dose. The display cabinet should be arranged so that products and tongs are inaccessible to toddlers. Owners of self-service food displays need to be aware that simply providing tongs does not guarantee the safety of the food they sell. Needless to say, we will not purchase unwrapped goods from that store again.
The second incident was observed on TVNZ’s Good Morning show. Unfortunately, I didn’t see it and have not been able to locate a replay on their website. It appears that The Mad Butcher was on the show and demonstrating the preparation of chicken. After handling the raw chicken, he put his fingers into some spices and tasted a pinch. The bowl of spices was thus contaminated with whatever bacteria were on the raw chicken. A short while later, he put a cooked chicken onto the same chopping board, contaminating it with raw poultry juices.
OK – the Mad Butcher is not a professional chef and neither is Steve Grey, the host for that segment. The poultry industry in New Zealand has had a bad press recently over Campylobacter food poisoning, allegedly transmitted largely via chicken (though in fact we have seen a significant and sustained reduction over the last year in the incidence of the disease in the human population). This sort of example on daytime television, which is probably watched by many young mothers, is perhaps one of the reasons that we see such a high incidence of campylobacteriosis in New Zealand. Young adults are not getting the food safety message and we need to have good kitchen habits shown on our national television channels. We can’t rely on the food suppliers to take total responsibility for control of food poisoning.
This type of poor kitchen practice is not confined to New Zealand; Doug Powell at Kansas State University, who runs the Food Safety Net and writes the Barfblog has castigated some TV chefs in the USA for similar indiscretions (see for example: http://barfblog.foodsafety.ksu.edu/tags/tv/).
In our local supermarket there is a display stand for unwrapped bakery goods that extends from about chest height down to the floor. The store manager has supplied tongs for customers to use and there are signs asking customers to use the tongs.
Today she arrived at the bakery counter in time to see a mother wrestling the tongs from her toddler. If this were not bad enough, the mother then said to the toddler “I thought you said you were going to eat that”. Grabbing a bun from the child’s other hand, she stuck it back in the cabinet. Now both of them had handled the bun.
Now, I realise that bread buns are not a particularly good growth medium for food poisoning bacteria, but this is unacceptable. Some food borne pathogens have a very low infecting dose. The display cabinet should be arranged so that products and tongs are inaccessible to toddlers. Owners of self-service food displays need to be aware that simply providing tongs does not guarantee the safety of the food they sell. Needless to say, we will not purchase unwrapped goods from that store again.
The second incident was observed on TVNZ’s Good Morning show. Unfortunately, I didn’t see it and have not been able to locate a replay on their website. It appears that The Mad Butcher was on the show and demonstrating the preparation of chicken. After handling the raw chicken, he put his fingers into some spices and tasted a pinch. The bowl of spices was thus contaminated with whatever bacteria were on the raw chicken. A short while later, he put a cooked chicken onto the same chopping board, contaminating it with raw poultry juices.
OK – the Mad Butcher is not a professional chef and neither is Steve Grey, the host for that segment. The poultry industry in New Zealand has had a bad press recently over Campylobacter food poisoning, allegedly transmitted largely via chicken (though in fact we have seen a significant and sustained reduction over the last year in the incidence of the disease in the human population). This sort of example on daytime television, which is probably watched by many young mothers, is perhaps one of the reasons that we see such a high incidence of campylobacteriosis in New Zealand. Young adults are not getting the food safety message and we need to have good kitchen habits shown on our national television channels. We can’t rely on the food suppliers to take total responsibility for control of food poisoning.
This type of poor kitchen practice is not confined to New Zealand; Doug Powell at Kansas State University, who runs the Food Safety Net and writes the Barfblog has castigated some TV chefs in the USA for similar indiscretions (see for example: http://barfblog.foodsafety.ksu.edu/tags/tv/).
Saturday, February 9, 2008
That Campylobacter problem – it just doesn’t go away
It has been fascinating to watch the news reports, both here in New Zealand and overseas, over the last few weeks and see the different takes. The New Zealand Food Safety Authority announced on 15th January the introduction of a Code of Practice for the poultry industry. The code is intended to reduce the incidence of campylobacteriosis in New Zealand, which is the highest in the developed world. The code has received mixed reviews and the language used has at times been intemperate. The blame for much of this disease has been laid at the door of the poultry industry as suppliers of “New Zealand’s cheap and dirty food”. In a Radio NZ interview, Dr. Mike Baker claimed that when chicken is prepared in a kitchen, every surface in the kitchen will be covered with bacteria and the aprons of workers in restaurant kitchens will potentially be covered in a layer of Campylobacter.
When interviewed by the Taranaki Daily News, a Tegel spokesman said that the Company fully supported the new code. Sharon Wagener of NZFSA says that the code formalises a lot of what was already happening voluntarily in the industry. However, on the Green Party website their spokesman Sue Kedgley claimed that the code “fails to include some very simple measures to stem the tide of Campylobacter contamination of chicken meat being sold to New Zealanders”. Some of the points raised by Ms. Kedgley in relation to problems of mechanical handling and leaky packaging are not in dispute, but are already being addressed by the industry.
The Taranaki Medical Officer of Health, Richard Hoskins, noted that the Health Board has had interactions with Tegel (which of course is not the only chicken processor in the country) in efforts to reduce the incidence of the disease. He apparently expressed the view that the Board was "pretty impressed with the efforts they are going to".
Michael Brooks, the Executive Director of the Poultry Industry Association of New Zealand, has also stated that based on figures collected by ESR, human campylobacteriosis case rates have been steadily declining since August 2006, in some months showing a drop of 30-35% over the corresponding previous year. Of course, this does not satisfy everyone; the incidence of campylobacteriosis tends to be somewhat variable from month to month and it will require proper statistical analysis over some years to demonstrate a true decrease.
The adversarial approach being taken by some of the interested parties is not, in my view, the best way forward. Nobody has the complete right answer; where has the still small voice of reason and collaboration gone? Wouldn’t it be better if the parties worked together, using scientifically demonstrable facts and not overheated opinion to put together the jigsaw puzzle and solve the problem?
The fact is that human infection by Campylobacter is a very complex problem and simply pointing the finger at the poultry industry will not solve it, no matter what codes of practice are imposed. Take just one point: sub-typing of Campylobacter, using molecular methods, can show the relatedness of various isolates from poultry and from humans. In some parts of the country, a single sub-type is found in up to 20% of human cases and in poultry. In other parts, the sub-typing shows that human cases do not share the same types as found in poultry. Nobody is claiming that poultry does not contribute significantly to campylobacteriosis in New Zealand, but the industry takes this seriously and is doing something about it, having issued its own Broiler Growing Biosecurity Manual in consultation with NZFSA in August 2007. This describes the minimum standards to be used in NZ broiler production systems, aiming at ensuring the products meet food safety and suitability requirements and consumer needs. Campylobacter is a commensal bacterium – it is found in poultry and some other animals and does not cause them to be ill, so getting rid of it is going to require considerable effort and some cost on the part of farmers and processors.
The code comes into force on the first of March 2008.
For more information on Campylobacter, click here
When interviewed by the Taranaki Daily News, a Tegel spokesman said that the Company fully supported the new code. Sharon Wagener of NZFSA says that the code formalises a lot of what was already happening voluntarily in the industry. However, on the Green Party website their spokesman Sue Kedgley claimed that the code “fails to include some very simple measures to stem the tide of Campylobacter contamination of chicken meat being sold to New Zealanders”. Some of the points raised by Ms. Kedgley in relation to problems of mechanical handling and leaky packaging are not in dispute, but are already being addressed by the industry.
The Taranaki Medical Officer of Health, Richard Hoskins, noted that the Health Board has had interactions with Tegel (which of course is not the only chicken processor in the country) in efforts to reduce the incidence of the disease. He apparently expressed the view that the Board was "pretty impressed with the efforts they
Michael Brooks, the Executive Director of the Poultry Industry Association of New Zealand, has also stated that based on figures collected by ESR, human campylobacteriosis case rates have been steadily declining since August 2006, in some months showing a drop of 30-35% over the corresponding previous year. Of course, this does not satisfy everyone; the incidence of campylobacteriosis tends to be somewhat variable from month to month and it will require proper statistical analysis over some years to demonstrate a true decrease.
The adversarial approach being taken by some of the interested parties is not, in my view, the best way forward. Nobody has the complete right answer; where has the still small voice of reason and collaboration gone? Wouldn’t it be better if the parties worked together, using scientifically demonstrable facts and not overheated opinion to put together the jigsaw puzzle and solve the problem?
The fact is that human infection by Campylobacter is a very complex problem and simply pointing the finger at the poultry industry will not solve it, no matter what codes of practice are imposed. Take just one point: sub-typing of Campylobacter, using molecular methods, can show the relatedness of various isolates from poultry and from humans. In some parts of the country, a single sub-type is found in up to 20% of human cases and in poultry. In other parts, the sub-typing shows that human cases do not share the same types as found in poultry. Nobody is claiming that poultry does not contribute significantly to campylobacteriosis in New Zealand, but the industry takes this seriously and is doing something about it, having issued its own Broiler Growing Biosecurity Manual in consultation with NZFSA in August 2007. This describes the minimum standards to be used in NZ broiler production systems, aiming at ensuring the products meet food safety and suitability requirements and consumer needs. Campylobacter is a commensal bacterium – it is found in poultry and some other animals and does not cause them to be ill, so getting rid of it is going to require considerable effort and some cost on the part of farmers and processors.
The code comes into force on the first of March 2008.
For more information on Campylobacter, click here
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