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U.S. Department of Health and Human Services

Animal & Veterinary

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Surveillance in Retail Meats by Shaohua Zhao, DVM, MPVM, Ph.D., FDA

DR. ZHAO: Thank you, Heather. Good morning. Today I would just like to briefly reports the NARMS retail meat program. I will focus on the prevalence and the antimicrobial resistance --- and the Campylobacter. Tomorrow my colleague, Doctor Johnnie Davis and myself will report Enterococci and E. coli data.

(Slide)

NARMS retail meat program is a collaborative effort between FDA, CVM, and the public health laboratory for the FoodNet sites. The program started a little bit later compared to human and the animal NARMS program, we started in 2002 and initially we have five FoodNet sites participate. And each year we added additional two sites into the program. By the 2008 we have total 11 sites participants in the program.

(Slide)

The sampling scheme and each sites were visited at least one the closes one per month and each site that were purchased ten pack each of food chicken breasts, pork chops, ground beef and ground turkey. All the 11 sites were tried to isolate the Salmonella and the Campylobacter and the four sites culture for E. coli and Entercococcus. And in 2005 our sampling scheme is changing from the convenience sampling to the random sampling.

(Slide)

This slide shows the number of the meat sampling has been analyzed for each year. So you can see for the seven years that we have total, analyze over 29 meat samples.

(Slide)

This slides shows some prevalence of Salmonella between 2000 and 2008 from four meat commodity. So you can see the most contaminated meat is chicken -- ground chicken and ground turkey and chicken breasts. And beef and pork has less than two percent over the years. So you can see over the years the data is quite consistent.

(Slide)

So far we have identified a total of 62 serotype --- they have more than 200 serotype, so we have a list of that. But the top serotype, Typhimurlum, Heidelberg, Kentucky, Hadar, Saintpaul, Enteritidis, Reading, Schwartzengru, Montevideo and Senftenberg. If you look at those there exact report, you can see that there is quite a correlation between the human and the animal species.

(Slide)

This slide shows the antimicrobial resistance for --- for Salmonella, over the seven years we do not identified a single isolate resistant to --- and the ---. And the most of the resistance is the tetracycline followed by streptomycin, ampicillin, ---.

We have about nine to 50 percent of isolates shows a resistance to second generation of ---, and Tri/Axo which is a really public concern because Tri/Axo is a drug of choice to treat the children Salmonellosis.

(Slide)

We have so far identified the 257 Tri/Axo resistance Salmonella recovered from retail meats. That represents almost 12 percent of total Salmonella recovered from 2002 to 2008. All the Tri/Axo resistance Salmonella contains the cmy gene. We also, you know, screening for other beta --- except --- we have not found any single isolates contained the ctx, the oxa and sh, which is a little different from European countries.

Forty-five percent of Tri/Axo isolates show resistance to seven or more antimicrobials. So you can see they are really multi-drug resistant.

(Slide)

The resistance to Tri/Axo --- over the year we have see this bring to many different serotypes, initially we only see in the summer --- S. Newport, but over the years we have seen -- so far we have identified 20 different Salmonella serotype that contain the same Y gene, most of them isolates from the, you know, from the ground turkey.

(Slide)

This is a PFGE profile for Hadar, Kentucky and the Heidelberg, the top 10 serotype. So you can say, you know, we have identified the clone, this is three clones also identified through the seven different years, and for the Hadar. Most from the chicken and the turkey. And the most resistance is the streptomycin and the tetracycline, we have only one isolate that is susceptible but most of them is in two different antimicrobials.

(Slide)

And this is S. Kentucky clone again we find from the seven different years and from different states. Most of them are susceptible, we have --- isolates two different drugs here. This is S. Heidelberg, resistant to two to six different antimicrobials. And they is all isolated from ground turkey from different states.

(Slide)

We also compared the, you know, MDR Salmonella to this --- databases on the human data. And we -- we found that all the MDR is collect here, associated with -- you know, this is a CDC --- on human isolates. And this is all --- isolates they all show resistance to, you know, six to nine different antimicrobials.

And there is a CDC database, you know, the public has laboratories sometimes they do not come -- conduct the --- data so the data is not available. So, we don’t know the status of this isolates with the susceptible resistance.

And this is another clone, S. Heidelberg, resistant to all five different antimicrobial. We do have human isolates as a match and this is S. Newport, it is in nine different antimicrobial and isolates of beef and also CDC databases you will have the human isolates match.
And we have those isolates because we don’t have the epidemiology, you know, the data we are not say -- those particular isolates associated with --- so we can say such a clone associated with human disease.

(Slide)

Now, I would like to briefly review the Campylobacter. This slides show the number for meat samples analyzed for Campylobacter. For the meat commodity. And because of the ground beef and the pork chop has low recovery of the Campylobacter, so 2008 we dropped it from the program. But over seven years we have total, more than 26,000 meat samples have been analyzed.

(Slide)

This slide shows the Campylobacter, prevalence of Campylobacter for a four meat commodity between 2002 and 2008. So you can see the most contaminated meat is chicken breasts, it’s about 42 to 60 percent. And the turkey we have a little bit gradual increase every year is about 1.6 percent. But I only have a few Campylobacter isolates from the ground beef and the pork chop.

(Slide)

So since of the Campylobacter isolated from chicken breasts so I would like to show the prevalence, the antimicrobial resistance profile of C. jejuni, E. coli from chicken breasts. This is slide shows the C. jejuni isolates from chicken breasts and the resistance profile and the most resistant is tetracycline, it’s about 39 to 50 percent of the years.

And then followed by cipro and then naladixic acid is about 15 to 80 percent. And we do not -- we have very few isolates resistant to erythromycin, azithromycin, clarithromycin, telithromycin. And only few isolates show gentamicin. But we know not find any isolates resistant to florfenicol.

(Slide)

Compare with the C. jejuni, E. coli resistance you can obviously you can say they have against --- it’s higher to tetracycline here, but if you compare for the C. jejuni actually they are a little bit slightly lower than --- C. jejuni. However for cipro, naladixic acid is higher, it’s between 10 to 30 percent. If you remember the C. jejuni only about around 15 to 80 percent. So, for any other, those drop again, it shows between five to 10 percent, again we do not find any isolates that show resistance to florfenicol.

(Slide)

Since erythromycin and ciprofloxacin are important drug to treat the Campylobacter infection, I would like to show you the strain of the resistance to these two drugs. So, you see for erythromycin over the year --- between 2.2 and 4.5 percent is kind of low. But for cipro is about 13.8 to 21 percent. And the nafcillin was studying the poultry farm in the late, in the September 2005. So you can see after --- high. And the 2007 reaches the 21 percent. But again 2008 shows a little bit decrease. I think this data correlated very well with the CDC’s human data.

Currently we have the task force working with CDC and the USDA, working on this, why after the -- florfenicol the resistance still is high. So we like to find out why. Research is going on. Maybe our next report have some preliminary data to share with you.

(Slide)

This is a PFGE profile of C. jejuni, E. coli, again, this is a PFGE profile by ---. This is a resistance profile by two different methods because 2002-2003 we use --- dilution. So you can see for the --- identified it from a -- this is all from chicken and clone one isolate shows resistance, two different antimicrobial. And that’s another clone, that’s most resistance to two different drugs. And again the isolates over the years from different states.

This is E. coli and two E. coli clone, again you can see the cone in general they’re more resistant to the C. jejuni. And this interesting that this particularly ---. They have exact same the resistance profile. They all, most of them come from the California but one isolate from Colorado.

And also I selected some C. jejuni clone here. They have very interesting data here because they -- not only does it correlate well with the susceptibility profile but it -- location-wise they are very strictly a particular state. For this clone, they all susceptible, they all find from Tennessee, from different year, and for this clone here, we only found it from Oregon. And another clone we only found it from California. So you can see they also correlated very well with resistance profiles.

(Slide)

So, I would like to summary our finding here. Turkey had the highest prevalence of Salmonella and the chicken has the highest prevalence of Campylobacter. Sixty-two Salmonella serotypes have been identified as the top serotype Heidelberg, Typhimunium, Kentucky, Hadar and Saintpaul.

Many Salmonella serotypes emerged to be MDR, 45 percent of isolates resistant to third generation of cephalosporin, were resistant to seven or more antimicrobials. C. coli show a higher resistance to all antimicrobials tested than C. jejuni except tetracycline. And cipro and resistant Campylobacter in 2008 shows slightly decreased compared to 2005-2007.

(Slide)

And the PFGE profiles showed that Salmonella and the Campylobacter are genetically really diverse. Many clones were detected from different states over the years and some clones were associated with human diseases.

And our surveillance program provide information on contribution of food as reservoir of antimicrobial resistant pathogens. So that is why you know we would like to continue in our program.

(Slide)

Finally, I would like to acknowledge all the people from different agencies that work on the NARMS program. Thank you.

(Applause)

DR. McDERMOTT: Thank you, Shaohua, that was a very concise summary of the retail meat work. And maybe later when we get around to the discussions we can talk about some plans we have for improving that part of the NARMS program as well.

We’re running a little bit behind on schedule, but the only really important thing to keep in mind is that the coffee does vanish at 10:45. So that as long as we get to the coffee in time, that will be a victory.

Our next speaker is Doctor Jeffrey Watts. Doctor Watts is the Director of Livestock Pharmaceuticals Discovery and Research at Pfizer. And he’s also been a very major player in the Clinical Laboratory Standards Institute on the Sub-Committee for Veterinary Antimicrobial Susceptibility Testing. And for this and other reasons we invited Doctor Watts to come today and talk about some of the activities in CLSI related to surveillance data interpretation and reporting.

So, we’re transitioning a little bit. We had the sort of shoehorn this talk into this section, but this an important topic when we talk about efforts to try and harmonize or at least agree on definitions, if we could start there, I think that would be great.

So, Doctor Watts, I’ll turn it over to you and he’ll give us an update on some of the recent activities at CLSI.