EPIDEMIOLOGY, ECOLOGY, AND MOLECULAR GENETICS OF ANTIMICROBIAL RESISTANCE IN PATHOGENIC AND COMMENSAL BACTERIA FROM FOOD ANIMALS
Location: Bacterial Epidemiology and Antimicrobial Resistance
Title: The rise and fall of salmonella enteritidis in poultry: implications for human health
Submitted to: Annual Conference of Antimicrobial Resistance
Publication Type: Abstract Only
Publication Acceptance Date: February 1, 2010
Publication Date: February 1, 2010
Citation: Cray, P.J., Cox Jr, N.A., Frye, J.G., Richardson, L.J., Haro, J.H. 2010. The rise and fall of salmonella enteritidis in poultry: implications for human health. Annual Conference of Antimicrobial Resistance. February 1-3, 2010. Bethesda, Maryland. P10. 79.
Objective: Describe how the dynamic of Salmonella prevalence within an animal species is serotype specific. Background: Among the >2500 Salmonella serotypes, infection with serovar Enteritidis can result in increased morbidity and mortality. Although the overall incidence of food borne salmonellosis has decreased, recent increases are attributed to infection with Enteritidis. We hypothesized that industry efforts to control a less virulent but prevalent serovar , Kentucky, may have affected this increase. Methods: Serotype data (%within chickens) collected from 1997 through 2008 as part of the National Antimicrobial Resistance Monitoring System were analyzed. Serovars Kentucky, Enteritidis, Heidelberg, Typhimurium, and Typhimurium var. 5- (Typh5-; in decreasing order of frequency) represented the top five serovars recovered from chickens in 2008 and were used as the baseline. Statistics were conducted using SAS/LAB version 9.2. Results: Collectively, these five serovars represented between 61% in 1997 to 84% in 2006 of all isolates recovered from chickens. For all years neither Typhimurium nor Typh5- exceeded 9% of the serovars recovered. However, Kentucky significantly increased (p<0.01) from 25% in 1997 to 50% in 2006, and significantly decreased (p<0.01) to 35% in 2008. Conversely, Heidelberg significantly decreased (p<0.01) from 24% tin 1997 to 15% in 2008 while Enteritidis significantly increased (p<0.01) from <1% in 1997 to 18.6% in 2008. Interestingly, for the past five years, the average percent recovery by year has remained steady at 80%. Conclusions: In an attempt to control the increasing prevalence of Kentucky, the poultry industry implemented control measures in 2005. These efforts may have resulted in displacement of Kentucky as well as Heidelberg over time while permitting replacement with Enteritidis. Interestingly, neither Typhimurium nor Typh5- appears to be affected. These data suggest that the host/microbe interaction is complex and control may require additional efforts.