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United States Department of Agriculture

Agricultural Research Service

Research Project: Monitoring of Antimicrobial Resistance in Food Animal Production

Location: Bacterial Epidemiology & Antimicrobial Resistance Research

Title: Highlights of the NARMS 2009 Executive Report)

Author
item Mcdermott, Patrick
item Whichard, Jean
item Cray, Paula
item Tate, Heather
item Karp, Beth
item Haro, Jovita
item Plumblee, Jodie

Submitted to: World Wide Web
Publication Type: Research technical update
Publication Acceptance Date: 9/7/2011
Publication Date: 9/7/2011
Citation: McDermott, P., Whichard, J., Cray, P.J., Tate, H., Karp, B., Haro, J.H., Plumblee, J. 2011. Highlights of the NARMS 2009 Executive Report. Available: http://www.fda.gov/downloads/AnimalVeterinary/SafetyHealth/AntimicrobialResistance/NationalAntimicrobialResistanceMonitoringSystem/UCM275775.pdf

Interpretive Summary:

Technical Abstract: Salmonella Isolates by Source During 2009, NARMS tested 2,192 isolates of non-typhoidal Salmonella from humans, 489 from retail meats, and 992 from food animals. • The most common serotypes in humans, in order of frequency were Enteritidis (18.7%), Typhimurium (16.9%), Newport (10.8%), Javiana (4.8%), Heidelberg (3.9%), and I 4,[5],12:i:- (3.3%). • The percent of retail chicken breast (CB) samples that tested positive for Salmonella increased from 9.2% in 2007 to 15.2% in 2008, and then to 21% in 2009. The proportion of CB isolates that carried serotype Typhimurium rose from 13.8% in 2006 (the lowest prevalence since testing began) to 44.4% in 2009. • The percent of ground turkey (GT) isolates that were serotype Saintpaul increased from 12% to 40% between 2008 and 2009, while serotypes Hadar and Saintpaul decreased. Antimicrobial Resistance-Salmonella The NARMS 2009 Executive Report provides detailed data on resistance to clinically important antimicrobial agents. Resistance to three antimicrobial classes important for treating Salmonella infections in humans is highlighted below. Cephems • Ceftriaxone resistance increased in CB isolates between 2007 and 2009, from 16.2% to 37.6%, following a steady decline from 26.5% in 2003 to 16.2% in 2007. • In humans, 32% of the ceftriaxone-resistant Salmonella isolates were serotype Typhimurium; 24% were Heidelberg; 20% were Newport; and 6.7% were Infantis. • The percentage of ceftriaxone-resistant Heidelberg isolates more than doubled in humans and chickens and almost doubled in CB between 2008 and 2009. • In chickens and CB, ceftriaxone resistance was found predominately in serotypes Kentucky, Typhimurium and Heidelberg, whereas ceftriaxone-resistant cattle isolates were mostly serotypes Newport, Dublin, and Typhimurium. Quinolones Resistance to nalidixic acid, an elementary quinolone, is correlated with decreased susceptibility to fluoroquinolones, a class of drugs important for treating salmonellosis. • In 2009, all Salmonella isolated from GT, pork chops (PC), chickens and swine were susceptible to nalidixic acid. Among the other sources, nalidixic acid resistance was less than 2%, with the exception of ground beef (GB) which had low isolation of Salmonella. • Among nalidixic acid-resistant isolates from humans, Enteritidis was the most common serotype (38.5%), followed by Typhimurium (20.5%). Potentiated Sulfonamides • Resistance to trimethropim-sulfamethoxazole has remained low (<5%) over the years in isolates from all sources, except for PC which had low isolation. Multidrug Resistance • In 2009, 83.2% of human Salmonella isolates were not resistant to any antimicrobial agent tested, increasing steadily from 66.1% in 1996. • Among retail meats and food animals, the percentage of isolates with no resistance detected was highest in bovine (68.5% for cattle and 57.1% for GB) and lowest in turkeys (19.8% in turkeys and 22.1% in GT). • Among CB in 2009, there was no resistance detected in 29.2% of isolates; the lowest it’s been since retail testing began in 2002. An important multidrug resistance pattern in Salmonella is the combined resistance to ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline (ACSSuT). This pattern is associated with more severe and invasive disease in humans. • In human Salmonella isolates, ACSSuT resistance declined from 10.1 % in 2001 to 5.1% in 2009. The most common serotypes among ACSSuT-resistant isolates were Typhimurium (64.3%) and Newport (13.4%). This decline may reflect in part the decline in Salmonella ser. Typhimurium DT104, an ACSSuT-resistant strain of Salmonella that emerged in the late 1980s and has caused several outbreaks. • In cattle isolates, the ACSSuT pattern declined from 18.1% in 2008 to 15.0% in 2009, and was most common in serotypes Typhimurium and Newport. • In swine, ACSSuT resistance incre

Last Modified: 8/24/2016
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