EPIDEMIOLOGY, ECOLOGY, AND MOLECULAR GENETICS OF ANTIMICROBIAL RESISTANCE IN PATHOGENIC AND COMMENSAL BACTERIA FROM FOOD ANIMALS
Location: Bacterial Epidemiology and Antimicrobial Resistance
Title: Antimicrobial Resistance of Campylobacter from Retail Meats and Chicken Carcass Rinses: Results of the National Antimicrobial Resistance Monitoring System (NARMS): 2002-2006
Submitted to: American Society of Microbiologists Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: May 27, 2008
Publication Date: June 15, 2008
Citation: Cray, P.J., Mcdermott, P.F., Anandaraman, N., Plumblee, J., English, L., White, D.G. 2008. Antimicrobial Resistance of Campylobacter from Retail Meats and Chicken Carcass Rinses: Results of the National Antimicrobial Resistance Monitoring System (NARMS): 2002-2006. American Society of Microbiologists Abstracts. C163:94.
Background - Campylobacter is an important foodborne pathogen in the United States and serves as a commensal-like bacterium in many animal species. Illness in humans is thought to occur through cross-contamination during preparation of foods, particularly poultry products. The U.S. National Antimicrobial Resistance Monitoring System (NARMS) routinely tracks the antimicrobial susceptibility of Campylobacter present in the retail meat supply and on chicken carcasses at slaughter.
Methods - Campylobacter were recovered from chicken breasts (CB) purchased from grocery stores in 10 states (CA, CO, CT, GA, MD, MN, NM, NY, OR, TN) and from chicken carcasses (CC) collected at federally inspected slaughter plants. Isolates were speciated by PCR. In 2002-2003, CB isolates were tested for susceptibility to four antimicrobials (CIP, DOX, ERY, and GEN) using agar dilution; CC rinse isolates were tested against eight antimicrobials (AZI, CIP, CHL, CLI, ERY, GEN, NAL, and TET) using the Etest method from 2002-04. Starting in 2004 for CB and 2005 for CC isolates nine antimicrobials (AZI, CIP, CLI, ERY, FFC, GEN, NAL, TEL, and TET) were tested using the broth microdilution method.
Results - Overall, 64.3% and 71.2% of the CC rinse and CB isolates were C. jejuni, respectively while 35.7% and 28.7% were C. coli, respectively. Ciprofloxacin resistance in C. jejuni ranged from 18.6% (2002) to 8.8% (2006) in CC and from 15.2% (2002) to 17.5% (2006) in CB isolates. Starting in 2004, resistance to CIP among C. coli isolates was typically higher with a range from 16.0% (2002) to 15.4% (2006) and from 10.0% (2002) to 22.8% (2006) for CC rinses and CB, respectively. During the five year testing period, DOX or TET resistance consistently remained between 41.1% and 56.1% for both CC rinse and CB isolates. For 2002-2006, ERY resistance was <1% in C. jejuni from either CC or CB but in C. coli declined from 20.2% to 8.4% for CC and from 18.9% to 10.9% for CB. No isolates were resistant to CHL or FFC and, with the exception of one CC isolate, none were resistant to GEN. Susceptibility to the other antimicrobials varied, but C. coli was generally more resistant than C. jejuni regardless of source. Each year, multiple drug resistance (MDR) was observed and the most common resistance pattern among MDR strains resistant greater than >5 antimicrobials, was AZI-CLI-ERY-TEL-TET for CB and AZI-CIP-ERY-NAL-TET for CC isolates.
Conclusions – These data demonstrate that resistance varies overtime, between food sources and between bacterial species. In general resistance to the quinolones was observed to increase while resistance to the macrolides decreased. Additionally, C. coli isolates are consistently more resistant than C. jejuni. These data emphasize the need for continual monitoring.