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ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Bacterial Epidemiology & Antimicrobial Resistance Research » Research » Publications at this Location » Publication #309800

Research Project: MOLECULAR APPROACHES FOR THE IDENTIFICATION AND CHARACTERIZATION OF ANTIMICROBIAL RESISTANCE IN FOODBORNE PATHOGENS

Location: Bacterial Epidemiology & Antimicrobial Resistance Research

Title: Prevalence and antimicrobial resistance in Escherichia coli from food animals in Lagos, Nigeria

Author
item Adenipekun, Eyitayo - Olabisi Onabanjo University
item Jackson, Charlene
item Oluwadun, Afolabi - Olabisi Onabanjo University
item Iwalokun, Bamidele - Olabisi Onabanjo University
item Frye, Jonathan
item Barrett, John
item Hiott, Lari
item Woodley, Tiffanie

Submitted to: Microbial Drug Resistance
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/2/2015
Publication Date: 2/2/2015
Citation: Adenipekun, E., Jackson, C.R., Oluwadun, A., Iwalokun, B.A., Frye, J.G., Barrett, J.B., Hiott, L.M., Woodley, T.A. 2015. Prevalence and antimicrobial resistance in Escherichia coli from food animals in Lagos, Nigeria. Microbial Drug Resistance. 21(3):385-386.

Interpretive Summary: Foodborne bacteria are often associated with human infections; these infections can become more complicated to treat if the bacteria are also resistant to antimicrobials. In this study, prevalence, antimicrobial resistance, and genetic relatedness of Escherichia coli among food producing animals from Lagos, Nigeria was investigated. From December 2012 to June 2013, E. coli were isolated from fecal samples of healthy cattle, chicken, and swine. Antimicrobial susceptibility testing against 22 antimicrobials was performed using broth microdilution. Clonal types were determined by Pulsed-Field Gel Electrophoresis (PFGE). From the analysis, 88.7%, 81%, and 89.5% of the samples from cattle, chicken, and swine, respectively, were positive for E. coli. A subset of those isolates was chosen for further study. Overall, E. coli exhibited the highest resistance to tetracycline, trimethoprim/sulfamethoxazole, and ampicillin. Approximately 40% of the isolates were pan-susceptible and none of the isolates were resistant to amikacin, cefepime, ceftazidime, ertapenem, meropenem, or tigecycline. Among the resistant isolates, 28 different resistance patterns were observed; 26 of those were characterized as multi-drug resistant (MDR; resistance to >2 antimicrobials). One isolate was resistant to 13 different antimicrobials representing five different antimicrobial classes. Using PFGE, MDR E. coli were genetically diverse and overall did not group based upon source; identical PFGE patterns were detected among isolates from different sources. These results suggest that isolates cannot be attributed to specific sources and some may be present across all of the sources. Results from this study indicate that food producing animals in Nigeria are a reservoir of MDR E. coli that may be transferred to humans via the food chain. This information is useful for policy makers and scientists as they develop prevention and control strategies for combatting antimicrobial resistance.

Technical Abstract: Foodborne bacteria are often associated with human infections; these infections can become more complicated to treat if the bacteria are also resistant to antimicrobials. In this study, prevalence, antimicrobial resistance, and genetic relatedness of Escherichia coli among food producing animals from Lagos, Nigeria was investigated. From December 2012 to June 2013, E. coli were isolated from fecal samples of healthy cattle, chicken, and swine. Antimicrobial susceptibility testing against 22 antimicrobials was performed using broth microdilution with the SensititreTM system. Clonal types were determined by Pulsed-Field Gel Electrophoresis (PFGE). From the analysis, 211/238 (88.7%), 170/210 (81%), and 136/152 (89.5%), of samples from cattle, chicken, and swine, respectively, were positive for E. coli. A subset of those isolates (n=211) selected based upon '-lactamase production was chosen for further study. Overall, E. coli exhibited the highest resistance to tetracycline (124/211; 58.8%), trimethoprim/sulfamethoxazole (84/211; 39.8%), and ampicillin (72/211; 34.1%). Approximately 40% of the isolates were pan-susceptible and none of the isolates were resistant to amikacin, cefepime, ceftazidime, ertapenem, meropenem, or tigecycline. Among the resistant isolates, 28 different resistance patterns were observed; 26 of those were characterized as multi-drug resistant (MDR; resistance to >2 antimicrobials). One isolate was resistant to 13 different antimicrobials representing five different antimicrobial classes. Using PFGE, MDR E. coli were genetically diverse and overall did not group based upon source; identical PFGE patterns were detected among isolates from different sources. These results suggest that isolates cannot be attributed to specific sources and some may be present across all of the sources. Results from this study indicate that food producing animals in Nigeria are a reservoir of MDR E. coli that may be transferred to humans via the food chain.