Prevalence and Antimicrobial Resistance in Escherichia coli from Food Animals in Lagos, Nigeria

Microb Drug Resist. 2015 Jun;21(3):358-65. doi: 10.1089/mdr.2014.0222. Epub 2015 Feb 6.

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 Sensititre™ 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%) samples from cattle, chicken, and swine, respectively, were positive for E. coli. A subset of those isolates (n=211) selected based on β-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 on 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.

MeSH terms

  • Animals
  • Anti-Bacterial Agents / pharmacology
  • Cattle
  • Cattle Diseases / drug therapy
  • Cattle Diseases / epidemiology*
  • Cattle Diseases / microbiology
  • Disease Reservoirs / microbiology
  • Disease Reservoirs / veterinary*
  • Drug Resistance, Multiple, Bacterial / genetics*
  • Electrophoresis, Gel, Pulsed-Field
  • Escherichia coli / drug effects
  • Escherichia coli / enzymology
  • Escherichia coli / genetics*
  • Escherichia coli / isolation & purification
  • Escherichia coli Infections / drug therapy
  • Escherichia coli Infections / epidemiology
  • Escherichia coli Infections / microbiology
  • Escherichia coli Infections / veterinary*
  • Feces / microbiology
  • Humans
  • Microbial Sensitivity Tests
  • Nigeria / epidemiology
  • Poultry
  • Poultry Diseases / drug therapy
  • Poultry Diseases / epidemiology*
  • Poultry Diseases / microbiology
  • Prevalence
  • Swine
  • Swine Diseases / drug therapy
  • Swine Diseases / epidemiology*
  • Swine Diseases / microbiology
  • beta-Lactamases / genetics

Substances

  • Anti-Bacterial Agents
  • beta-Lactamases