Multidrug resistant enterohaemorrhagic Escherichia coli O157:H7 in pigeons in Ibadan, Nigeria

  • Elizabeth A. Amosun
  • Daniel I. Aweda
  • Olufemi E. Ojo
Keywords: EHEC O157, H7, Environmental contamination, Faeces, Multidrug resistance, Pigeon


Pigeons are commonly seen around human dwellings and in city centres. The movement of these birds from place to place makes them a veritable vehicle for environmental dissemination of pathogens. Enterohaemorrhagic E. coli (EHEC) O157:H7 can cause severe and sometimes fatal gastroenteritis in humans. This study investigated the occurrence and antimicrobial susceptibility of EHEC O157:H7 in the faeces. One hundred and twenty five cloacae samples (82 adult pigeons and 43 squabs) were collected from three different locations in Ibadan metropolis. Enterohaemorrhagic E. coli O157:H7 was isolated from samples on BCIG-SMAC following a selective pre-enrichment culture in modified Tryptic Soy Broth supplemented with novobiocin. Suspected non-sorbitol fermenting E. coli isolates were serologically identified as serotype O157:H7 using latex agglutination method. Enterohaemorrhagic E. coli isolates were tested for susceptibility to antimicrobial agents by the Kirby Bauer disk diffusion method. Out of all 125 samples examined, 23(18.4%) were confirmed as EHEC 0157.H7 serotype. Isolates showed resistance to nitrofuranton (100%), ceftriazone (100%), amoxicillin (91.3%), augmentin (73.9%), gentamycin (60.9%), cotrimozazole (60.9%), pefloxacin (47.8%) , tetracycline (34.8%), ciprofloxacin (30.4%) and ofloxacin (17.4%). This study showed that pigeons harbour multidrug resistant EHEC O157:H7 and may contribute to environmental contamination through faecal shedding.

Keywords: EHEC O157:H7, Environmental contamination, Faeces, Multidrug resistance, Pigeon


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eISSN: 0378-9721