title: Occurrence and antimicrobial resistance of pathogenicEscherichia coliandSalmonellaspp. in retail raw table eggs sold for human consumption in Enugu state, Nigeria.
abstract: OBJECTIVE
  This study was conducted to investigate the occurrence of pathogenicEscherichia coliandSalmonellaspecies in retail raw table eggs sold for human consumption in Enugu State and to determine the resistance of these pathogens to antimicrobials commonly used in human and veterinary practices in Nigeria.
  
  
  METHODS
  A total of 340 raw table eggs comprising 68 composite samples (5 eggs per composite sample) were collected from five selected farms (13 composite samples from the farms) and 10 retail outlets (55 composite samples from the retail outlets) in the study area over a period of 4-month (March-June, 2014). The eggs were screened for pathogenicE. coliandSalmonellaspecies following standard procedures within 24 h of sample collection. Isolates obtained were subjected toin-vitroantimicrobial susceptibility test with 15 commonly used antimicrobials using the disk diffusion method.
  
  
  RESULTS
  About 37 (54.4%) and 7 (10.3%) of the 68 composite samples were positive for pathogenicE. coliandSalmonellaspecies, respectively. The shells showed significantly higher (p<0.05) contaminations than the contents for both microorganisms. The eggs from the farms showed higher contamination with pathogenicE. colithan eggs from the retail outlets while the reverse was the case forSalmonellaspecies even though they were not significant (p>0.05). The organisms obtained showed a multiple drug resistance. They were completely resistant to nitrofurantoin, sulfamethoxazole/trimethoprim, penicillin G and oxacillin. In addition to these,Salmonellaspp. also showed 100% resistance to tetracycline. The pathogenicE. coliisolates obtained were 100% susceptible to gentamicin, neomycin, ciprofloxacin, and amoxicillin-clavulanic acid whileSalmonellaspp. showed 100% susceptibility to erythromycin, neomycin, and rifampicin. Both organisms showed varying degrees of resistance to streptomycin, amoxicillin, vancomycin, and doxycycline.
  
  
  CONCLUSIONS
  From the results of the study, it can be concluded that the raw table eggs marketed for human consumption in Enugu State, Nigeria is contaminated with pathogenicE. coliandSalmonellaspecies that showed multiple drug resistance to antimicrobial agents commonly used in veterinary and human practice.
authors.affiliation: Department of Veterinary Public Health and Preventive Medicine, Faculty of Veterinary Medicine, University of Nigeria, Nsukka, Enugu State, Nigeria.
authors.forename: O Josephine
authors.initials: OJ
authors.lastname: Okorie-Kanu
authors.affiliation: Department of Veterinary Public Health and Preventive Medicine, Faculty of Veterinary Medicine, University of Nigeria, Nsukka, Enugu State, Nigeria.
authors.forename: E Vivienne
authors.initials: EV
authors.lastname: Ezenduka
authors.affiliation: Department of Veterinary Pathology, Michael Okpara University of Agriculture, Umudike, Abia State, Nigeria.
authors.forename: C Onwuchokwe
authors.initials: CO
authors.lastname: Okorie-Kanu
authors.affiliation: Department of Veterinary Public Health and Preventive Medicine, Faculty of Veterinary Medicine, University of Nigeria, Nsukka, Enugu State, Nigeria.
authors.forename: L Chinweokwu
authors.initials: LC
authors.lastname: Ugwu
authors.affiliation: Department of Veterinary Public Health and Preventive Medicine, Faculty of Veterinary Medicine, University of Nigeria, Nsukka, Enugu State, Nigeria.
authors.forename: U John
authors.initials: UJ
authors.lastname: Nnamani
keywords: Salmonella species; antimicrobial agents; farms; pathogenic Escherichia coli; retail outlets; table eggs