Aim:This study was conducted to investigate the occurrence of pathogenic Escherichia coli and Salmonella species 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.Materials and 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 pathogenic E. coli and Salmonella species following standard procedures within 24 h of sample collection. Isolates obtained were subjected to in-vitro antimicrobial 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 pathogenic E. coli and Salmonella species, 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 pathogenic E. coli than eggs from the retail outlets while the reverse was the case for Salmonella species 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, Salmonella spp. also showed 100% resistance to tetracycline. The pathogenic E. coli isolates obtained were 100% susceptible to gentamicin, neomycin, ciprofloxacin, and amoxicillin-clavulanic acid while Salmonella spp. showed 100% susceptibility to erythromycin, neomycin, and rifampicin. Both organisms showed varying degrees of resistance to streptomycin, amoxicillin, vancomycin, and doxycycline.Conclusion: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 pathogenic E. coli and Salmonella species that showed multiple drug resistance to antimicrobial agents commonly used in veterinary and human practice.

This study was conducted to isolate enterococci from dogs in Nigeria, and to determine the potential virulence, antibiotic susceptibility, phenotypic vancomycin (VAN), high-level ampicillin (AMP) and aminoglycosides susceptibility profile of the isolates. Rectal swabs were collected from 295 randomly-selected, clinically-healthy dogs. The isolation of enterococci was done using Slanetz and Bartley enterococcal selective medium. The resistance of 150 non-repetitive isolates was determined using disc diffusion method. VAN resistance was assessed by high-level disc diffusion and agar-screening methods. High-level AMP and aminoglycosides (gentamicin and streptomycin) resistance was determined by agar-screening method. Potential virulence factors were assayed using phenotypic methods. Out of 295 samples, 234 (80.7%) gave positive growth. From these, 250 enterococcal isolates comprised 229 (91.6%) non-pigmented and 21 (8.4%) pigmented strains, were obtained. Resistance of the isolates was 89% to erythromycin, 92% to rifampicin, 77% to chloramphenicol, 83% to tetracycline, 64% to ciprofloxacin, 32.7% to VAN, 24.7% to high-level streptomycin (HLS) and 6% to high-level gentamicin (HLG). Among 150 non-repetitive resistant isolates, 144 (96%), including all the VAN-, HLS- and HLG-resistant strains, exhibited resistance to at least 3 classes of antibiotics. The mean multiple antibiotic resistance index was 0.54 (range = 0.22 – 0.89). Of these 150 isolates, 94 (62.7%), including all the VAN-, HLS- and HLG-resistant strains, displayed virulence potentials as biofilm (44.7%), surface-layer (13.8%), haemolysin (21.3%), gelatinase (40.4%), caesinase (10.6%) and deoxyribonuclease (12.8%) activities. This study showed that dogs in Nigeria are potential reservoirs and disseminators of potentially-virulent, multidrug-, VAN- and high-level aminoglycosides-resistant enterococci.