Isolation of Escherichia coli O157:H7 in table eggs from selected farms in Ibadan: Efficacy of Lactobacillus rhamnosus GG probiotic for its control

Abstract

Background: Escherichia coli O157:H7 is an important food borne pathogen causing severe diarrhoea and hemolytic uremic syndrome. There is limited information on the control of pathogenic Escherichia coli (E. coli) from table eggs using probiotics. This study was designed to determine the occurrence of Escherichia coli O157:H7 in table eggs from poultry farms in Ibadan, Southwestern Nigeria and to assess the antibiotic sensitivity profile. The efficacy of Lactobacillus rhamnosus GG probiotic for inhibition of this pathogen was also evaluated. Methods & Materials: Three hundred and sixty (n = 360) table eggs were sampled from twelve farms in Ibadan. Isolation of Escherichia coli O157:H7 was done using selective pre-enrichment on Tryptone soy broth and Sorbitol MacConkey Agar as selective medium. Morphological and biochemical tests were done using standard procedures. Serological identification of the organism was performed using Escherichia coli O157 antisera. Total aerobic bacteria and coliform counts were done on Nutrient agar and MacConkey agar, respectively. Antibiotics susceptibility test was done using the agar disc diffusion method. Inhibitory activity of Lactobacillus rhamnosus GG probiotic against the isolates was assessed using Agar Well Diffusion Method at 108, 104 and 102 concentrations. Data were analysed using descriptive statistics and ANOVA at α 0.05. Results: The prevalence of Escherichia coli O157:H7 was 7 (9.8%) (entirely from egg shell). The Total aerobic bacteria count (Mean Log CFU) was 1.43 ± 1.65 and 4.95 ± 0.24 for egg contents and shell, respectively, and the Total coliform count was 1.36 ± 1.46 and 4.84 ± 0.33 for egg contents and shell, respectively. All isolates were resistant to Ampicillin, Ceftazidime, Cefuroxime and Amoxicillin. In all 100% of the isolates were multidrug resistant. The isolates were mostly susceptible to Ciprofloxacin (87.5%) and Ofloxacin (87.5%). Lactobacillus rhamnosus GG has inhibitory effect on 42.8%, 28.6% and 28.6% of the isolates at 108, 104 and 102 concentrations, respectively. Conclusion: The presence of multidrug resistant Escherichia coli O157:H7 in table eggs in Ibadan was established. Lactobacillus rhamnosus GG can be used for the control of Escherichia coli O157:H7. Improvement in hygiene by poultry farmers and control of the use of antibiotics in poultry is strongly recommended.