Effect of production batches of antibiotics on in vitro selection criterion for potential probiotic candidates.
Fifty-four potential probiotic candidates were assayed for their phenotypic susceptibility to two batches of antibiotics manufactured by the same company, using the agar disc diffusion method on de Man, Rogosa, and Sharpe (MRS) agar. Cloxacillin was generally resisted (40.0-100%), while gentamicin (3.85-20.0%) was the least resisted antibiotic. The overall percentage differences among the potential probiotics in both batches of antibiotics were 76.5% in fermented foods, 67.3% in fermented beverages, and 53.9% in infantile fecal samples, respectively. There was slightly more overall resistance in batch 1 (46.1% and 46.7%) than in batch 2 (38.4% and 40.0%) of the test antibiotics except in the multiresistance of infantile probiotic candidates (53.8% and 61.5%, respectively). Six of the probiotic candidates did not have any corresponding matching similarity profile, while none of the 54 potential probiotics had 100% antibiogram similarity profiles in both batches of the test antibiotics, despite the fact that they met some other selection criteria such as inhibition of pathogenic bacteria and survival in simulated gastric and intestinal juices and bile. It is therefore suggested that, though routine antibiotic susceptibility testing has been advocated as an essential selection criterion for potential probiotic candidates, more than one batch of antibiotic discs be used in the phenotypic antibiotic screening in developing countries like Nigeria, in order not to lose the most promising indigenous probiotic candidates, since most of the antibiotics used for antibiotic susceptibility studies are imported into the country and their origin cannot be currently fully ascertained.
Ogunshe
Adenike A O
AA
Applied Microbiology and Infectious Diseases, Department of Botany and Microbiology, University of Ibadan, Ibadan, Nigeria. adenikemicro@yahoo.com
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D024901:Drug Resistance, Multiple, Bacterial; D005243:Feces / Q000382:microbiology; D005516:Food Microbiology; D006801:Humans; D007223:Infant; D007778:Lactobacillus / Q000187:drug effects*; D008826:Microbial Sensitivity Tests / Q000379:methods*; D009549:Nigeria; D010641:Phenotype; D010865:Pilot Projects; D019936:Probiotics / Q000009:adverse effects / Q000627:therapeutic use*
D000900:Anti-Bacterial Agents