The aim of our study was to assess the antibiotic resistance among commercially available probiotic Lactobacilli. A total of 30 isolates were characterized after isolation from 19 commercial products, including Lactobacillus rhamnosus, Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus reuteri, Lactobacillus plantarum and Lactobacillus fermentum. All the isolates were further subjected to antibiotic susceptibility test using disc diffusion method against a total of 45 antibiotics. Most of the isolates were found to exhibit multiple resistance against some of the most commonly used antibiotics. The isolates showed high level of resistance toward nalidixic acid, vancomycin, kanamycin, teicoplanin, co-trimoxazole, amikacin, streptomycin, norfloxacin, cefepime and nitrofurantoin. Besides, isolates displayed a low level of resistance toward tobramycin, gentamicin, ampicillin, cefaclor, methicillin, penicillin, tetracycline, levofloxacin, azithromycin, chloramphenicol, amoxyclav, sulbactam, oxacillin, ofloxacin, ciprofloxacin, cloxacillin and novobiocin. All the isolates were found to be susceptible against cefatrixone, ceftazidime, cefadroxil, cefotaxime, cephalothin, cefoperazone and netillin, whereas none of the strains showed resistant to clindamycin, erythromycin, linezolid, quinupristin/dalfopristin and doxycycline. The present study showed that antibiotic resistance is prevalent in different species of probiotic strains, which may pose a food safety concern. Hence, antibiotic sensitivity should be considered as an important part of safety assessment for the evaluation of probiotics.
