STUDY OF IN-VITRO PROBIOTIC PROPERTIES AND ANTIBIOTIC RESISTANCE IN LACTOBACILLI ISOLATED FROM COMMERCIAL PROBIOTIC PRODUCTS IN PAKISTAN

Abstract

The aim of the study was analysis of in-vitro probiotic properties and antibiotic resistance in lactobacilli isolated from commercial probiotic products from Pakistan. Lactobacilli were identified by biochemical testing and genus specific polymerase chain reaction. Probiotic properties including tolerance to low pH and bile salts, auto-aggregation, co-aggregation and antimicrobial
activity, and antibiotic resistance pattern of all isolates was determined. A total of 14 lactobacilli isolates were recovered from nine products while three products had no lactobacilli. All isolates except AB6 were tolerant to acidic condition (pH: 2). All isolates except AB13 showed growth in presence of bile salts (0.5%). Lactobacilli showed variable auto-aggregation (01-97%) and co-aggregation with E. coli and S. enteritidis (37.5±7.7-92.4±7.3 and 31.6±6.4-95.8±4.0, respectively). Nine isolates showed activity against S. enteritidis while six isolates had activity against E. coli. Lactobacilli showed higher level of resistance to meropenem (100%), imipenem (92.85%), polymyxin B (92.85%), kanamycin (92.85%) and aztreonam (78.75%), intermediate level of resistance to vancomycin (64.2%), gentamycin (57.14%) and ciprofloxacin (42.85%), low level of resistance to ampicillin (35.71%), bacitracin (35.71%), penicillin (28.5%) and tetracycline (28.50%), and no resistance to erythromycin and chloramphenicol. It was concluded that transferable antibiotic resistance is present in commercial probiotics which may pose a threat to public safety.