Antibiogram of Lactobacilli Isolated from Four Different Niches

Presence of antibiotic resistance in lactobacilli, invites special attention from the public health point of view as they are widely used as starter cultures and probiotics. Lactobacillus, a ubiquitous genus, is expected to have an antibiogram that vary remarkably with their source. In the present work antibiotic resistance/sensitivity of Lactobacillus species isolated from four different sources: carrot, idli batter, curd and duck faeces were assessed by the Disc diffusion assay. Contrary to the earlier reports of general sensitivity of lactobacilli to the inhibitors of cell wall synthesis, all the four Lactobacillus isolates were found to be resistant against the cell wall synthesis inhibitors ampicillin and cephalosporins (cefalexin and cefixime) irrespective of their source of isolation. However the isolates were found to be sensitive to protein synthesis inhibitors like azithromycin, tetracycline, gentamicin, clindamycin and chloramphenicol. In general the isolates were found to be more resistant to those antibiotics that act by inhibiting cell wall synthesis than those which act by inhibiting the protein synthesis. This observation of multidrug resistance by the lactobacilli isolated from different niches reemphasize the significance of considering the antibiogram study as a critical criteria while screening lactobacilli isolates for use in food formulations. Molecular level studies are indicated to have an in-depth understanding of the basis of resistance.