A Study on the Assessment of the Antimicrobial Susceptibility Pattern of Microorganisms Present in Yogurt

Abstract

The aim of our study is to assess the antibiotic resistance among commercially available probiotic lactobacilli. Those probioticswhich are commercially available are generally considered as safe for humans but for their high consumption there is a need to put sufficient safeguards to protect the consumers from any adverse effects. The safety of these probiotic strains are becoming essential with antibiotic resistance as an upcoming issue and their potentiality to transfer antibiotic resistance genes to pathogenic/commensally bacteria cannot be neglected. All the Lactobacillus isolates are characterized in vitro for their probiotic characteristics and antimicrobial activities against pathogens. The isolates will be resistant to NaCl (1–6%), bile salts (0.5–3%) and show good growth in the acidic conditions, while maximum growth will be observed at pH around 6.0. All the isolates will be susceptible to clinical antibiotics; also the isolates will exhibit effective aggregation and hydrophobicity studies. Based on the results, selected Lactobacillus isolates will be considered as novel and potential probiotic bacteria. Thus, further extensive research on isolation and characterization of probiotic bacteria from local dairy product and their growth optimization may be necessary for development of probiotic enriched food supplement and human health benefits through prevention and control of bacterial infections. The starter cultures generally belongs to the lactic acid bacteria group (LAB) and are considered to be safe by the US Food and Drug Administration (FDA). But, it may have role in intrinsic and extrinsic reservoirs for antibiotic resistance gene (AR). This rises the concern regarding the safety of the product as resistance gene can transfer vertically. Nevertheless, external genetic elements may induce changes that favor the horizontal transfer of resistance gene from pathogens as well as from the human intestinal micro biota, which represents a severe safety issue. Some genus of AR LAB includes Enterococcus, Lactobacillus, Lactococcus, and Streptococcus isolated from fermented probiotic yogurt. The present study revealed about the prevalence of antibiotic resistance in various species of probiotic strains, which may impose a concern of food safety. Therefore, antibiotic sensitivity must be considered as a crucial part of safety assessment for the evaluations of probiotics.

 All the Lactobacillus isolates are characterized in vitro for their probiotic characteristics and antimicrobial activities against pathogens. The isolates will be resistant to NaCl (1–6%), bile salts (0.5–3%) and show good growth in the acidic conditions, while maximum growth will be observed at pH around 6.0. All the isolates will be susceptible to clinical antibiotics; also the isolates will exhibit effective aggregation and hydrophobicity studies. Based on the results, selected Lactobacillus isolates will be considered as novel and potential probiotic bacteria. Thus, further extensive research on isolation and characterization of probiotic bacteria from local dairy product and their growth optimization may be necessary for development of probiotic enriched food supplement and human health benefits through prevention and control of bacterial infections.

The starter cultures generally belongs to the lactic acid bacteria group (LAB) and are considered to be safe by the US Food and Drug Administration (FDA). But, it may have role in intrinsic and extrinsic reservoirs for antibiotic resistance gene (AR). This rises the concern regarding the safety of the product as resistance gene can transfer vertically.

Nevertheless, external genetic elements may induce changes that favor the horizontal transfer of resistance gene from pathogens as well as from the human intestinal micro biota, which represents a severe safety issue. Some genus of AR LAB includes Enterococcus, Lactobacillus, Lactococcus, and Streptococcus isolated from fermented probiotic yogurt.

The present study revealed about the prevalence of antibiotic resistance in various species of probiotic strains, which may impose a concern of food safety. Therefore, antibiotic sensitivity must be considered as a crucial part of safety assessment for the evaluations of probiotics.