Isolation and Characterization of Lactic Acid Bacteria (LAB) from Bovine Milk and Study of their Antibiotic Susceptibility Patterns

Oct 6, 2026

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The present study focuses on the isolation, characterization, and antimicrobial susceptibility testing (AST) of lactic acid bacteria (LAB) from bovine milk samples obtained from Gir, Mehsana, and Holstein Friesian breeds in the Thane district of India. LAB isolates were characterized morphologically and biochemically and identified using MALDI-TOF MS. Seven Gram-positive, catalase-negative isolates were tested for antibiotic sensitivity using antibiogram assays interpreted according to CLSI (2015) guidelines, revealing extensive resistance patterns across commonly used antibiotics and highlighting implications for probiotic safety and efficacy.

LanguageEnglish

CategoryHealthcare

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Pages22

Reading Time55 min

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Abstract

Introduction

Materials and Methods

Scopus Indexed Journal December 2024 Bioscene Bioscene Volume-21 Number-04 ISSN: 1539-2422 (P) 2055-1583 (O) [www.explorebioscene.com](www.explorebioscene.com) 736 Scopus Indexed Journal December 2024 Isolation and Characterization of Lactic Acid Bacteria (LAB) from Bovine Milk and Study of their Antibiotic Susceptibility Patterns 1Mandavkar S; 2Attar A; 3Bhadane A;4Bidvi S; 5Posam M; 6Ware N; 7Choure RG; 8Jangam SK; 9Jadhav RS Department of Microbiology, The Institute of Science, Mumbai, India *Corresponding Author: Jadhav RS Abstract: The present study focuses on the isolation, characterization, and antimicrobial susceptibility testing (AST) of lactic acid bacteria (LAB) from bovine milk samples obtained from Gir, Mehsana, and Holstein Friesian breeds in the Thane district of India. The LAB isolates were characterized morphologically and biochemically and identified using MALDI-TOF MS.Seven Gram-positive, catalase-negative isolates were used in this study. Antibiogram tests were performed to record the sensitivity or resistance of LAB towards antibiotics and results were interpreted according to the CLSI (2015) guidelines. Leuconostocpseudomesenteroide from the HF cow milk was resistant to all 18 tested antibiotics. Lactobacillus plantarum and Lactobacillus caseishowed resistance to 16 and 15 out of 18 tested antibiotics respectively. Lactococcus lactis showed sensitivity to 6 tested antibiotics. All isolated LAB from bovine milk were resistant to oxacillin, vancomycin, ofloxacin, teicoplanin, ceftazidime, gentamycin, co-trimoxazole, and cloxacillin antibiotics.This study contributes to the ongoing efforts to understand the prevalence and implications of antibiotic resistance in probiotic bacteria, which is crucial for ensuring the safety and efficacy of probiotic products. Keywords: Antibiotic susceptibility, Probiotic, Lactic acid bacteria, Bovine milk Introduction Probiotics are consumed globally in various forms, including food, dietary supplements, and as active components of registered medications. However, thereis a need to reassess their safety, particularly regarding the potential spread of antibiotic resistance (ABR) (Sukmariniet al. , 2014). While antibiotic resistance is a significant concern, it has not received sufficient attention in the context of lactic acid bacteria (LAB), the most commonly consumed bacterial group. The ability of LAB to help maintain or replenish beneficial gut microbiota has garnered significant attention for probiotics as health promoters. LABs have along-standing ‘Generally Recognized as Safe (GRAS)’ status by the U.S. Food and Drug Administration (FDA) and are also candidates for Qualified Presumption of Safety (QPS) status by the European Food Safety Authority (EFSA) . Numerous research studies and reports have provided safety assurances for LAB, contributing to the growing interest in probiotics. The probiotic concept has evolved from traditional dairy products to a profitable market, where probiotic 737 Scopus Indexed Journal December 2024 bacteria are incorporated into various dairy products, health supplements, and functional foods (Arioli et al., 2013) . The probiotic market has witnessed substantial growth in recent decades. The global market for probiotic supplements was valued at nearly $7 billion in 2021 and projected to grow at a compound annual growth rate (CAGR) of 9.3% from 2022 to 2023 (Zavišić G. et al., 2023). This growth is driven by increasing consumer demand for healthy foods and nutritional supplements and a lifestyle focused on personal health and wellness. There is a high possibility of horizontal gene transfer among bacteria in nature, leading to the further spread of these resistant strains between populations (Sukmariniet al. , 2014) . In the last decade, there has been an increase in reports documenting antibiotic resistance in LAB strains. Although LABs are generally considered safe, concerns exist regarding the poss

FAQs

What was the main purpose of the study?

To isolate and characterize lactic acid bacteria (LAB) from bovine milk and determine their antibiotic susceptibility patterns using antimicrobial susceptibility testing (AST).

How were the LAB isolates identified?

The isolates were characterized morphologically and biochemically, then identified using MALDI-TOF MS.

How were the antibiotic susceptibility results interpreted?

Results from antibiogram tests were interpreted according to the CLSI (2015) guidelines.

Oct 6, 2026

Uploaded by cksankcs