Mangroliya Devangi, Adhyaru Hetvi, Kabariya Jayesh, Ramani Vimal
Department of Dairy Microbiology, College of Dairy Science, Kamdhenu University, Amreli, Gujarat, India.
Sci Rep. 2025 Feb 21;15(1):6320. doi: 10.1038/s41598-025-90761-2.
Antimicrobial resistance in raw milk is a critical challenge for public health. This study aimed to investigate the in-vitro and in-silico analysis of antimicrobial resistance, mutations, virulence factors (VFs), mobile genetic elements, and diversity of Escherichia coli in cattle raw milk of Gujarat, India during May 2023- April 2024. 56 isolates were recovered from 50 raw milk samples. Among them, 26 were identified as E. coli and subjected to antimicrobial susceptibility testing. The extensively drug-resistant 10 isolates were further confirmed by 16s rRNA identification. Whole-genome Nanopore sequencing was performed on 10 representative strains, and data were further used in bioinformatics analysis. The results revealed that wide array of ARGs and mutations were detected. Plasmid-mediated ARGs were detected in three isolates that include bla, sul2, dfrA14, aph-Id, aph(3'')-Ib, and tet(B), responsible for resistance against antibiotic classes such as beta-lactam, folate-pathway, aminoglycosides, and tetracyclines, respectively. Additionally, the conserved VFs in isolates facilitated serum survival and toxin production. The unit transposons Tn2 and Tn10 were detected in two isolates. The isolates exhibited considerable diversity, belonging to different serotypes, sequence types (ST), and phylogroups. This research provides crucial insights for developing effective monitoring, mitigation, and educational strategies to prevent the spread of pathogenic Escherichia coli through the food chain.
生牛奶中的抗菌药物耐药性是公共卫生面临的一项严峻挑战。本研究旨在对2023年5月至2024年4月期间印度古吉拉特邦牛生牛奶中大肠杆菌的抗菌药物耐药性、突变、毒力因子（VFs）、移动遗传元件及多样性进行体外和计算机模拟分析。从50份生牛奶样本中分离出56株菌株。其中，26株被鉴定为大肠杆菌并进行了抗菌药物敏感性测试。通过16s rRNA鉴定进一步确认了10株广泛耐药菌株。对10株代表性菌株进行了全基因组纳米孔测序，并将数据进一步用于生物信息学分析。结果显示检测到了大量的抗菌药物耐药基因（ARGs）和突变。在三株分离株中检测到质粒介导的ARGs，包括bla、sul2、dfrA14、aph-Id、aph(3'')-Ib和tet(B)，分别对β-内酰胺类、叶酸途径、氨基糖苷类和四环素类抗生素具有耐药性。此外，分离株中保守的VFs促进了血清存活和毒素产生。在两株分离株中检测到单位转座子Tn2和Tn10。这些分离株表现出相当大的多样性，属于不同的血清型、序列类型（ST）和系统发育群。本研究为制定有效的监测、缓解和教育策略提供了关键见解，以防止致病性大肠杆菌通过食物链传播。
