Department of Microbiology and Fermentation Technology, CSIR- Central Food Technological Research Institute, Mysuru, 570020, India.
Department of Developmental Biology and Genetics, Indian Institute of Science, Bangalore, 560012, India.
Curr Microbiol. 2024 Aug 6;81(9):297. doi: 10.1007/s00284-024-03826-2.
The overuse of colistin, the last-resort antibiotic, has led to the emergence of colistin-resistant bacteria, which is a major concern. Lactic acid bacteria which are generally regarded as safe are known to be reservoirs of antibiotic resistance that possibly pose a threat to human and animal health. Therefore, this study assessed the prevalence of colistin antimicrobial resistance in livestock in India, that is lactic acid bacteria in healthy chickens, sheep, beef, and swine of Mysore. Diverse phenotypic and genotypic colistin resistance were examined among the lactic acid bacterial species (n = 84) isolated from chicken (n = 44), sheep (n = 16), beef (n = 14), and swine (n = 10). Hi-comb, double-disk diffusion tests, Minimum Inhibitory Concentration (MIC), and biofilm formation were assessed for phenotypic colistin resistance. Specific primers for colistin-resistant genes were used for the determination of genotypic colistin resistance. Around 20%, 18%, and 1% were colistin-resistant Lactobacillus, Enterococcus, and Pediococcus species, respectively. Among these, 66.67% exhibited MDR phenotypes, including colistin antibiotic. The identified resistant isolates are Levilactobacillus brevis LBA and LBB (2), Limosilactobacillus fermentum LBF (1), and Pediococcus acidilactici CHBI (1). The mcr-1 and mcr-3 genes were detected in Levilactobacillus brevis LBA, LBB, and Pediococcus acidilactici CHBI isolated from chicken and sheep intestines respectively. The study identified colistin resistance determinants in lactobacilli from food animals, emphasizing the need for enhanced surveillance and monitoring of resistance spread. These findings underscore colistin resistance as a significant medical concern and should be integrated into India's ongoing antimicrobial resistance monitoring programs.
黏菌素的过度使用导致了抗黏菌素细菌的出现，这是一个主要关注点。众所周知，通常被认为安全的乳酸菌是抗生素耐药性的储存库，可能对人类和动物健康构成威胁。因此，本研究评估了印度牲畜中黏菌素抗药性的流行情况，即在迈索尔健康鸡、羊、牛和猪的乳酸菌中。研究人员检查了从鸡（n=44）、羊（n=16）、牛（n=14）和猪（n=10）中分离出的乳酸菌物种（n=84）中存在的多种表型和基因型黏菌素耐药性。使用 Hi-comb、双圆盘扩散试验、最低抑菌浓度（MIC）和生物膜形成试验评估了表型黏菌素耐药性。使用针对特定的黏菌素耐药基因的引物来确定基因型黏菌素耐药性。结果显示，乳酸菌中分别有 20%、18%和 1%的乳杆菌属、肠球菌属和戊糖片球菌属对黏菌素耐药。其中，66.67%表现出多药耐药表型，包括黏菌素抗生素。鉴定出的耐药分离株是从鸡和羊的肠道中分离出的短乳杆菌 LBA 和 LBB（2）、发酵乳杆菌 LBF（1）和戊糖片球菌 CHBI（1）。在从鸡和羊肠道中分离出的短乳杆菌 LBA、LBB 和戊糖片球菌 CHBI 中检测到 mcr-1 和 mcr-3 基因。本研究从食用动物的乳酸菌中鉴定出黏菌素耐药决定因子，强调需要加强对耐药性传播的监测。这些发现突显了黏菌素耐药性作为一个重大的医学关注点，并应纳入印度正在进行的抗微生物药物耐药性监测计划中。
