摘要
      乳酸菌（LAB）和双歧杆菌（Bifidobacterium sp.）（双歧杆菌）可以携带抗微生物耐药性基因（ARGs），但关于这些细菌耐药性机制的数据有限。我们研究的目的是通过全基因组测序来确定103个乳酸杆菌和双歧杆菌表型抗性的潜在遗传机制。测序数据不仅证实了18个菌株的基因组中存在36个获得性ARGs，而且揭示了内在ARGs的广泛传播。在已知和新的可移动遗传元件上存在获得性ARGs，增加了其水平传播的可能性。此外，我们的数据表明，突变可能是一种常见的抵抗机制。发现了几种新的候选耐药机制，为进一步的体外研究提供了基础。总体而言，在92.4%的病例中，1314种最低抑制浓度与基因型相匹配；然而，基于基因型数据的表型预测仅部分有效，尤其是氨基糖苷类和氯霉素。我们的研究揭示了乳酸杆菌和双歧杆菌的耐药性机制及其可转移性潜力，这将有助于风险评估分析。
Abstract
Lactic acid bacteria (LAB) and Bifidobacterium sp. (bifidobacteria) can carry antimicrobial resistance genes (ARGs), yet data on resistance mechanisms in these bacteria are limited. The aim of our study was to identify the underlying genetic mechanisms of phenotypic resistance in 103 LAB and bifidobacteria using whole-genome sequencing. Sequencing data not only confirmed the presence of 36 acquired ARGs in genomes of 18 strains, but also revealed wide dissemination of intrinsic ARGs. The presence of acquired ARGs on known and novel mobile genetic elements raises the possibility of their horizontal spread. In addition, our data suggest that mutations may be a common mechanism of resistance. Several novel candidate resistance mechanisms were uncovered, providing a basis for further in vitro studies. Overall, 1,314 minimum inhibitory concentrations matched with genotypes in 92.4% of the cases; however, prediction of phenotype based on genotypic data was only partially efficient, especially with respect to aminoglycosides and chloramphenicol. Our study sheds light on resistance mechanisms and their transferability potential in LAB and bifidobacteria, which will be useful for risk assessment analysis.

https://www.life-science-alliance.org/content/6/4/e202201637.abstract