Ohkusu Kiyofumi
Department of Microbiology, Tokyo Medical University, 6-1-1 Shinjuku-ku, Shinjuku, Tokyo 160-8402, Japan.
Biosci Microbiota Food Health. 2023;42(3):180-185. doi: 10.12938/bmfh.2022-088. Epub 2023 Jan 26.
129 BIO 3B is a lactic acid bacterium that has been safely used as a probiotic product for over 100 years. Recently, concerns about its safety have arisen because some species of belong to the vancomycin-resistant enterococci. The groups of with less pathogenic potential have been split into a separate species (). In this study, I investigated the phylogenetic classification and safety of 129 BIO 3B as well as 129 BIO 3B-R, which is naturally resistant to ampicillin. Mass spectrometry and basic local alignment search tool analysis using specific gene regions failed to differentiate 3B and 3B-R into or . However, multilocus sequence typing successfully identified 3B and 3B-R as the same sequence types as . Overall genome relatedness indices showed that 3B and 3B-R have high degrees of homology with . Gene amplification was confirmed for 3B and 3B-R with species-specific primers. The minimum inhibitory concentration of ampicillin was confirmed to be 2 µg/mL for 3B, which is within the safety standard for set by the European Food Safety Authority. Based on the above results, 129 BIO 3B and 129 BIO 3B-R were classified as . The absence of pathogenic genes except for in this study demonstrates that these bacteria are safe for use as probiotics.
129 BIO 3B是一种乳酸菌，作为益生菌产品已安全使用了100多年。最近，由于某些菌株属于耐万古霉素肠球菌，人们对其安全性产生了担忧。致病性较低的菌株组已被划分为一个单独的物种（）。在本研究中，我调查了129 BIO 3B以及对氨苄青霉素天然耐药的129 BIO 3B-R的系统发育分类和安全性。使用特定基因区域的质谱分析和基本局部比对搜索工具分析未能将3B和3B-R区分到或。然而，多位点序列分型成功地将3B和3B-R鉴定为与相同的序列类型。全基因组相关性指数表明，3B和3B-R与具有高度同源性。用物种特异性引物对3B和3B-R进行基因扩增得到证实。3B对氨苄青霉素的最低抑菌浓度经确认是2 µg/mL，这在欧洲食品安全局设定的安全标准范围内。基于上述结果，129 BIO 3B和129 BIO 3B-R被归类为。本研究中除了之外没有致病基因，这表明这些细菌作为益生菌使用是安全的。
