摘要
      乳酸菌（LAB）和双歧杆菌可能是抗微生物耐药性的宿主，但故意引入农产品食物链的菌株所带来的风险尚未得到彻底调查。我们研究的目的是评估益生菌、发酵剂和保护性培养物以及饲料添加剂是否对人类健康构成风险。除了实验室和双歧杆菌的商业菌株外，还分析了母乳或初乳、肠粘膜或粪便以及发酵产品中的分离物。474株菌株的表型易感性数据显示，肠道分离株比商业菌株更常见抗微生物耐药性。利用比较基因组学对1114株菌株的全基因组序列中的抗微生物耐药性基因（ARGs）和可移动遗传元件（MGEs）进行了表征。内源性ARG在肠球菌、双歧杆菌和乳球菌中含量丰富，但由于缺乏MGE，被认为是无风险的。结果显示，13.8%的商业菌株含有获得性ARGs，最常见的是四环素。我们将75.5%的获得性ARGs与已知或新的MGE相关联，并通过检查宏基因组序列来评估其传播潜力。我们证实，商业菌株中的ARGs和MGE不如人类肠道分离株或母乳分离株中的丰富或多样，这表明有意引入农业食品链的菌株不会构成重大威胁。然而，应特别注意含有已被证明在肠道微生物群中具有高转移潜力的元素的单个益生菌菌株。
ABSTRACT
Lactic acid bacteria (LAB) and bifidobacteria may serve as reservoirs of antimicrobial resistance, but the risk posed by strains intentionally introduced into the agro-food chain has not yet been thoroughly investigated. The aim of our study was to evaluate whether probiotics, starter and protective cultures, and feed additives represent a risk to human health. In addition to commercial strains of LAB and bifidobacteria, isolates from human milk or colostrum, intestinal mucosa or feces, and fermented products were analyzed. Phenotypic susceptibility data of 474 strains showed that antimicrobial resistance was more common in intestinal isolates than in commercial strains. Antimicrobial resistance genes (ARGs) and mobile genetic elements (MGEs) were characterized in the whole genome sequences of 1114 strains using comparative genomics. Intrinsic ARGs were abundant in enterococci, bifidobacteria, and lactococci but were considered non-risky due to the absence of MGEs. The results revealed that 13.8% of commercial strains contained acquired ARGs, most frequently for tetracycline. We associated 75.5% of the acquired ARGs with known or novel MGEs, and their potential for transmission was assessed by examining metagenomic sequences. We confirmed that ARGs and MGEs were not as abundant or diverse in commercial strains as in human intestinal isolates or isolates from human milk, suggesting that strains intentionally introduced into the agro-food chain do not pose a significant threat. However, attention should be paid especially to individual probiotic strains containing elements that have been shown to have high potential for transferability in the gut microbiota.

https://www.tandfonline.com/doi/full/10.1080/19490976.2022.2127438