Zhang Chong-Miao, Yuan Qiao-Qiao, Li Yong-Qiang, Liu An
School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Key Laboratory of Northwest Water Resource, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Lett Appl Microbiol. 2024 Dec 2;77(12). doi: 10.1093/lambio/ovae120.
This study aimed to explore antibiotic resistance characteristics and species of heterotrophic endophytic bacteria (HEB) in four kinds of edible raw vegetables, including radishes, lettuces, onions, and tomatoes. A total of 144 HEB were isolated and tested for resistance to sulfamethoxazole (SMZ), tetracycline (TET), cefotaxime (CTX), and ciprofloxacin (CIP), and their species were identified by 16S rRNA gene sequencing. Antibiotic resistance genes (ARGs) and class I integron in antibiotic-resistant isolates were analyzed by polymerase chain reaction. The results showed radishes had the highest, while tomatoes had the lowest concentration of antibiotic-resistant HEB. SMZ and CTX were predominant antibiotic-resistant phenotypes in HEB. The multi-resistant phenotypes, the combinations SMZ-TET-CTX and SMZ-TET-CIP, accounted for 9.34% of all antibiotic-resistant phenotypes, mainly in radishes and lettuces. Bacillus, Pseudomonas, Staphylococcus, and Stenotrophomonas showed resistance to two antibiotics and existed in more than one kind of vegetable, and were the main carriers of sul1, sul2, blaTEM, and intI1 genes. Therefore, these four genera were considered potential hosts of ARGs in edible raw vegetables. The study provides an early warning regarding health risks associated with ingesting antibiotic-resistant bacteria through raw vegetable consumption.
本研究旨在探究萝卜、生菜、洋葱和番茄这四种可生食蔬菜中异养内生细菌（HEB）的抗生素抗性特征及种类。共分离出144株HEB，并对其进行了磺胺甲恶唑（SMZ）、四环素（TET）、头孢噻肟（CTX）和环丙沙星（CIP）的抗性测试，通过16S rRNA基因测序鉴定其种类。采用聚合酶链反应分析抗生素抗性菌株中的抗生素抗性基因（ARGs）和I类整合子。结果表明，萝卜中抗生素抗性HEB的浓度最高，而番茄中最低。SMZ和CTX是HEB中主要的抗生素抗性表型。多重抗性表型，即SMZ-TET-CTX和SMZ-TET-CIP组合，占所有抗生素抗性表型的9.34%，主要存在于萝卜和生菜中。芽孢杆菌属、假单胞菌属、葡萄球菌属和嗜麦芽窄食单胞菌属对两种抗生素表现出抗性，且存在于不止一种蔬菜中，是sul1、sul2、blaTEM和intI1基因的主要载体。因此，这四个属被认为是可生食蔬菜中ARGs的潜在宿主。该研究为通过食用生蔬菜摄入抗生素抗性细菌所带来的健康风险提供了预警。
