Haubert L, Mendonça M, Lopes G V, de Itapema Cardoso M R, da Silva W P
Departamento de Ciência e Tecnologia Agroindustrial, Universidade Federal de Pelotas (UFPel), Pelotas, RS, Brazil.
Núcleo de Biotecnologia, Centro de Desenvolvimento Tecnológico, Universidade Federal de Pelotas (UFPel), Pelotas, RS, Brazil.
Lett Appl Microbiol. 2016 Jan;62(1):23-9. doi: 10.1111/lam.12516.
Listeria monocytogenes is a foodborne pathogen that has become an important cause of human and animal diseases worldwide. The purpose of this study was to evaluate the serotypes, virulence potential, antimicrobial resistance profile, and genetic relationships of 50 L. monocytogenes isolates from food and food environment in southern Brazil. In this study, the majority of L. monocytogenes isolates belonged to the serotypes 1/2b (42%) and 4b (26%), which are the main serotypes associated with human listeriosis. In addition, all isolates harboured internalin genes (inlA, inlC, inlJ), indicating a virulence potential. The isolates were sensitive to most of the antimicrobial compounds analysed, and five isolates (10%) were multi-resistant. Two isolates harboured antimicrobial resistance genes (tetM and ermB) and in one of them, the gene was present in the plasmid. Moreover, according to the pulsed field gel electrophoresis assay, two multi-resistant isolates were a single clone isolated from food and the processing plant. The isolates were susceptible to the most frequently used antibiotics for listeriosis treatment. However, the presence of multidrug-resistant isolates and antimicrobial resistance genes including in the plasmid could even be transferred between bacterial species, suggesting a potential health risk to consumers and a potential risk of spreading multi-resistance genes to other bacteria.
Listeria monocytogenes is an important agent of foodborne diseases. The results of this study suggest a potential capacity of L. monocytogenes isolates from food and food environment to cause human infections. Antimicrobial multi-resistance profiles were detected in 10%, and two isolates harboured tetM and ermB resistance genes. Moreover, the present research can help to build up a better knowledge about antimicrobial resistance of L. monocytogenes. Additionally, we found one isolate carrying tetM resistance gene in a plasmid, that suggests a possible transmission between commensal and/or other pathogenic bacteria of food environment, thereby raising up concerns regarding bacterial resistance.
单核细胞增生李斯特菌是一种食源性病原体，已成为全球人类和动物疾病的重要病因。本研究的目的是评估从巴西南部食品和食品环境中分离出的50株单核细胞增生李斯特菌的血清型、毒力潜力、抗菌药物耐药性谱以及遗传关系。在本研究中，大多数单核细胞增生李斯特菌分离株属于血清型1/2b（42%）和4b（26%），这是与人类李斯特菌病相关的主要血清型。此外，所有分离株都含有内化素基因（inlA、inlC、inlJ），表明具有毒力潜力。这些分离株对所分析的大多数抗菌化合物敏感，有5株分离株（10%）具有多重耐药性。两株分离株携带抗菌药物耐药基因（tetM和ermB），其中一株的该基因存在于质粒中。此外，根据脉冲场凝胶电泳分析，两株多重耐药分离株是从食品和加工厂分离出的单个克隆。这些分离株对李斯特菌病治疗中最常用的抗生素敏感。然而，多重耐药分离株和抗菌药物耐药基因（包括质粒中的基因）的存在甚至可能在细菌物种之间转移，这表明对消费者存在潜在健康风险，以及多重耐药基因传播到其他细菌的潜在风险。
单核细胞增生李斯特菌是食源性疾病的重要病原体。本研究结果表明，从食品和食品环境中分离出的单核细胞增生李斯特菌分离株具有导致人类感染的潜在能力。检测到10%的菌株具有抗菌多重耐药性谱，两株分离株携带tetM和ermB耐药基因。此外，本研究有助于更好地了解单核细胞增生李斯特菌的抗菌药物耐药性。此外，我们发现一株携带tetM耐药基因的分离株存在于质粒中，这表明食品环境中的共生菌和/或其他病原菌之间可能存在传播，从而引发了对细菌耐药性的担忧。
