Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina (UNIFESP-EPM), Universidade Federal de São Paulo, Rua Botucatu, 862, 3° andar, CEP 04023-062, São Paulo, SP, Brazil.
Rua Prof. Enéas de Siqueira Neto, Universidade Santo Amaro (UNISA), 340 CEP 04829-300-São Paulo, SP, Brazil.
Pathog Dis. 2019 Mar 1;77(2). doi: 10.1093/femspd/ftz014.
Escherichia albertii are emerging enteropathogens, whose identification is difficult, as they share biochemical characteristics and some virulence-related genes with diarrheagenic Escherichia coli (DEC). Studies on phylogeny, phenotypic characteristics and potential virulence factors of human E. albertii strains are scarce. In this study, we identified by multiplex PCR five E. albertii among 106 strains isolated from diarrheic children in São Paulo, Brazil, which were previously classified as atypical enteropathogenic E. coli. All strains were investigated regarding their phylogeny, biochemical properties, virulence-related properties, antimicrobial resistance and presence of putative virulence-related genes. All strains belonged to different E. albertii lineages and adhered to and produced attaching and effacing lesions on HeLa cells. Three strains invaded Caco-2 cells, but did not persist intracellularly, and three formed biofilms on polystyrene surfaces. All strains were resistant to few antibiotics and only one carried a self-transmissible resistance plasmid. Finally, among 38 DEC and 18 extraintestinal pathogenic E. coli (ExPEC) virulence-related genes searched, six and three were detected, respectively, with paa and cdtB being found in all strains. Despite the limited number of strains, this study provided additional knowledge on human E. albertii virulence potential, showing that they share important virulence factors with DEC and ExPEC.
产酸克雷伯菌是新兴的肠道病原体，其鉴定较为困难，因为它们与致泻性大肠埃希菌（DEC）具有相似的生化特征和一些与毒力相关的基因。目前关于人类产酸克雷伯菌菌株的系统发育、表型特征和潜在毒力因子的研究还比较匮乏。本研究通过多重 PCR 从巴西圣保罗腹泻儿童中分离的 106 株菌中鉴定出 5 株产酸克雷伯菌，这些菌株先前被归类为非典型肠致病性大肠埃希菌。所有菌株均进行了系统发育、生化特性、与毒力相关特性、抗菌药物耐药性和潜在毒力相关基因的检测。所有菌株均属于不同的产酸克雷伯菌谱系，能黏附和形成黏附性和破坏细胞的病变，并侵袭 Caco-2 细胞，但不能在细胞内持续存在，还能在聚苯乙烯表面形成生物膜。所有菌株对少数抗生素具有耐药性，仅 1 株菌携带可自我转移的耐药质粒。最后，在所研究的 38 株 DEC 和 18 株肠外致病性大肠埃希菌（ExPEC）的 38 个和 18 个与毒力相关的基因中，分别检测到 6 个和 3 个，所有菌株均携带 paa 和 cdtB 基因。尽管菌株数量有限，但本研究为人类产酸克雷伯菌的毒力潜能提供了更多的认识，表明它们与 DEC 和 ExPEC 具有重要的毒力因子。
