Miranda-Estrada Laura Iveth, Ruíz-Rosas María, Molina-López José, Parra-Rojas Isela, González-Villalobos Edgar, Castro-Alarcón Natividad
Unidad Académica de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Chilpancingo de los Bravo, Guerrero, México.
Laboratorio Clínico, Clínica Hospital ISSSTE, Chilpancingo de los Bravo, Guerrero, México.
Enferm Infecc Microbiol Clin. 2017 Aug-Sep;35(7):426-433. doi: 10.1016/j.eimc.2016.02.021. Epub 2016 Apr 3.
Escherichia coli is the major causative agent of urinary tract infections (UTI), and virulence factors are responsible for the severity of these emerging infections. The aim of this study was to evaluate the relationship between virulence determinants and antibiotic susceptibility with phylogenetic groups of E.coli isolates of UTI in two locations in Mexico.
An analysis was performed on 50 isolates of E.coli from the centre of the country and 57 from a town in the southwest. The isolates were characterized by phenotype (serotyping assays, in vitro adhesion, biofilm formation, production of haemolysin, and antibiotic susceptibility) and genotype (phylogenetic groups and virulence genes).
In the centre of the country location the phylogenetic group B2 (60%) and F (12%) were significantly more prevalent and had a higher frequency of genes, fimH (96%), iutA (66%), sat (36%), compared to the southwest location, where the group A (35%) and B1 (21%) were significantly predominant and had fewer virulence genes. About one-fifth (21.5%) of all isolates belonged to the O25-ST131 group. Haemolysin and biofilm producing strains were significantly higher in the southwest location. Resistance to ampicillin (92.5%), tetracycline (76.6%), and trimethoprim/sulfamethoxazole (70.1%) were the most common in both groups.
The phylogenetic group, virulence factors, and antibiotic susceptibility of the E.coli that causes UTI in the community, varies significantly among the Mexican populations studied. Phylogenetic groups A and B1 may be multidrug resistant and have the ability to produce UTI.
大肠杆菌是尿路感染（UTI）的主要病原体，毒力因子是这些新发感染严重程度的原因。本研究的目的是评估墨西哥两个地区尿路感染患者分离出的大肠杆菌毒力决定因素和抗生素敏感性与系统发育群之间的关系。
对来自该国中部的50株大肠杆菌和来自西南部一个城镇的57株大肠杆菌进行了分析。通过表型（血清分型检测、体外黏附、生物膜形成、溶血素产生和抗生素敏感性）和基因型（系统发育群和毒力基因）对分离株进行了鉴定。
在该国中部地区，系统发育群B2（60%）和F（12%）显著更为普遍，与西南部地区相比，其基因频率更高，fimH（96%）、iutA（66%）、sat（36%），在西南部地区，A群（35%）和B1群（21%）显著占主导地位，毒力基因较少。所有分离株中约五分之一（21.5%）属于O25-ST131群。西南部地区产生溶血素和生物膜的菌株显著更多。两组中对氨苄西林（92.5%）、四环素（76.6%）和甲氧苄啶/磺胺甲恶唑（70.1%）的耐药最为常见。
在墨西哥研究的人群中，引起社区获得性尿路感染的大肠杆菌的系统发育群、毒力因子和抗生素敏感性存在显著差异。系统发育群A和B1可能具有多重耐药性，并具有引起尿路感染的能力。
