Kuznetsova M V, Provorova S V, Kubarev O G, Yudin D S, Karimova N V, Bajandina N V, Teplyakova M A, Demakov V A
Institute of Ecology and Genetics of Microorganisms Ural Branch Russian Academy of Sciences, Perm, Russia.
Perm State National Research University, Perm, Russia.
Urologiia. 2018 Dec(6):37-44.
The etiological structure of urinary tract infections (UTI) is determined by the leading role of uropathogenic Escherichia coli (UPEC). The aim of the work is to study the biological properties and phylogenetic diversity of E. coli strains isolated from UTI in outpatient and inpatient patients.
s and materials. 198 clinical UPEC strains were studied, 105 of which were designated as polyclinic and 93 as nosocomial (73 are isolated from urine and 20 are from catheter surface 48 hours after hospitalization). UPEC phylogenetic groups were determined by polymerase chain reaction (quadruplex PCR) according to O. Clermont et al. (2013).
Among polyclinic cultures, representatives of all eight recognizable phylogroups were found; strains of UPEC phylogroup B2 (37.1%), E (13.3%) and F (8.6%) were most often found. Nosocomial cultures in almost 90% of cases belonged to the phylogroup B2, to which all the catheter-associated strains were assigned. The E. coli of the phylogroup B2, both in the mono-species and in the polymicrobial associations, was authentically more often isolated in the hospital than in the polyclinic (p<0.00001), whereas the bacteria of the phylogroup E, on the contrary, in the polyclinic (p<0.0001) . The hemolytic activity and biofilm-forming ability of UPEC strains did not differ in the two groups, while in the hospital hemolytic E. coli of the B2 phylogroup was significantly more likely than the polyclinic (p<0.001). In addition, B2 strainsformed biofilms in more than 60% cases. Regardless of the source of isolation, the strains were resistant to ampicillin (62.1%), amoxicillin/clavulanate (27.8%), cefotaxime (37.9%) and ciprofloxacin (36.9%). The production of ESBL was detected in fifty-one (25.8%) cultures, with a statistically significant difference in nosocomial strains: urinary<catheter-associated (p<0.005). There were no link between the production of ESBL and membership of the B2 phylogroup, although B2 isolates more often produced ESBL than representatives of other phylogroups.
The decrease in the sensitivity of community-acquired UPEC to beta-lactam antibiotics promotes the "convergence of the resistance phenotypes" in polyclinic and inpatient cultures. In the hospital under conditions of an immunocompromised host it is possible to concentrate E. coli B2 with a high virulent potential.
尿路感染（UTI）的病因结构由尿路致病性大肠杆菌（UPEC）的主导作用决定。这项工作的目的是研究从门诊和住院患者的UTI中分离出的大肠杆菌菌株的生物学特性和系统发育多样性。
方法和材料。研究了198株临床UPEC菌株，其中105株被指定为门诊菌株，93株为医院感染菌株（73株从尿液中分离，20株在住院48小时后从导管表面分离）。根据O. Clermont等人（2013年）的方法，通过聚合酶链反应（四重PCR）确定UPEC系统发育群。
在门诊培养物中，发现了所有八个可识别系统发育群的代表；最常发现的是UPEC系统发育群B2（37.1%）、E（13.3%）和F（8.6%）的菌株。在近90%的病例中，医院感染培养物属于系统发育群B2，所有与导管相关的菌株都属于该群。系统发育群B2的大肠杆菌，无论是在单菌种还是多菌种组合中，在医院中比在门诊更常被分离出来（p<0.00001），而相反，系统发育群E的细菌在门诊中更常被分离出来（p<0.0001）。两组中UPEC菌株的溶血活性和生物膜形成能力没有差异，而在医院中，B2系统发育群的溶血大肠杆菌比门诊更有可能出现（p<0.001）。此外，B2菌株在超过60% 的病例中形成生物膜。无论分离来源如何，这些菌株对氨苄西林（62.1%）、阿莫西林/克拉维酸（27.8%）、头孢噻肟（37.9%）和环丙沙星（36.9%）耐药。在51株（25.8%）培养物中检测到ESBL的产生，医院感染菌株有统计学上的显著差异：尿液 < 导管相关（p<0.005）。ESBL的产生与B2系统发育群的成员之间没有联系，尽管B2分离株比其他系统发育群的代表更常产生ESBL。
社区获得性UPEC对β-内酰胺类抗生素敏感性的降低促进了门诊和住院培养物中“耐药表型的趋同”。在医院免疫受损宿主的情况下，有可能聚集具有高毒力潜力的大肠杆菌B2。
