The phylogenetic classification of Escherichia coli isolates is of great importance not only for understanding the populations of E. coli but also for clarifying the relationship between strains and diseases. The present study aimed to evaluate the prevalence of phylogenetic groups, antibiotic susceptibility pattern, and virulence genes among uropathogenic E. coli (UPEC) isolated from different parts of Iran through a systematic review and meta-analysis. Several international electronic sources, including Web of Science, PubMed, Scopus, and Embase, were searched (2000–2020) in order to identify the studies compatible with our inclusion criteria. The meta-analysis was performed using the metaprop program in the STATA (version 11) software. Based on our comprehensive search, 28 studies meeting the eligibility criteria were included in the meta-analysis. The pooled prevalence of phylogroups B2, D, B1, and A was 39%, 26%, 18%, and 8%, respectively. In addition, there was a significant heterogeneity among different phylogroups. However, according to the results of Begg’s and Egger’s tests, there were no significant publication bias in phylogroups B2, D, B1, and A. This research provided the first comprehensive study on phylogroups of UPEC isolated in Iran. Our findings indicated that phylogroup B2 and group D were the most predominant phylogenetic groups among UPEC isolates in various regions of Iran. In addition, we observed that certain phylogenetic groups are more antibiotic resistant than the others. It was also observed that the dissemination of virulent phylogroup B2 and D should be controlled via comprehensive infection control measures. Additionally, certain strategies should be developed for monitoring the antibiotic therapy.

Phylogenetic Group Distribution of Uropathogenic Escherichia coli and Related Antimicrobial Resistance Pattern: A Meta-Analysis and Systematic Review

Introduction Urinary tract infection (UTI) is one of the most frequent infections in kidney transplant patients (KTPs). This infection is mainly caused by uropathogenic Escherichia coli (UPEC). Plasmid-mediated quinolone resistance (PMQR) was also increasingly identified in UPEC. This study proposed to investigate the frequency of quinolone-resistance plasmid genes and the O-antigen serogroup among UPEC isolated from KTPs and non-KTP with UTI. Methods Totally, 114 UPEC isolates from 49 KTPs and 65 non-KTPs patients diagnosed with an UPEC-associated UTI were obtained from June 2019 to December 2019 at three laboratory centers in Isfahan, Iran. The isolates were confirmed through phenotypic and genotypic methods. Moreover, the antimicrobial susceptibility test to nalidixic acid, ciprofloxacin, norfloxacin, and ofloxacin was performed using a disk diffusion method. The presence of the qnr gene as well as the serogroup distribution was identified using the PCR method. Result According to data, the distribution of O1, O2, O4, O16, and O25 serogroups were 3.5%, 2.6, 3.5, 3.5, and 20.2%, respectively. Antibiotic susceptibility pattern revealed that the highest and lowest resistance rates were to nalidixic acid (69.3%) and norfloxacin (43.9%), respectively. Also, the frequency of qnrS and qnrB genes were 33.3% and 15.8%, respectively, while none of the isolates was found to be positive for the qnrA gene. There was no significant association between the presence of qnr genes and higher antibiotic resistance. Conclusion This study recognized that the qnrS gene, O25 serotype, and resistance to nalidixic acid had the highest frequencies in UPEC strains isolated from UTI patients.

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Characterization of Plasmid-Mediated Quinolone Resistance and Serogroup Distributions of Uropathogenic Escherichia coli among Iranian Kidney Transplant Patients

The rapid emergence of multidrug-resistant (MDR) bacteria indisputably constitutes a major global health problem. Pathogenic Escherichia coli are listed among the most critical group of bacteria that require fast development of new antibiotics and innovative treatment strategies. Among harmful extraintestinal Enterobacteriaceae strains, uropathogenic E. coli (UPEC) pose a significant health threat. UPEC are considered the major causative factor of urinary tract infection (UTI), the second-most commonly diagnosed infectious disease in humans worldwide. UTI treatment places a substantial financial burden on healthcare systems. Most importantly, the misuse of antibiotics during treatment has caused selection of strains with the ability to acquire MDR via miscellaneous mechanisms resulting in gaining resistance against many commonly prescribed antibiotics like ampicillin, gentamicin, cotrimoxazole and quinolones. Mobile genetic elements (MGEs) such as transposons, integrons and conjugative plasmids are the major drivers in spreading resistance genes in UPEC. The co-occurrence of various bacterial evasion strategies involving MGEs and the SOS stress response system requires further research and can potentially lead to the discovery of new, much-awaited therapeutic targets. Here, we analyzed and summarized recent discoveries regarding the role, mechanisms, and perspectives of MDR in the pathogenicity of UPEC.

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Molecular Factors and Mechanisms Driving Multidrug Resistance in Uropathogenic Escherichia coli—An Update

This study aimed to identify metallo-β-lactamases (MBLs) and AmpC β-lactamases-producing Escherichia coli isolates obtained from hemodialysis (HD) patients with urinary tract infections (UTI). A total of 257 HD patients with UTI were included in this study, from which 47 E. coli isolates were collected. Antibiotic susceptibility was tested by disc diffusion method. MBLs and AmpC production were phenotypically detected by imipenem-ethylenediaminetetracetate and cefoxitin/boronic acid assays, respectively. The presence of MBLs and AmpC genes was examined by polymerase chain reaction (PCR). Fosfomycin and ampicillin were the most and the least effective antibiotics against E. coli isolates, respectively. Moreover, 61.7% (29/47) of E. coli isolates were multidrug-resistant with seven different antibiotypes. Antibiotype V (AMP–CIP–IMP–MEM–CPD–CRO–CTX–GEN–LEV–SXT–TOB) was the most prevalent profile. Besides, 24 (51.1%) isolates were simultaneously resistant to imipenem and meropenem. Phenotypic assay showed MBL production in 16 (66.7%) of the 24 carbapenem-resistant E. coli isolates. The distribution of MBL genes in carbapenem-resistant E. coli was as follows: blaIMP 18 (72%), blaVIM 7 (28%), and blaNDM 1 (4%). AmpC was detected in 61.7% (29/47) of the isolates using the phenotypic method. The presence of AmpC genes was confirmed by PCR in only 26 of 29 (86.7%) AmpC producers. The frequencies of blaDHA-1, blaACC, and blaCMY-2 were 6 (20.7%), 11 (37.9%), and 21 (72.4%), respectively. The emergence of MBL and AmpC coproducing E. coli isolates calls for an urgent surveillance program for timely diagnosis and screening of these genes in our healthcare systems.

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Identification of metallo-β-lactamases and AmpC production among Escherichia coli strains isolated from hemodialysis patients with urinary tract infection

Background: The O-antigen is one of the uropathogenic Escherichia coli (UPEC) virulence factors used as a biomarker to classify E. coli strains. Objectives: In this study, the relationship between antibiotic resistance patterns and O-serogroups was investigated in UPEC strains isolated from patients with urinary tract infections (UTIs) in southern Iraq. Methods: A total of 100 UPEC isolates from the urine specimens of patients with UTIs within the age range of 4 months to 78 years in various southern Iraqi hospitals were collected (May 2017 to January 2018) and confirmed using biochemical tests (e.g., Analytical Profile Index 20E). Antibiotic susceptibility tests were performed using the disk diffusion method according to the Clinical and Laboratory Standards Institute guidelines. The multiple polymerase chain reaction technique was applied to investigate the prevalence of O-serogroups. Results: The most frequent serogroups in the E. coli isolates were O8 (27.7%) and O25 (24.4%); however, serogroup O83 was not observed in the samples. Serogroups O75, O6, O16, and O18 had the lowest frequency (1.1%) among the examined isolates. Furthermore, 10% of the isolates did not belong to any of the examined serogroups. The phenotypic tests showed that the highest and the lowest resistance belonged to piperacillin (92%) and imipenem (5%), respectively. Serogroups O4 and O21 showed the highest drug resistance; nevertheless, serogroups O75, O18, and O1 showed the lowest drug resistance. Additionally, 94% of the isolates were resistant to three or more classes of antibiotics. Conclusions: According to the results, UPEC isolates showed high resistance to common antibiotics; however, they were sensitive to imipenem and amikacin. Serogroups O8 and O25 were the most common among UPEC isolates. Moreover, O4 and O21 showed the highest drug resistance. There was a direct relationship between antimicrobial resistance and O-serogroups in UPEC isolates.

Amin Sadeghi

Papers

Characterization of Plasmid-Mediated Quinolone Resistance and Serogroup Distributions of Uropathogenic Escherichia coli among Iranian Kidney Transplant Patients

High frequency of integrons and efflux pump in Uropathogenic Escherichia coli isolated from Iranian kidney and non-kidney transplant patients