Objectives Co-resistance to fluoroquinolones and β-lactams results in treatment complications for uropathogenic Escherichia coli (UPEC) infections. This study aimed to detect the coexistence and co-transmission of plasmid-mediated quinolone resistance (PMQR) and extended-spectrum β-lactamase (ESBL) genes in UPEC from Kolkata, India. Methods Escherichia coli was detected biochemically from culture-positive urine samples. Antimicrobial resistance and ESBL production were confirmed by disk diffusion assay. Transfer of PMQR and ESBL genes was performed using azide-resistant E. coli J53 as recipient. PCR was conducted to identify PMQR and ESBL genes, plasmid incompatibility types, insertion sequences, integrons and ERIC-PCR patterns. Results PMQR determinants were detected in 50.0% (35/70) of ciprofloxacin-resistant isolates, with ESBL production in 42.9% (15/35) and a β-lactamase inhibitor-resistant phenotype in 51.4% (18/35). The highest co-occurrence (37.1%; 13/35) and co-transmission of aac(6′)-Ib-cr with blaTEM, blaCTX-M and blaOXA was observed. Among the conjugal plasmids, replicon types FrepB/FrepB + F1 B were predominant, with rare incidences of A/C, N, X, I1, FIIS, L/M and H1. Distribution of integrons and ISEcp1 and IS26, either alone or in combination, irrespective of PMQR and ESBL gene types was observed. Discrete ERIC-PCR profiles indicated that acquisition of PMQR and ESBLs and their dissemination may be attributed to horizontal gene transfer. Conclusion This study demonstrates for the first time the risk of co-transmission of fluoroquinolone and β-lactam resistance amongst UPEC from Kolkata, posing a major public-health threat and limiting treatment options. Monitoring at the molecular level is necessary to design appropriate prescription policies to combat the alarming rise in drug resistance amongst these uropathogens.

Incidence and risk of co-transmission of plasmid-mediated quinolone resistance and extended-spectrum β-lactamase genes in fluoroquinolone-resistant uropathogenic Escherichia coli: a first study from Kolkata, India.

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

Mutant selection window of four quinolone antibiotics against clinical isolates of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis.

Background: Antibiotic resistance rates in E. coli are rapidly rising, especially with regard to fluoroquinolones. One of the mechanisms that lead to antibiotic resistance is efflux pumps. The aim of this study was phonotypic and genotypic analysis of efflux pump role in fluoroquinolones resistance of E. coli strains isolated from hospitalized patients in Kermanshah 2013. Materials and Methods: In this cross-sectional study, 100 isolates of E. coli were collected from hospitalized patients from Kermanshah. All isolates were identified by standard biochemical tests. The antimicrobial susceptibility patterns were determined by disk diffusion method according to CLSI guidelines. The presence of Efflux pump genes was determined by a PCR method. Results: The rates of resistance to Ceftazidime, Nalidixic Acid, Ciprofloxacin, Norfloxacin, Ofloxacin, Gentamicin, and Tetracycline were 73%, 67%, 55%, 54%, 45%, 38%, and 24%, respectively. According to the results of PCR test, of 100 E. coli isolates, 99% of isolates were positive for acrA, 98% for acrB, 95% for acrE, 98% for acrF, 94% for mdfA, 96% for norE, and 96% for tolC. Conclusion: In Strains with positive gene acrA, acrB, acrA, acrB, tolC, mdfA, norE, the presence of efflux pump inhibitor reduced the amount of resistance to antibiotics. So, efflux pumps are important in antibiotic resistance.

Phenotypic and Genotypic Efflux Pumps in Resistance to Fluoroquinolones in E.coli Isolated from Inpatients in Kermanshah Hospitals in 2013

Fluorochinolones are a class of broad-spectrum antimicrobials in the treatment of several infections, including those caused by Escherichia coli. Due to the increasing resistance of bacteria to antimicrobials, an understanding of fluoroquinolone resistance is important for infection control. The aim of this study was to determine susceptibility of clinical E. coli strains to fluoroquinolones and characterize their mechanisms of quinolone resistance. Totally, 79 non-duplicate clinical E. coli isolates included in this study were mainly from skin lesion -36 (45.6%) isolates; 54 (68.4%) isolates were assigned to phylogenetic B2 group. Resistance to ciprofloxacin was found in 20 isolates. In the quinolone resistance-determining region (QRDR) region of gyrA and parC, 4 types of point mutations were detected. Mutations in parC gene were found in all strains with gyrA mutations. Predominance of double mutation in codon 83 and 87 of gyrA (90%) and in codon 80 of parC (90%) was found. Moreover, plasmid-mediated quinolone resistance (PMRQ) determinants (qnrA or qnrB and/or aac(6')-Ib-cr) were present in 5 (25%) out of 20 fluoroquinolone-resistant isolates. Resistance to fluoroquinolones in all of the tested clinical E. coli isolates correlated with point mutations in both gyrA and parC. The majority of fluoroquinolone-resistant strains belonged to D and B2 phylogenetic groups.

Kinga Skrzypek

Papers

Fluoroquinolone-resistance mechanisms and phylogenetic background of clinical Escherichia coli strains isolated in south-east Poland.