Occurrence of virulence genes, 16S rRNA methylases, and plasmid-mediated quinolone resistance genes in CTX-M-producing Escherichia coli from Pakistan

Abstract

The aim of the study was to conduct a comprehensive molecular characterization of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli collected from Pakistan. Genetic relatedness among 98 ESBL-producing E. coli was measured by pulsed-field gel electrophoresis (PFGE). The presence of genes encoding ESBLs, virulence factors (VFs), 16S rRNA methylases, plasmid-mediated quinolone resistance (PMQR) encoding elements, plasmid replicon types, phylogenetic groups of E. coli, prevalence of the worldwide disseminated clone E. coli ST131, and phylogrouping of CTX-M enzymes was investigated by polymerase chain reaction (PCR). All isolates carried bla CTX-M genes and, except for one isolate from CTX-M phylogroup 9, they all belonged to CTX-M phylogroup 1. The isolates were genetically diverse with PFGE. Phylogenetic group D (36 %) was most abundant in this collection of E. coli, whereas isolates belonging to B2 (22 %) had the highest content of virulence genes. PMQR genes were found in 84.6 % of the isolates; among them, 93 % isolates were positive for variants of acetyltransferases (aac(6')-lb-cr), whereas qnrB, qepA, and qnrS were present in 11 %, 5 %, and 4 % of the isolates, respectively. Only 3 % of the isolates contained genes encoding 16S rRNA methylases. The most abundant replicon type was IncF (96 %), and 18 % of the isolates belonged to the ST131 clone. Out of 34 investigated VFs, 24 genes encoding different types of adhesins, protectins, toxins, siderophores, and other VFs were found. Although the isolates in this collection were highly resistant to many antimicrobials, susceptibility to amikacin and meropenem was retained.

Escherichia coli ST131, an Intriguing Clonal Group

“…E. coli ST131 strains are mostly of serotype O25:H4, with a specific O25 type, O25b. However, ST131 E. coli isolates of serotype O16:H5 have recently been identified in Japan, Denmark, Australia, Spain, Pakistan, and France (18)(19)(20)(21)(22)(23)(24). Moreover, some E. coli ST131 isolates have been shown to be nontypeable for O or H antigens (18,25).…”

Strain Typing and Molecular Characterization of CTX-M-1 Group ESBL in Clinical Klebsiella pneumoniae Isolated from Children

“…A multicountry study reported that carbapenems are the treatment of choice for infections caused by ESBL-producing K. pneumoniae (26). Coresistance to several antimicrobial agents has often been described for CTX-M-producing isolates (27,28). These arrays of resistance genes confer a multidrug resistance phenotype that can be transferred horizontally (28).…”

“…Coresistance to several antimicrobial agents has often been described for CTX-M-producing isolates (27,28). These arrays of resistance genes confer a multidrug resistance phenotype that can be transferred horizontally (28). Integrons are mobile genetic elements that can be located either on a chromo-some or a plasmid and can integrate antibiotic resistance genes.…”

Antibacterial activity of Valeriana jatamansi against extended-spectrum β-lactamase producing Gramnegative bacteria causing urinary tract infections

“…Further exploration of antibacterial resistance of all ESBLs producing isolates against different antibacterial agents were done by using disc diffusion method [9]. Antibiotics used for disc diffusion method were amikacin (30 μg), colistin sulphate (10 μg), fosfomycin (50 μg), ciprofloxacin (10 μg), ceftazidime (30 μg), cefotaxime (30 μg), gentamicin (10 μg), imipenem (10 μg), nalidixic acid (30 μg), piperacillin-tazobactam (100 μg + 10 μg), trimethoprimsulfamethoxazole (1.25 μg + 23.75 μg) and ticarcillin-clavulanic acid (75 μg + 10 μg).…”

“…Rapid emergence of ESBLs producing E. coli has been reported in a recent study from Pakistan [9]. Acquisition of multidrug resistance to commonly prescribed drugs leads scientists to introduce alternatives of these drugs that could be more potent for treatment of such infections and pathogens.Plants produce many secondary metabolites that have been familiar for biological activities [10].…”