title: Multiresistant uropathogenic Escherichia coli from a region in India where urinary tract infections are endemic: genotypic and phenotypic characteristics of sequence type 131 isolates of the CTX-M-15 extended-spectrum-β-lactamase-producing lineage.
abstract: Escherichia coli sequence type 131 (O25b:H4), associated with the CTX-M-15 extended-spectrum beta-lactamases (ESBLs) and linked predominantly to the community-onset antimicrobial-resistant infections, has globally emerged as a public health concern. However, scant attention is given to the understanding of the molecular epidemiology of these strains in high-burden countries such as India. Of the 100 clinical E. coli isolates obtained by us from a setting where urinary tract infections are endemic, 16 ST131 E. coli isolates were identified by multilocus sequence typing (MLST). Further, genotyping and phenotyping methods were employed to characterize their virulence and drug resistance patterns. All the 16 ST131 isolates harbored the CTX-M-15 gene, and half of them also carried TEM-1; 11 of these were positive for bla(OXA) groups 1 and 12 for aac(6')-Ib-cr. At least 12 isolates were refractory to four non-beta-lactam antibiotics: ciprofloxacin, gentamicin, sulfamethoxazole-trimethoprim, and tetracycline. Nine isolates carried the class 1 integron. Plasmid analysis indicated a large pool of up to six plasmids per strain with a mean of approximately three plasmids. Conjugation and PCR-based replicon typing (PBRT) revealed that the spread of resistance was associated with the FIA incompatibility group of plasmids. Pulsed-field gel electrophoresis (PFGE) and genotyping of the virulence genes showed a low level of diversity among these strains. The association of ESBL-encoding plasmid with virulence was demonstrated in transconjugants by serum assay. None of the 16 ST131 ESBL-producing E. coli strains were known to synthesize carbapenemase enzymes. In conclusion, our study reports a snapshot of the highly virulent/multiresistant clone ST131 of uropathogenic E. coli from India. This study suggests that the ST131 genotypes from this region are clonally evolved and are strongly associated with the CTX-M-15 enzyme, carry a high antibiotic resistance background, and have emerged as an important cause of community-acquired urinary tract infections.
authors.affiliation: Department of Biotechnology, University of Hyderabad, Hyderabad, India.
authors.forename: Arif
authors.initials: A
authors.lastname: Hussain
authors.forename: Christa
authors.initials: C
authors.lastname: Ewers
authors.forename: Nishant
authors.initials: N
authors.lastname: Nandanwar
authors.forename: Sebastian
authors.initials: S
authors.lastname: Guenther
authors.forename: Savita
authors.initials: S
authors.lastname: Jadhav
authors.forename: Lothar H
authors.initials: LH
authors.lastname: Wieler
authors.forename: Niyaz
authors.initials: N
authors.lastname: Ahmed
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000032:analysis / Q000378:metabolism; D015373:Bacterial Typing Techniques; D018441:Biofilms / Q000187:drug effects; D003227:Conjugation, Genetic; D004269:DNA, Bacterial / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D019353:Endemic Diseases; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000472:pathogenicity; D004927:Escherichia coli Infections / Q000382:microbiology*; D005838:Genotype; D007194:India / Q000453:epidemiology; D010641:Phenotype; D010957:Plasmids / Q000235:genetics; D016133:Polymerase Chain Reaction; D014552:Urinary Tract Infections / Q000382:microbiology*; D014774:Virulence / Q000235:genetics; D001618:beta-Lactamases / Q000032:analysis / Q000235:genetics* / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; C473109:beta-lactamase CTX-M-15; D001618:beta-Lactamases; C063912:carbapenemase