Characterization of antibiotic-susceptibility patterns and virulence genes of five major sequence types of Escherichia coli isolates cultured from extraintestinal specimens: a 1-year surveillance study from Iran

• Published in: Infection and drug resistance 2019-04, Vol.12, p.893-903
• Main Authors: Hojabri, Zoya, Mirmohammadkhani, Majid, Darabi, Narges, Arab, Maedeh, Pajand, Omid
• Format: Article
• Language: English
• Subjects: Antibiotics; Antimicrobial agents; carbapenem; Characterization; Cloning; Comparative analysis; Disease susceptibility; Drug resistance; E coli; Epidemiology; Escherichia coli; ExPEC; Genes; Genetic aspects; Genetic research; Health aspects; Hospitals; Imipenem; Infection; Laboratories; Meropenem; Original Research; Pandemics; PCoA; Phenotypes; Phylogeny; phylogroup; ST131; Sulfamethoxazole; Surveillance; Trimethoprim; UPEC; Urinary tract diseases; Urinary tract infections; Urine; Urogenital system; Virulence; Virulence (Microbiology)
• ISSN: 1178-6973; 1178-6973
• DOI: 10.2147/IDR.S199759

sequence types (STs) 69, 73, 95, 127, and 131 are major STs frequently causing extraintestinal infections. The prevalence of specific clones and their virulence and resistance profiles has not been described from Iran. The aim of this study was to characterize antimicrobial-susceptibility profiles and virulence traits of five major clones of recovered from human extraintestinal infections in Semnan, Iran. We compared these traits between major ST clones and also between O25b and O16 subgroups of the ST131 clone. We characterized the five major ST clones among 335 collected isolates obtained from extraintestinal infections, and phylogenetic groups, antimicrobial susceptibility, and virulence/resistance-gene profiles of these major STs were studied. The highest rates of the multidrug-resistance phenotype were detected among ST131 (85.7%) and ST69 (41.7%), and trimethoprim/sulfamethoxazole resistance was detected significantly among the latter clone. Of the 151 isolates belonging to major ST clones, was detected among all except the ST127 clone, while genes were harbored by 14 (9.2%) isolates, which all belonged to the ST131 clone. Aggregate virulence scores (median) of ST131 isolates (11) were slightly higher than ST69 (8.50) strains, but were lower than ST73 (16), ST95 (16), and ST127 (12.50) isolates. Principal-coordinate analysis revealed distinct virulence profiles with the ST131 clone. ST73, ST95 and ST131 were enriched with "urovirulence" traits, including phylogroup B2 and group B2-associated accessory traits ( , , , , , and ) and the derived variables extraintestinal pathogenic and uropathogenic . In contrast, ST69 was depleted of these traits, but enriched with phylogroups D and E. Our data emphasize that isolates of the ST131 clone have the ability to make a balance between resistance and virulence traits to establish a wider clone in extraintestinal pathogenic .