Prevalence of ST131 Clone Producing Both ESBL CTX-M-15 and AAC(6')Ib-cr Among Ciprofloxacin-Resistant Isolates from Yemen.

The aim of this study was to characterize the O25b/ST131 clone in ciprofloxacin-resistant isolates from Yemen. A total of 41 ciprofloxacin-resistant strains were collected from clinical samples of inpatients and outpatients from Sana'a (Yemen) from January to December 2013. Antimicrobial susceptibility testing, polymerase chain reaction amplification, and sequencing were used for detection of plasmid-mediated quinolone resistance determinants, extended-spectrum beta-lactamases genes and mutations in the quinolone resistance-determining regions of the target genes and . Genetic relatedness of isolates was determined by pulsed-field gel electrophoresis (PFGE). O25b/ST131 clone detection was performed using polymerase chain reaction of O25b and allele 3 of the gene and by a multilocus sequence typing. All isolates contained the 'r gene associated with and genes in 63.4% and 12.2%, respectively. A rate of 36.6% (15/41) of O25b/ST131 isolates were identified belonging to the H30-Rx subclone producing both CTX-M-15 and Aac(6')Ib-cr enzymes and carrying two substitutions in GyrA (Ser83Leu/Asp87Asn) and two substitutions in ParC (Ser80Ile/Glu84Val). Most of them were uropathogenic unrelated isolates recovered from outpatients. This is the first report of a high prevalence of O25b/ST131 from Yemen.