Characteristics of Escherichia coli Sequence Type 131 Isolates That Produce Extended-Spectrum β-Lactamases: Global Distribution of theH30-Rx Sublineage

Abstract

ABSTRACTWe designed a study to describe the characteristics of sequence type 131 (ST131) lineages, including theH30-Rx sublineage, among a global collection of extended-spectrum β-lactamase (ESBL)-producingEscherichia coliisolates from 9 countries collected from 2000 to 2011. A total of 240 nonrepeat isolates from Canada, the United States, Brazil, the Netherlands, France, the United Arab Emirates (UAE), India, South Africa, and New Zealand were included. Established PCR, sequencing, and typing methods were used to define ST131 lineages,H30 andH30-Rx phylogenetic groups,gyrAandparCmutations, virotypes, and plasmid-mediated quinolone resistance determinants. The majority of the isolates produced CTX-M-15 withaac(6′)-lb-cr, belonged to phylogenetic group B2, and were positive for theH30 lineage with thegyrA1ABandparC1aABmutations. ST131 showed 15 distinct pulsotypes; 43% of the isolates belonged to four pulsotypes, with a global distribution. Seventy-five percent of the ST131 isolates belonged toH30-Rx; this sublineage was present in all the countries and was associated with multidrug resistance,blaCTX-M-15,aac(6′)-lb-cr, and virotypes A and C. TheH41 lineage was negative for the ST131pabBallele-specific PCR. The multidrug-resistantH30-Rx sublineage poses an important public health threat due to its global distribution, association with virotype C, and high prevalence among ST131 isolates that produce CTX-M-15.