Genomic Analysis of Ciprofloxacin-Resistant Serovar Kentucky ST198 From Spanish Hospitals.

serovar Kentucky (. Kentucky) with sequence type (ST) 198 and highly resistant to ciprofloxacin (ST198-Cip ) has emerged as a global MDR clone, posing a threat to public health. In the present study, whole genome sequencing (WGS) was applied to characterize all Cip Kentucky detected in five Spanish hospitals during 2009-2018. All Cip isolates ( = 13) were ST198 and carried point mutations in the quinolone resistance-determining regions (QRDRs) of both (resulting in Ser83Phe and Asp87Gly, Asp87Asn, or Asp87Tyr substitutions in GyrA) and (with Thr57Ser and Ser80Ile substitutions in ParC). Resistances to other antibiotics (ampicillin, chloramphenicol, gentamicin, streptomycin, sulfonamides, and tetracycline), mediated by the , , , , , and (A) genes, and arranged in different combinations, were also observed. Analysis of the genetic environment of the latter resistance genes revealed the presence of multiple variants of SGI1 ( genomic island 1)-K and SGI1-P, where all these resistance genes except were placed. IS elements, found at multiple locations within the SGI1 variants, have probably played a crucial role in their generation. Despite the wide diversity of SGI1-K- and SGI1-P-like structures, phylogenetic analysis revealed a close relationship between isolates from different hospitals, which were separated by a minimum of two and a maximum of 160 single nucleotide polymorphisms. Considering that isolates resistant to fluoroquinolones belong to the high priority list of antibiotic-resistant bacteria compiled by the World Health Organization, continuous surveillance of the . Kentucky ST198-CIP clone is required.