Deciphering the Resistome of the Widespread Pseudomonas aeruginosa Sequence Type 175 International High-Risk Clone through Whole-Genome Sequencing
Por:
Cabot G, López-Causapé C, Ocampo-Sosa AA, Sommer LM, Domínguez MÁ, Zamorano L, Juan C, Tubau F, Rodríguez C, Moyà B, Peña C, Martínez-Martínez L, Plesiat P and Oliver A
Publicada:
1 dic 2016
Resumen:
Whole-genome sequencing (WGS) was used for the characterization of the
frequently extensively drug resistant (XDR) Pseudomonas aeruginosa
sequence type 175 (ST175) high-risk clone. A total of 18 ST175 isolates
recovered from 8 different Spanish hospitals were analyzed; 4 isolates
from 4 different French hospitals were included for comparison. The
typical resistance profile of ST175 included penicillins,
cephalosporins, monobactams, carbapenems, aminoglycosides, and
fluoroquinolones. In the phylogenetic analysis, the four French isolates
clustered together with two isolates from one of the Spanish regions.
Sequence variation was analyzed for 146 chromosomal genes related to
antimicrobial resistance, and horizontally acquired genes were explored
using online databases. The resistome of ST175 was determined mainly by
mutational events; resistance traits common to all or nearly all of the
strains included specific ampR mutations leading to ampC overexpression,
specific mutations in oprD conferring carbapenem resistance, or a mexZ
mutation leading to MexXY overexpression. All isolates additionally
harbored an aadB gene conferring gentamicin and tobramycin resistance.
Several other resistance traits were specific to certain geographic
areas, such as a streptomycin resistance gene, aadA13, detected in all
four isolates from France and in the two isolates from the Cantabria
region and a glpT mutation conferring fosfomycin resistance, detected in
all but these six isolates. Finally, several unique resistance mutations
were detected in single isolates; particularly interesting were those in
genes encoding penicillin-binding proteins (PBP1A, PBP3, and PBP4).
Thus, these results provide information valuable for understanding the
genetic basis of resistance and the dynamics of the dissemination and
evolution of high-risk clones.
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