title: Identification of extensive drug resistant Pseudomonas aeruginosa strains: New clone ST1725 and high-risk clone ST233.
abstract: Several microorganisms produce nosocomial infections (NIs), among which Pseudomonas aeruginosa stands out as an opportunist pathogen with the capacity to develop multiresistance to first-choice antibiotics. From 2007 to 2013, forty-six NIs produced by P. aeruginosa were detected at a pediatric tertiary care hospital in Mexico with a significant mortality rate (17.39%). All isolates (n = 58/46 patients) were characterized by evaluating their response to several antibiotics as panresistant (PDR), extensively resistant (XDR), multiresistant (MDR) or sensitive (S). In addition, all isolates were typified through multilocus sequencing of seven genes: acsA, aroE, guaA, mutL, nuoD, ppsA and trpE. Furthermore, to establish the genetic relationships among these isolates, we carried out a phylogenetic inference analysis using maximum likelihood to construct a phylogenetic network. To assess evolutionary parameters, recombination was evaluated using the PHI test, and the ratio of nonsynonymous to synonymous substitutions was determined. Two of the strains were PDR (ST1725); 42 were XDR; four were MDR; and ten were S. Twenty-one new sequence types were detected. Thirty-three strains exhibited novel sequence type ST1725. The ratio of nonsynonym to synonym substitutions was 1:1 considering all genes. Phylogenetic analysis showed that the genetic relationship of the PDR, XDR and MDR strains was mainly clonal; however, the PHI test and the phylogenetic network suggest that recombination events occurred to produce a non-clonal population. This study aimed not only to determine the genetic diversity of clinical P. aeruginosa but also to provide a warning regarding the identification and spreading of clone ST1725, its ability to cause outbreaks with high mortality rates, and to remain in the hospital environment for over seven years. These characteristics highlight the need to identify clonal outbreaks, especially where high resistance to most antibiotics is observed, and control measures are needed. This study also represents the first report of the PDR ST1725.
authors.affiliation: Posgrado en Ciencias Quimicobiológicas, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, México City, México.|Laboratorio de Infectología, Hospital Infantil de México Federico Gómez, México City, México.|Laboratorio de Variación Biológica y Evolución, Departamento de Zoología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, México City, México.
authors.forename: Pamela
authors.initials: P
authors.lastname: Aguilar-Rodea
authors.affiliation: Laboratorio de Variación Biológica y Evolución, Departamento de Zoología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, México City, México.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Zúñiga
authors.affiliation: Laboratorio de Investigación y Diagnóstico en Nefrología y Metabolismo Mineral Óseo, Hospital Infantil de México Federico Gómez, México City, México.
authors.forename: Benjamín Antonio
authors.initials: BA
authors.lastname: Rodríguez-Espino
authors.affiliation: Laboratorio de Infectología, Hospital Infantil de México Federico Gómez, México City, México.
authors.forename: Alma Lidia
authors.initials: AL
authors.lastname: Olivares Cervantes
authors.affiliation: Departamento de Infectología, Hospital Infantil de México Federico Gómez, México City, México.
authors.forename: Ana Estela
authors.initials: AE
authors.lastname: Gamiño Arroyo
authors.affiliation: Departamento de Infectología, Hospital Infantil de México Federico Gómez, México City, México.
authors.forename: Sarbelio
authors.initials: S
authors.lastname: Moreno-Espinosa
authors.affiliation: Departamento de Epidemiología, Hospital Infantil de México Federico Gómez, México City, México.
authors.forename: Daniela
authors.initials: D
authors.lastname: de la Rosa Zamboni
authors.affiliation: Subdirección de Servicios Auxiliares y de Laboratorio, Hospital Infantil de México Federico Gómez, México City, México.
authors.forename: Briceida
authors.initials: B
authors.lastname: López Martínez
authors.affiliation: Departamento de Laboratorio Clínico, Hospital Infantil de México Federico Gómez, México City, México.
authors.forename: María Del Carmen
authors.initials: MD
authors.lastname: Castellanos-Cruz
authors.affiliation: Departamento de Laboratorio Clínico, Hospital Infantil de México Federico Gómez, México City, México.
authors.forename: Israel
authors.initials: I
authors.lastname: Parra-Ortega
authors.affiliation: Laboratorio de Infectología, Hospital Infantil de México Federico Gómez, México City, México.
authors.forename: Verónica Leticia
authors.initials: VL
authors.lastname: Jiménez Rojas
authors.affiliation: Laboratorio de Infectología, Hospital Infantil de México Federico Gómez, México City, México.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Vigueras Galindo
authors.affiliation: Laboratorio de Infectología, Hospital Infantil de México Federico Gómez, México City, México.
authors.forename: Norma
authors.initials: N
authors.lastname: Velázquez-Guadarrama
mesh_terms: D024881:Drug Resistance, Bacterial / Q000235:genetics*; D005798:Genes, Bacterial; D008800:Mexico; D008826:Microbial Sensitivity Tests; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000235:genetics