Phylogenetic lineages, clones and ß-lactamases in an international collection of Klebsiella oxytoca isolates non-susceptible to expanded-spectrum cephalosporins.
J Antimicrob Chemother
; 70(12): 3230-7, 2015 Dec.
Article
em En
| MEDLINE
| ID: mdl-26318191
ABSTRACT
OBJECTIVES:
The objective of this study was to examine Klebsiella oxytoca clonal and phylogenetic diversity, based on an international collection of carriage isolates non-susceptible to expanded-spectrum cephalosporins (ESCs).METHODS:
The study material comprised 68 rectal carriage K. oxytoca isolates non-susceptible to ESCs recovered in 2008-11 from patients in 14 hospitals across Europe and Israel. ESC resistance was tested phenotypically; genes encoding ESBLs, AmpC cephalosporinases and carbapenemases were amplified and sequenced. The isolates were typed by PFGE and MLST, followed by sequencing of blaOXY genes.RESULTS:
MLST and PFGE distinguished 34 STs and 47 pulsotypes among the isolates, respectively. Six STs were split into several pulsotypes each. Five STs were more prevalent (nâ=â2-9) and occurred in several countries each, including ST2, ST9 and ST141, which belong to a growing international clonal complex (CC), CC2. Four phylogenetic lineages were distinguished, each with another type of chromosomal OXY-type ß-lactamase. Three of these, with OXY-1/-5, OXY-2 types and OXY-4, corresponded to previously described phylogroups KoI, KoII and KoIV, respectively. A single isolate from Israel represented a distinct lineage with a newly defined OXY-7 type. The phylogroups showed interesting differences in mechanisms of ESC resistance; KoI strains rarely overexpressed the OXY enzymes but commonly produced ESBLs, whereas KoII strains often were OXY hyperproducers and carried ESBLs much less frequently. AmpCs (DHA-1) and carbapenemases (VIM-1) occurred sporadically.CONCLUSIONS:
The study confirmed the high genetic diversity of the collection of K. oxytoca ESC-non-susceptible isolates, composed of phylogroups with distinct types of OXY-type ß-lactamases, and revealed some STs of broad geographical distribution.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Infecções por Klebsiella
/
Cefalosporinas
/
Resistência beta-Lactâmica
/
Klebsiella oxytoca
/
Genótipo
/
Antibacterianos
Limite:
Humans
País/Região como assunto:
Asia
/
Europa
Idioma:
En
Revista:
J Antimicrob Chemother
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
Polônia