Predominance of IncL/M and IncF plasmid types among CTX-M-ESBL-producing Escherichia coli and Klebsiella pneumoniae in Bulgarian hospitals.

Our objective was to investigate the plasmid replicon-types involved in spread of ESBLs among Bulgarian Klebsiella pneumoniae and Escherichia coli. Sixty-three isolates, with transferable beta-lactam resistance determinants, collected between 2007 and 2009 in six medical institutions, were analysed with respect to their antimicrobial susceptibility, ESBL-, RAPD-, and plasmid replicon-type. Phylogenetic typing and screening for the O25b-ST131 lineage were carried out for E. coli. The predominant ESBLs were CTX-M-15 (81%) among E. coli and CTX-M-3 (58%) among K. pneumoniae. Other sporadically found ESBLs were SHV-12 and TEM-139, and for the first time in Bulgaria, CTX-M-1 and CTX-M-14. Replicon typing revealed that plasmids carrying blaCTX-M-3 exclusively belonged to IncL/M-type, while blaCTX-M-15 was predominantly (94%) associated with IncF-type plasmids. Among E. coli, 59% of the isolates were clonally related. Isolates of that cluster produced CTX-M-15, belonged to the O25b-ST131 lineage, predominantly harboured plasmids with the FIA replicon, and were found in five centres. Among CTX-M-3-producing K. pneumoniae, two prevailing RAPD-types were found, one remained restricted to one centre and the second was found in three centres. The incompatibility groups IncN and IncA/C linked with blaSHV-12 respectively blaTEM-139 were found only once. To the best of our knowledge, this is the first detailed investigation of plasmids carrying ESBL genes among Bulgarian isolates demonstrating wide distribution of conjugative IncF plasmids among CTX-M-15-producing E. coli and IncL/M plasmids among CTX-M-3 positive K. pneumoniae isolates.

Markovska R ，Schneider I ，Ivanova D ，Mitov I ，Bauernfeind A ... -  《-》

Replicon sequence typing of IncF plasmids and the genetic environments of blaCTX-M-15 indicate multiple acquisitions of blaCTX-M-15 in Escherichia coli and Klebsiella pneumoniae isolates from South Korea.

Shin J ，Choi MJ ，Ko KS 《-》

High prevalence of CTX-M-15-producing O25b-ST131 Escherichia coli clone in Bulgarian hospitals.

Markovska R ，Schneider I ，Ivanova D ，Keuleyan E ，Stoeva T ，Sredkova M ，Markova B ，Bojkova K ，Gergova R ，Bauernfeind A ，Mitov I ... -  《-》

Detection and molecular characterization of Escherichia coli CTX-M-15 and Klebsiella pneumoniae SHV-12 β-lactamases from bovine mastitis isolates in the United Kingdom.

Timofte D ，Maciuca IE ，Evans NJ ，Williams H ，Wattret A ，Fick JC ，Williams NJ ... -  《-》

Prevalence of acquired fosfomycin resistance among extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae clinical isolates in Korea and IS26-composite transposon surrounding fosA3.

Lee SY ，Park YJ ，Yu JK ，Jung S ，Kim Y ，Jeong SH ，Arakawa Y ... -  《-》