Nosocomial spread of armA-mediated high-level aminoglycoside resistance in Enterobacteriaceae isolates producing CTX-M-3 beta-lactamase in a cancer hospital in Bulgaria.
1,310 Enterobacteriaceae, 242 Pseudomonas aeruginosa and 97 Acinetobacter baumannii clinical isolates collected at a cancer hospital in Bulgaria were screened for the presence of 16S rRNA methylases. The armA methylase gene was identified in 20 (1.5%) Enterobacteriaceae (7 Klebsiella pneumoniae, 3 Escherichia coli, 3 Serratia marcescens, 3 Citrobacter freundii , 3 Enterobacter cloacae and 1 Klebsiella oxytoca). ArmA-mediated aminoglycoside resistance was transferable by conjugation and carried by closely related IncL/M plasmids which also carried ant3"9, dfrXII, sul1, bla(TEM-1), and bla(CTX-M-3) genes encoding resistance to streptomycin-spectinomycin, trimethoprim, sulfonamides, and ss-lactams, respectively. Most of the isolates were genetically different according to PFGE but shared similar restriction patterns of the armA -encoding plasmids. Our findings highlight the strong association of armA and bla(CTX-M-3) extended-spectrum ss-lactamase genes across various species in the family Enterobacteriaceae . The spread of multiresistant isolates expressing 16S rRNA methylases and ESBLs is a worrisome development requiring continuous monitoring.
Sabtcheva
S
S
Department of Infection Control and Laboratory Diagnostics, Tohoku Univeristy Graduate School of Medicine, Sendai, Japan. stefanasabtcheva@gmail.com
Saga
T
T
Kantardjiev
T
T
Ivanova
M
M
Ishii
Y
Y
Kaku
M
M
D000617:Aminoglycosides; D002031:Bulgaria; D002173:Cancer Care Facilities; D003428:Cross Infection / Q000453:epidemiology / Q000235:genetics*; D004352:Drug Resistance, Microbial / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field; D004755:Enterobacteriaceae / Q000235:genetics / Q000302:isolation & purification; D004756:Enterobacteriaceae Infections / Q000201:enzymology / Q000453:epidemiology / Q000235:genetics*; D006801:Humans; D008780:Methyltransferases / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D001618:beta-Lactamases / Q000378:metabolism*
D000617:Aminoglycosides; D012336:RNA, Ribosomal, 16S; D008780:Methyltransferases; C417271:beta-lactamase CTX-M-3; D001618:beta-Lactamases