Drug Resistance and Detection of ?-Lactamase from Chryseobacterium spp:A Five Year Surveillance / 中华医院感染学杂志

ABSTRACT

OBJECTIVE To investigate the isolation and drug resistance of Chryseobacterium spp in our hospital,and to explore the mechanisms of drug resistance.METHODS Bacteria were identified in our hospital for the last five years(Jan 2001-Dec 2005) and the antimicrobial susceptibility was tested by Kirby-Bauer plate dilution method.Forty-three isolates of C.meningosepticum,16 isolates of C.indologenes and 10 isolates of C.gleum were isolated and selected for further studies.Minimum inhibitory concentrations(MICs) against 14 antibiotics were determined by the agar dilution method.Extended-spectrum ?-lactamase(ESBL) and carbapenemase were detected by three-dimensional test and 2-mercaptopropionic acid inhibitory test.RESULTS One thousand and one hundred twenty-eight Chryseobacterium and others strains in total were isolated during the described period.Among them C.meningosepticum,C.indologenes,C.gleum,and other Chryseobacterium species were 88.3%,8.0%,2.9%,0.6% and 0.2%,respectively.The resistant ratios against antibiotics containing enzyme inhibitors were lower than other antibiotics.The MIC50 and MIC90 against most antibiotics were high except for quinolones.As for carbapenemase,the positive rate was 60.5%,68.8% and 90.0% in C.meningosepticum,C.indologenes,and C.gleum,respectively.CONCLUSIONS Chryseobacterium are highly resistant against a variety numbers of antibiotics.Nevertheless,there exists a significant difference in the resistance against different antibiotics for different species of Chryseobacterium.The major drug resistant mechanism in Chryseobacterium is due to the production of ?-lactamases,especially metallo-?-lactamases.