Résumé
OBJECTIVE To study 6 kinds of aminoglycoside-modifying enzymes (AMEs) genes in Chryseobacterium spp isolates. METHODS The isolates were identified by API20NE Gram-negative identification cards,and the susceptibility of antimicrobial agents was detected by MIC kits ( bioM?rieux ) 6 AMEs genes of 2 strains of Chryseobacterium spp were measured by PCR,and verified by DNA sequencing and sequence analysis. RESULTS In the 2 strains,2 kinds of resistant genes [aac(6′)-Ⅱ and ant(2″)-Ⅰ] were positive,and 4 kinds genes of AMEs [aac (6′)-Ⅰb,aac(3)-Ⅱ,ant(3″)-Ⅰ and aac(3)-Ⅰ] were negative.The amplicons were purified,sequenced and analyzed with BLAST 2.0 and found to be identical to aac(6′)-Ⅱ and ant(2″)-Ⅰ. CONCLUSIONS There are AMEs in Chryseobacterium spp isolates. This is the first report on AMEs genes [coexistance of aac(6′)-Ⅱ and ant(2″)-Ⅰ] in Chryseobacterium spp.
Résumé
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.