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Objective To investigate the situation and change of antifungal resistance in clinical Candida and other fungal iso- lates from 5 hospitals in diverse geographic region of China.Methods Antimicrobial susceptibility testing of 8 000 fungat iso- lates collected during 2001 and 2005 were carried out with 25?g fluconazole disk and 1?g voriconazole disk using disk diffusion method as recommend by CLSI/NCCLS M44-A.Disk test plates were automatically read and results were recoded with the BIOMIC Image Analysis System.The equivalent MICs were automatically calculated by the BIOMIC System software.Results The proportion of Candida atbicans and non-Candida albicans (e.g.Candida glabrata) in the total fungal isolates did not change significantly from 2001 to 2005.The susceptibility rate of C.albicans to fluconazole and vorieonazole were stable during 2001 and 2005.However, the resistance to fluconazole and voriconazole increased variably in C.glabrata and other non-Can- dida albicans fungal isolates during the same period.Conclusions The voriconazole demonstrated higher activity against all yeast species in comparison with fluconazole.The increasing resistance to fluconazole and voriconazole in non C.albicans fungal isolates including C.glabruta suggests the importance of surveillance of fungal resistance in Candida isolates.
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Objective To investigate the importance of plasmid-mediated quinolone resistance in the development of quinolone resistance in clinical isolates of gram-negative bacteria.Methods A total of 541 consecutive clinical isolates of gram-negative ba- cilli resistant or intermediate to ciprofloxacin were screened for the qnrA gene by PCR.Conjugation experiments were carried out with azide-resistant E.coli J53 as a recipient.The aac(6')-Ib-cr gene was detected.The mutations in the quinolone-resist- ance-determining region (QRDR) of the gyrA and parC genes were identified in qnrA positive strains.Results qnrA was identi- fied in 7 of the 541 strains.Among the qnrA positive strains,5 were Enterobacter cloacae.No qnrA was detected in nonfer- menters.Quinolone resistance was transferred in 4 of 7 qnrA positive strains.Transconjugants had 12-to 125-fold increases in MIC of ciprofloxacin relative to that of the recipient.Seven strains contained qnrA with a nucleotide sequence identical to that originally reported.Two transconjugants with higher ciprofloxacin MICs contained aac(6')-Ib-cr gene.Mutations occurred in the QRDR of the gyrA and parC genes in 5 PCR-positive clinical strains.Conclusions Transferable plasmid-mediated quinolone resistance associated with qnrA is highly prevalent in clinical strains of Enterobacter spp.aac(6')-Ib-cr gene and mutations in the quinolone targets may co-exist with qnrA,which may contribute to the further increase of resistance to quinolones.
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Objective Study the production of the?-lactamases in eight pan-resistant citrobact- er freandi and their epidemic characteristics.Methods Modified Hodge test and EDTA-disk syner- gy test were used to screen Metallo-?-lactarnases,and isoelectric focusing to estimate the production of ESBLs and AmpC enzymes.ESBLs,AmpC,MBL genes were amplified and analyzed by PCR and DNA sequencing.Molecular epidemics were investigated by PFGE.Results All the 8 strains pro- duced TEM-1,CTX-M-14,4 of them at the same time producing CTX-M-3.No Plasmid mediated AmpC was found.Furthermore,a new subtype of MBL with one amino acid different from IMP-8 was de- tected.All the 8 strains belong to the same PFGE type.Conclusions Pan-drug-resistant citrobacter freundi produced more than one kind of?-lactamases.All these isolates were clonally related.