Molecular epidemiology of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae isolates in a district hospital in Taiwan.
Thirty-one of 104 clinical isolates of Klebsiella pneumoniae collected over a period of 8 months were found to be putative extended-spectrum beta-lactamase (ESBL) producers. Isoelectric focusing and an iodine overlay agar method were used for preliminary identification of the ESBLs. They were further identified by DNA sequencing. Seventy-one percent of the isolates were found to produce SHV-5. The variation in the ESBL patterns of these isolates was slight, with only five patterns being identified. The strains were typed by pulsed-field gel electrophoresis (PFGE), and 16 different genotypes were identified. When the PFGE patterns were analyzed by the algorithmic clustering method called the unweighted-pair group method using arithmetic averages, five clusters were found. However, significant genetic variations were found among 11 isolates and between each cluster. A plasmid of 36 kb was found in all clinical isolates and in the transconjugants. Our results indicate that the increase in the number of ESBL-producing K. pneumoniae isolates in this hospital is due mainly to the dissemination of a resistance plasmid rather than to the clonal spread of a few epidemic strains.
Liu
P Y
PY
Department of Internal Medicine, Shalu Tungs' Memorial Hospital, Shalu, Taiwan, Republic of China. liu712@top2.ficnet.net.tw
Tung
J C
JC
Ke
S C
SC
Chen
S L
SL
D002442:Ceftazidime; D018550:Cephalosporin Resistance; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D005838:Genotype; D006767:Hospitals, District; D006801:Humans; D007710:Klebsiella Infections / Q000453:epidemiology*; D007711:Klebsiella pneumoniae / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D017720:Molecular Epidemiology; D010802:Phylogeny; D013624:Taiwan / Q000453:epidemiology; D001618:beta-Lactamases / Q000096:biosynthesis*
D004269:DNA, Bacterial; D002442:Ceftazidime; D001618:beta-Lactamases