Molecular characterization of extended-spectrum beta-lactamases in Enterobacteriaceae from patients of two hospitals in Saxony, Germany.
Between January and September 2003, 39 isolates of the family Enterobacteriaceae with phenotypically positive Vitek 1 extended-spectrum beta-lactamase (ESBL) test results were collected, originating from patients of two hospitals in Saxony, Germany. Plasmid DNA was isolated and screened by PCR for the presence of genes encoding beta-lactamases of SHV, TEM and CTX-M types. To differentiate ESBL and non-ESBL among SHV and TEM genes, detailed analysis of PCR products was performed. Twenty-four strains carried SHV-2, SHV-5 or SHV-12 genes. In a further 11 strains a CTX-M gene was detected. The CTX-M genes could be affiliated to the CTX-M-1 and CTX-M-9 cluster by RFLP analysis. In the case of four Klebsiella oxytoca isolates, hyperproduction of the chromosomal beta-lactamase K1 was inferred, because genes of the above-mentioned types were not detected. The strains contained plasmid DNA between 45 and 160 kb in size. Common plasmid restriction patterns among SHV-5 producers provided evidence of horizontal spread. Twenty strains had a MIC for cefotaxime of <or=4 mg l-1, 18 strains had the same MIC for ceftazidime, and nine strains had this MIC of >4 mg l-1 for both antibiotics. The ESBL phenotypes often coincided with ciprofloxacin or gentamicin resistance.
Schmitt
Joachim
J
Institute of Medical Microbiology and Hygiene, Technical University of Dresden, Fetscherstrasse 72, Dresden, Germany.
Jacobs
Enno
E
Institute of Medical Microbiology and Hygiene, Technical University of Dresden, Fetscherstrasse 72, Dresden, Germany.
Schmidt
Herbert
H
Institute of Medical Microbiology and Hygiene, Technical University of Dresden, Fetscherstrasse 72, Dresden, Germany.
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics*; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D004755:Enterobacteriaceae / Q000187:drug effects / Q000201:enzymology* / Q000302:isolation & purification; D004756:Enterobacteriaceae Infections / Q000382:microbiology*; D005858:Germany; D006761:Hospitals; D006801:Humans; D008826:Microbial Sensitivity Tests; D010957:Plasmids / Q000235:genetics; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism*; D047090:beta-Lactams / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D047090:beta-Lactams; D001618:beta-Lactamases