LEVERSTEIN VAN HALL MA, PAAUW A, BOX AT, FLUIT A, VERHOEF J; Interscience Conference on Antimicrobial Agents and Chemotherapy (43rd: 2003: Chicago, Ill.).
Abstr Intersci Conf Antimicrob Agents Chemother Intersci Conf Antimicrob Agents Chemother. 2003 Sep 14-17; 43: abstract no. C2-49.
University Medical Center Utrecht, Utrecht, Netherlands.
BACKGROUND: ESBL have rarely been reported from The Netherlands. However, during a sudden increase in the occurrence of genotypically unrelated multidrug-resistant Enterobacteriaceae (78 isolates, 7 species, 54 pts) at a Univ Hospital, 59% of E. coli and Klebsiella spp. showed an ESBL phenotype. The aim of this study was to characterize the b-lactamases in these isolates. METHODS: Phenotypic investigations were performed by Etest ESBL and isoelectrofocusing (IEF). TEM-, SHV- and CTX-M genotypes were determined by DNA sequencing and AmpC-genotypes by specific PCRs. RESULTS: IEF revealed that the majority of isolates produced multiple b-lactamases. pI?s were indicative for TEM, SHV, CTX-M and/or AmpC enzymes. Sequencing of TEM genes revealed TEM-1 and 4 new TEM-type b-lactamases, containing 3 amino acid substitutions: Lys21Phe (F), Arg164His (H), and Thr265Met (M). These 5 variants comprised 2 non-ESBL variants, namely F and FM, and 2 tentative ESBL-variants, HM, and FHM. The wide dissemination of the FM, HM, and FHM variants could be partly explained by clonal spread and horizontal transfer. Sequencing of SHV genes identified SHV-1, SHV-2a, SHV-5, SHV-11 and 2 new LEN-type b-lactamases in 2 Klebsiella pneumoniae strains. One LEN-type contained 3 amino acid substitutions as compared to LEN-1: Val4Ile, Asn53Ser, and His278Gln and the other LEN-type contained 3 additional substitutions: Val22Ala, Tyr24Asp, and Val114Thr. In addition, CTX-M-9 ESBLs and transferable ACC-1 AmpC b-lactamases were identified. CONCLUSION: A wide variety of b-lactamases and ESBLs were detected, including several novel TEM- and LEN-type b-lactamases. For the first time CTX-M and transferable AmpC b-lactamases are reported from The Netherlands. In addition, circumstantial evidence was obtained for the hypothesis that ESBLs result from a dynamic evolution due to single-step mutations.
Publication Types:
Keywords:
- Amino Acid Substitution
- DNA Primers
- Disease Outbreaks
- Enterobacteriaceae
- Enterobacteriaceae Infections
- Klebsiella
- Klebsiella Infections
- Klebsiella pneumoniae
- Netherlands
- Polymerase Chain Reaction
- beta-Lactamases
Other ID:
UI: 102266252
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