In:
Chemotherapy, S. Karger AG, Vol. 51, No. 6 ( 2005), p. 300-304
Abstract:
〈 i 〉 Background: 〈 /i 〉 Borderline methicillin resistance in 〈 i 〉 Staphylococcus aureus 〈 /i 〉 is due to β-lactamase overproduction and/or specific methicillinases. 〈 i 〉 Methods: 〈 /i 〉 β-Lactamase activity in culture supernatants and in cytoplasmic membrane fractions was estimated by bioassay and by SDS-PAGE combined with nitrocefin assay. 〈 i 〉 Results: 〈 /i 〉 During the investigation of borderline methicillin-resistant 〈 i 〉 Staphylococcus aureus 〈 /i 〉 (BORSA) strains VU94 and 822 two β-lactamases were detected in the membranes, with molecular weights of 13 and 30 kDa. The latter could be found in the culture supernatants, too. In the presence of globomycin, this enzyme disappeared from the membrane, and the oxacillin-hydrolyzing activity of the membrane decreased to the level of susceptible strains. Both β-lactamases were detected in the methicillin-resistant 〈 i 〉 Staphylococcus aureus 〈 /i 〉 strain studied, but the susceptible strains possessed only the first enzyme. 〈 i 〉 Conclusions: 〈 /i 〉 The 30-kDa β-lactamase proved to be a methicillinase, and it can be one of the main causes of the borderline phenotype of BORSA strains. The other enzyme is one of the smallest β-lactamases published to date.
Type of Medium:
Online Resource
ISSN:
0009-3157
,
1421-9794
Language:
English
Publisher:
S. Karger AG
Publication Date:
2005
detail.hit.zdb_id:
1482111-4
SSG:
15,3
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