Characterization of clinical isolates of beta-lactamase-negative, highly ampicillin-resistant Enterococcus faecalis.
We analyzed the penicillin-binding protein (PBP) profiles of two clinical isolates of Enterococcus faecalis for which ampicillin MICs were 32 and 64 micrograms/ml. Six PBPs were detected in both isolates, demonstrating an apparently increased amount of PBP 5 and decreased penicillin binding of PBPs 1 and 6. These results suggest that ampicillin resistance in the clinical isolates of E. faecalis described could be associated with alterations in different PBPs.
Servicio de Microbiología, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
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E
Cercenado
M F
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Vicente
M D
MD
Díaz
C
C
Sánchez-Carrillo
M
M
Sánchez-Rubiales
D000668:Ampicillin Resistance / Q000502:physiology*; D001426:Bacterial Proteins; D002352:Carrier Proteins / Q000378:metabolism; D013293:Enterococcus faecalis / Q000187:drug effects* / Q000201:enzymology*; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology*; D006602:Hexosyltransferases; D006801:Humans; D002267:Muramoylpentapeptide Carboxypeptidase / Q000378:metabolism; D046915:Penicillin-Binding Proteins; D010406:Penicillins / Q000378:metabolism; D010458:Peptidyl Transferases; D001618:beta-Lactamases / Q000378:metabolism*
D001426:Bacterial Proteins; D002352:Carrier Proteins; D046915:Penicillin-Binding Proteins; D010406:Penicillins; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase; D001618:beta-Lactamases