Imipenem resistance in clinical isolates of Proteus mirabilis associated with alterations in penicillin-binding proteins.
Two strains of Proteus mirabilis, IpR1 and IpR2, resistant to both imipenem and mecillinam, but susceptible to other beta-lactams were isolated from blood cultures of patients who had been treated with imipenem. Strain IpR1 was isolated in the same sample as a P. mirabilis IpS1 which was susceptible to imipenem and mecillinam. Strains IpR1 and IpR2 did not produce a beta-lactamase and their outer membrane protein profiles were similar to those of IpS1 and P. mirabilis ATCC 29906. Electrophoretic profiles of penicillin-binding proteins (PBPs) showed a decrease in PBP 1A of strains IpR1 and IpR2 compared with IpS1 and ATCC 29906. Competition experiments revealed a decrease in affinity of PBP 2 for imipenem from strain IpR1. These findings suggest that imipenem resistance in P. mirabilis might result from altered PBPs, as reported for Acinetobacter baumanii and Pseudomonas aeruginosa.
Neuwirth
C
C
Laboratoire de Bactériologie, Hôpital Universitaire du Bocage, Dijon, France.
Siébor
E
E
Duez
J M
JM
Péchinot
A
A
Kazmierczak
A
A
D000560:Amdinocillin / Q000494:pharmacology; D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism; D001426:Bacterial Proteins; D002352:Carrier Proteins / Q000378:metabolism*; D004352:Drug Resistance, Microbial; D004591:Electrophoresis, Polyacrylamide Gel; D006602:Hexosyltransferases; D006801:Humans; D015378:Imipenem / Q000494:pharmacology*; D007525:Isoelectric Focusing; D002267:Muramoylpentapeptide Carboxypeptidase / Q000378:metabolism*; D010403:Penicillin Resistance; D046915:Penicillin-Binding Proteins; D010406:Penicillins / Q000494:pharmacology; D010458:Peptidyl Transferases; D011512:Proteus Infections / Q000382:microbiology; D011513:Proteus mirabilis / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D013845:Thienamycins / Q000494:pharmacology*; D001618:beta-Lactamases / Q000378:metabolism
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; D046915:Penicillin-Binding Proteins; D010406:Penicillins; D013845:Thienamycins; D015378:Imipenem; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase; D001618:beta-Lactamases; D000560:Amdinocillin