RESUMO
The antibacterial activity of BK-218 was similar to that of cefamandole when it was tested against several laboratory strains. The inhibiting effect of BK-218 was greater than that of cephalexin and cefoxitin on penicillin-binding proteins of Escherichia coli HB101. This result was in close correlation with the relative inhibition of radiolabeled glucosamine incorporation (greatest with BK-218) and with the lytic effect (most intensive with BK-218). BK-218 proved to be a good inhibitor for all five of the beta-lactamases that were investigated, although two enzymes (Enterobacter cloacae P99 and Pseudomonas aeruginosa Cilote) hydrolyzed it to some extent.
Assuntos
Bactérias/efeitos dos fármacos , Proteínas de Bactérias , Cefalosporinas/farmacologia , Hexosiltransferases , Peptidil Transferases , Bactérias/metabolismo , Proteínas de Transporte/metabolismo , Parede Celular/metabolismo , Cefalosporinas/metabolismo , Cefalosporinas/farmacocinética , Citoplasma/metabolismo , Enterococcus faecalis/metabolismo , Escherichia coli/metabolismo , Glucosamina/metabolismo , Testes de Sensibilidade Microbiana , Muramilpentapeptídeo Carboxipeptidase/metabolismo , Proteínas de Ligação às Penicilinas , beta-Lactamases/metabolismoAssuntos
Antibacterianos/metabolismo , Staphylococcus aureus/enzimologia , beta-Lactamases/metabolismo , Antibacterianos/farmacologia , Cefalosporinas/farmacocinética , Cefalosporinas/farmacologia , Indução Enzimática/efeitos dos fármacos , Cinética , Testes de Sensibilidade Microbiana , Staphylococcus aureus/classificação , beta-Lactamases/biossínteseRESUMO
Although still there are Klebsiella strains which do not harbour plasmids and produce constitutive chromosomal beta-lactamases, recently clinical isolates were found in ever increasing numbers carrying mainly TEM-, CARB- and OXA type R-factors. We selected four chromosomal cephalosporinase producing Klebsiella strains to study the pI values of the enzymes and their simultaneous separability from accompanying proteins by chromatofocusing techniques. We compared pI values of the pure and the crude preparations: K. pneumoniae K1 SC 10436: pIpure = 6.4, pIcrude = 6.42; K. aerogenes K1 1082 E: pIpure = 6.5, pIcrude = 6.5; K. oxytoca 1082 E: pIpure = 6.42, pIcrude = 6.4; K. oxytoca 20: pIpure = 7.62, pIcrude = 7.6. Excellent agreement of the pI values among each other, but occasional differences with those obtained by analytical isoelectrofocusing are attributed to methodological diversities and to the presence of satellite enzymes, known to exist in Klebsiella.