Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0519030 (Klebsiella)
 21,988 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

CP-35,587 {6-[d-2-amino-2-(p-hydroxyphenyl)acetamido]-2,2-dimethyl-3- (5-tetrazolyl)-penam} is a member of a new family of beta-lactam antibacterial agents. Because the biospectrum of CP-35,587 has features similar to both penicillins and cephalosporins, experiments were carried out to explore its mode of action. CP-35,587 did not inhibit peptidoglycan transpeptidase from Escherichia coli, but it did inhibit dd-carboxypeptidase. Similar results were obtained with cephalexin. When these antibiotics were compared for effects on growth and morphology of E. coli, it was observed that filaments formed after exposure to either antibacterial agent for 30 to 60 min. The filaments enlarged, and fragmentation occurred until very few viable cells remained after exposure to CP-35,587. After 180 min in the presence of cephalexin, the cells began to divide, and the filaments formed cross-walls reaching control values in 24 h. CP-35,587 and cephalexin had similar effects on the morphology of the Klebsiella cell: the cells became enlarged within 30 min; with increasing exposure, the filaments became longer, with evidence of cytoplasmic emptying and ghost cell formation. These ghostlike tubules eventually broke apart, leaving fragments. These data indicate differences in the mode of action of CP-35,587 from those of most other beta-lactam antibiotics.
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PMID:Mode of action of a structurally novel beta-lactam. 68 5

MT-141, a new cephamycin (7 alpha-methoxy-cephalosporin) antibiotic with a D-cysteine moiety in its 7 beta-side chain, has binding affinities to penicillin-binding proteins of Escherichia coli and an inhibitory action on their transpeptidase activity similar to those of other structurally related cephamycins. Yet this antibiotic was found to exert an exceedingly strong and rapid lytic action on sensitive Gram-negative bacteria such as E. coli, Klebsiella pneumoniae, Serratia marcescens and Salmonella enteritidis. Not only rapidly growing cells, but also slowly growing dense cells of the above bacteria could be lysed by this antibiotic at low concentrations. In the presence of 20% sucrose, low concentrations of MT-141 induced smooth-surfaced single and twin bulges of the putative growth zone of the cells and irregularly orientated rough-surfaced bulges. Probably the 7 beta-side chain structure of this antibiotic is involved in its rapid and strong bacteriolytic action.
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PMID:The bacteriolytic action of MT-141, a new cephamycin antibiotic, on gram-negative bacteria. 392 Jan 78

Azthreonam (SQ 26,776) is a member of a new class of monocyclic beta-lactam antibiotics. In Escherichia coli, azthreonam caused filamentation at its lowest effective concentration (0.2 microgram/ml), a morphological effect identical to that observed with cephalothin. The penicillin-binding protein (PBP) profile indicated a very high affinity for PBP3 (complete binding at 0.1 microgram/ml), a moderate affinity for PBP1a (complete binding at 10 micrograms/ml), and poor affinities for PBP1b, PBP2, PBP4, and PBP5/6 (complete binding at greater than or equal to 100 micrograms/ml). Accordingly, azthreonam had poor activity against Streptomyces R61 DD-carboxypeptidase (50% inhibition, greater than 100 micrograms/ml) and E. coli peptidoglycan transpeptidase (50% inhibition, 100 micrograms/ml). Azthreonam also showed very high affinity for PBP3 (complete binding at 0.1 microgram/ml) in Proteus vulgaris, Enterobacter cloacae, Klebsiella pneumoniae, and Pseudomonas aeruginosa. In all four organisms, its PBP profile was similar to that observed in E. coli. It is concluded that azthreonam, although of novel structure, has a mode of action similar to that of cephalosporins, affecting specifically septation in E. coli and most likely other gram-negative bacteria.
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PMID:Mode of action of azthreonam. 618 Jun 85