The cephalosporin fl-lactamase (cephalosporinase) produced by Acinetobacter was studied. The enzyme was partially purified by means of column chromatography and its properties were investigated. The enzyme was induced by benzylpenicillin, 6-aminopenicillanic acid and cephaloridine. Its molecular weight is 30,000, its optimal temperature 40°C, and its optimal pH 7.25-.7.50. Substrate specificity...

Cephalosporinase activity was demonstrated in all of 10 strains of Bacteroides fragilis investigated. Low rates of hydrolysis of cephalosporins (0.25 to 3.5 mumol of cephaloridine per h per 10(9) cells) were found, but no activity against penicillin substrates was detected. In two strains the cephalosporinase activity was increased 40-and 80-fold by growing cells in the presence of penicillin. ...

Cefoxitin resistance in Klebsiella pneumoniae from Escherichia coli strains isolated in Greek hospitals was found to be due to the acquisition of similar plasmids coding for group 1 beta-lactamases. The plasmids were not self-transferable but were mobilized by conjugative plasmids. These elements have also been spread to Enterobacter aerogenes. The most common enzyme was a Citrobacter freundii-...

With numerous imipenem-resistant clinical isolates of Pseudomonas aeruginosa as well as in vitro-selected resistant mutants, we have demonstrated, by a simple method with a powerful cephalosporinase inhibitor, BRL42715, the contribution of chromosomal cephalosporinase in resistance to imipenem in this species.

The first examples of an amido-distibene, L(†)Sb[double bond, length as m-dash]SbL(†) (L(†) = -N(Ar(†))(SiPr(i)3), Ar(†) = C6H2{C(H)Ph2}2Pr(i)-2,6,4), and a boryl dibismuthene, {(DAB)B}Bi[double bond, length as m-dash]Bi{B(DAB)} (DAB = {(C6H3Pr(i)2-2,6)NCH}2, have been prepared by reaction of a lithium boryl complex, (THF)2LiB(DAB), with extremely bulky amido-group 15 dihalide precursor compoun...

A novel carbapenem, SF2103A, is a strong inhibitor of various types of 3-lactamase. Equimolar concentrations of SF2103A completely inactivated the cephalosporinases of Proteus vulgaris and Citrobacter freundii and type lb and type II penicillinases mediated by R plasmids in a progressive manner. The inactivation of the two penicillinases and P. vulgaris cephalosporinase was apparently irreversi...

Cefclidin (E1040), which has an aminothiadiazolyl group in the 7 beta-side chain, showed about four-fold higher activity against Pseudomonas aeruginosa than its aminothiazolyl counterpart. Cefclidin had lower affinity and a higher Vmax value for the chromosomal type I beta-lactamase (cephalosporinase) from P. aeruginosa than its aminothiazolyl counterpart. No differences between the affinities ...

Cephalosporinases of Enterobacter cloacae and Citrobacter freundii were responsible for resistance to newer cephalosporins such as cefotaxime and ceftazidime but not BMY-28142. Interaction of these cephalosporins including hydrolysis, binding, inhibition, and inactivation with cephalosporinases from E. cloacae GN7471 and C. freundii GN7391 were studied. BMY-28142 was much more stable against th...