Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0276640 (TEM)
 20,729 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We obtained two R plasmids, i.e., Rms195 and Rms298, from a clinical isolate, E. coli GN5503. Penicillin beta-lactamase (PCase) was extracted from ML1410 Rms195+ and Rms298+, and was purified by chromatography. Rms195 PCase was identical to the type I PCase mediated by R-TEM, RI and Rms212. The isoelectric point of Rms298 PCase was 5.9 and its molecular weight was 21,000 +/- 1,000. The substrate profile and physiochemical properties indicate that Rms298 PCase belongs to the type IV PCase mediated by Rms139 isolated from Pseudomonas aeruginosa.
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PMID:Biochemical properties of a penicillinase from Escherichia coli carrying Rms 298. 2 3

Ampicillin-resistant Haemophilus influenzae type B have been reported only during the past year. Five clinical isolates from the U.S. and Germany all had the TEM-type beta-lactamase which is known to be transferred widely among other gram-negative bacilli. Unlike those bacilli, however, the H. influenzae cell had very little barrier to entry of penicillins. This greater permeability of the H. influenzae cell to penicillins appeared to reduce the protective effect of its beta-lactamase, in that acquisition of the TEM-type beta-lactamase increased levels of resistance to penicillins much less for individual cells of H. influenzae than for those of Escherichia coli. Large inocula of either species appeared highly resistant. The unusually low level of resistance of individual cells of H. influenzae containing the TEM-type beta-lactamase may have delayed their emergence or recognition, and has unresolved clinical implications.
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PMID:Ampicillin-resistant Haemophilus influenzae type B possessing a TEM-type beta-lactamase but little permeability barrier to ampicillin. 4 83

Gonococci, which had acquired a TEM-type of penicillinase widely distributed among gram-negative bacilli, appeared in February, 1976, and soon accounted for 9% of isolates at a clinic in Liverpool. In 45 patients infected by such gonococci, the frequency of complications did not suggest reduced communicability or invasiveness, and usual forms of treatment with penicillins always failed. Spectinomycin succeeded in 21 (95%) of 22 patients treated, blt tetracyclines succeeded in only 13 (68%) of 19. Appropriate laboratory tests for recognising penicillinase-producing gonococci must be used since such gonococci have already been transferred to other parts of the U.K. Penicillinase-stable cephalosporins were active in vitro and could prove to be the future treatment of choice.
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PMID:Penicillinase-producing Gonococci in Liverpool. 6 50

Two beta-lactamase-producing strains of Neisseria gonorrhoeae were studied. The substrate profile, molecular weight, and isoelectric point of their beta-lactamases were similar to those of the TEM-1 enzyme produced by many gram-negative bacilli. The gonococcal beta-lactamase was cell bound during exponential growth and was most likely located in the periplasm. Penicillin hydrolysis was efficient in intact cells, suggesting that the cell-bound beta-lactamase was freely accessible to benzylpenicillin. Both beta-lactamase-producing strains of N. gonorrhoeae contained an additional multicopy plasmid with a mass of 3.3 megadaltons (Mdal). A spontaneous penicillin-susceptible revertant lacked both beta-lactamase activity and the 3.3-Mdal plasmid, providing evidence for plasmid-mediated penicillin resistance. During a shift from GC medium to rich MOPS medium, growth of the penicillin-susceptible revertant in contrast to that of the plasmid-carrying strain was markedly impaired, suggesting a physiological effect due to the presence of the 3.3-Mdal plasmid.
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PMID:Contribution of a TEM-1-like beta-lactamase to penicillin resistance in Neisseria gonorrhoeae. 9 28

Important discrepancies in isoelectric points (pI) of beta-lactamases were observed depending on the experimental procedure used for their determination: isoelectric focusing (IEF) in sucrose density gradients or analytical IEF in thin-layer polyacrylamide gels (PA). The variations, negligable in the case of TEM-like beta-lactamases, appeared to be important in the case of cephalosporinases and are related to an artifact which appears in PA-IEF. This has been clearly shown with beta-lactamase preparations from the following bacterial strains: Pseudomonas aeruginosa NCTC 8203 (pI = 8.7), P. aeruginosa NCTC 10701 (pI = 9.4), and Proteus morganii NCTC 235 (pI = 8.3). The data previously obtained by PA-IEF were much lower.
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PMID:Beta-lactamases: determination of their isoelectric points. 9 31

The antibacterial activity of cephaloridine, cephalothin, cephalexin, cephradine, cefazolin, cefamandole, cefuroxime and cefoxitin was determined for six beta-lactamase-producing gonococci isolated in Great Britain and the USA. Cefuroxime was most active against small and large inocula, then cefoxitin, while cephaloridine was least active. Cefamandole was more active than cefazolin and cephalothin, but only on small inocula, and these three antibiotics, with the slightly inferior cephalexin and cephradine, all had moderate activity against large inocula. The inoculum effect (or lack of it) with cephaloridine, cefamandole, cefoxitin, and possibly cefazolin and cephalothin, may be explicable in terms of the level of their susceptibility to enzymic degradation, but this appears not to be true of the inoculum effect with cefuroxime, cephalexin and cephradine. The enzymes from the various strains had closely similar isoelectric points, apparently the same as that for TEM I from E. coli.
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PMID:The activity of cephalosporins on beta-lactamase-producing Neisseria gonorrhoeae. 9 33

beta-Lactamase activity was detected in cell-free preparations obtained from ultrasonic treatment of Neisseria gonorrhoeae after growth in liquid medium. Crude preparations of beta-lactamase were subjected to affinity chromatography, using several beta-lactam antibiotics as ligands bound to agarose supports. Affinity gels produced by coupling 7-aminocephalosporanic acid or 6-aminopenicillanic acid by their amino groups to carboxyl-terminal agarose via a five- to eight-carbon spacer arm proved to be effective chromatography media. beta-Lactamase preparations subjected to chromatography using these gels were purified 200-fold, with approximately 80% recovery of active material. Purified preparations were judged homogeneous by their behavior during electrophoresis on polyacrylamide in both the presence and absence of sodium dodecyl sulfate. Characterization of the purified enzyme established a molecular weight of approximately 25,000 and an isoelectric point of 5.4. Analyses of substrate specificity, effect of inhibitors, pH, and kinetic parameters were performed. The evidence suggests that the beta-lactamase produced in N. gonorrhoeae closely resembles the character of class IIIa (TEM-type) beta-lactamases.
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PMID:Purification by affinity chromatography and properties of a beta-lactamase isolated from Neisseria gonorrhoeae. 10 75

The ampicillin-resistant Haemophilus influenzae strain Ve445 which caused purulent meningitis and septicaemia in a newborn child in Germany contained a 4.4 megadalton (Mdal) plasmid (pVe445) and produced a TEM type beta-lactamase. The transformation to ampicillin resistance of a sensitive Escherichia coli strain with isolated pVe445 DNA proved that the structural gene for the beta-lactamase resided on this plasmid genome. Molecular DNA-DNA hybridization studies and electron microscope DNA heteroduplex analysis indicated that pVe445 probably contained 38 to 41% of the ampicillin translocation DNA segment (TnA) found on R factors of enteric origin. The TnA fragment present in pVe445 most likely does not contain both of the inverted repeat sequences of TnA. DNA-DNA polynucleotide sequence studies indicated that the 4.4 Mdal plasmid pVe445 was unrelated to the 30 to 38 Mdal H. influenzae R plasmids but was closely related to the 4.1 Mdal ampicillin resistance specifying H. influenzae plasmid RSF0885 isolated in the U.S.A. The H. influenzae plasmid pVe445 shared 91% of its base sequences with the beta-lactamase specifying Neisseria gonorrhoeae plasmid pMR0360 (4.4 Mdal) and had 85% of its base sequences in common with the beta-lactamase specifying N. gonorrhoeae plasmid pMR0200 (3.2 Mdal). All of the four 3.2 to 4.4 Mdal beta-lactamase specifying R plasmids of H. influenzae and N. gonorrhoeae investigated probably have a common evolutionary origin.
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PMID:Molecular characterization of a small Haemophilus influenzae plasmid specifying beta-lactamase and its relationship to R factors from Neisseria gonorrhoeae. 11 Sep 7

The effects of therapeutic concentrations of ampicillin on non-beta-lactamase and beta-lactamase producing strains of Neisseria gonorrhoeae were studied. A small but significant fraction of bacteria in a gonococcal population was found to respond in a bacteriostatic rather than a bactericidal way upon ampicillin treatment. In agreement with this was the finding of morphologically unaltered cells in the scanning electron microscope after ampicillin exposure. Ampicillin treatment of beta-lactamase producing gonococci caused a significant release of the enzyme into the surrounding growth media. However, initially all beta-lactamase activity was cellbound. The rate of initial ampicillin hydrolysis was much higher in intact cells of N. gonorrhoeae (TEM-1) than in cells of Escherichia coli K-12 (TEM-1). This suggests that the diffusion rate of ampicillin is much higher in the former organism. The viability of gonococci (TEM-1) was unlike E. coli (TEM-1) affected by low concentrations of ampicillin. However, after complete hydrolysis of ampicillin, viable gonococci (probably bacteriostatic reacting cells) were able to initiate new growth. This heterogeneity of the cell population to penicillin killing is probably one reason why beta-lactamase producing gonococci despite a rather low MIC-value to ampicillin cause infections that are not susceptible to therapy by this agent.
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PMID:Effects of low ampicillin concentrations on penicillin sensitive and beta-lactamase producing strains of Neisseria gonorrhoeae. 11 31

Ampicillin-resistant Haemophilus influenzae does occur now in the FRG. In one isolate a plasmid with resistance genes (R-factor) could be demonstrated as cause of the ampicillin resistance. This R-factor influences production of a beta-lactamase of the TEM type which destroys ampicillin. The infectious nature of the ampicillin resistance was proven by the fact that it was transferable to other bacterial species through cocultivation. Parallel to ampicillin resistance tetracycline resistant Haemophilus influenzae has occurred in the FRG. Here the resistance was equally bound to plasmids. These R-factors are infectious as well. Molecular analysis of the 3 isolated resistance factors in Haemophilus influenzae showed that they carry the same resistance genes which are known from R-factors of Enterobacteriaceae. In the therapy of purulent infections due to Haemophilus influenzae such as childhood meningitis one can no longer rely on general ampicillin sensitivity of the offender. Apart from ampicillin and tetracycline resistant Haemophilus influenzae chloramphenicol resistance has been observed in a few cases.
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PMID:[Infectious resistance to antibiotics in Haemophilus influenzae (author's transl)]. 30 40


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