Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0276640 (TEM)
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Intragenic DNA probes were synthesized by polymerase chain reaction using fragments of the genes of three major types of beta-lactamases (TEM, SHV, CARB) as templates. The TEM probe hybridized with the genes encoding TEM-1, TEM-2 and six extended-spectrum related enzymes (TEM-3 to TEM-7, TEM-2O) in colony hybridizations and Southern-blot analysis. The SHV probe hybridized with the genes for SHV-1, OHIO-1 and four derived extended-spectrum beta-lactamases (SHV-2, SHV-3, SHV-4 and SHV-5). The CARB probe hybridized with the genes for PSE-1 (CARB-2), PSE-4 (CARB-1), CARB-3 and CARB-4. None of the probes hybridized with genes for any of eight oxacillin-hydrolysing enzymes, PSE-2, OXA-1 to OXA-7, ROB-1 and chromosomal beta-lactamases of various Enterobacteriaceae (except Klebsiella pneumoniae) and Pseudomonas aeruginosa. Investigations of Escherichia coli clinical isolates using these probes indicate the presence of a novel type of extended-spectrum, transferable beta-lactamase.
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PMID:Construction by polymerase chain reaction and use of intragenic DNA probes for three main types of transferable beta-lactamases (TEM, SHV, CARB) [corrected]. 193 34

We determined the nucleotide sequence of the blaSHV-2(pBP60-1) gene from Klebsiella ozaenae which confers resistance to broad-spectrum cephalosporins. The structural gene encodes a polypeptide product of 286 amino acids, and the estimated molecular weight of the mature protein is 28,900. Amino acid sequence comparison of the SHV-2pBP60-1 enzyme with all known class A beta-lactamases and homology studies showed that the residues were highly conserved. Furthermore, SHV-2pBP60-1 was clearly related to SHV-1, LEN-1, and OHIO-1. The SHV-2pBP60-1 enzyme differed from SHV-1 isolated from Klebsiella pneumoniae by seven amino acid substitutions. One of these substitutions, the Gly----Ser substitution at position 234, is probably a key region for the novel activity of cefotaxime hydrolysis. A phylogenetic tree was constructed by using all class A beta-lactamases of known sequences by a progressive alignment method. The data suggested that the beta-lactamases of gram-positive Streptomyces, Staphylococcus, and Bacillus species appeared early in evolution, followed by the PSE and CARB enzymes of Pseudomonas species and, more recently, by the SHV-type and TEM-type enzymes found in enteric bacteria. Larger evolutionary distances separated clusters of the gram-positive beta-lactamases than separated clusters of the gram-negative enzymes. Results of this phylogenetic study suggested that extended-spectrum enzymes are recent derivatives that are selected by the use of new cephalosporins.
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PMID:Nucleotide sequence and phylogeny of SHV-2 beta-lactamase. 228 85

The zymogram technique was applied to a beta-lactamase neutralization assay with anti-TEM-1 and anti-TEM-2 sera. Both were shown to contain neutralizing antibodies directed towards various beta-lactamases of Gram-negative bacteria. The quantitative neutralization allowed classification into five groups of the 28 beta-lactamases used as standards and 61 from clinical isolates. In the first were enzymes such as TEM-1 and TEM-2 including TLE-1, SHV-1, SHV-2, penicillinases of Klebsiella pneumoniae and CTX-1. Partial neutralization distinguished two groups containing the CARB group of enzymes, which are different from PSE-2 and PSE-3, and the MAL penicillinases of Levinea malonatica, which are different from L. amalonatica enzymes. Broad spectrum beta-lactamases of K. oxytoca constituted a unique group of partially neutralized enzymes. Among the beta-lactamases not neutralized by either serum were the plasmid-mediated OXA-enzymes, various species-specific beta-lactamases and cephalosporinases. The antigenic similarities of the enzymes appeared to correlate with the extent of similarities of their catalytic properties, namely those of penicillinases. Such comparisons between the beta-lactamase groups provide an indirect approach to the physiological and structural analysis of established and recently evolved beta-lactamases.
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PMID:Immunological comparison of constitutive beta-lactamases of gram-negative bacteria by neutralization in zymogram gels: properties of anti-TEM-1 and anti-TEM-2 sera. 246 Jan 15

The combination of piperacillin and the beta-lactamase inhibitor tazobactam (formerly YTR 830) was studied to determine optimal disk concentrations and dilution testing conditions. In addition, the potency of the combination was compared to that of piperacillin alone. The spectrum of piperacillin was greatly expanded by the addition to tazobactam principally against beta-lactamase producing strains of Haemophilus influenzae, Escherichia coli, Morganella morganii, Proteus vulgaris, Providencia stuartii, Shigella spp., Neisseria gonorrhoeae, and Staphylococcus spp. Tazobactam was active alone against Branhamella catarrhalis (minimum inhibitory concentration [MIC] 50, less than or equal to 1 microgram/ml), gonococci (MIC 50, 0.5-4 micrograms/ml), and N. meningitidis (MIC 50, less than or equal to 1 microgram/ml). Studies with beta-lactamase-producing type strains showed tazobactam to have high affinity for plasmid-mediated enzymes (TEM-1 and 2, SHV-1, HMS-1, and some CARB or OXA types) and not chromosomal beta-lactamases. Piperacillin/tazobactam inhibited 93% of fluoro-quinolone resistant strains at less than or equal to 64/8 micrograms/ml but failed to suppress the growth of 15 strains producing stably depressed cephalosporinases. Comparisons of piperacillin/tazobactam results determined with 100/10-, 100/20-, and 100/30-micrograms disks established the 100/10-micrograms disk as most usable. Among five different MIC combinations the ratio of eight parts piperacillin to one part tazobactam or fixed concentration tests at greater than or equal to 4 micrograms tazobactam/ml were preferred, each producing very low occurrences (less than or equal to 1.6%) of false-resistance or -susceptibility when compared to disk test results. MICs determined by agar and broth microdilution methods were essentially the same. The recommended breakpoints for piperacillin/tazobactam MICs were identical to those now found in the NCCLS susceptibility testing standards with the following exceptions: (1) for tests with H. influenzae and Staphylococcus spp.--susceptible at greater than or equal to 21 mm (MIC less than or equal to 16/2 micrograms/ml) and resistant less than or equal to 20 mm (MIC less or equal to 32/4 micrograms/ml); and (2) all remaining nonspeudomonas isolates would be interpreted by the NCCLS piperacillin enteric bacilli susceptibility criteria. This newer beta-lactamase inhibitor combination appears to be worthy of further in vivo trials guided by these or similar tentative in vitro susceptibility testing parameters.
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PMID:Studies to optimize the in vitro testing of piperacillin combined with tazobactam (YTR 830). 256 Apr 22

Plasmid-mediated beta-lactamases were characterized by DNA hybridization in 371 aminoglycoside resistant gram-negative bacilli with known aminoglycoside resistance mechanism. Positive hybridization was detected in 50% to a TEM-1 probe, in 2% to a SHV-1 probe, and in 3% to both probes simultaneously. No hybridization was obtained to OXA-1, OXA-2, PSE-1/PSE-4/CARB-3 or PSE-2 beta-lactamase probes. TEM-1 beta-lactamase occurred simultaneously in 82% of strains showing the AAC(3)-V type of aminoglycoside resistance mechanism. Using isoelectric focusing as a control method, we found potentially plasmid-encoded beta-lactamases, other than TEM-1 and SHV-1, at various pIs in 13% of 288 randomly selected strains. The pIs of these strains or strains showing positive hybridizations did not fit to pIs of recently characterized plasmid-mediated enzymes against third-generation cephalosporins (e.g. CTX-1). In addition, the strains did not show resistance to cefotaxime or ceftazidime. According to the in vitro susceptibility data ceftazidime and cefotaxime were active against most of the aminoglycoside resistant strains studied. In contrast, the activity of piperacillin was much lower than that of the cephalosporins tested.
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PMID:Plasmid-mediated beta-lactamases among aminoglycoside resistant gram-negative bacilli. 266 97

Transposons coding for beta-lactamases OXA-3, OXA-4, OXA-5, LCR-1, and CARB-3 have been isolated and compared functionally and structurally with transposons for TEM-1, OXA-1, PSE-1, PSE-2, and PSE-4 enzymes. Each beta-lactamase gene type occurred in a unit together with resistance to other antibiotics, particularly streptomycin and sulfonamide but also chloramphenicol, mercuric ion, or gentamicin, kanamycin, and tobramycin. Restriction mapping, gene cloning, and DNA hybridization were used to compare the transposons and to localize their functional components. Although the multiresistance beta-lactamase transposons varied in size from 8 to 25 kb, the similarity of some of their restriction maps suggested a common derivation. Six of 12 transposons contained DNA segments homologous to the tnpR gene of transposon Tn21 and could complement a tnpR- Tn21 derivative. Consequently, these six transposons appear to have evolved from a common progenitor by acquisition of DNA coding for various beta-lactamases and other resistance genes.
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PMID:Molecular structure and interrelationships of multiresistance beta-lactamase transposons. 284 Jun 78

Compound U-76,252 (Upjohn) is a cephalosporin ester that enhances oral absorption of the active free acid cephem, U-76,253. The active form structurally resembles parenteral aminothiazolyl-methoxyimino cephalosporins such as cefotaxime and its desacetyl metabolite. The g-negative antimicrobial activity of U-76,253 A (sodium salt of U-76,253) was most similar to that of cefixime and more potent than that of cefaclor or cefuroxime among the orally administered cephalosporins. Against g-positive bacteria, U-76,253 A was more active than cefixime. U-76,253 A was relatively stable to hydrolysis by five beta-lactamases (Type Ia, TEM-1, K1, CARB-2, and OXA-1), a stability most similar to cefotaxime and superior to that of cefaclor. Only the Type Ia (P99) enzyme was significantly inhibited by U-76,253 (IC 50 = 2.0 microM).
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PMID:In vitro evaluations of U-76,252 (CS-807): antimicrobial spectrum, beta-lactamase stability, and enzyme inhibition. 285 64

Like all penicillins, piperacillin exhibits some susceptibility to beta-lactamases of the penicillinase type, including those produced by Staphylococcus aureus and the TEM, OXA and CARB enzymes isolated from Gram-negative bacilli. Piperacillin is very slightly hydrolyzed by cephalosporinases, which makes it similar to 3rd generation cephalosporins. When tested with Enterobacter cloacae GN 5797 and Pseudomonas aeruginosa NTC 8303, two strains which produce inducible cephalosporinases, piperacillin had moderate inductive activity compared to cefoxitin, a potent inducer. Induction was very low with Enterobacter, but the drug was slightly more sensitive to Pseudomonas. Inhibition of this type of beta-lactamase synthesis was very strong when piperacillin was combined with amikacin and weaker when it was combined with pefloxacin. The piperacillin-amikacin combination prevented the development of piperacillin-resistant mutants of Enterobacter and Pseudomonas and, probably, of all Gram-negative bacilli. In our tests, the piperacillin-pefloxacin combination was of interest only against Enterobacter, and probably against all enterobacteria, since Pseudomonas mutants that resist pefloxacin are fairly easily obtained in vitro.
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PMID:[Enzymologic aspect of piperacillin combinations]. 294 72

Molecular cloning of DNA fragments between 1.5 and 8 kb from BamHI, EcoRI, HindIII, SalI, or Sau3A digests permitted the isolation of structural genes coding for TEM-1, ROB-1, OXA-1, OXA-3, OXA-4, OXA-5, PSE-1, PSE-2, PSE-3, PSE-4, CARB-3, CARB-4, AER-1, and LCR-1 beta-lactamases. Ampicillin-resistant clones were selected and it was confirmed that they contained the respective beta-lactamase genes by isoelectric focusing. Detailed physical maps of 14 different recombinant plasmids were constructed using 8 restriction endonucleases. Plasmid deletions and lacZ fusions were used to localize the beta-lactamase structural genes. DNA probes were constructed for the TEM-1, ROB-1, OXA-1, and PSE-1 genes. Under conditions of high stringency, hybridization was observed between the genes for TEM-1 and TEM-2 or TLE-1, OXA-1 and OXA-4, and PSE-1 and PSE-4 or CARB-3, while the ROB-1 gene probe showed no cross-hybridization. Such bla gene probes should facilitate studies of beta-lactamase molecular epidemiology.
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PMID:Molecular cloning and DNA homology of plasmid-mediated beta-lactamase genes. 303 34

Susceptibility testing of clinical isolates of several gram-negative and gram-positive species showed LY163892 to be more active than cefaclor and cephalexin. OXA-2, TEM-1, TEM-2, PSE-1, CEP-1, CARB-3 and SHV-1 beta-lactamases showed similar activity against LY163892 and cefaclor, whereas OXA-1 hydrolyzed the latter more rapidly. Organisms producing these beta-lactamases, but not TEM-2 and CEP-1, appeared to be more susceptible to LY163892 than cephalexin, although cephalexin proved to be more resistant to beta-lactamase activity. Strains producing TEM-2 and CEP-1 were resistant to LY163892, cefaclor and cephalexin.
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PMID:In vitro activity and beta-lactamase stability of LY163892. 314 Nov 70


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