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 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

Recent reports that members of the family Enterobacteriaceae that produce high levels of certain beta-lactamases are often resistant to ticarcillin-clavulanate prompted this study to assess the relationship between type and amount of enzyme produced and susceptibility to ticarcillin-clavulanate, piperacillin-tazobactam, and cefoperazone-sulbactam. Agar dilution MICs were determined by using 73 strains of Enterobacteriaceae that produced a single beta-lactamase that had been characterized and quantified and a beta-lactamase-negative control strain of Escherichia coli. For E. coli and Klebsiella pneumoniae, MICs of each combination increased as levels of TEM, SHV-1, or class IV enzymes increased. However, the percentage of strains that were resistant was highest for ticarcillin-clavulanate (32%), with only 18 and 6% resistant to piperacillin-tazobactam and cefoperazone-sulbactam, respectively. Strains producing PSE-1, regardless of level, were resistant or moderately susceptible to ticarcillin-clavulanate but were susceptible to piperacillin-tazobactam and cefoperazone-sulbactam. HMS-1 and OHIO-1 beta-lactamases were associated with resistance to ticarcillin-clavulanate and piperacillin-tazobactam, respectively. High levels of class IV enzymes in Klebsiella oxytoca were associated with resistance to all three combinations. These results indicate that the level and type of beta-lactamase produced by members of the family Enterobacteriaceae are important determinants of susceptibility to beta-lactam-inhibitor combinations, especially ticarcillin-clavulanate.
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PMID:Beta-lactamase production in members of the family Enterobacteriaceae and resistance to beta-lactam-enzyme inhibitor combinations. 234 69

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

Four major mechanisms cause resistance to beta-lactams in Pseudomonas aeruginosa: (i) cell wall impermeability gives broad-spectrum intrinsic resistance to all beta-lactams except imipenem, (i) loss of D-group outer membrane proteins correlates with narrow spectrum imipenem resistance, (iii) plasmid mediated beta-lactamases compromise antipseudomonal penicillins, cefoperazone and cefsulodin, and (iv) chromosomal beta-lactamase hyper-production compromises most beta-lactams except carbenicillin and imipenem. Meropenem was tested in vitro against P. aeruginosa isolates, mutants and transconjugants with these mechanisms. Meropenem had impaired activity (MIC 1-2 mg/l compared to 0.25 mg/l for sensitive isolates) for organisms with broad-spectrum intrinsic resistance. MICs of meropenem also were elevated (to 1-2 mg/l) for mutants with D2-protein-deficiency-associated imipenem resistance. Most plasmids encoding TEM, OXA or PSE beta-lactamases did not increase the MIC (0.12 mg/l) of meropenem for P. aeruginosa PU21. Decreased susceptibility (MIC 4 mg/l), however, was observed when plasmids coding the uncommon NPS-1, PSE-2 and OXA-3 enzymes were present in this strain. MICs of meropenem remained identical for chromosomal beta-lactamase-inducible P. aeruginosa strains and their enzyme-derepressed and basal mutants, indicating that the chromosomal beta-lactamase could not protect against the new carbapenem, regardless of its mode of expression.
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PMID:Comparative activity of meropenem against Pseudomonas aeruginosa strains with well-characterized resistance mechanisms. 255 57

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

CP-65,207 is a new parenteral penem antibiotic with a broad spectrum that includes gram-positive, gram-negative, and anaerobic microorganisms, with MICs for 90% (MIC90s) of the majority of 1,101 clinical pathogens tested being less than or equal to 1 microgram/ml. The compound was from 10- to 100-fold more active than cefoxitin and broad-spectrum cephalosporins against gram-positive bacteria and anaerobes. CP-65,207 was less active than imipenem for staphylococci, group A streptococci, and Enterococcus faecalis. Against members of the family Enterobacteriaceae, CP-65,207 was in general 100-fold more active than cefoxitin, 5- to 10-fold more active than broad-spectrum cephalosporins, and 2-fold more active than imipenem. Fresh clinical isolates that were resistant to broad-spectrum cephalosporins were highly susceptible to CP-65,207 and imipenem (MIC90, 1 microgram/ml). Isolates of Enterococcus faecalis, Serratia marcescens, and anaerobic Peptococcus spp. had MIC90s of 8, 2, and 3.12 micrograms/ml, respectively. CP-65,207 was not very active against methicillin-resistant staphylococci or Pseudomonas aeruginosa. Killing kinetics showed that against some strains CP-65,207 is rapidly bactericidal at concentrations well below those required to achieve a similar degree of killing with cefotaxime, ceftazidime, and ceftriaxone. CP-65,207 was only slightly susceptible to hydrolysis by type I cephalosporinases and TEM-1, SHV-1, and PSE-2 plasmid-encoded enzymes. It had the highest affinity for penicillin-binding proteins 2, 1A, 1B, and 3 in cell-free preparations of Escherichia coli W-7.
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PMID:In vitro activity of CP-65,207, a new penem antimicrobial agent, in comparison with those of other agents. 267 70

SM-7338, a new carbapenem, inhibited most members of the family Enterobacteriaceae at MICs of 0.015 to 0.25 microgram/ml, including Klebsiella oxytoca, Citrobacter freundii, Enterobacter cloacae, and Proteus vulgaris isolates resistant to cefotaxime, ceftazidime, piperacillin, and gentamicin. It was two- to eightfold more active than imipenem, but it inhibited Pseudomonas aeruginosa at 1 to 8 micrograms/ml, which was comparable to the activity of imipenem. Haemophilus, Neisseria, and Branhamella species were inhibited by less than or equal to 0.25 microgram/ml, which was superior to the activity of imipenem. SM-7338 inhibited Staphylococcus aureus and coagulase-negative staphylococci at 0.25 microgram/ml, but for methicillin-resistant isolates MICs were 4 to 16 micrograms/ml. Group A, B, and C streptococci and Streptococcus pneumoniae were inhibited by less than or equal to 0.03 microgram/ml. Bacteroides species, including clindamycin-resistant isolates, were inhibited by 0.25 microgram/ml. There was no major inoculum size effect, and the MBCs were within a dilution of the MICs. SM-7338 was more active than imipenem at an acid pH under anaerobic conditions. Plasmid beta-lactamases of TEM-1, TEM-2, TEM-3, TEM-5, SHV-1, SHV-2, PSE-1, PSE-2, PSE-3, OXA-2, OXA-3, OXA-4, OXA-5, and OXA-7; Staphylococcus aureus enzymes; and the chromosomal beta-lactamases P-99 and K-1; Morganella species; and Proteus vulgaris did not hydrolyze SM-7338. The repeated transfer of organisms increased the MICs of SM-7338, as it did the MICs of imipenem.
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PMID:In vitro activity and beta-lactamase stability of a new carbapenem, SM-7338. 278 93

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

The beta-lactamase inhibitory properties of 6-acetylmethylene penicillanic acid (6-AMPA) were investigated and compared with those of other beta-lactamase inhibitors. 6-AMPA inhibited the TEM-1, TEM-2, SHV-1, PSE-1, PSE-2, PSE-3, PSE-4, OXA-2, OXA-3, and Staphylococcus aureus beta-lactamases. It also inhibited the chromosomally-mediated beta-lactamases of the Richmond-Sykes type Ia, Ic and Id type and the type IV Klebsiella enzymes. Beta-lactamases of Branhamella catarrhalis and Bacteroides fragilis were inhibited. The 6-AMPA I50 values for various enzymes were less than 0.01 microgram/ml TEM-1 and PSE-4, and 0.01 microgram/ml SHV-1, 0.02 microgram/ml S. aureus, 0.04 microgram/ml Proteus vulgaris, 0.04 microgram/ml K. oxytoca, 6.8 micrograms/ml P99, and 9.7 micrograms/ml Sabath-Abraham Pseudomonas enzyme. With isolated beta-lactamases 6-AMPA was a more potent inhibitor than clavulanate or sulbactam. 6-AMPA was an irreversible inhibitor of beta-lactamases. The penetration index for Escherichia coli JT4 was 23 compared to 3 for clavulanate. 6-AMPA at 10 micrograms/ml acted synergistically with ampicillin against beta-lactamase containing bacteria, but it was less active than clavulanate and did not act synergistically with ampicillin against Enterobacter, Citrobacter or Pseudomonas. Although 6-AMPA has excellent beta-lactamase inhibitory properties with isolated enzymes, it is less useful with intact organisms.
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PMID:Beta-lactamase inhibition by acetylmethylene penicillanic acid compared to that of clavulanate and sulbactam. 285 Jan 39

The polymicrobial aetiology of travellers's diarrhoea in 356 tourists travelling in Thailand and Burma was investigated. Besides enterotoxigenic E. coli, Salmonella sp. and Campylobacter fetus ssp. jejuni were identified as the most important enteric pathogens. Minimal inhibitory concentrations of several commonly used antibiotics were determined to reveal the percentage of enteric pathogens being resistant. 36.2% E. coli strains were found to be resistant to ampicillin and 14.3% of the Campylobacter isolates were considered to be resistant to erythromycin. Furthermore, the occurrence of some plasmid-borne beta-lactamases causing resistance to beta-lactam antibiotics was investigated, and the TEM-1 enzyme was found to be the most common one in enteric pathogens. Also a PSE-2-beta-lactamase (which is said to be Pseudomonas-specific) was identified in two strains of E. coli. Finally, the influence of antibiotic misuse on development of resistance was discussed by comparing the conditions in Bangkok and Rangoon.
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PMID:[Antibiotic resistance and distribution of plasmid-encoded beta- lactamases among agents of traveller's diarrhea]. 294 94


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