Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C1275122 (TEM)
 21,810 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tympanometric measurement has been made on centric relation and working side and non-working side in 19 healthy subjects (12 males and 7 females aged 23-27) and the following conclusions have been obtained: 1. The Tympanogram in the healthy subjects showed a symmetrical pattern, being of type A bilaterally, in all the cases, and no lateral or sexual difference was seen any item of measurement. 2. S. C. value increased in order of centric relation, working side and non-working side, but decreased in IMP., PRS. and EAC.. 3. Significant differences were observed in the items of measurement regarding S. C. and IMP. all between centic relation and working side, centric relation and non-working side, working side and non-working side. These findings show a correlation between the function of middle ear and the horizontal mandibular position. Therefore these findings suggest the possibility of tympanometric measurement becoming one of the parameters as the method for objective evaluation of the mandibular position as the change in the function of the middle ear.
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PMID:[Objective evaluation of the mandibular position by the change in the function of the middle ear. 1. Centric relation and lateral eccentric position]. 213 5

In 1996, Serratia marcescens KU3838 was isolated from the urine of a patient with a urinary tract infection at a hospital in northern Japan and was found to contain the plasmid pKU501. Previously, we determined that pKU501 carries bla(IMP) and the genes for TEM-1-type beta-lactamases as well as producing both types of beta-lactamases (H. Yano, A. Kuga, K. Irinoda, R. Okamoto, T. Kobayashi, and M. Inoue, J. Antibiot. 52:1135-1139, 1999). pKU502 is a recombinant plasmid that contains a 1.5-kb DNA fragment, including the metallo-beta-lactamase gene, and is obtained by PCR amplification of pKU501. The sequence of the metallo-beta-lactamase gene in pKU502 was determined and revealed that this metallo-beta-lactamase gene differed from the gene encoding IMP-1 by one point mutation, leading to one amino acid substitution: 640-A in the base sequence of the IMP-1 gene was replaced by G, and Ser-196 was replaced by Gly in the mature enzyme. This enzyme was designated IMP-6. The strains that produced IMP-6 were resistant to carbapenems. The MICs of panipenem and especially meropenem were higher than the MIC of imipenem for these strains. The k(cat)/K(m) value of IMP-6 was about sevenfold higher against meropenem than against imipenem, although the MIC of meropenem for KU1917, which produced IMP-1, was lower than that of imipenem, and the MIC of panipenem was equal to that of imipenem. These results support the hypothesis that IMP-6 has extended substrate profiles against carbapenems. However, the activity of IMP-6 was very low against penicillin G and piperacillin. These results suggest that IMP-6 acquired high activity against carbapenems, especially meropenem, via the point mutation but in the process lost activity against penicillins. Although IMP-6 has reduced activity against penicillins due to this point mutation, pKU501 confers resistance to a variety of antimicrobial agents because it also produces TEM-1-type enzyme.
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PMID:Plasmid-encoded metallo-beta-lactamase (IMP-6) conferring resistance to carbapenems, especially meropenem. 1130 93

A multidrug-resistant plasmid encoding TEM-1, SHV-12, and a variant of IMP-2 metallo-beta-lactamase, designated IMP-8, was identified from a clinical isolate of Klebsiella pneumoniae. There are four nucleotide differences between bla(IMP-2) and bla(IMP-8), resulting in two amino acid differences. bla(IMP-8) was also found to be carried by an integron-borne gene cassette similar to the bla(IMP-2) cassette.
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PMID:Identification of a plasmid encoding SHV-12, TEM-1, and a variant of IMP-2 metallo-beta-lactamase, IMP-8, from a clinical isolate of Klebsiella pneumoniae. 1145 99

The combined effects of (-)-epigallocatechin gallate (EGCg) and beta-lactams were investigated against various beta-lactamase-producing clinical isolates, including 21 Staphylococcus aureus, 6 Escherichia coli, 3 Klebsiella pneumoniae and 8 Serratia marcescens strains. Penicillin in combination with EGCg at 12.5 microg mL(-1) showed the most potent synergy against 100% penicillinase-producing S. aureus. However, cefotaxime or imipenem in combination with higher concentration of EGCg (100 microg mL(-1)) only showed slight synergy against 2 of 17 Gram-negative rods. Similar to the effect on the penicillinase from S. aureus, however, EGCg also directly inhibited the extracted beta-lactamases from the Gram-negative rods, thereby protecting beta-lactams from inactivation. The different effects of the combinations on different beta-lactamase-producing species were confirmed to be related to the cellular locations of beta-lactamases. In contrast to a 32.7% extracellular fraction of total beta-lactamase activity in a penicillinase-producing S. aureus, the fractions were 0.6%, 0.6% and 1.2% in a TEM-derived extended-spectrum beta-lactamase-producing E. coli, an inhibitor-resistant beta-lactamase-producing K. pneumoniae and an IMP-producing S. marcescens, respectively. In conclusion, the combination of penicillin with EGCg showed potent synergy against penicillinase-producing S. aureus in-vitro. The combinations of beta-lactams and EGCg against beta-lactamase-producing Gram-negative rods do indicate a limitation owing to the cellular location of beta-lactamases.
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PMID:Restoration of antibacterial activity of beta-lactams by epigallocatechin gallate against beta-lactamase-producing species depending on location of beta-lactamase. 1284 32

Doripenem is a broad-spectrum parenteral carbapenem under clinical development in Japan and North America. Its activities against (i) Pseudomonas aeruginosa isolates with graded levels of intrinsic efflux-type resistance, (ii) mutants with various combinations of AmpC and OprD expression, (iii) PU21 transconjugants with class A and D beta-lactamases, and (iv) P. aeruginosa isolates with metallo-beta-lactamases were tested by the agar dilution method of the National Committee for Clinical Laboratory Standards. Selection of resistant P. aeruginosa mutants was investigated in single- and multistep procedures. Doripenem MICs for isolates without acquired resistance mostly were 0.12 to 0.5 microg/ml, whereas meropenem MICs were 0.25 to 0.5 microg/ml and imipenem MICs were 1 to 2 microg/ml. The MICs of doripenem, meropenem, ertapenem, and noncarbapenems for isolates with increased efflux-type resistance were elevated, whereas the MICs of imipenem were less affected. The MICs of doripenem were increased by the loss of OprD but not by derepression of AmpC; nevertheless, and as with other carbapenems, the impermeability-determined resistance caused by the loss of OprD corequired AmpC activity and was lost in OprD- mutants also lacking AmpC. The TEM, PSE, PER, and OXA enzymes did not significantly protect P. aeruginosa PU21 against the activity of doripenem, whereas MICs of > or =16 microg/ml were seen for clinical isolates with VIM and IMP metallo-beta-lactamases. Resistant mutants seemed to be harder to select with doripenem than with other carbapenems (or noncarbapenems), and the fold increases in the MICs were smaller for the resistant mutants. Single-step doripenem mutants were mostly resistant only to carbapenems and had lost OprD; multistep mutants had broader resistance, implying the presence of additional mechanisms, putatively including up-regulated efflux. Most mutants selected with aminoglycosides and quinolones had little or no cross-resistance to carbapenems, including doripenem.
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PMID:Doripenem versus Pseudomonas aeruginosa in vitro: activity against characterized isolates, mutants, and transconjugants and resistance selection potential. 1527 24

The many and diverse beta-lactamases produced by bacteria, particularly by Gram-negative pathogens, are increasingly posing a serious threat to the clinical utility of beta-lactams. First-generation inhibitors (clavulanic acid, sulbactam, tazobactam) focus on Ambler class A enzymes. However, recent structural upgrades of class A beta-lactamases (e.g. TEM, SHV) have extended their spectrum (extended-spectrum beta-lactamases and carbapenemases [Sme, NMC-A, IMI-1]) and have brought about the possibility of beta-lactamase-inhibitor resistance. Furthermore, the mobilisation and spread of originally chromosomal class C enzymes (CMY, MIR), the growing clinical importance of class B enzymes (IMP, VIM), the emergence of inhibitor-resistant, broad spectrum class D (OXA) enzymes and the co-existence of different classes of beta-lactamases in the same pathogen have spurred research toward universal inhibitors. A complicating issue is target accessibility in Gram-negative bacteria, particularly in Enterobacter, Acinetobacter, Pseudomonas, Stenotrophomonas and other organisms, which is necessary in order for the inhibitor to synergise with vulnerable beta-lactam antibiotics. Several new, broad-spectrum inhibitors have emerged: cephem sulfones and oxapenems are upgrades of penam sulfones and oxapenams, respectively, with cephem sulfones possibly extending their inhibition to class B metallo-enzymes; and boronates and phosphonates are designed de novo, based on common structural and mechanistic features of serine beta-lactamases.
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PMID:Beta-lactamase inhibitors: evolving compounds for evolving resistance targets. 1546 59

Resistance to beta-lactam antibiotics continues to increase, mostly due to the presence of various beta-lakta mases. As a result of the ability of the plasmids to acquire additional resistance determinants, many of the beta-lactamase producing pathogens became multidrug resistant. The most important beta-lactamases which compomise the use of beta-lactams nowdays are extended-spectrum beta-lactamases, inhibitor-resistant TEM and SHV beta-lactamases and carbapenemases. Carbapenemases are beta-lactamases which hydrolyse carbapenems. They belong to molecular classes A, B, and D. Class A comprises carbapenemases sensitive to inhibition by clavulanic acid. Most of them are chromosomaly encoded, but some of them are plasmid-mediated such as KPC-1 in Klebsiella pneumoniae and GES-2 in Pseudomonas aeruginosa. The class B carbapenemases are metallo-beta-lactamases of the IMP or VIM group. The class D carbapenemases are the most frequent in Acinetobacter baumannii but confer resistance to carbapenems only if other resistance mechanisms such as porin alterations, are present. Inhibitor resistant beta-lactamases are one of the most important causes of resistance to beta-lactam-inhibitor combinations. The resistance to these formulations can be also due to hyperproduction of TEM-1 beta-lactamase, modifications of the outer membrane proteins or production of OXA-type enzymes. IRT enzymes are derived from parenthal TEM-1 or TEM-2 beta-lactamases by point mutations in the beta-lactamase gene. The frequent use of beta-lactamase inhibitors in hospitals and general practice pose a selection pressure which favours spread of such strains in hospitals and community.
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PMID:[Beta-lactamases and their role in resistance. PART 2: beta-lactamases in 21st century]. 1614 68

The acquired resistance against the wide-spectrum and highly stable beta-lactams including third-generation cephalosporins (3GC) and carbapenems is constinuously increasing and widespead with the discovery of various plasmid-encoded, or genes cassette or integrons coding for a novel beta-lactamase, always a major mechanism of resistance. To explain resistance against 3GC, with the continuing story with TEM and SHV mutated enzymes, several types of ESBL (class A) emerge the CTX-M type, at least CTX-M-40, but also other non predominant types intitled BES, GES, PLA, PER, VEB. The wider resistance including 3GC, cephamycins and beta-lactamase inhibitor is correlated to synthesis of transferable cephalosporinases (class C) usually located in the chromosome but mobilized from Enterobacter spp., Citrobacter freundii, Hafnia alvei, Morganella morganii, Aeromonas caviae. Such genes encoded the following types: ACC-1, ACT-1, CFE-1, CMY group, DHA-1, FOX group, MIR-1, MOX-1. Finally the resistance against carbapemens e.g. imipenem originally restricted to Pseudomonas aeruginosa, then to Acinetobacter baumannii and finally to enterobacteria is related to production of novel enzymes (classes B, D and A) denominated IMP, VIM SME, GIM, OXA, KPC. A striking exemple of evolution towards more and more resistance is given by Salmonella, even from animal origins, a great threat fo public health. So far it appears necessary to perform molecular approaches to identify such enzymatic production. Finally because the absence of real new drugs, the discovery of some progenitors of the gene beta-lactamase, a strict control of beta-lactam antibiotics must be provide not only in medecine or veterinary field but also in agriculture, including aquaculture for example.
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PMID:[Beta-lactamases of Gram negative bacteria: never-ending clockwork!]. 1642 Sep 89

The most common mechanism of resistance to beta-lactam antibiotics is the production of beta-lactamases. These enzymes are encoded by genes that evolve rapidly, thus constituting a group characterized by high levels of molecular diversity. Most of the genetic determinants of resistance to beta-lactam antibiotics characterized until now were obtained from clinical isolates. This study was designed in order to exploit the presence of beta-lactamase gene sequences in an aquatic environment, and to get information on the distinctive features of those sequences when compared to others available on databases. DNA sequences potentially encoding proteins of three different families of clinically relevant beta-lactamases were assessed: TEM, IMP and OXA-2 derivatives. The presence of bla sequences in DNA extracted from water samples from the lagoon Ria de Aveiro was checked by PCR and hybridization. Sequences representing the three families of beta-lactamases studied were detected. The molecular diversity of the amplicons was assessed by cloning and sequence analysis, and denaturing gradient gel electrophoresis (PCR-DGGE) separation. Most of the retrieved sequences (particularly sequences representing bla(TEM)and bla(OXA-2)) were identical or very similar to beta-lactamase gene sequences previously characterized from clinical isolates. Phylogenetic analysis suggests that this aquatic ecosystem is a reservoir of molecular diverse putative bla sequences. The patterns of molecular diversity found within the beta-lactamase gene families studied do not correspond to those reported in studies focussing on clinical isolates.
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PMID:Analysing diversity among beta-lactamase encoding genes in aquatic environments. 1668 74

The beta-lactamase (BLA) genes, the genes for aminoglycosides-modifying enzymes (AMEs), disinfectant-sulfanilamide resistance (qacEDelta1-sul1) genes, class 1 integrase (intl1) gene, and the qnr gene associated with plasmid-mediated quinolone resistance were analyzed using PCR and verified by DNA sequencing for 31 clinical isolates of multidrug-resistant Acinetobacter baumannii (MDRAB). The organism typing was performed by pulsed-field gel electrophoresis (PFGE). The positive rate of ADC, TEM, PER, and DHA of BLA genes were 100%, 61.3%, 19.4%, and 3.2%, respectively; however, the genes of SHV, OXA-23 group, OXA-24 group, GES, VIM, IMP, and qnr gene were negative. The positive rate of the genes of AMEs for aac (3)-I, aac (6')-I, ant (3")-I, ant (2")-I, aac (3)-II, and aac (6')-II were 67.7%, 45.2%, 29.0%, 22.6%, 12.9%, and 3.2%, respectively. The positive rate of qacEDelta1-sul1 and intl1 were 80.6% and 58.1%, respectively. Six different PFGE clones were found, of which two dominated. The findings show that clinical isolates of MDRAB harbor various kinds of resistance genes.
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PMID:Detection of drug resistance-associated genes of multidrug-resistant Acinetobacter baumannii. 1848 41


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