Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.3.1.28 (chloramphenicol acetyltransferase)
 5,100 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Distribution of genetic determinants of resistance to streptomycin, kanamycin, chloramphenicol, tetracycline, sulfanilamides and trimethoprim in strains of Salmonella isolated from studied. The majority of the resistant strains carried the genes of aminoglycoside-3"-phosphotransferase, type I aminoglycoside-3'-phosphotransferase, type I chloramphenicol acetyltransferase and type II dihydropteroate synthetase. Tetracycline resistance in the strains was often due to the class B tetracycline resistance genetic determinants. It was suggested that the resistance mechanisms controlled by these genes provided higher levels of resistance to the above drugs in Salmonella as compared to the other mechanisms. Plasmid resistance genes were detected in more than 90 per cent of the clinical strains and in 35 per cent of the sporadic strains of S. typhimurium. The antibiotic resistance of the Salmonella strains of other serovars was not as a rule controlled by the plasmid genes.
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PMID:[Genetic determinants of antibiotic resistance in bacteria of the genus Salmonella]. 296 Feb 64

Tetracycline resistance protein (TET) of Bacillus subtilis plasmid pNS1 was detected by immunoblot analysis using a specific antibody to TET-chloramphenicol acetyltransferase (CAT) fusion protein. In two-dimensional electrophoresis, one major spot which seemed to be the pNS1-encoded TET (pNS1-TET), was detected by immunostaining. Its molecular weight and isoelectric point were approximately 52 kDa and 6.2, respectively. Judging from the nucleotide sequence, the pNS1-TET is a very hydrophobic, 50 kDa protein. Therefore, the 52 kDa protein is thought to be an intact form of the pNS1-TET produced by B. subtilis cells.
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PMID:Detection of tetracycline resistance protein encoded by Bacillus subtilis plasmid pNS1. 836 57

This article reviews the molecular mechanisms of resistance to fluoroquinolones, erythromycin, chloramphenicol, tetracycline, and trimethoprim-sulfamethoxazole in Streptococcus pneumoniae. Resistance to fluoroquinolones primarily involves mutations in the DNA gyrase gene, gyrA, and in the topoisomerase IV genes, parC and parE, although in vitro studies have indicated that some strains may use an efflux mechanism for resistance to certain fluoroquinolones. Ciprofloxacin resistance results from initial and necessary mutations in ParC leading to low-level resistance and subsequent mutations in GyrA leading to high-level resistance. Sparfloxacin resistance results from initial mutations in GyrA, with ParC mutations occurring subsequently. A single amino acid substitution in ParE has also been associated with low-level resistance in S pneumoniae. Two mechanisms have been described for resistance to erythromycin. Coresistance to macrolides, lincosamides, and streptogramin B type antibiotics is a result of modification of the ribosome through methylation of an adenine residue in domain V of the 23S rRNA. This methylation is encoded by the methylase gene, ermAM. Resistance only to 14-and 15-membered macrolides is a result of efflux of the antibiotic from the cell, encoded by the gene, mefE, in S pneumoniae, and appears to be rapidly emerging as the predominant mechanism of resistance to erythromycin in many countries. The production of chloramphenicol acetyltransferase, an enzyme capable of catalyzing the conversion of chloramphenicol to its nonfunctional 1-acetoxy, 3-acetoxy, and 1,3-diacetoxy derivatives, leads to chloramphenicol resistance in S pneumoniae. Chloramphenicol acetyltransferase is encoded by a cat gene identical to the cat gene from the Staphylococcus aureus plasmid, pC194. Tetracycline resistance occurs through ribosomal protection encoded by the genes tet(M) and tet(O). It is possible that the Tet(M) and Tet(O) proteins cause tetracycline to be released from the ribosome, although the precise mechanism remains unclear. Resistance to trimethoprim is mediated through a single amino acid substitution in the chromosomal dihydrofolate reductase gene of S pneumoniae, which is thought to disrupt the bond with trimethoprim without affecting the action of the dihydrofolate reductase. Sulphonamide resistance appears to result from repetitions of one or two amino acids in the chromosomal dihydropteroate synthase. Although resistance exists to nearly all antimicrobial agents used in the treatment of S pneumoniae infections, ongoing research into new or alternative therapies is encouraging.
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PMID:Molecular mechanisms of resistance to commonly used non-betalactam drugs in Streptococcus pneumoniae. 1050 13

The role of two chaperone proteins, DnaK and the cooperating factor DnaJ, in Escherichia coli antibiotic susceptibility to three antibiotics (a beta-lactam, chloramphenicol, tetracycline) has been studied. It was found that null dnaJ and dnaKdnaJ mutants are impaired in the functions leading to antibiotic susceptibility. The secretion of beta-lactamase to the periplasmic space is diminished in both mutants, and the additive effect of the two mutations was observed. The activity of chloramphenicol acetyltransferase is also impaired in an additive manner in both mutant strains. Tetracycline uptake is changed only in the double deletion mutant. These defects were observed only during incubation at high temperature (42 degrees C). Efficient complementation of some of these defects by the wild-type alleles introduced on low-copy number plasmid was achieved. Minimal inhibitory concentrations and the titer of the wild-type strains, delta dnaJ and delta dnaKdnaJ mutants treated with ampicillin, chloramphenicol, and tetracycline were also determined. Higher susceptibility of both mutants to chloramphenicol and tetracycline, as compared to their wild-type parent, was observed only after 1 h preincubation of cultures at 42 degrees C. On the contrary, both mutants were less susceptible to ampicillin than their parent strain.
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PMID:Antibiotic susceptibility of Escherichia coli dnaK and dnaJ mutants. 1099 Feb 66