introduction: resistance of pathogenic organisms to countenance antibiotics has become a worldwide problem with serious consequences on the treatment of infectious diseases. the aim of this study was to evaluate antibiotic resistance and also the detection of transferred antibiotic resistance by plasmid in clinical proteus isolates. materials and methods: a total of 250 urine samples were colle...

Development of fluoroquinolone resistance can involve several mechanisms that include chromosomal mutations in genes ( gyrAB and parCE ) encoding the target bacterial topoisomerase enzymes, increased expression AcrAB-TolC efflux system, acquisition transmissible quinolone-resistance genes. In this study, 176 Salmonella isolates from animals with a broad range ciprofloxacin MICs were collected t...

We have previously reported the transfer of gentamicin resistance (Gmr) plasmids in a mixed culture inter- and intraspecifically between strains of Staphylococcus aureus and Staphylococcus epidermidis isolated at Michael Reese Hospital (Jaffe et al., Antimicrob. Agents Chemother. 21:773-779, 1982). We have now shown that representatives of these plasmids were transferred between apparently nonl...

A single plasmid of 55 kilobases was found in crude cell lysates of each of nine strains of Rhodospirillum rubrum. Restriction endonuclease analysis showed identical fragment patterns with a given nuclease for all plasmids except one, for which an additional EcoRI site was observed. Elimination of the plasmid required that the cells be passaged several times in 25 mM calcium-containing medium, ...

the biodegradation of secondary amines is particularly important due to their propensity for conversion either chemically or microbiologically to n-nitrosamines which are potent carcinogens. in this research, a weak gram-positive organism was isolated from river and identified as mycobacterium. this mycobacterium grows slowly and effectively utilizes piperazine as the sole source of organic, ca...

Amycolatopsis methanolica contains a 13.29-kb plasmid (pMEA300) present both in the free state and integrated at a unique genomic location. A pMEA300-free derivative (strain WV1) was selected, allowing further analysis of pMEA300-encoded functions. Whole cells of strain WV1 could be transformed at high frequencies (approximately 10(6) transformants per microgram of plasmid DNA) with both circul...

The mobilization properties of three plasmids were examined after cotransfer from Shigella flexneri to Escherichia coli. The largest plasmid, pCN1, was shown to be a conjugative R factor that could promote its own transfer and allow cotransfer of a 4.1-kilobase plasmid, pCN3; mobilization of the third plasmid, pCN2 (6.3 kilobases), required the presence of both pCN1 and pCN3. Sequences from pCN...

Plasmid DNA chromatography is a powerful field in constant development and evolution. The use of this technique considered mandatory the production an efficient safe formulation to be applied for plasmid-mediated gene therapy. Concerning this, search ideal chromatographic support/ligand combination motivated scientist pursue continuous improvement on plasmid performance, looking progression lig...

The Mauriceville retroplasmid of Neurospora mitochondria encodes a novel reverse transcriptase that initiates cDNA synthesis de novo (i.e., without a primer) at the 3' CCA of the plasmid transcript's 3' tRNA-like structure (H. Wang and A. M. Lambowitz, Cell 75:1071-1081, 1993). Here, we show that the plasmid reverse transcriptase also initiates cDNA synthesis de novo at the 3' end of tRNAs, lea...

Resveratrol (R), a plant polyphenol, is known to reduce Cu (II) to Cu (I) generating reactive oxygen species that can cleave plasmid DNA. Here we report a surprising observation of a paradoxical relationship between R and Cu whereby plasmid DNA cleaving / degrading activity of R-Cu increased progressively as the ratio of R to Cu was increased i.e., the concentration of Cu was successively reduc...