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Biomedical subjects

S Kresovich

Publications and source records attributed to S Kresovich.

21 records · Page 2Linked to original sources

Cloning and nucleotide sequence of a gene upstream of the eaeA gene of enterohemorrhagic Escherichia coli O157:H7.

A DNA segment located immediately upstream of the eaeA gene of enterohemorrhagic Escherichia coli O157:H7 strain HA1 was cloned and sequenced. This segment contained an open reading frame encoding a predicted protein of 156 amino acids. A database search identified similar open reading frames upstream of the eaeA gene in two other bacterial pathogens, i.e. enteropathogenic E. coli and Citrobacter freundii. The predicted amino acid sequence of the enterohemorrhagic E. coli protein shared 96.8% and 94.2% identity with the enteropathogenic E. coli and C. freundii sequences, respectively. Because the open reading frame is located within the locus of enterocyte effacement region of the E. coli chromosome, a 'hot spot' for insertion of virulence factor genes, and shares high sequence homology with attaching and effacing EPEC and C. freundii, this protein may be associated with pathogenicity of E. coli O157:H7.

Amino Acid Sequence↗

DNA diversity among clinical isolates of Helicobacter pylori detected by PCR-based RAPD fingerprinting.

The RAPD (or AP-PCR) DNA fingerprinting method was used to distinguish among clinical isolates of Helicobacter pylori, a bacterium whose long term carriage is associated with gastritis, peptic ulcers and gastric carcinomas. This method uses arbitrarily chosen oligonucleotides to prime DNA synthesis from genomic sites to which they are fortuitously matched, or almost matched. Most 10-nt primers with > or = 60% G + C yielded strain-specific arrays of up to 15 prominent fragments, as did most longer (> or = 17-nt) primers, whereas most 10-nt primers with 50% G+C did not. Each of 64 independent H. pylori isolates, 60 of which were from patients in the same hospital, was distinguishable with a single RAPD primer, which suggests a high level of DNA sequence diversity within this species. In contrast, isolates from initial and followup biopsies were indistinguishable in each of three cases tested.

Animals↗

The effect of salt concentration on auxin stability in culture media.

The concentrations of indole-3-acetic acid (IAA), naphthaleneacetic acid (NAA) and 2,4-dichlorophenoxyacetic acid (2,4-D) were followed for 35 days in cell-free liquid medium containing 100, 50, or 0% Murashige-Skoog (MS) salt base. Although the concentrations of NAA or 2,4-D remained constant the level of IAA decreased to only 11% of the original concentration after 35 days in the presence of 100% MS salt base. The observed rate of IAA degradation was accelerated by the presence of MS salts.

Journal Article↗