Project description:Campylobacter jejuni normally grows in the lower intestinal mucus layer as a commensal in avian and animal hosts or as a pathogen in humans. Increasing viscosity of media to physiological levels present in lower intestinal mucus has been observed to increase growth and swimming velocity of WT C. jejuni. Two mutants (DflgV) and (DvidC; DCjj81176_1732) that lack components of the C. jejuni flagellar motor were identified that do not properly modulate swimming velocity in a viscosity-dependent manner. These mutants also have growth and viability defects when grown in standing broth cultures composed of Mueller-Hinton broth at low viscosity (1 cP; no methycellulose) or higher viscosity (40 cP; with methylcellulse). The transcriptome of WT C. jejuni and two mutants lacking FlgV or VidC were analyzed and compared after growth in standing Mueller-Hinton broth cultures of 1 or 40 cP.
Project description:Gene content comparison of control C. jejuni subsp. jejuni strain 11168 which colonizes and causes disease in C57BL/6 IL-10-/- mice versus C. jejuni strains D6844, D6845, D6846, D6847, D6848, D6849, D0121, D0835, D2586, D2600,33560 and NW in the C57BL/6 IL-10-/- mice. Keywords: DNA/DNA comparison
Project description:The species Campylobacter jejuni is naturally competent for DNA uptake; nevertheless, nonnaturally transformable strains do exist. For a subset of strains we previously showed that a periplasmic DNase, encoded by dns, inhibits natural transformation in C. jejuni. In the present study, genetic factors coding for DNase activity in absence of dns were identified. DNA arrays indicated that nonnaturally transformable dns-negative strains contain putative DNA/RNA non-specific endonucleases encoded by CJE0566 and CJE1441 of strain RM1221. These genes are located on C. jejuni integrated element 2 and 4. Expression of CJE0566 and CJE1441 from strain RM1221 and a homologous gene from strain 07479 in DNase-negative Escherichia coli and C. jejuni strains indicated that these genes code for DNases. Genetic transfer of the genes to a naturally transformable C. jejuni strain resulted in a decreased efficiency of natural transformation. Modelling suggests that the C. jejuni DNases belong to the Serratia nuclease family. Overall, the data indicate that the acquisition of prophage encoded DNA/RNA non-specific endonucleases inhibits the natural transformability of C. jejuni through hydrolysis of DNA.
2009-11-14 | GSE18399 | GEO
Project description:Historical Mycobacterium bovis isolates of animal origin, Canada
| PRJNA1089215 | ENA
Project description:Antimicrobial resistance in E. coli isolated from animal origin