Project description:Staphylococcus aureus (S. aureus) is a known pathogen able to infect humans and animals. Human S. aureus isolates are often associated with carriage of Sa3int prophages combined with loss of beta-hemolysin production due to gene disruption, whereas animal isolates are positive for beta-hemolysin associated with absence of Sa3int prophages. Sa3int prophages are known to contribute to staphylococcal fitness and virulence in human host by providing human-specific virulence factors encoded on the prophage genome. Strain-specific differences in regard to phage transfer, lysogenization and induction are attributable to yet unknown staphylococcal factors specifically influencing prophage gene expression. In this work we used tagRNA-sequencing approach to specifically search for these unknown host factors and differences in prophage gene expression. For this purpose, we established a workflow revealing the first direct comparison for differential gene expression analysis on two distinct single-lysogenic S. aureus isolates. Further, global gene expression patterns were investigated in two S. aureus isolates upon mitomycin C treatment and compared to uninduced conditions. This provides new insights into the tightly linked host-phage interaction network.
2022-10-03 | GSE214523 | GEO
Project description:Clinical Isolates from Companion Animals to Determine Mechanisms of Antimicrobial Resistance
Project description:Blastocystis is an anaerobic unicellular protozoal parasite infecting the gastrointestinal tract of humans and a wide range of animals. It is one of the most common enteric microorganisms with higher prevalence rates in developing than in developed countries. Feco-oral is the main route of transmission where low socioeconomic conditions, poor hygienic practices, close contact with animals, and drinking contaminated water act as major risk factors. Infection with Blastocystis was demonstrated in both symptomatic and asymptomatic people. For a long period, Blastocystis was considered a commensal organism with no pathogenic role, but recently, many studies linked it to different gastrointestinal symptoms such as nausea, diarrhea, and abdominal pain. Association with irritable bowel syndrome and colorectal cancer was also reported.
This study aims to:
- Identify subtypes of human Blastocystis isolates in Sohag by using RFLP-PCR and provide additional information on the molecular epidemiology of this parasite in our locality.
Project description:An important, but rarely performed, test of Koch’s molecular postulates involves evaluating the capacity of candidate virulence genes to confer pathogenicity in otherwise non-virulent species. Unbiased genomic surveys of avirulent natural isolates might reveal rare variants possessing specific virulence features, which might prove useful in testing their functional sufficiency. Using a custom pan-genome array, we analyzed a panel of avirulent Burkholderia thailandensis (Bt) isolates related to Burkholderia pseudomallei (Bp), the causative agent of the often fatal human and animal disease melioidosis. We report the discovery of variant Bt isolates exhibiting isolated acquisition of a capsular polysaccharide biosynthesis gene cluster (BpCPS), long regarded as an critical species-specific virulence factor essential for Bp mammalian virulence. BpCPS-expressing Bt strains exhibited certain pathogen-related phenotypes including resistance to human complement binding, but did not exhibit enhanced virulence when assessed in two different in vivo animal infection models. Phylogenetic analysis revealed that the BpCPS-expressing Bt strains likely reside within an evolutionary subgroup distinct from the majority of previously-described Bt strains. Our findings suggest that BpCPS acquisition alone is unlikely to fully explain the ability of Bp to colonize humans and animals, highlighting the importance of other collaborating factors in the pathogenesis of mammalian melioidosis.