Project description:The purpose of the experiments is to understand transcriptional reprogramming in roots of halophyte Schrenkiella parvula (S. parvula) that may contribute to its high salt tolerance. Root materials were harvested from S. parvula seedlings grown on agar plates with ½ strength Murashige-Skoog (½MS) medium including vitamins for 4 days and transferred to ½MS medium supplemented with 0mM or 175mM NaCl for 0h, 3h, 24h or 48h.
Project description:We investigated the specific interactions of the most dominant bacterial CF-pathogen, Pseudomonas aeruginosa, and the anaerobic bacterium Veilllonella parvula, that has been recovered at comparable cell numbers in the respiratory tract of CF patients. We used our recently established in-vivo murine tumor model to investigate mutual influences of the two pathogens during a biofilm-associated infection process. We found that although P. aeruginosa and V. parvula colonized distinct niches within the tumor, in mice that were co-infected with both bacterial species significant higher cell numbers of P. aeruginosa were recovered from the tumor tissue. Concordantly, in vivo transcriptional profiling implied that the presence of V. parvula supports P. aeruginosa growth at the infected host site, and the higher P. aeruginosa load correlated with clinical deterioration.
Project description:In the oral biofilm, the mitis streptococci are among the first group of organisms to colonize the tooth surface. Their proliferation is thought to be an important factor required for antagonizing the growth of cariogenic species such as Streptococcus mutans. In this study, we used a 3-species mixed culture to demonstrate that another ubiquitous early colonizing species, Veillonella parvula, could greatly impact the competitive outcome of a mixed culture of S. mutans and S. gordonii. Transcriptome analysis further revealed that S. mutans responds differentially to its friend (V. parvula) and foe (S. gordonii). In the mixed culture with S. gordonii, all but one S. mutans sugar uptake and metabolic genes were down-regulated, while genes for alternative energy source utilization and H2O2 tolerance were up-regulated, resulting in a slower but persistent growth. In contrast, when cultured with V. parvula, S. mutans grew equally well or better than in monoculture and exhibited relatively few changes within its transcriptome. When V. parvula was introduced into the mixed culture of S. mutans and S. gordonii, it rescued the growth inhibition of S. mutans. In this 3-species environment, S. mutans increased the expression of genes required for the uptake and metabolism of minor sugars, while genes required for oxidative stress tolerance were down-regulated. We conclude that the major factors affecting the competition between S. mutans and S. gordonii are carbohydrate utilization and H2O2 resistance. The presence of V. parvula in the tri-species culture mitigates these two major factors and allows S. mutans to proliferate, despite the presence of S. gordonii.
2011-05-01 | GSE28259 | GEO
Project description:Quercus parvula var. shrevei Genomic Resources
Project description:Streptococcus mutans was grown for 48 h in a biofilm in the absence (single species) and in the presence (dual species) of Veillonella parvula. In addition V. parvula single species 48 h biofilms were grown, to be used as a control. RNA was harvested from all types of biofilms and the transcript levels of the two types of biofilms containing S. mutans were compared with the use of S. mutans microarrays. V. parvula RNA was hybridized to S. mutans microarrays as a control for possible cross-hybridisation.
Project description:We investigated the specific interactions of the most dominant bacterial CF-pathogen, Pseudomonas aeruginosa, and the anaerobic bacterium Veilllonella parvula, that has been recovered at comparable cell numbers in the respiratory tract of CF patients. We used our recently established in-vivo murine tumor model to investigate mutual influences of the two pathogens during a biofilm-associated infection process. We found that although P. aeruginosa and V. parvula colonized distinct niches within the tumor, in mice that were co-infected with both bacterial species significant higher cell numbers of P. aeruginosa were recovered from the tumor tissue. Concordantly, in vivo transcriptional profiling implied that the presence of V. parvula supports P. aeruginosa growth at the infected host site, and the higher P. aeruginosa load correlated with clinical deterioration. We cultivated P. aeruginosa PA14 and V. parvula DSM No.:2008 in mono- and co-cultures in vivo using an established murine tumor model. Corresponding in vitro samples were generated under anaerobe growth conditions.