Project description:Epidemiological data indicate that strains MGAS315 and MGAS9887 differ significantly in their capacity to cause necrotizing fasciitis infections. To probe the hypothesis that this difference was associated with differences in gene expression, an expression MA comparison of the strains in exponential phase growth in rich media was conducted. Keywords: strain comparison
Project description:Choriodecidual infection is associated with preterm premature rupture of membranes (pPROM) and preterm birth. MicroRNAs (miRNAs) are small, non-coding RNAs that regulate gene expression and may be involved in the pathway leading to chorioamnion weakening following infection. The study objective was to determine if a miRNA profile in the chorioamnion is associated with Group B Streptococcal infection and membrane weakening.
Project description:Preterm neonates are susceptible to gastrointestinal (GI) disorders such as necrotizing enterocolitis (NEC). Maternal milk, and especially colostrum, protects against NEC via growth promoting, immunomodulatory and antimicrobial factors. The fetal enteral diet, amniotic fluid (AF), contains similar bioactive components and we hypothesized that postnatal AF administration would reduce inflammatory responses and NEC in preterm neonates. Thirty preterm pigs (92% gestation) were delivered by caesarean section and fed total parental nutrition (TPN) for 48 h followed by enteral porcine colostrum (COLOS, n=7), infant formula (FORM, n=13) or formula + porcine AF (AF, n=10). Using a previously validated model of NEC in preterm pigs, we determined the structural, functional, microbiological and immunological responses to AF when administered prior to and after introduction of a suboptimal enteral formula diet. Keywords: Healthy versus inflammed tissues in relation to necrotizing enterocolitis Pigs from each treatment group (COLOS, n=4; FORM, n=6; and AF, n=7) were randomly selected for microarray analysis of frozen distal small intestine samples. The FORM group was further divided into formula-fed healthy pigs (F-HEA, n=3) and formula-fed NEC pigs (F-NEC, n=3) in order to compare sick versus healthy formula fed pigs. Equal amounts of total distal small intestinal RNA from all pigs were pooled to make the reference sample. Samples and reference pool were labelled with Oyster 550 and 650, respectively. The in-house spotted porcine oligonucleotide microarray version 4 (POM4) is a low density microarray consisting of 384 different oligonucleotide probes representing more than 200 different immune related genes.
Project description:To evaluate the effect of genetic background on the immune response to streptococcal infection, eight genetically diverse strains of mice (129/SvImJ, A/J, Balb/cJ, C3H/HeJ, C57BL/6J, Cast/EI, DBA/2J, and FVB/NJ) were infected with three doses of Streptococcus zooepidemicus (500, 5,000, or 50,000 colony forming units - CFUs) by orapharyngeal aspiration. Bacterial clearance was determined by plating out dilutions of homogenized lung tissue and counting the colonies formed after 24 hours of incubation. The mean log10 CFU per ml was calculated for each strain at all timepoints. There was a range of susceptibility between the nine strains at most doses and timepoints (6, 24, and 96 hours). At the lowest dose, the 129/SvImJ and C3H/HeJ strains had significantly higher bacterial counts than five of the other strains at both 24 and 96 hours post infection. In contrast, A/J mice cleared all of the low dose inoculum from their lungs at 96 hours. At the medium dose (5,000 CFUs), the 129/Svlm and the C3H/HeJ continue to be the most susceptible strains. The DBA/2J and the C57BL/6J were the only two strains to show an overall decrease in streptococcal growth from 6 to 96 hours post infection. Following inoculation with the highest dose of Streptococcus, the Balb/cJ strain was significantly more resistant than most other strains at the 6 and 24 hour time points. However, there were no significant differences between strains at the 96 hour time point. The results thus far demonstrate significant host differences in lung response to S. zooepidemicus that strongly suggest a genetic basis for the lung response to bacterial infections.
Project description:We used microarray analysis to investigate if keratinocytes excert an immuno-inflammatory response towards streptococcal M1 protein. Keratinocytes respond to M1 protein by activating pathways to induce the production of inflammatory signaltransducers, AP-1 and NFkB transcription factor subunits, together with inflammatory mediators such as IL-8, CCL20 and IL-1 family proteins etc.