Project description:Streptococcus suis is a major pig pathogen as well as an emerging zoonotic pathogen. We studied the generic and adaptive resistance response of S. suis upon exposure to sub-lethal concentrations of the human cathelicidin LL-37. We aimed to search for inducible mechanisms of resistance to AMPs as well as induction of virulence gene expression upon exposure to AMPs, in order to gain insights into host-derived factors that might mediate S. suis pathogenesis.
Project description:Streptococcus suis is an important emerging worldwide pig pathogen and zoonotic agent with rapid evolution of virulence and drug resistance. Licochalcone A, used in traditional Chinese medicine, exhibits antimicrobial, antioxidant and anti-inflammatory activities. Herein, a whole-genome DNA microarray was used to investigate the global transcriptional regulation of Streptococcus suis 05ZYH33 treated by subinhibitory concentration of licochalcone A. 132 genes were differentially regulated upon liochalcone A treatment, including 78 genes up-regulated and 54 genes down-regulated which included many central biological functions such as metabolism, transcription and translation. We tried to investigate the antimicrobial mechanism of licochalcone A in the aspect of bacterial cell cycle control. Our analysis indicated that licochalcone A might inhibit the growth of S. suis by controlling the replication initiation and cell division through amino acid metabolism. A cDNA microarray imprinted with 2156 genes representing about 98% of Streptococcus suis serotype 2 genome was used for transcriptome analysis. For two-sample (reference vs. test) microarray hybridization, four independent bacterial cultures from each condition were prepared as biological replicates for RNA isolation. Four dual-fluorescence-labeled cDNA probes were prepared to hybridize with four slides, respectively. Pairwise comparisons were made using dye swaps to avoid labeling bias. A ratio of mRNA levels (test/reference) was calculated for each gene. Significant changes of gene expression were identified with the SAM software. After the SAM analysis, only genes with at least 2-fold changes in expression were collected for further analysis.
Project description:Streptococcus suis is an important emerging worldwide pig pathogen and zoonotic agent with rapid evolution of virulence and drug resistance. Licochalcone A, used in traditional Chinese medicine, exhibits antimicrobial, antioxidant and anti-inflammatory activities. Herein, a whole-genome DNA microarray was used to investigate the global transcriptional regulation of Streptococcus suis 05ZYH33 treated by subinhibitory concentration of licochalcone A. 132 genes were differentially regulated upon liochalcone A treatment, including 78 genes up-regulated and 54 genes down-regulated which included many central biological functions such as metabolism, transcription and translation. We tried to investigate the antimicrobial mechanism of licochalcone A in the aspect of bacterial cell cycle control. Our analysis indicated that licochalcone A might inhibit the growth of S. suis by controlling the replication initiation and cell division through amino acid metabolism.
Project description:Identification of Genes and Genomic Islands Correlated with High Pathogenicity through Tilling Microarray-Based Comparative Genomics in S. suis. Streptococcus suis is an important zoonotic pathogen that can cause meningitis and sepsis in both pigs and humans. S. suis isolates have been categorized into groups of different levels of pathogenicity, with sequence type (ST) ST1 clonal complex strains having a higher degree of virulence than other STs. However, the genetic basis of the differences in pathogenicity is still poorly understood. In this study, a comprehensive genomic comparison of 31 S. suis strains from different clinical sources with the genome sequence of the high pathogenicity (HP) strain GZ1 was conducted using NimbleGen’s tilling microarray platform.
Project description:Identification of Genes and Genomic Islands Correlated with High Pathogenicity through Tilling Microarray-Based Comparative Genomics in S. suis. Streptococcus suis is an important zoonotic pathogen that can cause meningitis and sepsis in both pigs and humans. S. suis isolates have been categorized into groups of different levels of pathogenicity, with sequence type (ST) ST1 clonal complex strains having a higher degree of virulence than other STs. However, the genetic basis of the differences in pathogenicity is still poorly understood. In this study, a comprehensive genomic comparison of 31 S. suis strains from different clinical sources with the genome sequence of the high pathogenicity (HP) strain GZ1 was conducted using NimbleGenM-bM-^@M-^Ys tilling microarray platform. Comparative genomic analysis on the 31 S. suis strains of different serotypes and ST types through tilling arrays.
Project description:Streptococcus suis is a major pig pathogen as well as an emerging zoonotic pathogen. In a previous study (Zaccaria et al. Plos One DOI: 10.1371/journal.pone.0099394) we identified the natural pheromone-induced competence system of S. suis. To identify the mechanisms enabling competence, gene expression analysis of bacteria induced or not for competence, and in presence or absence of exogenous DNA, was assessed at 5, 15 and 45 minutes after pheromone addition. The transcriptomes showed how competence was induced and eventually shut down, and which metabolic pathways were repressed or induced when competence was active or shut down.
Project description:Streptococcus suis is an important zoonotic pathogen that can cause meningitis and sepsis in both pigs and humans. In this study,we evaluated the genetic difference of 40 Streptococcus suis strains belonging to various sequence types by comparative genomic hybridization to identify genes associated with the variation in pathogenicity using NimbleGen’s tilling microarray platform. Application of Comparative Phylogenomics to Identify Genetic Differences Relating to Pathogenicity of Streptococcus suis
Project description:A collection of 61 Salmonella enterica serovar Typhimurium (S. Typhimurium) of animal and human origin, matched as closely as possible by phage type, antimicrobial resistance pattern and place / time of isolation, and sourced from farms or hospitals in Scotland, were analysed by antimicrobial susceptibility testing, phage typing, pulsed field gel electrophoresis (PFGE), plasmid profiling and DNA microarrays. PFGE of all 61 isolates revealed ten PFGE profiles, which clustered by phage type and antibiotic resistance pattern, with human and animal isolates distributed between PFGE profiles. Analysis of 23 representative S. Typhimurium strains hybridised to a composite Salmonella DNA microarray identified a small number of specific regions of genome variation between different phage types and PFGE profiles. These variable regions of DNA were typically located within prophage-like elements. Simple PCR assays were subsequently designed to discriminate between different isolates from the same geographical region.
2007-06-09 | E-SGRP-6 | biostudies-arrayexpress
Project description:16S Sequencing of faecal porcine microbiota in german pig farms