Project description:The capsular serotype has long been associated with the virulence of Streptococcus pneumoniae. Here we present an in-depth study of phenotypic and genetic differences between serotype 3 and serogroup 11 S. pneumoniae clinical isolates from both the general and indigenous populations of Australia. Both serotypes/groups included clonally unrelated strains with differences in well-known polymorphic virulence genes, such as nanA and pspA, as demonstrated by multilocus sequence typing and Western blot analysis. Nonetheless, the serotype 3 strains were consistently and significantly more virulent in mice than the serogroup 11 strains. Despite extensive genomic analysis, noncapsular genes common to one serotype/group but not the other were not identified. Nevertheless, following the conversion of a serotype 11A isolate to serotype 3 and subsequent analysis in an intranasal infection model, it was evident that both capsular and noncapsular factors determine the virulence phenotype in mice. However, it appears that these noncapsular factors vary from strain to strain. Data is also available from http://bugs.sgul.ac.uk/E-BUGS-126
Project description:These experiments were performed to show a serogroup conversion in Vibrio cholerae from O1 to O139. For this purpose, V. cholerae O1 WT = A1552 was grown on crab shell fragments to induce natural competence for transformation. Purified DNA (2 ug each) from strain VC73-orf6/7-Kan-A was added after 24h and the cells grown further for 24h. The VC73-orf6/7-Kan-A strain is a ATCC25873 derivative (both O37 serogroup) which harbors a Kanamycin cassette in the O37 region (as part of the operon between orf6 and orf7 w/o own promotor) for better selection. Transformants were selected on LB+Kan plates. Three clones were selected from each experiment and analyzed by microarray hybridization (BioPrime. Array CGH Genomic Labeling from Invitrogen). Two microarray replicates were done per clone. Comparison of A1552 versus VC73-orf6/7-Kan-A is shown as control. A genotyping experiment design type classifies an individual or group of individuals on the basis of alleles, haplotypes, SNP's. Keywords: genotyping_design
Project description:Neisseria meningitidis is a major cause of bacterial meningitis and septicemia worldwide. Seven new serogroup C meningococci were isolated from two provinces of China in January, 2006. Their PorA VR types were P1.20, 9. Multilocus sequence typing results indicated that they all belonged to ST-7. It is a new serogroup C N. meningitidis sequence type clone identified in China. Here we also present the results of a genomic comparison of these isolates with other 15 N. meningitidis serogroup A and B isolates, which belonged to ST-7, based on comparative genomic hybridization analysis. The data described here would be helpful to monitor the spread of this new serogroup C meningococci sequence type clone in China and worldwide. Keywords: comparative genomic hybridization
Project description:These experiments were performed to show a serogroup conversion of Vibrio cholerae from O1 to O139. For this purpose, V. cholerae O1 El Tor (A1552) was grown on crab shell fragments to induce natural competence for transformation. Purified DNA (4 ug each) from strain MO10, an O139 serogroup strain, was added after 24h and the cells were further grown for 24h. After detachment from the crab shell fragments, bacteria were poured into soft-agar and overlaid onto LB plates. Mukerjee's El Tor phage V (a gift of Dr. M.S. Islam) was dropped onto the surface of the bacteria containing soft-agar. The plaques formed by killing non-transformed A1552 cells possessed resistant clones which were picked and further selected for opaque morphotype and agglutination by O139-specific antiserum. Four clones were selected from each independent experiment and analyzed by microarray hybridization (BioPrime. Array CGH Genomic Labeling from Invitrogen). Two microarray replicates were done per clone. Strain Names: ApO139#2 / ApO139#4 / ApO139#6 / ApO139#8 are four clones analyzed after the first experiment; AIIpO139#3 / AIIpO139#4 / AIIpO139#5 / AIIpO139#6 are four clones analyzed after the second independent experiment. Two MA replicates for each clone were done. CGHs of A1552 versus MO10 are provided as control. Keywords: array CGH