Project description:Neisseria meningitidis is the leading cause of bacterial meningitis and septicemia worldwide. The novel ST-4821 clonal complex caused several serogroup C meningococcal outbreaks unexpectedly during 2003–2005 in China. We fabricated a whole-genome microarray of Chinese N. meningitidis serogroup C representative isolate 053442 and characterized 27 ST-4821 complex isolates which were isolated from different serogroups using comparative genomic hybridization (CGH) analysis. This paper provides important clues which are helpful to understand the genome composition and genetic background of different serogroups isolates, and possess significant meaning to the study of the newly emerged hyperinvasive lineage. Keywords: comparative genomic hybridization
Project description:Neisseria meningitidis is the leading cause of bacterial meningitis and septicemia worldwide. The novel ST-4821 clonal complex caused several serogroup C meningococcal outbreaks unexpectedly during 2003â2005 in China. We fabricated a whole-genome microarray of Chinese N. meningitidis serogroup C representative isolate 053442 and characterized 27 ST-4821 complex isolates which were isolated from different serogroups using comparative genomic hybridization (CGH) analysis. This paper provides important clues which are helpful to understand the genome composition and genetic background of different serogroups isolates, and possess significant meaning to the study of the newly emerged hyperinvasive lineage. To further understand the genome diversity of ST-4821 complex isolates, CGH analysis was employed to compare the genomic content of 053442 with those of 27 ST-4821 complex isolates which were isolated from 14 provinces of China during 1977â2005.
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 To compare the genome compositions of these menC ST-7 isolates with those of menC ST-4821 isolates, menA ST-7 isolates and menB ST-7 isolates, we performed comparative genomic hybridization (CGH) analysis among 17 N. meningitidis isolates (including two newly identified menC ST-7 isolates) using an updated version of the whole-genome microarray of N. meningitidis serogroup C isolate 053442 .
Project description:Hypermutable P. aeruginosa isolates are prevalent in cystic fibrosis and associated with acute exacerbations of chronic lung infections leading to early death and increased resistance emergence. Achievable epithelial lining fluid concentration-time profiles of meropenem and tobramycin in monotherapy and combination regimens were simulated against two clinical hypermutable P. aeruginosa isolates; CW8 (MICmeropenem=8mg/L, MICtobramycin=8mg/L) and CW44 (MICmeropenem=4mg/L, MICtobramycin=2mg/L) in an 8-day hollow fiber infection model (HFIM). Both isolates were previously characterised with genotypes resembling those of carbapenem- and aminoglycoside-resistant strains. Meropenem at 1 or 2g every 8h (3h infusion) and tobramycin at 5 or 10mg/kg body weight every 24h (0.5h infusion) were studied. Total and resistant bacterial counts were determined. Whole genome sequencing was performed on mutants and whole population samples at 191h, and transcriptomics at 1 and 191h. Mechanism-based modelling of total and resistant populations was informed by the multi-omics analysis. While all regimens against both isolates produced regrowth, the high dose combination synergistically suppressed resistant regrowth against CW8 up to ~96h. The high dose combination provided some killing against CW44, however failed to prevent resistant regrowth. In CW8, mutations emerged during treatment in pmrB, ampR, and multiple efflux pump regulators; in CW44, mutations in pmrB and PBP2 were observed. In CW8, resistance genes mexB and oprM were downregulated by the combination at 1h and coincided with synergistic killing, with differential expression of outer membrane norspermidine and lipopolysaccharide genes at 191h. Mechanism-based modelling incorporating subpopulation and mechanistic synergy successfully characterized the bacterial response of CW8, while mechanistic synergy was not required for CW44. Incorporating information from the multi-omics analyses was instrumental in building the mechanism-based model to describe the bacterial response of the hypermutable isolates, whereas MICs and traditional PK/PD indices could not predict the outcomes of the HFIM.
Project description:Sexual reproduction and recombination are essential for the survival of most eukaryotic populations. Until recently, the impact of these processes on the structure of bacterial populations has been largely overlooked. The advent of large-scale whole-genome sequencing and the concomitant development of molecular tools, such as microarray technology, facilitate the sensitive detection of recombination events in bacteria. These techniques are revealing that bacterial populations are comprised of isolates that show a surprisingly wide spectrum of genetic diversity at the DNA level. Our new awareness of this genetic diversity is increasing our understanding of population structures and of how these affect host?pathogen relationships. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Keywords: Logical Set
2005-10-20 | GSE3479 | GEO
Project description:Whole genome sequencing for bacterial isolates
| PRJNA1129516 | ENA
Project description:Whole genome sequencing and analysis of bacterial isolates from Ireland
Project description:We performed whole genome single nucleotide polymorphism (SNP) based analysis of all available Venezuelan equine encephalitis (VEE) virus antigenic complex genomes and developed a high resolution genome-wide SNP microarray. We used the SNP microarray to analyze a broad panel of VEEV isolates, found excellent concordance between array and sequence based genotypes for previously sequenced strains, and genotyped unsequenced strains.
Project description:Acinetobacter baumannii is often highly resistant to multiple antimicrobials, posing a risk of treatment failure, and colistin is a "last resort" for treatment of the bacterial infection. However, colistin resistance is easily developed when the bacteria are exposed to the drug, and a comprehensive analysis of colistin-mediated changes in colistin-susceptible and -resistant A. baumannii is needed. In this study, using an isogenic pair of colistin-susceptible and -resistant A. baumannii isolates, alterations in morphologic and transcriptomic characteristics associated with colistin resistance were revealed. Whole-genome sequencing showed that the resistant isolate harbored a PmrBL208F mutation conferring colistin resistance, and all other single-nucleotide alterations were located in intergenic regions. Using scanning electron microscopy, it was determined that the colistin-resistant mutant had a shorter cell length than the parental isolate, and filamented cells were found when both isolates were exposed to the inhibitory concentration of colistin. When the isolates were treated with inhibitory concentrations of colistin, more than 80% of the genes were upregulated, including genes associated with antioxidative stress response pathways. The results elucidate the morphological difference between the colistin-susceptible and -resistant isolates and different colistin-mediated responses in A. baumannii isolates depending on their susceptibility to this drug.