Genome-wide identification of genes required for fitness of group A Streptococcus in human blood.
Infect Immun
; 81(3): 862-75, 2013 Mar.
Article
en En
| MEDLINE
| ID: mdl-23297387
ABSTRACT
The group A streptococcus (GAS) is a strict human pathogen responsible for a wide spectrum of diseases. Although GAS genome sequences are available, functional genomic analyses have been limited. We developed a mariner-based transposon, osKaR, designed to perform Transposon-Site Hybridization (TraSH) in GAS and successfully tested its use in several invasive serotypes. A complex osKaR mutant library in M1T1 GAS strain 5448 was subjected to negative selection in human blood to identify genes important for GAS fitness in this clinically relevant environment. Mutants underrepresented after growth in blood (output pool) compared to growth in rich media (input pool) were identified using DNA microarray hybridization of transposon-specific tags en masse. Using blood from three different donors, we identified 81 genes that met our criteria for reduced fitness in blood from at least two individuals. Genes known to play a role in survival of GAS in blood were found, including those encoding the virulence regulator Mga (mga), the peroxide response regulator PerR (perR), and the RofA-like regulator Ralp-3 (ralp3). We also identified genes previously reported for their contribution to sepsis in other pathogens, such as de novo nucleotide synthesis (purD, purA, pyrB, carA, carB, guaB), sugar metabolism (scrB, fruA), zinc uptake (adcC), and transcriptional regulation (cpsY). To validate our findings, independent mutants with mutations in 10 different genes identified in our screen were confirmed to be defective for survival in blood bactericidal assays. Overall, this work represents the first use of TraSH in GAS to identify potential virulence genes.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Streptococcus pyogenes
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Sangre
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Regulación Bacteriana de la Expresión Génica
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Genoma Bacteriano
Tipo de estudio:
Diagnostic_studies
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Prognostic_studies
Límite:
Humans
Idioma:
En
Revista:
Infect Immun
Año:
2013
Tipo del documento:
Article
País de afiliación:
Estados Unidos