Microevolution of group A streptococci in vivo: capturing regulatory networks engaged in sociomicrobiology, niche adaptation, and hypervirulence.

2.50
Hdl Handle:
http://hdl.handle.net/10033/120545
Title:
Microevolution of group A streptococci in vivo: capturing regulatory networks engaged in sociomicrobiology, niche adaptation, and hypervirulence.
Authors:
Aziz, Ramy K; Kansal, Rita; Aronow, Bruce J; Taylor, William L; Rowe, Sarah L; Kubal, Michael; Chhatwal, Gursharan S; Walker, Mark J; Kotb, Malak
Abstract:
The onset of infection and the switch from primary to secondary niches are dramatic environmental changes that not only alter bacterial transcriptional programs, but also perturb their sociomicrobiology, often driving minor subpopulations with mutant phenotypes to prevail in specific niches. Having previously reported that M1T1 Streptococcus pyogenes become hypervirulent in mice due to selection of mutants in the covRS regulatory genes, we set out to dissect the impact of these mutations in vitro and in vivo from the impact of other adaptive events. Using a murine subcutaneous chamber model to sample the bacteria prior to selection or expansion of mutants, we compared gene expression dynamics of wild type (WT) and previously isolated animal-passaged (AP) covS mutant bacteria both in vitro and in vivo, and we found extensive transcriptional alterations of pathoadaptive and metabolic gene sets associated with invasion, immune evasion, tissue-dissemination, and metabolic reprogramming. In contrast to the virulence-associated differences between WT and AP bacteria, Phenotype Microarray analysis showed minor in vitro phenotypic differences between the two isogenic variants. Additionally, our results reflect that WT bacteria's rapid host-adaptive transcriptional reprogramming was not sufficient for their survival, and they were outnumbered by hypervirulent covS mutants with SpeB(-)/Sda(high) phenotype, which survived up to 14 days in mice chambers. Our findings demonstrate the engagement of unique regulatory modules in niche adaptation, implicate a critical role for bacterial genetic heterogeneity that surpasses transcriptional in vivo adaptation, and portray the dynamics underlying the selection of hypervirulent covS mutants over their parental WT cells.
Affiliation:
Research Services, Veterans Affairs Medical Center, Memphis, Tennessee, United States of America. ramy.aziz@salmonella.org
Citation:
Microevolution of group A streptococci in vivo: capturing regulatory networks engaged in sociomicrobiology, niche adaptation, and hypervirulence. 2010, 5 (4):e9798 PLoS ONE
Journal:
PloS one
Issue Date:
2010
URI:
http://hdl.handle.net/10033/120545
DOI:
10.1371/journal.pone.0009798
PubMed ID:
20418946
Type:
Article
Language:
en
ISSN:
1932-6203
Appears in Collections:
Publications of Dept. Medizinische Mikrobiologie (MMIK)

Full metadata record

DC FieldValue Language
dc.contributor.authorAziz, Ramy Ken
dc.contributor.authorKansal, Ritaen
dc.contributor.authorAronow, Bruce Jen
dc.contributor.authorTaylor, William Len
dc.contributor.authorRowe, Sarah Len
dc.contributor.authorKubal, Michaelen
dc.contributor.authorChhatwal, Gursharan Sen
dc.contributor.authorWalker, Mark Jen
dc.contributor.authorKotb, Malaken
dc.date.accessioned2011-01-28T09:23:00Z-
dc.date.available2011-01-28T09:23:00Z-
dc.date.issued2010-
dc.identifier.citationMicroevolution of group A streptococci in vivo: capturing regulatory networks engaged in sociomicrobiology, niche adaptation, and hypervirulence. 2010, 5 (4):e9798 PLoS ONEen
dc.identifier.issn1932-6203-
dc.identifier.pmid20418946-
dc.identifier.doi10.1371/journal.pone.0009798-
dc.identifier.urihttp://hdl.handle.net/10033/120545-
dc.description.abstractThe onset of infection and the switch from primary to secondary niches are dramatic environmental changes that not only alter bacterial transcriptional programs, but also perturb their sociomicrobiology, often driving minor subpopulations with mutant phenotypes to prevail in specific niches. Having previously reported that M1T1 Streptococcus pyogenes become hypervirulent in mice due to selection of mutants in the covRS regulatory genes, we set out to dissect the impact of these mutations in vitro and in vivo from the impact of other adaptive events. Using a murine subcutaneous chamber model to sample the bacteria prior to selection or expansion of mutants, we compared gene expression dynamics of wild type (WT) and previously isolated animal-passaged (AP) covS mutant bacteria both in vitro and in vivo, and we found extensive transcriptional alterations of pathoadaptive and metabolic gene sets associated with invasion, immune evasion, tissue-dissemination, and metabolic reprogramming. In contrast to the virulence-associated differences between WT and AP bacteria, Phenotype Microarray analysis showed minor in vitro phenotypic differences between the two isogenic variants. Additionally, our results reflect that WT bacteria's rapid host-adaptive transcriptional reprogramming was not sufficient for their survival, and they were outnumbered by hypervirulent covS mutants with SpeB(-)/Sda(high) phenotype, which survived up to 14 days in mice chambers. Our findings demonstrate the engagement of unique regulatory modules in niche adaptation, implicate a critical role for bacterial genetic heterogeneity that surpasses transcriptional in vivo adaptation, and portray the dynamics underlying the selection of hypervirulent covS mutants over their parental WT cells.en
dc.language.isoenen
dc.titleMicroevolution of group A streptococci in vivo: capturing regulatory networks engaged in sociomicrobiology, niche adaptation, and hypervirulence.en
dc.typeArticleen
dc.contributor.departmentResearch Services, Veterans Affairs Medical Center, Memphis, Tennessee, United States of America. ramy.aziz@salmonella.orgen
dc.identifier.journalPloS oneen
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