Insights into Alpha-Hemolysin (Hla) Evolution and Expression among Staphylococcus aureus Clones with Hospital and Community Origin

Autor: Jesper Bo Nielsen, Susanne Rohde, Ana Tavares, Kristian Schønning, Henrik Westh, Hermínia de Lencastre, Maria Miragaia, Kit Boye, Ana Cristina Paulo
Jazyk: angličtina
Rok vydání: 2014
Předmět:
RNAIII
Epidemiology
lcsh:Medicine
Gene Expression
Pathogenesis
medicine.disease_cause
Pathology and Laboratory Medicine
Hemolysin Proteins
Medicine and Health Sciences
lcsh:Science
Promoter Regions
Genetic
Phylogeny
Genetics
0303 health sciences
Cross Infection
Multidisciplinary
Hemolysin
Staphylococcal Infections
Community-Acquired Infections
Staphylococcus aureus
Medical Microbiology
Genetic Epidemiology
Research Article
DNA
Bacterial
Sequence analysis
Virulence Factors
Bacterial Toxins
Human leukocyte antigen
Microbial Sensitivity Tests
Biology
Microbiology
Polymorphism
Single Nucleotide
Infectious Disease Epidemiology
03 medical and health sciences
medicine
Humans
Allele
Gene
Microbial Pathogens
030304 developmental biology
Evolutionary Biology
Base Sequence
030306 microbiology
lcsh:R
Biology and Life Sciences
Sequence Analysis
DNA
Genetic Polymorphism
Multilocus sequence typing
lcsh:Q
Methicillin Resistance
Population Genetics
Multilocus Sequence Typing
Zdroj: PLoS ONE
PLoS ONE, Vol 9, Iss 7, p e98634 (2014)
ISSN: 1932-6203
Popis: Background Alpha-hemolysin (Hla) is a major virulence factor in the pathogenesis of Staphylococcus aureus infection, being active against a wide range of host cells. Although hla is ubiquitous in S. aureus, its genetic diversity and variation in expression in different genetic backgrounds is not known. We evaluated nucleotide sequence variation and gene expression profiles of hla among representatives of hospital (HA) and community-associated (CA) S. aureus clones. Methods 51 methicillin-resistant S. aureus and 22 methicillin-susceptible S. aureus were characterized by PFGE, spa typing, MLST and SCCmec typing. The internal regions of hla and the hla promoter were sequenced and gene expression was assessed by RT-PCR. Results Alpha-hemolysin encoding- and promoter sequences were diverse, with 12 and 23 different alleles, respectively. Based on phylogenetic analysis, we suggest that hla may have evolved together with the S. aureus genetic background, except for ST22, ST121, ST59 and ST93. Conversely, the promoter region showed lack of co-evolution with the genetic backgrounds. Four non-synonymous amino acid changes were identified close to important regions of hla activity. Amino acid changes in the RNAIII binding site were not associated to hla expression. Although expression rates of hla were in general strain-specific, we observed CA clones showed significantly higher hla expression (p = 0.003) when compared with HA clones. Conclusion We propose that the hla gene has evolved together with the genetic background. Overall, CA genetic backgrounds showed higher levels of hla expression than HA, and a high strain-to-strain variation of gene expression was detected in closely related strains.
Databáze: OpenAIRE
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