Genotypic Diversity of Staphylococcus aureus α-Hemolysin Gene (hla) and Its Association with Clonal Background: Implications for Vaccine Development

PLoS One. 2016 Feb 11;11(2):e0149112. doi: 10.1371/journal.pone.0149112. eCollection 2016.

Abstract

The α-hemolysin, encoded by the hla gene, is a major virulence factor in S. aureus infections. Changes in key amino acid residues of α-hemolysin can result in reduction, or even loss, of toxicity. The aim of this study was to investigate the diversity of the hla gene sequence and the relationship of hla variants to the clonal background of S. aureus isolates. A total of 47 clinical isolates from China were used in this study, supplemented with in silico analysis of 318 well-characterized whole genome sequences from globally distributed isolates. A total of 28 hla genotypes were found, including three unique to isolates from China, 20 found only in the global genomes and five found in both. The hla genotype generally correlated with the clonal background, particularly the multilocus sequence type, but was not related to geographic origin, host source or methicillin-resistance phenotype. In addition, the hla gene showed greater diversity than the seven loci utilized in the MLST scheme for S. aureus. Our investigation has provided genetic data which may be useful for future studies of toxicity, immunogenicity and vaccine development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms
  • Bacterial Proteins / genetics
  • Bacterial Toxins / genetics*
  • China
  • Genome, Bacterial
  • Genotype
  • Hemolysin Proteins / genetics*
  • Humans
  • Methicillin Resistance
  • Methicillin-Resistant Staphylococcus aureus
  • Multilocus Sequence Typing
  • Mutation
  • Penicillin-Binding Proteins / genetics
  • Phenotype
  • Polymorphism, Single Nucleotide
  • Staphylococcal Infections / microbiology
  • Staphylococcus aureus / genetics*
  • Virulence Factors / genetics

Substances

  • Bacterial Proteins
  • Bacterial Toxins
  • Hemolysin Proteins
  • Penicillin-Binding Proteins
  • Virulence Factors
  • mecA protein, Staphylococcus aureus
  • staphylococcal alpha-toxin

Grant support

YCX recieved a National Research Special Fund for Public Welfare Industry of Health of China (grant number 201402001, http://www.moh.gov.cn/qjjys/s3577/201401/e9f3635e7acb47778225ccb729ffec62.shtml) from the Ministry of Health of China. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.