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

• Published in: PloS one Vol. 11; no. 2; p. e0149112
• Main Authors: Xiao, Meng, Zhao, Rui, Zhang, Qi, Fan, Xin, O'Sullivan, Matthew V N, Li, Dong-Fang, Wang, Xin-Ying, Wu, Hong-Long, Kong, Fanrong, Xu, Ying-Chun
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 11-02-2016; Public Library of Science (PLoS)
• Subjects: Algorithms; Amino acid sequence; Amino acids; Antimicrobial agents; Bacterial Proteins - genetics; Bacterial Toxins - genetics; Biology and Life Sciences; China; Clinical isolates; Cloning; Deoxyribonucleic acid; DNA; Earth Sciences; Ecology and Environmental Sciences; Electric power; Epidemiology; Gene sequencing; Genome, Bacterial; Genomes; Genomics; Genotype; Genotypes; Gram-positive bacteria; Hemolysin Proteins - genetics; Histocompatibility antigen HLA; Humans; Immunization; Immunogenicity; Infectious diseases; Laboratories; Medicine and Health Sciences; Methicillin; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Multilocus Sequence Typing; Mutation; Penicillin-Binding Proteins - genetics; People and Places; Phenotype; Pneumonia; Polymorphism, Single Nucleotide; Research and Analysis Methods; Staphylococcal Infections - microbiology; Staphylococcus aureus; Staphylococcus aureus - genetics; Staphylococcus infections; Toxicity; Vaccine development; Vaccines; Virulence; Virulence factors; Virulence Factors - genetics; China; Beijing China; Australia; New South Wales Australia
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0149112

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.