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Genome Sequence of a Highly Virulent pvl-positive Vancomycin-intermediate-resistant Staphylococcus aureus Sequence

Raiane C Chamon1, Lucas M Marques1, Jorge Timenetsky1

  • 11Departamento de Patologia, Faculdade de Medicina, Universidade Federal Fluminense, Niterói, Brazil; 2Laboratório de Infecção Hospitalar, Departamento de Microbiologia Médica, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; 3Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Bahia, Brazil; 4Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil; 5Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; 6Laboratório de Bacteriologia e Imunologia Clínica, Departamento de Análises Clínicas e Toxicológicas, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.

Current Genomics
|July 14, 2020
PubMed
Abstract

Insights

This study sequenced the genome of a Panton-Valentine Leukocidin (PVL)-positive, Vancomycin-Intermediate-Resistant Staphylococcus aureus (VISA) strain from Brazil. The findings reveal numerous virulence factors, suggesting increased pathogenicity and spread of this lineage in hospitals.

Area of Science:

  • Microbiology
  • Genomics
  • Infectious Diseases

Background:

  • Panton-Valentine Leukocidin (PVL)-producing Staphylococcus aureus strains are linked to various diseases.
  • The USA1100 lineage of PVL-positive community-associated methicillin-resistant S. aureus (CA-MRSA) has recently emerged in Brazilian hospitals.

Purpose of the Study:

  • To perform whole-genome sequencing of a PVL-positive, Vancomycin-Intermediate-Resistant S. aureus (VISA) isolate from Rio de Janeiro, Brazil.

Main Methods:

  • Whole-genome sequencing using the HiSeq 2500 platform.
  • Genome and plasmid annotation and analysis using RAST.
  • Quantitative reverse transcription PCR (qRT-PCR) to compare pvl gene expression.

Main Results:

  • The isolate contained two distinct PVL-encoding phages, including a PVL variant (lukF-PV.2 and lukS-PV.2).
  • The genome exhibited numerous virulence determinants, including serine-protease genes, enterotoxins (egc), immune evasion cluster (IEC), adhesion proteins, and the ica operon.
  • The PVL mRNA expression was five times higher than in the USA300/ST8 reference strain, with detected point mutations in vraS, tcaA, and tcaB.

Conclusions:

  • This is the first genome sequence of a VISA isolate with two pvl-associated genes.
  • The identified virulence factors may enhance the fitness and pathogenicity of the USA1100/ST30 lineage.
  • These findings have implications for the understanding and control of S. aureus spread in Brazilian hospitals.
Keywords:
MRSAS. aureusUSA1100/ST30VISApvl-positivevirulence

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