Molecular epidemiology of Staphylococcus aureus in post-earthquake northern Haiti

Int J Infect Dis. 2014 Dec:29:146-51. doi: 10.1016/j.ijid.2014.08.007. Epub 2014 Oct 24.

Abstract

Background: Knowledge of nasal carriage is important in predicting staphylococcal infection, and no information exists regarding the endemicity of Staphylococcus aureus in Haiti.

Methods: We performed a cross-sectional analysis of S. aureus nasal screening in an acute care, a subacute rehabilitation, and a community setting, with a brief medical and epidemiological history. PCR-positive S. aureus screening nasal cultures underwent molecular analysis for spa type, SCCmec type, and virulence genes (Panton-Valentine leukocidin (PVL), toxic shock syndrome toxin (TSST), and arginine catabolic mobile element (ACME)), and were evaluated for antibiotic susceptibility using commercial tests.

Results: Overall carriage rates of 8.4% methicillin-susceptible S. aureus (MSSA) and 2.8% methicillin-resistant S. aureus (MRSA) were identified, with a high rate of tetracycline resistance. TSST and PVL genes were identified in MSSA. MRSA isolates contained no virulence markers. Unique MSSA phenotypes (i.e., linezolid-resistant, vancomycin-sensitive/daptomycin non-susceptible) were identified, as were two PVL-positive ST152 MSSA colonization isolates, previously geographically limited to Africa.

Conclusions: We found a low S. aureus carriage rate with complete vancomycin susceptibility and high tetracycline resistance, which has important public health implications with regard to treatment. Additionally, the finding of PVL-positive MSSA isolates, including the expansion of a previously described limited 'divergent' clone, ST152, warrants further evaluation.

Keywords: Epidemiology; Haiti; Molecular epidemiology; Staphylococcus aureus.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Bacterial Toxins / genetics
  • Cross-Sectional Studies
  • Earthquakes
  • Enterotoxins / genetics
  • Exotoxins / genetics
  • Female
  • Haiti / epidemiology
  • Humans
  • Leukocidins / genetics
  • Male
  • Methicillin Resistance
  • Methicillin-Resistant Staphylococcus aureus / isolation & purification
  • Middle Aged
  • Staphylococcal Infections / epidemiology*
  • Staphylococcal Infections / virology
  • Staphylococcus aureus / drug effects
  • Staphylococcus aureus / genetics*
  • Staphylococcus aureus / isolation & purification
  • Superantigens / genetics
  • Virulence Factors / genetics
  • Young Adult

Substances

  • Bacterial Toxins
  • Enterotoxins
  • Exotoxins
  • Leukocidins
  • Panton-Valentine leukocidin
  • Superantigens
  • Virulence Factors
  • enterotoxin F, Staphylococcal