Evolution of nasal carriage of methicillin-resistant coagulase-negative staphylococci in a remote population

Antimicrob Agents Chemother. 2012 Jan;56(1):315-23. doi: 10.1128/AAC.00547-11. Epub 2011 Nov 7.

Abstract

Nasal carriage of methicillin-resistant coagulase-negative staphylococci (MR-CoNS) is highly prevalent in community subjects, but its dynamic has been little investigated. Nasal swabbing was performed in 2006 and 2008 in 154 Amerindians living isolated in French Guiana. MR-CoNS strains were identified and characterized by non-β-lactam susceptibility testing and staphylococcal cassette chromosome mec element (SCCmec) typing, characterizing the associations of ccr and mec gene complex allotypes, and for MR Staphylococcus epidermidis (MRSE), multilocus variable number of tandem repeats analysis (MLVA) was used. The impact of sociodemographic and medical characteristics on the persistence of MR-CoNS carriage was assessed by bivariate analysis. Prevalence of MR-CoNS carriage was 50.6% in 2006 and 46.8% in 2008. The 274 MR-CoNS isolates, including S. epidermidis (n = 89, 62 MLVA patterns), Staphylococcus haemolyticus (n = 78), and Staphylococcus hominis (n = 72), exhibited 41 distinct ccr and mec gene complex associations. Persistent carriage (in 2006 and 2008), intermittent carriage (either in 2006 or 2008), and noncarriage were documented in 25.3, 47.4, and 27.3% of the participants, respectively. Persistent carriage of a given MRSE isolate was rarely observed (n = 8 isolates). Furthermore, no epidemiological factor, including antibiotic exposure, was associated with persistent carriage. The high diversity of MRSE clones and their ccr and mec gene complex associations contrasted with the high carriage rates in this isolated community, which might reflect the occurrence of SCCmec rearrangement and the generation of new MR-CoNS strains.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Anti-Bacterial Agents / administration & dosage
  • Anti-Bacterial Agents / therapeutic use
  • Bacterial Typing Techniques
  • Carrier State
  • Chromosomes, Bacterial
  • Coagulase / deficiency
  • Coagulase / genetics*
  • Female
  • French Guiana / epidemiology
  • Genes, Bacterial
  • Genetic Linkage
  • Genetic Variation
  • Humans
  • Male
  • Methicillin Resistance / drug effects
  • Methicillin Resistance / genetics*
  • Middle Aged
  • Nose / microbiology*
  • Polymerase Chain Reaction
  • Prevalence
  • Staphylococcal Infections / drug therapy
  • Staphylococcal Infections / epidemiology
  • Staphylococcal Infections / microbiology*
  • Staphylococcus epidermidis / drug effects
  • Staphylococcus epidermidis / genetics*
  • Staphylococcus epidermidis / isolation & purification
  • Staphylococcus haemolyticus / drug effects
  • Staphylococcus haemolyticus / genetics*
  • Staphylococcus haemolyticus / isolation & purification
  • Staphylococcus hominis / drug effects
  • Staphylococcus hominis / genetics*
  • Staphylococcus hominis / isolation & purification

Substances

  • Anti-Bacterial Agents
  • Coagulase