Staphylococcus aureus nasal carriage, virulence traits, antibiotic resistance mechanisms, and genetic lineages in healthy humans in Spain, with detection of CC398 and CC97 strains

  1. Lozano, C. 1
  2. Gómez-Sanz, E. 1
  3. Benito, D. 1
  4. Aspiroz, C. 2
  5. Zarazaga, M. 1
  6. Torres, C. 1
  1. 1 Universidad de La Rioja
    info

    Universidad de La Rioja

    Logroño, España

    ROR https://ror.org/0553yr311

  2. 2 Laboratorio Microbiología, Hospital Royo Villanova, Zaragoza, Spain
Revista:
International Journal of Medical Microbiology

ISSN: 1438-4221

Año de publicación: 2011

Volumen: 301

Número: 6

Páginas: 500-505

Tipo: Artículo

DOI: 10.1016/J.IJMM.2011.02.004 SCOPUS: 2-s2.0-79960279690 WoS: WOS:000294584300006 GOOGLE SCHOLAR

Otras publicaciones en: International Journal of Medical Microbiology

Resumen

S. aureus nasal carriage was investigated in 278 healthy humans, determining the antibiotic resistance mechanisms, virulence traits, and genetic lineages of recovered isolates. Nasal samples were cultured in specific media for S. aureus and methicillin-resistant S. aureus (MRSA) recovery. S. aureus was detected in 53 of 278 nasal samples (19.1%): MRSA was found in one sample (0.4%) and methicillin-susceptible S. aureus (MSSA) in the remaining 52 samples. The MRSA isolate was typed as ST1649-t701- agrI-SCC. mec-IVc and only exhibited resistance to beta-lactams. A high diversity of spa types (n= 37) was identified among the 52 MSSA, identifying 5 new spa-types. Multi-locus sequence typing (MLST) typing was performed in 30 selected MSSA, detecting 16 different sequence types, 2 of them being new. MSSA strains presented agr types I (30.2%), II (30.2%), III (34%), and IV (5.6%). Eleven strains showed erythromycin resistance and harbored different combinations of erm(A), erm(B), erm(C), erm(T), and msr(A) genes. Two strains exhibited ciprofloxacin resistance, and one of them presented amino acid changes in GyrA and GrlA proteins. The presence of 28 genes encoding staphylococcal toxins was investigated by PCR in all 53 S. aureus isolates. The toxic shock syndrome toxin 1 (TSST-1) gene was detected in 15 MSSA isolates (11 of them typed within the clonal complex CC30) and the gene of exfoliative toxin A in 2 strains. Different combinations of enterotoxin genes were identified among S. aureus strains. None of the S. aureus isolates harbored the Panton-Valentine leukocidin gene. Two MSSA presented the sequence-type ST398 [harboring erm(T) gene], and 2 additional isolates were typed as ST97. Interestingly, MSSA CC398 and CC97 isolates were detected. These clonal complexes are associated with food-producing animals. © 2011 Elsevier GmbH.