Dynamics of acquisition and loss of carriage of Staphylococcus aureus strains in the community: The effect of clonal complex - 06/04/14
Summary |
Background |
Staphylococcus aureus nasal carriage increases infection risk. However, few studies have investigated S. aureus acquisition/loss over >1 year, and fewer still used molecular typing.
Methods |
1123 adults attending five Oxfordshire general practices had nasal swabs taken. 571 were re-swabbed after one month then every two months for median two years. All S. aureus isolates were spa-typed. Risk factors were collected from interviews and medical records.
Results |
32% carried S. aureus at recruitment (<1% MRSA). Rates of spa-type acquisition were similar in participants S. aureus positive (1.4%/month) and negative (1.8%/month, P = 0.13) at recruitment. Rates were faster in those carrying clonal complex (CC)15 (adjusted (a)P = 0.03) or CC8 (including USA300) (aP = 0.001) at recruitment versus other CCs. 157/274 (57%) participants S. aureus positive at recruitment returning ≥12 swabs carried S. aureus consistently, of whom 135 carried the same spa-type. CC22 (including EMRSA-15) was more prevalent in long-term than intermittent spa-type carriers (aP = 0.03). Antibiotics transiently reduced carriage, but no other modifiable risk factors were found.
Conclusions |
Both transient and longer-term carriage exist; however, the approximately constant rates of S. aureus gain and loss suggest that ‘never’ or truly ‘persistent’ carriage are rare. Long-term carriage varies by strain, offering new explanations for the success of certain S. aureus clones.
Le texte complet de cet article est disponible en PDF.Keywords : Staphylococcus aureus, Molecular epidemiology, Colonisation, spa-typing, Carriage duration
Plan
☆ | Presentation at previous meetings – Presented as poster at: (1) ICAAC, Boston, 2010. (2) IDweek, San Diego, 2012. |
☆☆ | This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
Vol 68 - N° 5
P. 426-439 - mai 2014 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
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