Detection of methicillin-resistant and methicillin-susceptible Staphylococcus aureus colonization of healthy military personnel by traditional culture, PCR, and mass spectrometry

作者:Shaw Ashley G*; Vento Todd J; Mende Katrin; Kreft Rachael E; Ehrlich Garth D; Wenke Joseph C; Spirk Tracy; Landrum Michael L; Zera Wendy; Cheatle Kristelle A; Guymon Charles; Calvano Tatjana P; Rini Elizabeth A; Tully Charla C; Beckius Miriam L; Murray Clinton K
来源:Scandinavian Journal of Infectious Diseases, 2013, 45(10): 752-759.
DOI:10.3109/00365548.2013.816439

摘要

Background: Methicillin-resistant (MRSA) and methicillin-susceptible (MSSA) Staphylococcus aureus colonization is associated with increased rates of infection. Rapid and reliable detection methods are needed to identify colonization of nares and extra-nare sites, particularly given recent reports of oropharynx-only colonization. Detection methods for MRSA/MSSA colonization include culture, PCR, and novel methods such as PCR/electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS). Methods: We evaluated 101 healthy military members for S. aureus colonization in the nares, oropharynx, axilla, and groin, using CHROMagar S. aureus medium and Xpert SA Nasal Complete PCR for MRSA/MSSA detection. The same subjects were screened in the nares, oropharynx, and groin using PCR/ESI-TOF-MS. Results: By culture, 3 subjects were MRSA-colonized (all oropharynx) and 34 subjects were MSSA-colonized (all 4 sites). PCR detected oropharyngeal MRSA in 2 subjects, which correlated with culture findings. By PCR, 47 subjects were MSSA-colonized (all 4 sites); however, 43 axillary samples were invalid, 39 of which were associated with deodorant/anti-perspirant use (93%, p %26lt; 0.01). By PCR/ESI-TOF-MS, 4 subjects were MRSA-colonized, 2 in the nares and 2 in the oropharynx; however, neither of these correlated with positive MRSA cultures. Twenty-eight subjects had MSSA by PCR/ESI-TOF-MS, and 41 were found to have possible MRSA (S. aureus with mec A and coagulase-negative Staphylococcus (CoNS)). Conclusion: The overall 3% MRSA colonization rate is consistent with historical reports, but the oropharynx-only colonization supports more recent findings. In addition, the use of deodorant/anti-perspirant invalidated axillary PCR samples, limiting its utility. Defining MRSA positivity by PCR/ESI-TOF-MS is complicated by co-colonization of S. aureus with CoNS, which can also carry mecA.

  • 出版日期2013-10