Detection of methicillin-resistant and methicillin-susceptible Staphylococcus aureus colonization of healthy military personnel by traditional culture, PCR, and mass spectrometry. (October 2013)

• Record Type: Journal Article
• Authors: 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.
• Is Part Of: Scandinavian journal of infectious diseases. Volume 45:Number 10(2013:Oct.)
• Page Start: 752
• Page End: 759
• Publication Date: 2013-10
• Subjects: Communicable diseases -- Periodicals; Infection -- Periodicals; 616.9
• DOI: 10.3109/00365548.2013.816439
• Languages: English
• ISSNs: 0036-5548

Abstract

<abstract> <title>Abstract</title> <p> <italic>Background:</italic> 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). <italic>Methods:</italic> 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. <italic>Results:</italic> 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%, <italic>p</italic> < 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 <italic>mec</italic>A and coagulase-negative Staphylococcus (CoNS)). <italic>Conclusion:</italic> 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 <italic>mec</italic>A.</p> </abstract>