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A Blinded Comparison of Three Laboratory Protocols for the Identification of Patients Colonized With Methicillin-Resistant Staphylococcus aureus

  • Michael Gardam (a1), James Brunton (a1), Barbara Willey (a2), Allison McGeer (a2), Donald Low (a2) and John Conly (a1)...

Abstract

Objective:

To compare three laboratory screening protocols for the detection of methicillin-resistant Staphylococcus aureus (MRSA) from surveillance specimens (mannitol-salt agar containing 2 μg/mL of oxacillin [MSA-2], mannitol-salt agar containing 4 μg/mL of oxacillin [MSA-4], and a broth-containing protocol as recommended by the American Society for Microbiology [M-ASM]).

Design:

Blinded comparative laboratory study and cost analysis.

Setting:

University-affiliated microbiology laboratory.

Methods:

Outcome measurements included rate of detection of MRSA-positive specimens and patients, turnaround time, and media and technologist costs. All MRSA culture swabs obtained from any patient site from November 1998 to April 1999 were included.

Results:

The M-ASM protocol detected between 19.1% and 32.0% more MRSA-positive specimens and between 13.3% and 23.3% more MRSA-positive patients per surveillance event than the MSA-4 and MSA-2 protocols, respectively. There was no difference in positive-culture reporting time between the M-ASM and MSA-4 protocols. The broth-containing protocol was 2- to 2.5-fold more expensive than the simpler protocols, taking into account media and laboratory personnel costs.

Conclusions:

It remains to be determined whether it is cost beneficial for a hospital to adopt the M-ASM, as the potential cost of MRSA transmission from unidentified MRSA-colonized patients is unknown. A broth-containing protocol should be considered the gold standard in future studies examining newer MRSA screening protocols.

Copyright

Corresponding author

200 Elizabeth St, NUW 13-132, Toronto General Hospital, University Health Network, Toronto, Ontario M5G 2C4, Canada

References

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1. Hartstein, AI, Mulligan, ME. Methicillin-resistant Staphylococcus aureus . In: Mayhall, CG, ed. Hospital Epidemiology and Infection Control. Baltimore, MD: Williams & Wilkins; 1996:290306.
2. Sautter, RL, Brown, WJ, Mattman, LH. The use of a selective staphylococcal broth vs direct plating for the recovery of Staphylococcus aureus . Infect Control Hosp Epidemiol 1988;9:204205.
3. Cookson, BD, Webster, M, Phillips, I. Control of epidemic methicillin-resistant Staphylococcus aureus . Lancet 1987;1:696.
4. Van Ogtrop, ML. Effect of broth enrichment cultures on ability to detect carriage of Staphylococcus aureus . Antimicrobial Agents Chemother 1995;39:2169.
5. Davies, S, Zadik, PM. Comparison of methods for the isolation of methicillin-resistant Staphylococcus aureus . J Clin Pathol 1997;50:257258.
6. Gorss, EB. Prospective, focused surveillance for oxacillin-resistant Staphylococcus aureus . In: Isenberg, HD, ed. Clinical Microbiology Procedures Handbook. Washington, DC: American Society for Microbiology Press; 1992:11.15.111.15.2.
7. Murakami, K, Minamide, W, Wada, K, Nakamura, E, Teraoka, H, Watanabe, S. Identification of methicillin-resistant strains of staphylococci by polymerase chain reaction. J Clin Microbiol 1991;29:22402244.
8. Jernigan, JA, Climence, MA, Stott, GA, Titus, MG, Alexander, CH, Palumbo, CM, et al. Control of methicillin-resistant Staphylococcus aureus at a university hospital: one decade later. Infect Control Hosp Epidemiol 1995;16:686696.
9. Jernigan, JA, Titus, MG, Groschel, DHM, Getchell-White, SI, Farr, BM. Effectiveness of contact isolation during a hospital outbreak of methicillin-resistant Staphylococcus aureus . Am J Epidemiol 1996;143:496504.
10. Cookson, BD. Selective staphylococcal broth. J Clin Microbiol 1990;28:23802381.
11. Sanford, MD, Widmer, AF, Bale, MJ, Jones, RN, Wenzel, RP. Efficient detection and long-term persistence of the carriage of methicillin-resistant Staphylococcus aureus . Clin Infect Dis 1994;19:11231128.
12. Thompson, RL, Cabezudo, I, Wenzel, RP. Epidemiology of nosocomial infections caused by methicillin-resistant Staphylococcus aureus . Ann Intern Med 1982;92:309317.
13. Papia, G, Louie, M, Tralla, A, Johnson, C, Collins, V, Simor, AE. Screening high-risk patients for methicillin-resistant Staphylococcus aureus on admission to the hospital: is it cost effective? Infect Control Hosp Epidemiol 1999;20:473477.
14. Kennedy, C, Weinwurm, D, Rappoccio, M, Burt, J, Garcia, M, Dedier, H, et al. Reduction of nosocomial MRSA occurrence at the Toronto Hospital: effects of intervention or natural history? Presented at the Community and Hospital Infection Control Association Conference; May 31-June 2, 1999; Moncton, New Brunswick, Canada.
15. Kim, T, Simor, AE, Oh, PI. The economic impact of methicillin-resistant Staphylococcus aureus (MRSA) in Canadian hospitals. Infect Control Hosp Epidemiol 2001;22:99104.
16. Teare, EL, Barrett, SP. Stop the ritual of tracing colonised people. BMJ 1997;314:665666.

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