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Molecular Epidemiology of Methicillin–Resistant Staphylococcus Aureus in a Veterans Administration Medical Center

Published online by Cambridge University Press:  02 January 2015

Loreen A. Herwaldt ,
Jean M. Pottinger ,
Stacy Coffman  and
Jean Tjaden
Loreen A. Herwaldt*
Affiliation:
The University of Iowa Hospitals and Clinics, Iowa City, Iowa Department of Internal Medicine, The University of Iowa College of Medicine, Iowa City, Iowa The Veterans Affairs Medical Center, Iowa City, Iowa
Jean M. Pottinger
Affiliation:
The University of Iowa Hospitals and Clinics, Iowa City, Iowa The Veterans Affairs Medical Center, Sioux Falls, South Dakota
Stacy Coffman
Affiliation:
Department of Internal Medicine, The University of Iowa College of Medicine, Iowa City, Iowa
Jean Tjaden
Affiliation:
The Veterans Affairs Medical Center, Sioux Falls, South Dakota
*
C 520-1 GH, The University of Iowa Hospitals and Clinics, Iowa City, IA 52242-1081
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Abstract

Objectives:

To determine whether patients who were colonized or infected with methicillin-resistant Staphylococcus aureus (MRSA) persistently carried the same strain and to identify the extent of strain variation within a population of patients.

Design:

Molecular typing by pulsed-field gel electrophoresis (PFGE) of stored MRSA isolates.

Setting:

A Veterans Administration Medical Center with 288 hospital, 45 intermediate-care, and 75 extended-care beds.

Isolates:

Between January 1991 and March 1993, 91 patients had MRSA identified in routine cultures. One hundred isolates from 57 patients (63%) were available for typing.

Results:

Before 1988, only occasional MRSA isolates were identified. By 1993, 50% of S. aureus isolates from unique patients were resistant to methicillin. PFGE identified 7 MRSA strains, 3 of which were identified in specimens from 1 patient each. The most common strains were SD4 (20 patients), SD1 (12 patients), SD2 (12 patients), and SD5a (5 patients). Twenty patients had 2 or more isolates obtained at least 1 week apart (mean, 30.7 weeks; range, 1 to 102 weeks). Of these patients, 12 were colonized or infected with only one strain (mean time observed, 25.1 weeks; range, 1 to 82 weeks). Eight patients had at least 2 different strains (mean time observed, 39 weeks; range, 2 to 102 weeks).

Conclusion:

Numerous MRSA strains circulated in tiiis endemic setting; 40% of patients observed over time were colonized or infected witii more than one strain. Molecular typing was an essential tool for evaluating the epidemiology of MRSA in this setting.

Type
Original Articles
Information
Infection Control & Hospital Epidemiology , Volume 23 , Issue 9 , September 2002 , pp. 502 - 505
Copyright
Copyright © The Society for Healthcare Epidemiology of America 2002

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References

1.Boyce, JM. Methicillin-resistant Staphylococcus aureus: detection, epidemiology, and control measures. Infect Dis Clin North Am 1989;3:901–913.CrossRefGoogle ScholarPubMed
2.Cohen, SH, Morita, MM, Bradford, M. A seven-year experience with methicillin-resistant Staphylococcus aureus. Am J Med 1991;91:233S–237S.CrossRefGoogle ScholarPubMed
3.Murphy, S, Denman, S, Bennett, RG, Greenough, WB, Lindsay, J, Zelesnick, LB. Methicillin-resistant Staphylococcus aureus colonization in a long-term-care facility. J Am Geriatr Soc 1992;40:213–217.CrossRefGoogle ScholarPubMed
4.Mylotte, JM, Karuza, J, Bentley, DW. Methicillin-resistant Staphylococcus aureus: a questionnaire survey of 75 long-term care facilities in western New York. Infect Control Hosp Epidemiol 1992;13:711–718.CrossRefGoogle ScholarPubMed
5.Strausbaugh, LJ, Jacobson, C, Sewell, DL, Potter, S, Ward, TT. Methicillin-resistant Staphylococcus aureus in extended care facilities: experiences in a Veterans' Affairs nursing home and a review of the literature. Infect Control Hosp Epidemiol 1991;12:36–45.CrossRefGoogle Scholar
6.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;19:1123–1128.CrossRefGoogle ScholarPubMed
7.Maslow, JN, Brecher, S, Gunn, J, Durbin, A, Barlow, MA, Arbeit, RD. Variation and persistence of methicillin-resistant Staphylococcus aureus strains among individual patients over extended periods of time. Eur J Clin Microbiol Infect Dis 1995;14:282–290.CrossRefGoogle ScholarPubMed
8.National Committee for Clinical Laboratory Standards. Performance Standards for Antimicrobial Disk Susceptibility Tests, 6th ed. Approved standard M2-A6. Villanova, PA: National Committee for Clinical Laboratory Standards; 1997.Google Scholar
9.Pfaller, MA, Hollis, RJ, Sader, HS. Chromosomal restriction fragment analysis by pulsed-field gel electrophoresis. In: Isenberg, HD, ed. Clinical Microbiology Procedures Handbook, Supplement 1. Washington, DC: American Society for Microbiology; 1994:10.5.c.1–10.5.c.12.Google Scholar
10.Tenover, FC, Arbeit, R, Archer, G, et al. Comparison of traditional and molecular methods of typing isolates of Staphylococcus aureus. J Clin Microbiol 1994;32:407–415.CrossRefGoogle ScholarPubMed
11.Dice, L. Measures of the amount of ecologic association between species. Ecology 1945;26:297–302.CrossRefGoogle Scholar
12.Williams, REO. Health carriage of Staphylococcus aureus: its prevalence and importance. Bacteriologica Review 1963;27:56–71.CrossRefGoogle Scholar
13.Zierdt, CH. Long-term Staphylococcus aureus carrier state in hospital patients. J Clin Microbiol 1982;16:517–520.CrossRefGoogle ScholarPubMed
14.Roodyn, L. Staphylococcal infections in general practice. BMJ 1954; ii:1322–1325.CrossRefGoogle Scholar
15.Roodyn, L. Recurrent staphylococcal infections and the duration of the carrier state. Journal of Hygiene 1960;58:11–19.CrossRefGoogle ScholarPubMed
16.Hartstein, AI, Phelps, CL, Kwok, RYY, Mulligan, ME. In vivo stability and discriminatory power of methicillin-resistant Staphylococcus aureus typing by restriction endonuclease analysis of plasmid DNA compared with those of other molecular methods. J Clin Microbiol 1995;33:2022–2026.CrossRefGoogle ScholarPubMed