Hostname: page-component-78c5997874-lj6df Total loading time: 0 Render date: 2024-11-19T22:00:15.009Z Has data issue: false hasContentIssue false

DNA Typing and Control of Methicillin-Resistant Staphylococcus aureus at Two Affiliated Hospitals

Published online by Cambridge University Press:  02 January 2015

Alan I. Hartstein*
Affiliation:
Division of Infectious Diseases and the Department of Medicine, Indiana University Medical Center, Indianapolis, Indiana Infection Control/Epidemiology Laboratory, Indiana University Medical Center, Indianapolis, Indiana Department of Infection Control/Epidemiology, Indiana University Medical Center, Indianapolis, Indiana
Ann M. LeMonte
Affiliation:
Infection Control/Epidemiology Laboratory, Indiana University Medical Center, Indianapolis, Indiana
Pamela K.L. Iwamoto
Affiliation:
Department of Infection Control/Epidemiology, Indiana University Medical Center, Indianapolis, Indiana
*
Department of Infection Control/Epidemiology, Wishard Memorial Hospital, 1001 W 10th St, Ott Bldg 211, Indianapolis, IN 46202

Abstract

Objective:

To describe control of endemic and outbreak-related methicillin-resistant Staphylococcus aureus (MRSA) at two affiliated hospitals.

Design:

Prospective surveillance of patients with MRSA. Disposable gloves were used by all staff having direct contact with the affected patient or his immediate environment, and patient isolates were typed by pulsedfield gel electrophoresis (PFGE) of genomic DNA. Surveillance and PFGE typing were used concurrently to identify possible nosocomial outbreaks, confirm or refute cross-infection, and support a need for additional outbreak control interventions.

Setting:

A university hospital (Hospital A) and a university-affiliated public hospital (Hospital B).

Participants:

Patients with MRSA colonization or infection over an 18-month interval (June 1993-November 1994).

Intervention:

Proper handwashing and gloving practices were reemphasized with staff following confirmation of outbreaks.

Results:

Hospital A had 60 community-acquired and 48 nosocomial cases of MRSA. Two small outbreaks (affecting a total of seven patients) and two pseudo-outbreaks were identified. Hospital B had 36 community-acquired and 22 nosocomial cases of MRSA. Only one outbreak affecting five patients occurred. All outbreaks ended shortly after staff meetings that emphasized ongoing and extremely careful handwashing and gloving when caring for identified patients. The majority of nosocomial cases at both hospitals were not related epidemiologically or had isolates with unique PFGE types. Pseudo-outbreaks were confirmed by demonstrating that isolates from epidemiologically related cases (by time and clinical service or hospital unit) had different PFGE types. Hospital A cases had 39 different PFGE types, and Hospital B cases had 31 different PFGE types.

Conclusion:

MRSA in hospitals, including outbreaks identified by prospective surveillance and confirmed by PFGE typing, can be controlled by minimal special precautions and interventions. This is possible despite the continuous admission of patients with MRSA from the community. PFGE typing is useful to confirm outbreaks and pseudo-outbreaks, demonstrate differences among epidemiologically unrelated isolates, and substantiate the efficacy of MRSA control programs within hospitals.

Type
Original Articles
Copyright
Copyright © The Society for Healthcare Epidemiology of America 1997

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Report of a combined working party of the Hospital Infection Society and British Society for Antimicrobial Chemotherapy. Revised guidelines for the control of epidemic methicillin-resistant Staphylococcus aureus . J Hosp Infect 1990;16:351377.Google Scholar
2. Mulligan, ME, Murray-Leisure, KA, Ribner, BS, et al. Methicillin-resistant Staphylococcus aureus: a consensus review of the microbiology, pathogenesis, and epidemiology with implications for prevention and management. Am J Med 1993;94:313328.Google Scholar
3. Boyce, JM, Jackson, MM, Pugliese, G, et al. Methicillin-resistant Staphylococcus aureus (MRSA): a briefing for acute care hospitals and nursing facilities. Infect Control Hosp Epidemiol 1994;15:105113.CrossRefGoogle ScholarPubMed
4. Lugeon, C, Blanc, DS, Wenger, A, Francioli, P. Molecular epidemiology of methicillin-resistant Staphylococcus aureus at a low-incidence hospital over a four-year period. Infect Control Hosp Epidemiol 1995;16:260267.Google Scholar
5. Linnemann, CC Jr, Moore, P, Staneck, JL, Pfaller, MA. Reemergence of epidemic methicillin-resistant Staphylococcus aureus in a general hospital associated with changing staphylococcal strains. Am J Med 1991;91(suppl 3B):238S244S.Google Scholar
6. Trilla, A, Nettleman, MD, Hollis, RJ, Frederickson, M, Wenzel, RP, Pfaller, MA. Restriction endonuclease analysis of plasmid DNA from methicillin-resistant Staphylococcus aureus: clinical application over a three-year period. Infect Control Hosp Epidemiol 1993;14:2935.Google Scholar
7. Embil, J, Ramotar, K, Romance, L, et al. Methicillin-resistant Staphylococcus aureus in tertiary care institutions on the Canadian prairies 1990-1992. Infect Control Hosp Epidemiol 1994;15:646651.Google ScholarPubMed
8. Layton, MC, Hierholzer, WJ, Patterson, JE. The evolving epidemiology of methicillin-resistant Staphylococcus aureus at a university hospital. Infect Control Hosp Epidemiol 1995;16:1217.CrossRefGoogle ScholarPubMed
9. Hartstein, AI, Denny, MA, Morthland, VH, LeMonte, AM, Pfaller, MA. Control of methicillin-resistant Staphylococcus aureus in a hospital and an intensive care unit. Infect Control Hosp Epidemiol 1995;16:405411.CrossRefGoogle Scholar
10. Hartstein, AI. Improved understanding and control of nosocomial methicillin-resistant Staphylococcus aureus: are we overdoing it? Infect Control Hosp Epidemiol 1995;16:257259.Google Scholar
11. Back, NA, Linnemann, CC Jr, Pfaller, MA, Staneck, JL, Morthland, V. Recurrent epidemics caused by a single strain of erythromycin-resistant Staphylococcus aureus . JAMA 1993;270:13291333.Google Scholar
12. Dice, LR. Measures of the amount of ecologic association between species. Ecology 1945;26:297302.Google Scholar
13. Hall, LMC, Jordens, JZ, Wang, F. Methicillin-resistant Staphylococcus aureus from China characterized by digestion of total DNA with restriction enzymes. Epidemiol Infect 1989;103:183192.Google Scholar
14. Li, WH. Simple method for constructing phylogenetic trees from distance matrices. Proc Natl Acad Sci USA 1981;78:10851089.CrossRefGoogle ScholarPubMed
15. Garner, JS, Jarvis, WR, Emori, TG, Horan, TC, Hughes, JM. CDC definitions for nosocomial infections, 1988. Am J Infect Control 1991;19:1935.Google Scholar
16. Simmons, B, Bryant, J, Neiman, K, Spencer, L, Arheart, K. The role of handwashing in prevention of endemic intensive care unit infections. Infect Control Hosp Epidemiol 1990;11:589594.Google Scholar
17. Rimland, D, Roberson, B. Gastrointestinal carriage of Methicillin-resistant Staphylococcus aureus . J Clin Microbiol 1986;24:137138.Google Scholar
18. Walsh, TJ, Vlahov, D, Hansen, SL, et al. Prospective microbiologic surveillance in control of nosocomial methicillin-resistant Staphylococcus aureus . Infect Control 1987;87:714.CrossRefGoogle Scholar
19. Rao, N, Jacobs, S, Joyce, L. Cost-effective eradication of an outbreak of methicillin-resistant Staphylococcus aureus in a community teaching hospital. Infect Control Hosp Epidemiol 1988;9:255260.Google Scholar
20. Mulligan, ME, Arbeit, RD. Epidemiologic and clinical utility of typing systems for differentiating among strains of Methicillin-resistant Staphylococcus aureus . Infect Control Hosp Epidemiol 1991;12:2028.Google Scholar
21. Tenover, FC, Arbeit, R, Archer, G, et al. Comparison of traditional and molecular methods of typing isolates of Staphylococcus aureus. J Clin Microbiol 1994;32:407415.Google Scholar
22. Arbeit, RD. Laboratory procedures for the epidemiologic analysis of microorganisms. In: Murray, PR, Baron, EJ, Pfaller, MA, Tenover, FC, Yolken, RH, eds. Manual of Clinical Microbiology. 6th ed. Washington, DC: American Society for Microbiology; 1995:190208.Google Scholar
23. Struelens, MJ, Deplano, A, Godard, C, Maes, N, Serruys, E. Epidemiologic typing and delineation of genetic relatedness of methicillin-resistant Staphylococcus aureus by macrorestriction analysis of genomic DNA by using pulsed-field gel electrophoresis. J Clin Microbiol 1992;30:25992605.Google Scholar
24. Branchini, MLM, Morthland, VH, Tresoldi, AT, Nowansky, AV, Dias, MBS, Pfaller, MA. Application of genomic DNA subtyping by pulsed field gel electrophoresis and restriction enzyme analysis of plasmid DNA to characterize methicillin-resistant Staphylococcus aureus from two nosocomial outbreaks. Diagn Microbiol Infect Dis 1993;17:275281.Google Scholar
25. Tenover, FC, Arbeit, RD, Goering, RV, et al. Interpreting chromosomal DNA restriction patterns produced by pulsed-field gel electrophoresis: criteria for bacterial strain typing. J Clin Microbiol 1995;33:22332239.CrossRefGoogle ScholarPubMed
26. Kreiswirth, B, Kornblum, J, Arbeit, RD, et al. Evidence for a clonal origin of methicillin resistance in Staphylococcus aureus . Science 1993;259:227230.CrossRefGoogle ScholarPubMed
27. 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;33:20222026.Google Scholar
28. Johnson, S, Gerding, DN, Olson, MM, et al. Prospective, controlled study of vinyl glove use to interrupt Clostridium difficile nosocomial transmission. Am J Med 1990;88:137140.Google Scholar
29. Slaughter, S, Hayden, MK, Nathan, C, et al. A comparison of the effect of universal use of gloves and gowns with that of glove use alone on acquisition of vancomycin-resistant enterococci in a medical intensive care unit. Ann Intern Med 1996;125:448456.Google Scholar
30. Chetchotisakd, P, Phelps, CL, Hartstein, AI. Assessment of bacterial cross-transmission as a cause of infections in patients in intensive care units. Clin Infect Dis 1994;18:929937.Google Scholar