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A Heterogeneous Outbreak of Enterobacter cloacae and Serratia marcescens Infections in a Surgical Intensive Care Unit

Published online by Cambridge University Press:  02 January 2015

Grant Dorsey
Affiliation:
Epidemiology and Prevention Interventions Center at San Francisco General Hospital, University of California–San Francisco
Hena T. Borneo
Affiliation:
Epidemiology and Prevention Interventions Center at San Francisco General Hospital, University of California–San Francisco
Sumi J. Sun
Affiliation:
Epidemiology and Prevention Interventions Center at San Francisco General Hospital, University of California–San Francisco
Jennifer Wells
Affiliation:
Epidemiology and Prevention Interventions Center at San Francisco General Hospital, University of California–San Francisco
Lynn Steele
Affiliation:
Epidemiology and Prevention Interventions Center at San Francisco General Hospital, University of California–San Francisco
Kathryn Howland
Affiliation:
Epidemiology and Prevention Interventions Center at San Francisco General Hospital, University of California–San Francisco
Francoise Perdreau-Remington
Affiliation:
Epidemiology and Prevention Interventions Center at San Francisco General Hospital, University of California–San Francisco
David R. Bangsberg*
Affiliation:
Epidemiology and Prevention Interventions Center at San Francisco General Hospital, University of California–San Francisco
*
Epidemiology and Prevention Interventions Center at San Francisco General Hospital, University of California–San Francisco, 1001 Potrero Ave, Building 100, Room 301, San Francisco, CA 94110, db@epi-center.ucsf.edu

Abstract

Objective:

To investigate an outbreak of invasive disease due to Enterobacter cloacae and Serratia marcescens in a surgical intensive care unit (ICU).

Design:

Pulsed-field gel electrophoresis (PFGE) analysis of restriction fragments was used to characterize the outbreak isolate genotypes. A retrospective cohort study of surgical ICU patients was conducted to identify risk factors associated with invasive disease. Unit staffing data were analyzed to compare staffing levels during the outbreak to those prior to and following the outbreak.

Setting:

An urban hospital in San Francisco, California.

Patients:

During the outbreak period, December 1997 through January 1998, there were 52 patients with a minimum ICU stay of ≥72 hours. Of these, 10 patients fit our case definition of recovery of E cloacae or S marcescens from a sterile site.

Results:

PFGE analysis revealed a highly heterogeneous population of isolates. Bivariate analysis of patient-related risk factors revealed duration of central lines, respiratory colonization, being a burn patient, and the use of gentamicin or nafcillin to be significantly associated with invasive disease. Both respiratory colonization and duration of central lines remained statistically significant in a multivariate analysis. Staffing data suggested a temporal correlation between understaffing and the outbreak period.

Conclusions:

Molecular epidemiological techniques provided a rapid means of ruling out a point source or significant cross-contamination as modes of transmission. In this setting, patient-related risk factors, such as respiratory colonization and duration of central lines, may provide a focus for heightened surveillance, infection control measures, and empirical therapy during outbreaks caused by common nosocomial pathogens. In addition, understaffing of nurses may have played a role in this outbreak, highlighting the importance of monitoring staffing levels.

Type
Original Articles
Copyright
Copyright © The Society for Healthcare Epidemiology of America 2000

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References

1. Jarvis, WR, Martone, WJ. Predominant pathogens in hospital infections. J Antimicrob Chemother 1992;29(suppl A):1924.Google Scholar
2. Passaro, DJ, Waring, L, Armstrong, R, Bolding, F, Bouvier, B, Rosenberg, J, et al. Postoperative Serratia marcescens wound infections traced to an out-of-hospital source. J Infect Dis 1997;175:992995.Google Scholar
3. Sanders, WE Jr, Sanders, CC. Enterobacter spp: pathogens poised to flourish at the turn of the century. Clin Microbiol Rev 1997;10:220241.Google Scholar
4. Debast, SB, Melchers, WSG, Voss, A, Hoogkamp-Korstanje, JA, Meis, JF. Epidemiological survey of an outbreak of multiresistant Serratia marcescens by PCR-fingerprinting. Infection 1995;23:267271.Google Scholar
5. Pitout, JD, Sanders, CC, Sanders, WE Jr. Antimicrobial resistance with focus on β-lactam resistance in gram-negative bacilli. Am J Med 1997;103:5159.Google Scholar
6. Ogtrop, ML, van Soeren-Grobben, D, Verbakel-Salomons, EMA, van Boven, CPA Serratia marcescens infections in neonatal departments: description of an outbreak and review of the literature. J Hosp Infect 1997;36:95103.Google Scholar
7. Lacey, SL, Want, SV. An outbreak of Enterobacter cloacae associated with contamination of a blood gas machine. J Infect 1995;30:223226.Google Scholar
8. Mayhall, CG, Lamb, A, Gayle, WE, Haynes, BW. Enterobacter cloacae septicemia in a burn center: epidemiology and control of an outbreak. J Infect Dis 1979;139:166171.Google Scholar
9. Verweij, PE, Van Belkum, A, Melchers, WJ, Voss, A, Hoogkamp-Korstanje, JA, Meis, JF. Interrepeat fingerprinting of third-generation cephalosporin-resistant Enterobacter cloacae isolated during an outbreak in a neonatal intensive care unit. Infect Control Hosp Epidemiol 1995;16:2529.Google Scholar
10. Cimolai, N, Trombley, C, Wensley, D, LeBlanc, J. Heterogeneous Serratia marcescens genotypes from a nosocomial pediatric outbreak. Chest 1997;111:194197.Google Scholar
11. Arlet, G, Rouveau, M, Casin, I, Bouvet, PJ, Lagrange, PH, Philippon, A. Molecular epidemiology of Klebsiella pneumoniae strains that produce SHV-4 β-lactamase and which were isolated in 14 French hospitals. J Clin Microbiol 1994;32:25532558.Google Scholar
12. Maslow, JN, Slutsky, AM, Arbeit, RD. Applications of pulsed-field gel electrophoresis to molecular epidemiology. In: Persing, DH, ed. Diagnostic Molecular Microbiology: Principles and Applications. Washington, DC: American Society for Microbiology; 1993:563572.Google Scholar
13. Tenover, FC, Arbeit, RD, Goering, RV. Interpreting chromosomal DNA restriction patterns produced by pulsed-field gel electrophoresis: criteria for bacterial typing. J Clin Microbiol 1993;33:22332239.Google Scholar
14. Georghiou, PR, Hamill, RJ, Wright, CE, Versalovic, J, Koeuth, T, Watson, DA, et al. Molecular epidemiology of infections due to Enterobacter aerogenes: identification of hospital outbreak-associated strains by molecular techniques. Clin Infect Dis 1995;20:8494.Google Scholar
15. Wenger, PN, Tokars, JI, Brennan, P, Samel, C, Bland, L, Miller, M, et al. An outbreak of Enterobacter hormaechei infection and colonization in an intensive care nursery. Clin Infect Dis 1997;24:12431244.Google Scholar
16. Davin-Regali, A, Saux, P, Bollet, C, Goin, F, De Micco, P. Investigation of outbreaks of Enterobacter aerogenes colonization and infection in intensive care units by random amplification of polymorphic DNA. J Med Microbiol 1996;4:8998.Google Scholar
17. Shi, ZY, Liu, PY, Lau, YT, Lin, YH, Hu, BS. Use of pulse-field gel electrophoresis to investigate an outbreak of Serratia marcescens . J Clin Microbiol 1997;35:325327.Google Scholar
18. Fridkin, SK, Pear, SM, Williamson, TH, Galgiani, JN, Jarvis, WR. The role of understaffing in central venous catheter-associated bloodstream infections. Infect Control Hosp Epidemiol 1996;17:150158.Google Scholar
19. Meier, PA, Carter, CD, Wallace, SE, Hollace, RJ, Pfaller, MA, Herwaldt, LA. A prolonged outbreak of methicillin-resistant Staphylococcus aureus in the burn unit of a tertiary medical center. Infect Control Hosp Epidemiol 1996;17:798802.Google Scholar
20. Jacobson, KL, Cohen, SH, Inciardi, JF, King, JH, Lippert, WE, Iglesias, T, et al. The relationship between antecedent antibiotic use and resistance to extended-spectrum cephalosporins in group I β-lactamase-producing organisms. Clin Infect Dis 1995;21:11071113.Google Scholar
21. Chow, JW, Fine, MJ, Shlaes, DM, Quinn, JP, Hooper, DC, Johnson, MP, et al. Enterobacter bacteremia: clinical features and emergence of antibiotic resistance during therapy. Ann Intern Med 1991;115:585589.Google Scholar