Skip to main content Accessibility help

Molecular Epidemiology of an Outbreak of Serratia marcescens in a Neonatal Intensive Care Unit

  • Paolo Villari (a1), Margherita Crispino (a2), Alessandra Salvadori (a2) and Alda Scarcella (a3)



To investigate and control a biphasic outbreak of Serratia marcescens in a neonatal intensive care unit (NICU).


Epidemiological and laboratory investigation of the outbreak.


The NICU of the 1,470-bed teaching hospital of the University “Federico II,” Naples, Italy.


The outbreak involved 56 cases of colonization by S marcescens over a 15-month period, with two epidemic peaks of 6 and 3 months, respectively. Fourteen (25%) of the 56 colonized infants developed clinical infections, 50% of which were major (sepsis, meningitis, or pneumonia).


Epidemiological and microbiological investigations, analysis of macrorestriction pattern of genomic DNA through pulsed-field gel electrophoresis (PFGE) of clinical and environmental isolates, and institution of infection control measures.


Analysis of macrorestriction patterns of genomic DNA by PFGE demonstrated that the vast majority of S marcescens isolates, including three environmental strains isolated from two handwashing disinfectants and the hands of a nurse, were of the same clonal type. The successful control of the outbreak was achieved through cohorting of noncolonized infants, isolation of S marcescens-infected and -colonized infants, and an intense educational program that emphasized the need for adherence to glove use and handwashing policies. The NICU remained open to new admissions.


Outbreaks caused by S marcescens are very difficult to eradicate. An infection control program that includes molecular typing of microorganisms and the proper dissemination among staff members of the typing results is likely to be very effective in reducing NICU-acquired infections and in controlling outbreaks caused by S marcescens, as well as other multiresistant bacteria.


Corresponding author

Department of Experimental Medicine and Pathology, University “La Sapienza, ” Viale Regina Elena 324, 00161 Rome, Italy


Hide All
1. McCormack, RC, Kunin, CM. Control of a single source nursery epidemic due to Serratia marcescens . Pediatrics 1966;37:750755.
2. Stamm, WE, Kolff, CA, Munoz Dones, E, Javariz, R, Anderson, RL, Former, JJ III, et al. A nursery outbreak by Serratia marcescens scalp-vein needles as a portal of entry. J Pediatr 1976;89:9699.
3. Cook, LN, Davis, RS, Stover, BH. Outbreak of amikacin-resistant Enterobacteriaceae in an intensive care nursery. Pediatrics 1980;65:264268.
4. Anagnostakis, D, Fitsialos, J, Koutsia, C, Messaritakis, J, Matsaniotis, N. A nursery outbreak of Serratia marcescens infection, evidence of a single source of contamination. Am J Dis Child 1981;135:413414.
5. Christensen, GD, Korones, SB, Reid, L, Bulley, R, McLaughlin, B, Bisno, AL. Epidemic Serratia marcescens in a neonatal intensive care unit: importance of the gastrointestinal tract as a reservoir. Infect Control 1982;3:127133.
6. Scheidt, A, Drusin, LM, Krauss, AN, Machalek, SG. Nosocomial outbreak of resistant Serratia in a neonatal intensive care unit. NY State J Med 1982;82:11881191.
7. Lewis, DA, Hawkey, PM, Watts, JA, Speller, DCE, Primavesi, RJ, Fleming, PJ, et al. Infection with netilmicin resistant Serratia marcescens in a special care baby unit. BMJ 1983;287:17011705.
8. Duggan, TG, Leng, RA, Hancock, BM, Cursons, RT. Serratia marcescens in a newborn unit-microbiological features. Pathology 1984;16:189191.
9. Montanaro, D, Grasso, GM, Annino, I, de Ruggiero, N, Scarcella, A, Schioppa, F. Epidemiological and bacteriological investigation of Serratia marcescens epidemic in a nursery and in a neonatal intensive care unit. J Hyg (Camb) 1984;93:6778.
10. Smith, PJ, Brookfield, DSK, Shaw, DA, Gray, J. An outbreak of Serratia marcescens infection in a neonatal unit. Lancet 1984;1:151153.
11. Newport, MT, John, JF, Michael, YM, Levkoff, AH. Endemic Serratia marcescens infection in a neonatal intensive care nursery associated with gastrointestinal colonization. Pediatr Infect Dis 1985;4:160167.
12. Wake, C, Lees, H, Cull, AB. The emergence of Serratia marcescens as a pathogen in a newborn unit. Aust Pediatr J 1986;22:323326.
13. Braver, DJ, Hauser, GJ, Berns, L, Siegman-Ingra, Y, Muhlbauer, B. Control of a Serratia marcescens outbreak in a maternity hospital. J Hosp Infect 1987;10:129137.
14. Bollmann, R, Halle, E, Sokolowska-Kohler, W, Grauel, EL, Buchholz, P, Hare, I, et al. Nosocomial infections due to Serratia marcescens—clinical findings, antibiotic susceptibility patterns and fine typing. Infection 1989;17:294300.
15. Zaidi, M, Sifuentes, J, Bobadilla, M, Muncada, D, Ponce de Leon, S. Epidemic of Serratia marcescens bacteremia and meningitis in a neonatal unit in Mexico City. Infect Control Hosp Epidemiol 1989;10:1420.
16. McGeer, A, Low, DE, Penner, J, Ng, J, Goldman, C, Simor, AE. Use of molecular typing to study the epidemiology of Serratia marcescens . J Clin Microbiol 1990;28:5558.
17. Pegues, DA, Arathoon, EG, Samayoa, B, Del Valle, GT, Anderson, RL, Riddle, CF, et al. Epidemic gram-negative bacteria in a neonatal intensive care unit in Guatemala. Am J Infect Control 1994;22:163171.
18. Miranda, G, Kelly, C, Solorzano, F, Leanos, B, Coria, R, Patterson, JE. Use of pulsed-field gel electrophoresis typing to study an outbreak of infection due to Serratia marcescens in a neonatal intensive care unit. J Clin Microbiol 1996;34:31383141.
19. Archibald, LK, Corl, A, Shah, B, Schulte, M, Arduino, MJ, Aguero, S, et al. Serratia marcescens outbreak associated with extrinsic contamination of 1% chloroxylenol soap. Infect Control Hosp Epidemiol 1997;18:704709.
20. van Ogtrop, ML, van Zoeren-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.
21. Campbell, JR, Zaccaria, E, Mason, EO Jr, Baker, CJ. Epidemiological analysis defining concurrent outbreaks of Serratia marcescens and methicillin-resistant Staphylococcus aureus in a neonatal intensive-care unit. Infect Control Hosp Epidemiol 1998;19:924928.
22. Berthelot, P, Grattard, F, Amerger, C, Frery, MC, Lucht, F, Pozzetto, B, et al. Investigation of a nosocomial outbreak due to Serratia marcescens in a maternity hospital. Infect Control Hosp Epidemiol 1999;20:233236.
23. Hoyen, C, Rice, L, Conte, S, Jacobs, MR, Walsh-Sukys, M, Toltzis, P. Use of real time pulsed field gel electrophoresis to guide interventions during a nursery outbreak of Serratia marcescens infection. Pediatr Infect Dis J 1999;18:357360.
24. Gaynes, RP, Horan, TC. Surveillance of nosocomial infections. In: Mayhall, CG, ed. Hospital Epidemiology and Infection Control. Baltimore, MD: Williams & Wilkins Co; 1996:10171031.
25. Villari, P, Iacuzio, L, Torre, I, Scarcella, A. Molecular epidemiology as an effective tool in the surveillance of infections in the neonatal intensive care unit. J Infect 1998;37:274281.
26. Villari, P, Sarnataro, C, Iacuzio, L. Molecular epidemiology of Staphylococcus epidermidis in a neonatal intensive care unit over a three-year period. J Clin Microbiol 2000;38:17401746.
27. National Committee for Clinical Laboratory Standards. Performance Standards for Antimicrobial Disk Susceptibility Tests. Approved Standard M2-A5. 5th ed. Villanova, PA: NCCLS; 1993.
28. National Committee for Clinical Laboratory Standards. Performance Standards for Antimicrobial Susceptibility Testing. Sixth Informational Supplement: M100-S6. Villanova, PA: NCCLS; 1995.
29. Legrand, P, Fournier, G, Buré, A, Jarlier, V, Nicolas, MH, Decré, D, Duval, J, Philippon, A. Detection of extended broad-spectrum β-lactamases in Enterobacteriaceae in four French hospitals. Eur J Clin Microbiol Infect Dis 1989;8:527529.
30. Tenover, FC, Arbeit, RD, Goering, RU, Mickelsen, PA, Murray, BE, Persing, DH, Swaminathan, B. Interpreting chromosomal DNA restriction patterns produced by pulsed-field gel electrophoresis: criteria for bacterial strain typing. J Clin Microbiol 1995;33:22332239.
31. National Nosocomial Infections Surveillance (NNIS) System report, data summary from January 1990-May 1999, issued June 1999. Am J Infect Control 1999;27:520532.
32. Shi, ZY, Iiu, PYF, Lau, Yj, Lin, YH, Hu, BS. Use of pulsed-field gel electrophoresis to investigate an outbreak of Serratia marcescens . J Clin Microbiol 1997;35:325327.
33. Iivermore, DM. β-lactamases in laboratory and clinical resistance. Clin Microbiol Rev 1995;8:557584.
34. Coudron, PE, Moland, ES, Sanders, CC. Occurrence and detection of extended spectrum β-lactamases in members of the family Enterobacteriaceae at a Veterans Medical Center: seek and you may find. J Clin Microbiol 1997;35:25932597.
35. Palucha, A, Mikiewicz, B, Hryniewicz, W, Gniadkowsky, M. Concurrent outbreaks of extended-spectrum p-lactamase-producing organisms of the family Enterobacteriaceae in a Warsaw hospital. J Antimicrob Chemother 1999;44:489499.

Related content

Powered by UNSILO

Molecular Epidemiology of an Outbreak of Serratia marcescens in a Neonatal Intensive Care Unit

  • Paolo Villari (a1), Margherita Crispino (a2), Alessandra Salvadori (a2) and Alda Scarcella (a3)


Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed.