An outbreak due to Serratia marcescens in a neonatal intensive care unit typed by 2-day pulsed field gel electrophoresis protocol.
BACKGROUND
Serratia marcescens is a well-recognized nosocomial pathogen. The objective of the study was to describe typing results using a rapid pulsed field gel electrophoresis (PFGE) protocol and infection control measures during an outbreak of Serratia marcescens in a 24-bed, referral, neonatal intensive care unit (NICU) of a tertiary-care pediatric hospital.


METHODS
Two patients with S. marcescens sepsis were identified in the NICU. Health care personnel of the unit were requested to reinforce infection control measures. Active surveillance was established to detect infected and/or colonized patients and environmental and staff reservoirs. Infected and colonized patients were cohorted on one side of the unit; admissions to NICU were limited. Isolates were typed with a short 2-day pulsed-field gel electrophoresis (PFGE) protocol.


RESULTS
Thirty three patients were exposed during a period of 20 days. Ten S. marcescens isolates were obtained from six patients, in two from blood culture and in three from stool culture; a single clone was identified in four. S. marcescens was not isolated from environmental or staff cultures.


CONCLUSIONS
PFGE results were obtained in 2 days, infection control measures were reinforced, outbreak was promptly interrupted, and the NICU remained opened.
Departamento de Infectología, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, Mexico. guadalumiranda@infosel.net.mx
Guadalupe
G
Miranda-Novales
Blanca
B
Leaños-Miranda
Rita
R
Díaz-Ramos
Lourdes
L
González-Tejeda
Leoncio
L
Peregrino-Bejarano
Raúl
R
Villegas-Silva
Fortino
F
Solórzano-Santos
D015373:Bacterial Typing Techniques; D003428:Cross Infection; D016521:Electrophoresis, Gel, Pulsed-Field / Q000379:methods*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007363:Intensive Care Units, Neonatal; D016868:Serratia Infections / Q000453:epidemiology*; D012706:Serratia marcescens / Q000145:classification* / Q000235:genetics