Objectives Clinical and epidemiological analysis of Serratia marcescens infections in neonatal units.
Methods Analysis involved eight neonates, three from neonatal units and five from neonatal intensive care units (NICU). In all, from April 2003 to October 2003, 12 S marcescens strains were isolated from different clinical materials: blood, anus, nasopharynx. Genetic analysis of isolates was determined by the pulsed-field gel electrophoresis method using SpeI restriction enzyme.
Results Out of 12 S marcescens isolates, 11 showed identical band patterns and were classified to genetic type A. One strain showed a unique band pattern. Type A strains originated from neonates with acquired infections (two from neonatal units and five from NICU). These strains were isolated once in four babies, twice in two, and three times in one baby. The unique pattern strain was isolated from the neonate hospitalised in a neonatal unit. All infected babies had either low or very low birth weight. Infections were clinically manifested as septicaemia (three cases), generalised infection (four), pneumonia (one).
Conclusions Genetic analysis confirmed the presence of an epidemic clone responsible for infections in neonates. Application of strict sanitary routines resulted in the eradication of S marcescens infections in the units.