An Outbreak of Serratia marcescens in a Moroccan Neonatal Intensive Care Unit

Abstract

Serratia marcescens (S. marcescens) is an Enterobacteriaceae microorganism that is widespread in the environment, which may be the source of nosocomial infections, rare in the newborn but severe, and often in the form of outbreaks. The aim of our study is to report our experience, during an outbreak of S. marcescens, to show the severity of this germ, with review of the literature. Our study was retrospective, including 8 newborns with S. marcescens nosocomial infection, collected in the neonatal intensive care unit of Mohammed VI University Medical Hospital, during the epidemic period, over a period of 2 months (July and August 2016). The mean gestational age of the cases was 36 weeks of amenorrhea. Boys accounted for 75% of the cases. The average weight was 1853 grams. All the patients were initially placed under empiric antibiotic therapy based on ceftriaxone and gentamicin. The mean duration of nosocomial infection, diagnosed in all cases by blood cultures, was 7 days. The strains of S. marcescens were in 75% of the cases sensitive to the cephalosporins, intermediate sensitivity in 12.5% of cases and resistant in 12.5% of cases. The outcome was fatal in 62.5% of cases. S. marcescens nosocomial infections are often reported on epidemic series, and their eradication is not always easy.

The genus Serratia revisited by genomics

“…These lineages are mainly comprised of recentlysequenced genomes from hospital settings, including a large collection of clinically-derived S. marcescens isolates from the UK that represent the recent emergence of hospital-adapted clones exhibiting recent acquisition of MDR phenotypes 18 . The fact that these lineages of clinically-associated S. marcescens were identified back in the 1970s and 80s shows that the original biochemical characterisation of Serratia captured the emergence of S. marcescens lineages that have subsequently been reported to be associated with human disease many times in recent years 18,19,[50][51][52][53][54][55] . The apparent specialisation of S. marcescens L9 to be a clinically-adapted pathogen is further highlighted by plasmid replicon identification and the types of lineagespecific core genes observed.…”

The phylogenomic landscape of the genus Serratia

“…shows that the original biochemical characterisation of Serratia captured the emergence of S. marcescens lineages that have subsequently been reported to be associated with human disease many times in recent years 18,19,[47][48][49][50][51][52] . The apparent specialisation of S. marcescens L9 to be a clinically-adapted pathogen is further highlighted by plasmid replicon identification and the types of lineage-specific core genes observed.…”

Prevalence and Characterization of Serratia marcescens Isolated from Clinical Bovine Mastitis Cases in Ningxia Hui Autonomous Region of China

“…S. marcescens is an Enterobacteriaceae microorganism that is widespread in the environment, 23 which can cause both clinical and subclinical mastitis outbreaks during the lactation and the dry period in dairy cows. 24 , 25 In this study, S. marcescens was identified in 1.10% of the mastitis milk samples.…”