Intestinal Dominance by <i>Serratia marcescens</i> and <i>Serratia ureilytica</i> among Neonates in the Setting of an Outbreak

Abstract

(1) Background: We determined the relevance of intestinal dominance by Serratia spp. during a neonatal outbreak over 13 weeks. (2) Methods: Rectal swabs (n = 110) were obtained from 42 neonates. Serratia spp. was cultured from swabs obtained from 13 neonates (Group 1), while the other 29 neonates were culture-negative (Group 2). Total DNA was extracted from rectal swabs, and quantitative PCRs (qPCRs) using Serratia- and 16SrRNA-gene-specific primers were performed. relative intestinal loads (RLs) were determined using ΔΔCt. Clonality was investigated by random amplified polymorphic DNA analysis and whole-genome sequencing. (3) Results: The outbreak was caused by Serratia marcescens during the first eight weeks and Serratia ureilytica during the remaining five weeks. Serratia spp. were detected by qPCR in all Group 1 neonates and eleven Group 2 neonates. RLs of Serratia spp. were higher in Group 1 as compared to Group 2 (6.31% vs. 0.09%, p p Serratia spp.; eight of them were infected. RLs of the patients with extraintestinal spread were higher than the rest (2.79% vs. 0.29%, p Serratia spp. plays a role in outbreaks and extraintestinal spread.

Keywords

• <i>Serratia marcescens</i>
• <i>Serratia ureilytica</i>
• neonatal ward
• intestinal dominance
• qPCR