Intestinal Dominance by Serratia marcescens and Serratia ureilytica 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 < 0.05) and in the first swab compared to the last (26.9% vs. 4.37%, p < 0.05). Nine neonates had extraintestinal detection of 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 < 0.05). (4) Conclusions: Intestinal dominance by Serratia spp. plays a role in outbreaks and extraintestinal spread.

Cultivation and sequencing-free protocol for Serratia marcescens detection and typing

“…It has to be noted that in silico analysis of the designed primers suggested a possible cross-reaction with Serratia ureilytica , a species rarely isolated in hospital context but also able to cause nosocomial outbreaks. 33 Unfortunately, no sample for this species was available in our collection to be tested in vitro .…”

Linking preterm infant gut microbiota to nasograstric enteral feeding tubes: exploring potential interactions and microbial strain transmission

“…Each NEFT of this study remains in place for an average of 48 h, time more than enough for the formation of a complex multispecies biofilm inside these devices (35)(36)(37). The simultaneous presence of relevant nosocomial pathogens in the biofilms formed inside NEFTs within two weeks after birth, poses a threat on the host health (21), since they include the main agents involved in neonatal sepsis (56,(58)(59)(60)(61)(62). In addition, microbes living in complex multispecies biofilms are usually more resistant to antimicrobials and other adverse circumstances because of different mechanisms (63)(64)(65)(66)(67)(68), including an enhanced horizontal transfer of antibiotic resistance genes (69)(70)(71)(72)(73).…”

Validation of a New PCR-Based Screening Method for Prevention of Serratia marcescens Outbreaks in the Neonatal Intensive Care Unit

“…In most cases, this issue was easily overcome by subsequent analysis of a diluted specimen. One other limitation remains: due to sequence similarities, our qPCR detects non-pathogenic S. nematodiphila and S. ureilytica –but this might even be an advantage as NICU outbreaks with other Serratia ssp., including S. ureilytica , have been reported [19, 20].…”