Serratia marcescens Colonization in a Neonatal Intensive Care Unit Has Multiple Sources, with Sink Drains as a Major Reservoir

Abstract

The bacterium Serratia marcescens is an important opportunistic human pathogen that thrives in many environments, can become multidrug resistant, and is often involved in nosocomial outbreaks in neonatal intensive care units (NICU). We evaluated the role of sinks during five suspected S. marcescens outbreaks in a NICU.

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

“…The bacterium is able to survive on various surfaces, including soap, and to rapidly spread among hospital patients, causing large nosocomial outbreaks, particularly in NICUs. 16 , 27 , 28 , 29 , 30 , 31 , 32 S. marcescens mainly colonize the environment (soil, plants, and animals) and recent genomic studies revealed that the nosocomial S. marcescens infections are mostly caused by a specific lineage of the bacterium (here called “Infectious clone”). 3 , 6 , 7 Considering the lethality of the bacterium, its fast-spreading capability and the existence of a strictly infection-associated lineage, a fast and precise detecting/typing method is required to establish effective infection control strategies in hospitals to prevent and to limit outbreaks.…”

“…WGS remains the gold standard for the typing of the S. marcescens infection-associated lineage, and other high throughput sequencing methods such as HiSST proven to be successful in typing S. marcescens . 15 , 16 However, the time needed to carry out the sequencing may represent an important drawback. Indeed, this species is able to spread very rapidly among patients and can exploit different sources to grow in the hospital environment.…”

“… 14 Another recently proposed method, named high-throughput short sequence typing scheme (HiSST), allows for the differentiation of S. marcescens clones both in pure culture and in environmental samples. 15 , 16 However, although this method is effective, it relies on sequencing. Despite the high precision in the discrimination of bacterial clones, sequencing-based typing methods (e.g., HiSST and WGS-based typing) are laborious, time-consuming and expensive.…”

High-Throughput Short Sequence Typing Schemes for Pseudomonas aeruginosa and Stenotrophomonas maltophilia Pure Culture and Environmental DNA

“…Strain differentiation primarily arises from the presence or absence of genes rather than nucleotide polymorphisms, indicating extensive genomic plasticity largely attributed to frequent horizontal gene transfers [ 25 , 60 , 61 ]. HiSST is a robust genotyping tool that provides highly reliable predictions for assessing clonality between strains [ 13 , 62 ]. However, in cases where two strains exhibit identical HiSST profiles, it is highly recommended to use WGS, especially for epidemiological investigations involving P. aeruginosa [ 63 ].…”

A workflow for the detection of antibiotic residues, measurement of water chemistry and preservation of hospital sink drain samples for metagenomic sequencing

“…Hospitals represent a major site for the emergence and dissemination of multi-drug resistant (MDR) pathogens, such as carbapenemase-producing and extendedspectrum β-lactamase (ESBL)-producing Enterobacterales (CPE and ESBL-E, respectively), particularly in critical care units [5][6][7]. These MDR pathogens can colonise healthcareassociated (HCA) environmental reservoirs such as hospital sinks and contribute to healthcare-associated infections (HAIs), with many studies linking HAIs to sink drains [8][9][10],…”