title: Molecular epidemiology of Staphylococcus epidermidis in neonatal intensive care units.
abstract: Late-onset sepsis (LOS) in preterm neonates is increasingly reported to be associated with gut-colonizing Staphylococcus epidermidis. We aimed to describe the molecular epidemiology of S. epidermidis colonizing the gut of neonates hospitalized in two neonatal intensive care units. S. epidermidis from rectal swabs were typed by multilocus variable-number tandem-repeat analysis (MLVA), randomly chosen isolates of predominant MLVA types additionally by multilocus sequence typing. Antimicrobial susceptibility, the presence of icaA, IS256, arginine catabolic mobile element (ACME), agr type, and SCCmec type were determined. Of 276 neonates (38.4%), 106 were colonized with S. epidermidis, yielding a total of 139 isolates (62 in one unit and 77 in another unit). Of the 55 MLVA types identified, the five predominant detected in both units corresponded to sequence type (ST) 2, ST5, and ST59 or its single locus variant ST81 and formed three major MLVA clonal complexes accounting for 74.8% of all isolates. Overall, the prevalence of mecA, icaA, IS256, and ACME was 91.4%, 28.1%, 64%, and 77%, respectively. Of the mecA-positive isolates (n = 127), 43.9% carried SCCmec type IV. Of eight episodes of LOS, four were caused by ST2 and two by ST5. Preventing gut colonization with nosocomial epidemic S. epidermidis in hospitalized neonates could contribute to the prevention of LOS.
authors.affiliation: Department of Microbiology, University of Tartu, Tartu, Estonia.
authors.forename: Hiie
authors.initials: H
authors.lastname: Soeorg
authors.affiliation: Department of Microbiology, University of Tartu, Tartu, Estonia.
authors.forename: Kristi
authors.initials: K
authors.lastname: Huik
authors.affiliation: Department of Microbiology, University of Tartu, Tartu, Estonia.
authors.forename: Ülle
authors.initials: Ü
authors.lastname: Parm
authors.affiliation: Department of Microbiology, University of Tartu, Tartu, Estonia.|Pediatric Intensive Care Unit, Tallinn Children's Hospital, Tallinn, Estonia.
authors.forename: Mari-Liis
authors.initials: ML
authors.lastname: Ilmoja
authors.affiliation: Department of Microbiology, University of Tartu, Tartu, Estonia.|Pediatric Intensive Care Unit, Tartu University Hospital, Tartu, Estonia.
authors.forename: Tuuli
authors.initials: T
authors.lastname: Metsvaht
authors.affiliation: Department of Microbiology, University of Tartu, Tartu, Estonia.
authors.forename: Irja
authors.initials: I
authors.lastname: Lutsar
mesh_terms: D002353:Carrier State / Q000453:epidemiology* / Q000382:microbiology; D005260:Female; D005838:Genotype; D006801:Humans; D007231:Infant, Newborn; D007363:Intensive Care Units, Neonatal; D008297:Male; D008826:Microbial Sensitivity Tests; D018598:Minisatellite Repeats; D017720:Molecular Epidemiology; D058885:Multilocus Sequence Typing; D011446:Prospective Studies; D012007:Rectum / Q000382:microbiology*; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D013212:Staphylococcus epidermidis / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D037521:Virulence Factors / Q000235:genetics
chemical_list: D037521:Virulence Factors
keywords: Staphylococcus epidermidis; colonization; gut; multilocus sequence typing; multilocus variable-number tandem-repeat analysis; neonate