title: The mother as most important risk factor for colonization of very low birth weight (VLBW) infants with extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E).
abstract: OBJECTIVE
  This study aimed to determine the prevalence of and risk factors for colonization with extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) and methicillin-resistant Staphylococcus aureus (MRSA) in very low birth weight (VLBW; <1500 g) infants and their mothers.
  
  
  METHODS
  This investigation was conducted in the perinatal centre at the Charité Berlin between May 2012 and June 2013. VLBW infants and their mothers were screened for colonization with ESBL-E and MRSA. Demographic and clinical data were obtained from the German nationwide surveillance system for nosocomial infections in VLBW infants (NEO-KISS) and used to perform univariate and multivariate analyses.
  
  
  RESULTS
  Of 209 VLBW infants, 12 (5.7%) were colonized with ESBL-E. Eighteen of 209 (8.6%) ESBL-E-tested neonates were related to an ESBL-E-positive mother. Univariate analysis, strain typing and multivariate analysis (OR 7.4, 95% CI 2.1-26.7, P = 0.002) identified an ESBL-E-positive mother and maternal-neonatal transmission as a main source of colonization. The prevalence of MRSA was 2.3% (5 of 221) among VLBW infants. One of the 221 (0.5%) MRSA-tested neonates was related to an MRSA-positive mother. No risk factors for transmission of MRSA could be detected in this study.
  
  
  CONCLUSIONS
  Our study demonstrated that maternal-neonatal transmission of ESBL-E from mother to child is an important risk factor for colonization of VLBW infants. As a consequence, routine ESBL-E screening of neonates and mothers should be considered as a means of reducing neonatal morbidity and mortality.
authors.affiliation: Institute of Hygiene and Environmental Medicine, Charité University Medical Center Berlin, German National Reference Center for the Surveillance of Nosocomial Infections, Hindenburgdamm 27, D-12203 Berlin, Germany luisa.denkel@charite.de.
authors.forename: Luisa A
authors.initials: LA
authors.lastname: Denkel
authors.affiliation: Institute of Hygiene and Environmental Medicine, Charité University Medical Center Berlin, German National Reference Center for the Surveillance of Nosocomial Infections, Hindenburgdamm 27, D-12203 Berlin, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Schwab
authors.affiliation: Institute of Hygiene and Environmental Medicine, Charité University Medical Center Berlin, German National Reference Center for the Surveillance of Nosocomial Infections, Hindenburgdamm 27, D-12203 Berlin, Germany.
authors.forename: Axel
authors.initials: A
authors.lastname: Kola
authors.affiliation: Institute of Hygiene and Environmental Medicine, Charité University Medical Center Berlin, German National Reference Center for the Surveillance of Nosocomial Infections, Hindenburgdamm 27, D-12203 Berlin, Germany.
authors.forename: Rasmus
authors.initials: R
authors.lastname: Leistner
authors.affiliation: Department of Neonatology, Charité University Medical Center Berlin, Augustenburger Platz 1, D-13353 Berlin, Germany.
authors.forename: Lars
authors.initials: L
authors.lastname: Garten
authors.affiliation: Department of Obstetrics, Charité University Medical Center Berlin, Augustenburger Platz 1, D-13353 Berlin, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: von Weizsäcker
authors.affiliation: Institute of Hygiene and Environmental Medicine, Charité University Medical Center Berlin, German National Reference Center for the Surveillance of Nosocomial Infections, Hindenburgdamm 27, D-12203 Berlin, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Geffers
authors.affiliation: Institute of Hygiene and Environmental Medicine, Charité University Medical Center Berlin, German National Reference Center for the Surveillance of Nosocomial Infections, Hindenburgdamm 27, D-12203 Berlin, Germany.
authors.forename: Petra
authors.initials: P
authors.lastname: Gastmeier
authors.affiliation: Institute of Hygiene and Environmental Medicine, Charité University Medical Center Berlin, German National Reference Center for the Surveillance of Nosocomial Infections, Hindenburgdamm 27, D-12203 Berlin, Germany.
authors.forename: Brar
authors.initials: B
authors.lastname: Piening
mesh_terms: D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission; D004755:Enterobacteriaceae / Q000187:drug effects* / Q000472:pathogenicity; D004756:Enterobacteriaceae Infections / Q000188:drug therapy / Q000453:epidemiology / Q000635:transmission*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight; D018445:Infectious Disease Transmission, Vertical; D007363:Intensive Care Units, Neonatal; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000472:pathogenicity; D009035:Mothers; D012307:Risk Factors; D001618:beta-Lactamases / Q000096:biosynthesis*
chemical_list: D001618:beta-Lactamases
keywords: MRSA; neonates; screening; transmission