title: Enterobacteriaceae infections of very low birth weight infants in Polish neonatal intensive care units: resistance and cross-transmission.
abstract: BACKGROUND
  The aims of our study were analysis of the occurrence of infections by members of the Enterobacteriaceae family in 6 Polish neonatal intensive care units in 2009, their drug resistance, the epidemiology of extended-spectrum β-lactamase (ESBL)-producing strains and the possibility of using modern tools of microbiology diagnosis in infection control, especially for the reduction of antimicrobial resistance.
  
  
  METHODS
  A prospective surveillance covered 910 newborns. Case patients were defined as neonates with very low birth weight who had clinical signs of septicemia, pneumonia or necrotizing enterocolitis. Early-onset infection was defined as infection diagnosed within 3 days after delivery.
  
  
  RESULTS
  The incidence of Enterobacteriaceae infections was 2.6/1000 patient-days. The risk of Enterobacteriaceae pneumonia increased with the length of hospitalization (P = 0.0356). The most common pathogen was Escherichia coli (12.4% of all strains, in early-onset infection 18.5%) and Klebsiella spp. (9.1% of all). The ESBL phenotype was found in 37% of isolates, of which 89.3% were producing CTX-M-type, 70.2% TEM-type and 8.5% SHV-type. Epidemic clones were detected in the 2 studied neonatal intensive care units: 6 of the 9 ESBL-positive Enterobacter cloacae and 16 of the 18 ESBL-positive Klebsiella pneumoniae strains were classified into 1 epidemic clone, which showed resistance to penicillin without inhibitors, amoxycillin/clavulanic acid, cephalosporins, aztreoname, aminoglycosides and trimethoprim/sulfamethoxazole.
  
  
  CONCLUSIONS
  Enterobacteriaceae bacilli are a significant problem in neonatal intensive care units, especially in early-onset infection and for long hospitalized very low birth weight infants. The observed high drug resistance was in large part related to the dominance of epidemic strains as a result of horizontal transmission. The best way to reduce drug resistance would be adequate procedures of isolation and hand hygiene.
authors: Microbiology, Jagiellonian University Medical College, Krakow, Poland. mbmach@cyf-kr.edu.pl
authors: Jadwiga
authors: J
authors: Wójkowska-Mach
authors: Agnieszka
authors: A
authors: Chmielarczyk
authors: Maria
authors: M
authors: Borszewska-Kornacka
authors: Joanna
authors: J
authors: Domańska
authors: Janusz
authors: J
authors: Gadzinowski
authors: Ewa
authors: E
authors: Gulczyńska
authors: Marek
authors: M
authors: Nowiczewski
authors: Ewa
authors: E
authors: Helwich
authors: Agnieszka
authors: A
authors: Kordek
authors: Dorota
authors: D
authors: Pawlik
authors: Joanna
authors: J
authors: Jursa-Kulesza
authors: Stefania
authors: S
authors: Giedrys-Kalemba
authors: Jerzy
authors: J
authors: Szczapa
authors: Piotr B
authors: PB
authors: Heczko
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D003428:Cross Infection / Q000453:epidemiology* / Q000635:transmission*; D018562:Disease Transmission, Infectious; D024901:Drug Resistance, Multiple, Bacterial; D004755:Enterobacteriaceae / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D004756:Enterobacteriaceae Infections / Q000453:epidemiology* / Q000635:transmission*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight; D007363:Intensive Care Units, Neonatal; D008297:Male; D017720:Molecular Epidemiology; D058889:Molecular Typing; D011044:Poland / Q000453:epidemiology; D011446:Prospective Studies; D001618:beta-Lactamases / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001618:beta-Lactamases