title: Molecular epidemiology of coagulase-negative Staphylococcus carriage in neonates admitted to an intensive care unit in Brazil.
abstract: BACKGROUND
  Nasal colonization with coagulase-negative Staphylococcus (CoNS) has been described as a risk factor for subsequent systemic infection. In this study, we evaluated the genetic profile of CoNS isolates colonizing the nares of children admitted to a neonatal intensive care unit (NICU).
  
  
  METHODS
  We assessed CoNS carriage at admittance and discharge among newborns admitted to a NICU from July 2007 through May 2008 in one of the major municipalities of Brazil. Isolates were screened on mannitol salt agar and tryptic soy broth and tested for susceptibility to antimicrobials using the disc diffusion method. Polymerase chain reaction (PCR) was used to determine the species, the presence of the mecA gene, and to perform SCCmec typing. S. epidermidis and S. haemolyticus isolated from the same child at both admission and discharge were characterized by PFGE.
  
  
  RESULTS
  Among 429 neonates admitted to the NICU, 392 (91.4%) had nasal swabs collected at both admission and discharge. The incidence of CoNS during the hospitalization period was 55.9% (95% confidence interval [CI]: 50.9-60.7). The most frequently isolated species were S. haemolyticus (38.3%) and S.epidermidis (38.0%). Multidrug resistance (MDR) was detected in 2.2% and 29.9% of the CoNS isolates, respectively at admittance and discharge (p = 0.053). The mecA gene was more prevalent among strains isolated at discharge (83.6%) than those isolated at admission (60%); overall, SCCmec type I was isolated most frequently. The length of hospitalization was associated with colonization by MDR isolates (p < 0.005). Great genetic diversity was observed among S. epidermidis and S. haemolyticus.
  
  
  CONCLUSIONS
  NICU represents an environment of risk for colonization by MDR CoNS. Neonates admitted to the NICU can become a reservoir of CoNS strains with the potential to spread MDR strains into the community.
authors.affiliation: Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia, GO, Brazil. andre.kipnis@gmail.com.
authors.forename: Yves Mauro
authors.initials: YM
authors.lastname: Ternes
authors.forename: Juliana
authors.initials: J
authors.lastname: Lamaro-Cardoso
authors.forename: Maria Cláudia Porfirio
authors.initials: MC
authors.lastname: André
authors.forename: Vicente Porfírio
authors.initials: VP
authors.lastname: Pessoa
authors.forename: Maria Aparecida da Silva
authors.initials: MA
authors.lastname: Vieira
authors.forename: Ruth
authors.initials: R
authors.lastname: Minamisava
authors.forename: Ana Lúcia
authors.initials: AL
authors.lastname: Andrade
authors.forename: André
authors.initials: A
authors.lastname: Kipnis
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D015373:Bacterial Typing Techniques; D001938:Brazil / Q000453:epidemiology; D003030:Coagulase / Q000235:genetics / Q000378:metabolism; D024881:Drug Resistance, Bacterial; D005260:Female; D006760:Hospitalization; D006801:Humans; D007231:Infant, Newborn; D007362:Intensive Care Units / Q000706:statistics & numerical data; D008297:Male; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D013210:Staphylococcus / Q000145:classification / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D003030:Coagulase