High rate of neonates colonized by methicillin-resistant Staphylococcus species in an Intensive Care Unit

J Infect Dev Ctries. 2019 Sep 30;13(9):810-816. doi: 10.3855/jidc.11241.

Abstract

Introduction: Staphylococcal colonization is a risk factor for healthcare-associated infections, which are frequent in Neonatal Intensive Care Units (NICU). This study analyzed microbiology, epidemiology and clinical aspects of Staphylococcus spp. colonizing neonates.

Methodology: Nasal or periumbilical swabs were evaluated from 175 newborns admitted to a NICU of a Rio de Janeiro hospital from March to September 2009. Clinical data were obtained from the medical records. SCCmec typing and the mecA and Panton-Valentine Leukocidin (PVL) genes were detected by PCR. Clonal diversity was evaluated by pulsed-field gel electrophoresis.

Results: Staphylococcus spp. isolates were detected in 98 (56%) neonates, 66.3% of them had birth weight ≤ 2500 g, 62.2% were preterm (˂ 37 weeks) and the mean length of hospitalization was 14.9 days. Among the 133 isolates identified, 48.1% were S. epidermidis, 23.3% S. haemolyticus and 13.5% S. aureus. Methicillin-resistant Staphylococcus isolate was detected in 77.6% of neonates. The methicillin-resistant S. aureus isolates carried the SCCmec type IV, while 94.6% of S. epidermidis and 85.7% of S. haemolyticus presented non-typeable cassettes. Among the S. aureus, 55.6% had PVL genes and the USA800 genotype was prevalent. Two genotypes of S. epidermidis and one of S. haemolyticus clustered 42.2% and 25.8% of the isolates, respectively. S haemolyticus colonization was associated with the use of parenteral nutrition and mechanical ventilation.

Conclusion: High rate of neonates colonized by methicillin-resistant Staphylococcus species and the permanence of clones circulating in the NICU highlight the importance for continuous and preventive surveillance in this high-risk population.

Keywords: Staphylococcus species; clinical aspects; clonal diversity; colonization; multiresistance; neonates.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Anti-Bacterial Agents / therapeutic use
  • Brazil / epidemiology
  • Cross Infection / drug therapy
  • Cross Infection / epidemiology
  • Cross Infection / microbiology
  • Electrophoresis, Gel, Pulsed-Field
  • Female
  • Humans
  • Infant, Newborn
  • Intensive Care Units, Neonatal
  • Male
  • Methicillin-Resistant Staphylococcus aureus / drug effects
  • Methicillin-Resistant Staphylococcus aureus / genetics*
  • Methicillin-Resistant Staphylococcus aureus / isolation & purification
  • Microbial Sensitivity Tests
  • Polymerase Chain Reaction
  • Staphylococcal Infections / drug therapy
  • Staphylococcal Infections / epidemiology
  • Staphylococcal Infections / microbiology*

Substances

  • Anti-Bacterial Agents