Long persistence of methicillin-susceptible strains of Staphylococcus aureus causing sepsis in a neonatal intensive...

Area of Science:

• Medical Microbiology
• Infectious Diseases
• Neonatal Health

Background:

• Neonatal bacteremia poses a significant threat to infant health.
• Staphylococcus aureus is a common cause of hospital-acquired infections, including in neonates.
• Understanding the molecular epidemiology of S. aureus is crucial for infection control.

Purpose of the Study:

• To investigate the molecular epidemiology of Staphylococcus aureus strains causing bacteremia in neonates.
• To identify dominant clones and their characteristics during the study period.
• To assess the potential role of healthcare workers (HCWs) in the transmission of these strains.

Main Methods:

• Molecular typing techniques were used to analyze Staphylococcus aureus isolates from neonatal bacteremia cases.
• Epidemiological data were collected from 2002 to 2005.
• Colonization of healthcare workers (HCWs) was investigated for specific bacteremic clones.

Main Results:

• Seven distinct Staphylococcus aureus clones were identified among neonatal bacteremia cases.
• Four Methicillin-Susceptible Staphylococcus aureus (MSSA) clones accounted for 80% of the infections.
• Persistence and reappearance of certain clones were observed throughout the study period.
• Three bacteremic clones, notably clone C, were found colonizing HCWs, with clone C harbored by at least 15% of HCWs.

Conclusions:

• Molecular epidemiology reveals dominant MSSA clones responsible for the majority of neonatal bacteremia.
• The persistence and reappearance of specific clones highlight challenges in controlling S. aureus neonatal infections.
• Healthcare worker colonization with key bacteremic clones suggests a potential transmission reservoir and emphasizes the need for stringent infection control measures.