Related Experiment Videos
Molecular characterization of epidemic multiresistant Staphylococcus haemolyticus isolates
1Department of Clinical Pathology, Juntendo University School of Medicine, Tokyo, Japan.
Diagnostic Microbiology and Infectious Disease
|January 13, 1999
Summary
Multidrug-resistant Staphylococcus haemolyticus strains were found in a neonatal intensive care unit. Hospital staff acted as a reservoir, facilitating the spread of these resistant bacteria within the hospital setting.
Area of Science:
- Microbiology
- Infectious Diseases
- Hospital Epidemiology
Background:
- Staphylococcus haemolyticus is an opportunistic pathogen.
- Multidrug-resistant (MDR) strains pose a significant threat in healthcare settings, particularly in neonatal intensive care units (NICUs).
- Understanding the transmission dynamics of MDR S. haemolyticus is crucial for infection control.
Purpose of the Study:
- To investigate the prevalence and characteristics of multidrug-resistant Staphylococcus haemolyticus.
- To determine the role of hospital staff in the transmission of MDR S. haemolyticus.
- To identify the transmission patterns of MDR S. haemolyticus within a hospital environment.
Main Methods:
- Antimicrobial susceptibility testing was performed on 55 S. haemolyticus isolates from patients and NICU staff against 12 antimicrobial agents.
- Pulsed-field gel electrophoresis (PFGE) was employed for molecular typing of the isolates after SmaI and SstII digestion.
- Epidemiological data was analyzed to correlate isolate patterns with patient and staff data.
Main Results:
- Thirty-four of the 55 S. haemolyticus isolates exhibited multidrug resistance, showing resistance to oxacillin, ampicillin, cefazolin, cefmetazole, imipenem, and gentamicin.
- These MDR isolates demonstrated higher resistance frequencies to tobramycin and ofloxacin, with elevated Minimum Inhibitory Concentrations (MICs) for vancomycin (2-4 µg/mL), though no vancomycin resistance was observed.
- PFGE analysis revealed an endemic pulsed-field gel electrophoresis pattern among the MDR isolates, suggesting clonal spread.
- The study identified hospital staff as a potential reservoir for MDR S. haemolyticus.
Conclusions:
- The findings indicate that multidrug-resistant Staphylococcus haemolyticus infections and colonization in the NICU are hospital-acquired.
- Hospital staff play a significant role in the local transmission and persistence of MDR S. haemolyticus.
- Effective infection control strategies targeting healthcare workers are essential to curb the spread of MDR S. haemolyticus in hospital settings.