Prevalence and molecular characterization of Staphylococcus aureus from human stool samples

Area of Science:

• Medical Microbiology
• Infectious Diseases
• Clinical Epidemiology

Background:

• Investigating intestinal Staphylococcus aureus (S. aureus) colonization prevalence in a major teaching hospital.
• Understanding the molecular features of S. aureus strains found in patient intestinal tracts.
• Identifying key risk factors associated with S. aureus intestinal colonization.

Purpose of the Study:

• To determine the prevalence and molecular characteristics of intestinal S. aureus colonization.
• To identify risk factors associated with S. aureus intestinal colonization in patients.

Main Methods:

• Cross-sectional study of 781 patient specimens.
• S. aureus identification via culture, with methicillin-resistance confirmed by mecA gene PCR.
• PVL PCR, spa typing, antimicrobial sensitivity testing, and a nested case-control study for risk factor analysis.

Main Results:

• S. aureus intestinal colonization found in 9.3% of 625 patients.
• High rates of antibiotic resistance observed (e.g., oxacillin 43.1%, erythromycin 51.7%).
• Gastrointestinal disease significantly increased odds of colonization (aOR: 13.9).

Conclusions:

• S. aureus intestinal colonization is present in hospital patients.
• Antibiotic-resistant strains may act as reservoirs for infections and transmission.
• Gastrointestinal conditions are a primary risk factor for colonization.