[Resistance to erythromycin in Streptococcus pneumoniae]

Area of Science:

• Microbiology
• Infectious Diseases
• Antimicrobial Resistance

Background:

• Streptococcus pneumoniae (S. pneumoniae) is a leading cause of bacterial infections worldwide.
• Antimicrobial resistance in S. pneumoniae poses a significant public health threat.
• Understanding resistance patterns is crucial for effective treatment strategies.

Purpose of the Study:

• To investigate the prevalence and patterns of erythromycin resistance in S. pneumoniae clinical isolates.
• To identify specific serotypes and patient demographics associated with resistance.
• To assess the co-resistance patterns with other antimicrobial agents.

Main Methods:

• Analysis of 640 S. pneumoniae isolates from various clinical samples over a 10-year period.
• Determination of minimum inhibitory concentrations (MICs) for erythromycin.
• Identification of serotypes and assessment of resistance to other antibiotics.

Main Results:

• Overall erythromycin resistance was 9.1%, with higher rates in serotypes 6, 14, and 19.
• Resistance was more common in isolates from ear fluid and bronchial secretions (16%) compared to blood cultures (4.5%).
• Pediatric patients showed higher resistance rates; no gradual increase over time was observed, but the last year had the highest rate.
• 94.8% of strains exhibited multidrug resistance, and 60.3% were resistant to penicillin.

Conclusions:

• Erythromycin resistance in S. pneumoniae is significant, particularly in certain serotypes and pediatric populations.
• The high prevalence of multidrug resistance suggests complex epidemiological drivers.
• Resistance patterns may not be solely linked to erythromycin usage, highlighting the need for comprehensive antimicrobial stewardship.