Increase in Penicillin Non-Susceptibility in Group B Streptococci Alongside Rising Isolation Rates-Based on 24 Years...

Area of Science:

• Microbiology
• Infectious Diseases
• Clinical Diagnostics

Background:

• Group B Streptococcus (GBS) is a significant pathogen causing neonatal sepsis, pneumonia, and meningitis, and also affects adults, particularly the elderly and those with diabetes.
• Penicillin is the primary treatment for GBS infections, with most strains historically showing susceptibility.
• Emerging trends in GBS prevalence and antimicrobial resistance necessitate updated epidemiological data.

Purpose of the Study:

• To investigate the temporal trends of GBS isolation rates at a university hospital over a 24-year period.
• To analyze the changes in penicillin non-susceptibility among GBS isolates over the same timeframe.
• To assess the antimicrobial susceptibility patterns of penicillin non-susceptible GBS strains.

Main Methods:

• Retrospective analysis of 24 years (2000-2023) of microbiological data from Ilsan Paik Hospital.
• Identification and susceptibility testing of GBS isolates using the Vitek 2 system and CLSI guidelines.
• Data aggregation and trend analysis using WHONET 2023, with statistical comparisons between three defined time intervals.

Main Results:

• A total of 3003 GBS isolates were identified from 257,884 total isolates (1.16%).
• Significant increases in both GBS isolation rates (p=0.0001) and penicillin non-susceptible (PCN-NS) GBS rates (p=0.009) were observed across the study periods.
• PCN-NS GBS isolates demonstrated reduced susceptibility to all tested antimicrobials compared to susceptible strains.

Conclusions:

• There is a statistically significant upward trend in both GBS isolation and penicillin non-susceptibility over the past 24 years.
• The emergence of multidrug-resistant GBS strains underscores the importance of continuous antimicrobial susceptibility monitoring.
• Interdisciplinary collaboration between microbiologists and clinicians is crucial for effective management and prevention of GBS infections.