Antibiotics Susceptability of Streptococcus pneumoniae Isolated from Single Tertiary Childrens' Hospital Since 2014 and Choice of Appropriate Empirical Antibiotics

ABSTRACT

PURPOSE: We investigated the distribution and antimicrobial resistance of pneumococcal isolates from hospitalized children at Asan Medical Center for recent 4 years, and aimed to recommend proper choice of empirical antibiotics for pneumococcal infection. METHODS: From March 2014 to May 2018, children admitted to Asan Medical Center Childrens' Hospital with pneumococcal infection were subjected for evaluation of minimal inhibitory concentration (MIC) for β-lactams and macrolide antibiotics. Patient's age, underlying disease, gender were retrospectively collected. Using Monte Carlo simulation model and MIC from our study, we predicted the rate of treatment success with amoxicillin treatment. RESULTS: Sixty-three isolates were analyzed including 20.6% (n=13) of invasive isolates, and 79.4% (n=50) of non-invasive isolates; median age were 3.3 years old, and 87.3% of the pneumococcal infections occurred to children with underlying disease. Overall susceptibility rate was 49.2%, 68.2%, and 74.6% for amoxicillin, parenteral penicillin, and cefotaxime respectively. 23.8% and 9.5% of the isolates showed high resistance for amoxicillin, and cefotaxime. Only 4.8% (n=3) were susceptible to erythromycin. Monte Carlo simulation model revealed the likelihood of treatment success was 46.0% at the dosage of 90 mg/kg/day of amoxicillin. CONCLUSIONS: Recent pneumococcal isolates from pediatric patients with underlying disease revealed high resistance for amoxicillin and cefotaxime, and high resistance for erythromycin. Prudent choice of antibiotics based on the local data of resistance cannot be emphasized enough, especially in high risk patients with underlying disease, and timely vaccination should be implemented for prevention of the spread of resistant strains.