Antimicrobial resistance of staphylococci in pediatric hospitals

Abstract

Objective. To determine frequency of Staphylococcus isolation and antimicrobial resistance in hospitalized children with different types of infections. Materials and Methods. Species identification and antimicrobial susceptibility testing in staphylococci were performed on a WalkAway 96 analyzer using Pos Combo type 20 tablets, and mecA gene detection was performed on a RotorGene 6000 amplifier with a set of AmpliSens MRSA-screen FL. Results. A total of 876 strains of staphylococci isolated in children’s hospitals were tested. The species and antibiotic resistance of Staphylococcus aureus and coagulase-negative staphylococci were studied. The most common types of staphylococci were: S. aureus – 36.0%, S. epidermidis – 23.0%, S. haemolyticus – 19.7%, S. hominis – 14.0%. As many as 35.3% of isolates were methicillin-resistant, while 32.9% of methicillin-resistant S. aureus was detected, and 65.6% of methicillin-resistant strains were among the most frequently isolated coagulase-negative staphylococci. The mecA gene was detected in 97.1% of phenotypically methicillin-resistant strains. Antibiotic resistance of S. aureus and coagulase-negative staphylococci circulating in children’s hospitals is very high. Two strains of S. aureus with intermediate resistance to vancomycin (MIC = 4 mcg/ml) and one S. aureus with resistance to linezolid (MIC = 8 mcg/ ml) were isolated. Among coagulase-negative staphylococci, two strains with intermediate resistance to vancomycin (MIC = 8 mcg/ml), two resistant to vancomycin (MIC = 16 mcg/ml), and 6 strains resistant to linezolid (MIC from 8 to 32 mcg/ml) were identified. Conclusions. Antimicrobial resistance of staphylococci in children’s hospitals does not depend on the species, more than half of the isolated isolates are methicillin-resistant. During the reporting period, staphylococci resistant to vancomycin and linezolid were identified, which requires resistance mechanisms to be determined.