Clinical Microbiology and Antimicrobial Chemotherapy. 2020; 22(4):272-275
To determine frequency of Staphylococcus isolation and antimicrobial resistance in hospitalized children with different types of infections.
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.
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.
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.