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Výskyt antimikrobiální rezistence u streptokoků (převážně beta-hemolytických) z ran pacientů
Kuropata, Daniel
Recently, a frequent occurrence of antibiotic resistance has been observed, and is still increasing. Therefore, it is important to constantly monitor this resistance, which was the aim of this work for Streptococcus genera. The literature review is focused on the selected species of streptococci (S. agalactiae, S. dysga-lactiae subsp. equisimilis, S. pyogenes, S. mitis and S. oralis), antibiotics, including their mechanism of action, and antibiotic resistance with an emphasis on its emergence, spread, mechanisms, determining genes and the risks it presents. In the experimental part, the occurrence of resistance in streptococci (especially beta-haemolytic) isolated from patients’ wounds at the Trauma Hospital in Brno was monitored. For this purpose, determination of the minimum inhibitory concentration (MIC), analysis of the resistance phenotype to macrolides, lincosamides and streptogramin B (MLS) using the D-test and resistance gene screening by polymerase chain reaction (PCR) were used. Among the 31 clinical isolates the prevalence of resistance to cotrimoxazole (96.8%), ciprofloxacin (71%), tetracycline (29%), erythromycin (25.5%), clidamycin (16 .1%), ampicillin (3.2%) and oxacillin (3.2%) was found by using MIC. Resistance to chloramphenicol, gentamicin, vancomycin, teicoplanin, linezolid, tigecycline and nitrofurantoin has not been detected. The D-test was performed with erythromycin-resistant isolates. The constitutive (cMLS) phenotype was detected in 62.5% of erythromycin-resistant isolates, inducible (iMLS) in 25% and M phenotype in 12.5%. The PCR method confirmed the presence of selected resistance genes, namely ermA (16.1%), ermB (6.5%), mefA (3.2%), tetO (3.2%), tetM (25.8%) and intTn (32.3%). This study demonstrated that all streptococcal isolates from patients’ wounds are resistant to some of the tested antibiotics. Moreover, multiresistance was detected in some isolates.
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