The Prevalence of Genetic Determinants of Antibiotic Resistance, which are of Particular Epidemiological Consequences, in the Microbiota of the Oropharyngeal Swabs in Patients with Cystic Fibrosis

Relevance. Antibiotic resistance of microorganisms can contribute to the chronicity of the inflammatory process, lead to an increase in the cost of treating patients and make it difficult to eradicate the pathogen. Patients with cystic fibrosis constantly require medical supervision, regular visits to medical institutions, and therefore there is a high risk of infection with nosocomial antibiotic- resistant strains. In addition, the necessary intake of antibacterial drugs provides an advantage for the reproduction of resistant microorganisms.

Aim. Comparison of the frequency of detection of antibiotic resistance determinants in oropharyngeal swabs in children with cystic fibrosis and conditionally healthy children using molecular biological methods.

Materials and methods. A PCR study of oropharyngeal discharge from 100 children with cystic fibrosis and 100 children from the control (healthy comparison subject) group was performed. Genetic antibiotic resistance locus: metallo-b-lactamases of the VIM, IMP and NDM groups; carbapenemase genes of the KPC and OXA-48 groups; extended-spectrum beta-lactamase genes of the CTX-M group and the mecA gene were detected by polymerase chain reaction (PCR) with hybridization-fluorescence detection.

Results and discussion. As a result of the analysis, a statistically significant increase in the frequency of detection of genetic determinants of antibiotic resistance in the microbiota of the oropharyngeal discharge in children with cystic fibrosis was found compared with healthy children (p<0.001). The chances of detecting antibiotic resistance loci in the discharge of the oropharynx among children with cystic fibrosis are 38.5 times higher than among healthy children (95% CI: 5.1-289.5). In 28% of children with cystic fibrosis, DNA of the genetic determinants of antibiotic resistance was detected in the microbiome of the discharge of the oropharynx. A high percentage of the presence of genetic determinants of antibiotic resistance may be the reason for the ineffectiveness of antibiotic therapy.

Conclusion. Due to the high occurrence in the microbiome of the oropharyngeal discharge of patients with cystic fibrosis of genetic antibiotic resistance locus that are of particular clinical and/or epidemiological significance, and the high risk of the spread of antibiotic-resistant strains outside medical institutions, it is necessary to include this group of patients in regular epidemiological monitoring.

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