THE EFFICACY OF SILVER NANOPARTICLES ON THE MODEL OF CLINICAL ISOLATES OF MYCOBACTERIUM TUBERCULOSIS WITH A VARIETY OF DRUG RESISTANT
The paper presents the results of in vitro suppressive activity of silver nanoparticles on clinical MBT isolates with different drug resistant pathogen. In the group 1 were studied in 117 the office of isolates with resistance to isoniazid and other drugs, but sensitivity to rifampicin, in the 2nd - 108 isolates of MDR bacteria. In the 1st group the most frequent spectra HSE (17,9%), HSKE (12,8%), HS (10.3 per cent), in the 2nd - HRSE (8,3%), HRSK and HRSKE (7.4% each). The most frequently drug resistance of isolates of group 1 was observed to streptomycin (80,3%), ethambutol (59.8%), and kanamycin/amikacin (39,3%), protionamide (21,4%), fluoroquinolones (20,5%). Among the isolates of group 2 maximum resistance was observed to streptomycin (94.4 per cent), kanamycin/amikacin (56,5%), ethambutol (52,8%), fluoroquinolones (37,0%), protionamide (34.3 percent). There were 1350 bacteriological studies. Drug resistance of the pathogen was determined by the method of absolute concentrations in dense environments and by the method of proportions on the automatic analyzer "Bactec MGIT 960" and also included PCR-based diagnostic analyzer GeneXpert. Studied suppressive activity of silver nanoparticles in isolated form in concentration of 5, 25, 50 pg/ml was also investigated in vitro antitubercular activity of nanocomposite consisting of silver nanoparticles in concentrations 5, 25, 50 pg/ml and anti-TB drug isoniazid at a concentration of 1 pg/ml. Nanoparticles with a size of 3-60 nm was obtained by electrochemical dissolution of the metal. Studies have shown that nanoparticles in a solution maintained stability during storage for 300 days. When mixing solutions of silver nanoparticles and isoniazid, as studies have shown that silver nanoparticles had no effect on the chemical stability and concentration of isoniazid in the solution exposure for 24 hours. Complete and significant growth suppression by the ILO (bactericidal effect) of nanoparticles on isolates of the group 1 was observed in 48.1 ± 0,53% cases, with the greatest suppressive activity was observed when the nanoparticles concentration 5 pg/ml to 58.1 ± 0,93%. The combination of nanoparticles with isoniazid increase the bactericidal action was 17.2% (p < 0.05). Bactericidal activity of isolated nanoparticles on clinical isolates of group 2 MDR was 41.7%. The combined use of nanoparticles with isoniazid provided the increase of bactericidal action of 18.8% (p < 0.05). Obtained in the experiment in vitro results indicate a potentiating effect of silver nanoparticles on isoniazid.