[ANTIBIOTICS SENSITIVITY OF STAPHYLOCOCCUS AUREUS, PSEUDOMONAS AERUGINOSA AND BACTERIA OF BURKHOLDERIA CEPACIA COMPLEX, PERSISTING IN LUNGS OF PATIENTS WITH MUCOVISCIDOSIS (MV)].

AIM: Study the spectrum of resistance to antibiotics and its variability of Staphylococcus aureus, Pseudomonas aeruginosa and Burkholderia cepacia complex (BCC), persisting in lungs of MV patients. MATERIALS AND METHODS: 312 strains of S. aureus, 213 strains of P. aeruginosa, 186 strains of BCC were studied. Monitoring of antibiotics sensitivity was carried out in strains, isolated from 30 patients with chronic S. aureus infection, from 22 patients with chronic BCC infection and from 21 patients with chronic pseudomonas infection. Interval of monitoring was from 14 days to 5 years 7 months. RESULTS: Study of S. aureus, P. aeruginosa and BCC strains has shown, that 35 and 33.3% of cases of staphylococcus infection, 37 and 46% of pseudomonas infection in children and adults, respectively, 100% of BCC infections were determined by multi-resistant clones. Study of genotypically identical strains, isolated from a single patient at different stages, has shown a change in antibiotics sensitivity as a result of persistence. CONCLUSION: Persisent infection of lungs in patients with MV is determined: by exchanging clones with varying antibiotics sensitivity or prolonged circulation of a single clone with a high degree of phenotypical and genotypical variability, that determine alteration of seeding of sensitive and resistant strains from the same patient during monitoring. This confirms the necessity of study of antibiotics sensitivity of strains for prescription of antibacterial therapy.

[Characterization of genotypes for Burkholderia cepacia complex strains isolated from patients in hospitals of Russian Federation].

88 cultures of microorganisms referred to the Burkholderia cepacia complex (Bcc) during initial identification were analyzed by multilocus sequencing (Multilocus Sequence Typing, MLST). 13 genotypes (sequence type, ST) were detected, 9 of them (708, 709, 710, 711, 712, 714, 727, 728, 729) were identified for the first time. Two new alleles for the gene trpB (357, 358), one of the genes atpD (306) and gltB (352) were detected and registered. It was found that strains of 2 genotypes (711, 712) belong to the species B. multivorans, 1 (ST102) - B. contaminans, 1 (ST51) - B. stabilis, 1 (ST729) - B. vietnamiensis. Most strains of the sample, representing 8 genotypes (208, 241, 728, 727, 708, 709, 710, 714), belong to the species B. cenocepacia. Identified genotypes differ in the global spread of the world: 4 genotype (51, 102, 208, 241) have intercontinental distribution, 1 (712) - intra. It is shown that strains causing nosocomial infections, in most cases refer to genotypes 728 and 708. Epidemiologically significant in respect of patients with cystic fibrosis should recognize genotype 709, detected in strains isolated from patients in seven federal districts (FD) of Russia. The Bcc strains of genotypes 241 (B. cenocepacia) and 729 (B. vietnamiensis) were isolated from the patients of the Far Eastern FD. They are not typical for other FD Russia. The possibility of concomitant infection in cystic fibrosis patient with two genotypes 709 - epidemiologically significant and 708 - nosocomial, was indicated. The long-termpersistence of a single genotype strain in the organism of patients with cystic fibrosis was demonstrated as for Bcc species B. cenocepacia (ST 709), so for B. multivorans (ST712). The possibility of transferring the strain Bcc, typical for nosocomial environment to patient with cystic fibrosis at surgery was observed.

Antibacterial Effect of Thiosulfinates on Multiresistant Strains of Bacteria Isolated from Patients with Cystic Fibrosis.

The multiresistance of A. ruhlandii 155B, B. cenocepacia 122, and P. aeruginosa 48B strains isolated from patients with cystic fibrosis was established. The antibacterial effect of allicin, dimethyl thiosulfinate, and dipropyl thiosulfinate on multidrug-resistant strains was shown. Thiosulfinates can have both bacteriostatic and bactericidal effects depending on the microorganism and the concentration. The studied thiosulfinates may be candidates for the development of alternative antibiotic drugs to treat infections caused by multidrug-resistant pathogens.

Problems and perspectives of molecular epidemiology of infectious diseases.

Current tendencies and problems of molecular biology and its application in infectious diseases are discussed. Basic stages of the development of molecular epidemiology as a leading tool for epidemiological studies are reviewed. More than 30 years ago, molecular epidemiology was first used to study nosocomial infections. Special attention is given to the achievements of Russian scientists, especially in the discovery of Astrakhan spotted fever Rickettsia, noncultured forms of Vibrio cholerae, and the microorganism "Montezuma." Also, the development of PCR-based methods of identification and typing of Mycobacterium tuberculosis by Russian specialists and its significant role in strategies for diagnosing and treatment of tuberculosis are discussed. Now, the most important field of application of molecular biology methods is bacterial evolution, especially with regard to pathogenic microorganisms and emerging infections. Searching for the novel pathogenic agents, establishment of the infectious nature of diseases with unclear origin, and determining the precise mechanisms of pathogenicity are most intriguing issues. So, molecular biology should play a major role both in clinical and research fields.

Human angiogenin lacks specific antimicrobial activity.

The antimicrobial activities of commercially available human angiogenin were studied against two pathogens, namely, Candida albicans and Streptococcus pneumoniae. In contrast to the data published earlier, antimicrobial action of angiogenin was rather limited and comparable to that of bovine serum albumin.