New effective economic microbial test-system for screening of microbial metabolites, that are inhibitors of sterol biosynthesis, is proposed. It is based on cultivation of fungal strain Acremonium fusidioides (former Fusidium coccineum), that produces fusidic acid (fusidin) that is antibiotic of steroid structure. Great similarity of fusidic acid biosynthesis in fungous strain and cholesterol biosynthesis in human organism, coincidence of their initial steps till squalene formation, allows use A. fusidioides as a model for estimation of microbial secondary metabolites that are potential inhibitors of sterol biosynthesis. Such inhibitors in A.fusidioides model are revealed as compounds that strongly reduce fusidin production without any visible influence on fungus growth. Mevalonate that is one of the crucial intermediates of sterol biosynthesis could be successfully applied for removal of inhibition induced by some microbial metabolites. A.fusidioides test-system can be easily mechanized because of miniaturization of microbiological procedures, cultivation in 6-, 24-, or 96-well plates and usage of automatic micropipettes and dispensers. The results of this model are well correlated with the ones obtained with human cells (Hep G2 test-system, offered earlier). A.fusidioides test-system can be applied at rather early stages of screening procedures and is quite effective for testing of crude extracts of producers' culture liquid.

The study involved 25 Isolates of gramnegative carbapenemase-producing bacteria. 17 isolates of Klebsiella pneumonia produced carbapenemase NDM-1 and were highly resistant to cephalosporins (MIC>128 mcg/ml), carbapenems (MIC>16 mcg/ml), aminoglycosides and fluoroquinolones, while among them 4 isolates preserved susceptibility to azthreonam and all of them were susceptible to tigecycline and polymyxin. 2 isolates of Acinetobacter genomospecies 13 produced NDM-1 and were resistant to all the beta-lactams and amikacin, while preserved susceptibility to gentamicin, co-trimoxazole, tigecycline and polymyxin, the susceptibility to ciprofloxacin being lowered. Carbapenemase VIM-4 was produced by 2 isolates of Enterobacter cloacae, which were highly resistant to cephalosporins and azthreonam, significant synergism being observed between cefepim and clavulanate. The resistance of the isolates to carbapenems was low (MIC 0.5-4.0 mcg/ml), they also being resistant to aminoglycosides and ciprofloxacin and susceptible to tigecycline and polymyxin. Carbapenemases KPC-2 were detected in 2 isolates of K.pneumoniae and in 1 isolate of E.cloacae. The above isolates were resistant to all the beta-lactams, ciprofloxacin, aminoglycosides and co-trimoxazole. 1 isolate of E.cloacae showed resistance to tigecycline and 1 isolate of K.pneumoniae was resistant to polymyxin. Carbapenemase OXA-48 was detected in 1 isolate of K.pneumoniae. It was resistant to all the beta-lactams, ciprofloxacin and co-trimoxazole and susceptible to aminoglycosides, tigecycline and polymyxin.

Antimicrobial properties of a composite based on decamethoxine and modified polysaccharides (carboxymethylamylum, oxyethylcellulose) were studied. The composite was shown to have high antimicrobial activity against grampositive and gramnegative bacteria under different conditions of the experiment.

Antibacterial spectra of Tobramycin-Gobby(solution for inhalation 60 mg/ml, «GobbyNovag C.A.», Argentina) and Toby (solution for inhalation 60 mg/ml, «Cardinal Health Inc.», USA) were estimated comparatively. The estimation involved 75 clinical isolates of microorganisms from the Culture Collection of the National Research Centre of Antibiotics and standard strains of Staphylococcus aureus АТСС 29213, Escherichia coli АТСС 25922, Pseudomonas aeruginosa АТСС 27853.It was shown that Tobramycin-Gobby (solution for inhalation 60 mg/ml, «GobbyNovag C.A.», Argentina) and Toby (solution for inhalation 60 mg/ml, «Cardinal Health Inc.», USA) were identical by their antibacterial spectra.

Isolation of lysozyme from hemolymph of Alveonasus lahorensis (Acari: Parasitiformes, Argasidae) and Hyalomma marginatum (Acari: Parasitiformes, Ixodidae) with using ultrasound is described. It was shown that the bactericidal effect of the ultrasound-extracted lysozyme against Staphylococcus aureus and Micrococcus luteus significantly exceeded that of the chicken egg lysozyme and lysozyme from ticks without ultrasound exposure. Disintegration of the hemolymph cells increased lysozyme production.

The problem of hospital-acquired infections due to coagulase-negative staphylococci (CoNS) in neonatal intensive care units is crucial over the last 20 years in the world. Neonates with very low or extremely low body weight belong to a special group of risks by the CoNS infection. However, in Russia CoNS up to now are frequently considered as contaminants and not as the main etiologic factors of pneumonia and sepsis in extremely premature infants. It was shown that hospital strains of CoNS causing fatal infections in extremely premature infants are always present in intensive care units.

The use of reamberin for prophylaxis of side effects was estimated In 257 patients with tuberculosis of the respiratory organs under the chemotherapy. The reference group involved 241 patients treated with the chemotherapeutics alone. Reamberin in the treatment of the patients, including subjects with multidrug resistant Mycobacterium tuberculosis, promoted a 2-fold decrease in the frequency of the intoxication syndrome during the first month of the treatment. Adverse reactions (toxic, allergic) to the antituberculosis chemotherapeutics were 2.4 times less frequent in the patients additionally treated with reamberin. Positive effect of reamberin on the activity of AlAT and AsAT was observed, the effect being higher, when the pathogen was susceptible to the drugs.

In vitro activity of dioxidin against pathogens of nosocomial infections and its cytotoxicity were estimated. The study involved 300 isolates from patients with nosocomial infections. The MICs of dioxidin were determined with the method of serial dilutions in broth. The dioxidin cytotoxicity was investigated with the MTT assay to assign the cell culture viability. In concentrations of 2 to 1024 mcg/ml dioxidin was active against 279/300 (93%) strains. The drug inhibited the growth of all the gramnegative isolates. The highest activity was observed against Enterobacteriaceae vs. nonfermenting gramnegative bacteria: the median, minimum and maximum MICs of dioxidin were 12 (4-32) and 32 (16-64) mcg/ml respectively. The dioxidin activity against gramnegative bacteria and fungi was lower. The MIC of dioxidin for 7/70 (10%) staphylococcal isolates, 9/28 (32%) enterococcal isolates and all the Candida isolates was > 1024 mcg/ml. The IC₅₀ of dioxidin was 2.4+0.3 mM (low cytotoxicity). The results showed that the use of dioxidin as an antimicrobial for local application was advisable in the treatment of gramnegative bacterial infections provided adequate tissue concentrations were attained.

Cytochemical indices of peripheral blood leukocytes were investigated. The results allowed to estimate the level of the disease severity and to control the immunotropic therapy efficacy. Dysbalance of the interleukocytic microbicidical systems (IMS) of neutrophils reflected the nonspecific resisistance and the state of the phagocytic system as an objective criterion of the adaptation syndrome. Association of the deficiency of the IMS components and blood serum fibronectin were considered as a predisposition of bacterial complications. Cycloferon activated the phagocyte metabolic activity and promoted elimination of the main clinical symptoms of the disease (acute infective damage of the meninges, temperature elevation, intoxication signs), thus making shorter the hospitalization terms.