Experimental and clinical studies of drug regulation of the anti-lysozyme activity of microorganisms causing opportunistic infections

Experimental materials on choosing antibiotics for etiotropic therapy of opportunistic infections with an account of the regulating effect of the drugs on the ++anti-lysozyme activity of pathogens (the factor of intracellular parasitism) are presented. The in vitro data were applied to the clinical trials in 30 patients with chronic and acute pyelonephritis of the Proteus etiology and to 25 patients with chronic inflammatory diseases of Staphylococcus etiology. It was shown that the use of the antibiotics which lowered the ++anti-lysozyme activity of microorganisms promoted a more rapid disappearance of the disease clinical signs, increased 2- to 3-fold the terms of the remission and resulted in an increase in the number of the persons with complete remission (54.5 to 63.6 per cent) as compared to the use of the drugs which stimulated the pathogen property or were indifferent to it.     

Circadian rhythms of antibacterial resistance, coagulase and antilysozyme activity of Staphylococcus aureus

AIM: To determine daily dynamics of antibacterial resistance as well as antilysozyme and coagulase activity of S. aureus strains. MATERIALS AND METHODS: On an example of clinical strains of S.aureus isolated from patients with surgical infections daily dynamics of biological characteristics of staphylococci was studied. After 12 hours of incubation strains were tested for coagulase activity by standard method (test tube method), antilysozyme activity by photometric method, and antibacterial resistance by method of serial dilutions in agar. Tests were repeated each 3-hours during a day. RESULTS: Variation of levels of studied biological characteristics of staphylococci during a day was revealed. Structures of coagulase and antilysozyme circadian rhythms had some differences in different S. aureus strains. Alongside with it, similarity in temporal expression of such biological characteristics of staphylococci as antibacterial resistance and antilysozyme activity was noted. CONCLUSION: Obtained data open prospect to use biorhythmological approach in study of biological characteristics of microorganisms during evaluation of their mechanisms of adaptation to changing environmental conditions. Chronobiological approach allows to reveal periods of maximal expression of S. aureus characteristics that could be used for increasing of effectiveness of antibacterial treatment by the choice of optimal time for administration of antibiotic.     

The microbiological characteristics of soft-tissue surgical infection

The dynamic study of microflora in the foci of surgical infection of soft tissues was made. In 45 patients the course of the infectious process was characterized by the change of causative agents in the course of the disease. As established in this study the frequency of changes in the species composition of microflora in the foci of surgical infection in the course of the disease directly correlated with the occurrence of purulent septic complications requiring repeated surgical intervention. Changes in the species composition of causative agents should be regarded as their adaptation to the anti-infectious protection of the body, which is one of the regulatory mechanisms of the parasitic system.     

The characteristics of the vaginal microflora in intrauterine contraception

The results of the study of vaginal microbiocenosis in women using intrauterine contraceptives are presented. Inflammatory complications in intrauterine contraception were shown to be linked with vaginal dysbiosis. Disturbances in vaginal microbiocenosis were characterized by the deficiency of lactoflora and the presence of enterobacteria, Staphylococcus aureus, Gardnerella of fungi of the genus Candida. The problem of the possibility of complications of microbial etiology in women using intrauterine contraceptives are discussed.     

Modifying action of oxytocin on the biological properties of the causative agents of anaerobic non-clostridial infection

In a number of in vitro experiments the effect of oxytocin on the antilysozyme and anticomplemental activity of Propiobacterium propionicum, Bacteroides fragilis, Prevotella melaninogenica and Peptostreprtococcus anaerobius, isolated from patients with acute pyoinflammatory pleuropulmonary diseases, was studied. Antibiotic resistance dynamics of the infective agents under study to lincomycin, clindamycin, thienam, vancomycin was also detected. The inhibiting activity of oxytocin on the persistence properties of B. fragilis, P. melanogenica and P. anaerobius was noted. Under the influence of the preparations used changes in the sensitivity of the strains to a number of antibiotics of the lincosamide, carbapenem and glycopeptide groups were found to occur. The data thus obtained were indicative of the possible mechanisms of action of oxytocin in the treatment of acute pyoinflammatory pleuropulmonary diseases of anaerobic nonclostridial etiology.     

New method for the determination of anti-lactoferrin activity of microorganisms

A new method for the determination of the antilactoferrin activity (ALfA) of microorganisms, based on the detection of lactoferrin by the enzyme immunoassay, is proposed. The new method widens the spectrum of microorganisms to be tested, makes it possible to detect lactoferrin inactivation by bacteria producing antagonistically active substances (muramidases, organic acids, hydrogen peroxide, etc.), increases the reliability of the determination of the ALfA antilactoferrin activity of microorganisms due to the increased accuracy of its quantitative characterization. Testing of the culture fluid for lactoferrin following the growth of microorganisms in a medium with this protein revealed the capacity to inactivate lactoferrin in bacteria (Escherichia coli, Salmonella sp.) and yeast-like fungi (Candida sp.), isolated from feces and clinical material, of persons with carrier states, dysbiotic disturbances and pyoinflammatory diseases.     

Mechanisms of enterococcal survival in the host

Information on virulence and persistence factors of enterococci as important nosocomial pathogens with ever increasing multiple drug resistance is updated. The importance of the virulent and persistent properties of enterococci in the processes of adhesion to host tissues, invasion, modulation of inflammatory responses, as well as their toxic action on the host body is considered. The pathogenicity factors of enterococci are relevant to the mechanisms of the bacterial survival in the host.     

Characterization of antilysozyme and anticomplement signs in brucellae during experimental infection

The dependence of the course of experimental infection on the initial level of antilysozyme activity of Brucella clones was studied using 40 noninbred guinea pigs. As revealed in this study, the antilysozyme sign of brucellae influenced the pathogenesis of brucellosis, facilitating the prolonged survival of brucellae in the host body. The results thus obtained may be used for the prognostication of the course of Brucella infection.     

Modifying action of Saccharomyces boulardii on the biological properties of enterobacteria

The influence of the exometabolites of the fungus S. boulardii, contained in the probiotic preparation "Enterol", on the biological properties of opportunistic and pathogenic enterobacteria of fecal microflora (inactivation of lysozyme, colicin production, hemolytic activity, antibiotic resistance) was studied. The study revealed that the supernatants of S. boulardii decreased antilysozyme activity (ALA) in lactose positive (lac+) and lactose negative (lac-) Escherichia coli and Klebsiella strains, but produced no influence on ALA in Salmonella. In response to the action of S. boulardii exometabolites colicin production in E. coli (lac+) was found to increase, while in E. coli (lac-) colicin production was suppressed. An increase in the sensitivity of lactose negative E. coli to cefazolin and cefotaxime under the action of S. boulardii supenatants was noted. The results obtained in this study show the probable mechanism of the corrective action of "Enterol" on intestinal biocenosis, which should be taken into consideration in the differentiated selection of probiotics for the treatment of intestinal dysbacteriosis.