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In the course of the work done the specific and quantitative composition of the streptococcal autoflora of the fauces of the cosmonauts and the members of backup drew was investigated. In populations of isolated microorganisms the non-pathogenic streptococci have dominated among which S. salivarius prevailed. The same species has constantly been isolated in all the cosmonauts, pre- and postflight. Observation of the microflora state of the fauces at different stages of their professional activity made it possible to reveal the peculiarities of an individual dynamics in the number of nonpathogenic streptococci isolated from tampon depending on the participation of the test-subjects in the previous space missions. This is evidently a reflection of the effect of psychoemotional tension on the state of colonization resistance (CR) of the fauces mucosa and, as result of this, on its microflora. In turn, the occurrence of the individual species of conditionally-pathogenic streptococci after the mission points to a decrease in the CR under effect of unfavourable factors of space mission.

In the study of vaginal microflora in parturient women, carriers of group B streptococci (GBS), and those free of carriership a wide range of microorganisms, represented by aerobic and anaerobic species with the prevalence of lactobacteria in both groups of women, was isolated. The composition of vaginal microflora in parturient women did not depend on the presence of GBS in this biotope or on the level of colonization by lactobacteria. The colonization resistance (CR) of the vaginal mucosa had essential influence of the level of carriership with respect to GBS and a number of representatives of the symbiotic microflora of this locus. In the majority of cases GBS were isolated from parturient women with low CR.

Formation of microflora in the large intestine of 5-day old infants was studied in one of the Moscow maternity homes. The up-to-date procedures for isolation and identification of aerobic and anaerobic organisms were used in the study and the findings were processed on a computer. In the newborns of the maternity home of the "mother-infant" type there was observed colonization of the large intestine with aerobic and anaerobic organisms. A wave-like dynamics in the formation of the symbiotic microflora was revealed. It reflected the phenomenon of the microbial succession in the infants. The attempts to detect microbial interference between the species colonizing the large intestine showed that it was extremely rare in the 5-day old infants. This was likely the reason of the low intestine resistance to the colonization in the newborns which in its turn defined the frequent colonization of the intestine mucosa with S. aureus and the organisms of the Klebsiella, Enterobacter and Citrobacter group.

The formation of skin biocenosis in children under the conditions of a maternity hospital with the joint care of mother and child was studied with the use of commercial bacteriological imprints manufactured in the USSR. The colonization of newborn infants in maternity hospitals with opportunistic, saprophytic and normal microflora was established. In newborn infants aged up to 5 years low skin resistance to colonization and, as a consequence, frequent colonization of the skin with opportunistic and saprophytic microflora was observed.

The formation of microflora on the laryngeal mucosa in newborn infants during the first 5 days of their life was studied in one of the maternity hospitals of Moscow. In this work modern methods of the isolation and identification of aerobic and anaerobic microorganisms were used, and the results thus obtained were computer-processed. In the maternity hospital of the "mother-child" type the microbial colonization of the laryngeal mucosa by normal and opportunistic microorganisms was noted in newborn infants. A wave-like course of the formation of laryngeal microflora, indicative of microbial succession occurring in the child, was revealed. The attempt to establish the cases of microbial interference between the species colonizing the laryngeal mucosa revealed that it was very rarely observed in 5-day-old newborns. This feature was seemingly the cause of low resistance of the larynx to colonization in newborn infants, which determined frequent colonization of their laryngeal mucosa with Staphylococcus aureus and Klebsiella.

In a maternity hospital with the decentralized system of infant care the presence of the group B streptococcal colonization of puerperants (13.0 +/- 4.5%), newborn infants (25.0 +/- 4.4%) and medical staff (16.9 +/- 3.2%) was established. The strains isolated in this hospital belonged to 13 different serotypes and antigenic combinations with type 1 a/c dominating among them (28.7 +/- 4.8%). Group B streptococci were found to be transmitted by the vertical way in one out of two colonized mother-child pairs, in all other cases the nosocomial spread of streptococci occurred.

Based on the results of clinico-bacteriological and immunological studies carried out in the early neonatal period in 65 neonates afflicted with pyoinflammatory diseases and in their mothers, diagnostic criteria for intrauterine and early neonatal infection were elaborated. The significance played in this process of the character and level of microbial colonization of the amniotic fluid, placenta, labor tract of the mother, intrauterine antigenic stimulation of the fetus, changes in the peripheral blood and inflammatory alterations in the placenta was defined. Clinical, bacteriological and immunological prognostic criteria for the risk of the development of pyoinflammatory diseases in neonates were elaborated.

A study was made of the establishment of biocenosis in the early neonatal period in healthy full-term neonates born to healthy mothers and in children belonging to a group at risk with an aggravated anamnesis but with no history of pyoinflammatory diseases. The study was related to bacterial colonization of the mother, amniotic fluid and placenta as well as to the immune status of the lying in woman and fetus. In 37% of children belonging to the group at risk, the minimal signs of intrauterine infection were discovered.

Antagonistic and bacteriocinogenic activity was studied in 169 strains of meningococci of various serological groups and with different localization in the human organism at the time of isolation. Bacteriocinogenic activity was revealed in all the meningococcus strains (by delayed antagonism method), and, in addition, antagonistic activity was found in 100 strains. The inhibitory activity was the greatest in meningococci isolated from the cerebrospinal fluid. The data obtained suggest an important inhibitory activity of meningococci, along with their resistance to the antagonistic activity of the nasopharyngeal microorganisms, in the manifestation of pathogenic properties in them.

Comparative study of the meningococcus sensitivity of various serological groups with different localization in the human organism to the antagonistic activity of normal microbes of the nasopharynx and the antibiotics it was found that strains isolated from the cerebrospinal fluid of patients suffering from cerebrospinal meningitis, chiefly of serological group A, had the greatest resistance to the antagonists. Taking into consideration the leading epidemiological role of the cultures belonging to the serological group A in the USSR, it can be supposed that meningococcus sensitivity to the nasopharyngeal antagonists was of significance for the manifestation of their pathogenic properties. No association of the antibiotic sensitivity of the same strains with reference to a definite serological group or the site of the microbe localization was revealed.

The study of the species composition of hemophilic bacteria inhabiting the nasopharynx of healthy persons has revealed that H. parainfluenzae is the predominant species (82.0 +/- 4.8%) among these bacteria. The isolation of H. influenzae and H. parahaemolyticus has been found to occur considerably more rarely and in lesser numbers (9.0 +/- 1.5% and 3.8 +/- 1.0%, respectively). These data indicate that H. parainfluenzae should be regarded as the ecological dominant in the nasopharyngeal biocenosis, while H. influenzae and H. parahaemolyticus appear to be transitory microorganisms. Among the studied biochemical properties of hemophilic bacteria, the following properties have proved to be most stable: the reduction of nitrates, the splitting of glucose, sucrose, maltose, galactose, fructose and negative reactions as regards the formation of hydrogen sulfide, oxidase, the splitting of mannitol, sorbitol, lactose, xylose, arabinose.

Most of Str. salivarius strains isolated from the nasopharynx of healthy persons suppressed the growth of meningococci in vitro. Their antagonistic activity varied within a wide range, which suggested that different strains were unequal in their capacity for protection from meningococcal infection. The monthly comparison of the activity of various strains also allowed revealing considerable differences. These results confirm the earlier hypothesis on the decisive role of Str. salivarius in the protection of the nasopharynx from colonization by meningococci.

Observations on the manifestations of salmonellosis infection in various species of laboratory animals made it possible to establish general regularities inherent to this infectious disease, to reveal features depending on metabolic, morphological and microbiological characteristics of a given species of animals. These comparative data are of importance for understanding the factors determining resistance or sensitivity of the macroorganism to infection. Pathomorphological and microbiological investigations of experimental salmonellosis infection in hamsters and guinea-pigs showed that changes characteristic of this infection were manifested considerably weaker in guinea pigs than in hamsters. Of special interest were lesions of the large intestine mucosa wall in guinea pigs and those of the lungs in hamsters. These data may be a subject of a special study. Development and course of the experimental infection were not accompanied by the development of disbacteriosis. Pathogenic bacteria were eliminated on the 2nd--4th day in guinea pigs and on the 5--7th day in hamsters.

The comparative study of a large assortment of liquid and solid culture media used for the cultivation of streptococci in laboratory practice in the USSR and abroad was carried out with the aim of selecting the optimal media for the laboratory diagnosis of group B. streptococci. Liquid media were tested with the use of 7 streptococcal reference strains, and some of these media, found to yield the best results, were selected for tests on clinical material. The use of liquid accumulation media was shown to permit the isolation of group B. streptococcal strains which could not be detected by the direct inoculation of clinical material into dishes with blood agar. The character of hemolysis induced by group B. streptococci in solid media with 5% of blood added was found to depend on the composition of the medium and the conditions of cultivation.

Materials on the study of the colonization of newborns, their mothers and the medical staff of a maternity hospital by group B streptococci are presented. These streptococci were isolated from 26.3% of newborns, 19.6% of puerperae and 14.7% of the staff members. Group B streptococci were found to colonize different loci in newborns (the fauces, the nose, the umbilical cord, the ears, feces) and their mothers (the fauces, the vagina, the perianal fold, milk, the skin around the nipples, amniotic fluid, the umbilical cord). The serological typing of streptococci, isolated simultaneously from newborns and their mothers, suggested the presence of two possibilities of infecting the newborns with these microorganisms: (1) from their mothers and (2) from other newborns or members of the hospital staff during the stay in the maternity hospital.

Sensitivity of 125 strains of group B streptococci isolated from newborns, their mothers and personnel in a maternity home was studied with respect to 12 antibiotics: benzylpenicillin, ampicillin, methicillin, cephalotin, erythromycin, lincomycin, levomycetin (chloramphenicol), oxacillin, tetracycline, streptomycin, gentamicin and ristomycin. The method of serial dilutions in a solid medium was applied. All the strains were sensitive to ristomycin and erythromycin. The predominating number of the strains were sensitive to lincomycin, levomycetin and the beta-lactam antibiotics. Strains resistant or moderately resistant to benzylpenicillin, ampicillin, oxacillin, methicillin and cephalotin were detected. The majority of the strains were resistant to streptomycin, tetracycline and gentamicin. Multiple antibiotic resistance with 2-7 determinants was revealed in 11.2 per cent of the strains. The antibiotic sensitivity of the strains isolated from the newborns, their mothers and the personnel in the maternity home was on the whole similar or insignificantly differed.

Formulae for the calculation of the count of microorganisms isolated from natural bacterial biocenoses of a child's body have been derived. The authors suggest a variant of simplified drip method for the computation of microorganism colonies in solid media. The described method helps cut down the nutrient media consumption at least 3-fold and is time-saving.

A study was made of the species composition of symbiotic microbial flora of the nasopharynx in healthy persons and meningococcus carriers, inhibiting in vitro the growth of the test strains of miningococci. Saprophytic streptococci and particularly Str. salivarius served as the principal and the most active antagonists of meningococci in both groups of the persons examined. Comparison of the inhibitory activity of antagonists in the groups examined revealed no significant differences. However, there were seen differences in the quantitative composition of the isolated antagonists: saprophytic streptococci, particularly Str. salivarius were isolated in great amounts, and more frequently from healthy individuals, and nondifferentiated Gram positive cocci of conditionally distinguished group--from carriers. Taking into consideration the high inhibitory activity of Str. salivarius it is supposed that it can be used as an indicator of the state of insensitiveness of the human organism to the meningococcus infection.

Sensitivity of 56 streptococcal strains of group B to 12 antibiotics was studied with the method of dilution in a special solid medium for cultivation of streptococci and with the method of agar diffusion in the same medium. All the strains were found to be sensitive to chloramphenicol, ristomycin and erythromycin. The predominating majority of the strains were sensitive to beta-lactam antibiotics and lincomycin. All the strains were resistant to aminoglycoside antibiotics, such as streptomycin and gentamicin. More than 85 per cent of the strains were resistant to tetracycline. Strains with multiple resistance to 2-7 antibiotics were detected. Satisfactory correlation between the two methods was observed. It was shown to be clinically advisable to determine the sensitivity of streptococci of group B to beta-lactam antibiotics, erythromycin and lincomycin.

The coagglutination (COA) test is used for the serogrouping of streptococci, group B, and meningococci. The trial of a Soviet commercial preparation (staphylococcal reagent) has shown good prospects for its use in the COA test and high specificity of this test method. The availability of highly specific immune sera permits making standard kits for the identification of different infective agents in the COA test.

In a maternity clinic the circulation of group B streptococci among the newborns, their mothers and the personnel was established during the period of 1982-1985. Group B streptococci were detected at different biotypes of newborns (the pharynx, the imbilical stump, external suditory meatus, nasal and oral mucosa, eyes and feces), their mothers (the vagina, the perianal area, breast milk, the pharynx, urine, the umbilical cord, amniotic fluid) and in the pharynx of the personnel. In this maternity clinic 15 combinations of type antigens were detected, two combinations (1a/c and 1 b/c) prevailing among them. These results confirmed earlier data concerning two possible ways of transferring infection to newborn infants: vertical, i.e. from the mother to the child during parturition, and nosocomial, i.e. from contaminated newborns or members of the personnel.