Siberian peatlands a net carbon sink and global methane source since the early Holocene.

Interpolar methane gradient (IPG) data from ice cores suggest the "switching on" of a major Northern Hemisphere methane source in the early Holocene. Extensive data from Russia's West Siberian Lowland show (i) explosive, widespread peatland establishment between 11.5 and 9 thousand years ago, predating comparable development in North America and synchronous with increased atmospheric methane concentrations and IPGs, (ii) larger carbon stocks than previously thought (70.2 Petagrams, up to approximately 26% of all terrestrial carbon accumulated since the Last Glacial Maximum), and (iii) little evidence for catastrophic oxidation, suggesting the region represents a long-term carbon dioxide sink and global methane source since the early Holocene.

[Several aspects of non-clostridial anaerobic infection in cancer patients]. / Nekotorye aspekty neklostridial'noi anaérobnoi infektsii u onkologicheskikh bol'nykh.

The specific features of the development and natural history of nonclostridial anaerobic infection (NACI) were studied in 125 cancer patients with various site tumors. It was shown that after surgery for malignant abdominal and genital tumors, NCAI might develop in the late postoperative period despite antibacterial antianaerobic prevention and even long-term antianaerobic therapy. NCAI treated with antianaerobic therapy was found to run long with aggravations and remissions in patients undergone surgery and drug therapy for genital cancer. Radiation therapy is a risk factor for NCAI in patients with malignant genital neoplasms. The risk factors for NCAI in skin cancer patients are tumor ulceration, second infection, and resolution. The most severe problem is likely anaerobic bacteremia in cancer patients. Anaerobic bacteremia appears to be more common than we thought and this issue requires further in-depth study.

[The use of clindamycin and netilmicin for preventing postoperative wound infection in patients with cancer of the upper respiratory and digestive tracts]. / Primenenie klindamitsina i netilmitsina dlia profilaktiki posleoperatsionnoi ranevoi infektsii u bol'nykh rakom verkhnikh dykhatel'nykh i pishchevaritel'nykh putei.

Clindamycin (2.7 g/day) and netilmicin (5.6 mg/kg) were used for 6-10 days in 27 patients with laryngeal and oral cancer versus beta-lactam antibiotics and aminoglycosides received by 56 matched patients to prevent infection of the operative wound. Suppuration was observed in 11.1 and 41.4% of the patients, respectively (p < 0.05), the temperature rose over 38 degrees C in 22.2% and 42.9% of the patients, respectively (p < 0.05). The regimens showed similar toxicity. The findings proved high efficacy of clindamycin combination with netilmicin in infection prophylaxis in patients operated on for upper respiratory and digestive tract cancer.

[In vitro activity of a new glycopeptide antibiotic eremomycin in relation to obligate anaerobic Gram-positive bacteria]. / Aktivnost' in vitro novogo glikopeptidnogo antibiotika éremomitsina v otnoshenii obligantnykh anaérobnykh gram- polozhitel'nykh bakterii.

Antibacterial activity of eremomycin, a novel glycopeptide antibiotic, against obligate anaerobic Gram-positive++ bacteria was studied. Eremomycin was shown to inhibit the growth of obligate anaerobic Gram-positive++ cocci and bacteria belonging to Clostridium in rather low concentrations and within narrow ranges of the MIC which was indicative of the antibiotic undoubted advantages. The antibacterial activity of eremomycin was 2 times as high as that of vancomycin and 8 times as high as that of ristomycin with respect to Gram-positive++ anaerobic cocci. Pathogenic strains of Clostridium spp. were 2 to 4 times more sensitive to eremomycin than to vancomycin. A significant property of the novel glycopeptide antibiotic was shown to be its capacity for inhibiting the growth of Gram-positive++ aerobic and obligate anaerobic cocci within the same concentration ranges which might be of importance in monotherapy of mixed aerobic and anaerobic infections.

[Characteristics of wound infection in long-term crush syndrome]. / Osobennosti ranevoi infektsii pri sindrome dlitel'nogo razdavli- vaniia.

Clinicobacteriological examination was carried out in 31 patients with the crush syndrome (CS) and extensive damage to the soft tissues in combination with bone fractures complicated by wound infection. Inadequate surgical treatment in the early periods after the trauma (complete closure of the wound, making small incisions of the involved skin and subcutaneous fat) is particularly hazardous in such cases because it leads to the development of severe wound infection. This disease is marked by a complex polymicrobial structure of the causative agents, massive dissemination of aerobic and opportunistic anaerobic bacteria in the purulent focus (10(7)-10(9) microbial bodies), and a high proportion (48.4%) of obligate anaerobic microflora. Wound infection in the CS takes a grave clinical course, but without profound microbiological study it is difficult to differentiate it into aerobic and anaerobic (clostridial and ++non-clostridial) forms. This is evidence of the need for emergency extended bacteriological diagnosis at all the stages of treatment. "Pure" aerobic infection was identified in half of the patients and mixed aerobic-anaerobic infection in the other half. The possibility of the involvement of asporogenic anaerobes is shown (35.5% of cases). The high risk of the development of gas gangrene is detected (9.7%) and its is concluded that early prevention is necessary by adequate surgical intervention, adequate intensive antibacterial and detoxification therapy, including hyperbaric therapy. The efficacy of current antigangrene immunization agents must be evaluated.

[Empirical antibiotic therapy of wounds complicated by anaerobic non-clostridial infection]. / Empiricheskaia antibiotikoterapiia ranevogo protsessa, oslozhnennogo anaérobnoi neklostridia'lnoi infektsiei.

Antibacterial activity of 14 drugs against clinical strains of asporogenic anaerobes causing wound infections in the soft tissues i. e. Bacteroides fragilis and Bacteroides melaninogenicus as well as anaerobic gram-positive++ cocci was assayed with the method of serial dilutions in agar. It was shown that among the investigated species B. fragilis had the most marked resistance since out of the 14 drugs only 8 were sufficiently active against it i.e. carbenicillin, levomycetin, lincomycin, dioxidine, metronidazole, thinidazole, nitrazole and erythromycin. The choice of drugs for treating infections caused by B. melaninogenicus and anaerobic grampositive cocci unlike those caused by B. fragilis offered no difficulty since practically++ all the investigated drugs were highly active against the causative agents. There was observed relationship between the frequency of asporogenic anaerobes and the wound genesis. The characteristic features of the species composition connected with localization of the suppurative foci were indicated. The detected specific antimicrobial profiles of the asporogenic anaerobes causing wound infections and the peculiarity of their participation in development of purulent infections of the soft tissues provided a differential approach to empirical antibacterial therapy prior to the pathogen bacteriological investigation and availability of the antibioticograms.

[Nonclostridial obligate anaerobes--the main causative agents of lung abscesses]. / Neklostridial'nye obligatnye anaéroby--osnovnye vozbuditeli abstsessov legkikh.

The use of the anaerobic technique in bacteriological investigations has made it possible to establish the leading role of asporogenous anaerobes in the etiological structure of the causative agents of pulmonary abscesses. Asporogenous anaerobes have been isolated from 93% of all examined patients, and in 54.4% of such patients these microorganisms have proved to be an independent etiological factor. Among asporogenous anaerobes, the main causative agents of pulmonary abscesses have been found to belong to four genera: Bacteroides, Fusobacterium, Peptococcus and Peptostreptococcus. Pulmonary abscesses of purely aerobic etiology are rather rare (5.3%). The schemes of the antibacterial treatment of patients with pulmonary abscesses, developed with regard to the leading etiological role of asporogenous anaerobes and clinically approved, have permitted achieving a considerable improvement in the results of treatment and an essential economic effect.

[Bacteria of the species Acinetobacter calcoaceticus as the possible etiological factor in infectious complications in burns]. / Bakterii vida Acinetobacter calcoaceticus kak vozmozhnyi étiologicheskii faktor infektsionnykh oslozhnenii pri ozhogakh.

The results of the study of the etiological role of Acinetobacter calcoaceticus in infectious complications of burning lesions are presented. These bacteria were shown to occur in 28% of burn wounds, quite frequently as a monoculture or association with diphtheroids. A. calcoaceticus were capable of persisting in the wounds during the whole period of treatment (up to 2-3 months). A high level of the contamination of burn wounds with these microorganisms, reaching 10(5)-10(6) cells per 1 g of tissue or 1 cm2 of the wound surface, was observed. The occurrence of A. calcoaceticus in the blood of the patients from whose burn wounds these microorganisms could be isolated was 36.3%. All isolated strains possessed multiple drug resistance.

[Antibiotic sensitivity of Acinetobacter calcoaceticus in patients with infected burns]. / Antibiotikochuvstvitel'nost' Acinetobacter calcoaceticus u bol'nykh s infitsirovannymi ozhogami.

Sensitivity of Acinetobacter calcoaceticus var. anitratum isolated from infected burn wounds was studied with respect to 24 antibiotics. It was found that the isolates were multiple drug resistant. Sensitivity was observed at least to 8 out of 24 antibiotics. The majority of the isolates were resistant to 10--15 drugs. Many strains were resistant to 16--17 antibiotics. 11 antibacterial drugs, i. e. tobramycin, sisomicin, gentamicin, amicacin, neomycin, carbenicillin, polymyxin M, erythromycin, tetracycline, rifampicin and dioxidine proved to be most active against Acinetobacter calcoaceticus. The strains were resistant to 6 antibiotics, i. e. penicillin, oxacillin, lincomycin, ceporin, fusidin and ristomycin. The activity of streptomycin, ampicillin and levomycetin was negligible.

[Biological properties of Cl. perfringens type A, isolated from human subjects inhabiting a hermetic chamber]. / Issledovanie biologicheskikh svoistv Cl. perfringens tipa A, vydelennykh u liudei v usloviiakh prebyvaniia ikh v germeticheskoi kamere

This paper gives the results of quantifying and studying the biological properties of Cl. perfringens strains isolated from feces of test subjects kept in an enclosure for 34 days. During the experiment the total number of Cl. perfringens increased. It was especially true of the strains with an elevated toxigenic activity. This activity correlated with an increase of the titer of alpha-hemolysines and proteolytic enzymes.

[Serologic properties of strains of Cl. perfringens isolated from the intestinal contents of healthy subjects]. / Izuchenie serologicheskikh svoistv shtammov Cl. perfringens, vydelennykh iz kishechnogo soderzhimogo zdorovykh liudei

A study was made of the quantitative content in the intestine of C1. perfringens strains in 6 healthy persons who stayed in a hermetically sealed space for 1 month and for 1 year. C1. perfingens strains were isolated from the fecal samples of each of the volunteers at various periods of the trial. A total of 570 strains of C1. perfringens of type A with anticellular sera obtained to the strains of various serological groups were studied. Serological properties of C1. perfringens strains of type A present in the intestinal contents of man were nonhomogeneous. This pointed to the simultaneous presence in the intestine of strains belonging to several serological types. A partial or complete replacement of one strain by another (differing by serological properties) occurred in the course of not over one month. C1. perfringens strains of type A present in the intestine of each volunteer were subdivided into serological types individual for each of the persons under observation. This pointed to the fact than no interexchange of strains of the mentioned bacteria occurred between different persons in the hermetically sealed space.

Changes in the microflora of man during long-term confinement.

Extended space missions may change the human normal microflora, including the intestinal flora. The bacterial composition of the intestinal microflora is an important factor in natural resistance to infection. During the year-long medico-engineering experiment human intestinal microflora was thoroughly studied. It was necessary to collect more detailed information concerning the composition in healthy people. 83 microbiological tests of faeces of 27 healthy male subjects were carried out. It was found that spore-less anaerobic bacteria predominated in the fecal microflora, reaching 90% of total micro-organisms. Aerobic micro-organisms were less than 6% of total micro-organisms. Long-term enclosure of men was shown to induce changes in the intestinal microflora which involved a sharp reduction of different microbial groups, and occasionally complete elimination of certain representatives of the intestinal flora. The composition tended to be simplified. A study of the isolated cultures of Cl. perfringens demonstrated an increased amount of strains with toxicogenic properties. Staphylococci were isolated from the test subjects during their long-term enclosure. The pharynx and nose of the three test subjects were examined and 1445 staphylococcal strains were isolated, of which 745 strains (51.5%) were coagulase producers. In 745 strains phage-type, coagulase, toxicity, hemolysins, lecitinase, fibrinolysin and DNA-ase were determined. Phage-typing of the isolated staphylococci revealed a microbial exchange between the men. Staphylococcal strains of the same phage-type (29/52) isolated during the experiment showed an increase of the toxin titre (from 1:40-1:80 to 1:640-1:1280) and development of additional pathogenic properties that were not found previously. An increase in beta-hemolysin and fibrinolysin production and an acceleration of DNA-ase activity. Experiments on mice demonstrated increased virulence of the staphylococcal strains isolated by the end of the experiment. The data are discussed from the point of view of the immunological responses of the human body.