Interrelations between Klebsiella ozaenae and other members of a microbial association in a pathological ozenous focus

The study of relationships between individual representatives of the microeubiosis at a pathological ozenous focus has shown that Gram-positive microorganisms and opportunistic enterobacteria are not antagonistic to K. ozaenae which, in their turn, do not affect the growth of opportunistic enterobacteria and Pseudomonas aeruginosa. The overwhelming majority of P. aeruginosa strains (92.9%) grown on a solid culture medium are characterized by a varying antagonistic activity with respect to K. ozaenae; this activity does not manifest if these organisms have been grown together in a liquid medium. P. aeruginosa culture fluid diluted 1:10 and 1:20 has not inhibited the multiplication of K. ozaenae. The data indicate the possibility of a prolonged coexistence of K. ozaenae with Proteus and P. aeruginosa, which is confirmed by many cases of simultaneous isolation of associations of these microbes from ozena patients. Thus the possibility appears of a combined pathogenic action of these bacteria on human body.     

Checking the reliability of the PathoTec biochemical test system for bacterial identification]

Tests of the PathoTec system intended for express bacteriological diagnosis were checked in comparative experiments with the common biochemical methods. Cultures of the following microbes were used: Schigella, Salmonella, Escherichia, Citrobacter, Klebsiella, Enterobacter, Proteus, Providencia, Pseudomonas, Bordetella, Staphylococcus, Streptococcus. In a number of tests, such as determination of cytochromoxidase, nitrate reduciase, phenylalaninedeaminase, indol, acetoin (for the differentiation of enterobacteria), detection of plasmocoagulation and mannite fermentation (for staphylococci) there was revealed a complete coincidence of the results. However, discrepancies were revealed with three of the reagents tested (for lysine decarboxylase, urease, citrate utilization) with regard to some groups of enterobacteria. The advantages of the PathoTec system consisted in more rapid results, simplicity of procedures, economy of media and ware.     

Intestinal microbiocenosis in children with intestinal enzymopathy

141 children with different kinds of intestinal enzymopathy were examined; of these, 33 had celiac disease, 39--the syndrome of celiac disease, 12--congenital lactase deficiency and 57--the syndrome of disaccharidase insufficiency. In these patients a significant decrease in the average characteristics of the main protective flora and the growth of hemolytic and lactose-negative enterobacteria were established. In all groups of patients increased amounts of Proteus were detected, which was indicative of profound dysbiosis. The content of bifidobacteria was found to be decreased in 89.5-97% of the patients and the content of lactic acid bacteria, in 15.8-33.3%. The decreased content of Escherichia coli with normal enzymatic activity (less than 10(7) colony-forming units) was noted in one-third of the patients with the syndrome of celiac disease and congenital lactase deficiency, in about a half of the patients with the syndrome of disaccharidase insufficiency and least of all in patients with celiac disease (9.1%). The association of opportunistic microbes was detected in 15.6% of the patients, more often in those with celiac disease, the syndrome of celiac disease and congenital lactase deficiency. The severity of disturbances in intestinal eubiosis was found to depend on the gravity of the patients' state.     

Flora of the purulent foci of patients at an orthopedic traumatology clinic and its sensitivity to antibiotics

A total of 4664 bacteriological analyses of the wound and purulent discharge from orthopedo-traumatological patients were performed within a 6-year period, i.e. from 1971 to 1976. Staphylococci were the dominating microbes of the purulent-inflammatory foci. Its part in the monoculture amounted to 64.5--82 per cent. The specific weight of the monocultures of various microbes decreased during the last 3 years, while the number of the microbial associations increased from 11.6 to 25.4 per cent Staph. aureus predominated in the inflammatory processes (65.8 to 86.5 per cent). Still, during the last 3 years the number of Staph. epidermidis increased from 16.8 to 26.2 per cent. The number of the so called "intermediate" or dissociated type of Staphylococcus, i.e. Staph. albus usually amounted to 7.5--8.1 per cent. In 1976 its number was 12.5 per cent. The pathogenic microbes of the coccal group were usually sensitive to erythromycin, monomycin, levomycetin and kanamycin. Among these microbes only staphylococci preserved their sensitivity to penicillin. The causative agents of purulent processes, i.e. Escherichia, Proteus, Pseudomonas were resistant to most of the antibiotics. Sensitivity to monomycin was preserved by 50 per cent only in Proteus. The microbial associations were mainly sensitive to monomycin and kanamycin.     

病原微生物致病岛的研究

致病岛是病原微生物通过基因水平转移获得的外源DNA,它是在研究致病性肠道菌的基因组结构和致病性的基础上发展起来的,并在其他革兰氏阴性和阳性致病菌中得到证实。本就各类病原菌致病岛的研究近况作一综述,同时介绍了致病岛的特征,讨论了致病岛在微生物进化中的意义及与tRNA基因的关系。     

O-antigens of bacteria of the genus Providencia: Structure, serology, genetics, and biosynthesis

The genus Providencia consists of eight species of opportunistic pathogenic enterobacteria that can cause enteric diseases and urinary tract infections. The existing combined serological classification scheme of three species, P. alcalifaciens, P. stuartii, and P. rustigianii, is based on the specificity of O-antigens (O-polysaccharides) and comprises 63 O-serogroups. Differences between serogroups are related to polymorphism at a specific genome locus, the O-antigen gene cluster, responsible for O-antigen biosynthesis. This review presents data on structures of 36 O-antigens of Providencia, many of which contain unusual monosaccharides and non-carbohydrate components. The structural data correlate with the immunospecificity of the O-antigens and enable substantiation on a molecular level of serological relationships within the genus Providencia and between strains of Providencia and bacteria of the genera Proteus, Escherichia, and Salmonella. Peculiar features of the O-antigen gene cluster organization in 10 Providencia serogroups and biosynthetic pathways of nucleotide precursors of specific monosaccharide components of the O-antigens also are discussed.     

Etiological structure of acute intestinal infections caused by opportunistic bacteria in young children

Altogether 587 children with diagnosed acute enteric infections were examined. In 26.4% of them pathogenic enterobacteria were detected, and in 59%, opportunistic enterobacteria. In 38.2% of children these bacteria were found to be the etiological factor of the disease. A reverse relationship between the contamination of feces with pathogenic enterobacteria and the age of children was established.     

Survival of enterobacteria in liquid cultures during microwave radiation and conventional heating

Bacteria in food have been reported to survive in larger numbers after processing by microwave radiation than after conventional processing. The bactericidal effect of a domestic microwave oven (SHARP R-7280) on certain pathogenic enterobacteria species was investigated in vitro, in comparison with conventional heating (boiling). The death rates of different nosocomial strains of Escherichia coli, Salmonella sofia, Salmonella enteritidis, Proteus mirabilis and Pseudomonas aeruginosa were tested. The microwave oven and the conventional heating system used were both calibrated in order to calculate temperatures from exposure times. For each strain duplicate samples of 25 ml of pure culture with concentrations at least 10(6) cfu/ml were exposed to microwave radiation. An equal number of samples of the same volume and concentration were exposed to conventional heating. Subsequently all samples were examined qualitatively and quantitatively following standard microbiological procedures. The results indicate that microwaves have an efficient bactericidal effect on the enterobacteria in liquid cultures.     

Study of the antibiotic sensitivity of the Shigellae, pathogenic Escherichia, Proteus and Staphylococcus isolated from young children in Tbilisi with acute intestinal diseases]

Sensitivity of Shigella, pathogenic Escherichia, Proteus and Staphylococcus isolated from children with acute intestinal diseases was studied with respect to antibiotics widely used in medical practice: streptomycin, levomycetin, tetracycline, chlortetracycline, oxytetracycline and neomycin. The antibiotic sensitivity was determined with the method of indicator discs. It was found that sensitivity of shigella was: 44 percent to streptomycin, 69.5 per cent to levomycetin, 18.5 per cent to tetracycline, 18.5 per cent to chlortetracycline, 23 per cent to oxytetracycline and 94 per cent to neomycin. Sensitivity of pathogenic Eschericia was 28, 33, 14, 14, 25 and 74 per cent, sensitivity of staphylococci was 46, 56.5, 21, 21, 31.5 and 89.5 per cent, sensitivity of Proteus was 15, 31.5, 3.5, 3.5, 7.5 and 52.5 per cent respectively. Cross resistance with respect to tetracyclines was found in all the microbes studie. Intragenera differences in the antibiotic sensitivity were observed among Shigella and pathogenic Escherichia.     

Characterization of epitope specificity of Proteus penneri 7 lipopolysaccharide core region

To extend the knowledge on the fragments of Proteus penneri lipopolysaccharide core regions, which determine the cross-reactions with specific antibodies, serological studies were performed by use of P. penneri 7 core-specific antiserum and Proteus sp. lipopolysaccharides. Different reactivity of the tested antiserum with three groups of antigens suggested differences in their core regions' epitope specificity. Comparing the results of the serological investigations with the previously determined structures of the core regions of the tested P. penneri lipopolysaccharides allowed distinguishing two potential tri- and tetrasaccharide epitopes and a third fragment which could not be determined precisely.     

Characterization of the cultivable microbiota of sprouts and their potential for application as protective cultures

The microbiota of ten seeds and ready-to-eat sprouts produced thereof was characterized by bacteriological culture and denaturing gradient gel electrophoresis (DGGE) of amplified DNA fragments of the 16S rRNA gene. The predominant bacterial biota of hydroponically grown sprouts mainly consisted of enterobacteria, pseudomonades and lactic acid bacteria (LAB). For adzuki, alfalfa, mung bean, radish, sesame and wheat, the ratio of these bacterial groups changed strongly in the course of germination, whereas for broccoli, red cabbage, rye and green pea the ratio remained unchanged. Within the pseudomonades, Pseudomonas gesardii and Pseudomonas putida have been isolated and strains of the potentially pathogenic species Enterobacter cancerogenes and Pantoea agglomerans were found as part of the main microbiota on hydroponically grown sprouts. In addition to the microbiota of the whole seedlings, the microbiota of root, hypocotyl and seed leafs were examined for alfalfa, radish and mung bean sprouts. The highest and lowest total counts for aerobic bacteria were found on seed leafs and hypocotyls, respectively. On the other hand, the highest numbers for LAB on sprouts were found on the hypocotyl. When sprouting occurred under the agricultural conditions, e.g. in soil, the dominating microbiota changed from enterobacteria to pseudomonades for mung beans and alfalfa sprouts. No pathogenic enterobacteria have been isolated from these sprout types. Within the pseudomonades group, Pseudomonas jessenii and Pseudomonas brassicacearum were found as dominating species on all seedling parts from soil samples. In practical experiments, a strain of P. jessenii was found to exhibit a potential for use as protective culture, as it suppresses the growth of pathogenic enterobacteria on ready-to-eat sprouts.     

D- and L-Aspartic Acids: New Non-sugar Components of Bacterial Polysaccharides

For the first time in bacterial polysaccharides, residues of D- and L-aspartic acids were identified as N-acyl substituents of 4-amino-4,6-dideoxy-D-glucose in the O-antigens of enterobacteria of the genera Providencia and Proteus.     

Methodological aspects of serological diagnosis in leptospirosis

The results of serological study for leptospirosis of 515 blood serum specimens from patients coming to different clinics of the Republic of Bangladesh, are presented. The sera were tested in microagglutination test. To exclude intergroup reactions and to enhance reliability of results, immunoglobulin classes were determined with the use of cysteine as a reducing agent and immunoabsorption test. In 51 patients (9.9%) antileptospiral antibodies were detected in titers from 1:20 to 1:1600 against pathogenic leptospires of different serological groups.     

Pyrazinamidase activity of bacteria from Enterobacteriaceae family as characteristic for taxonomy

Pyrazinamidase activity in 330 strains of bacteria from Enterobacteriaceae family (14 genus, 27 species) has been assessed. Pyrazinamidase activity detected in species from following genuses: Citrobacter, Escherichia, Klebsiella, Kluyvera, Morganella, Providencia, Raourtella, Salmonella, Shigella, and also in Proteus mirabilis, and nonpathogenic serovars of Yersinia enterocolitica, Y. frederiksenii. Pirasinamidase was absent in Serratia (S. marcescens, S. liguefaciens), Hafnia alvei, P. vulgaris, P. penneri, Y. pseudotuberculosis and pathogenic serovars of Y. enterocolitica. Absence of pyrazinamidase activity in bacteria from Hafnia and Serratia genus is a key taxonomic characteristic for identification of enterobacteria with microvolume assay technology.     

Distribution of pathogenic enterobacteria in the water of open reservoirs]

Investigations carried out indicated that the main source of microbial contamination of open reservoirs were effluents often drained without any purification and disinfection. Salmonellae were isolated in 10.6 +/- 0.88% of the water samples examined in the Southern regions of the country. Isolation of pathogenic enterobacteria from the water of open reservoirs was seasonal, with the maximal percentage in winter and in spring, this being connected with delay of self-purification processes in the cold seasons of the year. Serovars isolated from water and patients proved to be identical. There was no direct correlation between the coli index and the isolation of pathogenic enterobacteria.     

Sensitivity of the wound microflora of oncological patients to some new antibiotics]

Sensitivity of the microflora of the oncological patients' wounds to the new antibiotics, such as gentamicin, kanamycin, oxacillin, ampicillin and lincomycin was studied with the help of the disc method. The discs with the above antibiotics were prepared under laboratory conditions in accordance with the respective instructions in the WHO. Sensitivity of 429 bacterial cultures, including 98 cultures of pathogenic staphylocci, 45 cultures of Enterococci, 43 hemolytic streptococci, 143 cultures of Escherichia, 50 cultures of Ps. aeruginosa and 50 cultures of Proteus was determined. The studies showed that gentamicin was the most active antibiotic aganist all the microbial species isolated from the surgical and other wounds of oncological patients. It may be used in treatment of the infections caused by association of the microbes belonging to different species, as well as in treatment of purulent processes before elucidating their etiology, 16.7 per cent of the Enterococcal isolates were resistant to gentamicin. Monomycin, kanamycin, oxacillin, lincomycin and macrolide antibiotics at present are sufficiently active against pathogenic staphylococci and hemolytic streptococci.     

Dissemination of resistance plasmids among gentamicin-resistant enterobacteria from hospital patients.

Out of 184 patients who were infected or colonised with gentamicin-resistant enterobacteria, 17 (9%) harboured more than one strain. Single antibiotic-resistance plasmids were common to more than one of the different organisms isolated from nine patients, strongly suggestive of in-vivo conjugation. An "epidemic" plasmid with a molecular weight of approximately 110 megadaltons was found in 11 distinct strains isolated from four patients. Seven of the organisms harbouring this plasmid were Klebsiella aerogenes. Spread of multiple-resistance plasmids among endemic gentamicin-resistant enterobacteria is not uncommon, and these organisms provide a reservoir of plasmids that may ultimately spread to more pathogenic genera.     

Biological characteristics of Proteus strains isolated from water sources in the Azerbajiani SSR]

Biological characteristics of 102 Proteus strains isolated from the water bodies is given. The strains studied were referred to Pr. mirabilis, more rarely to Pr. vulgaris; about half of the cultures deviated from these biological types by the signs of indol formation and maltose fermentation. Proteus of groups O3, O5, O13, O23, and O30 were revealed in studying the serological characteristics. All the cultures were polyresistant, nonbacteriocinogenic; most of them were sensitive to the wide colicine spectrum. One strain produced a cytopathogenic action on the tissue culture.     

Intestinal enterobacteria of the hibernating Apis mellifera mellifera L. bees

Dynamics of enterobacteria of normal intestinal microflora was studied in Apis mellifera mellifera L. bees hibernating under snow in the Western Urals. The cell numbers (N) of the predominant species Klebsiella oxytoca increased from 10-10(6) CFU/bee in November 2004 to 10(4)-10(7) CFU/bee in March 2005; its frequency of occurrence (P) increased from 92 to 100%. Increase of Providencia rettgeri (11.2004: N up to 10(6), P 25%; 03.2005: N 10(2)-10(6), P 80%) was accompanied by the substitution of Morganella morganii (11.2004: N up to 10(6), P 25%) with Proteus vulgaris (03.2005: N up to 10(5), P 8%). By spring, Hafnia alvei and Citrobacter sp., which are pathogenic to bees, disappeared (11.2004: N up to 10(5), P 13 and 10%, respectively). Endophytic species Pantoea agglomerans, Leclecria sp., and other representatives of the "Enterobacter agglomerans" group were present in November and after the first emergence in spring (N up to 10(5); November: P 15%; April: P 23%). In April, the number of enterobacteria decreased to 10(5), and P. rettgeri became the predominant species (P 54%) instead of K. oxytoca (P 43%).     

Molecular Relationships Among the Salmonelleae

Polynucleotide sequence relatedness studies were carried out to determine the extent of divergence present in members of the tribe Salmonelleae and between salmonellae and other enteric bacteria. Typical Salmonella were 85 to 100% related. Two groups of biochemically atypical Salmonella showed somewhat lower binding to typical salmonellae and to each other. Arizona were 70 to 80% related to salmonellae. Two groups of Arizona were detected. These groups correlated with the presence of monophasic or diphasic flagellar antigens. Salmonella and Arizona were no more related to Citrobacter than to Escherichia coli (45-55%). Relatedness of Salmonella and Arizona to other enterobacteria ranged from 20 to 40% with klebsiellae and shigellae, to 20 to 25% with erwiniae, and to less than 20% with edwardsiellae and Proteus mirabilis.