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At least 307 records · Page 17Linked to original sources
PubMed1985

[Distribution of microorganisms lysing Pseudomonas aeruginosa and Staphylococcus aureus in the system of sewage waters].

The regularities of lytic microorganisms distribution in domestic sewage have been studied. A reproduction of mesophilic gram-negative bacteria producing lytic substances against Pseudomonas aeruginosa and Staphylococcus aureus has been shown to take place at mechanical cleaning stages. In the primary sediment trap the number and the relative content of microorganisms lysing P. aeruginosa at mean temperature and the number of microorganisms lysing S. aureus are maximum. The number of gram-positive sporogenous bacteria lysing P. aeruginosa under conditions close to thermophilic does not change considerably till the secondary sediment trap and remains comparatively high. Certain stages of purification can be regarded as a source of microorganisms producing lytic substances.

Bacteriolysis↗
PubMed1986

Chorioamnionitis and the isolation of microorganisms from the placenta.

Specimens for the isolation of microorganisms were obtained from the cervical canal in 83 and from the placenta in 86 of 90 women delivered by cesarean section. In addition, the placentas from 87 of these women were examined histopathologically. No correlation was found between the isolation of a given microorganism from the cervical canal and infectious disease in mothers and/or neonates. Isolation of microorganisms from the placenta was correlated with rupture of the membranes occurring six or more hours before surgery and, in women with intact fetal membranes, was correlated with uterine activity. Chorioamnionitis histopathologically was associated with maternal and/or neonatal infections and prematurity. Microorganisms were not isolated significantly more often from the placenta in cases with chorioamnionitis than without. The value of cervical and placental cultures in predicting intrauterine infection is questionable.

Bacteria↗
PubMedDate not supplied

[Physiology of xerophytic microorganisms that grow under very dry conditions].

The biology of xerophytic microorganisms surviving and growing under conditions imitating Martian ones was studied, as well as the zone of tolerance of several microorganisms towards the activity of water. The xerophytic nature of microorganisms is suggested to be evaluated by means of quantitative determination, using gas chromatography, of carbon dioxide which is evolved when microorganisms are cultivated on media with different values of aw.

Aspergillus↗
PubMedDate not supplied

[Lipolytic activity of microorganisms isolated from different sources].

From different natural sources (samples of raw and pasteurized milk, fresh and melted butter, cheese, industrial and nonindustrial sewage containing fats and surface active substances) 650 microorganisms were isolated. Measurements of their lipolytic activity on milk fat (20% cream), tristearin and olive oil indicated that 27 microorganisms had no lipolytic activity on either substrate. A hundred cultures showed the highest activity. Out of them 40 most active cultures belonging to different systematic groups (fungi, yeast, bacteria) were identified as representatives of certain genera or species. Lipolytic activity varied significantly in microorganisms belonging to the same species. The use of several substrates (cream, tristearin, olive oil) helped to discriminate microorganisms that preferentially hydrolyzed either substrate.

Animals↗
PubMed1983

Unsuitability of blood culture media containing sodium polyanetholesulfonate for the detection of fastidious microorganism in CSF and other blood-free body fluids.

The suitability of well known conventional blood culture media for the detection of microorganisms in CSF and other blood-free body fluids has been tested. It was demonstrated that such media are unsuitable for the cultivation of fastidious and/or anticoagulant-sensitive microorganisms which are frequently isolated from CSF and other blood-free body-fluids. On the contrary, the recently-developed MOPS electrolyte broth A which proved to be a suitable cultivation and back-up medium for aerobic and facultative anaerobic microorganisms in CSF and other blood-free body fluids is not suitable for the detection of microorganisms in blood, because it is free of anticoagulants.

Aerobiosis↗
PubMed1983

[Factors affecting the viability and properties of microorganisms in different preservation methods].

The review of literature devoted to the influence of the different methods of longterm preservation on the survival, physiological and biochemical properties of microorganisms: at low and ultralow temperatures, freeze-drying, drying, storage under the mineral oil etc. is given. The microorganisms viability depends on their nature, age and density of population, storage and recovery conditions of cells. Some features of the industrial microorganisms storage have been marked. The different hypotheses concerning the mechanism of preservation, injury and reactivation of microorganisms under the action of external factors during their storage are being discussed.

Bacterial Physiological Phenomena↗
PubMed1984

[The isolation and identification of microorganisms capable of using agricultural wastes resistant to enzymatic degradation].

Feather which is an agricultural waste and resistant to enzymatic degradation has been used as a substrate for microorganisms. Some microorganisms using this material have been isolated and identified. Total 13 microorganisms, the optimum growth temperature of which are 30 degrees C and 50 degrees C have been isolated. After colonial and microscopic examinations, it has been observed that 12 of these microorganisms are of the Bacillus genus. By means of further biochemical tests all Bacillus genera have been identified at species levels. It has been also observed that the keratinase activities of these Bacillus species are different.

Agriculture↗
PubMed1983

Betalactamase-producing microorganisms in recurrent tonsillitis.

In 73% of 167 patients with recurrent tonsillitis, colonization with betalactamase-producing microorganisms was found. Betastreptococci group A were recovered in 6% of the patients and group C and G streptococci in 23%. Other microorganisms found were Staphylococcus aureus in 42%, Haemophilus species in 52%, bacteroides species in 80% and fusobacteria in 40%. Ninety-eight per cent of Staph. aureus, 60% of bacteroides species and 10% of fusobacteria were betalactamase-producing. Phenoxymethylpenicillin (1 g twice a day for ten days) diminished 50% of group A, C and G streptococci. No other microorganisms were affected by this antibiotic. Clindamycin (0.15 g four times a day for ten days) eradicated Staph. aureus, group A, C and G streptococci, bacteroides and fusobacteria. Haemophilus species were not affected by clindamycin. Tinidazole (1 g once a day for 10 days) diminished bacteroides and fusobacteria. Aerobic microorganisms, Staph. aureus, streptococci and Haemophilus, were not affected by tinidazole.

Adolescent↗
PubMedDate not supplied

[Growth kinetics of microorganisms with various ecological strategies in a dialysis culture at low specific growth rates].

A dialysis culture was found to be most suitable for studying the metabolism of microorganisms at a low specific growth rate. The biomass of all microorganisms studied in the dialysis culture increased with time in a linear fashion; hence, the energy spent for growth decreased in proportion to a decrease in the specific growth rate. Microorganisms growing in oligotrophous environment (Arthrobacter globiformis and Lipomyces tetrasporus ) spent much less energy comparing to microorganisms from eutrophic habitats (Pseudomonas fluorescens and Debaryomyces formicarius ).

Arthrobacter↗
PubMed1983

A study on heifer mastitis in Japan and its causative microorganisms.

Survey and bacteriological examination were conducted on heifer mastitis in Hokkaido, the northern island of Japan over a period from 1976 to 1981. The disease occurred in heifers, mostly 13 to 18 months old, less than a half of which was pregnant in late summer or in August and September. Infection occurred predominantly in a front quarter than a rear one. Some microorganisms were isolated by the CO2 gas jet method from all the 74 secretions from the affected quarters of 67 heifers. Actinomyces pyogenes ( Corynebacterium pyogenes) was isolated from 49 secretions (66.2%), forty-six of which were involved in mixed infection with other microorganisms, including Peptococcus indolicus that was found in 41 secretions. Streptococcus dysgalactiae was isolated from 13 secretions, from nine of which were obtained pure cultures. The microorganisms harbored in secretion were much more closely associated simultaneously with A. pyogenes and P. indolicus than with A. pyogenes alone or a combination of A. pyogenes and any other microorganism than P. indolicus . This is the first report that P. indolicus was isolated from heifer mastitis in Japan. The "score" used for the expression of quality of milk secretion seemed to be useful for the clinical diagnosis of heifer mastitis. The disease in Hokkaido may be etiologically identical with summer mastitis found in the northern European countries.

Actinomyces↗
PubMed1982

A search for new microorganisms in calf pneumonia by the inoculation of gnotobiotic calves.

In a detailed microbiological and pathological study of eight outbreaks of calf pneumonia, which included the inoculation of respiratory material into 18 gnotobiotic calves, a total of five viruses, four species of mycoplasma and 19 species of bacteria were identified. The only microorganism not previously associated with bovine respiratory disease was a coronavirus. The experimental disease produced in the majority of the gnotobiotic calves by the intratracheal inoculation of unpassaged respiratory material, closely resembled the natural disease. However statistical analysis of the results could not ascribe the disease seen to a single microorganism or to a particular combination of microorganisms. Assuming therefore that no microorganisms were missed in the study, it was concluded that the microbiological cause of the experimental disease lay amongst the organisms already found and that one or more of three other factors, discussed in the paper, accounted for the experimental disease produced.

Animals↗
PubMed1981

Action of clinically utilized 5-nitroimidazoles on microorganisms.

Various nitroimidazoles are used as antimicrobial and radiosensitizing agents in human medicine. Of these, 5-nitroimidazoles show high selective toxicity for anaerobic prokaryotes and eukaryotes. This review discusses the effects of 5-nitroimidazoles on microorganisms, i.e. microbicidal action, radiosensitizing action, inhibition of photosynthetic microorganisms, and induction of mutations. All these actions are enhanced by anaerobiosis and inhibited by aerobiosis or by the presence of certain reducible compounds. There is no indication that antimicrobial action could be dissociated from mutagenic properties. Relative resistance to 5-nitroimidazoles has been detected in some isolates of Bacteroides fragilis and Trichomonas vaginalis and was experimentally developed in B. fragilis and various trichomonads. Nitroimidazoles enter the microorganisms by diffusion. Facilitated transport has not been detected. The compound is reduced by low oxidation-reduction potential ferredoxin and similar electron transport components in the cell. In microorganisms highly susceptible to metronidazole, such compounds play a significant metabolic role. The reduction increases the outside-inside concentration gradient and thus drives further uptake. Certain short-lived products of the reduction are responsible for the cytotoxic action. In less susceptible organisms only limited amounts of such products are formed, and thus the cells are not killed but may undergo mutations. A major component of cytotoxicity is damage to DNA but other mechanisms cannot be excluded at present.

Anaerobiosis↗
PubMedDate not supplied

[Determination of the chitinolytic activity of "Abies alba" Mill. litter microorganisms: bacteria and yeasts (author's transl)].

Chitin decomposition by some microorganisms isolated from Abies alba Mill. litter has been observed. The active strains were representatives of the genera Bacillus, Pseudomonas and Streptomyces. The isolated yeasts were unable to decompose chitin. The chitinolytic microorganisms secreted in medium an extracellular chitinase system which determined chitin hydrolysis. Cell-free culture filtrate of the microorganisms produced colloidal chitin hydrolysis. An estimation method of chitin hydrolysis was determined measuring chitin loss in standard conditions. Experimental results indicate that Pseudomonas isolate is the most active. The active strains represent about 15% of the microorganisms, bacteria and yeasts, isolated from this litter.

Bacillus↗
PubMedDate not supplied

Biocorrosion produced by Thiobacillus-like microorganisms.

Biocorrosion can be produced by many different microorganisms through diverse mechanisms. The biocorrosion produced by acidophilic microorganisms of the genus Thiobacillus is based on the production of sulfuric acid and ferric ion from pyrites or related mineral structures, as a result of the chemolithotrophic metabolism of these microorganisms. The products of this aerobic respiration are also powerful oxidant elements, which can produce chemical oxidations of other metallic structures. The Tinto River, a very unusual extremophilic habitat (pH around 2, and high concentration of ferric ion), product of the growth of strict chemolithotrophic microorganisms, is discussed as a model case.

Biodegradation, Environmental↗
PubMedDate not supplied

[Nuclease activity of microorganisms and control of auto-microflora state of operators in hermetically sealed environment].

A study was performed to investigate biological properties of pathogenic microorganisms (Shigella, Salmonella, Staphylococcus aureus) and potentially pathogenic microorganisms which were isolated from different people, i.e. clinically healthy people with normal microflora, somatically healthy patients with intestinal dysbacteriosis, and patients with acute intestinal diseases. The most important parameters of pathogenicity typical of the basic representatives of pathogenic microflora were DNA and/or RNA forming activity. The "critical" size of depolymerization zones of nucleic acids on dense nutrient media was found to be equal to 2 mm and greater from the colony edge. The critical size was shown to be significantly different in potentially pathogenic and normal intestinal microorganisms. Maximal microbial concentrations in the major biotopes of man were estimated to be: no more than 25%, 5% and 2% for nasal mucosa, back skin, and for the large intestine of the total amount of microorganism in the test. Verification of the method gave evidence that in can be applied for an alternative evaluation of automicroflora of the large intestine of operators in an enclosed environment. It is suggested that the normal parameters characteristic of clinically healthy people need to be verified and applied in space and undersea medicine.

Adult↗
PubMedDate not supplied

A bacterial sensitivity test to determine the effectiveness of minocycline HCI (Minocin), erythromycin (Erythrocin) and ampicillin (Ampicin) on the predominant microorganisms present in a diseased periodontium.

The purpose of this study was to determine the effectiveness of the three antimicrobials--Minocycline HCI, Erythromycin and Ampicillin based on the percentage reduction of bacteria present in subgingival microflora and in vitro assessment of antibiotic susceptibility of cultured strains of predominant microorganisms present in a diseased periodontium. Twelve volunteers 18 to 65 years of age, with moderate to severe periodontal disease, were randomly divided into Group A and Group B of 6 members each. Oral lavage procedure was performed to Group A and Group B received systemic administration of antibiotic for five days. Patients 1 & 2, 3 & 4 and 5 & 6 received minocycline HCI, Erythromycin and Ampicillin respectively. Microbiologic samples in the subgingival crevicular area in selected tooth exhibiting clinical periodontal breakdown were obtained from all the subjects prior to and after the oral lavage procedure and systemic drug administration. Streptococcus viridans is the most predominant aerobic microorganism obtained from 83% of samples. However no anaerobic microorganism has been isolated. Bacterial sensitivity testing showed 60% of samples with positive growth of microorganisms (S. viridans) were also equally sensitive to Minocycline HCI, Erythromycin and Ampicillin. Oral lavage proved to be ineffective in reducing the number of bacteria. However, systemic drug administration revealed that there was a reduction in bacterial count after taking such antibiotics for five days which is more favorable to Minocycline HCI.

Adolescent↗
PubMed2026

Environmental Release of Genetically Intervened Microorganisms: Towards a New Narrative.

The deliberate release of genetically engineered microorganisms for environmental applications has remained largely blocked since the early days of recombinant DNA technology, when limited ecological knowledge, lack of success stories and public apprehension shaped a culture of caution and restrictive regulation. Despite profound advances in microbial ecology, synthetic biology and genetic design, current frameworks still rely on outdated assumptions and legacy regulations that equate engineered microbes with inherent danger and demand unrealistic forms of absolute containment. This review examines how laboratory-trained microorganisms exist on a continuum with naturally evolved life, and that their risks are neither categorically different nor greater. Rather than pursuing unachievable containment, governance should shift towards traceability, stewardship and long-term monitoring through genomic barcodes, digital twins and transparent oversight. The vision moves from domination and control to care and partnership recognizing engineered microbes as live amendments capable of restoring degraded ecosystems. Achieving this transformation requires new terminology, phased field-trial frameworks, improved scaling methods, and the integration of epistemological perspectives that emphasize reciprocity and coexistence with nature. Reframing biotechnology in this way could finally unlock the capacity of engineered microorganisms to contribute responsibly and effectively to planetary repair in an era of escalating environmental crises.

Microorganisms, Genetically-Modified↗
PubMed2001

Bioactive glass S53P4 in repair of septal perforations and its interactions with the respiratory infection-associated microorganisms Haemophilus influenzae and Streptococcus pneumoniae.

Interpositional grafts between mucoperiosteal flaps are commonly used in the repair of septal perforations. We studied the use of bioactive glass (BAG) S53P4 as an interpositional graft in 11 patients suffering from septal perforations. In aqueous environments, ions are released from the BAG and the pH rises in its vicinity, both of which may influence the growth and adhesion of microorganisms. Thus, we also studied the effects of the BAG S53P4 as granules or discs on the respiratory infection-associated microorganisms Haemophilus influenzae and Streptococcus pneumoniae. Growth inhibition was studied using an agar plate test and adhesion was analyzed both with and without serum precoating of the BAG S53P4. The perforations were successfully closed in 10 of 11 patients. One patient had a near total septum perforation, which could not be closed. No BAG-associated infections were seen during the follow-up. The BAG S53P4 did not show any clear growth inhibition of the microorganisms, which showed low adhesion to the material. Serum precoating increased the adsorption. Thus, uncoated BAG S53P4 seems to be a good graft in the repair of septal perforations.

Adult↗