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PubMedDate not supplied

[Distribution and physiology of microorganisms in petrochemical oily sludge of plant].

The occurrence, vertical distribution, and the physiological state of microorganisms in a petrochemical oily sludge deposit were studied. The total number and the number of viable microbial cells at depths of 0.2 and 3 m were about 10 and 10(8) cells/g dry wt. sludge. Most microbial cells taken from the middle (1 m deep) and the bottom (3 m deep) sludge horizons showed a delayed colony-forming ability, which suggested that the cells occurred in a hypometabolic state. The relative number of microaerobic denitrifying microorganisms steeply increased with depth. The amount of microorganisms tolerant to 3, 5, and 10% NaCl and capable of growing at 7 and 40 degrees C varied from 10(2) to 10(8) CFU/g dry wt. sludge. Petrochemical oily sludge was found to maintain the growth of heterotrophs, among which the degraders of oily sludge and ten different individual polycyclic aromatic hydrocarbons were detected. The occurrence of highly adaptable microorganisms with an adequate metabolic potential in the petrochemical oily sludge deposit implies that its bioremediation is possible without introducing special microorganisms.

Bacteria↗
PubMed2003

[Evaluation of microorganisms ability to beta-lactamase production in exacerbation of chronic sinusitis treated with beta-lactam antibiotics].

In our study the ability of the isolated microorganisms to produce beta-lactamase was determined. These microorganisms were isolated from sinus punctures of 115 patients before (evaluation I) and after the treatment finished (evaluation III). During first evaluation 93 microorganisms with potential ability to beta-lactamase production were isolated. 24 of them (25.81%) produced beta-lactamase, 69 (74.19%) didn't do it. 57 patients were qualified for amixycillin with potassium clavulanate treatment (subgroup A) and 58 patients for cefuroxime axetil treatment (subgroup B). After the treatment (evaluation III) in the group of 21 isolated microorganisms 6 produced beta-lactamase. The microorganisms producing beta-lactamase were isolated only from the patients where the amoxycillin with potassium clavulanate was administered.

Cefuroxime↗
PubMedDate not supplied

[Comparative characteristics of the numbers of microorganisms in soils and their basement sedimentary rocks].

Comparative studies on the quantitative composition of microorganisms in soils and basement sedimentary rocks have shown that the latter are rich in microorganisms. The number of microorganisms in basement grounds changes with time, thus indicating their activity. The qualitative composition is poor. At the same time, the total quantity of microorganisms in basement layers is equal to that in soil. Basement layers contain 10 times more microorganisms than eutrophic water reservoirs and 1000 times more than oligotrophic water reservoirs.

Geological Phenomena↗
PubMed2005

DNA assays for detection, identification, and individualization of select agent microorganisms.

The purpose of this article is to review the status of DNA assays used for the detection, identification, and individualization of Bacillus anthracis, Yersinia pestis, Francisella tularensis, Burkholderia mallei, and Brucella abortus. These select agent microorganisms are historically significant as they have either been used or experimented with as a bioweapon or as a terrorist agent and are the subject of intense research in the areas of biodefense and bioforensics. If the presence of a biological agent is suspected, sensitive and specific assays for rapid detection and identification are necessary. However, DNA methods for identification of the sample may also be applied in order to individualize the strain and potentially determine the source of the microorganism. Methods used at the Armed Forces Institute of Pathology (AFIP) for select agent microbial DNA analyses include DNA extraction, DNA quantitation, real-time polymerase chain reaction (real-time PCR) of genetic targets unique to the select agent microorganism, microbial 16S ribosomal RNA gene DNA sequencing, amplified fragment length polymorphism polymerase chain reaction (AFLP-PCR), and more recently, repetitive element polymerase chain reaction (REP-PCR) DNA fingerprinting. The methodologies of 16S ribosomal RNA gene DNA sequencing and DNA fingerprinting of microorganisms are well established within the field of diagnostic microbiology for DNA identification purposes, as well as DNA typing for epidemiological and genetic relatedness studies. 16S ribosomal RNA gene DNA sequencing and AFLP DNA fingerprinting have been validated at the Armed Force Institute of Pathology (AFIP) laboratory for identification purposes and can be used as a possible strain typing tool for Bacillus anthracis, Yersinia pestis, Francisella tularensis, as well as Brucella and Burkholderia species. The continued development and implementation of new DNA based methods with increased sensitivity and defined specificity will be particularly useful for the detection of residual microbial DNA signature in situations where the microorganism has been rendered nonviable by decontamination procedures or not able to be cultured on microbiological media.

Biological Warfare↗
PubMed1994

Isolation, identification and sensitivity pattern of microorganisms isolated from the urine of pregnant women.

The present studies were conducted to detect and identify the microorganism from the urine of pregnant women having urinary tract infection. The antibiotic susceptibility of these isolated microorganisms was also determined. The microorganisms found responsible for the infection were bacteria, fungi, yeast and protozoa. Among the bacteria two were identified as Gram-positive cocci i.e. Staphylococcus aureus and S. epidermidis, the remaining two were Gram-negative bacilli which were Escherichia coil and Pseudomonas aeruginosa. The fungus was identified as AspelEillus niger and the yeast like fungus Candida albican. The only protozoan found in some of the urine samples was Trichomonas vaginalis. These isolated and identified microorganisms were more susceptible to Norfloxacin, Velosef, Minocin, Nitrofurantoin, Malidixic acid and Metronidazole whereas antibiotics Penbritin and Cefaloridine were least effective against these microorganisms.

Journal Article↗
PubMed2005

[Study on benzene degraded by soil microorganism].

The experiments were made in laboratory to analyze the characteristics and principle of benzene's biodegradation using the microorganism (G-, Flavobacterium) taken from Daqing oil fields. Results show that the maximal concentration of benzene, which microorganisms could endure is between 8.8 mg x L(-1) and 17.6 mg x L(-1); microorganisms were inhibited as benzene's concentration was beyond 17.6 mg x L(-1). Trends of benzene's concentration in and out of microorganism's cell are almost same; the biodegradation could be achieved efficiently as the pH range of 6.5 - 7.0 and benzene initial concentration range of 7.04 - 13.2 mg x L(-1). Change of - lgP (P is the distributive ratio of benzene in membrane and water) could be illustrated the trends of toxicity and degradation of benzene in and out of microorganism's cell; the biodegradation rate varied simultaneously with the change of P as initial concentration of benzene was beyond 8.8 mg x L(-1).

Bacteria↗
PubMed1991

[The effect of selected antibiotics on microorganisms contaminating boar ejaculate].

The occurrence of microorganisms, including their total counts in boar native ejaculates, was investigated in two stages; the objective of this investigation also was to determine contamination after the sperms were treated with diluents containing the antibiotics ampicillin, gentamycin, apramycin, cefoxitin, or antibiotic combinations penicillin + streptomycin, ampicillin + cefoxitin, gentamycin + cefoxitin and ampicillin + gentamycin. The representation of bacterial species and total counts of microbes in 1 ml diluted sperm stored at a temperature of about 18 degrees C were determined in 24, 48 and 72 h after dilution. The microorganisms were cultivated from all native ejaculates. Proteus sp. (63.3%) and Pseudomonas aeruginosa (51.5% of the total number of examined samples) were the most frequent species. The number of contaminated diluted ejaculates ranged from 12.5 to 95.8% in 24 h after dilution, from 12.5 to 98.5% in 48 h and from 16.8 to 95.8% of the total number of examined ejaculates in 72 h. The occurrence of microorganisms correlated mostly with the efficiency spectrum of the antibiotics or their combinations. The average counts of microorganisms in 1 ml of native ejaculate made 2,363,000 in stage I and 1,472,108 in stage II. The highest average counts in 1 ml of diluted sperm were found in ejaculates containing cefoxitin and apramycin. Gentamycin was the most effective antibiotic used as a sole component (average counts of microorganisms CPM in 1 ml were 416 in 24 h, 955 in 48 h and 2260 in 72 h after dilution); ampicillin and gentamycin were the most efficient combination (14--20--21). This combination exerted very good effects also on Proteus sp. and Pseudomonas aeruginosa.

Animals↗
PubMedDate not supplied

[Effect of electromagnetic fields on movement of microorganisms].

Relationships between the motor activity and orientation of microorganisms and parameters of the electromagnetic field and of the microorganisms themselves were investigated. It has been shown that the type of microorganism and field amplitude produces the strongest influence on the behaviour of microorganisms in the fields. Theoretical relationships of the value of rotating moment and the field parameters, microorganism and environment were obtained. The results of the experiments well agree with the theory.

Cell Movement↗
PubMedDate not supplied

[Relationship between adsorption of microorganisms and the stage of their development].

Bond strength during adsorption of microorganisms depends on their growth stages, as was found by light optical and scanning electron microscopy. The strenth of adsorption often decreases as a culture growth on the surface of an adsorbent. Adsorption of microorganisms is an important ecological process. Under favourable conditions, microorganisms grow at a high rate when they are firmly bound to a solid surface. After abundant growth which deteriorates their microenvironment, microorganisms desorb and are dispersed. Such is a distribution of microorganisms growing on solid surfaces.

Adsorption↗
PubMed1986

[New principles and criteria in assessing pathogenic and opportunistic microorganisms].

Using the ecological and natural-science approaches, the authors have come to the conclusion that microorganisms, pathogenic for humans (animals), are their parasites for whom the disease of their biological host is the necessary condition of their existence as a biological species. And accordingly, microorganisms, opportunistic in humans (animals) are their parasites and commensals, as well as saprophytes, for whom the disease of their host is not the necessary condition of their existence in nature. The biological host is a symbion necessary for the existence of pathogenic and most opportunistic microorganisms, but for a pathogenic microorganism the disease of the host is the result of symbiotic relationships, while for an opportunistic microorganism the disease of the host is the consequence of disturbances in symbiotic relationships. Such view of pathogenicity is important for creating a scientifically grounded theory of the liquidation of human infectious diseases.

Animals↗
PubMed1983

Mechanisms by which indigenous microorganisms colonize gastrointestinal epithelial surfaces.

Indigenous microorganisms are known to associate with epithelial surfaces in the gastrointestinal tracts of birds and mammals of many species. In general, the mechanisms by which microorganisms associate with the epithelia are poorly understood. In some cases, in associating with epithelial surfaces, the microbial species involved undoubtedly colonize (i. e., multiply on) them. Some examples of such microorganisms are strains of certain Lactobacillus, and Candida (Torulopsis) species that associate with gastric surfaces, and strains of segmented, filamentous and of oxygen-intolerant anaerobic bacteria of numerous species that associate with intestinal surfaces in mice and rats. Several properties of the microbial cells involved may be important for them to be able to colonize epithelial habitats. Some such properties are a capacity for the cells to adhere to structures on the epithelium, or to be motile and able to move into the mucous gel present on most gastrointestinal surfaces. In addition, microorganisms that can colonize surface microhabitats on gastric or intestinal epithelia must be able to thrive in the environments and nutritional circumstances found in such habitats. In this respect, a capacity to multiply well in environments containing high concentrations of hydrogen ion is important for microbial cells to be able to colonize gastric surfaces, while a capacity enzymatically to digest mucinous glycoproteins and use the degradation products as carbon, energy and nitrogen sources may be important for microorganisms to be able to colonize most gastric or epithelial surfaces. These and related issues are examined in this paper.

Animals↗
PubMed1982

Gram-positive microorganisms in sepsis.

The significance of various microorganisms as pathogens in septicemia has been changing over the years. This has been amply demonstrated by several authors especially in the interesting survey from Boston by Maxwell Finland covering a 30 years' period from 1935-1965. Dramatic changes were noted among the Gram-positives and this seemed to coincide with the introduction of antibiotics. However, since that time a continuous variation of microflora isolated from patients with bacteremia has been reported, which indicates the significance of a through analysis of isolated pathogens presently and in the future. The difference in etiology in various age groups has been strengthened and microorganisms, which were seldom found ten years ago, are now of major clinical importance in septicemia. There is no simple explanation to this phenomenon but rather reflects a summary of influences including changes of the host-microorganism interaction induced by different treatment procedures, survival of patients with diseases with a negative effect on the infectious response, new and better microbiological diagnostic procedures, etc. The possibility that the increased frequency of e.g. group B streptococcal infections reflects a change in 'Status epidemicus' must also be born in mind. The clinical significance of changes in the etiology of septicemia is obvious since the microorganisms have different virulence factors, influencing in various ways upon the host. These microorganisms may also have a different or changing antibiotic sensitivity pattern. It should be added, however, that the changes in antibiotic sensitivity pattern is a multifacetted problem involving factors like types of patients in a hospital, treatment regime, antibiotic use.

Bacillus↗
PubMed1992

Coagulation autolysis in microorganisms and its relation to coagulase production.

The phenomenon of coagulation autolysis was observed in two model microorganisms, i.e., a bacterial culture and an imperfect fungus. It was characterized by impairment of the cell membranes, followed by condensation and dehydration of the cytoplasm and long-term preservation of the cells in the form of coagulated cytoplasm. In this respect, it was similar to coagulation necrosis of human tissues. The autolysis in the microorganisms was accompanied by increase of their coagulase activity, the substrate specificity of the enzyme rather broad. The coagulase activity of the microorganisms was detected during the culture period between the lag-phase and the exponential growth phase, i.e., the phase of their active growth. It served as a signal to induce biosynthesis of peptidohydrolase and cleavage of proteins. We believe that the phenomenon of coagulation autolysis in these microorganisms is rather typical and can be considered as an adaptative reaction, inducing a cascade of events from synthesis of coagulase to overproduction of peptidohydrolases with proteolytic activity.

Acremonium↗
PubMed1983

Conversion of inorganic lead into a highly-toxic organic derivative by marine microorganisms.

It has been reported that certain microorganisms isolated from lake sediments may transform inorganic lead compounds to organic derivatives, which are by at least one order of magnitude more toxic than the parent (inorganic) compounds. The purpose of this study was to investigate whether microorganisms isolated from a marine sediment could also produce such metabolites in an in vitro system simulating the marine ecosystem. The experimental setup included: 1) A sterile control system containing added inorganic lead (referred to as Pb2+); 2) a nonsterile control system without added Pb2+; 3) a nonsterile experimental system containing added Pb2+. The amount of added Pb2+ ranged from 5 to 1,000 ppm. Aliquots were taken at different intervals from the nonsterile systems and the surviving microorganisms were identified and counted. The main results were as follows: 1) The higher lead levels were toxic to all microorganisms. 2) Organic lead was only detected in the nonsterile experimental system, apparently due to microbial action, since none was found in the sterile systems. 3) Several bacteria exhibiting various degrees of tolerance for lead were isolated.

Aerobiosis↗
PubMed1994

Degradation of nitroaromatic compounds by microorganisms.

Nitroaromatic compounds are abundantly present in nature, but are in most cases highly toxic to living organisms. Several microorganisms, however, are capable of mineralizing or converting these compounds. Until now four pathways for the complete degradation of nitroaromatics have been described, which start with either the oxygenolytic or reductive removal of the nitro group from the aromatic ring or with this removal by means of replacement reactions. Besides these conversions many organisms are able to reduce nitroaromatics. The degradation of nitroaromatic compounds does not only occur in pure cultures but also in situ, for example in soil, water and sewage. However, several problems are associated with the application of microorganisms in the bioremediation of contaminated sites, as nitroaromatics or their conversion products may chemically interact with soil particles and cells. Besides the possibilities of applying microorganisms in the cleaning of sites contaminated with nitroaromatics, the use of microorganisms or enzymes in the biocatalytic production of industrially valuable products from nitroaromatics is also discussed.

Bacteria↗
PubMed1983

Colonization pattern of the digestive tract by potentially pathogenic microorganisms: colonization-controlling mechanisms and consequences for antibiotic treatment.

An outline is given of the various host-related and flora-related parts of the colonization resistance of the digestive tract. The host-related part of the colonization resistance has been found to be somewhat decreased by sublethal irradiation and leukemia (or chemotherapy), while treatment with antibiotics active against gram-positive flora may severely decrease the colonization resistance (depending on the antibiotic concentration established within the digestive tract during antibiotic therapy). The flora-related part of the colonization resistance, which controls colonization by potentially pathogenic microorganisms, differs greatly from one individual to the next. This observation appears to be important for the host-related part of the colonization resistance. Finally, it is concluded that in the clinical situation preference should be given to antibiotics which do not affect the part of the flora constituting colonization resistance for two reasons: 1) to limit the spread of (multi-) resistant potentially pathogenic microorganisms and 2) for infection prophylaxis in immunocompromised patients. In the latter situation, the potentially pathogenic microorganisms in the flora are selectively eliminated from the digestive tract, provided the antimicrobial drugs used for selective decontamination are active against the endogenous potentially pathogenic microorganisms and given in sufficient (oral) doses.

Animals↗
PubMed2001

[Effect of bioceramics on biological activity of microorganisms].

BACKGROUND AND OBJECTIVE: Biomaterials that come into contact with microorganisms in the middle ear or paranasal sinuses should be tested before clinical application. Thus, it is necessary to test the influence exerted on bacterial growth by biomaterials used as bone substitutes in head and neck surgery before implantation. PATIENTS AND METHODS: In this study, Bioverit, Al2O3 ceramic, and glass carbon were subjected to contamination with typical microorganisms in the middle ear and paranasal sinuses such as Staphylococcus aureus, Streptococcus pneumoniae and salivarius, Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis and Candida albicans. RESULTS: In the suspension test, all gram-negative species were inhibited, but gram-positive microorganisms and Candida albicans were not affected. The Al2O3 ceramic showed the largest inhibition effect while growth inhibition of glass carbon was low. Streptococcus pneumoniae and salivarius can use glass carbon as a nutrient. In contrast, Bioverit and Al2O3 ceramic could not improve the growth of all tested microorganisms. CONCLUSIONS: In conclusion, we think that Bioverit is suitable for implantation in bacterially contaminated regions of the head and neck, whereas glass carbon is unsuitable for this application in reconstructive surgery.

Aluminum Oxide↗
PubMed1999

Characterization of alpha-pinene-degrading microorganisms and application to a bench-scale biofiltration system for VOC degradation

A study was conducted to isolate and characterize monoterpene-degrading microorganisms and apply them to a biofiltration unit for use in degrading high levels of alpha-pinene. Soil from a monoterpene-contaminated site was used with enrichment culture techniques to recover a consortium of bacteria able to utilize alpha-pinene as the sole source of carbon and energy. The Biolog system was utilized to identify the bacteria as Pseudomonas fluorescens and Alcaligenes xylosoxidans. Aerobic growth and biodegradation studies confirmed that rapid growth and biodegradation were being achieved with alpha-pinene. Complete degradation of alpha-pinene was achieved in 36 h with a maximum rate of degradation of 3.9 mg/L/h. The microorganisms were placed in a biofiltration column and demonstrated good removal of alpha-pinene from an air stream at concentrations averaging 295 ppmv. A nitrogen test was performed and confirmed that the removal of alpha-pinene was due to biological activity. Given the ability of these microorganisms to utilize high levels of alpha-pinene, they will be used in a coupled treatment system using a physical/chemical adsorption/desorption unit coupled to a biofiltration column. Often, biofiltration studies are performed using much lower levels of analyte in the influent air stream. However, the ability of these microorganisms to utilize higher levels of compounds expands the capabilities for future coupled biofiltration systems. During future studies, high flow rates with low levels of analyte will be concentrated so that a higher analyte concentration and lower flow rate can be utilized with the biofilter.http://link.springer-ny. com/link/service/journals/00244/bibs/37n2p151.html

Journal Article↗