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At least 145 records · Page 8Linked to original sources

PubMed1989

[Studies on harmful microbes in recirculating cooling water system of oil refinery].

The microbiol counts, type, distribution as well as interrelation between microbial counts and biofouling of the main harmful microbes including slimeforming heterotrophic bacteria, sulfate reducing bacteria, iron bacteria and fungi has been studies in 16 oil refineries of China. The control guideline of the harmful microbes for recirculating cooling water system of refinery were suggested, that is slime-forming bacteria less than 10(5)/ml, sulfate reducing bacteria less than 10(2)/ml. iron bacteria less than 10(3)/ml, fungi less than 10/ml. The appearing rate of the predominant strains from cooling water system of various refineries were calculated and identified and the composition of the main harmful representative microbes in cooling water system were determined.

Cold Temperature↗

PubMed1983

Factors influencing microbe insecticide interactions.

Microorganisms are present in almost all environmental components where insecticides are used and they will, therefore, encounter with the latter. In simplest terms, such interactions can be considered as (1) the action of microbes on insecticides and (2) the action of insecticides on microbes. These interactions can not be as clearly understood without understanding the influence of environmental factors that control the fate and activity of microorganisms. The proposed review will focus on two areas. The first is related to the test methods used to study the microbial insecticide interaction, the second area is concerned with the influence of environmental factors on the action of microbes and vice versa.

Bacteria↗

PubMed1982

Allergic syndrome in chronic cholecystitis and colitis, the efficiency of specific hyposensitivity with microbic allergen.

In more than 1000 patients with noncalculous cholecystitis, chronic colitis (nonulcerative, nonspecific ulcerative, Crohn's disease of the bowel) and with dyskinesia of intestine the participation of allergic components was investigated in the development and chronic duration of the diseases. More often was observed the sensibilization to bacteria of conditionally pathogenetic microflora (E. coli, staphylococcus, streptococcus, proteus) that was confirmed by positive skin tests, sensibilization of lymphocytes to microbic allergens, increase of the titer of microbic antibodies in blood. The sensibilization to tissue proteins and subcellular fractions (nucleus, mitochondrias, microsomes) was seldom observed. Autoimmune disorders appeared in patients with nonspecific ulcerative colitis by ascending doses of bacterial allergens of E. coli, proteus, staphylococcus, streptococcus. By means of the study of direct and remote results of specific immunotherapy there was established the dynamic of clinical and laboratory-instrumental indices of the patients state, and of immunologic tests, reflecting the nonspecific factors of defense, microbic and tissue allergy.

Antigens, Bacterial↗

PubMed1980

[Effect of imidazole derivatives on various numbers of microbes to determine microbial sensitivity].

Imidazole derivatives with antifungal activity were investigated in their effects on concentrated and diluted suspensions of Saccharomyces cerevisiae, Candida albicans, and Staphylococcus aureus haemolyticus. Against Candida albicans, activity of the imidazol derivatives was higher in diluted suspensions than in concentrated suspensions: this fact proves the presence of a microbe-count sensitivity. Against Saccharomyces cerevisiae and Staphylococcus aureus haemolyticus, no microbe-count sensitivity of clotrimazole, econazole nitrate, ketoconazole, or N-148/76 could be detected by Warburg assay on resting microbes.

Candida albicans↗

PubMed1994

[Improvement of a method for detecting of strains of the plague microbe using polymerase chain reaction].

Three pairs of oligonucleotide primers, complementary to nucleotide sequences of Yersinia pestis plasmids (pPst, 9.5 kb; pCad, 70 kb; pFra, 95 kb), were used in polymerase chain reaction for high-sensitive specific detection of plague pathogen. Primer pairs P1,P2,C1,C2, and F1,F2 were used to amplify fragments of pla gene (plasmid pPst), yop1 gene (plasmid pCad of plague microbe), and caf1 gene (plasmid pFra), respectively. The method developed enables specific detection of strains from all natural loci in Russia and contiguous states as well as strains of oceanic origin. Sensitivity of method is 50-100 CFU/ml. Primer sequences enable to amplify gene fragments, located in three own plasmides of plague microbe, in the same reaction mixture. The method offers identification of plague microbe and determination of its virulence and epidemic significance.

Base Sequence↗

PubMed1998

[Characteristics of etiotropic therapy of plaque infection induced by atypical strains of F1- phenotype plaque microbe].

The efficacy of various group antibacterial drugs: aminoglycosides, quinolones, 3rd generation cephalosporins, doxycycline, rifampicin, ampicillin and azthreonam was estimated in the treatment of experimental plague of albino mice induced by antigen complete and atypical strains of the F1- phenotype plague microbe. The in vitro experiments showed that all the strains of the plague microbe irrespective of the phenotype (F1+ or F1-) were highly susceptible to the drugs. The animal experiments demonstrated that aminoglycosides (streptomycin, kanamycin, tobramycin, gentamicin and amikacin) and cephalosporins (ceftriaxone and ceftazidim) were highly efficient in the prophylaxis and treatment of plague due to F1+ and F1- strains. In experimental plague due to F1- phenotype plague microbe the prophylactic effects of cefotaxime, cefoperazone, sulbactam/ampicillin, azthreonam, ciprofloxacin and rifampicin were lower. However, increase of the daily doses of the drugs and prolongation of the treatment course up to 7 days made it possible to increase the protective effects up to 80-100 per cent. Doxycycline and ampicillin were not sufficiently efficient even when used for 10 days in the prophylaxis of plague due to F1- strains.

Aminoglycosides↗

PubMed2026

Identification of a novel human gut microbes and microbial metabolites related genes signature for prognostic implication in head and neck squamous carcinomas.

BACKGROUND: The gut microbiota acts as a critical driver influencing the pathogenesis, therapeutic response, and clinical outcomes across various cancer types. This study aimed to investigate the prognostic value of human gut microbes and microbial metabolites related genes (HGMMMRGs) in head and neck squamous cell carcinoma (HNSCC). METHODS: We constructed a prognostic risk model comprising 19 core HGMMMRGs using LASSO penalized regression and a multivariate Cox proportional hazards model. The predictive performance of the model was evaluated through Kaplan-Meier analysis, receiver operating characteristic (ROC) curves, nomograms, and concordance index. In addition, functional enrichment analysis was performed on the differentially expressed risk genes. Furthermore, the relationship between the immune microenvironment of HNSCC and the risk diagnostic model was examined. Western blot analysis was used to assess the expression levels of IL10 in both HNSCC tissues and adjacent normal tissues. Finally, the correlation between IL10 and the gut microbiota was explored. RESULTS: This study developed a risk score model integrating 19 HGMMMRG genes, which can serve as a tool to guide prognosis and immune microenvironment assessment in HNSCC patients. Survival analysis showed that patients in the high-risk group had significantly worse outcomes (P < 0.05). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed significant enrichment of differentially expressed genes (DRLs) and immune-related pathways. Western blot analysis further confirmed that IL10 was highly expressed in HNSCC, and the abundance of Faecalibacterium prausnitzii and Enterococcus durans colonies was correlated with IL10 expression. CONCLUSION: We developed a prognostic model for HGMMMRGs that can be effectively used to predict OS in patients with HNSCC. Second, Faecalibacterium prausnitzii and Enterococcus durans can influence the prognosis of patients with HNSCC by mediating the expression IL10 and thereby affecting the prognosis of HNSCC patients. Thus, human gut microbes and microbial metabolite-related genes may be another promising strategy for the treatment of patients with HNSCC.

HNSCC↗

PubMed1994

Human HE2 (microB) and microA motifs show the same function as whole IgH intronic enhancer in transgenic mice.

In the murine IgH gene intronic enhancer (ENHiH), two major functional domains were reported. One is the E4/octomer region and another includes the microA and microB motifs. In the human ENHiH, it was reported that the HE2, which corresponds to the murine microB, and E6 motifs play an important role in an enhancer activity and a tissue-specificity at cellular level. Here we examined the in vivo function of the E6, microA and HE2 motifs within the human ENHiH by using the transgenic mice technique. The microA and HE2 motifs together revealed almost the same enhancer function as the whole human ENHiH, but the E6 motif had lesser enhancer activity and tissue-specificity.

Animals↗

PubMed1998

Difference in microbes contaminating pancreatic necrosis in biliary and alcoholic pancreatitis.

CONCLUSION: There are differences in the microbiology of infected pancreatic necrosis in alcoholic and biliary pancreatitis. One possible explanation may be different routes of contamination. BACKGROUND: Infection is a severe complication in acute pancreatitis. Bacteria are found in 40-70% of all patients suffering from necrotizing pancreatitis. We investigated whether there were any differences in microbes isolated from pancreatic necrosis in biliary and alcoholic pancreatitis. METHODS: Microbiological tests were conducted on necrosis taken at the operation for pancreatitis with the etiology of (group A) alcoholic pancreatitis (n = 47) and (group B) biliary pancreatitis (n = 23). Patients with simultaneous cholecystitis were excluded. The time from the first symptoms to the operation or the extent of necrosis did not differ between the groups. RESULTS: Microbes were isolated more often in the cultures from group B than group A (17/23 = 74% vs 15/47 = 32%, p = 0.001). The most common were Gram-positive bacteria in group A and Gram-negative bacteria in group B. From the first week, from the onset of symptoms to the operation. Gram-negative bacteria were isolated significantly more often in the cultures from group B patients than from group A patients (8/10 = 80% vs 1/5 = 20%, p = 0.04). In multivariate analysis, we found that biliary pancreatitis was an independent risk factor (adds ratio 5.5, 95% confidence interval [CI] 0.59-52.10) of contamination of necrosis with Gram-negative bacteria.

Adult↗

PubMed2006

Three-dimensional microorganization of the soil-root-microbe system.

Soils contain the greatest reservoir of biodiversity on Earth, and the functionality of the soil ecosystem sustains the rest of the terrestrial biosphere. This functionality results from complex interactions between biological and physical processes that are strongly modulated by the soil physical structure. Using a novel combination of biochemical and biophysical indicators and synchrotron microtomography, we have discovered that soil microbes and plant roots microengineer their habitats by changing the porosity and clustering properties (i.e., spatial correlation) of the soil pores. Our results indicate that biota act to significantly alter their habitat toward a more porous, ordered, and aggregated structure that has important consequences for functional properties, including transport processes. These observations support the hypothesis that the soil-plant-microbe complex is self-organized.

Bacterial Physiological Phenomena↗

PubMed2001

Influences of incubation temperature and various saccharides on the production of organic acids and gases by gut microbes of rainbow trout Oncorhynchus mykiss in a micro-scale batch culture.

We studied the influence of incubation temperature and additional saccharides on the metabolism of hindgut microbes of the rainbow trout Oncorhynchus mykiss in a 50 microl-scale batch culture system. Intestinal contents of rainbow trout reared at 15 degrees C were incubated with glucose, lactosucrose, sodium alginate or colloidal chitin (each 10 g/l) at 15 degrees C or 25 degrees C for 12 h. Levels of organic acids at 0 h and 12 h of incubation were quantified with HPLC. We also monitored gas release from these cultures during incubation. The main product was iso-butyric acid, except for the cultures with colloidal chitin where no net production of organic acids was observed. We detected higher levels of iso-butyric acid in cultures with lactosucrose than in the other cultures. Net production of this acid was less in cultures with colloidal chitin than in blank cultures. The volume of released gas was larger when incubated at 25 degrees C than at 15 degrees C. Cultures with colloidal chitin released more gas than blank cultures when they were incubated at 15 degrees C. Cultures with sodium alginate released less gas than blank cultures irrespective of incubation temperature. These results indicate that the hindgut microbes of this carnivorous fish mainly produce branched-chain fatty acids, very likely by microbial digestion of nitrogenous materials rather than saccharides. However, additional saccharides affected production of branched-chain fatty acids. The influence of incubation temperature in the present study also suggested that the environmental temperature of host fish should affect microbial digestion in the fish gut.

Acids↗

PubMed2002

Plant-microbe interactions and the new biotechnological methods of plant disease control.

Plants constitute an excellent ecosystem for microorganisms. The environmental conditions offered differ considerably between the highly variable aerial plant part and the more stable root system. Microbes interact with plant tissues and cells with different degrees of dependence. The most interesting from the microbial ecology point of view, however, are specific interactions developed by plant-beneficial (either non-symbiotic or symbiotic) and pathogenic microorganisms. Plants, like humans and other animals, also become sick, but they have evolved a sophisticated defense response against microbes, based on a combination of constitutive and inducible responses which can be localized or spread throughout plant organs and tissues. The response is mediated by several messenger molecules that activate pathogen-responsive genes coding for enzymes or antimicrobial compounds, and produces less sophisticated and specific compounds than immunoglobulins in animals. However, the response specifically detects intracellularly a type of protein of the pathogen based on a gene-for-gene interaction recognition system, triggering a biochemical attack and programmed cell death. Several implications for the management of plant diseases are derived from knowledge of the basis of the specificity of plant-bacteria interactions. New biotechnological products are currently being developed based on stimulation of the plant defense response, and on the use of plant-beneficial bacteria for biological control of plant diseases (biopesticides) and for plant growth promotion (biofertilizers).

Bacteria↗

PubMed2006

New drugs from marine microbes: the tide is turning.

This is a mini-review demonstrating that investigation of the genomics of marine microbes from all three domains has the potential to revolutionize the search for secondary metabolites originally thought to be the product of marine invertebrates. The basis for the review was a symposium at the 2005 Annual Meeting of the SIM covering some aspects of the potential for marine microbes to be the primary producers of such metabolites. The work reported at that symposium has been integrated into a fuller discussion of current published literature on the subject with examples drawn from bacteria, cyanophytes and fungi.

Actinobacteria↗

PubMed2006

Differential biohydrogenation and isomerization of [U-(13)C]oleic and [1-(13)C]oleic acids by mixed ruminal microbes.

The additional mass associated with 13C in metabolic tracers may interfere with their metabolism. The comparative isomerization and biohydrogenation of oleic, [1-(13)C]oleic, and [U-13C]oleic acids by mixed ruminal microbes was used to evaluate this effect. The percent of stearic, cis-14 and -15, and trans-9 to -16 18:1 originating from oleic acid was decreased for [U-(13)C]oleic acid compared with [1-(13)C]oleic acid. Conversely, microbial utilization of [U-(13)C]oleic acid resulted in more of the 13C label in cis-9 18:1 compared with [1-(13)C]oleic acid (53.7 vs. 40.1%). The isomerization and biohydrogenation of oleic acid by ruminal microbes is affected by the mass of the labeled tracer.

Analysis of Variance↗

PubMed1986

Animal glycolipids as attachment sites for microbes.

The abundance of carbohydrate at the animal cell surface may explain why microbes have selected primarily carbohydrates as essential attachment sites for colonization or infection. Of the various surface glycoconjugates of interest, primary attention has been given to glycolipids, due in part to an efficient binding assay based on a thin-layer chromatogram with separated glycolipids. In this way the general character of carbohydrate recognition by microbes is being mapped. Mainly two examples are briefly described to illustrate some generalizations: lactosylceramide-recognition by several bacteria, and Gal alpha l----4Gal-binding by Escherichia coli and the Shiga toxin. The unique recognition of internally placed sequences, the often low-affinity binding, and the preference of certain sequences before others are interpreted to be of decisive biological value. The binding to internal parts makes it technically possible to approximate the binding epitope on a receptor glycolipid. For this the binding preferences to glycolipids carrying the binding site in different saccharide environments (isoreceptors) are compared with the computer-calculated preferred conformations (definition of steric hindrances to epitope access). Several binding epitopes dissected with this approach have a common surface character: a nonpolar area of ring hydrogens over one or two sugars, surrounded by polar oxygens or amide. This is in agreement with the recent Lemieux concept for antibody-carbohydrate interaction. This information facilitates a rational synthesis of receptor analogues for potential applications. An outline is finally given of an improved general approach for receptor analysis.

Animals↗

PubMed1985

Heavy metal toxicity to microbe-mediated ecologic processes: a review and potential application to regulatory policies.

Microorganisms are sensitive to heavy metal pollution as are other components of the biota. However, most studies on the interactions between microbes and heavy metals have been conducted in synthetic media or in altered (e.g., sterilized) environmental samples and usually have used only single species. Few studies have evaluated the effects of heavy metals on the activities of natural heterogeneous microbial populations, both autotrophic and heterotrophic, in terrestrial and aquatic environments. These latter studies have shown that heavy metals inhibit primary productivity, nitrogen fixation, the mineralization of carbon, nitrogen, sulfur, and phosphorus, litter decomposition, and enzyme synthesis and activity in soils, sediments, and surface waters. The potential adverse effects of heavy metals on such microbe-mediated ecologic processes need to be incorporated into the methodologies used by regulatory agencies, such as the U.S. Environmental Protection Agency, to prepare environmental risk assessments which, in turn, are used to formulate environmental criteria, such as the Water Quality Criteria, and to evaluate the safety to the environment of exposure to "new chemical substances," as mandated by the U.S. Toxic Substances Control Act of 1976. To provide appropriate data that can be assimilated into regulatory policy, it is essential that microbial ecotoxicity tests be standardized, are neither costly nor difficult to train personnel to conduct, and produce data that can be quantitated.

Bacteria↗

PubMed2004

Anaerobic transformation of 2,4,6-TNT by bovine ruminal microbes.

Degradation of TNT by bovine rumen fluid, a novel source of anaerobic microbes, was investigated. Whole rumen fluid contents were spiked with TNT and incubated for a 24h time period. Supernatant samples taken at 0, 1, 2, 4, and 24h were analyzed by reverse-phase HPLC with diode array detection. Within 1h, TNT was not detectable and reduction products of TNT including 2-hydroxyl-amino-4,6-dinitrotoluene, 4-hydroxylamino-2,6-dinitrotoluene, and 4-amino-2,6-dinitrotoluene were present with smaller amounts of diamino-nitrotoluenes. Within 2h, only the diamino and dihydroxyamino-nitrotoluene products remained. After 4h, 2,4-diamino-6-nitrotoluene and 2,4-dihydroxyamino-6-nitrotoluene were the only known molecular species left. At 24h known UV absorbing metabolites were no longer detected, suggesting further transformation such as complete reduction to triaminotoluene or destruction of the aromatic ring of TNT may have occurred. TNT was not transformed at 24h in autoclaved and buffered controls. This study presents the first direct evidence of biodegradation of TNT by ruminal microbes.

Anaerobiosis↗

PubMed2003

Do microbes influence the pathogenesis of allergic diseases? Building the case for Toll-like receptor ligands.

The prevalence and severity of allergic diseases and other diseases of immune dysregulation are increasing in industrialized countries. One explanation for these trends is that decreased exposure to microbes, due to modern public health practices, has resulted in the loss of a main source of immune provocation, and a consequent increase in pathogenic immune responses and their associated diseases. It is now clear that molecular interactions between immunocytes and microbes are mediated largely by Toll-like receptors (TLRs) on host cells and a diversity of ligands produced by viruses, bacteria and fungi. Physiological exposures to TLR ligands are also likely to have an important yet complex role in host immune homeostasis and predisposition towards atopy.

Adaptor Proteins, Signal Transducing↗