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PubMed2005

Screening of catalytically active microorganisms for the synthesis of 6-modified purine nucleosides.

Modified nucleosides can be prepared by microbial transglycosylation from cheaper nucleoside precursors using free or immobilised whole cells. An efficient screening method to find transglycosylation activity in microorganisms was developed for the synthesis of 6-modified purine nucleosides, such as 6-chloro-, 6-methoxy-, 6-iodo- and 6-mercaptopurine ribonucleoside. Out of 100 microorganisms screened, Bacillus stearothermophilus ATCC 12980 was the best for this purpose.

Bacteria↗

PubMed2006

Quantitative comparison of the signals of an electrochemical bioactivity sensor during the cultivation of different microorganisms.

The microbial activity of different microorganisms was determined by means of an electrochemical bioactivity sensor (BAS). The BAS is based on a biofuel cell and was used for analytical purposes. Online determination of microbial activity using the BAS demonstrated that when different microorganisms with different metabolic pathways were cultivated, a distinct activity signal was detectable with all organisms applied. Furthermore, the results permitted a quantitative comparison of the BAS signals. Among other findings it was shown that the quotient of the BAS signal and the utilized glucose varied from 0.16-29.08 mV g(-1), the quotient of the maximum BAS signal and the released energy of the reaction exhibited a lower variation of 0.07-0.19 mV kJ(-1). Furthermore it was demonstrated that the highest BAS signals could be measured during anaerobic E. coli fermentations, the reason being the formation of electroactive fermentation products, such as formic acid and H(2).

Bacteria, Aerobic↗

PubMed2006

Conversion of sucrose into isomaltulose by Enterobacter sp. FMB1, an isomaltulose-producing microorganism isolated from traditional Korean food.

Over 500 microorganisms isolated from Korean traditional foods, Maeju (source of soybean paste) and Nuruk (Korean koji), were screened to obtain an isomaltulose-producing microorganism. It was identified as Enterobacter sp. FMB-1 by 16S rRNA sequencing and the API 20E system. It had a greater than 90% conversion of sucrose (as 4 g/l) to isomaltulose in 2 days. Small amounts of trehalulose, glucose, and fructose were produced as byproducts, implying that this strain could be possibly employed in the production of isomaltulose in industry.

Enterobacter↗

PubMed2004

Role of inhibitors of proteolytic enzymes in plant defense against phytopathogenic microorganisms.

This review analyzes the literature on various mechanisms of proteolytic enzyme inhibitors involved in plant defense against attack by phytopathogenic microorganisms. The action of proteinase inhibitors from plants upon the enzymes from pathogenic microorganisms and viruses is reviewed. Considerable attention is given to the induction of proteinase inhibitors in plants in response to the invasion of pathogens. Some aspects of application of proteinase inhibitors in biotechnology for production of transgenic plants with enhanced resistance to diseases are discussed.

Adaptation, Biological↗

PubMed2005

Induction of secretory aspartyl proteinase of Candida albicans by HIV-1 but not HSV-2 or some other microorganisms associated with vaginal environment.

The most common type of candidiasis involves mucosal sites such as the oral cavity, the gastrointestinal tract and the vagina. Among many of virulence factors, the production of secretory aspartyl proteinase (Sap) by Candida albicans (C. albicans) has gained much attention, and factors leading to Sap induction are thus under intense study. The aim of this study was to examine whether some microorganisms such as Lactobacillus, Gardnerella vaginalis (G. vaginalis), human immunodeficiency virus type-1 (HIV-1) and human herpes simplex virus type-2 (HSV-2) had any Sap inducing effect on C. albicans. Here we showed that among the microorganisms tested in vitro only HIV-1 induced Sap production from C. albicans.

Candida albicans↗

PubMed2005

Dutch guideline for preventing nosocomial transmission of highly resistant microorganisms (HRMO).

Hospitals are faced with the increasingly rapid emergence and dissemination of antimicrobial-resistant microorganisms. US and European guidelines on the prevention of antimicrobial resistance in hospitals were, until recently, mainly directed at methicillin-resistant Staphylococcus aureus (MRSA). In 2004, the Dutch Working Party on Infection Prevention issued a guideline on the prevention of nosocomial transmission of highly resistant microorganisms (HRMO), in order to fulfill the growing need for additional guidance on the control of other pathogens with acquired resistance and the potential to spread within hospitals (such as glycopeptide-resistant Enterococcus faecium, penicillin-resistant Streptococcus pneumoniae, extendedspectrum beta-lactamase producing Enterobacteriaceae, and other (multi)drug-resistant gram-negatives). In addition to providing criteria for defining HRMO, the Dutch guideline provides recommendations on isolation of patients, active surveillance, and contact tracing. The guideline will enable the comparison of HRMO rates between hospitals, and may be used to evaluate the efficacy of programs to control antibiotic use and/or nosocomial transmission of resistant pathogens. The eventual success of nationwide implementation of this guideline remains to be established in the coming years.

Cross Infection↗

PubMed1993

Sexual intercourse during pregnancy and preterm delivery: effects of vaginal microorganisms. The Vaginal Infections and Prematurity Study Group.

OBJECTIVE: Our aim was to investigate the influence of vaginal colonization with specific microorganisms on the relationship between sexual intercourse during pregnancy and preterm delivery. STUDY DESIGN: As part of a multicenter, prospective study interviews and physical examinations were conducted with and genital cultures were obtained from women seeking prenatal care from 23 to 26 weeks' gestation. At 31 to 36 weeks interviews were conducted with a randomly selected sample of these patients. RESULTS: Frequent intercourse (defined a priori as once per week or more) at 23 to 26 weeks was associated with a significantly reduced risk of subsequent preterm delivery in women without Trichomonas vaginalis, Mycoplasma hominis, or bacterial vaginosis, possibly because of the relative health and lack of complications in the pregnancies of those women engaging in sexual intercourse. Frequent intercourse was not significantly associated with preterm delivery in women with T. vaginalis, M. hominis, or bacterial vaginosis. Neither T. vaginalis, M. hominis, nor bacterial vaginosis was associated with preterm delivery among women with infrequent intercourse at 23 to 26 weeks. However, T. vaginalis and M. hominis were risk factors for preterm delivery among those with frequent intercourse. CONCLUSIONS: Frequent sexual intercourse by itself is not associated with an increased risk of preterm birth. However, women who are colonized with specific microorganisms and who engage in frequent intercourse are at increased risk of preterm delivery.

Adolescent↗

PubMed1975

The survival and growth of microorganisms in mascara during use.

Over 150 mascaras representing eight popular brands were examined for their susceptibility to microbial contamination during their use by study group members. Additional mascaras from patients with symptoms and clinical findings of long-term blepharitis also were investigated. Early in the study, two brands without preservatives supported reproducing populations of microorganisms, including potential eye pathogens. These products, as currently manufactured, were recalcitrant to microbial attack. Microbes associated with the facial skin and fingers of the study group users were typically isolated from mascaras after use. Initial microorganisms isolated from mascaras were usually transients. Establishment of reproducing populations within the cosmetics appeared related to the number of uses, personal habits of the user, and the formulation of the product. Four patients with staphylococcal blepharitis and cosmetics heavily laden with Staphylococcus epidermidis showed marked clinical improvement when they stopped using the contaminated cosmetics. The application of used eye area makeup prior to and following ocular surgery should be avoided.

Bacillus↗

PubMed1988

M13 phage DNA as a universal marker for DNA fingerprinting of animals, plants and microorganisms.

Hypervariable polymorphic patterns were detected with M13 phage DNA as a probe in genomic DNA of organisms belonging to different taxonomic groups including animals (vertebrates and invertebrates), plants and microorganisms. Individual-specific restriction pattern analysis (DNA fingerprinting) with this probe proved to be useful for individual identification, analysis of somatic stability and paternity testing in man. The nuclear type of inheritance indicates that the hypervariable DNA regions in question are located in the chromosomes, not in the mitochondrial DNA. The data obtained also demonstrate a potential range of M13 DNA applications as a probe for DNA fingerprinting of animals, plants and microorganisms, particularly for the determination of inbred lines, identification of bacterial strains and establishing stock, variety and strain distinctions.

Animals↗

PubMed1979

A novel technique for detecting IgA coated potentially pathogenic microorganisms in the human intestine.

This paper describes a novel method for detecting immunoglobulin A (IgA) coated potentially pathogenic microorganisms (PPMs) in the human intestine. Essentially, the technique consists of 2 phases: one in which IgA coated bacteria are detected by immunofluorescence and a second in which these bacteria are subcultured in situ and subsequently identified. In this way transient bacteria are differentiated from resident bacteria. These results show that the resident bacteria are coated with IgA. Resident microorganisms are always highly concentrated in the digestive tract. These results strengthen the hypothesis that only the high antigen concentrations achieved by a large number of resident bacteria are capable of IgA induction.

Antibodies, Bacterial↗

PubMed1982

A simple rapid method for quantifying microorganisms by their metabolic activity when bound to a specific adsorbent.

A simple rapid assay for microorganisms is described. An adsorbent capable of binding microbial cells is deposited in a disposable plastic syringe. A sample to be analyzed is drawn into the syringe and the number of attached microorganisms is calculated from their ability to produce metabolites. The smallest number of yeast cells in a given sample was 50,000. Each analysis takes 2.5 h.

Concanavalin A↗

PubMed1986

Comparison of methods to test chemicals for side effects on soil microorganisms.

The effects of the test chemicals pentachlorophenol (PCP) and HgCl2 on the bioactivity of microorganisms in three different soils were studied in low and high concentrations (2 and 20 ppm). Bioactivity was measured in long-term experiments (18 weeks) by a threefold application of chemicals to soils of varying moisture content. The selected tests were measurements of ATP, of heat output under aerobic and anaerobic conditions and after amendment with glucose, of soil respiration after the addition of glucose, and Fe(III) reduction. The suitability of each test depends on soil microorganisms, on environmental conditions, and on soil properties. The effects caused by the chemicals were as follows. For the low concentration, stimulation or inhibition were mostly repaired within the observation period. The high concentration mostly induced inhibitions which increased or decreased as a consequence of the repeated application of the chemicals. The effects of chemicals were strongly modified by the soil types: in a soil with high organic matter content, differences to the control were lower than in soils with lower organic matter content. These experiments also indicate that measurement of only one physiological parameter is not sufficient to characterize chemicals ecotoxicologically.

Carbon Dioxide↗

PubMed1994

Chemosensory transduction in eukaryotic microorganisms: trends for neuroscience?

It might appear curious to read about yeast, slime molds and protozoa in a journal dedicated to neuroscience. However, despite their distinct lack of synapses, eukaryotic microorganisms hold a wealth of information relevant to the signal-transduction pathways that underly activity in neuronal receptor cells, particularly those subserving the chemical senses. Microorganisms are sensitive to chemical stimuli from their environment and thus have similarities to receptor neurons of the olfactory system and the taste bud. Here, we introduce receptors, second messengers and effectors responsible for chemosensory signal transduction in yeast mating, sea-urchin spermatozoan chemotaxis, slime-mold aggregation and development, and ciliate chemoresponses.

Animals↗

PubMed1991

Complement evasion strategies of microorganisms.

The success of microorganisms as human pathogens stems partly from their ability to evade recognition and/or avoid destruction by complement and other natural and acquired defense mechanisms. Here, Neil Cooper reviews the various mechanisms that pathogens have evolved to evade the destructive actions of the complement system, with particular emphasis on the many remarkable examples of the duplication of complement-like structural and functional epitopes by microorganisms. Such mimicry not only enables the pathogens to avoid destruction by complement-mediated mechanisms but also, in a number of instances, facilitates infection.

Bacterial Proteins↗

PubMed1988

Proposed guidelines for maximum acceptable air-borne microorganism levels in dairy processing and packaging plants.

From the total number of air-borne microorganisms present per m3 of air, 1.5% were found to contaminate a dairy product while being packed into a container with an opening of 100 cm2 if it was exposed for 60 s. This value was used to compile a proposed guideline of maximum acceptable number of air-borne microorganisms per m3 which, if complied with, could ensure that no significant air-borne contamination of the product being packaged would take place.

Air Microbiology↗

PubMed1990

Survival of pathogenic microorganisms in an egg-nog-like product containing 7% ethanol.

A liquor consisting of whole egg, saccharose (25% w/v) and ethanol (7.0% w/v) was artificially contaminated with Salmonella enteritidis, S. typhimurium, Staphylococcus aureus (three different strains), Bacillus cereus and Listeria monocytogenes. After 3 weeks of incubation at 22 degrees C the numbers of Salmonella, S. aureus and L. monocytogenes decreased more than 3 log10 units. Under such conditions, however, the total number of microorganisms increased 3 log10 units. At 4 degrees C the decrease of pathogenic microorganisms was much slower and a decrease of 3 log10 units was observed only after 7 weeks of incubation. Egg-nog, without ethanol, incubated at 22 degrees C allowed growth of Salmonella and S. aureus, while the numbers of B. cereus spores remained unchanged. Vegetative cells of B. cereus as well as L. monocytogenes decreased in numbers. However, after prolonged incubation the numbers of L. monocytogenes increased significantly.

Alcoholic Beverages↗

PubMed1993

Eicosapentaenoic acid (EPA) production from microorganisms: a review.

Eicosapentaenoic acid EPA has been shown to be of major importance in the prevention and treatment of a range of human diseases and disorders. At present fish oil is the only source of EPA that is considered unattractive because it contains substantial amounts of undesirable fatty acids and cholesterol. Consequently, alternative sources of EPA are being sought, especially from algae and from fungi of the order Mucorales. This review presents information about EPA producing microorganisms, data on the production and recovery aspects along with the potential of microorganisms as commercial sources of EPA.

Bacteria↗

PubMed1992

The housefly (Musca domestica) as a carrier of pathogenic microorganisms in a hospital environment.

Houseflies have long been regarded as potential carriers of microorganisms. Since pathogenic microorganisms are widespread in the hospital environment, there is abundant opportunity for flies to become contaminated and, in turn, to contaminate the patient environment. In the present study, an attempt was made to isolate and identify pathogenic bacteria, fungi and parasites from the housefly Musca domestica collected in the surgical ward of the All India Institute of Medical Sciences Hospital and also in a remote residential area located 5 km from the hospital. A total of 113 flies were collected: 65 from a surgical ward (test) and 48 from a residential area for comparison. Ten genera of bacteria were isolated from the test group of flies compared with nine from the control group. In primary isolations, it was observed that the load of bacteria carried by the test group of flies was significantly more (P less than 0.001) than for the control flies. Pseudomonas aeruginosa, Enterococcus faecalis and viridans streptococci were isolated only from the test flies. The isolation rate of Staphylococcus aureus was significantly higher (P less than 0.001) in test houseflies than in the control houseflies. There was no significant difference in isolation of parasitic ova and cysts from test and control houseflies. Candida spp. were isolated in almost equal numbers from both groups of houseflies, yet none of these was Candida albicans. Houseflies therefore may act as vectors of potentially pathogenic bacteria in a hospital environment.

Animals↗