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PubMed1984

[Quantitative monitoring of microorganisms in incoming air of air conditioning systems in hospitals].

In eight hospitals the quantity of microorganisms in the supply air of air conditioning systems was determined. A Reuter-Centrifugal-Sampler (by Biotest, Frankfurt) sampled 160 litres of air in four minutes and blew the particles with microorganisms on a culture medium (GKA-medium, by Biotest, Frankfurt). The Agar was breeded for 48 hours at 37 degrees C. The colonic-forming-units were counted and transformed to a volume of a cubic meter (CFU/m3). - In other publications you can find determinations of microorganisms in the supply air for operating theatres up to 15 CFU/m3. We found up to 40 CFU/m3 in the supply air after three step filtration (with an high efficiency filter) and 20-85 CFU/m3 after two step filtration. - The recommendations of other authors and some directives say that in the supply air up to 10 CFU/m3 are acceptable. According to our experiences the supply air should not contain more than 10 CFU/m3 after a 3-step-filtration and not more than 50 CFU/m3 after a 2-step-filtration. Otherwise the function of the air conditioning system should be controlled and the maintenance, too. - We think that according to the different requirements in hygiene a supply air with less than 10 CFU/m3 in the mean allows an unlimited use of the air conditioned room, while mean values up to 50 CFU/m3 are acceptable for normal operating rooms and other rooms, except for operating rooms with special hygienic requirements as for example for transplantation, arthroplasty, heart-operations (corresponds to II. and III. classification of rooms, DIN 1946/4). - Values up to 150 CFU/m3 are acceptable for rooms with normal hygienic requirements for supply air (III. classification of rooms, DIN 1946/4) and for labour-, intensive-care, newborn- and infant rooms.

Air Conditioning↗

PubMedDate not supplied

[Regulation of metabolism in microorganisms with CO2 fixation].

The paper deals with a review of the data available in literature on the regulation of the metabolic processes in microorganisms with CO2 fixation. The main function of CO2 is traced as exemplified by different types of microorganism nutrition. The carboxylation reactions in their main forms are observed in all heterotrophic microorganisms. The experimental data relative to the heterotrophic fixation of CO2 in yeast assimilating oil carbohydrates are presented as an example. The degree of CO2 fixation under these conditions may reach 30%. Carbon of CO2 is utilized for the biomass biosynthesis.

Carbohydrate Metabolism↗

PubMed1982

[Lipolytic microorganisms in liver products].

Products from liver were studied for the content of lipolytic microorganisms during production and storage. Lipolytic microorganisms were found in all samples of the products. Their occurrence ranged from 10(4) to 10(7) organisms per g. In finished products and in products stored at a refrigerator temperature their numbers were much lower (10-10(4) per g). Some samples were free from them. The isolated colonies of lipolytic microorganisms were included in the genera Bacillus, Staphylococcus, Pseudomonas, Achromobacter. The acidity number was in correlation with the number of lipolytes in products before thermal processing and in stored products.

Bacteria↗

PubMed1980

[Psychrotrophic microorganisms in raw and pasteurized milk].

The studied were carried out in 360 samples of unboiled milk and 1080 samples of pasteurized milk taken from three processing and distributing dairies having a different capacity and equipment. It was proved that the content of psychrotrophic microorganisms in unboiled milk from the three dairies varied from 120000 up to 200000 in 1 cm3 and was in close connection with the seasons of the year. The conditions applied for pasteurization in the three dairies killed (with the exception of those forming spores) nearly all psychrotrophic bacteria. The secondary seeding of the pasteurized milk by means of psychotrophics was carried out after the pasteurization along the whole technological route till its packing. The pasteurized milk packed in bottles showed a contamination with psychrotrophic microorganisms 4-6 times higher than that of milk packed in plastic bags. In the unboiled and in the pasteurized milk we found the psychrotrophic microorganisms of the species: Pseudomonas--respectively 64% and 53.8%, Micrococcus--8.2% and 30.7%, Enterobacter--9.8% and 2.6%, Bacillus--6.6% and 2.6%, Flavobacter--1.6% and 1.3% and Torula--2.6%. A comparatively high percentage (37.7%) of the isolated strains the psychrotrophic bacteria were lipolytic in the unboiled milk, 24.6%--proteolytic and 9.8% were simultaneously proteolytic and lipolytic. In the pasteurized milk 11.5% of the strains were lipolytic and 5.13% were proteolytic.

Animals↗

PubMed1980

Guidelines for the management of accidents involving microorganisms: a WHO memorandum.

The response to an emergency resulting from an accident involving microorganisms, whether in a laboratory or during needs to be graded according to the degree of hazard to human or animal health created by the circumstances of the accident and the properties of the organisms concerned. A categorization of microorganisms by risk groups is proposed for the purposes of accident management, and the factors influencing assignment to risk groups are described. Organizational responsibilities at government health authority and local levels are outlined and emphasis is placed on contingency planning. Medical surveillance is proposed for persons who work in laboratories with dangerous microorganisms, as a means of recognizing accidents that might otherwise go undetected. The response to exposure in a laboratory or transport-associated accident includes emergency safety measures at the site, hazard assessment, and action by the public health or veterinary authorities. The management of exposed persons is considered in relation to the immediate post-exposure period, the potential incubation period, and the onset of illness. Prophylactic treatment, surveillance, and the transport and isolation of infected persons are described. A distinction is drawn between the consequences of accidents recognized at the time of their occurrence and those that are only recognized by onset of illness in the exposed persons.

Accident Prevention↗

PubMedDate not supplied

[Role of microorganisms in the destruction of spodumene].

A broad spectrum of microorganisms has been shown to be involved in the destruction of spodumene, a typical mineral of lithium pegmatites. The following microorganisms are most active: the microscopic fungi Penicillium notatum and Aspergillus niger, the thiobacilli Thiobacillus thiooxidans, and the so-called "silicate" slime forming bacterium Bacillus micilaginosus n. sp. siliceus. Spodumene destruction is accompanied with lithium, aluminium and silicon being transferred into solution. The activity of this process depends on the microbial species, the pH of the medium, and some other factors. Lithium and aluminium are extracted best of all at acid pH values whereas silicon at alkaline pH values. Possible mechanisms for spodumene destruction by microorganisms are discussed.

Acidithiobacillus thiooxidans↗

PubMed1980

Microorganisms associated with abscesses of sheep and goats in the south of Iran.

A total of 86 abscesses (45 and 41) abscesses of sheep and goats, respectively) were examined for their causal agents; 44 of these abscesses were located subcutaneously, and the remaining 42 were in lungs, livers, intestines, and udders. A total of 23 different types of microorganisms were isolated from 78 abscesses; bacteria were not detected in the remaining eight abscesses. Microorganisms isolated were: species of the genera Corynebacterium, Staphylococcus, and Streptococcus and Pasteurella, Escherichia coli, and other gram-negative rods. Peptostreptococcus anaerobius and Eubacterium tortuosum were isolated in pure culture from one abscess each in goats. Two to four different microorganisms were associated with 25 of the 86 abscesses. It was determined that 11 isolates of Corynebacterium pyogenes, 2 isolates of Pasteurella haemolytica, 1 of P multocida, and 1 of C pseudotuberculosis were lethal to mice. Two of the C pyogenes isolates from subcutaneous spreading abscesses of goats were pathogenic for rabbits; these two isolates produced similar suppurative inflammation in goats experimentally, but did not cause death. As determined by experimental inoculation, goats were more susceptible than sheep to the two isolates. In nature, subcutaneous abscesses of goats associated with C pyogenes were of a more diffusive type which resulted in generalization of the infection and death of the animals. Postmortem examination of ten goats dying of field infection showed the presence of larvae of the warble-fly Przhevalskiana silenus at the site of infection.

Abscess↗

PubMedDate not supplied

[Use of the fluorescence method to detect and quantitatively determine lipids in the cells of microorganisms].

Techniques have been developed for the detection and quantitative determination of lipids in the living cells of microorganisms (after their fixation by heating) using benzimidazole luminophores synthesized by Monocrystalreactive (USSR). When the yeast cells are stained by a luminophore, the latter is selectively bound to cellular lipids producing a brightly fluorescent complex. The intensity of fluorescence increases proportionally to an increase in the concentration of lipids in the microbial mass. The intensity of fluorescence of a microbial suspension is recorded using a spectrofluorimeter at the excitation and fluorescence maxima of 405 and 475 nm respectively. In order to assay the content of lipids in microorganisms which do not produce a homogeneous suspension, the luminophore bound to lipids is extracted from the cells with hot octane. The absolute content of lipids in the biomass is determined using a standard curve which shows the intensity of fluorescence of microorganisms and their octane extracts as a function of the lipid content in the cell.

Ascomycota↗

PubMed1980

[Genome characteristics of a new group of microorganisms in the Vibrionaceae family].

A new group of microorganisms isolated from river and sewage water was studied by the method of molecular DNA-DNA hybridization and included into the family Vibrionaceae on account of their phenotypical properties. The genomes of the microorganisms belonging to this group proved to be highly similar (41-92% of homologies), which suggested that they were related on the genus level. The degree of similarity between the nucleotide sequences in the DNA of the bacteria under study and the DNA of other representatives of the family Vibrionaceae (the genera Vibrio, Beneckea, Aeromonas, Plesiomonas) amounting to 10-20% of homology indicates that the group of microorganisms under study forms a separate genus within the family Vibrionaceae.

Base Sequence↗

PubMed1980

[Blood cultures. Comparative study with 7 known and 2 new nutrient media for the detection of aerobic and anaerobic microorganisms (author's transl)].

The growth promoting properties of seven commercially manufactured and two recently developed culture media are compared according to a standardized method. The study is carried out alternately without and with the addition of 10% fresh human blood to the culture media. The carefully selected test strains include 20 species of bacteria and 2 species of yeasts which represent obligatory aerobic, facultative anaerobic and obligatory anaerobic microorganisms with quite different nutritional and atmospherical requirements. The 9 tested media are good enough for the purpose of culturing nonfastidious bacteria. However, most of the commercially prepared media failed to detect small inocula of very fastidious microbial agents, especially when no blood is added. Collectively, thiol broth is the most noneffective medium. The last but one is thioglycollate medium. Three culture media based on brain heart infusion formula prove to be effective. Those are the commercial brain heart dextrose and the two media recently developed by the authors, namely brain heart dipeptone (BHD) and brain heart dipeptone cysteine (BHDC). BHD is the most suitable medium for the detection of obligatory aerobic and facultative anaerobic fastidious microorganisms. BHDC detects anaerobic fastidious bacteria quite effectively. The other media, namely Columbia, trypticase soy, trypticase soy sucrose, and Rosenow are of limited value with regard to the detection of small inocula of fastidious microorganisms. The causes of the unsatisfactory results with different commercial media are discussed in detail. The authors point out to the possible use of hypertonic media in special cases. Properties that should be fulfilled by blood culture media are proposed.

Anaerobiosis↗

PubMed1980

Investigation of the safety of industrial strains of microorganisms and microbial insecticides.

Toxicology-hygienic studies of insecticidal preparations produced on the basis of fungi of the species Beauveria bassiana and bacteria of the species Bac. thuringiensis, recommended for use in plant-growing, were carried out. It has been established that the industrial strains of entomopathogenic microorganisms and insecticidal preparations produced on the basis of these microorganisms are harmless in the epidemiological sense and of low toxicity, but they may have a sensitizing effect on the human organism. On the grounds of results of toxicological experiments and hygienic observations in the field it has been concluded that prophylactic measures in the production and application of microbial insecticides should be aimed at restricting the contact of people with entomopathogenic microorganisms and preparations produced on their basis.

Animals↗

PubMed1995

Antibiotic treatment of adults with infective endocarditis due to streptococci, enterococci, staphylococci, and HACEK microorganisms. American Heart Association.

OBJECTIVE: To provide guidelines for the treatment of endocarditis in adults caused by the following microorganisms: viridans streptococci and other streptococci, enterococci, staphylococci, and fastidious gram-negative bacilli of the HACEK group. PARTICIPANTS: An ad hoc writing group appointed by the American Heart Association under the auspices of the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease in the Young. EVIDENCE: Published studies of the treatment of patients with endocarditis and the collective clinical experience of this group of experts. CONSENSUS PROCESS: The recommendations were formulated during meetings of the working group and were prepared by a writing committee after the group had agreed on the specific therapeutic regimens. The consensus statement was subsequently reviewed by standing committees of the American Heart Association and by a group of experts not affiliated with the working group. CONCLUSIONS: Sufficient evidence has been published that recommendations regarding treatment of the most common microbiological causes of endocarditis (viridans streptococci, enterococci, Streptococcus bovis, staphylococci, and the HACEK organisms) are justified. There are insufficient published data to make a strong statement regarding the efficacy of specific therapeutic regimens for cases of endocarditis due to microorganisms that uncommonly cause endocarditis. As a useful aid to the practicing clinician, the writing group developed a consensus opinion regarding management of endocarditis caused by the most commonly encountered microorganisms and regarding those cases due to infrequent causes of endocarditis.

Adult↗

PubMed1994

Comparison of utilization of pectins from various sources by pure cultures of pectinolytic rumen bacteria and mixed cultures of rumen microorganisms.

Utilization of citrus, lucerne, apple and sugar beet pulp pectins by pure strains of rumen bacteria, Prevotella ruminicola, Lachnospira multiparus and Butyrivibrio fibrisolvens was compared. Additionally, the utilization of pectins by mixed rumen microorganisms was evaluated. The comparison was based on the depletion of galacturonic acid from medium, content of cellular protein in the cultures and the amount of end products of pectin fermentation in cell-free culture fluids. It was found that citrus pectin was utilized best; utilization of lucerne, apple and sugar beet pectins was dependent on the species of bacteria. P. ruminicola and B. fibrisolvens utilized polygalacturonic acid from sugar beet pectins better than that from apple or lucerne pectin, while L. multiparus was capable of significantly better utilization of lucerne pectin than pectin from sugar beet or apple. The source of pectin was less important for mixed cultures of rumen microorganisms than for pure cultures of rumen bacteria. The amount of fermentation products in the culture fluids supported the conclusion that citrus pectin was utilized better than others. Microbial protein content in the cultures was found to be a less sensitive indicator of pectin utilization than the remaining examined parameters. P. ruminicola strains and mixed cultures of rumen microorganisms were shown to have the highest ability to utilize pectins, L. multiparus-moderate, while the B. fibrisolvens strains utilized pectin the least.

Animals↗

PubMed1994

Problems in the introduction of genetically engineered microorganisms into the environment.

The use and release of genetically engineered microorganisms (GEMs) into the environment, usually the agricultural environment, is increasing exponentially. Potential applications of GEMs include crop production, pest management, degradation of environmental pollutants, mining and mineral recovery, and others. Several strategies of molecular and cellular biotechnology, such as recombinant DNA techniques, nuclear microinjection and cell fusion may be used to modify bacteria and fungi for useful purposes. The benefits expected from release of genetically engineered microorganisms, if safely applied, might be substantial in various fields. However, a safe introduction of GEMs into the environment requires full environmental and ecological risks assessment. Because of the wide scope of genetic engineering targets this review will focus on the application of GEMs potentially useful in agricultural practices (crop nutrition, pest and disease control) and ecological problems associated with the introduction of alien microorganisms into the environment.

Agriculture↗

PubMed1995

[Possibilities of the use of gas-liquid chromatography in the identification of Nocardia microorganisms].

By determination of fatty acid composition of bacterial cells, gas-liquid chromatography can quickly identify Nocardia microorganisms isolated from the infected material. The study of fatty acid spectrum of the reference and fresh cultures Nocardia has found their homogeneity. Such fatty acids as hexadecenoic, hexadecanoic, octadecenoic, octadecanoic and tuberculostearic acids occurred most frequently. Differential criteria are proposed for Nocardia microorganisms basing on gas-liquid chromatography data on fatty acid spectra from mycobacteria to other nonmycobacterial acid-fast microorganisms.

Chromatography, Gas↗

PubMed1995

Extracellular and intracellular rickettsia-like microorganisms in gonads of mosquitoes.

The mosquitoes Culex tigripes, C. decens and C. quinquefasciatus have been investigated by electron microscopy. An intracytoplasmic rickettsia-like microorganism is present in ovaries and testes of the three species. An extracellular form of a rickettsia-like microorganism is described in the testis of C. tigripes in which it sometimes appears in great number. The extra- and intracellular forms present ultrastructural differences. The possibility they represent two different morphotypes of the same microorganism or simply two different types is discussed. They both disappear after treatment with tetracycline. This is believed to be the first electron microscope description of extracellular rickettsia-like cells in mosquitoes.

Animals↗

PubMed1994

The effect of L-tryptophane on yield of field bean and activity of soil microorganisms.

The pot trial was performed to study the effect of L-tryptophane (as an auxin precursor) applied in the amount 0.3 and 3.0 mg per 1 kg of the soil on yield and the chemical composition of field bean. The effects of this compound on dehydrogenases activity in the cells Rhizobium leguminosarum isolated from root nodules, soil dehydrogenases activity and number of microorganisms from different systematic or physiological groups were also studied. The effects of L-tryptophane were compared to indole-3-acetic acid (IAA) after application to soil in the rate 0.2 mg per 1 kg of the soil of foliar spraying in the rate 20 mg Din 1 dm3 of distilled water. Studies were carried out in three experimental series: without microorganisms or with addition of Azotobacter sp. or Rhizobium leguminosarum biovar. viciae to the soil. It was found that L-tryptophane and IAA did not affect the yield of above ground part and roots of field bean and their effects on macronutrients concentration were not direct and dependent on the nutrient and experimental series. L-tryptophane and auxine increased the dehydrogenases activity in the cells of Rhizobium leguminosarum isolated from root nodules and the effect on the activity of soil dehydrogenases and urease was dependent on the rate of L-tryptophane. This chemical adversely affected the numbers of some microorganisms groups.

Azotobacter↗

PubMed1994

[Composting facilities. 2. Aerogenic microorganism content at different working areas of composting facilities].

At two composting facilities (plants D and E), contamination of the air with total bacteria and mould fungi, and in addition with gram-negative bacteria (only at plant D) was analyzed at different indoor sites and outdoor in the vicinity. Statistical validity of the determination of contents of microorganisms in air samples was guaranteed by the collection and analysis of 30 parallel samples. At plant D, total bacteria concentrations in outdoor air ranged from 106 to 15,618 CFU/m3 air (median: 495 CFU/m3 air), gram-negative bacteria concentrations ranged up to 71 CFU/m3 air (median: below the detection limit of 35 CFU/m3 air), and mould fungi reached 7,138 CFU/m3 air (median: 141 CFU/m3 air). Highest concentrations of total bacteria above the upper detection limit (> 84,806 CFU/m3 air, sample volume: 28.3 l) and of mould fungi (38,940 CFU/m3 air) occurred at the place where three months old compost was mixed, highest concentrations of gram-negative bacteria (14,134 CFU/m3 air) were measured during mixing of fresh compost (younger than 8 days). Maximum and median values of the examined microorganisms ranged so high that special protective means for personnel working directly beneath the mixing process seem to be necessary under hygienic aspects. Raw and clean air at the composting filter at plant D showed highly significant differences concerning air concentration of gram-negative bacteria and mould fungi, indicating a good separation efficiency for these types of microorganisms. Maximum and median values of gram-negative bacteria and mould fungi concentrations (all < 1,000 CFU/m3 air) measured in clean air behind the composting filter lie in the range of normal outdoor air. Merely total bacteria show statistical significant differences to outdoor air with median values of clean air of 1,979 CFU/m3 air (edge of filter) resp. 3,110 CFU/m3 air (upside the filter) and with maximum values of above 30,000 CFU/m3 air in each case. In the outdoor air at plant E, total bacteria concentrations ranged from 362 to 7,633 CFU/m3 air (median: 1,312 CFU/m3 air), mould fungi ranged from 115 to 4,072 CFU/m3 air (median: 345 CFU/m3 air). Highest concentrations of total bacteria and mould fungi (all analyses above the upper detection limit of 21,201 CFU/m3 air; sample volume: 113,2 l) occurred during shredding of a mixture of kitchen and green wastes and of shrubs. During experimental shredding of separately collected panty diapers air concentrations of total bacteria ranged from about 19,000 CFU/m3 air to > 21,201 CFU/m3 air.(ABSTRACT TRUNCATED AT 400 WORDS)

Air Microbiology↗