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At least 595 records · Page 33Linked to original sources
PubMed1991

[Effects of sodium chloride on destruction of microorganisms by microwave heating in potatoes].

To assess the destructive effect of different sodium chloride concentrations (0, 0.3, 1.5, and 3%) on microorganisms with microwave heating, strains of Vibrio parahaemolyticus, Staphylococcus aureus, Salmonella enteritidis, Escherichia coli and Bacillus cereus were used to inoculate a mashed potato preparation. After microwave heating for 1 min at 800 W, resulted in temperatures and rate of destruction of bacteria significantly higher (p less than 0.05) in the core than on the surface of mashed potato when no salt was added. Except for B. cereus, microorganisms inoculated into mashed potato, with no added salt, could be completely destroyed by 2 min of microwave heating. Core temperatures and rate of destruction of microorganisms in the mashed potato decreased significantly (p less than 0.05) with increase in concentration of added salt. The results also indicate that bacterial species differ in their susceptibility to microwave inactivation. In particular, S. aureus, which exhibited a level of survival that was greater than that of any other species tested here, seemed notably resistant to microwave treatment for 2 min while V. parahaemolyticus was highly susceptible.

Bacteria↗
PubMedDate not supplied

[The sensitivity to antibiotics and disinfecting substances of opportunistic microorganisms isolated from the oral cavity of patients with orthodontic pathology].

Antibiotic and disinfectant sensitivities of opportunistic bacteria, isolated from the oral cavity of normal subjects and orthodontic patients, were under study. The findings evidence that oral microflora of patients with orthodontic conditions is more rich in microorganisms that can induce pyoinflammatory diseases than that in health. Among the isolated opportunistic bacteria strains were found that were resistant to both: antibiotics and disinfectants. Antibiotic sensitivities of the microorganisms isolated from normal subjects and patients were found virtually the same, whereas the strains isolated from the patients have shown a higher sensitivity to disinfectants. The authors emphasize that effective prevention of pyoseptic complications in the maxillofacial area involves not only bacteriologic monitoring and studies of the microorganism sensitivity to antibiotics, but analysis of the bacterial sensitivity to disinfectants as well.

Adult↗
PubMed1990

Comparison of large volume culture to other methods for isolation of microorganisms from dialysate.

Patients on continuous ambulatory peritoneal dialysis (CAPD) who reside long distances from a CAPD center often use community medical laboratories to document and manage episodes of peritonitis. We examined the feasibility of using large volume cultures as an alternative to more costly and labor intensive methods and to enhance earlier recovery of microorganisms from these patients. Three methods of processing dialysate from patients on CAPD were compared: (a) inoculation of 400 mL dialysate into a transfer bag (Baxter Healthcare, Inc., Round Lake, IL) containing 100 mL of 5-fold concentrate of trypticase-soy broth: (b) inoculation of 5 mL into each of two Bactec bottles (Johnston Laboratories, Towson, MD): and (c) centrifugation of 50 mL and culture of the sediment without white cell lysis on plated media and two Bactec bottles. Of the 58 specimens cultured, 34 (59%) were positive by one or more methods. Antimicrobial activity was detected in 20/58 (34%) dialysates, which represent 54% of all no-growth cultures. Of the 34 culture-positive specimens, microorganisms were recovered on plated media in 22 (65%); by the centrifugation system in 32 (94%); by the routine Bactec system in 28 (82%); and by large volume culture in 30 (88%). The large volume culture system is an acceptable alternative to the more costly Bactec System and the labor intensive centrifugation method but does not significantly improve recovery of microorganisms.

Bacterial Infections↗
PubMed1990

Monitoring antimicrobial drug resistance in hospital microorganisms. Definition of problems and methods.

Hospital infections continue to be an important problem. Changes in patient categories and in the examinations and treatments offered at the hospital, probably constitute the basis upon which new types of infections and new groups of infecting microorganisms continually emerge. The treatment of patients with hospital infections may become complicated by the emergence of drug resistance in the infecting microorganisms. The situation varies between hospitals, and this necessitates a local microbiological monitoring. Prerequisites of a surveillance system in general are described and illustrated by a system monitoring antimicrobial resistance in a Danish county. A specific computer system (software) for the processing of clinical microbiological results was developed by the author to make the local microbiological monitoring possible. Computer-assisted analyses for an evaluation of the statistical association of drug resistance traits (phenotype) were also developed. Data on local drug resistance patterns were systematically obtained and analysed in a seven-year study comprising several hundred thousands specimens. Drug resistance genotypes were determined for selected groups of microorganisms (e.g. coagulase-negative staphylococci) in various periods. Data from these studies emphasize that it is important to correlate information about resistance phenotypes of all clinical isolates with the resistance genotypes of selected strains in the monitoring of plasmid mediated resistance and its dissemination. These findings agree well with the results of other but generally less comprehensive studies in the literature. In a study of outpatients treated with a particular antimicrobial (tetracycline), it was shown that this drug selected for plasmid mediated multiple drug resistance in the normal flora of the patients. On the basis of these results and the literature, a general model for the emergence and spread of antimicrobial drug resistance is discussed. Examinations of quantitative relationships between antimicrobial usage and microbial resistance are also reviewed. Analysis of the statistical correlation between various measures of antimicrobial use and the prevalence of microbial resistance in the Danish county corroborates the observation that general changes in prevalence of a particular resistance trait seem to be best explained by taking the mechanisms of co-selection by other antimicrobials into consideration.

Anti-Bacterial Agents↗
PubMedDate not supplied

A model for the effect of real leaks on the transport of microorganisms into a vacuum freeze-dryer.

This paper proposes a model for determining the effect that real leaks, whose flow is viscous in nature, could have on the microorganism density in a vacuum freeze-dryer during a drying process. The model considers the entry of microorganisms to result from real leaks stemming from an environment containing a known bioburden. A means for determining the relationship between the rate of pressure rise of the system (ROR) and the density of microorganisms in a system, stemming from an environment of a known bioburden, is examined. The model also considers the change in the bioburden of the dryer with respect to variations in the primary and secondary drying process.

Air Microbiology↗
PubMed1989

Detection of microorganisms in clinical specimens using slides prestained with acridine orange (AOS).

Slides prestained with acridine orange (AOS) were used for direct examination of microorganisms in clinical specimens. The method is simpler than a commonly used acridine orange stain (AO) and has the advantage of being a supravital stain. Results indicate that the AOS method is sensitive, and allows rapid detection of microorganisms, even in the specimens containing few microorganisms, e.g. cerebrospinal fluid. Moreover AOS may be the choice method for detection of Trichomonas vaginalis.

Acridine Orange↗
PubMed1989

[A variety of microorganism species at the burn ward].

From 1975 to 1987, 965 exudate cultures of burn wounds were done in 553 cases. 1205 colonies (28 species) of microorganisms were separated out from these patients. Among 1205 colonies, 1050 colonies (87.13%) were "common microorganism" included P. aeruginosa, E. coli, S. aureus, and P. vulgaris. There were mixed infection of P. aeruginosa and E. coli in 23.66-25.95% cases. In early stage P. aeruginosa (23.25%) was predominant and in late stage, S. aureus was predominant. The sensitivity of microorganisms to 18 kinds of antibiotics gradually decreased, year by year. The authors consider that reasonable use of antibiotics, early eschar excision and skin grafting play an important role in decreasing the occurrence of drug-fast bacteria and preventing cross infection.

Anti-Bacterial Agents↗
PubMed1989

[Transformation of xenobiotics by soil microorganisms and their potential distribution].

Xenobiotics, i.e., unnaturally occurring organic substances, become transformed in soils, waters and ground water aquifers primarily by co-metabolism or by physico-chemical processes. The persistence of both xenobiotics and natural substances, i.e., time required for a 95% disappearance of the original compounds, is dependent on the chemical and physical characteristics of a compound itself (its molecular recalcitrance), on soil properties and conditions, and on the relationships of these factors. Among the specific factors which influence the persistence of individual compounds belong both natural and anthropogenic "non-physiological" characteristics and structures. Naturally occurring compounds become transformed metabolically, those with a xenobiotic character mainly co-metabolically. The degradation kinetics for both types of compounds have an exponential character, and according to a semi-logarithmic figure, it is a first order function (i.e., mineralization or transformation have a linear character). The co-metabolic processes depend closely on the concentration of the given compound in soil solution as well as on the general microbial activity. Metabolically utilizable compounds may serve microorganisms as sources of C, N, and eventually also of P and energy, after the necessary enzymes have become induced and synthetized. Co-metabolical compounds may not have these functions or microorganisms may require a long period to become adapted to them. In general, all means which support the microbial activity, may also support the co-metabolical transformations in the soil. This is especially true for aeration and manuring of soil both of which stimulate unspecifically the proliferation and activity of microorganisms, and indirectly also a co-metabolism of xenobiotics.

Bacteria↗
PubMed1989

[Study of dissemination and penetration of microorganisms in protective clothing].

Microorganism-protective working clothes should be considered one of the most important elements determining general culture of the production process, health state of the staff and technical and economic level of enterprises. In order to improve quality of special protective clothes, microbic contamination of overalls was studied in industrial premises with different levels of air bacterial contamination. Under laboratory conditions microorganism permeability of 15 articles of cotton cloth used for clothes weaving was also defined. Proceeding from the complex studies the recommendations on the use of fibre in microorganism-protective overalls' manufacture were presented.

Bacteria↗
PubMed1988

Multistep reactions with immobilized microorganisms.

This review presents some examples of new semicontinuous and continuous processes for product formation and for degradation of xenobiotics with immobilized microorganisms. A semicontinuous process for glycerol formation with Saccharomyces cerevisiae cells, adsorbed on sintered glass, and a continuous production of citric acid with Aspergillus niger, entrapped in calcium alginate, are given as examples of the production of primary metabolites. The production of ergot alkaloids with entrapped Claviceps purpurea demonstrates the possibilities of production of secondary metabolites. The continuous degradation of phenolic substances and that of 4-chlorophenol by entrapped and adsorbed microorganisms are given as examples of the possibility of a continuous degradation of xenobiotics by immobilized microorganisms. The continuous degradation of these substances was successful not only in artificial solutions but also in sterile and nonsterile wastewater.

Aspergillus niger↗
PubMed1988

Viability of microorganisms in fluorouracil and cisplatin small-volume injections.

The ability of various microorganisms to survive in cisplatin injection or fluorouracil injection in small-volume containers was assessed. Inoculum suspensions of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Pseudomonas cepacia, Candida albicans, or Aspergillus niger were injected into polyvinyl chloride minibags containing 20 mL of either fluorouracil injection 50 mg/mL or cisplatin injection 1 mg/mL in 0.9% sodium chloride injection. All minibags were stored at 25 degrees C for 28 days. Three minibags containing only the sodium chloride solution and 18 minibags containing the sodium chloride solution inoculated with microorganisms served as negative and positive controls, respectively. Samples (1 mL) were obtained within 30 minutes of inoculation and again on days 1, 2, 4, 7, 14, 21, and 28. All microbial species lost viability in both the cisplatin and the fluorouracil admixtures over the study period. In most instances, this loss was more pronounced than that in the positive control solution. Whether the pH of the solutions contributed to this loss of viability was not determined. Under the conditions of this study, admixtures containing cisplatin and fluorouracil did not support rapid growth of microorganisms when stored at room temperature for up to 28 days.

Bacteria↗
PubMedDate not supplied

[Analysis of the thermostability of the hybrid DNA molecules of microorganisms as a means of increasing the resolution of the molecular hybridization technic].

A comparative study of termostability of microorganisms DNA was performed in order to increase the resolution of the method of molecular hybridization. Molecular hybridization was carried out and the curve of hybrid DNA duplexes distribution, acccording to termostability of two groups of microorganisms, related to strains Echerichia coli B1 and Vibrio cholerae eltor 18647, were obtained. It was determined that the form of the curves is specie specific for the microorganisms investigated but there exists a similarity between the closely related strains which can not be distinguished by the percent of homology.

Base Sequence↗
PubMedDate not supplied

[Aniline oxidation by microorganisms in chemostat cultivation].

Under the conditions of chemostat cultivation, a mixed culture of microorganisms oxidized aniline at a gradually increasing concentration (up to 2.5 g/litre) as a sole source of carbon and nitrogen. The specific rate of aniline oxidation was as high as 160 mg per 1 g of dry biomass when aniline concentration in the growth medium was 2.5 g/litre. As aniline concentration in the growth medium was gradually raised, selection of the microorganisms took place and the number of the strains decreased from ten to two. The growth rate of the microorganisms fell down abruptly when phosphorus concentration in the medium was below 35 mg per 1 g of aniline.

Alcaligenes↗
PubMed1985

Colonization of the oropharynx with pathogenic microorganisms--a potential risk factor for infection in compromised patients.

The indigenous oropharyngeal microflora is complex and consists of many different aerobic and anaerobic microorganisms. Nonindigenous pathogenic microorganisms do not normally colonize the oropharynx due to several different defense mechanisms such as cell specific bacterial attachment, secretion of antibacterial substances and immunoglobulins. Also microbial interactions play an important role in the prevention of new colonization of the oropharynx. Suppression of the indigenous flora by antibiotics promote new colonization. Patients that are severely compromised by disease may be infected by colonizing microorganisms. At special risk are patients with low neutrophil count and patients that are prone to aspiration pneumonia. Thus new colonization should be prevented in such risk patients. Careful monitoring of systemic antimicrobial therapy is essential and decontamination of oropharynx with local antimicrobial agents may be of value.

Attachment Sites, Microbiological↗
PubMedDate not supplied

[Vertical distribution and the characteristics of the species composition of the microorganisms of some stratified lakes in Estonia].

The total number, vertical distribution, and special composition of microorganisms from three stratified lakes in the South-Eastern Estonia containing hydrogen sulfide and ferrous iron were studied in March, 1976. The number of bacteria was lowest in surface water samples (1.2-1.9 x 10(6) cells/ml). It increased first in the zone where oxygen disappeared (2.4-7.6 x 10(6) cells/ml), then slightly decreased, and again increased near the bottom where it became maximal (3.7-14.0 x 10(6) cells/ml). The vertical distribution of individual microbial species corresponded to ecological niches. The content of Spirillum and Flexibacter, colonies of parallel rods containing gaseous vacuoles, was highest in the zone in which oxygen was still present. Iron bacteria, purple sulfur bacteria, colourless sulfur bacteria, and green bacteria Chloronema appeared deeper, in the microaerophilic conditions. Ancalochloris perfilievil, Chloroplana vacuolata, Chlorochromatium aggregatum, Pelochromatium roseum, Hyalosoris sp., and Peloploca sp. were found in the strictly anaerobic conditions. Morphological forms of microorganisms were most versatile in the region of contact between the aerobic and anaerobic zones. Most of the morphologically peculiar species of microorganisms were detected in all three lakes, but some bacterial forms were typical of some of the lakes.

Ecology↗
PubMedDate not supplied

[Total number and biomass of microorganisms in the depths of the Black Sea].

The total number and biomass of microorganisms, as well as the ratio between their main morphological forms, were determined by capillary microscopy in 22 water samples taken at various depths from the surface to 1500 m in the eastern part of the Black Sea. The total number of microorganisms was several times higher at depths over 150 m in the hydrogen sulfide zone than in the oxygen zone (0--150 m), whereas the biomass was greater by an order of magnitude. The number of microorganisms varied within a range of 1.4--12.4X10(3) cells/ml in the oxygen zone and 3.8--34.9X10(3) cells/ml in the hydrogen sulfide zone, whereas the biomass was 0.9--6.9 mg/m3 and 10.8--55.6 mg/m3, respectively. The bulk of the microbial biomass in the hydrogen sulfide zone was constituted by peculiar filamentous forms described for the first time by Lebedeva (1953, 1963) and, apparently, participating in sulfur turnover.

Bacteria↗
PubMedDate not supplied

[Hydrocarbon-oxidizing microorganisms in the waters of certain regions of the Western and Central Atlantic].

The incidence of hydrocarbon-oxidizing microorganisms in water was determined by the method of plating on solid media. Vertical distribution of hydrocarbon-oxidizing microflora was different near the shore and in the open ocean; the incidence of the microorganisms was low in the surface water layer but increased at depths of 25 and 75 m in the open ocean in contrast to regions near the shore. Pure bacterial and fungal cultures were isolated and their properties were described. The cultures were grown in a liquid mineral medium with diesel fuel and 50 cultures out of 66 were found to be true hydrocarbon-oxidizing microorganisms surviving under the laboratory conditions. It was shown that bacteria and fungi have grown on tarballs collected from the surface of the ocean during their incubation at 30 degrees C.

Bacteria↗
PubMed1983

Application of scanning electron microscopy to the study of microorganisms in gastrointestinal pathobiology.

This review describes the application of SEM to the study of microorganisms in gastrointestinal (GI) pathobiology. SEM has proven to be a highly useful tool with a variety of applications in the biological and medical sciences. Examples in this paper are focused on the use of secondary electron imaging to study selected bacterial (cholera), fungal (candidosis), and protozoan (giardiasis) diseases in the GI tract of murine (mouse and rat) experimental models. The successful application of SEM to studies of microorganisms in GI pathobiology requires strict attention to optimal preparative techniques, to selection of the appropriate method and microenvironment(s) for study, and to awareness of the indigenous microorganisms characteristic of the system studied.

Animals↗