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PubMed1989

[The effect of microbial protein from a hydrocarbon base (fermosin) with a defined fatty acid composition on fat metabolism and fat composition in slaughter animals. 2. The effect of "fermosin" on the composition of back fat in hogs].

Two tests have been undertaken to investigate the influence of feeding microbial biomasses to pigs. No alterations of the fat parameters characterizing the fat stability were observed. All the values obtained are in a normal range. Increases in heptadecenic acid were detected dependent on the content of microbial biomasses in the feed and its fat content. The alterations are mainly in a normal range or slightly beyond it. In nature odd-numbered fatty acids are ubiquitous. Uptake and storage suggest that the organism reacts to an increased offer of C17-fatty acids with an accelerated decomposition of these fatty acids or/and with inhibition of their endogenous synthesis. The results are discussed in comparison with those of literature.

Adipose Tissue↗

PubMedDate not supplied

Toxicity of miserotoxin and its aglycone (3-nitropropanol) to rats.

The toxicity of miserotoxin (3-nitro-1-propyl-beta-D-glucoside) and its aglycone, NPOH, were compared in rats. Miserotoxin, a component of certain legumes, was relatively innocuous given orally (LD50 greater than 2.5 g/kg) but NPOH (LD50 = 77 mg/kg) was at least 10 times more toxic. Miserotoxin was readily absorbed from the upper regions of the digestive tract but the degree of gastrointestinal hydrolysis was small. The low toxicity of miserotoxin was attributed to a low level of microbial hydrolysis. NPA was not detected in the gastrointestinal tract during miserotoxin digestion. A simple method for isolating miserotoxin by column chromatography is described.

1-Propanol↗

PubMed1990

Piezoelectric crystal biosensors.

The recent development of piezoelectric devices as biosensors is reviewed. Biological materials, like enzymes, lipids, antibodies and antigens, have been used as specific coatings and were utilized for the determination of different substrates. Methods of protein coating and several applications are reported including microgravimetric immunoassays, microbial assays, DNA hybridization, enzyme detections and gas phase biosensors. Although the piezoelectric immunochemical sensor is convenient to use and very promising, a thorough understanding of the different phenomena associated with crystals frequency measurement in biological reactions is still lacking and deserves further investigation.

Antibodies↗

PubMed2004

Potential of DNA microarrays for developing parallel detection tools (PDTs) for microorganisms relevant to biodefense and related research needs.

Development of parallel detection tools using microarrays is critically reviewed in view of the need for screening multiple microorganisms in a single test. Potential research needs with respect to probe design and specificity, validation, sample concentration, selective target enrichment and amplification, and data analysis are discussed. Data illustrating selected probe design issues for detecting multiple targets in mixed microbial systems is presented. Challenges with respect to cost, time, and ease of use compared to other methods are also summarized.

Animals↗

PubMed2005

Observation of bias associated with re-amplification of DNA isolated from denaturing gradient gels.

DNA from environmental PCR products separated by denaturing gradient gel electrophoresis (DGGE) was isolated from the background smear rather than from discrete bands of the DGGE gel. The "interband" region was considered as a potential source of less dominant members of natural microbial communities. Surprisingly, instead of detecting new bands from the re-amplified PCR products, patterns very similar to the original ones were obtained regardless of the position of the "interband" region. The results suggest that the separation of amplicons by DGGE may not be perfect and band re-amplification based sequence analyses need careful interpretation.

DNA, Ribosomal↗

PubMed2005

Computers in anesthesia and intensive care: lack of evidence that the central unit serves as reservoir of pathogens.

OBJECTIVE: Computers are becoming increasingly visible in operating rooms (OR) and intensive care units (ICU) for use in bedside documentation. Recently, they have been suspected as possibly acting as reservoirs for microorganisms and vehicles for the transfer of pathogens to patients, causing nosocomial infections. The purpose of this study was to examine the microbiological (bacteriological and mycological) contamination of the central unit of computers used in an OR, a surgical and a pediatric ICU of a tertiary teaching hospital. METHODS: Sterile swab samples were taken from five sites in each of 13 computers stationed at the two ICUs and 12 computers at the OR. Sample sites within the chassis housing of the computer processing unit (CPU) included the CPU fan, ventilator, and metal casing. External sites were the ventilator and the bottom of the computer tower. Quantitative and qualitative microbiological analyses were performed according to commonly used methods. RESULTS: One hundred and ninety sites were cultured for bacteria and fungi. Analyses of swabs taken at five equivalent sites inside and outside the computer chassis did not find any significant-number of potentially pathogenic bacteria or fungi. This can probably be attributed to either the absence or the low number of pathogens detected on the surfaces. CONCLUSION: Microbial contamination in the CPU of OR and ICU computers is too low for designating them as a reservoir for microorganisms.

Anesthesiology↗

PubMed2004

Toll-like receptors: linking innate and adaptive immunity.

Detection of and response to microbial infections by the immune system depends largely on a family of pattern-recognition receptors called Toll-like receptors (TLRs). These receptors recognize conserved molecular products derived from various classes of pathogens, including Gram-positive and -negative bacteria, DNA and RNA viruses, fungi and protozoa. Recognition of ligands by TLRs leads to a series of signaling events resulting in induction of acute responses necessary to kill the pathogen. TLRs are also responsible for the induction of dendritic cell maturation, which is responsible and necessary for initiation of adaptive immune responses. Although TLRs control induction of adaptive immunity, it is not clear at this point how responses are appropriately tailored by individual TLRs to the advantage of the host.

Animals↗

PubMed2002

Whole genome amplification--applications and advances.

The concept of whole genome amplification is something that has arisen in the past few years as the polymerase chain reaction (PCR) has been adapted to replicate regions of genomes that are of biological interest. The applications are many--forensic science, embryonic disease diagnosis, bioterrorism genome detection, "immortalization" of clinical samples, microbial diversity, and genotyping. Several recent papers suggest that whole genomes can be replicated without bias or non-random distribution of the target, these findings open up a new avenue to molecular biology.

Animals↗

PubMed2005

Oxidative degradation of glyphosate and aminomethylphosphonate by manganese oxide.

Glyphosate (N-(phosphonomethyl)glycine), the most commonly used herbicide worldwide, degrades relatively rapidly in soils under most conditions, presumably by microbial processes. The most frequently detected degradation product in soil and water is AMPA (aminomethylphosphonic acid). We report the first evidence for an abiotic pathway of glyphosate and AMPA degradation under environmentally realistic conditions. Both glyphosate and AMPA degraded at 20 degrees C in dilute aqueous suspensions of birnessite, a manganese oxide common in soils, as evidenced by the accumulation of orthophosphate in solution over a period of several days. It is concluded that the abiotic degradation involved C-P bond cleavage at the Mn oxide surface, although evidence for C-N bond cleavage in the case of glyphosate and sarcosine, a likely degradation product of glyphosate, was found. The degradation of glyphosate was faster than that of AMPA, and higher temperature (50 degrees C) resulted in faster degradation of both glyphosate and AMPA. The addition of sulfate to the solution had no marked effect on the reaction rate, although Cu2+ addition inhibited degradation. As this metal ion complexes strongly with glyphosate, the inhibition can be attributed to the ability of Cu2+ to limit glyphosate coordination to reactive oxidation sites at the Mn oxide surface. Using a similar experimental design, we were unable to detect glyphosate degradation in an equimolar solution of MnCl2 (0.5 mM). However, we demonstrated that the oxidation of Mn2+ is enhanced both in solution and on an inert surface, in the presence of glyphosate (4:1 Mn-glyphosate molar ratio). This result suggests that the oxidative breakdown of glyphosate in the presence of Mn2+ may ultimately occur following the spontaneous oxygen-mediated oxidation of manganese.

Glycine↗

PubMed2005

Identification and quantification of epsilon-(gamma-glutamyl)lysine in digests of enzymatically cross-linked leguminous proteins by high-performance liquid chromatography-electrospray ionization mass spectrometry (HPLC-ESI-MS).

A rapid and convenient method for the precise quantification of epsilon-(gamma-glutamyl)lysine isopeptide in lyophilized proteolytic digests of cross-linked plant protein samples was developed. The isopeptide was baseline-separated from three other isomers containing lysyl and glutamyl residues by reverse-phase high-performance liquid chromatography after exhaustive proteolytic digestion of the samples cross-linked by a microbial transglutaminase (MTG). Highly selective detection was performed by electrospray mass spectrometry in MS/MS mode. Demonstrating the applicability of the suggested analytical procedure, enzymatic cross-linking of protein isolates from soy [Glycine max (L.) Merr.], pea [Pisum sativum L.], and the sweet lupin species Lupinus albus L. and Lupinus angustifolius L. was investigated after incubation with 0.01 g of MTG/100 g of protein for 0-240 min at 40 degrees C. The liquid chromatography-mass spectrometry (LC-MS) method was successfully applied to monitor the kinetics of epsilon-(gamma-glutamyl)lysine isopeptide formation. Since the calculated initial levels of epsilon-(gamma-glutamyl)lysine in the genuine leguminous protein isolates were between 40 and 77 micromol/100 g, an isopeptide detection limit of 0.5 microg/mL, corresponding to approximately 50 micromol/100 g of protein, was shown to suffice for quantifying the cross-linking rate enzymatically induced by MTG. Concentrations of epsilon-(gamma-glutamyl)lysine in the texturized proteins ranged from 100 to 500 micromol/100 g of protein.

Chromatography, High Pressure Liquid↗

PubMed2002

Simultaneous flow cytometric analysis of phagocytosis and oxidative burst activity in equine leukocytes.

This paper describes a method for simultaneously measuring phagocytosis and oxidative burst activity in equine peripheral blood leukocytes by flow cytometry. Opsonized propidium iodide-labelled Staphylococcus aureus (PI-Sa) was used to measure the uptake of bacteria by equine phacocytes and the oxidative burst activity by oxidation of dihydrorhodamine 123. The requirements to achieve optimal activity of phagocytosis and oxidative burst are described. The advantage of the simultaneous technique is that it provides both independent and comparative values for phagocytosis and the oxidative burst, for the detection of impaired mechanisms of microbial destruction. Furthermore, the technique allows evaluation of opsonization activity in this context.

Animals↗

PubMed1998

The genome sequence of Rickettsia prowazekii and the origin of mitochondria.

We describe here the complete genome sequence (1,111,523 base pairs) of the obligate intracellular parasite Rickettsia prowazekii, the causative agent of epidemic typhus. This genome contains 834 protein-coding genes. The functional profiles of these genes show similarities to those of mitochondrial genes: no genes required for anaerobic glycolysis are found in either R. prowazekii or mitochondrial genomes, but a complete set of genes encoding components of the tricarboxylic acid cycle and the respiratory-chain complex is found in R. prowazekii. In effect, ATP production in Rickettsia is the same as that in mitochondria. Many genes involved in the biosynthesis and regulation of biosynthesis of amino acids and nucleosides in free-living bacteria are absent from R. prowazekii and mitochondria. Such genes seem to have been replaced by homologues in the nuclear (host) genome. The R. prowazekii genome contains the highest proportion of non-coding DNA (24%) detected so far in a microbial genome. Such non-coding sequences may be degraded remnants of 'neutralized' genes that await elimination from the genome. Phylogenetic analyses indicate that R. prowazekii is more closely related to mitochondria than is any other microbe studied so far.

DNA Replication↗

PubMed2002

Advances in research of the inflammatory response: the importance of toll-like receptors.

The innate immune system provides the first line of defence against invading pathogens. Cells that mediate the innate immune response express a variety of receptors that permit recognition of pathogen-associated motifs, subsequently resulting in a cascade of responses that initiates inflammation. Recently, the members of the Toll-like receptor family (TLR) have emerged as key receptors responsible not only for the detection of a variety of microbial cell-wall components and bacterial DNA but also for the initiation of signal transduction events eventually leading to the production of various proinflammatory mediators.

Animals↗

PubMed1975

Nationwide epidemic of septicemia caused by contaminated infusion products. IV. Growth of microbial pathogens in fluids for intravenous infusions.

Septicemia caused by contaminated infusion fluid is a newly appreciated hazard of intravenous infusion therapy. Microorganisms of the tribe Klebsielleae (Klebsiella, Enterobacter, and Serratia) have predominated in these infections. Members of this tribe found to possess a selecive ability over common non-Klebsielleae microbial pathogens to proliferate rapidly in commerical parential fluids contaning clucose at room temperautre. Fifty-one Klebsielleae strains, washed twice before inoculation of approximately 1 organism/ml, attained a mean normalized 24 hr concentration of 1.11 x 10-5 organisms/ml in 5% dextrose in water at 25 C. In contrast, 48 of 49 non-Klebsielleae bacterial strains (clinical isolates of Staphylococcus, Proteus, Escherichia coli, Herelea, and Pseudomonas aeruginosa) slowly died (mean 24-hr concentration, 0.2 organism/ml). Five Candida albicans strains frew only very slowly (31.3 organisms/ml). Even with concentrations exceeding 10-6 organisms/ml, microbial presence was never visibly detectable. The significant increases in cases of nosocomial spticmia caused by Klebsiella, Enterobacter, and Serratia in recent years might be attribuatble in part to fluid-related spesis accompanying the expanding use of parenteral therapy.

Bacteria↗

PubMed1984

Antimicrobial properties and microbial contaminants of breast milk--an update.

A review of recent studies of antibacterial, antiviral and antiprotozoan factors in human breast milk is presented. Also reviewed are the microbial contaminants that have been detected in human milk with a particular focus on cytomegalovirus and rubella virus, both of which have recently been shown to infect infants via breast milk.

Antibodies↗

PubMed2005

Epidemiology of community-acquired pneumonia in adult patients at the dawn of the 21st century: a prospective study on the Mediterranean coast of Spain.

This study presents data from a prospective study of adult patients with community-acquired pneumonia (CAP). Of 493 patients included in the study, 223 (45.2%) were aged > or = 65 years, and 265 (53.7%) had one or more underlying diseases, mostly chronic obstructive pulmonary disease, diabetes mellitus or dementia. In total, 281 microorganisms were identified in 250 (50.7%) patients, with two or more pathogens detected in 28 (5.7%) cases. Microbial diagnosis varied according to age, severity, co-morbidity and site-of-care, but there was much overlap among groups. Streptococcus pneumoniae was the single most prevalent organism in outpatients, patients admitted to hospital, and patients who died, either as a single pathogen or combined with another organism. Infections caused by 'atypical' pathogens were seen across all groups, including the elderly and patients with co-morbidities. Mortality varied according to the pneumonia severity index (PSI) of the pneumonia patient outcomes research team. Shock (OR 34.48), an age of > 65 years (OR 25) and altered mental status (OR 9.92) were factors associated independently with 30-day mortality. Key findings from this study were the advanced age of the population with CAP, and the high prevalence of dementia as an underlying disease. The study also revealed that microbiological diagnosis of CAP remains problematic. Although certain epidemiological features may help to predict the microbial aetiology, the overlap among groups reduces the usefulness of this information in guiding therapeutic decisions. Greater effort should be made to improve identification methods for microbial pathogens causing CAP.

Adolescent↗

PubMed2005

Proportional distribution of the red complex and its individual pathogens after sample storage using the checkerboard DNA-DNA hybridization technique.

BACKGROUND: Information on the impact of sample storage prior to analysis by DNA methods is limited. AIMS: To investigate the effect of microbial sample storage on bacterial detection and proportional distribution of the red complex and its individual pathogens. MATERIAL AND METHODS: Subgingival plaque samples were analysed by (1) immediate processing, (2) after storage at +4 degrees C for 6 weeks, (3) after storage at -20 degrees C for 6 months or (4) after storage at -20 degrees C for 12 months using the checkerboard DNA-DNA hybridization. RESULTS: Proportional distribution of the red complex did not differ between the first three protocols. However, the total bacterial DNA for pathogens studied decreased significantly in protocols 3 and 4. Relative amounts of Tannerella forsythensis, Porphyromonas gingivalis and Treponema denticola remained stable in the second protocols and changed in an unpredictable way if stored for 6 or 12 months. CONCLUSIONS: Results from samples stored for maximum 6 months at -20 degrees C with high proportional amounts of the red complex and T. denticola may be used as an indicator of persistence. All bacterial samples for DNA extraction should be processed following a standardized storage protocol (i.e. samples stored at +4 degrees C for maximum 6 weeks) in order to get comparable qualitative and quantitative results for total DNA, bacterial complexes and individual pathogens. Most representative results are yielded if processing and hybridization could be performed immediately after sampling.

Analysis of Variance↗

PubMed1981

Limulus amoebocyte lysate and direct sampling methods for surveillance of operating nebulizers.

The Limulus amoebocyte lysate test for detection of endotoxin (Pyrogent; Mallinckrodt Chemical Co.) and the Easicult method (Orion Diagnostica) for detection of bacteria were compared with direct dilution sampling, a standardized technique for respiratory therapy surveillance previously developed in our laboratory. Tests of 206 reservoirs of nebulizers were done in three hospitals in Georgia. Forty-five percent of all reservoirs sampled were contaminated. Gram-negative, nonfermentative bacilli were the predominant contaminants. The results of the Limulus test and the Easicult system were in agreement with those of the direct dilution sampling tests approximately 84 and 90% of the time, respectively. Direct dilution of water samples onto blood agar plates was the most sensitive, reliable, and informative method for detecting viable bacteria. The Easicult and Limulus systems were sensitive enough to detect greater than or equal to 10(3) colony-forming units per ml. Positive Limulus tests and negative culture tests, reflecting detection of endotoxin but not of viable gram-negative bacteria, occurred in 20 of 206 (9.7%) instances. Positive cultures and negative Limulus tests were noted in 13 of 206 (6.8%) samplings. The Limulus test is a valuable procedure, for it can detect moderate-to-heavy microbial contamination within 1 h of testing and affords the opportunity to remove contaminated equipment from patients within minutes of a positive test result. These results demonstrate the potential value of the Easicult and Limulus tests for selective surveillance of operating nebulizers.

Acinetobacter↗