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PubMed1994

[Nosocomial pneumonias. The effect of selective intestinal and ventricular decontamination in respirator-treated intensive care patients].

Nosocomial infections, especially pneumonias, are a common problem in Intensive Care Units (ICU) and are a major cause of morbidity and mortality. During the past ten years a new regime, selective decontamination of the digestive tract (SDD) has been introduced to prevent these infections which are often preceded by colonization with aerobic potentially pathogenic microorganisms. Topical antibiotics are applied both orally and by nasogastric tube to prevent secondary endogeneous infections with Gram-negative enteric rods, Staphylococcus aureus and yeasts, in combination with parenteral antibiotics for the treatment of early primarily exogeneous and endogeneous infections. The effect of SDD on morbidity and mortality has been studied in many papers which are very conflicting and their results are difficult to interpret. This article reviews 11 published randomized trials of SDD in ICU among intubated and artificially ventilated adult patients aged more than 15 years. Of the eleven available controlled studies, eight showed a significant reduction of nosocomial pneumonias among patients who received selective decontamination. Only two studies demonstrated a reduction in infection related mortality rates.

Adult↗
PubMed1994

Incorporation of body components of diverse microorganisms by larval mosquitoes.

A pulse-purge schedule of exposure to labeled microorganisms was used to compare their digestibility by larval mosquitoes. Larvae were placed for an hour in suspensions of diverse axenically grown microorganisms that had been labeled with radioactive carbon (in the form of glucose or glycine). The guts of these mosquitoes were then purged with nonlabeled Sephadex particles for 30 min, and retained radioactivity was measured. Larvae imbibed no dissolved material. Larval mosquitoes differ in their capacity to derive label from algae (sensu lato), and certain algae contribute more label to these mosquitoes than do others. The nature of any algal food, as well as the feeding habits and developmental stage of the larva, influence its capacity to derive label from algae. This pulse-purge method of analysis can assist in the selection of algal "vectors" suitable as vehicles for transgenic larvicide. Although larval mosquitoes fail to assimilate the contents of Palmellacoccus cells with which they are confined, as much as 1/3 of the body contents of a Euglena gracilis cells become incorporated into their bodies. Because larval mosquitoes internalize more material from Euglena than they do from various other algae, these microorganisms provide a promising candidate vehicle for transgenic Bacillus thuringiensis israelensis.

Aedes↗
PubMed1992

Effect of piperacillin/tazobactam therapy on intestinal microflora.

The effect of piperacillin/tazobactam treatment upon the intestinal microflora was studied in 20 patients with intraabdominal infections. The patients received piperacillin 4 g combined with tazobactam 500 mg q 8 h by intravenous injection for 4-8 days. Stool specimens were collected before, during and after therapy for cultivation of aerobic and anaerobic microorganisms. Six patients had measurable concentrations of piperacillin (1.2-276 mg/kg/faeces) and 4 patients tazobactam concentrations (0.8-22.2 mg/kg/faeces) in the faecal specimens during therapy. The number of enterobacteria and enterococci slightly decreased while there were no changes in the number of staphylococci and bacilli. The anaerobic microflora was also slightly affected. There was a minor decrease in the number of bifidobacteria, eubacteria, lactobacilli, clostridia and veillonella but the numbers of anaerobic Gram-positive cocci and bacteroides were not influenced by the treatment. After therapy, the aerobic and anaerobic microflora returned to normal levels in all patients. None of the patients had Clostridium difficile or cytotoxin in the stools or developed diarrhoea.

Adult↗
PubMed1980

[Implications of the incorporation of transisomers of unsaturated fatty acids into cell membranes].

The incorporation of dietary trans fatty acids is shown into intestinal brush border and heart mitochondrial membranes obtained from rats fed with either partially hydrogenated soybean oil or with a synthetic triglyceride containing elaidic or linelaidic acid. The distribution of dietary linelaidate in the major phospholipid classes from inner membranes of mitochondria is determined. Heart mitochondria from normal rats and linelaidic acid fed rats are compared with respect to their swelling rate and their oxidative phosphorylation. The influence of dietary linelaidate on the activity of some brush border-associated enzymes is also studied. On the basis of the authors' observations and those made by others with microorganism cels or models of biological membranes (liposomes and monomolecular films), the possible implications of trans fatty acids incorporation on membrane functions are reviewed.

Animals↗
PubMed1999

Lactobacilli isolated from chicken intestines: potential use as probiotics.

Lactobacillus strains were tested for their in vitro probiotic properties. Cell surface hydrophobicity was found to be very high for Lactobacillus fermentum subsp. cellobiosus and Salmonella Gallinarum; high values could indicate a greater ability to adhere to epithelial cells. Studies on Lactobacillus animalis indicated relative cell surface hydrophobicities smaller than those of L. fermentum subsp. cellobiosus and L. fermentum. L. animalis and Enterococcus faecalis were able to coaggregate with L. fermentum subsp. cellobiosus and L. fermentum, respectively, but not with Salmonella Gallinarum. After mixed-culture studies for determining suitable growth behavior, the pair of strains L. animalis plus L. fermentum subsp. cellobiosus was selected for an attempted challenge against Salmonella Gallinarum. Double and triple mixed-culture studies indicated that selected lactobacillus strains were able to retain their beneficial characteristics in the presence of Salmonella Gallinarum such as presence of lectins, production of antimicrobial compounds, and ability to grow and compete. The selected microorganisms can be considered as potential ingredients for a chicken probiotic feed formulation intended to control salmonellosis and also improve poultry sanitation.

Animals↗
PubMed1994

In vitro transformation of the Fusarium mycotoxins deoxynivalenol and zearalenone by the normal gut microflora of pigs.

The biotransformation of the Fusarium mycotoxins deoxynivalenol and zearalenone by the normal bacterial gut flora of pigs was examined in this in vitro study. For that purpose, suspensions of intestinal contents (duodenum, jejunum, caecum, colon, rectum) of porcine origin were incubated anaerobically with deoxynivalenol (DON) or zearalenone (ZEA). DON and ZEA were degraded by the flora of the caudal segments (caecum, colon, rectum) of the gut--particularly the colon content--whereas the microorganisms of the cranial segments (duodenum, jejunum) exhibited no transforming activity. DON was showed to be deepoxidated, ZEA was hydrolyzed to alpha-zearalenol and an unknown metabolite. The transformation of DON was correlated with a loss of cytotoxicity, which could be demonstrated in the MTT(3-[4,5-dimethylthiazol-2yl]-2,5-diphenyltetrazolium++ + bromide)-cell-culture assay using swine kidney cells as target cells. The results of the study presented here correspond with the data found in in vivo studies. On the basis of these findings one could conclude that this in vitro method seems to be well suited to the study of the transformation of mycotoxins by the microflora of the gut. The in vitro study is cheaper than a feeding trial, and the preliminary information on the metabolism of mycotoxins obtained in such studies is helpful in designing feeding trials more clearly. Besides the simple and fast handling, reproducibility and the protection of the animals studied are further advantages of this in vitro method. In connection with the MTT-cell-culture assay, additional information about the cytotoxic potential of the bacterial transformation products can be obtained.

Animals↗
PubMed1998

The effect of lactic acid bacteria on intestinal metabolism and metabolic profile in gnotobiotic pigs.

The effect of inoculation of Lactobacillus casei on selected parameters of metabolic profile and intestinal metabolism of gnotobiotic piglets was investigated during the first three weeks of their life. The experiment was carried out on 8 germ-free piglets. The experimental group was inoculated once a day with the Lactobacillus casei subsp. casei strain. The inoculum contained 1 x 10(8) microorganisms in 1 ml. The control group of piglets received no inoculum. Lactobacillus casei colonized jejunum and ileum in the numbers from 5.63 to 6.06 log 10 cm-2 and their numbers in the jejunal and ileal contents were in the range 8.38-9.87 log 10.ml-1. The daily consumption of milk by the inoculated animals was significantly higher (p < 0.001). The average weight of inoculated piglets at the end of the period investigated was higher by 29.7%. Lactobacillus casei affected several parameters investigated. Piglets inoculated with lactobacilli showed significantly lower (p < 0.05-0.01) values of pH of the jejunal content, numbers of erythrocytes, values of haematocrit, urea, glucose, total lipids, cholesterol and calcium in the serum and significantly higher values (p < 0.05-0.01) of lactic acid in the jejunal content. The values of phagocytic activity and the index of phagocytic activity in the piglets of the experimental group were two to three-fold higher in comparison with those detected in the control group. The application of Lactobacillus casei affected positively the growth of gnotobiotic piglets, their intestinal metabolism, the level of cholesterol in the serum and phagocytic activity.

Animals↗
PubMed2002

Characterization of yellow-pigmented and motile enterococci isolated from intestines of the garden snail Helix aspersa.

AIMS: Enterococci associated with garden snails (Helix aspersa) were studied in order to obtain reliable species identification and characterization. METHODS AND RESULTS: Twelve yellow-pigmented and motile enterococci, isolated from the intestines of garden snails, were phenotypically close to Enterococcus casseliflavus, but they showed certain unusual biochemical characteristics. tRNA intergenic length polymorphism analysis (tDNA-PCR) divided all strains studied into two groups, in full agreement with biochemical test results. 16S rDNA sequencing, DNA base composition analysis and DNA-DNA hybridization results showed unambiguously that the enterococci studied belonged to the species Ent. casseliflavus. The representative strains of described ecovars were deposited in the Czech Collection of Microorganisms (CCM) as Ent. casseliflavus CCM 4868, 4869, 4870 and 4871. CONCLUSIONS: Enterococcus casseliflavus associated with garden snails can be subdivided into groups. SIGNIFICANCE AND IMPACT OF THE STUDY: Enterococcus casseliflavus differs from other enterococcal species in that it is typically associated with plants, soil, water and invertebrate animals. The different groups that can be found in these widely occurring bacteria are possibly source-specific ecovars, as exemplified by the Ent. casseliflavus inhabiting the intestines of snails.

Animals↗
PubMedDate not supplied

Significant role of the nitrogen recycling system through the ceca occurs in protein-depleted chickens.

This study focuses on the role of the ceca in nitrogen nutrition in chickens (Gallus domesticus). Urea is a very good nitrogen tracer for these studies. Little urea is synthesized by chickens due to the absence of carbamyl phosphate synthetase, an essential enzyme initiating the urea cycle. Urea is utilized by chickens when crystalline amino acid diets low in nonessential nitrogen or diets containing low concentrations of intact protein are fed, and most ureolytic activity is found in the ceca. Dietary urea was absorbed intact from the upper intestine of the chicken. The absorbed urea was excreted into ureteral urine that refluxed from the cloaca into the colon and ceca where urea was degraded to ammonia. Presumably the ammonia was incorporated into amino acids by cecal microorganisms and some urea, amino acids and proteins were absorbed from the ceca. These were utilized by the chickens. A beneficial role of ceca in the nitrogen metabolism in the chicken is, therefore, conservation of urinary nitrogen in protein-depleted chickens.

Absorption↗
PubMed2001

Parasites and pathologic conditions of the cockle Cerastoderma edule populations of the coast of Galicia (NW Spain).

A survey of pathological conditions affecting cockle populations of the most economically important natural beds of Galician estuaries in NW Spain was performed. Samples of 30 adult cockles were collected from each of 34 natural beds in the spring of 1999 and processed by histological techniques. Disseminated neoplasia were seen in samples from most of the natural beds, in some cases with a high prevalence. The gregarine Nematopsis sp., larval trematode stages, and branchial extracellular large cysts enclosing bacteria-like microorganisms were the most prevalent parasites. Paravortex cardii, intracellular colonies of rickettsiae-like organisms in digestive and gill epithelium, Pseudoklossia sp. coccidians, Trichodina sp., and other ciliates were frequently seen in the samples. Copepods in gills and intestine and unidentified gregarines in intestine epithelia and surrounding connective tissue were less prevalent and were observed in samples of some natural beds. Large foci of heavy hemocytic infiltration were detected in a few sites only. Cysts of Steinhausia sp. and plasmodia and spores of a haplosporidian were seen in cockles from two localities. Inflammation was frequently observed in the samples. Some of the parasites and pathological conditions could be associated with mortality.

Animal Diseases↗
PubMed1999

Dietary modulation of the human gut microflora using the prebiotics oligofructose and inulin.

Although largely unproven in humans, better resistance to pathogens, reduction in blood lipids, antitumor properties, hormonal regulation and immune stimulation may all be possible through gut microflora manipulation. One approach advocates the oral intake of live microorganisms (probiotics). Although the probiotic approach has been extensively used and advocated, survivability/viability after ingestion is difficult to guarantee and almost impossible to prove. The prebiotic concept dictates that non viable dietary components fortify certain components of the intestinal flora (e.g., bifidobacteria, lactobacilli). This concept has the advantage that survival of the ingested ingredient through the upper gastrointestinal tract is not a prerequisite because it is indigenous bacterial genera that are targeted. The feeding of oligofructose and inulin to human volunteers alters the gut flora composition in favor of bifidobacteria, a purportedly beneficial genus. Future human studies that exploit the use of modern molecular-based detection methods for bacteria will determine the efficacy of prebiotics. It may be possible to address prophylactically certain gastrointestinal complaints through the selective targeting of gut bacteria.

Animals↗
PubMed1983

[The nature of an inflammatory reaction as dependent on the etiology of infection and some peculiarities of the macroorganism].

The paper summarizes long-term studies on infectious pathology. On the example of the involvements of respiratory organs, the intestinal tract, and the central nervous system caused by viruses, bacteria, mycoplasma, fungi, and Protozoa, differences in the structural changes of the internal organs due to particular properties of the causative agents are analysed. These changes have been shown to be the greatest when the causative agents belong to different types and classes. The influence of host factors, first of all the immune status, on the course of infectious diseases is discussed. Changes occurring in the macro- and microorganism in the course of the infectious disease are considered. Not only local but also systemic defence mechanisms have been shown to be disturbed during infection which facilitates the occurrence of diseases of other etiologies and leads to increased incidence of combined infections.

Encephalitis↗
PubMedDate not supplied

[Detection rate of enterotoxigenic Staphylococcus aureus isolated from children with intestinal disbacteriosis].

Detection rate of enterotoxigenic Staphylococcus aureus isolated from faeces of 62 children aged from 3 months old to 7 years old with intestinal dysbacteriosis was studied by indirect hemagglutination assay and enzume immunoassay. It was shown that strains of S.aureus producing staphylococcal enterotoxin A (SEA) are prevailed (40.3%) in children with disturbances of intestinal microflora while staphylococcal enterotoxin B (SEB)-producing strains were detected in 20.9% of children. Amount of produced enterotoxin varied for SEA from 125 ng/ml to 2000 ng/ml and for SEB--from 125 ng/ml to 250 ng/ml. Inverse dependence of detection rate of enterotoxin-producing strains in faeces on age of children was established. The most number of enterotoxigenic strains of S.aureus was detected in infants. These data point to expediency of determination of enterotoxin-producing ability of S. aureus strains isolated from children with dysbacteriosis as measure of danger of this microorganism for children's health and indication for adequate actions for its elimination.

Age Factors↗
PubMed2000

Life at the oxic-anoxic interface: microbial activities and adaptations.

Molecular oxygen is one of the most important reactants in biogeochemical cycles. Due to its low solubility in water, the consumption of oxygen leads to the development of oxic-anoxic interfaces, which separate aerobic from anaerobic processes in virtually all environments, ranging in scale from oceanic sediments to the fecal pellets of a small soil invertebrate. Three case studies were selected to illustrate the basic situation and the specific characteristics of oxic-anoxic interfaces: sediments, the rhizosphere of aquatic plants, and the intestinal tract of insects. Each system is governed by the same general principles, but striking differences arise from, e.g., the nature of the major microbial activities and the mechanisms controlling metabolite fluxes. Also scale and dimensional differences as well as the consequences of temporal fluctuations are of fundamental importance. Recent developments in microbial ecology, which often combine traditional and modern approaches, have significantly furthered our understanding of the specific microniches and the metabolic and behavioral adaptations of microorganisms to life at the oxic-anoxic interface. New concepts help to define the targets of future studies: the spatial organization of microbial populations, their microenvironments and in situ activities, and the functional interactions within structured microbial communities.

Adaptation, Physiological↗
PubMed2006

Influence of the diet components on the symbiotic microorganisms community in hindgut of Coptotermes formosanus Shiraki.

Artificial diet was developed for rearing of lower termites (workers) Coptotermes formosanus. C. formosanus was fed with either wood powder of Japanese red pine, cellulose, cellobiose, or glucose for 30 days. The effect of carbon sources in the diet on the structure and function of the symbiotic intestinal microbial community and on the physiological activity of C. formosanus was studied. Three symbiont protozoa, Pseudotrichonympha grassi, Holomastigotoides hartmanni, and Spirotrichonympha leidyi, were found in the hindgut of C. formosanus that fed on the diets containing carbon sources with high molecular weight (MW). However, when artificial diets containing carbohydrate with low MW were used, both P. grassi and H. hartmanni disappeared, and only few S. leidyi were alive. This suggested that both P. grassi and H. hartmanni play important roles in the digestion and utilization of carbohydrate with high MW. The denaturing gradient gel electrophoresis analysis of bacterial community in the hindgut of termites showed that the similarity between intestinal bacteria community in termites fed with diets containing high-MW carbon sources and those with low MW was only about 40%. It was apparent that changes in diets resulted to changes in intestinal microbial community, and this in turn affected cellulase activity in C. formosanus.

Animals↗
PubMed1993

Differential expression of lectin-binding sites defines mouse intestinal M-cells.

We investigated the binding of four lectins to the follicle-associated epithelium (FAE) overlying fixed mouse small intestinal Peyer's patches to identify M-cell-specific surface markers. Wheat germ agglutinin and peanut agglutinin displayed heterogeneous staining patterns, binding most avidly to the intestine goblet cells. In contrast, the lectins Ulex europaeus 1 (UEA 1) and Psophocarpus tetragonolobus (winged bean; WBA) were almost exclusively M-cell specific. When confocal laser scanning images of tissues stained with fluorescein isothiocyanate (FITC)-conjugated UEA1 or WBA were compared with the appearance of the same tissues under the scanning electron microscope (SEM), UEA1 strongly stained 97.2% (106/109) of M-cells, 0.6% (3/516) enterocytes, and 0% (0/28) goblet cells, whereas WBA stained 100% (83/83) M-cells, 1.7% (6/361) enterocytes, and 5.3% (1/19) goblet cells. The M-cell specificity of the lectin binding was further demonstrated by localization of horseradish peroxidase (HRP)-conjugated lectins under the transmission electron microscope (TEM). This is the first demonstration of carbohydrates in the glycocalyx of M-cells that are not expressed elsewhere on the FAE surface. These carbohydrates not only provide a means to identify mouse M-cells by LM but may also contribute to the occurrence of specific interactions between microorganisms and the M-cell apical membrane.

Animals↗
PubMed1980

[Cyclic 3',5'-adenosine monophosphate in macrophages, intestinal mucosa, and blood plasma of germ-free and ordinary animals].

The level of cAMP in macrophages, intestinal mucosa and blood plasma as well as its formation in intestinal mucosa of germfree animals under the effect of lipopolysaccharide E. coli 055 (LPS) were studied in experiments on germfree and ordinary mice and guinea-pigs. The concentration of cAMP in intestinal mucosa of ordinary guinea-pigs was 5-fold higher than in germfree animals. LPS induced an increase in cAMP level in intestinal mucosa, but this level did not reach that in ordinary animals. The levels of cAMP in blood plasma of germfree guinea-pigs in macrophages of germfree mice increased 2-fold and 4-fold, respectively, 30 minutes following the treatment with LPS. The increased level of cAMP was accompanied by its intensive secretion into the exocellular medium. Macrophages of ordinary animals had a moderate output of cAMP. A conclusion is made about the relationship between cAMP formation and microbial contamination of the microorganism as well as about an important role of the cyclic nucleotide in the mechanism of nonspecific resistance and homeostatic reactions of the body to microbial exposure.

Animals↗
PubMed2003

Adaptation to environmental pH in Candida albicans and its relation to pathogenesis.

For microorganisms that grow over a wide range of extracellular pH, systems must have evolved to sense and respond appropriately. The human opportunistic pathogen Candida albicans colonizes and infects anatomical sites of diverse pH, including the oral and gastro-intestinal tracts and the vaginal cavity. The ability to sense and respond to neutral-alkaline environments is governed by signal transduction pathways, one of which culminates in the activation of the transcription factor, Rim101p. The RIM101/pacC pathway, which governs pH responses and differentiation, has been the focus of study in both Saccharomyces cerevisiae and Aspergillus nidulans. This pathway has been identified in C. albicans and governs pH responses, dimorphism, and pathogenesis. Although C. albicans and S. cerevisiae are related fungi, it is becoming apparent that there are unique aspects of the pH response and the role the RIM101 pathway plays in this response in C. albicans.

Adaptation, Biological↗