Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0017160 (gastroenteritis)
 11,398 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Aeromonas caviae, an enteropathogen associated with gastroenteritis, displays several virulence characteristics. Studies on the kinetics of growth of A. caviae and expression of beta-haemolytic toxin revealed that A. caviae produced maximum haemolytic activity extracellularly during the stationary phase. Preliminary studies on the properties of A. caviae haemolysin suggested that divalent cations (Mg2+ and Ca2+) and thiol compounds, dithiothreitol and mercaptoethanol enhanced the haemolytic activity. Addition of L-cysteine, glutathione and EDTA reduced the haemolytic activity. The iron chelator, 2-2' bipyridyl, significantly inhibited the growth of A. caviae possibly by iron limitation, with parallel enhancement of haemolysin production compared to A. caviae grown in excess of iron. These results suggest that A. caviae produces only beta-haemolysin, which resembles the haemolysins reported for several other bacteria and the activity might be regulated by environmental factors especially iron.
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PMID:Characterisation of haemolytic activity from Aeromonas caviae. 815 3

In Nigeria, the beginning of the structural adjustment program (SAP) in 1986 marked the beginning of a considerable decrease in real income and an unparalleled increase in food prices. This economic crisis stimulated reduced food consumption, particularly that of nutritious foods, and an increase in malnutrition. For example, in Borno/Yobe States in 1987, SAP contributed to an average decrease in energy and protein intake of 27% and 33%, respectively. SAP also contributed greatly to the almost complete destruction of nutrition oriented health delivery services. Different surveys of nutritional assessment in Nigeria reveal low intakes of protein, energy, iron, calcium, zinc, thiamin, and riboflavin in almost all age groups and in both sexes. Malnutrition and related diseases (diarrhea, measles, anemia, and gastroenteritis) are the cause of most deaths in infants and young children. The underlying causes of malnutrition in Nigeria are poverty, inadequate food production, inadequate food intake, ignorance and uneven distribution of food, poor food preservation techniques, improper preparation of foods, food restrictions and taboos, and poor sanitation. Economic reforms will likely continue into the first decade of the 21st century, so Nigeria really needs sustainable remedies to alleviate malnutrition. Recommended remedial programs are more support for rural farmers through input subsidies and high producer prices, improving rural credit schemes (e.g., the People's Bank) that target the poor, distribution of vitamin A and iron supplements in rural health centers, promoting production of low cost weaning diets, and integrating nutrition education in primary health care programs and in educational curricula.
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PMID:Undernutrition in Nigeria: dimension, causes and remedies for alleviation in a changing socio-economic environment. 841 69

Evaluation of 82 cases of amoebiasis including 4 of liver abscess was done. Microscopy of 62 stool samples revealed trophozoites in 19 (30.6%) and cysts in 8 (12.9%). PVA preserved samples were stained by iron-hamatoxylin and trichrome. Twenty-nine samples (46.7%) were positive by culture on Endamoeba, NIH and Charcoal agar. Additional two culture positive cases were negative by direct microscopy. Three (75%) samples of liver abscess pus were culture positive. Of the sera screened for amoebic antibodies by ELISA, 13 (17.3%) were positive. Stool and blood of healthy controls and 25 gastroenteritis cases were similarly analysed. Of healthy controls one had a high ELISA titre.
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PMID:Evaluation of laboratory techniques for diagnosis of amoebiasis. 991 76

Salmonella typhimurium is an invasive pathogen that causes diseases ranging from mild gastroenteritis to enteric fever. During the infection process, S. typhimurium induces a number of virulence genes required to circumvent host defences and/or acquire nutrients in the host. We have used the in vivo expression technology (IVET) system to select for S. typhimurium genes that are induced after invasion of a murine cultured cell line. We have characterized a putative iron transporter in Salmonella pathogenicity island 1, termed sitABCD. The sitABCD operon is induced under iron-deficient conditions in vitro and is repressed by Fur. This locus is induced in the animal specifically after invasion of the intestinal epithelium. We show that a sit null mutant is significantly attenuated in BALB/c mice, suggesting that SitABCD plays an important role in iron acquisition in the animal.
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PMID:The putative iron transport system SitABCD encoded on SPI1 is required for full virulence of Salmonella typhimurium. 1071 95

In June 2000, the WHO warned that the level of resistance to drugs used to treat common infectious diseases is now reaching a crisis point. If world governments do not control infections better in order to slow down the development of drug resistance, entire populations could be wiped out by superbugs against which there is no efficient treatment. Development of resistance is due to both underuse and overuse of drugs, and strategies have been worked out, to slow down the development of resistance for instance by the Norwegian Ministry of Health and Social Affairs. The present article deals with an old principle, mainly developed behind the Iron Curtain, which is now attracting renewed attention in the west: the application of bacterial viruses (bacteriophages) in the fight against bacteria. According to clinical trials in Eastern Europe, mostly uncontrolled, phages have been used successfully in treatments against antibiotic-resistant bacteria, for instance in suppurative wound infections, gastroenteritis, sepsis, osteomyelitis and pneumonia. These encouraging data are supported by recent findings in well-controlled animal models demonstrating that phages can rescue animals from a variety of fatal infections. The present review discusses possible advantages and limitations of phage treatment in humans.
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PMID:[Bacteria-killing viruses, Stalinists and "superbugs"]. 1187 46

Iron-deficiency anemia is still a health problem worldwide. Iron supplementation of some foods such as milk formulas and cereals apparently has not been the solution due to bioavailability of iron. In Mexico, there is high prevalence of anemia in children to date, mainly those under 2 years of age and predominantly in the Southern part of the country. Probably the main causes are iron-deficiency anemia in pregnant women, recurrent infections, such as gastroenteritis and parasites, and the most important one undoubtedly, deficient iron intake.
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PMID:[Iron-deficiency anemia in children. A old problem not yet resolved]. 1294 96

Campylobacter jejuni, the leading cause of human gastroenteritis, expresses a ferric binding protein (cFbpA) that in many pathogenic bacteria functions to acquire iron as part of their virulence repertoire. Recombinant cFbpA is isolated with ferric iron bound from Escherichia coli. The crystal structure of cFbpA reveals unprecedented iron coordination by only five protein ligands. The histidine and one tyrosine are derived from the N-terminal domain, whereas the three remaining tyrosine ligands are from the C-terminal domain. Surprisingly, a synergistic anion present in all other characterized ferric transport proteins is not observed in the cFbpA iron-binding site, suggesting a novel role for this protein in iron uptake. Furthermore, cFbpA is shown to bind iron with high affinity similar to Neisserial FbpA and exhibits an unusual preference for ferrous iron (oxidized subsequently to the ferric form) or ferric iron chelated by oxalate. Sequence and structure analyses reveal that cFbpA is a member of a new class of ferric binding proteins that includes homologs from invasive and intracellular bacteria as well as cyanobacteria. Overall, six classes are defined based on clustering within the tree and by their putative iron coordination. The absence of a synergistic anion in the iron coordination sphere of cFbpA also suggests an alternative model of evolution for FbpA homologs involving an early iron-binding ancestor instead of a requirement for a preexisting anion-binding ancestor.
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PMID:Anion-independent iron coordination by the Campylobacter jejuni ferric binding protein. 1561 74

In pathogenic bacteria, iron acquisition is important for colonization and proliferation in the host under iron-limited conditions. The ability of Vibrio spp. to acquire iron is often critical to their virulence, causing gastroenteritis or excessive watery diarrhea in humans. In the study described here, we cloned the 2,100-bp heme utilization protein gene hupO in Vibrio fluvialis. HupO had high homology to iron-regulated outer membrane receptor proteins in Vibrio sp. and contained motifs that are common to bacterial heme receptors, including a consensus TonB box, a FRAP domain, and an NPNL domain. To characterize the hemin-binding activity of HupO, we purified the recombinant HupO protein (rHupO) from Escherichia coli by using an overexpression system. HupO was found to bind to hemin but not to hemoglobin. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting demonstrated that the 77-kDa outer membrane protein HupO of V. fluvialis was induced under iron-restricted conditions. We constructed a hupO mutant, HP1, to investigate the biochemical function of HupO in V. fluvialis. The hemolytic activity of HP1 was reduced compared to that of wild-type cells and, when exposed to hydrogen peroxide, significantly lower numbers of HP1 survived than was the case in the wild type. These results suggest that HupO is associated with virulence expression in V. fluvialis through stimulation of hemolysin production and resistance to oxidative stress. In experimentally infected mice, the 50% lethal dose value of the wild-type was lower than that of the mutant, HP1.
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PMID:Identification of an iron-regulated hemin-binding outer membrane protein, HupO, in Vibrio fluvialis: effects on hemolytic activity and the oxidative stress response. 1566 10

A characteristic feature of Helicobacterpylori infection in developing countries is early acquisition of the bacteria during childhood. Recent study has documented the frequency of transient infection in young children in particular during the first year following eradication therapy. Children living in developing countries present several risk factors for acquisition including crowding, young age, and recurrent gastroenteritis. The risk of infection increases significantly in function of the number of infected persons in a child's family. Using molecular biology techniques based on gene sequencing, we have shown that strains in different members of the same family were identical not only between parents and children but also between siblings. The relationship between chronic diarrhoea, retarded growth, iron-deficient anaemia, and Helicobacter pylori infection in children especially from developing countries remains controversial. Gram staining of biopsy smears to detect Helicobacter pylori is an efficient diagnostic method and can be a good alternative when culture is unfeasible. Respiratory testing and detection of antigens in stools are effective and appear to be well suited to diagnosis of Helicobacter pylori infection. In developing countries Helicobacter pylori is a common infectious agent warranting further study to gain insight into clinical presentation, epidemiological features, and treatment requirements including sensitivity to antibiotics
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PMID:[Helicobacter pylori infection in children of developing countries]. 1654 96

Since 1996, Vibrio parahaemolyticus serotype O3:K6 and closely related strains have been associated with an increased incidence of V. parahaemolyticus gastroenteritis worldwide, suggesting the emergence of strains with enhanced abilities to cause disease. One hypothesis for the recent emergence of V. parahaemolyticus O3:K6 and related strains is an enhanced capacity for environmental survival relative to other strains, which might result in increased human exposure to these organisms. Therefore, the objective of this study was to test the hypothesis that survival or growth characteristics of clinical V. parahaemolyticus isolates differ from those of nonclinical isolates under different environmental conditions. Twenty-six V. parahaemolyticus isolates selected to represent either clinical or food sources were monitored for either survival following exposure to high magnesium (300 mM) or growth under iron-limited conditions. Isolates in each category (clinical or food) differed widely in survival capabilities following 24 h of exposure to 300 mM Mg2+. Although 4 of 15 clinical isolates grew better at approximately 0.96 microM Fe2+ (iron-limited conditions) than at 50 microM Fe2+ (iron-rich conditions), as an entire group clinical isolates in this study were not more effective at growing under iron-limited conditions than were strains not associated with disease. Within the diverse collection of strains examined in these experiments, neither growth characteristics in low-iron environments nor survival capabilities following exposure to high magnesium concentrations were uniformly different between clinical and nonclinical V. parahaemolyticus isolates. Therefore, neither phenotypic characteristic can be used to reliably differentiate potentially pathogenic V. parahaemolyticus strains.
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PMID:Vibrio parahaemolyticus growth under low-iron conditions and survival under high-magnesium conditions. 1671 2


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