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Intestinal Pathogens (intestinal + pathogen)

Distribution by Scientific Domains

Medical Sciences	50%

Selected Abstracts

Amoebiasis cutis: Clinical suspicion is the key to early diagnosis

AUSTRALASIAN JOURNAL OF DERMATOLOGY, Issue 1 2010
Ghanshyam K Verma
ABSTRACT Amoebiasis cutis is a rare manifestation of Entamoeba histolytica, primarily an intestinal pathogen, which occurs as a complication of amoebic dysentery. Primary cutaneous amoebiasis occurs from contamination of pre-existing wounds. A high degree of clinical suspicion and demonstration of trophozoites from lesions are important for making an early diagnosis lest these patients should suffer significant morbidity. A HIV-negative and otherwise healthy 40-year-old man presented with a well-defined, indurated, painful, progressively enlarging plaque with overlying ulcers and pus discharging sinuses involving buttocks, perianal/perineal area and part of the left thigh of 3 years' duration. A wide array of investigations was unhelpful but demonstration of Entamoeba histolytica trophozoites in wet-drop preparation from the ulcer margin was diagnostic. The trophozoites were also visualized both in H&E and periodic acid Schiff-stained histological sections. Resolution of lesion was observed 2 weeks after treatment with oral metronidazole 800 mg three times a day and wound care. [source]

Regulatory T cells and intestinal homeostasis

IMMUNOLOGICAL REVIEWS, Issue 1 2005
Janine L. Coombes
Summary:, Murine models of inflammatory bowel disease (IBD) are useful tools for the study of the pathogenesis and regulation of intestinal inflammation. Colitis can be induced in immune-deficient mice following transfer of populations of T cells or following infection with Helicobacter hepaticus and other intestinal pathogens. In these situations, colitis occurs as a result of the absence of a specialized population of regulatory cells, as transfer of CD4+CD25+ T cells prevents disease. Importantly, from a clinical perspective, CD4+CD25+ T cells can also reverse an established colitis. CD4+CD25+ T cells proliferate both in the secondary lymphoid organs and at the site of inflammation, suggesting that regulation occurs both locally and systemically. CD4+CD25+ T cells are not only capable of regulating other T cells but are also capable of suppressing components of the innate immune system. Control of colitis is dependent on the presence of the immunosuppressive cytokines interleukin-10 and transforming growth factor-,, although their roles are divergent and complex. Regulatory T cells represent one of the host's mechanisms to prevent immune pathology during chronic immune stimulation. Enhancement of regulatory T-cell activity may be useful to control autoreactive T-cell responses and inhibit harmful inflammatory diseases such as asthma and IBD. [source]

Subtractive Screening for Probiotic Properties of Lactobacillus Species from the Human Gastrointestinal Tract in the Search for New Probiotics

JOURNAL OF FOOD SCIENCE, Issue 8 2007
S. Delgado
ABSTRACT:, In the search for new probiotics, 61 Lactobacillus spp. isolates, belonging to 12 species and isolated as dominant lactic acid bacteria from the feces of healthy humans, were subjected to a subtractive system of in vitro analyses, which included desirable and undesirable traits. Twenty-four isolates were able to grow in 2% bovine bile, of which 13 grew in acidified broth at pH 3.5 in acidified cysteine-containing MRS broth. Intrinsic resistance to certain antimicrobial agents (cefoxitin, metronidazole, vancomycin) was observed in most isolates, but atypical resistances to erythromycin, clindamycin, or tetracycline were also found in 5 strains. Undesirable traits such as ,-chymotrypsin or N-acetyl-,-glucosaminidase activities were not detected, but low ,-glucuronidase and moderate ,-glucosidase activities were recorded in 2 strains. Two Lactobacillus gasseri and 2 Lactobacillus paracasei selected strains inhibited several intestinal pathogens in an agar spot test, including strains of Escherichia coli, Listeria monocytogenes, Salmonella typhimurium, and Staphylococcus aureus. They also adhered to human Caco-2 and HT-29 epithelial cells in a manner comparable to Lactobacillus rhamnosus strain GG, and were unable to degrade pig gastric mucin in a plate assay. Together, these results suggest these 4 strains to be good probiotic candidates, concluding that the subtractive screening devised in this work could be a valuable tool in large-scale surveys for probiotics. [source]

Dendritic cells in the recognition of intestinal microbiota

CELLULAR MICROBIOLOGY, Issue 4 2006
Jan Hendrik Niess
Summary Mucosal dendritic cells (DCs) constantly survey the luminal microenvironment which contains commensal microbiota and potentially harmful organisms regulating pathogen recognition and adaptive as well as innate defense activation. Distinct mechanisms are beginning to emerge by which intestinal antigen sampling and handling is achieved ensuring specificity and contributing to redundancy in pathogen detection. Distinct DC subsets are associated with these mechanisms and regulate specific innate or adaptive immune responses to help distinguish between commensal microbiota, pathogens and self antigens. Understanding DC biology in the mucosal immune system may contribute to the unraveling of infection routes of intestinal pathogens and may aid in developing novel vaccines and therapeutic strategies for the treatment of infectious and inflammatory diseases. [source]