Isolation and characterization of a Helicobacter sp. from the gastric mucosa of dolphins, Lagenorhynchus acutus and Delphinus delphis

Gastric ulcerations in dolphins have been reported for decades. Some of these lesions were associated with parasitic infections. However, cases of nonparasitic gastric ulcers with no clearly defined etiology also have been reported in wild and captive dolphins. Considerable speculation exists as to whether dolphins have Helicobacter-associated gastritis and peptic ulcer disease. The stomachs of seven stranded Atlantic white-sided dolphins, Lagenorhynchus acutus, and 1 common dolphin, Delphinus delphis, were assessed for the presence of Helicobacter species. Novel Helicobacter species were identified by culture in the gastric mucosa of two of the eight dolphins studied and by PCR in seven of the eight dolphins. The gram-negative organisms were urease, catalase, and oxidase positive. Spiral to fusiform bacteria were detected in gastric mucosa by Warthin Starry staining. Histopathology revealed mild to moderate diffuse lymphoplasmacytic gastritis within the superficial mucosa of the main stomach. The pyloric stomach was less inflamed, and bacteria did not extend deep into the glands. The lesions parallel those observed in Helicobacter pylori-infected humans. Bacteria from two dolphins classified by 16S rRNA analysis clustered with gastric helicobacters and represent a novel Helicobacter sp. most closely related to H. pylori. These findings suggest that a novel Helicobacter sp. may play a role in the etiopathogenesis of gastritis and gastric ulcers in dolphins. To our knowledge this represents the first isolation and characterization of a novel Helicobacter sp. from a marine mammal and emphasizes the wide host distribution and pathogenic potential of this increasingly important genus.     

A novel enterohepatic Helicobacter species 'Helicobacter mastomyrinus' isolated from the liver and intestine of rodents

BACKGROUND: A number of novel Helicobacter species have been isolated from both animals and humans. Many of these helicobacters colonize the lower gastrointestinal tract and hepatobiliary tract and are associated with diseases. METHODS: A spiral-shaped bacterium, with bipolar single-sheathed flagella, was isolated from the liver and cecum of mastomys (the African rodent, Mastomys natalenis), from the feces and ceca of normal mice, and also from the cecum of a mouse with proctitis. 16S ribosomal RNA gene sequence analysis, restriction fragment length polymorphism (RFLP) and fluorophore-enhanced repetitive element polymerase chain reaction (FERP or rep-PCR) analysis were used to classify the organism. RESULTS: The bacterium grew at 37 and 42 degrees C under microaerobic conditions, rapidly hydrolyzed urea, and was catalase and oxidase positive. It did not reduce nitrate to nitrite, and was resistant to cephalothin and nalidixic acid. Like many other enterohepatic Helicobacter species, this organism expressed cytolethal distending toxin and causes cell distention. CONCLUSIONS: The organism was classified as a novel Helicobacter species for which we propose the name 'Helicobacter mastomyrinus'. Although 'H. mastomyrinus', like Helicobacter hepaticus and Helicobacter bilis, colonizes the liver of rodents, the pathogenic potential of this novel helicobacter is unknown.     

Isolation and characterization of a Chryseobacterium strain from the gut of the American cockroach, Periplaneta americana

A 16S rDNA sequence cloned directly from whole-gut microbiota of the American cockroach, Periplaneta americana, indicated the presence of a member of the Bacteroides/Flavobacterium group most closely related to the genus Flavobacterium. In an attempt to confirm this finding, we isolated a yellow-pigmented bacterium (strain FR2) from the hindgut of this insect. Strain FR2 was phylogentically and phenotypically most similar to species of Flavobacterium and related bacteria, namely Chryseobacterium indologenes. Fifty-four other yellow-pigmented bacteria isolated during a 1-year study shared the salient phenotypic characteristics of Chryseobacterium spp., and thus were considered the same phenotype. This phenotype's abundance was related to the fiber content of the insect diet, being consistently detected only in cockroaches fed a high-fiber diet (30% crude fiber by weight). The highest population density was in the hindgut, ranging from 2 x 10(6) to 1.2 x 10(7) colony forming units ml(-1) during a 1-year period. The nature of the symbiosis between the FR2 phenotype and P. americana is discussed.     

Fnr (EtrA) acts as a fine-tuning regulator of anaerobic metabolism in <Emphasis Type="Italic">Shewanella oneidensis</Emphasis>MR-1

Background  

EtrA in Shewanella oneidensis MR-1, a model organism for study of adaptation to varied redox niches, shares 73.6% and 50.8% amino acid sequence identity with the oxygen-sensing regulators Fnr in E. coli and Anr in Pseudomonas aeruginosa, respectively; however, its regulatory role of anaerobic metabolism in Shewanella spp. is complex and not well understood.     

Alternative communication systems for people with severe motor disabilities: a survey

We have now sufficient evidence that using electrical biosignals in the field of Alternative and Augmented Communication is feasible. Additionally, they are particularly suitable in the case of people with severe motor impairment, e.g. people with high-level spinal cord injury or with locked-up syndrome. Developing solutions for them implies that we find ways to use sensors that fit the user's needs and limitations, which in turn impacts the specifications of the system translating the user's intentions into commands. After devising solutions for a given user or profile, the system should be evaluated with an appropriate method, allowing a comparison with other solutions. This paper submits a review of the way three bioelectrical signals - electromyographic, electrooculographic and electroencephalographic - have been utilised in alternative communication with patients suffering severe motor restrictions. It also offers a comparative study of the various methods applied to measure the performance of AAC systems.     

Correlation of Aggregatibacter actinomycetemcomitans Detection with Clinical/Immunoinflammatory Profile of Localized Aggressive Periodontitis Using a 16S rRNA Microarray Method: A Cross-Sectional Study

Objective

The objective of this study was to determine whether the detection of Aggregatibacter actinomycetemcomitans (Aa) correlates with the clinical and immunoinflammatory profile of Localized Aggressive Periodontitis (LAP), as determined by by 16S rRNA gene-based microarray.

Subjects and Methods

Subgingival plaque samples from the deepest diseased site of 30 LAP patients [PD ≥ 5 mm, BoP and bone loss] were analyzed by 16S rRNA gene-based microarrays. Gingival crevicular fluid (GCF) samples were analyzed for 14 cyto/chemokines. Peripheral blood was obtained and stimulated in vitro with P.gingivalis and E.coli to evaluate inflammatory response profiles. Plasma lipopolysaccharide (LPS) levels were also measured.

Results

Aa was detected in 56% of LAP patients and was shown to be an indicator for different bacterial community structures (p<0.01). Elevated levels of pro-inflammatory cyto/chemokines were detected in LPS-stimulated blood samples in both Aa-detected and Aa-non-detected groups (p>0.05). Clinical parameters and serum LPS levels were similar between groups. However, Aa-non-detected GCF contained higher concentration of IL-8 than Aa-detected sites (p<0.05). TNFα and IL1β were elevated upon E.coli LPS stimulation of peripheral blood cells derived from patients with Aa-detected sites.

Conclusions

Our findings demonstrate that the detection of Aa in LAP affected sites, did not correlate with clinical severity of the disease at the time of sampling in this cross-sectional study, although it did associate with lower local levels of IL-8, a different subgingival bacterial profile and elevated LPS-induced levels of TNFα and IL1β.     

First report of Phytopythium vexans causing the “Avocado sadness” in Michoacan,Mexico

Mexico is the main producer, consumer and exporter of avocado in the world, being Michoacan the main producer state contributing more than 80% of the national production. There are phytopathogens that decimate the production causing the death of the tree. Root samples were collected in avocado trees that showed the characteristic symptomatology of the disease known as avocado sadness, the sampling was carried out in four of the main avocado producing towns, in the state of Michoacan, Mexico. The isolation consisted in sowing root tissue in Petri dishes with V8^®-PARPH culture medium, subsequently they were identified morphologically and for species level it was determined by molecular biology, with the PCR-ITS technique. Pathogenicity tests were performed in triplicate with avocado seedlings with more than six leaves. After 24 hours, the inoculated plants expressed decay in the apical part, after 120 hours the leaves showed yellowing and after 15 days there was a generalized wilt on the stem and leaves, re-isolating the phytopathogen Phytopythium vexans. This study confirms the first report of the oomycete P. vexans affecting avocado trees in the most important producing region of the Mexican Republic.     

The human neonatal small intestine has the potential for arginine synthesis; developmental changes in the expression of arginine-synthesizing and -catabolizing enzymes

Background  

Milk contains too little arginine for normal growth, but its precursors proline and glutamine are abundant; the small intestine of rodents and piglets produces arginine from proline during the suckling period; and parenterally fed premature human neonates frequently suffer from hypoargininemia. These findings raise the question whether the neonatal human small intestine also expresses the enzymes that enable the synthesis of arginine from proline and/or glutamine. Carbamoylphosphate synthetase (CPS), ornithine aminotransferase (OAT), argininosuccinate synthetase (ASS), arginase-1 (ARG1), arginase-2 (ARG2), and nitric-oxide synthase (NOS) were visualized by semiquantitative immunohistochemistry in 89 small-intestinal specimens.