<Emphasis Type="Italic">Helicobacter pylori</Emphasis> and <Emphasis Type="Italic">cagA</Emphasis> and <Emphasis Type="Italic">vacA</Emphasis> gene status in children from Brazil with chronic gastritis

Helicobacter pylori has been shown to be strongly associated with chronic gastritis, gastric and duodenal ulceration, and is a risk factor for gastric carcinoma. Histology, urease, culture, and polymerase chain reaction have been employed as for H. pylori diagnostic methods, pre and post treatment or during follow-up of dyspeptic adult individuals referred for endoscopy. In order to obtain a more-sensitive and specific method for H. pylori detection, we evaluated gastric body and antrum biopsies of 134 consecutive Brazilian consecutive dyspeptic children aged 1-16 years by rapid urease test, histology and polymerase chain reaction using two pairs of oligonucleotides. Our results indicated that polymerase chain reaction with Southern blotting and hybridization with specific chemiluminescent probes increased the number of positive H. pylori patients by 35%. The genotyping of H. pylori strains directly from gastric biopsy using the same nucleic acid methodology revealed that there is no association of chronic gastritis in our infant patients with vacA s1 and the presence of the cagA gene. These data suggest an initial infection of children with normal mucosa and probably others factors than vacA s1 genotype or the presence of the cagA gene are associated with the onset of gastric disease. Altogether, our results reinforce the need for using more sensitive diagnostic methods in order to understand the role of H. pylori in the genesis of gastric disease in children and its progression in adults.     

Cercarial shedding from <Emphasis Type="Italic">Galba</Emphasis><Emphasis Type="Italic">truncatula</Emphasis> infected with <Emphasis Type="Italic">Fasciola</Emphasis><Emphasis Type="Italic">gigantica</Emphasis> of distinct geographic origins

Galba truncatula snails were experimentally infected with either of two different isolates of Fasciola gigantica, originating from Egypt or China, to determine the influence of these isolates on the characteristics of snail infections. The survival rates of G. truncatula on day 30 post-exposure were 90.0% and 60.2% in the Egyptian and Chinese groups, respectively. The frequency of cercaria-shedding snails within the Egyptian group was 79.8%, whereas in the Chinese group it was 22.4%. The parasite origin had a significant effect on the durations of the prepatent and patent periods. The mean number of cercariae shed from the Egyptian group was significantly greater than that shed from the Chinese group (a mean of 275.5 per cercaria-shedding snail compared with 29.0). These results could be explained by the fact that G. truncatula might be a natural intermediate host for F. gigantica in Egypt, and the greater adaptability of the Egyptian miracidia of F. gigantica to unusual snail hosts. These results demonstrate the influence of the geographic origin of the parasite on the success of trematodes infecting snails.     

Cysteine proteinases from promastigotes of <Emphasis Type="Italic">Leishmania</Emphasis> (<Emphasis Type="Italic">Viannia</Emphasis>) <Emphasis Type="Italic">braziliensis</Emphasis>

Leishmania (Viannia) braziliensis is the major causative agent of American tegumentary leishmaniasis, a disease that has a wide geographical distribution and is a severe public health problem. The cysteine proteinase B (CPB) from Leishmania spp. represents an important virulence factor. In this study, we characterized and localized cysteine proteinases in L. (V.) braziliensis promastigotes. By a combination of triton X-114 extraction, concanavalin A-affinity, and ion exchange chromatographies, we obtained an enriched fraction of hydrophobic proteins rich in mannose residues. This fraction contained two proteinases of 63 and 43 kDa, which were recognized by a CPB antiserum, and were partially sensitive to E-64 in enzymatic assays with the peptide Glu-Phe-Leu. In confocal microscopy, the CPB homologues localized in the peripheral region of the parasite. This data together with direct agglutination and flow cytometry assays suggest a surface localization of the CPB homologues. The incubation of intact promastigotes with phospholipase C reduced the number of CPB-positive cells, while anti-cross-reacting determinant and anti-CPB antisera recognized two polypeptides (63 and 43 kDa) derived from phospholipase C treatment, suggesting that some CPB isoforms may be glycosylphosphatidylinositol-anchored. Collectively, our results suggest the presence of CPB homologues in L. braziliensis surface and highlight the need for further studies on L. braziliensis cysteine proteinases, which require enrichment methods for enzymatic detection.     

Synteny between <Emphasis Type="Italic">Brachypodium distachyon</Emphasis> and <Emphasis Type="Italic">Hordeum vulgare</Emphasis> as revealed by FISH

We investigated by fluorescence in situ hybridization (FISH) the synteny between Brachypodium distachyon with a small genome (1C = 320 Mb) and barley with a large genome (1C = 5,100 Mb) at the chromosome level. Reciprocal genomic in situ hybridization (GISH) between B. distachyon and barley labeled mainly 45S ribosomal DNA loci, indicating that most high copy DNA is weakly conserved between both grasses. Of 13 BAC clones with inserts from different B. distachyon chromosomes, only two belonging to chromosome 1 yielded hybridization signals on a barley metaphase chromosome (on 7HS and 7HL, respectively), confirming synteny between both chromosomes. FISH experiments to characterize the synteny of single-copy loci were performed. Two of four Brachypodium sylvaticum BACs spanning a 223-kb interval homologous to the region of barley that harbors a gibberellic-acid-insensitive semi-dwarfing gene, sdw3, hybridized specifically to a central position of B. distachyon chromosome 1 short arm but not to the homologous region of the barley genome. Repeat-free sequences PCR amplified from four non-overlapping barley BACs linked to the core of Sdw3 region yielded signals at distinct positions in the middle of barley chromosome arm 2HS. Together, these results (1) confirmed the synteny between B. distachyon chromosome 1 and barley chromosomes 2H and 7H at the cytological level, (2) indicated mid-arm position for the Sdw3 locus genetically mapped at the centromere of barley chromosome 2H, and (3) proved that the sdw3 core interval of <100 kb in B. distachyon corresponds to a megabase-sized syntenic region in barley.     

Redescription of <Emphasis Type="Italic">Lemuricola</Emphasis> (<Emphasis Type="Italic">Madoxyuris</Emphasis>) <Emphasis Type="Italic">bauchoti</Emphasis> (Nematoda,Oxyuridae) from <Emphasis Type="Italic">Lemur catta</Emphasis> in Madagascar

Lemuricola (Madoxyuris) bauchoti Chabaud, Brygoo et Petter, 1965 is redescribed from material collected from the ring-tailed lemur, Lemur catta, from the Beza Mahafaly Special Reserve in Madagascar using the scanning electron microscope. This is a new host record and the first oxyurid reported from the ring-tailed lemur. Previously, records of each species of the subgenus Madoxyuris have been restricted to a single host species, but the close relationship between these nematodes and their Strepsirrhini hosts will only be proven when additional records fill in the gaps in their distribution.     

Large-scale association analysis of <Emphasis Type="Italic">TNF</Emphasis>/<Emphasis Type="Italic">LTA</Emphasis> gene region polymorphisms in type 2 diabetes

Background  

The TNF/LTA locus has been a long-standing T2D candidate gene. Several studies have examined association of TNF/LTA SNPs with T2D but the majority have been small-scale and produced no convincing evidence of association. The purpose of this study is to examine T2D association of tag SNPs in the TNF/LTA region capturing the majority of common variation in a large-scale sample set of UK/Irish origin.     

Functional polymorphisms in <Emphasis Type="Italic">XRCC</Emphasis>-<Emphasis Type="Italic">1</Emphasis> and <Emphasis Type="Italic">APE</Emphasis>-<Emphasis Type="Italic">1</Emphasis> contribute to increased apoptosis and risk of ulcerative colitis

Objective  

The present study was designed to investigate the role of X-ray cross-complementing group 1 (XRCC1) and apurinic/apyrimidinic endonuclease 1 (APE1) polymorphisms in apoptosis and the risk of ulcerative colitis (UC).     

Selective activity of extracts of <Emphasis Type="Italic">Margaritaria discoidea</Emphasis> and <Emphasis Type="Italic">Homalium africanum</Emphasis> on <Emphasis Type="Italic">Onchocerca ochengi</Emphasis>

Background  

The current treatment of onchocerciasis relies on the use of ivermectin which is only microfilaricidal and for which resistant parasite strains of veterinary importance are increasingly being detected. In the search for novel filaricides and alternative medicines, we investigated the selective activity of crude extracts of Margaritaria discoidea and Homalium africanum on Onchocerca ochengi, a model parasite for O. volvulus. These plants are used to treat the disease in North West Cameroon.     

Comparison of 18S ribosomal RNA gene sequences of <Emphasis Type="Italic">Eurytrema coelmaticum</Emphasis> and <Emphasis Type="Italic">Eurytrema pancreaticum</Emphasis>

The partial 18S rRNA sequences of E. coelmaticum and E. pancreaticum were amplified using conserved primers and an evolutionary tree was constructed using Neighbor-Joining. The percent identity of Eurytrema species with other Dicrocoeliidae varied from 97.5 to 98.2, while the percent identity between the two Eurytrema species was up to 99.3. The tree showed that E. coelmaticum and E. pancreaticum were not situated in the same position, and they formed one cluster with L. collurioni. These results support a confirmation with molecular data that E. coelomaticum and E. pancreaticum are different species which apparently were not seriously questioned in the past.     

<Emphasis Type="Italic">P</Emphasis>. <Emphasis Type="Italic">aeruginosa</Emphasis> Biofilms in CF Infection

Pseudomonas aeruginosa is an opportunistic pathogen of immunocompromised hosts. In cystic fibrosis (CF), P. aeruginosa causes acute and chronic lung infections that result in significant morbidity and mortality. P. aeruginosa possesses several traits that contribute to its ability to colonize and persist in acute and chronic infections. These include high resistance to antimicrobials, ability to form biofilms, plethora of virulence products, and metabolic versatility. In P. aeruginosa, a cell-to-cell communication process termed quorum sensing (QS) regulates many of these factors that contribute to its pathogenesis. Recent evidence suggests that the CF lung environment presents a specialized niche for P. aeruginosa. The relationship of P. aeruginosa QS, biofilm formation, and the CF lung environment is discussed.     

Use of <Emphasis Type="Italic">MET3</Emphasis> promoters for regulated gene expression in <Emphasis Type="Italic">Ashbya gossypii</Emphasis>

A central tool for gene function analysis is the construction mutant strains. This can be done conveniently in A. gossypii using PCR-based tools. The deletion of essential genes can be performed since initial transformants are sheltered in a heterokaryotic mycelium, which contains nuclei with both wild type and mutant alleles. The analysis of mutant phenotypes in A. gossypii is regularly started by germinating spores, which contain only one nucleus. Thus, selection can be used to identify mutant germ cells and germlings. However, such an analysis yields only mutant mycelia if the deleted gene is not essential. We describe the use of the regulatable Saccharomyces cerevisiae and A. gossypii MET3 promoters as novel tools to regulate gene expression in A. gossypii. Conditional expression was tested using GFP and lacZ-reporter genes. Regulation of MET3 promoters was found to be dependent on methionine but not on cysteine and down-regulation to about 1/10 of the initial expression levels was achieved. We used the A. gossypii WAL1 and CYK1 genes as models to demonstrate that MET3 promoters could regulate the expression of these genes and reveal their mutant phenotypes depending on the presence or absence of methionine. Finally, we show that the AgMET3 promoter contains two Cpf1-binding sites and that AgCPF1 can complement the S. cerevisiae cpf1 methionine auxotrophy.     

Concurrent <Emphasis Type="Italic">M. tuberculosis</Emphasis>, <Emphasis Type="Italic">Klebsiella pneumoniae</Emphasis>, and <Emphasis Type="Italic">Candida albicans</Emphasis> infection in liver metastasis of bowel carcinoma

We describe the case of a 62-year-old patient with fever and abdominal pain of the right upper quadrant with a known history of adenocarcinoma of the colon and presence of hepatic metastases. One of the liver lesions underwent aspiration, and pus was sent for microbiological testing. Cultures of the pus were positive for Klebsiella pneumoniae and Candida albicans and polymerase chain reaction for Mycobacterium tuberculosis was concurrently positive; the patient received treatment for all three pathogens and improved clinically. One may consider searching not only for the usual pathogens of liver abscesses (gram-negative bacteria, anaerobic bacteria and gram-positive bacteria), but in special cases might consider pursuing a more detailed search for coexistence of fungi and mycobacteria in patients with cancer.     

Evaluation of the BactiCard <Emphasis Type="Italic">Neisseria</Emphasis> for Identification of Pathogenic <Emphasis Type="Italic">Neisseria</Emphasis> Species and <Emphasis Type="Italic">Moraxella catarrhalis</Emphasis>

The BactiCard Neisseria (Remel, USA) is a chromogenic enzyme substrate system for identifying Neisseria gonorrhoeae, Neisseria meningitidis, Neisseria lactamica, and Moraxella catarrhalis. The identification system consists of a card with four test circles impregnated with chromogenic substrates for indoxyl butyrate esterase (IB), prolyl aminopeptidase (PRO), γ-glutamyl aminopeptidase (GLUT), and ?-galactosidase (BGAL). These substrates permit the identification of Moraxella catarrhalis, Neisseria gonorrhoeae, Neisseria meningitidis, and Neisseria lactamica, respectively. After hydration of the circles with buffer, colonies from growth on selective media or a subculture are applied to the four circles. IB and BGAL reactions are read for a blue-green color after 2 and 15 min, respectively. PRO and GLUT reactions are read at 15 min for a red color after addition of a developer reagent. Identifications obtained with the BactiCard Neisseria were compared with those obtained using conventional procedures for 558 isolates in a blinded fashion. The BactiCard Neisseria identified 100% of 254 Neisseria gonorrhoeae, 100% of 125 Neisseria meningitidis, 53 (98.2%) of 54 Neisseria lactamica, and 123 (98.4%) of 125 Moraxella catarrhalis isolates. The BactiCard Neisseria is an accurate and rapid system for identification of these microorganisms in the clinical laboratory. Electronic Publication