cagE as a biomarker of the pathogenicity of Helicobacter pylori

IntroductionHelicobacter pylori infection is associated with gastro-duodenal diseases. Genes related to pathogenicity have been described for H. pylori and some of them appear to be associated with more severe clinical outcomes of the infection. The present study investigates the role of cagE as a pathogenicity biomarker of H. pylori compare it to cagA, vacA, iceA and babA2 genes and correlate with endoscopic diagnoses.MethodsWere collected biopsy samples of 144 dyspeptic patients at the Hospital of the Federal University of Rio Grande, Rio Grande do Sul, Brazil. After collection, the samples were sent for histological examination, DNA extraction and detection of all putative pathogenicity genes by PCR.ResultsOf the 144 patients undergoing endoscopy, 57 (39.6%) presented H. pylori by histological examination and PCR by detection of the ureA gene. Based on the endoscopic diagnoses, 45.6% (26/57) of the patients had erosive gastritis, while 54.4% (31/57) had enanthematous gastritis. The genes cagA, cagE, vacAs1/m1, vacAs1/m2 and iceA1 were related to erosive gastritis, while the genes vacAs2/m2, iceA2 and babA2 were associated to enanthematous gastritis. We found a statistically significant association between the presence of cagE and the endoscopic diagnosis. However, we detect no statistically significant association between the endoscopic diagnosis and the presence of cagA, vacA, iceA and babA2, although a biological association has been suggested.ConclusionsThus, cagE could be a risk biomarker for gastric lesions and may contribute to a better evaluation of the H. pylori pathogenic potential and to the prognosis of infection evolution in the gastric mucosa.

Impact of fish cage-culture on the community structure of zooplankton in a tropical reservoir

We investigated the impact of fish cage culture on the zooplankton community structure in a tropical reservoir. We hypothesized that community abundance is greater near cages and increases over time due to the increase in food availability. Samplings were performed near, upstream and downstream from net cages, and before and after net cage installation. The abundance of zooplankton increased 15 days after the experiment was set up, followed by a reduction and finally increased. Rotifer abundance showed significant differences among sites (p<0.05) and sampling periods (p<0.001). Significant differences were also observed in total zooplankton and cladoceran abundance (p<0.001). The spatial and temporal variation of the physical and chemical variables were indirectly correlated with the structure and dynamic of the zooplankton community, as they indicated the primary production in the environment. Our hypothesis was rejected, since the zooplankton was abundant at the reference site. Only rotifers showed higher abundance near cages, due to the influence of food availability. Community dynamics during the experiment was also correlated to food availability. Our results suggest an impact of fish farming on the zooplankton community.

Large indoor cage study of the suppression of stable Aedes aegypti populations by the release of thiotepa-sterilised males

The sterile insect technique (SIT) is a promising pest control method in terms of efficacy and environmental compatibility. In this study, we determined the efficacy of thiotepa-sterilised males in reducing the target Aedes aegypti populations. Treated male pupae were released weekly into large laboratory cages at a constant ratio of either 5:1 or 2:1 sterile-to-fertile males. A two-to-one release ratio reduced the hatch rate of eggs laid in the cage by approximately a third and reduced the adult catch rate by approximately a quarter, but a 5:1 release drove the population to elimination after 15 weeks of release. These results indicate that thiotepa exposure is an effective means of sterilising Ae. aegypti and males thus treated are able to reduce the reproductive capacity of a stable population under laboratory conditions. Further testing of the method in semi-field enclosures is required to evaluate the mating competitiveness of sterile males when exposed to natural environmental conditions. If proven effective, SIT using thiotepa-sterilised males may be incorporated into an integrated programme of vector control to combat dengue in Cuba.

Morphometric and allometric relations of cage-reared Iguaçu surubim

The objective of this work was to evaluate the morphometric and allometric relations of Iguaçu surubim (Steindachneridion melanodermatum) cultivated in net cages. One hundred and twenty specimens were cultivated at a density of 50 fish per square meter in three 6 m³ net cages. Fish were fed three times a day with commercial feed. Thirty fish were evaluated at 60, 120, 180, and 360 days of cultivation as to the variables: total body, head, clean trunk, viscera, skin, and fin weight; total, standard, and head length; and head and body height. The Iguaçu surubim shows later development of the clean trunk and early development of the other body parts.