Immunodetection of Furcraea Necrotic Streak Virus-FNSV in fique plants (Furcraea macrophylla Baker) using a polyclonal antibody IgY produced in chicken egg yolk.

The necrotic streak of the fique (Furcraea spp.) or "Macana" disease is considered the most limiting disease for this crop in Colombia, whose causal agent is the Furcraea Necrotic Streak Virus - FNSV (RNA+). Currently, there are no strategies to control the disease, being necessary to develop methods for detection of this pathogen in the planting material before being taken to the field. In this study, polyclonal antibodies produced in egg yolk (IgY) were produced and assesses for detection FNSV. Two immunoenzymatic methodologies were standardized: dot blot immunobinding assay (DBIA) and enzyme-linked immunosorbent assay (ELISA), determining their specificity and sensitivity. The detection limit by DBIA corresponded to 8 µg/mL of purified virus suspension using 10 µg/mL of primary antibody. In the ELISA test, the primary antibody concentration of 3 µg/mL (1:800 dilution) detected the antigen at concentrations between 10 and 70 µg/mL. The polyclonal antibody anti-FNSV IgY allowed the detection of FNSV in samples of purified virus and extracts of roots and leaves of fique plants with symptoms of "Macana" disease and did not produce any signal with the control samples. Results showed the potential of using egg yolk IgY in immunological tests for the detection of FNSV in fique plants.

Helicobacter pylori eradication does not cause reflux oesophagitis in functional dyspeptic patients: a randomized, investigator-blinded, placebo-controlled trial.

BACKGROUND: The protective role of Helicobacter pylori in gastro-oesophageal reflux disease has been widely discussed. AIM: To assess the risk of reflux oesophagitis in patients with functional dyspepsia after treatment for H. pylori infection. METHODS: A randomized, placebo-controlled, investigator-blinded trial was carried out on 157 functional dyspeptic patients. Patients were randomized to receive lansoprazole, amoxicillin and clarithromycin (antibiotic group) or lansoprazole and identical antibiotic placebos (control group). Upper gastrointestinal endoscopy was performed at baseline, 3 and 12 months after randomization. The primary aim was to detect the presence of reflux oesophagitis. Analyses were performed on an intention-to-treat basis. RESULTS: A total of 147 patients (94%) and 133 (85%) completed 3 months and 12 months follow-up, respectively. The eradication rate of H. pylori was 90% in the antibiotic group (74 of 82) and 1% (one of 75) in the control group. At 3 months, reflux oesophagitis was diagnosed in 3.7% (three of 82) in the antibiotic group and 4% (three of 75) in the control group (P > 0.2). At 12 months, diagnosis was established in five new cases within the first group and in four within the second (P > 0.2). No difference was found in heartburn symptoms. CONCLUSIONS: H. pylori eradication does not cause reflux oesophagitis in this western population of functional dyspeptic patients.