Comparisons of competitive enzyme-linked immunosorbent assay and one step RT-PCR tests for the detection of Bluetongue virus in south west of Iran

Bluetongue is a noncontagious, arthropod-borne viral disease of both domestic and wild ruminants. Bluetongue virus (BTV) is the type of species of the genus Orbivirus within the family Reoviridae. BTV is endemic in some areas with cattle and wild ruminants serving as reservoirs for the virus. Clinical symptoms are often seen in sheep. There are several methods for the detection of Bluetongue virus, among them the molecular technique like RT-PCR is considered as the most sensitive and reliable one. The aim of this study was to comprise competitive enzyme-linked immunosorbent assay (C-ELISA) with one step RT-PCR test for the detection of BTV in sheep. A total of 770 blood samples were obtained from sheep (265 serum positive samples and 505 serum negative samples in C-ELISA). According to our data, out of the 265 serum positive samples in ELISA test, 234 were positive in RT-PCR assay whereas all serum negative samples were negative in RT-PCR experiment. According to the results, the PCR assay was more sensitive and reliable than ELISA technique for the diagnosis of Bluetongue virus.Key words: Bluetongue virus, C-ELISA, RT- PCR, Sheep, Iran

PP-005 Clarithromycin resistance assessment in Helicobacter pylori isolates by using 23S rRNA gene molecular markers

Background: H. pylori is a relatively fastidious and microaerophilic microorganism and therefore standard phenotypic susceptibility tests, even in the hands of experts, are slow and can take at least 10 14 days. Molecular based diagnostic assays by using molecular markers for resistance detection offer an attractive alternative approach to obtain susceptibilities to antibiotics with greater accuracy and speed, and the possibility of a same day result. The aim of this study is the assessment of clarithromycin resistance by using molecular markers. Methods: This cross-sectional descriptive study was performed on 200 gastric biopsy specimens which were obtained from patients undergoing upper gastrointestinal tract endoscopy in Hajar hospital of Shahrekord, by using TaqMan real-time PCR. Initially, H. pylori strains were identified by RUT and PCR. Then, by this regard that accumulation of mutations associated with resistance to clarithromycin were in the region between nucleotides 2142 2144 of 23S rRNA gene, the first probe was designed to be able the distinguish between sensitive and resistant strains. Finally four probes were designed that each be able to identify only one mutation associated with a particular level of clarithromycin resistance. Results: Out of 200 samples, 164 (82%) were H. pylori positive. Overall, clarithromycin susceptible strains were detected in 105 (64.02%) patients and clarithromycin resistance were detected in 59 (35.98%) which were identified as 4 (2.44%) A2144G, 26 (15.85%) A2143G, 15 (9.15%) A2143C and 20 (12.19%) A2142G point mutations. Purely resistant strains were detected in 38 (23.17%), while heteroresistant were found in the remaining 16 (9.76%) cases. Genotype of 5 (8.47%) strains was not detected. This data was confirmed by PCR-RFLP technique. Conclusion: Results showed that Real-time PCR assay in combination with molecular markers has high accuracy to simultaneously identify H. pylori and clarithromycin resistance types directly in gastric biopsy specimens in short time