Prior infection with antigenically heterologous low pathogenic avian influenza viruses interferes with the lethality of the H5 highly pathogenic strain in domestic ducks

Low and highly pathogenic avian influenza viruses (LPAIVs and HPAIVs, respectively) have been co-circulating in poultry populations in Asian, Middle Eastern, and African countries. In our avian-flu surveillance in Vietnamese domestic ducks, viral genes of LPAIV and HPAIV have been frequently detected in the same individual. To assess the influence of LPAIV on the pathogenicity of H5 HPAIV in domestic ducks, an experimental co-infection study was performed. One-week-old domestic ducks were inoculated intranasally and orally with phosphate-buffered saline (PBS) (control) or 10⁶ EID₅₀ of LPAIVs (A/duck/Vietnam/LBM678/2014 (H6N6) or A/Muscovy duck/Vietnam/LBM694/2014 (H9N2)). Seven days later, these ducks were inoculated with HPAIV (A/Muscovy duck/Vietnam/LBM808/2015 (H5N6)) in the same manner. The respective survival rates were 100% and 50% in ducks pre-infected with LBM694 or LBM678 strains and both higher than the survival of the control group (25%). The virus titers in oral/cloacal swabs of each LPAIV pre-inoculation group were significantly lower at 3–5 days post-HPAIV inoculation. Notably, almost no virus was detected in swabs from surviving individuals of the LBM678 pre-inoculation group. Antigenic cross-reactivity among the viruses was not observed in the neutralization test. These results suggest that pre-infection with LPAIV attenuates the pathogenicity of HPAIV in domestic ducks, which might be explained by innate and/or cell-mediated immunity induced by the initial infection with LPAIV.     

Reduced Germination and Seedling Vigor of Weeds with Root Extracts of Maize and Soybean,and the Mechanism Defined as Allelopathic

Journal of Crop Science and Biotechnology - Due to the negative consequences of synthetic herbicides use and their reducing effectiveness due to development of resistant weeds, promotion of...     

Effects of the plant alkaloid thaliblastine on non-cross-resistant and sensitive human leukemia cells in relation with reversal of acquired anthracycline resistance

Thaliblastine exhibits dose dependent cytotoxic effect on HL-60, HL-60/DOX, RHE and HD-MY-2 leukemia cells. Additionally, typical for apoptosis oligonucleosomal DNA fragmentation could be detected in leukemia cells treated with thaliblastine. Moreover, an MDR-phenotype reversing effect of thaliblastine was also identified.     

Resistance mechanism to carboxylic acid amide fungicides in the cucurbit downy mildew pathogen Pseudoperonospora cubensis

BACKGROUND: Pseudoperonospora cubensis, the causal oomycete agent of cucurbit downy mildew, is responsible for enormous crop losses in many species of Cucurbitaceae, particularly in cucumber and melon. Disease control is mainly achieved by combinations of host resistance and fungicide applications. However, since 2004, resistance to downy mildew in cucumber has been overcome by the pathogen, thus driving farmers to rely only on fungicide spray applications, including carboxylic acid amide (CAA) fungicides. Recently, CAA‐resistant isolates of P. cubensis were recovered, but the underlying mechanism of resistance was not revealed. The purpose of the present study was to identify the molecular mechanism controlling resistance to CAAs in P. cubensis. RESULTS: The four CesA (cellulose synthase) genes responsible for cellulose biosynthesis in P. cubensis were characterised. Resistant strains showed a mutation in the CesA3 gene, at position 1105, leading to an amino acid exchange from glycine to valine or tryptophan. Cross‐resistance tests with different CAAs indicated that these mutations lead to resistance against all tested CAAs. CONCLUSION: Point mutations in the CesA3 gene of P. cubensis lead to CAA resistance. Accurate monitoring of these mutations among P. cubensis populations may improve/facilitate adequate recommendation/deployment of fungicides in the field. Copyright © 2011 Society of Chemical Industry     

Comparison of assays for the detection of West Nile virus antibodies in chicken serum

Six tests for the detection of West Nile virus (WNV) antibodies in the serum of experimentally infected chickens were compared. The tests included the hemagglutination-inhibition test (HIT), immunoglobulin M (IgM)-capture enzyme-linked immunosorbent assay (ELISA) with WNV-infected mouse brain antigen, immunoglobulin G (IgG) indirect ELISA with tickborne encephalitis viral antigen, the microtitre virus neutralization test, the standard plaque reduction neutralization test (PRNT), and the microtitre PRNT (micro-PRNT). Thirty adult chickens, intravenously and intramuscularly inoculated with 10⁷ plaque-forming units (PFU) of WNV strain Egypt 101, were bled and given a booster of 10⁷ PFU at 7, 15, and 21 d postinoculation; the final blood collection was on day 28. Although the micro-PRNT is capable of detecting the highest antibody titres during both early and late infection, because of the technical complexity and time requirements of this test a combination of IgM and IgG ELISAs is recommended for serologic screening. Serum samples that give positive results in the ELISAs can then be tested by the micro-PRNT to determine the specificity of antibodies to WNV.     

Evaluation of assays for perinuclear antineutrophilic cytoplasmic antibodies and antibodies to Saccharomyces cerevisiae in dogs with inflammatory bowel disease

OBJECTIVE: To evaluate the use of immunofluorescence asssays for perinuclear antineutrophilic cytoplasmic antibodies (pANCAs) and antibodies to Saccharomyces cerevisiae (ASCAs) in dogs with inflammatory bowel disease (IBD) and assess the clinical value of these serologic markers of the disease. ANIMALS: 39 dogs with IBD, 18 dogs with acute diarrhea, 19 dogs with chronic non-IBD-associated diarrhea, 26 healthy dogs of various breeds and age, and 22 healthy young working dogs. PROCEDURE: Sera obtained from the dogs in each group were added to canine granulocyte- and Saccharomyces cerevisiae-mounted slides for detection of pANCAs and ASCAs via immunofluorescence techniques. Sensitivity and specificity (with 95% confidence intervals [CIs]) were calculated for the group of dogs with IBD versus each of the 2 groups of healthy dogs, the group of dogs with acute diarrhea, and the group of dogs with chronic non-IBD-associated diarrhea. RESULTS: Among the 39 dogs with IBD, 20 yielded positive results via the pANCA assay (sensitivity, 0.51 [95% CI, 0.35 to 0.67]) and 17 yielded positive results via the ASCA assay (sensitivity, 0.44 [95% CI, 0.22 to 0.69]). The specificity of the pANCA assay in the 4 groups of non-IBD-affected dogs ranged from 0.83 (95% CI, 0.85 to 0.96) to 0.95 (95% CI, 0.72 to 1.00). CONCLUSIONS AND CLINICAL RELEVANCE: Immunofluorescence assays for pANCA and ASCA appear to be useful for the detection of IBD in dogs. The pANCA immunofluorescence assay had high specificity for canine IBD, and pANCAs appear to be accurate markers of intestinal inflammation.