RESUMO
Background: the H9N2 subtype of influenza A viruses is considered to be widespread in poultry industry. Adamantane is a group of antiviral agents which is effective both in prevention and treatment of influenza A virus infections. These drugs inhibit M2 protein ion channel which has role on viral replication
Objectives: the main objective of this study is to evaluate M gene of avian influenza viruses [AIVs] of H9N2 subtype in order to find adamantane drug resistance mutations
Methods: over 100 suspected samples were collected from different geographical regions of Iran during 2012-2013. Samples were injected via allantoic sac of 9-11 day-old chicken embryos. A total of 11 out of 100 were AIV. The H9N2 subtype was confirmed by specific RT-PCR. The RT-PCR was conducted for full length M gene. PCR amplified products were purified and then conducted for commercial direct sequencing. Finally, sequences were checked for possible sites of adamantane resistance mutations
Results: overall, 8 out of 11 viruses harbored the adamantine resistance-associated mutations. Of which, four viruses were isolated in 2013 and four viruses in 2012. Two different resistance- associated mutations were observed during different years
Conclusions: the present study provided clear evidence concerning resistance AIVs of H9N2 subtype that were circulating in Iranian poultry sector. This concern is always present as M segment might be introduced into human influenza viruses by reassortment phenomenon
RESUMO
In this study, the immunostimulatory effect of dietary Aloe vera crude extract was investigated in Cyprinus carpio. Three hundred fish were randomly divided into four groups. The first group was immunized with Aeromonas hydrophila bacterin [A.h] and was fed a diet contained 0.5% Aloe vera. The second group was immunized with A.h and fed a diet without Aloe vera. The third group was not immunized and fed with a diet that contained 0.5% Aloe vera. The fourth group remained as the control group and was neither immunized nor fed with Aloe vera supplements. Blood samples were taken every 14 d for eight weeks and samples were analyzed for hematological and immunological parameters. White blood count [WBC], red blood count [RBC], packed cell volume [PCV], lysozyme activity, serum bactericidal activity, complement activity, total protein, IgM concentration and specific A. hydrophila antibody were assessed. At the end of treatment, 20 fish from each group were challenged with A. hydrophila. WBC value, antibody level, lysozyme and bactericidal activity were significantly increased in the serum of fish treated with Aloe vera [p<0.05]. No significant differences were seen in the RBC, PCV or complement activity among the groups. The relative percent survival [RPS] was found to be increased in fish fed with Aloe vera. This study indicates that the oral administration of Aloe vera is able to enhance some specific and non-specific immune responses in the common carp