Enhancement of immune response and resistance against Vibrio parahaemolyticus in kuruma shrimp (Marsupenaeus japonicus) by dietary supplementation of ß-1,4-mannobiose.

Supplementation of prebiotic carbohydrates can act as a potent immunomodulator and have the efficacy to induce immune-related genes which are involved in host defense. Pure ß-1,4-mannobiose (MNB) showed activation of prophenoloxidase system of shrimp hemocytes in vitro. The resistance of kuruma shrimp Marsupenaeus japonicus against Vibrio parahaemolyticus was examined after the shrimp were fed with 0 (control), 0.02, 0.2, and 2% MNB supplemented diets. The results showed significantly higher survival rates in MNB supplemented shrimp than those of the control one from 2 to 12 days post challenge. In another experiment, the hemocyte count, ROS production, phagocytic, phenoloxidase and bactericidal activities, and expression of immune-related genes were investigated in the control and MNB supplemented groups at day 1, 4, 6, 8 and 11 of the feeding. These immune parameters were significantly enhanced in MNB supplemented groups. Furthermore, the gene expression analysis showed that transcripts of lysozyme, crustin, penaeidin and TNF were significantly up-regulated in hemolymph, lymphoid organs and intestines of MNB treated shrimp. Overall, the results provided evidence that MNB supplementation could improve the immune response and increase shrimp resistance against V. parahaemolyticus infection.

Molecular characterization reveals that squash chlorosis mottling virus and zucchini tigré mosaic virus are the same newly emerging potyvirus.

In 2013, we published the first report of a novel potyvirus isolate, which was tentatively named squash chlorosis mottling virus (SqCMV), from an infected squash plant (Cucurbita pepo) collected in the Homestead area of Florida. The purpose of the current work was to further characterize the virus isolate based on molecular properties, and to determine its relationship to other potyviruses. The complete genome sequence of the virus was 10,292 nucleotides (nt), consisting of a 5'-UTR (182 nt), a complete ORF (10,098 nt) encoding a polyprotein of 3,365 amino acids, a motif for the PIPO protein and a 3'-UTR (112 nt), but excluding the poly-(A) tail. Phylogenetic analysis based on the complete genome and amino acid sequences revealed that the virus from Florida clustered with the type isolate of the newly described potyvirus zucchini tigré mosaic virus (ZTMV) sharing 82-90% nucleotide and 83-86% amino acid identities, respectively. Recombination analysis confirmed one major recombination event in the putative P1 coding region of the virus with the putative parental sequences predicted to resemble to ZTMV-Venezuela and France isolates. In addition, genetic diversity analysis indicated that the CP gene was under the highest selection pressure compared to other genes. Together, these results suggest that SqCMV and ZTMV are both representative isolates of the same species, Zucchini tiger mosaic virus. We present the first complete genome sequence of the ZTMV-HFL isolate from the USA.

Genetic diversity in the 3'-terminal region of papaya ringspot virus (PRSV-W) isolates from watermelon in Oklahoma.

The 3'-terminal region (1191 nt) containing part of the NIb gene, complete coat protein (CP) and poly-A tail of 64 papaya ringspot virus (PRSV-W) isolates collected during 2008-2009 from watermelon in commercial fields of four different counties of Oklahoma were cloned and sequenced. Nucleotide and amino acid sequence identities ranged from 95.2-100% and 97.1-100%, respectively, among the Oklahoman PRSV-W isolates. Phylogenetic analysis showed that PRSW-W isolates clustered according to the locations where they were collected within Oklahoma, and each cluster contained two subgroups. All subgroups of Oklahoman PRSV-W isolates were on separate branches when compared to 35 known isolates originating from other parts of the world, including the one reported previously from the USA. This study helps in our understanding about the genetic diversity of PRSV-W isolates infecting cucurbits in Oklahoma.

Genetic Variability and Evidence of a New Subgroup in Watermelon Mosaic Virus Isolates.

Watermelon mosaic virus (WMV) is one of the important Potyviruses that infect cucurbits worldwide. To better understand the population structure of WMV in the United States (U.S.), 57 isolates were collected from cucurbit fields located in nine southern states. The complete coat protein gene of all WMV isolates was cloned, sequenced and compared with 89 reported WMV isolates. The nucleotide and amino acid sequence identities among the U.S. WMV isolates ranged from 88.9 to 99.7% and from 91.5 to 100%, respectively. Phylogenetic analysis revealed that all the U.S. WMV isolates irrespective of their geographic origin or hosts belonged to Group 3. However, the fifty-seven isolates made three clusters in G3, where two clusters were similar to previously reported subgroups EM1 and EM2, and the third cluster, containing nine WMV isolates, formed a distinct subgroup named EM5 in this study. The ratio of non-synonymous to synonymous nucleotide substitution was low indicating the occurrence of negative purifying selection in the CP gene of WMV. Phylogenetic analysis of selected 37 complete genome sequences of WMV isolates also supported the above major grouping. Recombination analysis in the CP genes confirmed various recombinant events, indicating that purifying selection and recombination are the two dominant forces for the evolution of WMV isolates in the U.S.

Protective effects of garlic extract against hematological alterations, immunosuppression, hepatic oxidative stress, and renal damage induced by cyclophosphamide in rats.

Cyclophosphamide is an alkylating agent widely used as anticancer drug, reported to exert cytotoxic effects attributed to oxidative stress. Therefore, this study aimed to explore the protective effect of ethanolic extract of garlic (EEG) against cyclophosphamide (Cyp)-induced hematological disturbance and immunosuppressive and hepatotoxic effects. Forty male Wistar albino rats were randomized into four equal groups: the normal control one, the Cyp-treated group (50 mg/kg BW/IM, once weekly), the EEG-treated group (300 mg/kg BW, orally, daily), and the Cyp & EEG group. All rats received their relevant treatments for four consecutive weeks. This study revealed that Cyp significantly decreased erythrocyte count, hemoglobin (Hb), packed cell volume (PCV), and total leukocyte and lymphocyte counts. However, the counts of neutrophils, eosinophils, and toxic neutrophils were elevated. Additionally, hepatic malondialdehyde (MDA) and levels of liver and renal biomarkers were significantly elevated in the Cyp-treated group. Otherwise, hepatic catalase (CAT), reduced glutathione (GSH), superoxide dismutase (SOD), and serum total antioxidant capacity (TAC) were significantly lower than the control rats. Furthermore, Cyp significantly reduced whole blood respiratory burst activity (NBT), serum lysozyme and bactericidal activities, interlukin-12 (IL-12), and interferon-γ. In contrast, the levels of nitric oxide (NO), tumor necrosis factor-α (TNF-α), and interlukin-1ß (IL-1ß) were elevated. Additionally, Cyp induced hepatic and renal histopathological alterations. Data in the present study demonstrated that EEG has immunomodulatory and antioxidant effects and has the ability to diminish the alterations induced by Cyp.