Fish Gut Microbiome: Current Approaches and Future Perspectives

In recent years, investigations of microbial flora associated with fish gut have deepened our knowledge of the complex interactions occurring between microbes and host fish. The gut microbiome not only reinforces the digestive and immune systems in fish but is itself shaped by several host-associated factors. Unfortunately, in the past, majority of studies have focused upon the structure of fish gut microbiome providing little knowledge of effects of these factors distinctively and the immense functional potential of the gut microbiome. In this review, we have highlighted the recently gained insights into the diversity and functions of the fish gut microbiome. We have also delved on the current approaches that are being employed to study the fish gut microbiome with an aim to collate all the knowledge gained and make accurate conclusions for their application based perspectives. The literature reviewed indicated that the future research should shift towards functional microbiomics to improve the maximum sustainable yield in aquaculture.     

Susceptibility of Murine Norovirus and Hepatitis A Virus to Electron Beam Irradiation in Oysters and Quantifying the Reduction in Potential Infection Risks

Consumption of raw oysters is an exposure route for human norovirus (NoV) and hepatitis A virus (HAV). Therefore, efficient postharvest oyster treatment technology is needed to reduce public health risks. This study evaluated the inactivation of HAV and the NoV research surrogate, murine norovirus-1 (MNV-1), in oysters (Crassostrea virginica) by electron beam (E-beam) irradiation. The reduction of potential infection risks was quantified for E-beam irradiation technology employed on raw oysters at various virus contamination levels. The E-beam dose required to reduce the MNV and HAV titer by 90% (D₁₀ value) in whole oysters was 4.05 (standard deviations [SD], ±0.63) and 4.83 (SD, ±0.08) kGy, respectively. Microbial risk assessment suggests that if a typical serving of 12 raw oysters was contaminated with 10⁵ PFU, a 5-kGy treatment would achieve a 12% reduction (from 4.49 out of 10 persons to 3.95 out of 10 persons) in NoV infection and a 16% reduction (from 9.21 out of 10 persons to 7.76 out of 10 persons) in HAV infections. If the serving size contained only 10² PFU of viruses, a 5-kGy treatment would achieve a 26% reduction (2.74 out of 10 persons to 2.03 out of 10 persons) of NoV and 91% reduction (2.1 out of 10 persons to 1.93 out of 100 persons) of HAV infection risks. This study shows that although E-beam processing cannot completely eliminate the risk of viral illness, infection risks can be reduced.     

First Report of Botryosphaeria dothidea on Mangifera indica L. in Gujarat

A leaf spot disease was observed on Mangifera indica L. located in the region of Rajkot, Gujarat, India. The symptoms included the appearance of small, circular to oval dark brown necrotic sunken spots on the leaves. The fungus formed grey to dark grey on potato dextrose agar and conidia were single‐celled, ovoid or oblong. On the basis of mycological characteristics, pathogenicity test and molecular identification using 28S rDNA sequence and internal transcribed spacer (ITS), the fungus was identified as Botryosphaeria dothidea. To the best of our knowledge, this is the first report of leaf spot on M. indica tree caused by Botryoshaeria dothidea in Gujarat, India.     

Cutting edge: L-selectin (CD62L) expression distinguishes small resting memory CD4+ T cells that preferentially respond to recall antigen

Naive CD4+ T cells use L-selectin (CD62L) expression to facilitate immune surveillance. However, the reasons for its expression on a subset of memory CD4+ T cells are unknown. We show that memory CD4+ T cells expressing CD62L were smaller, proliferated well in response to tetanus toxoid, had longer telomeres, and expressed genes and proteins consistent with immune surveillance function. Conversely, memory CD4+ T cells lacking CD62L expression were larger, proliferated poorly in response to tetanus toxoid, had shorter telomeres, and expressed genes and proteins consistent with effector function. These findings suggest that CD62L expression facilitates immune surveillance by programming CD4+ T cell blood and lymph node recirculation, irrespective of naive or memory CD4+ T cell phenotype.     

Advances in schizophrenia

Recent studies into the etiology of schizophrenia have yielded both promising leads and disappointing dead ends, indicating the multifactored and complex nature of the disorder. The focus has subsequently shifted back to refining the phenotype and identifying clinical and biological subtypes. Recent technological breakthroughs in genomics and proteomics hold promise for advancing our understanding of the molecular pathophysiology of schizophrenia.     

Role of peroxidases and glycosidases in regulation of sink size in developing seeds of Hibiscus esculentum

Changes in peroxidases and glycosidases activities in cytoplasmic and ionically wall-bound fraction of developing seed of Hibiscus esculentum were studied. In both fractions, the activity of peroxiases assayed with ferulic acid and caffeic acid as a hydrogen donors, showed inverse correlation with the cell enlargement (sink size development phase). Activities of glycosidases, on the other hand, showed positive correlation with the sink development and sink filling period of the developing seed. The role of both the enzymes, glycosidases and peoxidase in seed development is discussed.     

Evaluation of the anti-<Emphasis Type="Italic">Fusarium oxysporum</Emphasis> f. sp <Emphasis Type="Italic">cicer</Emphasis> and anti-<Emphasis Type="Italic">Alternaria porri</Emphasis> effects of some essential oils

The anti-Fusarium oxysporum f. sp cicer (FOC) and anti-Alternaria porri (A. porri) effects were evaluated for 75 different essential oils. The most active essential oils found were those of lemongrass, clove, cinnamon bark, cinnamon leaf, cassia, fennel, basil and evening primrose. However, the effectiveness of these essential oils with both the tested fungi showed different responses. The level of inhibition was compared with Hexaconazole. GC–MS analysis for five oils amongst the 75 essential oils tested was performed. The potential of these essential oils as an ecofriendly and economic approach as a fungicide for FOC and A. porri is discussed.