Genetic and antigenic variance of foot-and-mouth disease virus type Asia1

The capsid protein encoding genes of five recent type Asia1 foot-and-mouth disease virus isolates, representative of three genotypes, were sequenced. The deduced amino acid sequences were aligned to each other and to two published sequences. The sequence differences suggested different antigenic properties of the isolates. One isolate was used to generate monoclonal antibodies (mAbs) which were analyzed for neutralizing activity and reactivity with trypsinized virus. Trypsin removes the major antigenic sites located at VP1. The five virus isolates formed three reaction patterns with the mAbs, irrespective of their genotype. Combination of all data allowed to suggest the location of the epitope of each antibody: the VP1 G-H and the VP2 B-C loop, the VP3 B-B knob, and the N-terminus of VP2, respectively, were involved.

Beneficial effects of probiotic and phytobiotic as growth promoter alternative to antibiotic for safe broiler production

Objectives:

Drug residues in poultry products could lead to the development of antibiotic-resistant bacteria as in any living animal and human alike. Extensive use of antibiotics in animals to promote growth rate, increase feed efficiency, and for prevention of intestinal infections has led to the development of resistant bacteria in the gastrointestinal tract. The present study was conducted to evaluate the effects of biological supplementation of probiotic, phytobiotic, and their combination over antibiotic on growth performance, microbial load, and hematological parameters in Broiler.

Materials and methods:

Sixty-five broiler chicken were divided into five groups (12 birds in each group), namely, group A (basal diet), group B (antibiotic, Renamycin 100®), group C (phytobiotic, Galibiotic®), group D (probiotic, Bio-Top®), and group E (combination, Galibiotic®+Galibiotic®) and five were sacrificed for baseline data on day 0.

Results:

Average final live weight gain was highest in group D (probiotic) than other groups. The feed conversion ratio was highest in group A and lowest in the probiotic group (group C). Blood samples were collected on 14th and 28th day for hematological studies. The mean hematology values regarding the total erythrocyte count, hemoglobin concentration, packed cell volume, and erythrocyte sedimentation rate differed significantly (p < 0.05) among groups. The pH of all the treatment groups was significantly decreased compared to the control group (p < 0.05) where group C was significantly (p < 0.05) lower than all other groups. Highest total viable cell count was observed in control (group A) and total coliform count in phytobiotic (group C) was significantly lower than in other treatment groups (p < 0.05).

Conclusion:

It may conclude that biological supplements have a significant positive impact on growth performance, hematological parameters, and gut microbial load in broiler chicken of which the probiotic showing the best effects. Supplementation of probiotic in feed could be one of the best candidates as an alternative to antibiotics as growth promoter for safe broiler production.

Epidemiological implications of the molecular characterization of foot-and-mouth disease virus isolated between 1996 and 2000 in Bangladesh

Foot-and-mouth disease virus was collected during two years throughout Bangladesh. Viral RNA from 40 samples was subjected to reverse transcription-dependent polymerase chain reactions that amplify parts of the capsid protein encoding genome region, and the products obtained were sequenced. This showed that all virus isolates up to January 1999 belonged to a genotype of serotype O, observed here already in 1987, 1996 and 1997, and elsewhere since 1990. In February 2001, this virus variant was introduced into Great Britain and then transmitted to other European countries. The capsid protein sequences of an isolate of 2001 from the Netherlands is provided. Later isolates from Bangladesh, however, belonged to a genotype of serotype A that had been transmitted to Albania in 1996. No virus of type Asia1 was found, although it circulated in Bangladesh in 1996. Instead, this genotype of Asia1 virus was observed in Iran late in 1999, and transmitted from Turkey to Greece in July 2000. The results indicate continued intercontinental transmission of foot-and-mouth disease viruses that circulate in central Asia.

Dose-dependent response to phytobiotic supplementation in feed on growth, hematology, intestinal pH, and gut bacterial load in broiler chicken

Objective:

The present study was aimed to evaluate dose-dependent effects of phytobiotic (Galibiotic) supplements in feed on growth performance, hematological parameters, intestinal pH, and gut bacterial population in broiler chick.

Materials and Methods:

A total of 50 ten day old broiler chicks were divided into five groups, namely, Group A as control (without galibiotic), Group B (galibiotic at 1 gm/kg feed), Group C (galibiotic at 2 gm/kg feed), Group D (galibiotic at 5 gm/kg feed), and Group E (galibiotic at 10 gm/kg feed). All the birds were reared for 42 days and samples were collected before and after sacrifice.

Results:

Live body weights showed no significant differences between the groups but overall feed conversion ratios (FCRs) of treatment groups were significantly low in Group E having the lowest. Blood samples collected for hematology differed significantly (p < 0.01) among the different groups. Intestinal pH was lower in treatment groups with Group E having the lowest. Cecal total viable count was highest in Group A and lowest in Group E. The cecal coliform count was low in all the treatment groups.

Conclusion:

Along with previously published report, it may conclude that the phytobiotic could be used as an alternative to antibiotics due to positive growth performance, lower FCR, carcass quality, and improved gut health of broiler chicks.

Population Genomics of an Anadromous Hilsa Shad Tenualosa ilisha Species across Its Diverse Migratory Habitats: Discrimination by Fine-Scale Local Adaptation

The migration of anadromous fish in heterogenic environments unceasingly imposes a selective pressure that results in genetic variation for local adaptation. However, discrimination of anadromous fish populations by fine-scale local adaptation is challenging because of their high rate of gene flow, highly connected divergent population, and large population size. Recent advances in next-generation sequencing (NGS) have expanded the prospects of defining the weakly structured population of anadromous fish. Therefore, we used NGS-based restriction site-associated DNA (NextRAD) techniques on 300 individuals of an anadromous Hilsa shad (Tenualosa ilisha) species, collected from nine strategic habitats, across their diverse migratory habitats, which include sea, estuary, and different freshwater rivers. The NextRAD technique successfully identified 15,453 single nucleotide polymorphism (SNP) loci. Outlier tests using the F_ST OutFLANK and pcadapt approaches identified 74 and 449 SNPs (49 SNPs being common), respectively, as putative adaptive loci under a divergent selection process. Our results, based on the different cluster analyses of these putatively adaptive loci, suggested that local adaptation has divided the Hilsa shad population into two genetically structured clusters, in which marine and estuarine collection sites were dominated by individuals of one genetic cluster and different riverine collection sites were dominated by individuals of another genetic cluster. The phylogenetic analysis revealed that all the riverine populations of Hilsa shad were further subdivided into the north-western riverine (turbid freshwater) and the north-eastern riverine (clear freshwater) ecotypes. Among all of the putatively adaptive loci, only 36 loci were observed to be in the coding region, and the encoded genes might be associated with important biological functions related to the local adaptation of Hilsa shad. In summary, our study provides both neutral and adaptive contexts for the observed genetic divergence of Hilsa shad and, consequently, resolves the previous inconclusive findings on their population genetic structure across their diverse migratory habitats. Moreover, the study has clearly demonstrated that NextRAD sequencing is an innovative approach to explore how dispersal and local adaptation can shape genetic divergence of non-model anadromous fish that intersect diverse migratory habitats during their life-history stages.

Depression, anxiety, and stress among public university students in Bangladesh during the COVID-19 pandemic

“Coronaphobia” has spread across the world due to the overwhelming impact of coronavirus-2019 (COVID-19). The education sector has suffered from the pandemic, and university students find themselves in an unprecedented situation. Many university students in Bangladesh require psychological intervention due to adverse mental health conditions created by the COVID-19 pandemic. This cross-sectional study was conducted to evaluate the psycho­logical conditions among public university students in Bangladesh during university campus closures necessitated by the pandemic. It also sought to ascertain factors associated with adverse psychological conditions during this period. Convenience and snowball sampling techniques were employed. In all, 1,382 university students participated in an online survey during the COVID-19 pandemic. Relationships between student demographic factors and DASS 21 subscales were determined using linear regression models. Students were classified as suffering from anxiety (26.85 percent), normal depression (25.47 percent), moderate depression (29.52 percent), or extremely severe depression (17.73 percent). Students who lived with their families reported less adverse mental health. Factors strongly associated with students’ psychological conditions include age, academic field, university year, perception of their own mental health condition during the COVID-19 pandemic, safety concerns about their living place relative to COVID-19, perceptions about social life, academic profile, academic performance, concerns about pandemic impact on their studies, and part-time jobs during the pandemic. Outcomes of this research may assist social organizations and health workers to identify psychologically vulnerable university students in order to support them more effectively. Our findings could also be integrated into comprehensive pandemic control efforts.

Reproductive Biology and Ecology of the Green Mussel Perna viridis: A Multidisciplinary Approach

A multidisciplinary approach was applied to explore deeper knowledge about the reproductive biology and ecology of the green mussel (Perna viridis) by interlinking among ecological factors, ingested gut plankton, gonad fatty acid profile, and reproductive traits. Mussels were collected throughout the year from the coastal region of the Bay of Bengal of Bangladesh, and the histological analysis of 242 mussels revealed five stages of gametogenesis with an annual spawning season from January to April. The gonadosomatic index showed a strong correlation with the water quality parameters, ingested gut plankton groups, and gonadal fatty acids, and also displayed prominent effects of seasonality. In all datasets, we performed principal component analysis in which the first two principal components showed that seasonality explained >65% of the variability, and the multivariate spaces of seasonality corresponded to the gonad development. High salinity, nutrients, chlorophyll a, and plankton abundance in the water column were positively correlated with gonad development and the spawning of mussels. During the development stage, mussel ingested more plankton, particularly Bacillariophyceae and Pyrrophyceae, which were an important source of increased n-3 polyunsaturated fatty acids content in gonads. Furthermore, gonads accumulated more lipids and saturated fatty acids during the mature and spawning stages, which were probably utilized during embryogenesis and early larval development as energy sources and constituents of the cell membrane. This research provides a model toward a better understanding of reproductive biological traits and how these traits are interrelated with the surrounding environmental variables of the green mussel, which would be helpful in marine aquaculture and the sustainable exploitation of the fishery resources.

Strip Tillage and Crop Residue Retention Decrease the Size but Increase the Diversity of the Weed Seed Bank under Intensive Rice-Based Crop Rotations in Bangladesh

Cropping under conservation agriculture (CA) has become increasingly attractive among farmers in recent years. However, weed control may be more difficult during the transition to CA from conventional establishment methods due to the reduction in tillage intensity. Conversely, CA changes to weed dynamics can alter the weed seed bank in the longer run. In Bangladesh’s intensively cropped rice-based rotations, the nature of weed seed bank shifts over time after adopting CA are poorly known. Two 2-year studies were sampled from on-farm CA experiments under wheat-mungbean-winter rice and monsoon rice-mustard-winter rice rotations. We investigated the effects of reduced soil disruption in the form of strip-tillage (ST) combined with increased deposition of standing reside from previous crops (0 vs. 50%). The weed seed bank in 0–5, 5–10, and 10–15 cm depths of soil were quantified in a shade-house experiment by measuring weed emergence over 12 months in seedling trays. After 2 years of field study, the year-round count of emerged weeds from the seed bank showed that ST plus 50% mulch had a lower weed abundance and biomass and fewer weed species than that of conventional tillage (CT) without residue. The perennial weeds Ageratum conyzoides L., Alternanthera philoxeroides L., Cynodon dactylon L., Cyperus rotundus L., Jussia decurrence Walt., Leersia hexandra L., Scirpus mucronatus (L.) Palla., and Solanum torvum Sw. were enriched in the smaller-sized ST seed banks in terms of both density and biomass. The CT, on the other hand, was dominated by annual weeds: Cyperus difformis L., Cyanotis axillaris Roem., Echinochloa crus-galli (L.) Beauv., Eleusine indica L., Fimbristylis miliacea (L.) Vahl., and Rotala ramosior L. Overall, ST plus 50% residue had a more diverse seed bank than CT without mulch. The majority of weed seeds were amassed in the 0–5 cm soil depth of the ST, while most of them were accumulated in the 10–15 cm layer of the CT. The wheat-mungbean-winter rice rotation had a more diverse floristic composition with many more weed species than the monsoon rice-mustard-winter rice rotation.