Comparative pathogenicity of a genotype XXI.1.2 pigeon Newcastle disease virus isolate in pigeons and chickens.

Here, we performed molecular and pathogenic characterization of a Newcastle disease virus (NDV) isolate from pigeons in Bangladesh. Molecular phylogenetic analysis based on the complete fusion gene sequences classified the three study isolates into genotype XXI (sub-genotype XXI.1.2) together with recent NDV isolates obtained from pigeons in Pakistan (2014-2018). The Bayesian Markov Chain Monte Carlo analysis revealed that the ancestor of Bangladeshi pigeon NDVs and the viruses from sub-genotype XXI.1.2 existed in the late 1990s. Pathogenicity testing using mean embryo death time pathotyped the viruses as mesogenic, while all isolates carried multiple basic amino acid residues at the fusion protein cleavage site. Experimental infection of chickens and pigeons revealed no or minimum clinical signs in chickens, while a relatively high morbidity (70%) and mortality (60%) were observed in pigeons. The infected pigeons showed extensive and systemic lesions including hemorrhagic and/or vascular changes in the conjunctiva, respiratory and digestive system and brain, and atrophy in the spleen, while only mild congestion in the lungs was noticed in the inoculated chickens. Histologically, consolidation in the lungs with collapsed alveoli and edema around the blood vessels, hemorrhages in the trachea, severe hemorrhages and congestion, focal aggregation of mononuclear cells, and single hepatocellular necrosis in the liver, severe congestion, multifocal tubular degeneration, and necrosis, as well as mononuclear cell infiltration in the renal parenchyma, encephalomalacia with severe neuronal necrosis with neuronophagia were noticed in the brain in infected pigeons. In contrast, only slight congestion was found in lungs of the infected chickens. qRT-PCR revealed the replication of the virus in both pigeons and chickens; however, higher viral RNA loads were observed in oropharyngeal and cloacal swabs, respiratory tissues, and spleen of infected pigeons than the chickens. In conclusion, genotype XXI.1.2 NDVs are circulating in the pigeon population of Bangladesh since 1990s, produce high mortality in pigeons with pneumonia, hepatocellular necrosis, renal tubular degeneration, and neuronal necrosis in pigeons, and may infect chickens without overt signs of clinical disease and are likely to shed viruses via the oral or cloacal routes.

Comparative pathogenicity of infectious bursal disease viruses of three different genotypes.

Infectious bursal disease (IBD) is a highly immunosuppressive and often fatal viral disease of young chickens. The causal agent IBD virus (IBDV) is an avian Birnavirus having two genome segments that have evolved independently and contributed to the emergence of many genotypes with different pathogenic profile. The present study aimed at genetic and pathogenic characterization of IBDVs from Bangladesh. We performed phylogenetic analysis of 15 IBDV isolates recovered from field outbreaks in chickens during 2020-2021 and compared the pathogenicity of three selected isolates belonging to different genotypes on experimental infection in chickens. Out of 15 isolates, one was the typical vvIBDV of genotype A3B2, 13 were reassortant vvIBDV of genotype A3B3 having very virulent-like segment A and early Australian-like segment B, and the remaining one isolate was a classical virulent IBDV of A1aB1 genotype. A few amino acid substitutions were observed between the genotypes in four putative antigenic sites on VP2. In a comparative pathogenicity study, the typical vvIBDV isolate BD-25(A3B2) appeared to be the most virulent with 100% morbidity and 90% mortality, followed by the segment-reassortant vvIBDV isolate BD-28(A3B3) with 50% morbidity and 30% mortality. However, the gross and histopathological lesions in the bursa of Fabricius were similar. The classical virulent isolate BD-26(A1aB1) did not cause any clinical disease. In conclusion, three genotypes of IBDV are co-circulating in poultry of Bangladesh and the typical vvIBDV of A3B2 genotype was more virulent than the reassortant vvIBDV of A3B3 genotype. Further studies are required to assess the country-wide distribution of IBDV of different genotypes and the efficacy of the currently available vaccines in protecting chickens against different genotypes of IBDV in Bangladesh.

Genetic and biological characterization of Newcastle disease viruses circulating in Bangladesh during 2010-2017: further genetic diversification of class II genotype XIII in Southcentral Asia.

Newcastle disease virus (NDV) is endemic in Bangladesh and is a major threat to commercial poultry operations. While complete fusion (F) genes are recommended for molecular characterization and classification of NDV isolates, heretofore, only partial F gene data have been available for Bangladeshi NDVs. To this end, we obtained the full-length F gene coding sequences of 11 representative NDVs isolated in Bangladesh between 2010 and 2017. In addition, one of the viruses (MK934289/chicken/Bangladesh/C161/2010) was used in an experimental infection of chickens to establish the viral pathotype and study gross and microscopic lesions. Phylogenetic analysis provided evidence that all studied Bangladeshi isolates belong to genotype XIII.2 of class II NDVs. Six of the viruses were isolated between 2010 and 2017 and grouped together with isolates from neighbouring India during 2013-2016. Another four Bangladeshi isolates (2010-2016) formed a separate monophyletic branch within XIII.2 and showed high nucleotide distance from the isolates from India and the other six Bangladeshi viruses within the sub-genotype; however, none of these groups fulfils all classification criteria to be named as a separate sub-genotype. The eleventh Bangladeshi virus studied here (C162) was genetically more distant from the remaining isolates. It out-grouped the viruses from sub-genotypes XIII.2.1 and XIII.2.2 and showed more than 9.5 % nucleotide distance from all genotype XIII sub-genotypes. This isolate may represent an NDV variant that is evolving independently from the other viruses in the region. The experimental infection in chickens revealed that the tested isolate (C161) is a velogenic viscerotropic virus. Massive haemorrhages, congestion and necrosis in different visceral organs, and lymphoid depletion in lymphoid tissues, typical for infection with velogenic NDV, were observed. Our findings demonstrate the endemic circulation of sub-genotype XIII.2 in Southcentral Asia and further genetic diversification of these viruses in Bangladesh and neighbouring India. This constant evolution of the viruses may lead to the establishment of new genetic groups in the region. Additional historical and prospective virus and surveillance data from the region and neighbouring countries will allow a more detailed epidemiological inference.

Comparison of clinical manifestation of dengue fever in Bangladesh: an observation over a decade.

BACKGROUND: The clinical presentation of dengue fever had been observed to change with time since its first outbreak in 2000 in Bangladesh. This report showed the clinical presentation of the 2019 outbreak in Bangladesh along with its comparison to previous outbreaks witnessed in this region. METHODS: This hospital-based cross-sectional study was conducted in one of the largest tertiary care hospitals in Dhaka city. A total of 553 laboratory-confirmed and 194 probable dengue cases were interviewed. The clinical manifestation of the confirmed cases of the current outbreak was compared with three of the outbreak reports retrieved from the databases. R version 3.6.3 was used for data analysis. RESULTS: Among the confirmed cases, two-thirds were male (63.2%) and the average age was 27(± 11) years. Positive tests for NS1 and IgM were present in 99.6% (n = 525/527) and 82.6% (n = 38/46) of the cases, respectively. Thrombocytopenia was present in 66.1% of cases. Fever (100%) was common for all. Gastrointestinal (GIT) features, including abdominal pain (86.5%), anorexia and/or vomiting (69.6%), and Diarrhea (> 3 motions/day) (26.2%) were more frequent than typical rash and other pain symptoms. Hypotension was present in approximately a quarter of patients (25%). GIT features (anorexia, nausea, and/or vomiting) and hypotension were more common among adult participants while bleeding manifestation (melena and vaginal bleeding, p = 0.009 & 0.032) was more frequent in pediatric patients. Compared to outbreaks of 2008, 2016, and 2018, increasing trends in GIT symptoms e.g. anorexia, abdominal pain, and diarrhea were observed. While a negative trend in hemorrhagic manifestations (skin rash, melena, and conjunctival hemorrhage/hemorrhagic sclera) and arthralgia/joint pain were found. CONCLUSION: The present outbreak was noticeably characterized by GIT symptoms and hypotension in addition to the typical clinical features like rash and pain symptoms. An increasing trend in GIT features and decreasing trend in hemorrhagic manifestations was noted over the last decade of dengue outbreaks.

A unified genotypic classification of infectious bursal disease virus based on both genome segments.

Infectious bursal disease virus (IBDV) of chickens is a birnavirus with a bi-segmented double-stranded RNA genome, the segments designated as A and B. We performed phylogenetic analysis using a 366-bp fragment of segment A (nt 785-1150) and a 508-bp fragment of segment B (nt 328-835) of IBDV. A total of 463 segment A and 434 segment B sequences from GenBank, including the sequences of eight recent Bangladeshi isolates, were used in the analysis. The analysis revealed eight genogroups of segment A under serotype 1, designated as A1 (classical), A2 (US antigenic variant), A3 (very virulent), A4 (dIBDV), A5 (atypical Mexican), A6 (atypical Italian), A7 (early Australian) and A8 (Australian variant), and a single genogroup under serotype 2, designated as A0. On the other hand, segment B could be categorized into five genogroups irrespective of serotype, these being B1 (classical-like), B2 (very virulent-like), B3 (early Australian-like), B4 (Polish & Tanzanian) and B5 (Nigerian). Segment B of serotype 2 strains clustered within genogroup B1. With the bi-segmented genome of IBDV, these differences would allow for a total of 45 possible assortments. Based on the combinations of segment A and segment B genogroups observed in 463 IBDV strains, a total of 15 genotypes could be recognized. Recent Bangladeshi IBDV strains, isolated in 2016, appeared to be segment reassortants having segment A of genogroup A3 (very virulent) and segment B of genogroup B3 (early Australian-like). An extended system of nomenclature of IBDV strains is proposed.

Active virological surveillance in backyard ducks in Bangladesh: detection of avian influenza and gammacoronaviruses.

Domestic waterfowl play an important role in the perpetuation and transmission of avian pathogens including avian influenza viruses (AIV) of low and high pathogenicity, which pose severe economic and public health concerns in Bangladesh. This study focused on active surveillance of several avian viral pathogens with a special reference to AIV in selected backyard duck populations in Bangladesh. A total of 500 pooled oropharyngeal and cloacal samples from individual ducks of four districts were tested by real time PCRs for the presence of AIV, avian avulavirus-1, anatid herpesvirus-1, avian parvovirus, avian bornavirus and avian coronavirus. The investigation identified 27 (5.4%) ducks positive for AIV and 12 (2.4%) positive for avian coronavirus. In 13 samples, RNA specific for AIV H4N6 was detected. Phylogenetic analysis of the AIV haemagglutinin H4 and neuraminidase N6 genes suggested a clustering of Bangladeshi AIV H4N6 in Eurasian lineage group 2. Other AIV positive samples had very low virus loads (Cq > 36) and were not subtyped. Coronaviral sequences of a fragment of the polymerase gene were related to Eurasian-Australian duck gamma-coronaviruses. Our current active surveillance in free-range domestic backyard ducks in Bangladesh failed to detect highly pathogenic (HP) AIV in contrast to our previous passive monitoring study. Nevertheless, active monitoring of domestic duck populations may be important to highlight presence and transmission dynamics of economically less important AIV that still may serve as reassortment partners for the generation of new HP and zoonotic AIV. RESEARCH HIGHLIGHTS Active surveillance for viral pathogens in domestic free-range backyard ducks. Detection of avian influenza virus subtype H4N6. First identification of avian gammacoronavirus in ducks in Bangladesh.

Pathology of clade 2.3.2.1 avian influenza virus (H5N1) infection in quails and ducks in Bangladesh.

We performed pathological and molecular virological investigation of three outbreaks of highly pathogenic avian influenza (HPAI) in a quail farm and two duck farms of Mymensingh and Netrokona districts of Bangladesh in 2011. HPAI viruses of subtype H5N1 were detected from all three outbreaks and phylogenetic analysis of HA gene sequence placed the viruses into clade 2.3.2.1. The outbreak in the quail farm was characterized by acute death with 100% mortality within two days. Marked haemorrhages and congestion with necrotic and inflammatory lesions in the respiratory tract, liver, pancreas and kidneys were the major gross and histopathological lesions. In the case of ducks, nervous signs were the remarkable clinical manifestations and the mortality was around 10%. No significant gross lesions were observed at necropsy. Non-purulent encephalitis with gliosis and neuronal degeneration was observed on histopathological examination. By immunohistochemistry, viral antigen could be detected in different organs of both quails and ducks. This study records varying clinical and pathological manifestations of HPAI in ducks and quails following natural infection with the same strain of the virus. RESEARCH HIGHLIGHTS HPAIV of clade 2.3.2.1 was detected from clinical outbreaks in quails and ducks Sudden death with severe haemorrhages in various organs was found in quails Pronounced nervous signs with non-purulent encephalitis were observed in ducks Viral antigen could be localized in different organs by immunohistochemistry.

Laparoscopic and robotic specimen retrieval system (Modified Nadiad Bag): Validation and cost-effectiveness study model.

AIM: To construct and validate a cost-effective indigenously made retrieval system (Modified Nadiad bag) in minimal access urology. METHOD: The components of the modified Nadiad bag are a polyethylene roll, fishnet thread, and a 5 Fr ureteral catheter. The bag is indigenously made in our institute and used for organ retrieval after proper sterilization. The video recordings of entrapments and retrievals done over the past few months were reviewed. The procedures under review in which the bag was used were: Robot Assisted Radical Prostatectomy (50 cases), laparoscopic radical nephrectomy (50 cases), laparoscopic simple nephrectomy (50 cases) and laparoscopic adrenalectomy (18 cases). We also compared the retrieval time with experts and novices. RESULTS: The retrieval times, the organ size (largest dimension) and specimen weight were records for each case. Multivariate analysis of the data was done and we extrapolated the retrieval time with organ size, specimen weight and expertise of the surgeon. There was no significant difference among expert surgeons and novice surgeons with regards to retrieval times (p value = 0.29), with regards to organ size (p value = 0.83) and with regards to specimen weight (p value = 0.99). CONCLUSION: Our design of retrieval system offers a cost-effective option which is easy to make, without the risk of tumor seeding and without the need for separate access sheath. It's a retrieval system which has proved its efficacy in laparoscopic as well as robotic procedures with no bearing on the expertise of the surgeon involved.

Review analysis and impact of co-circulating H5N1 and H9N2 avian influenza viruses in Bangladesh.

Almost the full range of 16 haemagglutinin (HA) and nine neuraminidase subtypes of avian influenza viruses (AIVs) has been detected either in waterfowl, land-based poultry or in the environment in Bangladesh. AIV infections in Bangladesh affected a wide range of host species of terrestrial poultry. The highly pathogenic avian influenza (AI) H5N1 and low pathogenic AI H9N2 were found to co-circulate and be well entrenched in the poultry population, which has caused serious damage to the poultry industry since 2007. By reviewing the available scientific literature, the overall situation of AIVs in Bangladesh is discussed. All Bangladeshi (BD) H5N1 and H9N2 AIV sequences available at GenBank were downloaded along with other representative sequences to analyse the genetic diversity among the circulating AIVs in Bangladesh and to compare with the global situation. Three different H5N1 clades, 2.2.2, 2.3.2.1 and 2.3.4.2, have been detected in Bangladesh. Only 2.3.2.1a is still present. The BD LP H9N2 viruses mostly belonged to the H9 G1 lineage but segregated into many branches, and some of these shared internal genes with HP viruses of subtypes H7N3 and H5N1. However, these reassortment events might have taken place before introduction to Bangladesh. Currently, H9N2 viruses continue to evolve their HA cleavage, receptor binding and glycosylation sites. Multiple mutations in the HA gene associated with adaptation to mammalian hosts were also observed. Strict biosecurity at farms and gradual phasing out of live-bird markets could be the key measures to better control AIVs, whereas stamping out is not a practicable option in Bangladesh. Vaccination also could be an additional tool, which however, requires careful planning. Continuous monitoring of AIVs through systematic surveillance and genetic characterisation of the viruses remains a hallmark of AI control.

Phylogenetic analysis of Newcastle disease viruses from Bangladesh suggests continuing evolution of genotype XIII.

A total of 23 Newcastle disease virus (NDV) isolates from Bangladesh taken between 2010 and 2012 were characterized on the basis of partial F gene sequences. All the isolates belonged to genotype XIII of class II NDV but segregated into three sub-clusters. One sub-cluster with 17 isolates aligned with sub-genotype XIIIc. The other two sub-clusters were phylogenetically distinct from the previously described sub-genotypes XIIIa, XIIIb and XIIIc and could be candidates of new sub-genotypes; however, that needs to be validated through full-length F gene sequence data. The results of the present study suggest that genotype XIII NDVs are under continuing evolution in Bangladesh.

Serological and virological surveillance of avian influenza virus in domestic ducks of the north-east region of Bangladesh.

BACKGROUND: Wild waterfowl are considered as the natural reservoir for avian influenza (AI) viruses. Bangladesh has been experiencing highly pathogenic avian influenza (HPAI) outbreaks since 2007, mostly in chickens and occasionally in ducks. Ducks play an important role in the persistence and genetic recombination of AI viruses. This paper presents the results of serological and virological monitoring of AI in domestic ducks in 2013 in the north-east region of Bangladesh. RESULTS: A total of 871 and 662 serum samples and 909 and 302 pairs of cloacal and oropharyngeal swabs from domestic ducks of Mymensingh and Sylhet division, respectively, were analysed. Antibodies to type A influenza virus were detected by blocking ELISA in 60.73 and 47.73% serum samples of Mymensingh and Sylhet division, respectively. On haemagglutination-inhibition (HI) test 17.5% of ELISA positive serum samples were found to be seropositive to H5 avian influenza virus. Five cloacal swabs and one oropharyngeal swab were positive for M gene of type A influenza virus by real time RT-PCR (rRT-PCR), but all of them were negative for H5 influenza virus. Three of the six viruses were successfully characterized as H1N5, H2N5 and H7N5 subtype of AI virus, the other three remained uncharacterized. On sequencing and phylogenetic analysis the HA and NA genes were found to be of Eurasian avian lineage. The H7 virus had cleavage site motif of low pathogenic virus. CONCLUSIONS: Low pathogenic avian influenza viruses were detected from apparently healthy domestic ducks. A small proportion of domestic ducks were found seropositive to H5 AI virus.

Normobaric hyperoxia treatment prevents early alteration in dopamine level in mice striatum after fluid percussion injury: a biochemical approach.

Dopamine (DA) is one of the key neurotransmitters in the striatum, which is functionally important for a variety of cognitive and motor behaviours. It is known that the striatum is vulnerable to damage from traumatic brain injury (TBI). However, a therapeutic approach has not yet been established to treat TBI. Hence, the present work aimed to evaluate the ability of Normobaric hyperoxia treatment (NBOT) to recover dopaminergic neurons following a fluid percussion injury (FPI) as a TBI experimental animal model. To examine this, mice were divided into four groups: (i) Control, (ii) Sham, (iii) FPI and (iv) FPI+NBOT. Mice were anesthetized and surgically prepared for FPI in the striatum and immediate exposure to NBOT at various time points (3, 6, 12 and 24 h). Dopamine levels were then estimated post injury by utilizing a commercially available ELISA method specific to DA. We found that DA levels were significantly reduced at 3 h, but there was no reduction at 6, 12 and 24 h in FPI groups when compared to the control and sham groups. Subjects receiving NBOT showed consistent increased DA levels at each time point when compared with Sham and FPI groups. These results suggest that FPI may alter DA levels at the early post-TBI stages but not in later stages. While DA levels increased in 6, 12 and 24 h in the FPI groups, NBOT could be used to accelerate the prevention of early dopaminergic neuronal damage following FPI injury and improve DA levels consistently.

Natural peste des petits ruminants virus infection in Black Bengal goats: virological, pathological and immunohistochemical investigation.

BACKGROUND: Peste des Petits Ruminants (PPR), also known as Goat Plague, occurs in goats, sheep and related species. It is caused by a morbillivirus in the family Paramyxoviridae. In Bangladesh PPR is endemic and it causes serious economic losses. Pathology of PPR has been reported in different goat and sheep breeds from natural and experimental infections. Field results are better indicators of pathogenicity of the circulating virus. The severity of the disease varies with species, breed and immune status of the host. Pathological investigations of natural outbreaks of PPR in Balck Bengal goats are very limited. The current investigation was aimed at describing pathology and antigen localization in natural PPR infections in Black Bengal goats. RESULTS: A total of 28 outbreaks were investigated clinically and virologically. Average flock morbidity and mortality were 75% and 59%, respectively, with case fatality rate of 74%. Necropsy was conducted on 21 goats from 15 outbreaks. The major gross lesions were congestion of gastrointestinal tract, pneumonia, engorged spleen, and oedematous lymphnodes. Histopathological examination revealed severe enteritis with denudation of intestinal epithelium, severe broncho-interstitial pneumonia with macrophages within lung alveoli and extensive haemorrhages with depletion of lymphoid cells and infiltration of macrophages in the sinuses of spleen. In lymph nodes, the cortical nodules were replaced by wide sinusoids with severe depletion of lymphocytes, infiltration of mononuclear cells and some giant cells in sub-capsular areas and medullary sinuses. PPR virus antigen was found in pneumocytes and alveolar macrophages in lungs. Viral RNA could be detected by RT-PCR in 69 out of 84 nasal swab, 59 out of 84 blood and 21 out of 21 lymph node samples. Sequence analyses revealed closeness of Bangladeshi strains with other recent Asian isolates. CONCLUSION: Natural outbreaks of PPR in Black Bengal goats in Bangladesh resulted in 75% and 59% flock morbidity and mortality, respectively, with a case fatality rate of 74%. The striking histo-morphologic diagnosis of PPR was acute pneumonia and severe gastro-enteritis. A detailed experimental pathological study on Black Bengal goats infected with recent isolates is required.

Age-dependent Electroencephalographic Differences in the Genetic Absence Epilepsy Rats from Strasbourg (GAERS) Model of Absence Epilepsy.

Genetic Absence Epilepsy Rats from Strasbourg (GAERS) are a prognostic genetic model of absence epilepsy. This model displays the electro-clinical, behavioural, and pharmacological features of absence seizures. Although GAERS share typical characteristics, including spike-and-wave discharges (SWDs) in the electroencephalography (EEG), age-dependent studies with these animals have not yet been reported. The aim of the present study is to perform a systematic comparison contrasting the SWDs of young and older GAERS, in terms of the number, duration, frequency, and waveform morphology of the discharges, as well as the pre-SWD EEG characteristics, using identical measurement and analysis techniques. The number, cumulative total duration and mean duration of SWDs were significantly higher in young GAERS (4 to 6 months) compared to older GAERS (12 to 14 months). Furthermore, the SWD spectra and average SWD waveforms indicated that a single cycle of the SWD contains more energy in faster components, such as increased spikes and higher power, in the SWDs of the young GAERS. Additionally, older GAERS showed weak amplitude spikes in SWDs and higher power pre-SWDs. These clear morphological differences in the EEGs of young and older GAERS rats should be further examined in future studies that explore new dimensions of genetic absence epilepsy.

Durvalumab-Induced Triple-M Syndrome.

Background: While the use of immunotherapy has revolutionised the treatment of various cancers, it is often associated with a myriad of immune-related adverse effects. Case Presentation: In this article, we report a rare case of durvalumab-induced triple-M syndrome in a 69-year-old woman with stage III lung adenocarcinoma. She was admitted with profound generalised muscle weakness, myalgia, and exertional breathlessness, about a week into her second cycle of durvalumab, an immune checkpoint inhibitor. She had clinicopathological features of myositis, myasthenia and myocarditis with acute onset symptomatic tri-fascicular block on electrocardiogram, requiring urgent cardiology intervention. Durvalumab was discontinued and she was treated with a combination of high-dose steroids and intravenous immunoglobulin after which she had clinical and biochemical improvement, albeit with residual muscle weakness. Conclusion: Myocarditis-myositis-myasthenia complex is a rare side effect of immunotherapy which has been reported in other immune checkpoint inhibitors, but less so with durvalumab. We report this clinical case to raise awareness of this rare and potentially life-threatening adverse effect of this agent. LEARNING POINTS: Triple-M syndrome is a rare immune-related adverse effect, which has been noted in other immune checkpoint inhibitors, but less so with durvalumab specifically.Immunotherapy-induced myositis, myocarditis and myasthenia can occur in isolation or, rarely, in association as a syndrome.This case demonstrates the potentially life-threatening nature of this entity, the need for early recognition, and multi-specialist teamwork to ensure good outcome.

Potassium augments growth, yield, nutrient content, and drought tolerance in mung bean (Vigna radiata L. Wilczek.).

Uneven rainfall and high temperature cause drought in tropical and subtropical regions which is a major challenge to cultivating summer mung bean. Potassium (K), a major essential nutrient of plants can alleviate water stress (WS) tolerance in plants. A field trial was executed under a rainout shelter with additional K fertilization including recommended K fertilizer (RKF) for relieving the harmful impact of drought in response to water use efficiency (WUE), growth, yield attributes, nutrient content, and yield of mung bean at the Regional Agricultural Research Station, BARI, Ishwardi, Pabna in two successive summer season of 2018 and 2019. Drought-tolerant genotype BMX-08010-2 (G1) and drought-susceptible cultivar BARI Mung-1 (G2) were grown by applying seven K fertilizer levels (KL) using a split-plot design with three replications, where mung bean genotypes were allotted in the main plots, and KL were assigned randomly in the sub-plots. A considerable variation was observed in the measured variables. Depending on the different applied KL and seed yield of mung bean, the water use efficiency (WUE) varied from 4.73 to 8.14 kg ha-1 mm-1. The treatment applying 125% more K with RKF (KL7) under WS gave the maximum WUE (8.14 kg ha-1 mm-1) obtaining a seed yield of 1093.60 kg ha-1. The treatment receiving only RKF under WS (KL2) provided the minimum WUE (4.73 kg ha-1 mm-1) attaining a seed yield of 825.17 kg ha-1. Results showed that various characteristics including nutrients (N, P, K, and S) content in stover and seed, total dry matter (TDM) in different growth stages, leaf area index (LAI), crop growth rate (CGR), root volume (RV), root density (RD), plant height, pod plant-1, pod length, seeds pod-1, seed weight, and seed yield in all pickings increased with increasing K levels, particularly noted with KL7. The highest grain yield (32.52%) was also obtained from KL7 compared to lower K with RKF. Overall, yield varied from 1410.37 kg ha-1 using 281 mm water (KL1; well-watered condition with RKF) to 825.17 kg ha-1 using 175 mm water (KL2). The results exhibited that the application of additional K improves the performance of all traits under WS conditions. Therefore, mung beans cultivating under WS requires additional K to diminish the negative effect of drought, and adequate use of K contributes to accomplishing sustainable productivity.

Phenotypic diversity in qualitative and quantitative traits for selection of high yield potential field pea genotypes.

Field pea (Pisum sativum L.) needs improvement to increase productivity due to its high price and demand. However, the incidence of powdery mildew (PM) disease limits its production. This study aimed to analyze the diversity of qualitative and quantitative traits against powdery mildew resistance by utilizing cluster and principal component analysis to explore PM resistance high-yield potential field peas. Shannon-Weaver's diversity index (H') displayed high intra-genotype diversity for quantitative and qualitative aspects. Heterogeneity was identified for resistance against powdery mildew infections. Eighty-five genotypes were divided into five groups using Mohalanobis generalized distance (D2) statistics. The highest inter-cluster D2 value was observed between clusters 2 and 3 (11.89) while the lowest value was found between clusters 3 and 4 (2.06). Most of the genotypes had noticeable differences, so these could be employed in a crossing scheme. Twelve genotypes were extremely resistant, 29 genotypes were resistant, 25 genotypes were moderately resistant, 18 genotypes were fairly susceptible, and 1 genotype was susceptible to powdery mildew disease. Among 29 resistant genotypes, BFP77, BFP74, BFP63, BFP62, BFP43, and BFP80 were high yielders and, could be used directly and/or transferred through hybridization to high-yielding disease-susceptible genotypes. Among the 25 moderately resistant genotypes, BFP78, BFP45, BFP79, and BFP48 were found to be high yielders. In principal component analysis (PCA), the first four PCs with Eigen values > 1 accounted for 88.4% variability for quantitative traits. Clustering sorted genotypes into five groups, where groups 1 to 5 assembled 37, 28, 1, 8, and 11 genotypes, respectively. Genotypes of cluster 4 were identified as high yielders with its attributes. Pearson correlation significantly and positively correlated across all traits except for PM. This variation suggested that there is a mechanism to select promising genotypes for field pea breeding. Considering all features, BFP78, BFP77, BFP74, BFP63, BFP62, BFP45, BFP79, and BFP80 could be preferred as high yielders and PM resistance owing to longer pod lengths, seeds per pod and pods per plant.

Surveillance of avian influenza virus type A in semi-scavenging ducks in Bangladesh.

BACKGROUND: Ducks are the natural reservoir of influenza A virus and the central host for highly pathogenic avian influenza (H5N1), while domestic ducks rearing in semi-scavenging system could serve as re-assortment vessels for re-emerging new subtypes of influenza viruses between birds to human. Avian influenza virus (AIV) surveillance in Bangladesh has been passive, relying on poultry farmers to report suspected outbreaks of highly pathogenic H5N1 influenza. Here, the results of an active surveillance effort focusing on the semi-scavenging ducks are presented. RESULT: A total of 2100 cloacal swabs and 2100 sera were collected from semi-scavenging ducks from three wintering-sites of Bangladesh during three successive winter seasons, December through February in the years between 2009 and 2012. Virus isolation and identification were carried out from the cloacal swabs by virus propagation in embryonated hen eggs followed by amplification of viral RNA using Avian influenza virus (AIV) specific RT-PCR. The overall prevalence of avian influenza type A was 22.05% for swab samples and 39.76% ducks were sero-positive for avian influenza type A antibody. Extremely low sero-prevalence (0.09%) of AIV H5N1 was detected. CONCLUSIONS: Based on our surveillance results, we conclude that semi-scavenging ducks in Bangladesh might play important role in transmitting Avian Influenza virus (AIV) type A. However, the current risk of infection for humans from domestic ducks in Bangladesh is negligible. We believe that this relatively large dataset over three winters in Bangladesh might create a strong foundation for future studies of AIV prevalence, evolution, and ecology in wintering sites around the globe.

Modulation of growth performance, gut morphometry, and cecal microbiota in broilers by clove (Syzygium aromaticum) and tulsi (Ocimum sanctum) supplementation.

In an epoch of the growing risk of antibiotic resistance, there is a dire need to establish an effective novel feeding practice for broiler nutrition as an alternative to antibiotics. Hence, the aim of the current study was to evaluate the impact of clove powder and tulsi extract on the growth performance, gut morphologic and morphometric indices, and cecal microbial status of broiler, as an alternative to antibiotic growth promoters (AGPs). Sixty day-old chicks of Cobb-500 strain were randomly divided into 4 groups, each having 15 birds. Chicks of the control group (T0) were fed commercial broiler feed with no additional supplementation. The treatment groups were offered commercial broiler feed and received clove powder and tulsi extract with drinking water at the rate of 0.5% + 2% (T1), 1% + 3% (T2), and 1.5% + 4% (T3), respectively. Results showed a nonlinear relationship with the dosage of clove and tulsi. All the growth parameters substantially (P < 0.05) improved in T2 while T1 and T3 showed no significant improvement compared to T0. The final body weight was significantly (P < 0.05) higher in T2. Giblet and offal weights showed no noticeable differences except in the intestine and heart where intestine weight markedly (P < 0.05) decreased in T3 and heart weight significantly (P < 0.05) increased in T1 and T2. Clove and tulsi supplementation substantially improved the villus height and villus surface area of the small intestine in T2 while the large intestine remained mostly unaffected by the treatment. Cecal microbial status significantly improved in all the treatment groups having increased (P < 0.05) Lactobacillus spp. count and decreased (P < 0.05) E. coli count compared to T0. Based on the aforementioned findings, it can be concluded that the combination of clove and tulsi can improve the growth performance and gut health of broilers which is largely dose-dependent and might be supplied as a potential alternative to AGPs.

Assessment of Heavy Metals Contamination and Antimicrobial Drugs Residue in Broiler Edible Tissues in Bangladesh.

There are substantial public health consequences when hazardous heavy metal contaminants and antimicrobial drug residues are present in broiler edible tissues. This study aimed to assess the concentration of antimicrobial drugs and heavy metals residues in broiler meat, bones and edible composites (combinations of liver, kidney and gizzard). Samples were collected from different types of broiler farms, broiler wet meat markets and supermarkets, covering all five divisions of Bangladesh. The antimicrobial drug and heavy metal residues were analyzed by uHPLC and ICP-MS, respectively. In addition, a cross-sectional survey was conducted among broiler meat consumers in the study areas to evaluate their attitude towards the consumption of broiler meat. The survey clearly stated that broiler meat consumers in Bangladesh have a negative attitude toward the consumption of broiler meat, although all respondents reported to eat broiler meat regularly. The antibiotic with the highest prevalence of residues in broiler edible tissues was oxytetracycline, followed by doxycycline, sulphadiazine and chloramphenicol. On the other hand, all collected broiler edible tissues contained chromium and lead, followed by arsenic. The fact of the matter is that the antimicrobial drugs and heavy metals residues were found to be below the maximum residue limit (MRL), except for the lead content. In addition, the broiler meat samples from supermarkets had lower levels of antimicrobial drugs and heavy metals residue compared to the broiler meat collected from various types of farms and broiler wet meat markets. Irrespective of the source, broiler meat was found to contain antimicrobial drugs and heavy metals residues below the MRL, except for lead, suggesting that broiler meat is safe for human consumption. Therefore, raising public awareness regarding misconceptions about broiler meat consumption among consumers would be warranted.