Biology subjects

Hasan, M. R.

Publications and source records attributed to Hasan, M. R..

16 recordsLinked to original sources

bioRxiv2026

Probabilistic dietary exposure modeling and health risk assessment of heavy metals via the fodder-cattle-human continuum in Bangladesh

Dietary exposure to heavy metals (HMs) via animal-source foods is a critical environmental health pathway. In rapidly industrializing Bangladesh, contamination of the bovine food chain from agricultural feeds and industrial emissions poses an unquantified public health burden. This study evaluated exposure pathways, spatial distribution, mass-transfer dynamics, and health risks of six HMs (Cr, Cu, Cd, Pb, As, and Hg) across the fodder-cattle-human continuum. Samples of beef (n = 76), raw milk (n = 76), commercial cattle feed (n = 40), and fodder (n = 88) were collected from eight sites across industrial and non-industrial zones in Bangladesh and analysed by atomic absorption spectroscopy. Probabilistic Monte Carlo simulations (10,000 iterations) quantified estimated daily intake, target hazard quotients (THQ), cumulative hazard index (HI), and lifetime carcinogenic risk (CR) for adult and pediatric receptors. Copper (Cu) was the dominant contaminant across all matrices, peaking in beef (103.89 {+/-} 15.87 mg/kg) and milk (13.67 {+/-} 1.53 mg/L). Spatial analysis revealed distinct contamination profiles: Pb burden peaked in industrial zones while Cr was elevated in non-industrial sectors. Monte Carlo modelling identified commercial feed as the most efficient transfer vector into beef. Pediatric THQ for Cu significantly exceeded the safety threshold (THQ > 1), and upper-bound lifetime carcinogenic risk from As approached the critical USEPA 10- regulatory ceiling. These findings demonstrate that industrial and agricultural externalities efficiently contaminate the bovine food supply chain in Bangladesh, with copper and arsenic representing the most critical non-carcinogenic and carcinogenic dietary hazards, respectively. Children are disproportionately vulnerable due to lower body weight. The results underscore the need for targeted upstream interventions in commercial feed production and provide evidence to support feed-quality regulation and environmental monitoring in rapidly industrializing settings.

pharmacology and toxicology↗

bioRxiv2025

Bacillus subtilis reprograms host transcriptome and rhizosphere microbiome via systemic signaling to confer alkaline stress tolerance in garden pea

Soil alkalinity severely limits legume growth, but the role of Bacillus subtilis in alkaline stress tolerance remains unclear in garden pea. We found that multiple garden pea genotypes inoculated with B. subtilis under alkaline stress showed host-specific improvements in growth parameters. Mechanistic analysis conducted on Sugar Snap showed improved nodulation, mineral status, and photosystem efficiency, while split-root assays showed responses consistent with systemic effects of B. subtilis in alkaline tolerance. Further, FeEDDHA partially reduced alkaline stress symptoms but did not fully restore nodulation. In contrast, B. subtilis increased rhizosphere Fe-chelating activity and improved nodulation, leading to stronger symbiotic recovery than inorganic Fe alone. This suggests that factors associated with B. subtilis inoculation, beyond Fe availability alone, may contribute to the observed recovery of nodulation. This is further supported by in vitro co-culture experiments showing enhanced growth of R. leguminosarum in the presence of B. subtilis under alkaline conditions, indicating potential microbial compatibility for coping with stress. RNA-seq analysis identified 958 upregulated and 1,134 downregulated genes in roots inoculated with B. subtilis under alkaline conditions. The upregulated genes were mostly involved in the sugar-mediated symbiotic association (SWEET and GLUT), pH homeostasis (cation/H+ exchanger and ATPase), and nutrient assimilation (Ammonium transporter and Zn/Fe permease). Microbial community analysis revealed that B. subtilis significantly altered bacterial alpha diversity under alkaline stress, whereas fungal alpha diversity remained unaffected. Further, B. subtilis reshaped the rhizosphere microbial community and enriched taxa such as Pseudomonas, Pseudorhizobium, and Chaetomium, which were potentially associated with responses to alkaline stress. Taken together, microbial interventions such as B. subtilis offer an effective strategy to boost legume tolerance to alkaline soils.

plant biology↗

bioRxiv2025

Identification of Bone Morphogenic Protein (BMP15) gene at exons 1 and 2 in Indigenous, Mozaffornagri, and Dorper ram breeds of Bangladesh and its phylogenetic relationship with other breeds

Sheep play a vital role in alleviating poverty and providing protein for the people of Bangladesh and they are popular for their mutton production. This study aimed to explore the polymorphisms in the BMP15 gene among various Bangladeshi ram breeds for devising genetic improvement strategies to boost mutton output and help reduce poverty. We collected blood samples from 25 rams, including the Indigenous, Mozaffarnagri, and Dorper breeds, all raised in a traditional farming system. After extracting DNA, we amplified the BMP15 gene at Exon-1 and Exon-2 using specific primer pairs. We used Sanger sequencing to sequence the amplified fragments at the Exon-1 end. A highly accurate method with a 99.99% success rate. The sequences were then aligned with the NCBI GenBank database and analyzed using BioEdit 6.0 and MEGA 12.0 software. Our findings confirmed that the BMP15 gene is present in all the breeds we studied, but we didnt find any polymorphisms among the Bangladeshi rams. The phylogenetic analysis showed strong genetic connections between local and international breeds. These results suggest the potential for enhancing Indigenous sheep through male-line genetic manipulation techniques, like selective semen use or artificial insemination, while preserving the BMP15 sequences to improve their productive traits.

cell biology↗

bioRxiv2025

Future flooding tolerant rice germplasm: resilience afforded beyond Sub1A gene

Developing high-yielding, flood-tolerant rice varieties is essential for enhancing productivity and livelihoods in flood-prone ecologies. We explored genetic avenues beyond the well-known SUB1A gene to improve flood resilience in rice. We screened a collection of 6,274 elite genotypes from IRRIs germplasm repository for submergence and stagnant flooding tolerance over multiple seasons and years. This rigorous screening identified 89 outstanding elite genotypes, among which thirty-seven exhibited high submergence tolerance, surpassing the survival rate of SUB1A introgression genotypes by 40-50%. Thirty-five genotypes showed significant tolerance to stagnant flooding, and 17 demonstrated dual tolerance capabilities, highlighting their adaptability to varying flood conditions. The genotypes identified have a broader genetic diversity and harbor 86 key QTLs and genes related to traits such as grain quality, grain yield, herbicide resistance, and various biotic and abiotic traits, highlighting the richness of the identified elite collection. Besides germplasm, we introduce an innovative breeding approach called Transition from Trait to Environment (TTE). TTE leverages a parental pool of high-performing genotypes with complete submergence tolerance to drive population improvement and enable genomic selection in the flood breeding program. Our approach of TTE achieved a remarkable 65% increase in genetic gain for submergence tolerance, with the resulting fixed breeding genotypes demonstrating exceptional performance in flood-prone environments of India and Bangladesh. The elite genotypes identified herein represent invaluable genetic resources for the global rice research community. By adopting the TTE approach, which is trait agonistic, we establish a robust framework for developing more resilient genotypes using advanced breeding tools. Plain Language SummaryTo address climate challenges, an urgent focus is necessary to identify and develop flood-tolerant rice varieties, particularly for flood-prone ecosystems across Asia and Africa. We screened 6,274 elite genotypes from IRRIs germplasm and identified 89 promising lines with improved tolerance to submergence and stagnant flooding. Among these, 37 demonstrated 40-50% greater submergence tolerance than SUB1A introgression lines, 35 exhibited stagnant flooding tolerance, and 17 showed dual tolerance. These genotypes contain 86 key QTLs and genes associated with yield, grain quality, and biotic and abiotic tolerance traits. A new breeding strategy, the Transition from Trait to Environment (TTE) approach, was developed. We achieved a genetic gain of 65% for submergence tolerance in rice using this method. The newly identified germplasm provides invaluable genetic resources for the global rice research community to develop flood-tolerant rice genotypes. Core ideas The SUB1A gene, enabling rice to survive underwater for 14 days, marked a significant breakthrough. We have identified elite genotypes with submergence tolerance significantly surpassing the SUB1A gene-mediated tolerance. The diverse elite genotypes identified harbor 86 key genes and QTLs that affect various traits positively. Developed a unique breeding strategy for implementing population improvement in challenging environments. The new breeding strategy demonstrated a genetic gain of 65% for submergence tolerance.

plant biology↗

bioRxiv2025

Iron retention coupled with trade-offs in localized symbiotic effects confers tolerance to combined iron deficiency and drought in soybean

Iron (Fe) and water availability are closely interlinked, with deficiencies in both adversely affecting soybean growth. However, the strategies employed by soybean to tolerate such conditions remain poorly understood. This study elucidates the interactions of host factors, and microbial associations using multi-omics approaches in Clark (tolerant) and Arisoy (sensitive) genotypes exposed to Fe deficiency and drought. Clark exhibited resilience to stress through sustained osmotic regulation, nutrient uptake, and photosynthetic activity, in contrast to Arisoy. Particularly, Fe retention in Clark, accompanied by the upregulation of ferritin-like proteins, may mitigate oxidative stress by reducing Fenton reactions. Furthermore, higher jasmonic and salicylic acid levels in Clark may contribute to its enhanced stress adaptation compared to Arisoy. RNA-seq analysis revealed 818 and 500 upregulated, along with 931 and 361 downregulated genes, in the roots of Clark and Arisoy, respectively, under stress. We observed the upregulation of symbiotic genes, such as Chalcone-flavonone isomerase 1 and SWEET10, accompanied by increased rhizosphere siderophore and root flavonoid in Clark. This indicates a significant role of microbes in mediating differential stress tolerance in soybean. Particularly, the combined stress led to distinct root and nodule microbiome dynamics, with Clark recruiting beneficial microbes such as Variovorax and Paecilomyces, whereas Arisoy exhibited the opposite pattern. In addition, Clark maintained nodule Bradyrhizobium and tissue nitrogen status, supported by ammonium retention and induction of Ammonium transporter 1 in the roots. Furthermore, in vitro compatibility between V. paradoxus and P. lilacinus suggests a synergistic interaction, with their localized signals benefiting Clark. Remarkably, enriched microbiomes significantly improved growth parameters, accompanied by elevated rhizosphere siderophore in sensitive genotypes under stress. This study is the first to uncover mechanisms of dual stress tolerance in soybean that may offer promising targets for breeding programs and microbiome-based biofertilizer strategies to improve combined stress tolerance in soybean and other legumes. HighlightIron retention coupled with symbiotic associations driven by the enrichment of Variovorax and Paecilomyces in the roots confers tolerance to combined iron deficiency and drought in soybean.

plant biology↗

bioRxiv2024

Transcriptional Responses and Microbiome Shifts in Pea Roots Under High pH Stress

High soil pH severely impacts plant growth and productivity, yet the transcriptomic changes and microbial dynamics underlying stress adaptation in garden pea (Pisum sativum ssp. hortense) remain unclear. This study demonstrates that high soil pH leads to stunted growth, reduced biomass, impaired photosynthesis, and nutrient status in garden pea. Further, disruption in key nitrogen-fixing bacteria (Rhizobium indicum, R. leguminosarum, and R. redzepovicii), along with the downregulation of NifA and NifD genes and upregulation of NifH in nodules highlight the critical role of micronutrient balance in legume-microbe symbiosis and a compensatory response to maintain nitrogen status. RNA-seq analysis revealed extensive transcriptional reprogramming in roots, characterized by the upregulation of oxidative stress response genes (e.g., oxidoreductase and glutathione transferase activities, metal ion transporters) and the downregulation of genes related to ammonia-lyase activity and ion binding, reflecting broader disruptions in nutrient homeostasis. KEGG pathway analysis identified enrichment of MAPK signaling pathway, likely interacting with other pathways associated with stress tolerance, metabolic adjustment, and structural reorganization as part of adaptive responses to high pH. Root microbiome analysis showed significant enrichment of Variovorax, Shinella, and Chaetomium, suggesting host-driven recruitment under high pH stress. Stable genera such as Pseudomonas, Novosphingobium, Mycobacterium, Herbaspirillum, and Paecilomyces displayed resilience to stress conditions, potentially forming core microbiome components for adaptation to high pH. In a targeted study, inoculation of plants with an enriched microbiome, particularly C. globosum, under high pH conditions improved growth parameters and increased the abundance of Stenotrophomonas and Pseudomonas in the roots. It suggests that these bacterial genera may act as helper microbes to C. globosum, collectively promoting stress resilience in pea suffering from high pH. These findings provide a foundation for microbiome-aided breeding programs and the development of microbial consortia to enhance the adaptation of pea plants to high pH conditions.

plant biology↗

bioRxiv2024

Fe deficiency causes transcriptional shift in roots leading to disruption of drought tolerance in soybean

Soil alkalinity and drought collectively cause severe growth retardation in crops. However, the adaptive responses and transcriptional changes under such conditions remain unclear in soybean. In this growth incubator study, soil alkalinity and drought stress led to significant reductions in plant biomass, chlorophyll, and nutrient uptake in soybean. However, the photochemical efficiency of photosystem II remained stable, suggesting the activation of protective mechanisms to maintain photosynthetic functions. RNA-seq analysis demonstrated 357 upregulated and 799 downregulated genes in roots due to combined soil alkalinity and drought. Analysis revealed a complex response, with upregulation of genes predominantly involved in mineral homeostasis (Iron dehydrogenase, Sulfurylase), reactive oxygen species scavenging (Glutamate synthase, L-Ascorbate peroxidase) and hormonal signaling. Particularly, several ethylene-responsive genes, including the Transcription factors TF5 and TF018, were upregulated, indicating the activation of stress-related signaling pathways. In a targeted study, plants supplemented with an ethylene precursor showed significant improvements in morpho-physiological traits and Fe status under combined stress. However, ethylene precursor applied in non-stressed plants led to reduced growth, and Fe levels, suggesting an involvement of the context-dependent role of ethylene in promoting stress tolerance. Furthermore, ethylene precursors caused an increase in root flavonoid and rhizosphere siderophore while restoring bacterial and fungal microbial cells in roots under combined stress in soil. However, in healthy plants, flavonoid and siderophore levels decreased, accompanied by a reduction in microbial cells to control levels. This suggests that elevated ethylene may regulate root exudates to recruit microbes dominated by host response, aiding soybean plants cope with combined stresses, although this effect may not occur in non-stressed plants. This is the first report on the transcriptional response and physiological adjustments in soybean exposed to alkalinity and drought, potentially advancing knowledge for genetic and agronomic interventions to improve stress resilience in legume crops.

plant biology↗

bioRxiv2024

Machine Learning to Predict Gut Microbiomes of Agricultural Pests

ContextWhile current efforts to control agricultural insect pests largely focus on the widespread use of insecticides, predicting microbiome composition can provide important data for creating more efficient and long-lasting pest control methods by analysing the pests food-digesting capacity and resistance to bacteria or viruses. AimsInstead of using computationally expensive techniques, we aim to investigate the dynamics of these microbiome compositions using metagenomic samples taken from fruit flies. MethodsIn this paper, we propose the three machine learning-based biological models. Firstly, we propose the intrafamilial successor prediction, which predicts the relative abundance of each bacterial family using the past four generations. Next, we propose our interfamilial quantitative prediction, where the model predicts the amount of a given bacterial family in each sample using the amount of all other bacteria present in the sample. Lastly. we propose our interfamilial qualitative prediction, which predicts the relative abundance of each bacterial family within a sample using binary information of all bacterial families. Key ResultsAll three models were tested against Least Angle Regression, Random Forest, Elastic-Net, and Lasso. The third approach exhibits promising results by applying a Random Forest with the lowest mean Coefficient of Variance of 1.25. ConclusionThe overall results of this study highlight how complex these dynamic systems are and demonstrate that more computationally efficient methods can characterise them quickly.

bioinformatics↗

bioRxiv2024

Trichoderma afroharzianum induces rhizobia and flavonoid through systemic signaling to combat iron deficiency in garden pea

Iron (Fe) deficiency is a limiting factor for legumes, yet the role of beneficial fungi in mitigating Fe deficiency in garden pea is understudied. In this study, Trichoderma afroharzianum T22 colonized the roots of garden pea cultivars exposed to alkaline-exposed Fe-deficiency in a host-specific manner. In Fe-deficient Sugar Snap, T22 improved growth parameters, consistent with increased tissue mineral content, particularly Fe and Mn, as well as enhanced rhizosphere siderophore levels. The split-root assay demonstrated that the beneficial effects of T22 on Fe deficiency mitigation are the result of a whole-plant association rather than localized root-specific effects. RNA-seq analysis showed 575 and 818 differentially expressed genes upregulated and downregulated in the roots inoculated with T22 under Fe deficiency. The upregulated genes were mostly involved in the flavonoid biosynthetic pathway (monooxygenase activity, ammonia-lyase activity, 4-coumarate-CoA ligase), along with genes related to mineral transport and redox homeostasis. Further, a flavonoid precursor restored plant health even in the absence of T22, confirming the role of microbial symbiosis in mitigating Fe deficiency. Interestingly, T22 restored the abundance of rhizobia, particularly Rhizobium leguminosarum and Rhizobium indicum, along with the induction of NifA, NifD, and NifH in nodules, suggesting a connection between T22 and rhizobia under Fe-starvation. Further, the elevated rhizosphere siderophore, root flavonoid, expression of PsCoA (4-coumarate-CoA ligase) as well as the relative abundance of TaAOX1 and R. leguminosarum diminished when T22 was substituted with exogenous Fe. This suggests that exogenous Fe eliminates the need for microbiome-driven Fe mobilization, while T22-mediated Fe mitigation depends on flavonoid-driven symbiosis and R. leguminosarum abundance. It was further supported by the positive interaction of T22 on R. leguminosarum growth in Fe-deficient media. Thus, the beneficial effect of T22 on rhizobia likely stems from their interactions, not just improved Fe status in plants. This study provides the first mechanistic insights into T22 interactions with host and rhizobia, advancing microbiome strategies to alleviate Fe deficiency in peas and other legumes.

plant biology↗

bioRxiv2023

Identification of Natural Antiviral Drug Candidates Against Tilapia Lake Virus: Computational Drug Design Approaches

Tilapia Lake Virus (TiLV) is a disease that affects tilapia fish, causing a high rate of sudden death at any stage of their growth. Unfortunately, there are currently no effective antiviral drugs or vaccines to control the progression of this disease. Researchers have discovered that the CRM1 protein plays a critical function in the development and spreading of animal viruses. By inhibiting CRM1, the viruss spread in commercial fish farms can be suppressed. With this in mind, this study intended to identify potential antiviral drugs from two different tropical mangrove plants from tropical regions: Heritiera fomes and Ceriops candolleana. To identify promising compounds that target the CRM1 protein, a computer-aided drug discovery approach is employed containing molecular docking, ADME (absorption, distribution, metabolism and excretion) analysis, toxicity assessment as well as molecular dynamics (MD) simulation. To estimate binding affinities of all phytochemicals, molecular docking is used and the top three candidate compounds with the highest docking scores were selected, which are CID107876 (-8.3), CID12795736 (-8.2), and CID12303662 (-7.9). We also evaluated the ADME and toxicity properties of these compounds. Finally, molecular dynamics simulation was conducted to analyze the stability of the protein-ligand complex structures and confirm the suitability of these compounds. The computational study demonstrated that the phytochemicals found in H. fomes and C. candolleana could potentially serve as important inhibitors of TiLV, offering practical utility. However, further in vivo investigations are necessary to investigate the effectiveness of these compounds as antiviral drugs against the virus TiLV.

pharmacology and toxicology↗

bioRxiv2023

Seroprevalence of IgG Antibody against SARS-CoV-2 Nucleocapsid protein and Associated Risk Factors

Estimation of antibody development against SARS-CoV-2 is essential means for understanding the immune response against the virus. We reported IgG antibody development status against Nucleocapsid protein of the virus and compared with lifestyle (health and food habits), co-existing diseases, vaccination and COVID-19 infection status. ELISA (Enzyme Linked Immunosorbent Assay) was performed to assess IgG antibodies targeted against the Nucleocapsid protein of SARS-CoV-2 in participants (n=500). In this seroprevalence study, serological data were estimated for a period of 10 months in the participants who were aged 10 years and above. Sociodemographic and risk factors related data were collected through a written questionnaire and chi-square test was performed to determine the association with seropositivity. The overall seroprevalence of anti-SARS-CoV-2 antibodies among the study subjects was 47.8%. Estimates were highest among the participants of 21-40 years old (55.1%), and lowest in older aged (>60 years) participants (39.5%). Among the Sinopharm vaccinated individuals 81.8% had developed anti-Nucleocapsid antibody. Physical exercise and existence of comorbidities like hypertension and diabetes were the distinguishing factors between seropositive and seronegative individuals. Seropositivity rate largely varied among symptomatic (67%) and asymptomatic (33.1%) COVID-19 infected participants. The findings suggest that residents of Dhaka city had a higher prevalence of anti-nucleocapsid antibody in the second year of the pandemic. This indicates the improvement of immunological status among the population. Finally, the study emphasizes on maintaining active and healthy lifestyle to improve immunity. However, the absence of IgG antibodies in many cases of COVID-19 infected individuals suggests that antibodies wane with time. Key messagesO_LIThe overall seroprevalence of anti-Nucleocapsid IgG among the study subjects was determined to be 47.8%. C_LIO_LIAge, regular physical exercise, existence of comorbidities were the identified parameters associated with seroprevalence. C_LIO_LIThis study observed lower prevalence of Anti-Nucleocapsid antibody among asymptomatic cases of COVID-19 infected individuals compared to symptomatic cases. C_LI

immunology↗

bioRxiv2020

Virome-wide serological profiling reveals association of herpesviruses with obesity

The relationship between viral infection and obesity has been known for several decades but epidemiological data related to obesity is limited to only a few viral pathogens. To identify associations between viral infections and obesity, a high-throughput virome-wide serological profiling tool, VirScan, was used to measure antibody responses to a wide range of viruses. Serum specimens from 457 Qatari adults (lean=184;obese=273) and 231 Qatari children (lean=111;obese=120) were assessed by VirScan. Pediatric specimens were simultaneously tested by conventional serology for several herpesviruses to validate VirScan results. Viral association with obesity was determined by calculation of odds ratio (OR) and p-values from Fisher test, and by multivariate regression analysis to adjust for age and gender, with Bonferroni correction for multiple testing. Comprehensive serological profiling of Qatari adult population with VirScan revealed positive and negative associations (p<0.05) of antibody responses to members of Herpesviridae and Picornaviridae families, respectively, with obesity. After adjusting p-values for multiple comparisons, only herpes simplex virus 1 (HSV-1) and Rhinovirus A were positively (OR=3.3; 95%CI 2.15-4.99; p=2.787E-08) and negatively (OR=0.4; 95%CI 0.26-0.65; p=1.175E-03) associated with obesity. At the peptide level, higher prevalence of antibodies against several peptide epitopes of HSV-1/2 was positively (OR=2.35-3.82; p[≤]3.981E-05) associated with obesity. No such associations were seen at the species or peptide levels in the pediatric population. By multivariate regression analysis, HSV-1 was independently associated with obesity irrespective of age and gender. These findings are in agreement with limited data on the adipogenic properties of HSV-1 observed in vitro. ImportanceThe state of Qatar has one of the highest rates of obesity and associated morbidities in the world. Although obesity is predominantly caused by the intake of high calorie diet and reduced physical activities, other factors including infections with certain viruses have been reported. Among these viruses, human adenoviruses were widely studied but epidemiological data for other viruses in relation to human obesity are limited. Here, we studied the association of obesity in Qatari adults and children with a wide range of viral pathogens using VirScan, a virome-wide serological profiling tool. Our results indicate significant association HSV-1 with obesity in the adult population only. Furthermore, we have identified a set of HSV peptides as candidate obesogenic factors for future studies.

microbiology↗

bioRxiv2020

Endemic human coronaviruses induce distinct antibody repertoires in adults and children

Four endemic human coronaviruses (HCoVs) are commonly associated with acute respiratory infection in humans. B cell responses to these "common cold" viruses remain incompletely understood. Here we report a comprehensive analysis of CoV-specific antibody repertoires in 231 children and 1168 adults using phage-immunoprecipitation sequencing. Seroprevalence of antibodies to endemic HCoVs ranged between ~4 and 27% depending on the species and cohort. We identified at least 136 novel linear B cell epitopes. Antibody repertoires against endemic HCoVs were qualitatively different between children and adults in that anti-HCoV IgG specificities more frequently found among children targeted functionally important and structurally conserved regions of the spike, nucleocapsid and matrix proteins. Moreover, antibody specificities targeting the highly conserved fusion peptide region and S2 cleavage site of the spike protein were broadly cross-reactive with peptides of epidemic human and non-human coronaviruses. In contrast, an acidic tandem repeat in the N-terminal region of the Nsp3 subdomain of the HCoV-HKU1 polyprotein was the predominant target of antibody responses in adult donors. Our findings shed light on the dominant species-specific and pan-CoV target sites of human antibody responses to coronavirus infection, thereby providing important insights for the development of prophylactic or therapeutic monoclonal antibodies and vaccine design.

immunology↗

bioRxiv2020

Isolation and characterization of two bacterial strains from textile effluents having Malachite Green dye degradation ability

Water pollution from textile effluent is now one of the major issues all over the world. Malachite Green dye of the triphenylmethane group is a key component of textile effluents. This study aimed to isolate and identify potential Malachite Green dye degrading bacteria from textile effluents. Different growth and culture parameters such as temperature, pH, inoculum-size and dye concentration were optimized to perform the dye-degradation assay using different concentrations of Malachite Green dye in mineral salt medium. A photo-electric-colorimeter was used to measure the decolorizing activity of bacteria at different time intervals after aerobic incubation. Two competent bacterial strains of Enterobacter spp. (CV-S1 and CM-S1) were isolated from textile effluents showing potential degradation efficiency against Malachite Green dye. The RAPD analysis and 16S rRNA sequencing confirmed the genetical difference of the isolated strains Enterobacter sp. CV-S1 and Enterobacter sp. CM-S1. The two bacterial strains CV-S1 and CM-S1 showed complete Malachite Green dye degradation up to 15 mg/l under shaking condition with 5% (v/v) inoculums at pH 6.50 and temperature 35{degrees}C within 72 and 144 hours respectively. These findings indicate that the two potential bacterial strains can be used in large scale treatment of textile effluents in the future.

microbiology↗

bioRxiv2019

A Metagenomics - Based Diagnostic Approach for Central Nervous System Infections in Hospital Acute Care Setting

The etiology of central nervous system (CNS) infections such as meningitis and encephalitis remains unknown in a large proportion of cases partly because the diversity of pathogens that may cause CNS infections greatly outnumber available test methods. Here we present a metagenomic next generation sequencing (mNGS) based approach for broad-range detection of pathogens associated with CNS infections, which is suitable for application in the acute care hospital setting. Using an Illumina MiSeq benchtop sequencer and the IDseq pipeline for identifying pathogens in metagenomic sequence data, we show that the analytical sensitivity of mNGS to detect pathogens is comparable to that of PCR in simulated cerebrospinal fluid (CSF) specimens. We then applied this method for pathogen detection in 74 CSF specimens from patients with suspected CNS infections that were previously tested by culture and/or PCR. Diagnostic accuracy, sensitivity and specificity of mNGS approach with reference to conventional methods were all 95%. Furthermore, confirmatory testing on specimens that gave discrepant results were mostly in favor of the mNGS assay. The clinical application of mNGS holds promise to benefit patients with CNS infections of unknown etiology.

pathology↗

bioRxiv2018

A novel real-time PCR assay panel for detection of common respiratory pathogens in a convenient, strip-tube array format

Commercial multiplex assays, built on different chemistries and platforms are widely available for simultaneous detection of pathogens that cause respiratory infections. However, these tests are often difficult to implement in a resource limited setting because of high cost. In this study, we developed and validated a method for simultaneous testing of common respiratory pathogens (Respanel) by real-time PCR in a convenient, strip-tube array format. Primers and probes for sixteen PCR assays were selected from the literature or newly designed. Following optimization of individual PCR assays, strip-tube arrays were prepared by dispensing primer-probe mixes (PPM) into two sets of 8-tube strips. Nucleic acid extracts from specimens were mixed with PCR master mix, and dispensed column-wise into 2X8-wells of a 96-well plate. PPMs from strip-tubes were then added to the wells using a multichannel pipette for real-time PCR. Individual PCR assays were optimized using previously known specimens (n=397) with 91%-100% concordance with culture, DFA or PCR results. Respanel was then tested in a routine manner at two different sites using specimens (n=147) previously tested by Qiagen Resplex I&II or Fast-Track Diagnostics Respiratory Pathogens 21 assays. The sensitivity, specificity and accuracy of Respanel were 94%, 95% and 95%, respectively, against Resplex and 88%, 100% and 99%, respectively, against FTDRP21. Respanel detected 48% more pathogens (p<0.05) than Resplex but the rate of pathogen detection was not significantly different from FTDRP21. Respanel is a convenient and inexpensive assay that is more sensitive than Resplex and comparable to FTDRP21 for the detection of common respiratory pathogens.

pathology↗