Pathomorphology, immunohistochemical, and molecular detection of an atypical porcine dermatitis and nephropathy syndrome (PDNS) due to PCV-2d-2 in naturally affected grower pigs of India.

Porcine circovirus type 2 (PCV-2) is of great economic significance to porcine industry worldwide. PCV-2 variants and genotypes, alternating world over, are the etiological agent of several clinical syndromes such as porcine dermatitis and nephropathy syndrome (PDNS), post-weaning multi-systemic wasting syndrome (PMWS) and others in pigs. This study is reporting an atypical manifestation of PDNS in twelve grower pigs, 3- to - 4.5 months age and either sex, died of the disease, with predominant lesions of nephropathy and no obvious clinical lesions in skin. Necropsy examination of pigs showed lesions of petechial -to- ecchymotic hemorrhages in the kidneys and in the right auricular musculature of the hearts. Microscopic lesions in H & E sections of the kidneys showed acute glomerulonephritis, interstitial nephritis, and vasculitis, but the skin morphology and architecture remained unaltered in contrast to the pathognomonic lesions of PDNS described in the literature. Other syndromic associations of PDNS in these cases included-perimyocarditis, interstitial pneumonia, depleted lymphoid tissues, tonsillitis, enteritis, and meningo-encephalitis. The lesional sites in duplicate paraffin tissue sections of kidneys, heart, lungs, spleen, lymph nodes, intestine, and brain demonstrated PCV-2 antigen in the cytoplasm of cells as highlighted by the intense immunolabeling on IHC staining. The PCV-2 positive organs reconfirmed by PCR, targeting ORF2 gene, which yielded 481bp size of products. The sequencing results of 481bp products on phylogenetic analysis showed 94% similarity with that of PCV-2 sequences in the database that grouped into PCV2d-2 genotype. The present report confirms, probably for the first time, the atypical PDNS cases due to PCV2d-2 genotype in naturally affected grower pigs of India.

MERS-CoV: epidemiology, molecular dynamics, therapeutics, and future challenges.

The Severe Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has gained research attention worldwide, given the current pandemic. Nevertheless, a previous zoonotic and highly pathogenic coronavirus, the Middle East Respiratory Syndrome coronavirus (MERS-CoV), is still causing concern, especially in Saudi Arabia and neighbour countries. The MERS-CoV has been reported from respiratory samples in more than 27 countries, and around 2500 cases have been reported with an approximate fatality rate of 35%. After its emergence in 2012 intermittent, sporadic cases, nosocomial infections and many community clusters of MERS continued to occur in many countries. Human-to-human transmission resulted in the large outbreaks in Saudi Arabia. The inherent genetic variability among various clads of the MERS-CoV might have probably paved the events of cross-species transmission along with changes in the inter-species and intra-species tropism. The current review is drafted using an extensive review of literature on various databases, selecting of publications irrespective of favouring or opposing, assessing the merit of study, the abstraction of data and analysing data. The genome of MERS-CoV contains around thirty thousand nucleotides having seven predicted open reading frames. Spike (S), envelope (E), membrane (M), and nucleocapsid (N) proteins are the four main structural proteins. The surface located spike protein (S) of betacoronaviruses has been established to be one of the significant factors in their zoonotic transmission through virus-receptor recognition mediation and subsequent initiation of viral infection. Three regions in Saudi Arabia (KSA), Eastern Province, Riyadh and Makkah were affected severely. The epidemic progression had been the highest in 2014 in Makkah and Riyadh and Eastern Province in 2013. With a lurking epidemic scare, there is a crucial need for effective therapeutic and immunological remedies constructed on sound molecular investigations.

Physiological implications of COVID-19 in reproduction: angiotensin-converting enzyme 2 a key player.

The COVID-19 outbreak, caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), was first identified in China, and it has quickly become a global threat to public health due to its rapid rate of transmission and fatalities. Angiotensin-converting enzyme 2 (ACE2) has been identified as a receptor that mediates the entry of SARS-CoV-2 into human cells, as in the case of severe acute respiratory syndrome coronavirus (SARS-CoV). Several studies have reported that ACE2 expression is higher in Leydig, Sertoli and seminiferous ductal cells of males, as well as in ovarian follicle cells of females, suggesting possible potential pathogenicity of the coronavirus in the reproductive system. Higher ACE2 expression in the human placenta and reports of vertical transmission of SARS-CoV-2 among clinical cases have increased the relevance of further studies in this area. This review focuses on the interaction between SARS-CoV-2 and the ACE2 receptor and speculates on the mechanistic interplay in association with male and female reproductive physiology. In addition, based on the available literature, we discuss the alleged sex differences in terms of the infectivity of SARS-CoV-2, which is claimed greater among males, and further explore the physiological role of ACE2 and 17ß-oestradiol for the same.

SARS-CoV-2/COVID-19 and advances in developing potential therapeutics and vaccines to counter this emerging pandemic.

A novel coronavirus (SARS-CoV-2), causing an emerging coronavirus disease (COVID-19), first detected in Wuhan City, Hubei Province, China, which has taken a catastrophic turn with high toll rates in China and subsequently spreading across the globe. The rapid spread of this virus to more than 210 countries while affecting more than 25 million people and causing more than 843,000 human deaths, it has resulted in a pandemic situation in the world. The SARS-CoV-2 virus belongs to the genus Betacoronavirus, like MERS-CoV and SARS-CoV, all of which originated in bats. It is highly contagious, causing symptoms like fever, dyspnea, asthenia and pneumonia, thrombocytopenia, and the severely infected patients succumb to the disease. Coronaviruses (CoVs) among all known RNA viruses have the largest genomes ranging from 26 to 32 kb in length. Extensive research has been conducted to understand the molecular basis of the SARS-CoV-2 infection and evolution, develop effective therapeutics, antiviral drugs, and vaccines, and to design rapid and confirmatory viral diagnostics as well as adopt appropriate prevention and control strategies. To date, August 30, 2020, no effective, proven therapeutic antibodies or specific drugs, and vaccines have turned up. In this review article, we describe the underlying molecular organization and phylogenetic analysis of the coronaviruses, including the SARS-CoV-2, and recent advances in diagnosis and vaccine development in brief and focusing mainly on developing potential therapeutic options that can be explored to manage this pandemic virus infection, which would help in valid countering of COVID-19.

Optimum uterine filling pressure for outpatient diagnostic hysteroscopy: a double-blind, randomized controlled trial.

This study designed a double-blind, randomized controlled trial to assess whether adequate visibility can be achieved with lower uterine filling pressures using normal saline for diagnostic outpatient hysteroscopy and whether patient discomfort can be reduced. A total of 234 patients were randomized to 40 mmHg (77 patients), 70 mmHg (78 patients) or 100 mmHg (79 patients) of uterine filling pressures. The primary outcome measure was the proportion of procedures where adequate visibility was achieved during diagnostic outpatient hysteroscopy. The secondary outcome was the level of pain experienced by the patient as assessed using a visual analogue scale. There was adequate visibility in 87.0% of cases in 40 mmHg group, 94.9% in 70 mmHg group and 97.5% in 100 mmHg group. Visibility was lower with 40 mmHg compared with 70 and 100 mmHg (P < 0.05). The mean pain score in each group was not significantly different. In conclusion, this study showed that there was a higher trend towards inadequate visibility with lower filling pressures. Pressures of 70 and 100 mmHg may be equivalent to each other but not to a pressure level of 40 mmHg. Pain scores do not differ significantly with the pressure options used.

QTL mapping of powdery mildew resistance in WI 2757 cucumber (Cucumis sativus L.).

Powdery mildew (PM) is a very important disease of cucumber (Cucumis sativus L.). Resistant cultivars have been deployed in production for a long time, but the genetic mechanisms of PM resistance in cucumber are not well understood. A 3-year QTL mapping study of PM resistance was conducted with 132 F2:3 families derived from two cucumber inbred lines WI 2757 (resistant) and True Lemon (susceptible). A genetic map covering 610.4 cM in seven linkage groups was developed with 240 SSR marker loci. Multiple QTL mapping analysis of molecular marker data and disease index of the hypocotyl, cotyledon and true leaf for responses to PM inoculation identified six genomic regions in four chromosomes harboring QTL for PM resistance in WI 2757. Among the six QTL, pm1.1 and pm1.2 in chromosome 1 conferred leaf resistance. Minor QTL pm3.1 (chromosome 3) and pm4.1 (chromosome 4) contributed to disease susceptibility. The two major QTL, pm5.1 and pm5.2 were located in an interval of ~40 cM in chromosome 5 with each explaining 21.0-74.5 % phenotypic variations. Data presented herein support two recessively inherited, linked major QTL in chromosome 5 plus minor QTL in other chromosomes that control the PM resistance in WI 2757. The QTL pm5.2 for hypocotyl resistance plays the most important role in host resistance. Multiple observations in the same year revealed the importance of scoring time in the detection of PM resistance QTL. Results of this study provided new insights into phenotypic and genetic mechanisms of powdery mildew resistance in cucumber.

Identification of SSR markers through bulk segregant analysis and inheritance of resistance to yellow vein mosaic disease in okra (Abelmoschus esculentus L. Moench).

Okra is an important traditional vegetable crop grown for its tender fruits in various tropical and sub tropical parts of the world. Yellow Vein Mosaic Disease (YVMD) is the major biotic factor causing severe threat to the okra fruit yield and qualities. The present study was conducted to find out the inheritance of resistance against YVMD and to identify the disease linked molecular markers through bulk segregant analysis. For this, the F1, BC1F1 and BC1F2 generations were derived from a cross between Abelmoschus manihot (PAUAcc-1) as resistant male parent and A. esculentus cv. Punjab Padmini as susceptible female parent. The whole set of populations (F1, BC1F1 and BC1F2) along with parents were subjected to artificial as well as filed screening against YVMD. Chi-square test for goodness to fit revealed that resistance against YVMD is controlled by two recessive genes. The allele of at least one gene in homozygous state mask the effect of other gene and produce a resistant phenotype. The very low polymorphism (31.5%) was detected between the parents by using SSR primers. Out of 200 SSR primers, the four primers i.e. Okra 032, Okra 049, Okra 129 and Okra 270 were found to be linked to YVMD through bulk segregant analysis. The identified SSR primers to YVMD could be further used in okra improvement for YVMD resistance. Supplementary Information: The online version contains supplementary material available at 10.1007/s13337-023-00844-9.

Variation of Mineral Composition in Different Fruit Parts of Bitter Gourd (Momordica charantia L.).

Bitter gourd (Momordica charantia L.), belonging to family Cucurbitaceae, is a good source of carbohydrates, proteins, vitamins, minerals, and bioactive compounds. In the present study, fruits (and its parts-epicarp, mesocarp, endocarp, seed, and whole fruit) of 56 accessions and 4 cultivars of Momordica spp. were assayed and compared for macro-minerals magnesium (Mg), potassium (K), sodium (Na), phosphorus (P), and calcium (Ca), and microminerals iron (Fe), zinc (Zn), manganese (Mn), and copper (Cu). Potassium was the most abundant macro-mineral found in whole fruit ranging from 78.40 to 483.49 mg/100 g dry weight (DW), followed by Mg (13.23-101.70 mg/100 g DW) in epicarp, P (32.22-98.24 mg/100 g DW) in endocarp, Ca (23.41-71.39 mg/100 g DW) in whole fruit, and Na (6.09-18.56 mg/100 g DW) in epicarp. The concentration of microminerals was recorded higher in seeds compared to other fruit parts. Levels of Fe were higher (0.76-6.14 mg/100 g DW), followed by Zn (0.87-2.64 mg/100 g DW), Cu (137.68-525.45 µg/100 g DW), and Mn (46.92-179.05 µg/100 g DW). The analysis depicted bitter gourd to be a potential source of both macro-minerals (K and Mg) and microminerals (Fe and Zn). The consumption of bitter gourd could be a health-promoting strategy to meet daily dietary intake requirements of essential minerals for human health.

Detection of porcine enteric picornaviruses from faecal samples of Indian pigs.

Porcine enteric picornaviruses often consequence diarrhoea and nervous complications in pig and pose enormous loss to pig farming. The present study expands the limited Indian data of porcine enteric picornaviruses which is needed for the early implementation of control measures and to check further outbreaks. A total of 398 porcine faecal samples from Uttar Pradesh, Madhya Pradesh, Chhattisgarh and Jharkhand state of India were screened for porcine teschovirus (PTV), porcine sapelovirus (PSV) and enterovirus G (EV-G) by reverse transcriptase-polymerase chain reaction (RT-PCR) using 5'UTR-specific primers. The prevalence of PTV, PSV and EV-G was found to be 12.81% (51/398), 5.77% (23/398) and 24.37% (97/398), respectively. EV-G was relatively higher in circulation in Indian pigs among all the included enteric picornaviruses. Conversely, the concurrent infection of more than one enteric picornavirus was also frequent. Supplementary Information: The online version contains supplementary material available at 10.1007/s13337-022-00756-0.

Fine genetic mapping of cp: a recessive gene for compact (dwarf) plant architecture in cucumber, Cucumis sativus L.

The compact (dwarf) plant architecture is an important trait in cucumber (Cucumis sativus L.) breeding that has the potential to be used in once-over mechanical harvest of cucumber production. Compact growth habit is controlled by a simply inherited recessive gene cp. With 150 F(2:3) families derived from two inbred cucumber lines, PI 308915 (compact vining) and PI 249561 (regular vining), we conducted genome-wide molecular mapping with microsatellite (simple sequence repeat, SSR) markers. A framework genetic map was constructed consisting of 187 SSR loci in seven linkage groups (chromosomes) covering 527.5 cM. Linkage analysis placed cp at the distal half of the long arm of cucumber Chromosome 4. Molecular markers cosegregating with the cp locus were identified through whole genome scaffold-based chromosome walking. Fine genetic mapping with 1,269 F(2) plants delimited the cp locus to a 220 kb genomic DNA region. Annotation and function prediction of genes in this region identified a homolog of the cytokinin oxidase (CKX) gene, which may be a potential candidate of compact gene. Alignment of the CKX gene homologs from both parental lines revealed a 3-bp deletion in the first exon of PI 308915, which can serve as a marker for marker-assisted selection of the compact phenotype. This work also provides a solid foundation for map-based cloning of the compact gene and understanding the molecular mechanisms of the dwarfing in cucumber.

High-Density GBS-Based Genetic Linkage Map Construction and QTL Identification Associated With Yellow Mosaic Disease Resistance in Bitter Gourd (Momordica charantia L.).

Yellow mosaic disease (YMD) in bitter gourd (Momordica charantia) is a devastating disease that seriously affects its yield. Although there is currently no effective method to control the disease, breeding of resistant varieties is the most effective and economic option. Moreover, quantitative trait locus (QTL) associated with resistance to YMD has not yet been reported. With the objective of mapping YMD resistance in bitter gourd, the susceptible parent "Punjab-14" and the resistant parent "PAUBG-6" were crossed to obtain F4 mapping population comprising 101 individuals. In the present study, the genotyping by sequencing (GBS) approach was used to develop the genetic linkage map. The map contained 3,144 single nucleotide polymorphism (SNP) markers, consisted of 15 linkage groups, and it spanned 2415.2 cM with an average marker distance of 0.7 cM. By adopting the artificial and field inoculation techniques, F4:5 individuals were phenotyped for disease resistance in Nethouse (2019), Rainy (2019), and Spring season (2020). The QTL analysis using the genetic map and phenotyping data identified three QTLs qYMD.pau_3.1, qYMD.pau_4.1, and qYMD.pau_5.1 on chromosome 3, 4, and 5 respectively. Among these, qYMD.pau_3.1, qYMD.pau_4.1 QTLs were identified during the rainy season, explaining the 13.5 and 21.6% phenotypic variance respectively, whereas, during the spring season, qYMD.pau_4.1 and qYMD.pau_5.1 QTLs were observed with 17.5 and 22.1% phenotypic variance respectively. Only one QTL qYMD.pau_5.1 was identified for disease resistance under nethouse conditions with 15.6% phenotypic variance. To our knowledge, this is the first report on the identification of QTLs associated with YMD resistance in bitter gourd using SNP markers. The information generated in this study is very useful in the future for fine-mapping and marker-assisted selection for disease resistance.

Quantitative Trait Loci Mapping for Earliness, Fruit, and Seed Related Traits Using High Density Genotyping-by-Sequencing-Based Genetic Map in Bitter Gourd (Momordica charantia L.).

Bitter gourd (Momordica charantia L.) is an important vegetable crop having numerous medicinal properties. Earliness and yield related traits are main aims of bitter gourd breeding program. High resolution quantitative trait loci (QTLs) mapping can help in understanding the molecular basis of phenotypic variation of these traits and thus facilitate marker-assisted breeding. The aim of present study was to identify genetic loci controlling earliness, fruit, and seed related traits. To achieve this, genotyping-by-sequencing (GBS) approach was used to genotype 101 individuals of F4 population derived from a cross between an elite cultivar Punjab-14 and PAUBG-6. This population was phenotyped under net-house conditions for three years 2018, 2019, and 2021. The linkage map consisting of 15 linkage groups comprising 3,144 single nucleotide polymorphism (SNP) markers was used to detect the QTLs for nine traits. A total of 50 QTLs for these traits were detected which were distributed on 11 chromosomes. The QTLs explained 5.09-29.82% of the phenotypic variance. The highest logarithm of the odds (LOD) score for a single QTL was 8.68 and the lowest was 2.50. For the earliness related traits, a total of 22 QTLs were detected. For the fruit related traits, a total of 16 QTLs and for seed related traits, a total of 12 QTLs were detected. Out of 50 QTLs, 20 QTLs were considered as frequent QTLs (FQ-QTLs). The information generated in this study is very useful in the future for fine-mapping and marker-assisted selection for these traits in bitter gourd improvement program.

Exploration of antigenic determinants in spike glycoprotein of SARS-CoV2 and identification of five salient potential epitopes.

Emerging pathogens have been an eternal threat to mankind. In a series of pandemics caused by notorious coronaviruses, a newly emerged SARS-CoV2 virus is creating panic among the world population. The unavailability of reliable theranostics insists the exploration of antigenic determinants in spike glycoprotein of SARS-CoV2. The four novel inserts ('70VSGTNGT76', '150KSWM153', 247SYLTPG252 and 674QTQTNSPRR682) in SARS-CoV2 spike protein were unraveled via multiple sequence alignment of spike proteins of SARS-CoV2, SARS-CoV, and MERS-CoV. The three-dimension (3D) modeling of the spike protein of the SARS-CoV2 and their interaction with the ACE2 receptor was delineated with the help of SWISS-MODEL and 3DLigandSite web servers. The predicted 3D model of SARS-CoV2 was further verified by SAVES, RAMPAGE, and ProSA-web tools. The potential B-cell immunogenic epitopes of SARS-CoV2 were predicted out by using various software viz. IEDB B-cell epitopes prediction tool, BepiPred linear epitope prediction tool, Emini Surface Accessibility Prediction tool, and Kolaskar-Tongaonkar antigenicity web tool. The five epitopes (i.e. '71SGTNGTKRFDN81, 247SYLTPG252, 634RVYST638, 675QTQTNSPRRARSV687, and 1054QSAPH1058) were selected as potent antigenic determinants. The quantum of information generated by this study will prove beneficial for the development of effective therapeutics, diagnostics, and multi-epitopic vaccines to combat this ongoing menace.

Advances in therapeutic and managemental approaches of bovine mastitis: a comprehensive review.

Mastitis (intramammary inflammation) caused by infectious pathogens is still considered a devastating condition of dairy animals affecting animal welfare as well as economically incurring huge losses to the dairy industry by means of decreased production performance and increased culling rates. Bovine mastitis is the inflammation of the mammary glands/udder of bovines, caused by bacterial pathogens, in most cases. Routine diagnosis is based on clinical and subclinical forms of the disease. This underlines the significance of early and rapid identification/detection of etiological agents at the farm level, for which several diagnostic techniques have been developed. Therapeutic regimens such as antibiotics, immunotherapy, bacteriocins, bacteriophages, antimicrobial peptides, probiotics, stem cell therapy, native secretory factors, nutritional, dry cow and lactation therapy, genetic selection, herbs, and nanoparticle technology-based therapy have been evaluated for their efficacy in the treatment of mastitis. Even though several strategies have been developed over the years for the purpose of managing both clinical and subclinical forms of mastitis, all of them lacked the efficacy to eliminate the associated etiological agent when used as a monotherapy. Further, research has to be directed towards the development of new therapeutic agents/techniques that can both replace conventional techniques and also solve the problem of emerging antibiotic resistance. The objective of the present review is to describe the etiological agents, pathogenesis, and diagnosis in brief along with an extensive discussion on the advances in the treatment and management of mastitis, which would help safeguard the health of dairy animals.

Bovine brucellosis - a comprehensive review.

Brucellosis is a zoonotic disease of great animal welfare and economic implications worldwide known since ancient times. The emergence of brucellosis in new areas as well as transmission of brucellosis from wild and domestic animals is of great significance in terms of new epidemiological dimensions. Brucellosis poses a major public health threat by the consumption of non-pasteurized milk and milk products produced by unhygienic dairy farms in endemic areas. Regular and meticulous surveillance is essentially required to determine the true picture of brucellosis especially in areas with continuous high prevalence. Additionally, international migration of humans, animals and trade of animal products has created a challenge for disease spread and diagnosis in non-endemic areas. Isolation and identification remain the gold standard test, which requires expertise. The advancement in diagnostic strategies coupled with screening of newly introduced animals is warranted to control the disease. Of note, the diagnostic value of miRNAs for appropriate detection of B. abortus infection has been shown. The most widely used vaccine strains to protect against Brucella infection and related abortions in cattle are strain 19 and RB51. Moreover, it is very important to note that no vaccine, which is highly protective, safe and effective is available either for bovines or human beings. Research results encourage the use of bacteriophage lysates in treatment of bovine brucellosis. One Health approach can aid in control of this disease, both in animals and man.

See-and-treat outpatient hysteroscopy: an analysis of 1109 examinations.

The aim of this study was to assess the feasibility of diagnostic and therapeutic outpatient hysteroscopy. Data were collected prospectively from 1109 consecutive hysteroscopy examinations. The main outcome measure was success and failure of diagnostic and therapeutic outpatient hysteroscopy examination. The mean age (sd) was 47.7 (11.8) years and 53.3% and 39.5% of subjects were post-menopausal and nulliparous, respectively. The most common indications for referral were post-menopausal bleeding (39.8%), menorrhagia (25.7%) and irregular periods (14.5%). Hysteroscopy examination was successfully completed in 96.2% (1067/1109) of the subjects. Success was negatively influenced by age and menopausal status but not parity, although the differences between the age groups and pre- versus post-menopausal groups were minimal. The most common abnormalities were intrauterine polyps (425/1109, 38.3%) and submucous fibroids (142/1109, 12.8%). Of these two groups, respectively, 285/425 (67.1%) and 23/142 (16.2%) subjects had complete polyp and fibroid resection in the outpatient setting and 116/425 (27.3%) and 63/142 (44.4%) underwent polyp and fibroid resection under general anaesthesia. In conclusion, diagnostic and therapeutic hysteroscopy is feasible and highly successful in an outpatient setting. The majority of subjects with endometrial polyps and intrauterine adhesions are amenable to a see-and-treat approach.

Possibility of SARS-CoV-2 transmission from the breast milk of COVID-19 affected women patients to their infants: worries and strategies to counter it.

Not available.

An update on SARS-CoV-2/COVID-19 with particular reference to its clinical pathology, pathogenesis, immunopathology and mitigation strategies.

Coronavirus Disease 2019 (COVID-19), emerged in early December 2019 in China and became a pandemic situation worldwide by its rapid spread to more than 200 countries or territories. Bats are considered as the reservoir host, and the search of a probable intermediate host is still going on. The severe form of the infection is associated with death is mainly reported in older and immune-compromised patients with pre-existing disease history. Death in severe cases is attributed to respiratory failure associated with hyperinflammation. Cytokine storm syndrome associated with inflammation in response to SARS-CoV-2 infection is considered as the leading cause of mortality in COVID-19 patients. COVID-19 patients have thus higher levels of many proinflammatory cytokines and chemokines. The blood laboratory profile of the COVID-19 patients exhibits lymphopenia, leukopenia, thrombocytopenia, and RNAaemia, along with increased levels of aspartate aminotransferase. SARS-CoV-2 infection in pregnant women does not lead to fetus mortality, unlike other zoonotic coronaviruses such as SARS-CoV and MERS-CoV, and there is, to date, no evidence of intrauterine transmission to neonates. Rapid diagnostics have been developed, and significant efforts are being made to develop effective vaccines and therapeutics. In the absence of any virus-specific therapy, internationally, health care authorities are recommending the adoption of effective community mitigation measures to counter and contain this pandemic virus. This paper is an overview of this virus and the disease with a particular focus on SARS-CoV-2/COVID-19 clinical pathology, pathogenesis, and immunopathology, along with recent research developments.

Pathodynamics of Circulating Strains of Duck Enteritis Virus: A Step Forward to Understand Its Pathogenesis.

Duck enteritis virus (DEV) causes an acute and contagious infection in duck. The present study was carried out to evaluate the pathogenicity and pathodynamics of DEV isolates from different natural outbreaks in the Assam Province of India. A total of six wild-type isolates of DEV were revived in ducklings to determine its biologic characterization. Postmortem examination of infected ducklings revealed DEV-specific gross lesions in different organs. The presence of DEV was confirmed by its genome amplification and the presence of viral antigens from collected tissue samples by indirect fluorescent antibody test. All the isolates revived in ducklings were further propagated in duck embryo fibroblast cells. Highly virulent and low virulent isolates of DEV were selected for further study based on median duck infectivity dose (DID50) and median tissue culture infectivity dose (TCID50). The highly virulent isolate of DEV had values of 102 DID50/ml and 106.33 TCID50/ml, whereas the low virulent strain had titers of 10 DID50/ml and 104.83 TCID50/ml in the cell culture. Our results showed replication of DEV in ducks with the highest and lowest viral titers in the thymus and bursa of Fabricius, respectively. In addition, microscopic analysis revealed necrosis and degeneration of submucosal esophageal glands and glandular epithelium. The study will be useful to understand the organ tropism and pathologic alteration among the virulent DEV isolates.

Patodinámica de las cepas circulantes del virus de la enteritis del pato: Un paso adelante para comprender su patogenia. El virus de la enteritis del pato (DEV) causa una infección aguda y contagiosa en el pato. El presente estudio se llevó a cabo para evaluar la patogenicidad y la patodinámica de los aislamientos del virus de la enteritis del pato de diferentes brotes naturales en la provincia de Assam en la India. Se replicaron un total de seis aislamientos del virus de la enteritis del pato de tipo silvestre en patitos para su caracterización biológica. El examen post mortem de los patitos infectados reveló lesiones macroscópicas específicas de la enteritis viral en diferentes órganos. La presencia del virus de la enteritis viral de pato fue confirmada por su amplificación del genoma y por la presencia de antígenos virales mediante la prueba indirecta de anticuerpos fluorescentes con muestras de tejido recolectadas. Todos los aislamientos replicados en patitos se propagaron adicionalmente en células de fibroblastos de embriones de pato. Se seleccionaron aislamientos del virus de la enteritis del pato altamente virulentos y poco virulentos para un estudio adicional basado en la dosis de infectividad en el pato (DID50) y la dosis de infectividad de cultivo de tejidos (TCID50). El aislado altamente virulento del virus de la enteritis del pato mostró valores de 102 DID50/ml y 106.33 TCID50/ml, mientras que la cepa virulenta baja tenía títulos de 10 DID50/ml y 104.83 TCID50/ml en cultivo celular. Nuestros resultados mostraron la replicación del virus de la enteritis viral en patos con los títulos virales más altos y más bajos en el timo y en la bolsa de Fabricio, respectivamente. Además, el análisis microscópico reveló necrosis y degeneración de las glándulas esofágicas submucosas y del epitelio glandular. El estudio será útil para comprender el tropismo de los órganos y la alteración patológica entre los aislados virulentos del virus de la enteritis viral del pato.