Pathology, virulence-associated gene profiling, antimicrobial susceptibility, and pathogenicity of untypeable capsular serotypes of Pasteurella multocida isolated from slaughtered pigs of India.

Pasteurella multocida is widely distributed in all pig-rearing countries, affecting the economic viability and profitability of pig production. The present research highlights the molecular characterization and pathology of untypeable capsular serotypes of P. multocida in slaughtered pigs from prominent pig-rearing states of India. The prevalence of Pasteurellosis was 27.17% by Pasteurella multocida specific Pasteurella multocida specific PCR (PM-PCR). assay, while isolation rate was 7.62%. The microscopic lesions of bronchopneumonia, tonsillitis, and the presence of bacterial antigens in immunohistochemistry confirmed P. multocida with pathologies. In capsular typing, the majority of the isolates were untypeable with prevalence of 52.15% and 43.58% in molecular and microbiological methods, respectively. All the isolates showed the uniform distribution of virulence genes such as exbB, nanB, sodC, plpB, and oma87 (100%), while the variations were observed in ptfA, hasR, ptfA, pfhA, hsf-1, and plpE genes. The untypeable isolates showed higher prevalence of hsf-1 gene as compared to others. The untypeable serotypes showed a higher degree of resistance to ampicillin, amoxicillin, and penicillin antibiotics. The mouse pathogenicity testing of untypeable capsular isolates confirmed its pathogenic potential. The higher frequency of pathogenic untypeable isolates with antibiotic resistance profile might pose a serious threat to the pigs, and therefore, preventive measures should be adopted for effective control.

Molecular detection and patho-morphological study of enteric Escherichia coli pathotypes in diarrheic neonatal calves.

To understand the pathology of natural cases of E. coli pathotypes infection in bovine calves, 45 cases of bovine calves, below one month of age, died due to enteritis were studied. Total seventeen cases (37.77%) turned positive for different pathotypes of E. coli by RT-PCR. Out of seventeen positive samples for E. coli, six cases (35.29%) were positive for eae gene, three cases (17.64%) for bfp gene and eight cases (47.05) for fimA gene of E. coli. Gross lesions in these cases showed pin-point to ecchymotic hemorrhages in the mucosa of jejunum, ileum and colon. The draining mesenteric lymph nodes were swollen, enlarged and showed cord -like structure. Histopathology of small intestine showed, villi lining cells were sloughed off, tips of villi capillary plexus were congested and hemorrhagic, and skipping lesions of microabscesses in the crypts of mucosa were observed. In the duodenum, necrosis of crypts and infiltration of mononuclear cells in the lamina propria and around Brunner's gland. In mesenteric lymph nodes the subscapular space were infiltrated with mononuclear cells with depletion of lymphoid follicles in cortical area. Peri-trabecular and medullary sinuses of mesenteric lymph nodes were necrosed.

A comprehensive review on pharmacologic agents, immunotherapies and supportive therapeutics for COVID-19.

The emergence of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has affected many countries throughout the world. As urgency is a necessity, most efforts have focused on identifying small molecule drugs that can be repurposed for use as anti-SARS-CoV-2 agents. Although several drug candidates have been identified using in silico method and in vitro studies, most of these drugs require the support of in vivo data before they can be considered for clinical trials. Several drugs are considered promising therapeutic agents for COVID-19. In addition to the direct-acting antiviral drugs, supportive therapies including traditional Chinese medicine, immunotherapies, immunomodulators, and nutritional therapy could contribute a major role in treating COVID-19 patients. Some of these drugs have already been included in the treatment guidelines, recommendations, and standard operating procedures. In this article, we comprehensively review the approved and potential therapeutic drugs, immune cells-based therapies, immunomodulatory agents/drugs, herbs and plant metabolites, nutritional and dietary for COVID-19.

Virus distribution and early pathogenesis of highly pathogenic peste-des-petits-ruminants virus in experimentally infected goats.

INTRODUCTION: Despite causing one of the most dreaded diseases of small ruminants, relatively little is known about the pathogenic events, antigen distribution and the cells responsible for the uptake and transmission of peste-des-petits-ruminants virus (PPRV) during primitive stages of infection. OBJECTIVES: We aimed at deciphering the sequential tissue tropism, pathological events and putative role of M2c macrophages during incubatory, prodromal and invasive stages of PPRV infection. METHODOLOGY: A total of 10 goats were sequentially sacrificed at 1, 2, 3, 4, and 5 days post-infection (dpi, n = 2 per time-point) following intranasal inoculation with a highly virulent strain of PPRV (lineage IV PPRV/Izatnagar/94). Histological evaluation to assess PPRV mediated pathologies, RT-qPCR and immunohistochemistry (IHC) to decipher sequential virus distribution, and dual immunolabelling to determine the role of M2c macrophage in early PPRV uptake and transmission was performed. RESULTS: PPRV/Izatnagar/94 caused major pathologies in the lung tissues. Unprecedentedly, PPRV nucleic acid and antigens were detected in various tissues as early as one dpi. RT-qPCR revealed PPRV in the nasal cavity, trachea, bronchi, tongue and lymph nodes draining these tissues from 1 dpi. IHC affirms cells residing in the lamina propria and submucosa of the respiratory tract and tongue and peribronchiolar areas of lungs as the primary target of PPRV. Following initial replication in the respiratory tract, PPRV is transmitted to the regional lymph nodes where primary viral amplification occurs. After viraemia and secondary replication in generalized lymphoid tissues, PPRV infects and replicates in the epithelial cells. Further, we localized CD163+ M2c macrophages in the goat tissues, but dual IHC elucidated that M2c macrophages do not facilitate uptake and transmission of PPRV during the early stages of infection. CONCLUSION: Our study substantiates the disease establishment process and pathogenesis of PPRV/Izatnagar/94 during the incubatory and prodromal stages of infection. Further, we have also observed M2c macrophage distribution in the goat tissues and demonstrated that they do not pick and transmit PPRV.

Contrasting selective patterns across the segmented genome of bluetongue virus in a global reassortment hotspot.

For segmented viruses, rapid genomic and phenotypic changes can occur through the process of reassortment, whereby co-infecting strains exchange entire segments creating novel progeny virus genotypes. However, for many viruses with segmented genomes, this process and its effect on transmission dynamics remain poorly understood. Here, we assessed the consequences of reassortment for selection on viral diversity through time using bluetongue virus (BTV), a segmented arbovirus that is the causative agent of a major disease of ruminants. We analysed ninety-two BTV genomes isolated across four decades from India, where BTV diversity, and thus opportunities for reassortment, are among the highest in the world. Our results point to frequent reassortment and segment turnover, some of which appear to be driven by selective sweeps and serial hitchhiking. Particularly, we found evidence for a recent selective sweep affecting segment 5 and its encoded NS1 protein that has allowed a single variant to essentially invade the full range of BTV genomic backgrounds and serotypes currently circulating in India. In contrast, diversifying selection was found to play an important role in maintaining genetic diversity in genes encoding outer surface proteins involved in virus interactions (VP2 and VP5, encoded by segments 2 and 6, respectively). Our results support the role of reassortment in driving rapid phenotypic change in segmented viruses and generate testable hypotheses for in vitro experiments aiming at understanding the specific mechanisms underlying differences in fitness and selection across viral genomes.

Evidence of subclinical foot-and-mouth disease virus infection in young calves born from clinically recovered cow under natural condition.

Foot-and-mouth disease (FMD) is a highly contagious and economically important, transboundary viral disease of cloven-hoofed animals. It is known that an asymptomatic, persistent FMD virus (FMDV) infection may occur subsequent to acute or subclinical FMDV infection in adult ruminants. However, virus persistence in young calves has not been studied. In the current investigation, FMDV infection parameters were examined for calves born to FMD-clinically recovered cows (CRC), asymptomatic cows from infected herds (ASC) and cows from with no history of FMD (NHF). The study was conducted in natural condition after FMD outbreaks in two dairy herds in India. No calves described herein had any clinical signs of FMD. Six out of 12 calves born to CRC had detectable FMDV RNA in oesophageal-pharyngeal fluid consistent with asymptomatic FMDV infection. Three of the 12 calves of CRC group had seroreactivity against FMDV non-structural proteins. One calf had detectable FMDV RNA at two consecutive samplings at 2 months apart. However, infectious FMDV was not isolated from any calf in the study. None of the calves in the ASC or NHF groups had any evidence of FMDV infection. Overall, these data are consistent with earlier report on calves having been infected in utero. Further investigation of FMDV persistence in calves under controlled conditions may lead to greater understanding of the viral pathogenesis.

Oxidative impairment and histopathological alterations in kidney and brain of mice following subacute lambda-cyhalothrin exposure.

Lambda cyhalothrin (LCT), a broad-spectrum type II (α-cyano) synthetic pyrethroid pesticide, is widely employed in various agricultural and animal husbandry practices for the control of pests. Acute and chronic exposure to LCT can elicit several adverse effects including oxidative stress. With the objective to investigate nephrotoxicity and neurotoxicity of LCT in mice, we evaluated oxidative stress parameters and histological changes in the kidney and brain of LCT exposed mice. Swiss albino mice were divided randomly into four groups ( n = 6 per group) as: (A) corn oil/vehicle control; (B) 0.5 mg/kg body weight (b.w.) LCT; (C) 1 mg/kg b.w. LCT; (D) 2 mg/kg b.w. LCT. Mice were treated orally for 28 days. LCT exposure significantly increased serum urea nitrogen, creatinine and urea levels. LCT exposure also increased lipid peroxidation, superoxide anion generation, nitrite level and decreased the level of reduced glutathione. The activities of superoxide dismutase, catalase and glutathione- S-transferase were depleted significantly in both kidney and brain. Histological examination revealed marked histopathological changes in the kidney and brain of mice that were more pronounced at high dose of LCT. Thus, results of the present study indicate that 28 days oral exposure of LCT causes oxidative damage to the kidney and brain of mice which in turn could be responsible for nephrotoxicity and neurotoxicity. Nevertheless, further detailed studies are required to prove these effects especially after long-term exposure.

Sequence analysis of bluetongue virus serotype 8 from the Netherlands 2006 and comparison to other European strains.

During 2006 the first outbreak of bluetongue ever recorded in northern Europe started in Belgium and the Netherlands, spreading to Luxemburg, Germany and north-east France. The virus overwintered (2006-2007) reappearing during May-June 2007 with greatly increased severity in affected areas, spreading further into Germany and France, reaching Denmark, Switzerland, the Czech Republic and the UK. Infected animals were also imported into Poland, Italy, Spain and the UK. An initial isolate from the Netherlands (NET2006/04) was identified as BTV-8 by RT-PCR assays targeting genome segment 2. The full genome of NET2006/04 was sequenced and compared to selected European isolates, South African vaccine strains and other BTV-8 strains, indicating that it originated in sub-Saharan Africa. Although NET2006/04 showed high levels of nucleotide identity with other 'western' BTV strains, it represents a new introduction and was not derived from the BTV-8 vaccine, although its route of entry into Europe has not been established.