scholarly journals Experimental induction of necrotic enteritis with or without predisposing factors using netB positive Clostridium perfringens strains

Gut Pathogens ◽  
2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Mudassar Mohiuddin ◽  
Weikang Yuan ◽  
Zhongfeng Song ◽  
Shenquan Liao ◽  
Nanshan Qi ◽  
...  
Keyword(s):  
Fish Meal ◽  
Severe Disease ◽  
Clinical Signs ◽  
High Protein Diet ◽  
Predisposing Factors ◽  
Necrotic Enteritis ◽  
Lesion Score ◽  
Poultry Birds ◽  
Specific Pathogen

Abstract Background Poultry necrotic enteritis (NE) is an economically important disease caused by C. perfringens. The disease causing ability of this bacterium is linked with the production of a wide variety of toxins. Among them, necrotic enteritis B-like (NetB) toxin is reported to be involved in the pathogenesis of NE; in addition there is some circumstantial evidence that tpeL toxin may enhance virulence, but this is yet to be definitely shown. The situation becomes more complicated in the presence of a number of predisposing factors like co-infection with coccidia, type of diet and use of high protein diet. These co-factors alter the intestinal environment, thereby favoring the production of more toxins, leading to a more severe disease. The objective of this study was to develop a successful animal model that would induce clinical signs and lesions of NE using C. perfringens type G strains obtained from field outbreaks. A separate trial was simultaneously considered to establish the role of dietary factor with coccidial co-infection in NE. Results The results have shown that use of net-B positive C. perfringens without predisposing factors induce moderate to severe NE (Av. Lesion score 1.79 ± 1.50). In a separate trial, addition of fish meal to a feed of C. perfringens challenged birds produced higher number of NE cases (Av. Lesion score 2.17 ± 1.28). However, use of less virulent E. necatrix strain along with fish meal in conjunction with net-B positive strain did not alter the severity of NE lesions in specific pathogen free chicken (Av. Lesion score 2.21 ± 1.13). Conclusions This study suggests that virulent C. perfringens type G strains can induce NE lesions in the absence of other predisposing factors. Birds in the clostridia challenged group showed moderate to severe NE lesions. Use of less virulent coccidia strain contributed to a lesser extent in increasing the severity of disease. Maize based diet along with fishmeal (1:1) increased the severity of lesions but statistically it was non-significant. The NE lesions in all experimental groups were found to be present more frequently in the duodenum. In this way, this study provided an effective model for in vivo production of NE in poultry birds.

Effect of protein rich diet on experimental pathology of necrotic enteritis in broilers

2014 ◽  
Vol 11 (1) ◽  
pp. 21-29 ◽  
Author(s):  
MJ Ferdoush ◽  
MM Rashid ◽  
M Dipti ◽  
P Roy ◽  
PM Das ◽  
...  
Keyword(s):  
Fish Meal ◽  
Anaerobic Bacteria ◽  
Clinical Signs ◽  
Intestinal Content ◽  
Necrotic Enteritis ◽  
Predisposing Factor ◽  
Experimental Pathology ◽  
Group A ◽  
Group B ◽  
Protein Rich

This study was designed to know the effect of protein rich diet (50% fish meal) on the experimental pathology of necrotic enteritis in broilers. The Clostridium (Cl.) perfringens was obtained from the Department of Pathology, Bangladesh Agricultural University. Reconfirmation and recharacterization of Cl. perfringens were performed by culture, microscopic examination, staining and biochemical tests. The experimental pathologic studies were performed with supplementation of protein rich diet and challenged with Cl. perfringens in broilers. The dose of the inoculum for experimental infection with Cl. perfringens was 1x108 CFU/2.5ml. Fifteen birds of 21 days old were divided into 3 (A, B and C) groups each containing 5 birds. Birds of group A were fed with 50% fish meal at a rate of 500gm /kg of feed from day 21 to day 34 and challenged from day 28 to day 32 with 1x108 CFU/2.5ml. Birds of group B were fed with normal feed and challenged on day 28 for consecutive five days. Group C was kept as control with commercial normal pellet without Cl. perfringens. Birds of all groups were observed up to 34 days of age for clinical signs. Eighty percent (4/5) of the birds of group A developed moderate clinical signs like diarrhoea, ruffled feather and less feed intake whereas 40% (2/5) birds of group B developed same clinical signs like group A but in mild form. There was no mortality in any groups. All the birds were sacrificed at Day 35. Severe necrosis and hemorrhage in intestine, enlarged liver and hemorrhage in the base of heart were noted in the birds of group A. On an average 2-5 bacteria were found in impression smear of intestines in higher magnification (100x), and anaerobic bacteria counted from intestinal content was 1.51x107CFU/ml. In histopathology, necrosis and reactive cells were found in liver, heart, lung and sloughing off intestinal epithelium was also found in intestines. On the other hand similar lesions like group A were observed in the birds of group B but in moderate form and no bacteria was found in impression smears of intestines. Anaerobic bacteria counted from intestinal content of this group was 1.1x107CFU/ml. In histopathology necrosis, reactive cells were found but less than group A. The birds of group C were normal in all parameters. However, anaerobic bacteria count from the intestinal content was 0.8x107CFU/ml. From this study, it may be concluded that protein rich diet is a predisposing factor for necrotic enteritis in broilers. DOI: http://dx.doi.org/10.3329/bjvm.v11i1.17729 Bangl. J. Vet. Med. (2013). 11 (1): 21-29

scholarly journals Efficacy of Mitochondrial Antioxidant Plastoquinonyl-decyl-triphenylphosphonium Bromide (SkQ1) in the Rat Model of Autoimmune Arthritis

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Alexander A. Andreev-Andrievskiy ◽  
Nataliya G. Kolosova ◽  
Natalia A. Stefanova ◽  
Maxim V. Lovat ◽  
Maxim V. Egorov ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Wistar Rats ◽  
Clinical Signs ◽  
Therapeutic Window ◽  
Autoimmune Arthritis ◽  
Dependent Manner ◽  
Specific Pathogen ◽  
Triphenylphosphonium Bromide

Rheumatoid arthritis is one of the most common autoimmune diseases. Many antioxidants have been tested in arthritis, but their efficacy was, at best, marginal. In this study, a novel mitochondria-targeted antioxidant, plastoquinonyl-decyl-triphenylphosphonium bromide (SkQ1), was testedin vivoto prevent and cure experimental autoimmune arthritis. In conventional Wistar rats, SkQ1 completely prevented the development of clinical signs of arthritis if administered with food before induction. Further, SkQ1 significantly reduced the fraction of animals that developed clinical signs of arthritis and severity of pathological lesions if administration began immediately after induction of arthritis or at the onset of first symptoms (day 14 after induction). In specific pathogen-free Wistar rats, SkQ1 administered via gavage after induction of arthritis did not reduce the fraction of animals with arthritis but decreased the severity of lesions upon pathology examination in a dose-dependent manner. Efficacious doses of SkQ1 were in the range of 0.25–1.25 nmol/kg/day (0.13–0.7 μg/kg/day), which is much lower than doses commonly used for conventional antioxidants. SkQ1 promoted apoptosis of neutrophilsin vitro, which may be one of the mechanisms underlying its pharmacological activity. Considering its low toxicity and the wide therapeutic window, SkQ1 may be a valuable additional therapy for rheumatoid arthritis.

scholarly journals AttenuatedSalmonella typhimuriumSV4089 as a Potential Carrier of Oral DNA Vaccine in Chickens

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Seyed Davoud Jazayeri ◽  
Aini Ideris ◽  
Zunita Zakaria ◽  
Abdul Rahman Omar
Keyword(s):  
Dna Vaccine ◽  
Oral Vaccine ◽  
Serum Antibody ◽  
Clinical Signs ◽  
Eukaryotic Expression ◽  
Specific Pathogen ◽  
Viable Bacteria

AttenuatedSalmonellahas been used as a carrier for DNA vaccine. However,in vitroandin vivostudies on the bacteria following transfection of plasmid DNA were poorly studied. In this paper, eukaryotic expression plasmids encoding avian influenza virus (AIV) subtype H5N1 genes, pcDNA3.1/HA, NA, and NP, were transfected into an attenuatedSalmonella enteric typhimuriumSV4089.In vitrostability of the transfected plasmids intoSalmonellawere over 90% after 100 generations. The attenuatedSalmonellawere able to invade MCF-7 (1.2%) and MCF-10A (0.5%) human breast cancer cells. Newly hatched specific-pathogen-free (SPF) chicks were inoculated once by oral gavage with 109colony-forming unit (CFU) of the attenuatedSalmonella. No abnormal clinical signs or deaths were recorded after inoculation. Viable bacteria were detected 3 days after inoculation by plating from spleen, liver, and cecum. Fluorescentin situhybridization (FISH) and polymerase chain reaction (PCR) were carried out for confirmation.Salmonellawas not detected in blood cultures although serum antibody immune responses toSalmonellaO antiserum group D1 factor 1, 9, and 12 antigens were observed in all the inoculated chickens after 7 days up to 35 days. Our results showed that live attenuatedS. typhimuriumSV4089 harboring pcDNA3.1/HA, NA, and NP may provide a unique alternative as a carrier for DNA oral vaccine in chickens.

scholarly journals SARS-CoV-2 B.1.1.7 infection of Syrian hamster does not cause more severe disease and is protected by naturally acquired immunity

2021 ◽  
Author(s):  
Ivette A Nunez ◽  
Christopher Z Lien ◽  
Prabhuanand Selvaraj ◽  
Charles B Stauft ◽  
Shufeng Liu ◽  
...  
Keyword(s):  
Immune Escape ◽  
Natural Infection ◽  
Severe Disease ◽  
Clinical Signs ◽  
Epidemiological Studies ◽  
Viral Fitness ◽  
Lung Pathology ◽  
Viral Loads ◽  
Induced Immunity

Epidemiological studies have revealed the emergence of multiple SARS-CoV-2 variants of concern (VOC), including the lineage B.1.1.7 that is rapidly replacing old variants. The B.1.1.7 variant has been linked to increased morbidity rates, transmissibility, and potentially mortality. To assess viral fitness in vivo and to address whether the B.1.1.7 variant is capable of immune escape, we conducted infection and re-infection studies in naive and convalescent Syrian hamsters (>10 months old). Hamsters infected by either a B.1.1.7 variant or a B.1 (G614) variant exhibited comparable viral loads and pathology. Convalescent hamsters that were previously infected by the original D614 variant were protected from disease following B.1.1.7 challenge with no observable clinical signs or lung pathology. Altogether, our study did not find that the B.1.1.7 variant significantly differs from the B.1 variant in pathogenicity in hamsters and that natural infection-induced immunity confers protection against a secondary challenge by the B1.1.7 variant.

scholarly journals Single-cell RNA sequencing reveals ex vivo signatures of SARS-CoV-2-reactive T cells through ‘reverse phenotyping’

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
David S. Fischer ◽  
Meshal Ansari ◽  
Karolin I. Wagner ◽  
Sebastian Jarosch ◽  
Yiqi Huang ◽  
...  
Keyword(s):  
T Cells ◽  
Single Cell ◽  
Rna Sequencing ◽  
Ex Vivo ◽  
Severe Disease ◽  
Human Leukocyte ◽  
Cell Receptor ◽  
Single Cell Rna Sequencing

AbstractThe in vivo phenotypic profile of T cells reactive to severe acute respiratory syndrome (SARS)-CoV-2 antigens remains poorly understood. Conventional methods to detect antigen-reactive T cells require in vitro antigenic re-stimulation or highly individualized peptide-human leukocyte antigen (pHLA) multimers. Here, we use single-cell RNA sequencing to identify and profile SARS-CoV-2-reactive T cells from Coronavirus Disease 2019 (COVID-19) patients. To do so, we induce transcriptional shifts by antigenic stimulation in vitro and take advantage of natural T cell receptor (TCR) sequences of clonally expanded T cells as barcodes for ‘reverse phenotyping’. This allows identification of SARS-CoV-2-reactive TCRs and reveals phenotypic effects introduced by antigen-specific stimulation. We characterize transcriptional signatures of currently and previously activated SARS-CoV-2-reactive T cells, and show correspondence with phenotypes of T cells from the respiratory tract of patients with severe disease in the presence or absence of virus in independent cohorts. Reverse phenotyping is a powerful tool to provide an integrated insight into cellular states of SARS-CoV-2-reactive T cells across tissues and activation states.

scholarly journals Experimental infection of indigenous North African goats with goatpox virus

2021 ◽  
Vol 63 (1) ◽  
Author(s):  
Jihane Hamdi ◽  
Zahra Bamouh ◽  
Mohammed Jazouli ◽  
Meryem Alhyane ◽  
Najet Safini ◽  
...  
Keyword(s):  
Antibody Response ◽  
Experimental Infection ◽  
Subcutaneous Tissue ◽  
Severe Disease ◽  
Clinical Signs ◽  
Economic Losses ◽  
North African ◽  
Cutaneous Lesions ◽  
Viral Dna ◽  
Goatpox Virus

Abstract Background Goatpox is a viral disease caused by infection with goatpox virus (GTPV) of the genus Capripoxvirus, Poxviridae family. Capripoxviruses cause serious disease to livestock and contribute to huge economic losses. Goatpox and sheeppox are endemic to Africa, particularly north of the Equator, the Middle East and many parts of Asia. GTPV and sheeppox virus are considered host-specific; however, both strains can cause clinical disease in either goats or sheep with more severe disease in the homologous species and mild or sub-clinical infection in the other. Goatpox has never been reported in Morocco, Algeria or Tunisia despite the huge population of goats living in proximity with sheep in those countries. To evaluate the susceptibility and pathogenicity of indigenous North African goats to GTPV infection, we experimentally inoculated eight locally bred goats with a virulent Vietnamese isolate of GTPV. Two uninfected goats were kept as controls. Clinical examination was carried out daily and blood was sampled for virology and for investigating the antibody response. After necropsy, tissues were collected and assessed for viral DNA using real-time PCR. Results Following the experimental infection, all inoculated goats displayed clinical signs characteristic of goatpox including varying degrees of hyperthermia, loss of appetite, inactivity and cutaneous lesions. The infection severely affected three of the infected animals while moderate to mild disease was noticed in the remaining goats. A high antibody response was developed. High viral DNA loads were detected in skin crusts and nodules, and subcutaneous tissue at the injection site with cycle threshold (Ct) values ranging from 14.6 to 22.9, while lower viral loads were found in liver and lung (Ct = 35.7 and 35.1). The results confirmed subcutaneous tropism of the virus. Conclusion Clinical signs of goatpox were reproduced in indigenous North African goats and confirmed a high susceptibility of the North African goat breed to GTPV infection. A clinical scoring system is proposed that can be applied in GTPV vaccine efficacy studies.

scholarly journals Measurement of the Intestinal pH in Mice under Various Conditions Reveals Alkalization Induced by Antibiotics

Antibiotics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 180
Author(s):  
Kouki Shimizu ◽  
Issei Seiki ◽  
Yoshiyuki Goto ◽  
Takeshi Murata
Keyword(s):  
Antibiotic Treatment ◽  
High Protein Diet ◽  
Intestinal Bacteria ◽  
High Protein ◽  
Protein Diet ◽  
Germ Free ◽  
Treatment Regimens ◽  
Ph Values ◽  
Specific Pathogen ◽  
The Stability

The intestinal pH can greatly influence the stability and absorption of oral drugs. Therefore, knowledge of intestinal pH is necessary to understand the conditions for drug delivery. This has previously been measured in humans and rats. However, information on intestinal pH in mice is insufficient despite these animals being used often in preclinical testing. In this study, 72 female ICR mice housed in SPF (specific pathogen-free) conditions were separated into nine groups to determine the intestinal pH under conditions that might cause pH fluctuations, including high-protein diet, ageing, proton pump inhibitor (PPI) treatment, several antibiotic treatment regimens and germ-free mice. pH was measured in samples collected from the ileum, cecum and colon, and compared to control animals. An electrode, 3 mm in diameter, enabled accurate pH measurements with a small amount of gastrointestinal content. Consequently, the pH values in the cecum and colon were increased by high-protein diet, and the pH in the ileum was decreased by PPI. Drastic alkalization was induced by antibiotics, especially in the cecum and colon. The alkalized pH values in germ-free mice suggested that the reduction in the intestinal bacteria caused by antibiotics led to alkalization. Alkalization of the intestinal pH caused by antibiotic treatment was verified in mice. We need further investigations in clinical settings to check whether the same phenomena occur in patients.

scholarly journals SARS-CoV-2-Laden Respiratory Aerosol Deposition in the Lung Alveolar-Interstitial Region Is a Potential Risk Factor for Severe Disease: A Modeling Study

2021 ◽  
Vol 11 (5) ◽  
pp. 431
Author(s):  
Sabine Hofer ◽  
Norbert Hofstätter ◽  
Albert Duschl ◽  
Martin Himly
Keyword(s):  
Risk Factor ◽  
Particle Deposition ◽  
Early Stage ◽  
Severe Disease ◽  
Ambient Air ◽  
Aerosol Deposition ◽  
Pulmonary Involvement ◽  
Mild Disease ◽  
Disease Initiation

COVID-19, predominantly a mild disease, is associated with more severe clinical manifestation upon pulmonary involvement. Virion-laden aerosols and droplets target different anatomical sites for deposition. Compared to droplets, aerosols more readily advance into the peripheral lung. We performed in silico modeling to confirm the secondary pulmonary lobules as the primary site of disease initiation. By taking different anatomical aerosol origins into consideration and reflecting aerosols from exhalation maneuvers breathing and vocalization, the physicochemical properties of generated respiratory aerosol particles were defined upon conversion to droplet nuclei by evaporation at ambient air. To provide detailed, spatially-resolved information on particle deposition in the thoracic region of the lung, a top-down refinement approach was employed. Our study presents evidence for hot spots of aerosol deposition in lung generations beyond the terminal bronchiole, with a maximum in the secondary pulmonary lobules and a high preference to the lower lobes of both lungs. In vivo, initial chest CT anomalies, the ground glass opacities, resulting from partial alveolar filling and interstitial thickening in the secondary pulmonary lobules, are likewise localized in these lung generations, with the highest frequency in both lower lobes and in the early stage of disease. Hence, our results suggest a disease initiation right there upon inhalation of virion-laden respiratory aerosols, linking the aerosol transmission route to pathogenesis associated with higher disease burden and identifying aerosol transmission as a new independent risk factor for developing a pulmonary phase with a severe outcome.

scholarly journals Transcriptomic Analysis of Inbred Chicken Lines Reveals Infectious Bursal Disease Severity Is Associated with Greater Bursal Inflammation In Vivo and More Rapid Induction of Pro-Inflammatory Responses in Primary Bursal Cells Stimulated Ex Vivo

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 933
Author(s):  
Amin S. Asfor ◽  
Salik Nazki ◽  
Vishwanatha R.A.P. Reddy ◽  
Elle Campbell ◽  
Katherine L. Dulwich ◽  
...  
Keyword(s):  
Rho Gtpases ◽  
Inflammatory Responses ◽  
Ex Vivo ◽  
Severe Disease ◽  
Infectious Bursal Disease ◽  
Rna Seq ◽  
Rapid Induction ◽  
Cytoskeletal Regulation ◽  
Bursal Disease

In order to better understand differences in the outcome of infectious bursal disease virus (IBDV) infection, we inoculated a very virulent (vv) strain into White Leghorn chickens of inbred line W that was previously reported to experience over 24% flock mortality, and three inbred lines (15I, C.B4 and 0) that were previously reported to display no mortality. Within each experimental group, some individuals experienced more severe disease than others but line 15I birds experienced milder disease based on average clinical scores, percentage of birds with gross pathology, average bursal lesion scores and average peak bursal virus titre. RNA-Seq analysis revealed that more severe disease in line W was associated with significant up-regulation of pathways involved in inflammation, cytoskeletal regulation by Rho GTPases, nicotinic acetylcholine receptor signaling, and Wnt signaling in the bursa compared to line 15I. Primary bursal cell populations isolated from uninfected line W birds contained a significantly greater percentage of KUL01+ macrophages than cells isolated from line 15I birds (p < 0.01) and, when stimulated ex vivo with LPS, showed more rapid up-regulation of pro-inflammatory gene expression than those from line 15I birds. We hypothesize that a more rapid induction of pro-inflammatory cytokine responses in bursal cells following IBDV infection leads to more severe disease in line W birds than in line 15I.

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