Death Of Infected Animals Research Articles

Epidemiology and risk factors of lumpy skin disease outbreak in cattle in the north-west area of Bangladesh

Lumpy skin disease (LSD) is an acute viral disease of cattle that recently emerged in Bangladesh that negatively impacts livestock by reducing animal production, increasing management costs, and death of infected animals. Recently, Bangladesh has faced the ominous effects of LSD, like other countries. Because of this pressing concern, the present cross-sectional study was undertaken to determine the infection status and risk factors of LSD outbreaks from January to December 2023 in Bangladesh’s northwest area. A total of 2858 cattle from various randomly selected farms were surveyed. The diagnosis was made on the basis of clinical inspection, clinical history, and owner complaints. The overall attack rate, mortality, and case fatality were 37.6%, 2.8%, and 7.5%, respectively, but in calves (≤1 month), the attack rate, mortality, and case fatality were 44.3%, 9.3%, and 21.3%, respectively. The infection status was discussed based on age, sex, breed, genotype, health status, immune status, coat color, farm size, farming system, separation of affected animals, separation place, use of common utensils, introduction of new cattle, use of vaccine and season of the year. Among them, age, sex, breed, health status, coat color, farm size, farming system, use of common utensils, and introduction of new cattle have no significant relationship with LSD outbreaks, but in calves (≤ 1 year), age has a significant association with the occurrence of LSD. The risk factor analysis revealed that the outbreaks of LSD were significantly (p<0.05) associated with genotypes, immune status, separation place, vaccination status of farm, and season of the year. The findings of the present study could provide useful epidemiological data on risk factors associated with LSD to livestock owners, field veterinarians, and government-level livestock regulators, which will help formulate prevention and control strategies and minimize the negative impact of LSD on cattle farming.

In vitro Anthelmintic Activity of Icacina trichantha Leaf Crude Extract and Fractions on Haemonchus contortus

Haemonchus contortus is an important gastrointestinal parasite of ruminants, which causes anaemia, submandibular oedema, progressive weight loss, weakness and the death of infected animals. This study evaluates the in vitro ovicidal and larvicidal activity of Icacina trichantha leaf crude extract and fractions against the parasite H. contortus eggs and larvae. Phytochemical analysis of the crude extract was carried out using standard procedures to determine the metabolites contained in the plant. The in vitro anthelmintic activity of the crude extract and fractions was determined using egg hatch inhibition assay (EHA) and larval development inhibition assay (LDA), while albendazole was the positive control. The extract of I. trichantha leaves inhibited hatching of eggs and larval development of H. contortus in a dose graded response. The concentrations of 0.78, 1.56, 3.12, 6.25 and 12.5 mg/ml of the crude extract and fractions showed the positive inhibitory effects of the ovicidal and larvicidal on H. contortus, and this compared positively with the anthelmintic activity of albendazole. At the concentration of 12.5 mg/ml, the crude extract, fractions and albendazole produced 100% ovicidal and larvicidal inhibitory effects on H. Contortus, except for n-butanol and ethyl acetate fractions, which inhibited 98% and 99.8% of egg hatching and larval development, respectively. However, the crude extract and fractions’ activity compared statistically with albendazole, with no significant (p>0.05) difference. Therefore, the results obtained from this study showed that all the tested extracts possess anthelmintic compounds that warrant further in vivo evaluation for safety and toxicity profiles.

MIR337-3p Enhances Mycobacterial Pathogenicity Involving TLR4/MYD88 and STAT3 Signals, Impairing VDR Antimicrobial Response and Fast-Acting Immunity.

Active form of vitamin D (VitD) enhances human innate immunity against Mycobacterium tuberculosis (Mtb) infection. Our previous studies showed that MIR337-3p was highly expressed in lymphocytes of tuberculosis (TB) patients. Here, we identified the mechanism of MIR337-3p in the regulation of fast-acting anti-TB immunity by inhibiting VitD-dependent antimicrobial response pathways. While high-level MIR337-3p expression was induced by mycobacterial infection in cellular models and mice, TB patients exhibited significantly increased MIR337-3p in CD14+ monocytes/macrophages, innate-like Vγ2+ T cells, and CD8+ lymphocytes containing natural killer (NK)/innate lymphoid cells. MIR337-3p promoted the mycobacterial entry/infection and replication/growth in host target cells: macrophages and lung epithelial cells. Such MIR337-3p-enhanced pathogenicity coincided with the MIR337-3p depression of VitD-dependent antimicrobial response of cytochrome P450, family 27, subfamily b, polypeptide 1 (CYP27B1)/Beta-defensin 4 (DEFB4A)/ cathelicidin antimicrobial peptide CAMP pathways. Surprisingly, single MIR337-3p species could specifically target both the Toll-like receptor 4 (TLR4) and signal transducer and activator of transcription 3 (STAT3) 3′-untranslated regions (UTRs) to depress the TLR4/MYD88 and STAT3 signals and impair either of the two signals inhibiting the VitD-dependent antimicrobial pathways in macrophages. Concurrently, human peripheral blood mononuclear cells (PBMCs) expressing high-level MIR337-3p exhibited a reduced ability of innate cell populations to mount fast-acting cellular immunity against intracellular mycobacterial infection. Furthermore, a higher expression of Mir337-3p after mycobacterial infection of mice coincided with much greater colony-forming unit (CFU) counts in lungs and even the death of infected animals, whereas Mir337-3p inhibitor treatment of infected mice reduced Mir337-3p levels and reversed Mir337-3p-mediated increases in CFU counts. Thus, TB-driven single MIR337-3p species could specifically target/impair both TLR4/MYD88 and STAT3 activation signals, inhibiting VitD-dependent antimicrobial response and fast-acting anti-TB immunity, leading to enhanced pathogenicity.

The anthelmintic potentials of medicinal plant extracts and an isolated compound (rutin, C27H30O16) from Terminalia catappa L. against Gastrothylax crumenifer

Paramphistomosis is a pathogenic disease that occurs frequently in tropical and subtropical countries including Thailand. This disease is affected in the parasites causing severe gastrointestinal disorders and death in infected animals. In the present study, we examined the anthelmintic efficacy of albendazole (ABZ) and crude plant extracts from barks of Bombax ceiba L., Diospyros rhodocalyx Kurz. and Vitex glabrata R.Br., and leaves of Terminalia catappa L. and Cassia alata L. against Gastrothylax crumenifer. The hightest anthelmintic activity on the parasites after 24 h incubation was observed in the n-butanol extract of T. catappa leaf. In this study, fractionation bioassay of n-butanol extract of T. catappa leaf was conducted to both separation and discrimination of rutin served as a new efficient compound (LC50 = 28.96; LC90 = 88.75 μg/mL) against G. crumenifer. This compound was confirmed by 1H nuclear magnetic resonance (1H NMR), 13C NMR, infrared (IR) and ultraviolet (UV) spectra as well as mass spectra data. The rutin-treated parasites with all dosages showed swift decrease of the motility and the relative motility (RM) and survival index (SI) were decreased obviously from 3 h until flukes were killed after 12 h of incubation. When observed with light microscopy, the parasites showed the earliest change in a limited region of the tegument. When observed by scanning electron microscopy, the parasites’ tegument exhibited similar sequences of surface changes after treatments with rutin and ABZ, but less severity in ABZ treatment. The sequences of changes comprised swelling of folds and ridges, formation of blebbing, rupturing of blebs, erosions, lesions and the tegument demolition. Hence, rutin could be considered as the potential anthelmintic agent for treatment of paramphistomosis.

Label-Free Electrochemical Detection of DNA Hybridization Related to Anthrax Lethal Factor by using Carbon Nanotube Modified Sensors

Background: Anthrax Lethal Factor (ANT) is the dominant virulence factor produced by B. anthracis and is the major cause of death of infected animals. In this paper, pencil graphite electrodes GE were modified with single-walled and multi-walled carbon nanotubes (CNTs) for the detection of hybridization related to the ANT DNA for the first time in the literature. Methods: The electrochemical monitoring of label-free DNA hybridization related to ANT DNA was explored using both SCNT and MCNT modified PGEs with differential pulse voltammetry (DPV). The performance characteristics of ANT-DNA hybridization on disposable GEs were explored by measuring the guanine signal in terms of optimum analytical conditions; the concentration of SCNT and MCNT, the concentrations of probe and target, and also the hybridization time. Under the optimum conditions, the selectivity of probe modified electrodes was tested and the detection limit was calculated. Results: The selectivity of ANT probes immobilized onto MCNT-GEs was tested in the presence of hybridization of probe with NC no response was observed and with MM, smaller responses were observed in comparison to full-match DNA hybridization case. Even though there are unwanted substituents in the mixture samples containing both the target and NC in the ratio 1:1 and both the target and MM in the ratio 1:1, it has been found that ANT probe immobilized CNT modified graphite sensor can also select its target by resulting with 20.9% decreased response in comparison to the one measured in the case of full-match DNA hybridization case Therefore, it was concluded that the detection of direct DNA hybridization was performed by using MCNT-GEs with an acceptable selectivity. Conclusion: Disposable SCNT/MCNT modified GEs bring some important advantages to our assay including easy use, cost-effectiveness and giving a response in a shorter time compared to unmodified PGE, carbon paste electrode and glassy carbon electrode developed for electrochemical monitoring of DNA hybridization. Consequently, the detection of DNA hybridization related to the ANT DNA by MCNT modified sensors was performed by using lower CNT, probe and target concentrations, in a shorter hybridization time and resulting in a lower detection limit according to the SCNT modified sensors. In conclusion, MCNT modified sensors can yield the possibilities leading to the development of nucleic acid sensors platforms for the improvement of fast and cost-effective detection systems with respect to DNA chip technology.

Biomarkers of the Caseous Lymphadenitis in Sheep by NMR-Based Metabolomics

Caseous Lymphadenitis (CLA) is a disease that affects animals, such as sheep, whose etiologic agent is Corynebacterium pseudotuberculosis. In sheep, it causes enormous damages, expressed through a reduction in milk, meat and wool production, or death of infected animals, and, also, difficulties in sterilizing infected animals habitats. Another problem in the control of this disease is its late diagnosis. Thus, we present the pioneer results on NMRbased metabolomics applied in CLA with the aim to detect blood serum profile alterations provoked by a pathogen in C. pseudotuberculosis seropositive sheep. We have compared two types of serum samples: The ones taken from the seropositive animals, which we called infected, and others taken from the seronegative (healthy) animals. Significant metabolomics profile changes occurred in the spectral regions δ: 0.20 to 2.20; 3.20 to 4.40 and 6.40 to 8.00 that refer to hydrogen atoms of proteins, organic acids, alcohols, lipids and some amino acids, correspondingly. When applying chemometrics, a significative separation of 59 serum samples into two groups, sick and healthy animals, was achieved. Additionally, key-metabolites that were only present in the group of sick animals and that can be considered as exclusively bacteria derived were pointed as possible biomarkers for CLA. Therefore, these data might contribute to the development of a non-invasive NMR-based diagnostic method, as well as to bring new insights into the development of new immunoprohylaxis tools.

The application of PCR based methods in diagnostics of some viral infections of swine

Viral infections of swine cause significant economic losses in swine husbandry. They manifest in death of infected animals of different ages or in decreased productivity during the manufacturing process. Having that in mind, rapid and reliable diagnostics of viral infections is crucial in the prevention of disease transmission in herds of swine. Today, virological laboratories all over the world use different diagnostic methods such as isolation of virus in cell lines, ELISA, virus neutralization test, direct and indirect immunofluorescence and hemagglutination and hemagglutination inhibition tests. Virus isolation, virus neutralization test and some other standard virological methods are time consuming and rather expensive, therefore, molecular methods such as conventional PCR, RT - PCR, real-time PCR and direct sequencing methods are applied worldwide as fast and reliable. Their application is especially necessary for the detection of viruses which cannot be identified by using standard virological methods.

Macrocyclic lactones and their relationship to the SNPs related to benzimidazole resistance

Haemonchus contortus is an abomasal nematode of ruminants that is widely present across the world. Its ability to cause death of infected animals and rapidly develop anthelmintic resistance makes it a dangerous pathogen. Ivermectin (IVM) and moxidectin (MOX) are macrocyclic lactones (MLs). They have been successfully used to treat parasitic nematodes over the last three decades. A genetic association between IVM selection and single nucleotide polymorphisms (SNPs) on the β-tubulin isotype 1 gene was reported in H. contortus. These SNPs result in replacing phenylalanine (F, TTC) with tyrosine (Y, TAC) at position 167 or 200 on the β-tubulin protein. Recently we reported a direct interaction of IVM with α- and β-tubulin. It had been hypothesized that the SNPs (F167Y and F200Y) may change tubulin dynamics and directly affect IVM binding. The goal of the current study was to observe the effects of SNPs (F167Y and F200Y) on tubulin polymerization and IVM binding. It was also of interest to evaluate the differences between IVM and MOX on tubulin polymerization. We conclude that the SNPs cause no difference in the polymerization of wild and mutant tubulins. Furthermore, neither of the SNPs reduced IVM binding. Varying results were obtained in the degree of polymerization of parasitic and mammalian tubulin for IVM and MOX, i.e., the extent of polymerization was greater for IVM compared with MOX, for H. contortus tubulin, and vice versa for mammalian tubulin. Molecular modeling showed that IVM and MOX docked into the taxane binding pocket of both mammalian and parasitic wild type and mutant tubulins. However the binding was stronger for mammalian tubulin as compared to parasitic tubulin.

Fexinidazole: A Potential New Drug Candidate for Chagas Disease

BackgroundNew safe and effective treatments for Chagas disease (CD) are urgently needed. Current chemotherapy options for CD have significant limitations, including failure to uniformly achieve parasitological cure or prevent the chronic phase of CD, and safety and tolerability concerns. Fexinidazole, a 2-subsituted 5-nitroimidazole drug candidate rediscovered following extensive compound mining by the Drugs for Neglected Diseases initiative and currently in Phase I clinical study for the treatment of human African trypanosomiasis, was evaluated in experimental models of acute and chronic CD caused by different strains of Trypanosoma cruzi.Methods and FindingsWe investigated the in vivo activity of fexinidazole against T. cruzi, using mice as hosts. The T. cruzi strains used in the study were previously characterized in murine models as susceptible (CL strain), partially resistant (Y strain), and resistant (Colombian and VL-10 strains) to the drugs currently in clinical use, benznidazole and nifurtimox. Our results demonstrated that fexinidazole was effective in suppressing parasitemia and preventing death in infected animals for all strains tested. In addition, assessment of definitive parasite clearance (cure) through parasitological, PCR, and serological methods showed cure rates of 80.0% against CL and Y strains, 88.9% against VL-10 strain, and 77.8% against Colombian strain among animals treated during acute phase, and 70% (VL-10 strain) in those treated in chronic phase. Benznidazole had a similar effect against susceptible and partially resistant T. cruzi strains. Fexinidazole treatment was also shown to reduce myocarditis in all animals infected with VL-10 or Colombian resistant T. cruzi strains, although parasite eradication was not achieved in all treated animals at the tested doses.ConclusionsFexinidazole is an effective oral treatment of acute and chronic experimental CD caused by benznidazole-susceptible, partially resistant, and resistant T. cruzi. These findings illustrate the potential of fexinidazole as a drug candidate for the treatment of human CD.

Disseminated disease severity as a measure of virulence of Mycobacterium tuberculosis in the guinea pig model

Virulence is the measure of pathogenicity of a microorganism as determined by its ability to invade host tissues and to produce severe disease. In the low-dose aerosol guinea pig model the virulence of multiple strains of Mycobacterium tuberculosis was determined by measuring time of survival, bacterial loads in target organs, and the severity of pulmonary and extra-pulmonary lesions. Erdman K01, CSU93/CDC1551 and HN878 had shorter survival times compared to the common laboratory strain H37Rv. After 30 days of the infection bacilli had disseminated from the lungs resulting in microscopically visible lesions in peribronchial lymph nodes, peripancreatic lymph nodes, spleen, liver, pancreas, adrenal and heart. The extent of the lesion necrosis paralleled virulence when survival times were used as a measure as Erdman K01 and the two clinical isolates caused more necrosis and resulted in sooner death in infected animals than the H37Rv. The extent of extra-pulmonary lesion necrosis was a better predictor of virulence than the number of viable bacilli in the tissue. Overall, this study emphasizes the point that extra-pulmonary disease is a prominent feature of the guinea pig model and dissemination to organs not normally assayed such as the heart and adrenal glands should be taken into account in the assessment of the disease process.

Protective Antigen as a Correlative Marker for Anthrax in Animal Models

The most aggressive form of anthrax results from inhalation of airborne spores of Bacillus anthracis and usually progresses unnoticed in the early stages because of unspecific symptoms. The only reliable marker of anthrax is development of bacteremia, which increases with disease progress. Rapid diagnosis of anthrax is imperative for efficient treatment and cure. Herein we demonstrate that the presence and level of a bacterial antigen, the protective antigen (PA), a component of B. anthracis toxins, in host sera can serve as a reliable marker of infection. This was tested in two animal models of inhalation anthrax, rabbits and guinea pigs infected by intranasal instillation of Vollum spores. In both models, we demonstrated qualitative and quantitative correlations between levels of bacteremia and PA concentrations in the sera of sick animals. The average time to death in infected animals was about 16 h after the appearance of bacteremia, leaving a small therapeutic window. As the time required for immunodetection of PA can be very short, the use of this marker will be beneficial for faster diagnosis and treatment of inhalation anthrax.

Minocycline Impedes African Trypanosome Invasion of the Brain in a Murine Model

Passage of Trypanosoma brucei across the blood-brain barrier (BBB) is a hallmark of late-stage human African trypanosomiasis. In the present study we found that daily administration of minocycline, a tetracycline antibiotic, impedes the penetration of leukocytes and trypanosomes into the brain parenchyma of T. brucei brucei-infected C57BL/6 mice. The trypanosome-induced astrocytic and microglial reactions were reduced in the minocycline-treated mice, as were the levels in the brain of transcripts encoding adhesion molecules intercellular adhesion molecule 1 (ICAM-1) and endothelial-leukocyte adhesion molecule 1 (E-selectin); the inflammatory cytokines tumor necrosis factor alpha, interleukin-1alpha (IL-1alpha), IL-1beta, IL-6, and gamma interferon; and matrix metalloprotease 3 (MMP-3), MMP-8, and MMP-12. Loss of weight occurring during infection with T. b. brucei was not observed after treatment of the mice with minocycline; these mice also survived longer than nontreated mice. Invasion of trypanosomes and leukocytes into the brain parenchyma most likely triggered the loss of weight and death of infected animals, since minocycline did not affect the growth of T. b. brucei either in vitro or in vivo or the levels of the transcripts encoding the cytokines and MMPs in the spleen. In conclusion, our data show that T. b. brucei invasion of the brain is related to that of leukocytes and that minocycline can ameliorate the disease in trypanosome-infected mice.

τ (tau) virus infection of Carcinus mediterraneus: Histology, cytopathology, and experimental transmission of the disease

The τ (tau) virus was isolated from diseased specimens of the crab Carcinus mediterraneus from the Mediterranean coast. It shares the general characteristics of the nonoccluded baculoviruses, but differs by its bow-shaped structure. Lesions are located in epithelial cells of the hepatopancreas and midgut. Pathological changes of the cells were characterized by enlarged nuclei associated with cytoplasmic vacuolization. Infected nuclei contain both rod-shaped and bow-shaped enveloped particles with mean dimensions of 350 nm in length and 80 nm in diameter. Virus transmission experiments resulted in death of infected animals which revealed typical signs of the disease.

Experimental Infection of the Squirrel Monkey (Saimiri sciureus) with Plasmodium falciparum

Seventy-six squirrel monkeys, Saimiri sciureus, caught in Guyana and French Guiana, were examined for their susceptibility to infection with a strain of Plasmodium falciparum. Twenty-nine serial transfers were performed, both in splenectomized and intact animals. After a period of "adaptation," the strain became more virulent for the squirrel monkey and high parasitemias were obtained in splenectomized animals. Frequently, such infections led to the death of infected animals. In intact squirrel monkeys, a consistent parasitemia was observed in most animals, but with a less regular pattern and a lower level of infection. Cultivation of infected erythrocytes from squirrel monkeys and human erythrocytes confirmed that the parasite had kept its infectivity for human cells after a long period of serial syringe-transfers in the squirrel monkey, and tht the virulence for the Saimiri remained unchanged after 1-mo, in vitro progagation in human erythrocytes. All erythrocytic forms of the schizogonic cycle were observed in the bloodstream, and there was a certain synchronicity of the cycle. Gametocytes were not detected in infected animals nor in in vitro cultures derived from a parasitized squirrel monkey. Our results indicate that all the squirrel monkey can be a useful host in the laboratory for studies on P. falciparum, and it may become more important as the supply of other species of monkeys diminishes.