Polymorphonuclear cells and reactive oxygen species in contagious bovine pleuropneumonia: New insight from in vitro investigations

Abstract Reactive oxygen species (ROS) are suggested to play a role in the pathogenesis of contagious bovine pleuropneumonia, a severe respiratory disorder caused by Mycoplasma mycoides subsp. mycoides ( Mmm ). The present study investigated the generation of ROS by different strains of Mmm , as well as their effect on the oxidative response of bovine neutrophils. The production of ROS was indirectly measured using a luminol-based chemiluminescence assay. Our results confirm that Mmm can produce ROS via the metabolism of glycerol, significant differences existing between African and European strains. Mmm was capable of adhering to the external surface of neutrophils. Interestingly, Mmm enhanced the respiratory burst of bovine neutrophils. This activity was particularly pronounced with the African field strain and in presence of glycerol. Taken together, our data argue in favour of a major role for neutrophils as the main source of ROS in contagious bovine pleuropneumonia

Quali-quantitative evaluation of ileal peyer's patches innervation in scrapie-free or scrapie-affected sarda breed ovines

Although Peyer's patches (PPs) and the enteric nervous system (ENS) play a key role in early sheep scrapie pathogenesis, little is known on the kinetics of ENS plexuses colonization. This study was aimed at quali-quantitatively evaluating ileal PP innervation in 29 Sarda breed ovines (12 scrapie-free, 2 months-old lambs, 4 ARQ/ARQ, 4 ARR/ARQ and 4 ARR/ARR, respectively; 12 scrapie-free, 2-4 years-old sheep, 3 ARQ/ARQ, 7 ARR/ARQ and 2 ARR/ARR, respectively; 5 ARQ/ARQ scrapie-affected sheep)

Invasive pleural malignant mesothelioma with rib destruction and concurrent osteosarcoma in a dog

A 7-year-old Dachshund was clinically examined because of a 10-day history of lameness in the left hind limb. On the basis of radiological and cytological findings, an osteosarcoma of the left acetabular region was suspected. The dog underwent a hemipelvectomy and osteosarcoma was diagnosed by subsequent histopathological examination. An immovable subcutaneous mass was noted on the left chest wall during the physical examination and non-septic neutrophilic inflammation was diagnosed by cytology. Forty days later, the dog showed signs of respiratory distress with an in-diameter increase of the subcutaneous mass up to 4 cm. Thoracic radiography and ultrasonography revealed pleural effusion and a lytic process in the fourth left rib. Furthermore, ultrasound examination revealed a mixed echogenic mobile structure with a diameter of around 2 cm floating within the pleural fluid of the left hemithorax close to the pericardium. The dog underwent surgery for an en bloc resection of the subcutaneous mass together with the fourth rib and the parietal pleura. Moreover, the left altered lung lobe, corresponding to the mobile structure detected by ultrasound, was removed. Based on cytological, histopathological, and immunohistochemical examinations, an invasive epithelioid pleural malignant mesothelioma was diagnosed

A lymphofollicular microenvironment is required for pathological prion protein deposition in chronically inflamed tissues from scrapie-affected sheep

In sheep scrapie, pathological prion protein (PrPSc) deposition occurs in the lymphoreticular and central nervous systems. We investigated PrPSc distribution in scrapie- affected sheep showing simultaneous evidence of chronic lymphofollicular, lymphoproliferative/non-lymphofollicular,and/or granulomatous inflammations in their mammary gland, lung, and ileum. To do this, PrPSc detection was carried out via immunohistochemistry and Western Blotting techniques, as well as through inflammatory cell immunophenotyping. Expression studies of gene coding for biological factors modulating the host’s inflammatory response were also carried out. We demonstrated that ectopic PrPSc deposition occurs exclusively in the context of lymphofollicular inflammatory sites, inside newly formed and well-organized lymphoid follicles harboring follicular dendritic cells. On the contrary, no PrPSc deposition was detected in granulomas, even when they were closely located to newly formed lymphoid follicles. A significantly more consistent expression of lymphotoxin α and β mRNA was detected in lymphofollicular inflammation compared to the other two types, with lymphotoxin α and β signaling new lymphoid follicles’ formation and, likely, the occurrence of ectopic PrPSc deposition inside them. Our findings suggest that, in sheep co-affected by scrapie and chronic inflammatory conditions, only newly formed lymphoid follicles provide a suitable micro-environment that supports the scrapie agent’s replication in inflammatory sites, with an increased risk of prion shedding through body secretions/excretions.[...

Scoring pleurisy in slaughtered pigs using convolutional neural networks

Diseases of the respiratory system are known to negatively impact the profitability of the pig industry, worldwide. Considering the relatively short lifespan of pigs, lesions can be still evident at slaughter, where they can be usefully recorded and scored. Therefore, the slaughterhouse represents a key check-point to assess the health status of pigs, providing unique and valuable feedback to the farm, as well as an important source of data for epidemiological studies. Although relevant, scoring lesions in slaughtered pigs represents a very time-consuming and costly activity, thus making difficult their systematic recording. The present study has been carried out to train a convolutional neural network-based system to automatically score pleurisy in slaughtered pigs. The automation of such a process would be extremely helpful to enable a systematic examination of all slaughtered livestock. Overall, our data indicate that the proposed system is well able to differentiate half carcasses affected with pleurisy from healthy ones, with an overall accuracy of 85.5%. The system was better able to recognize severely affected half carcasses as compared with those showing less severe lesions. The training of convolutional neural networks to identify and score pneumonia, on the one hand, and the achievement of trials in large capacity slaughterhouses, on the other, represent the natural pursuance of the present study. As a result, convolutional neural network-based technologies could provide a fast and cheap tool to systematically record lesions in slaughtered pigs, thus supplying an enormous amount of useful data to all stakeholders in the pig industry

Follicular dendritic cell disruption as a novel mechanism of virus-induced immunosuppression

Arboviruses cause acute diseases that increasingly affect global health. We used bluetongue virus (BTV) and its natural sheep host to reveal a previously uncharacterized mechanism used by an arbovirus to manipulate host immunity. Our study shows that BTV, similarly to other antigens delivered through the skin, is transported rapidly via the lymph to the peripheral lymph nodes. Here, BTV infects and disrupts follicular dendritic cells, hindering B-cell division in germinal centers, which results in a delayed production of high affinity and virus neutralizing antibodies. Moreover, the humoral immune response to a second antigen is also hampered in BTV-infected animals. Thus, an arbovirus can evade the host antiviral response by inducing an acute immunosuppression. Although transient, this immunosuppression occurs at the critical early stages of infection when a delayed host humoral immune response likely affects virus systemic dissemination and the clinical outcome of disease

Pathogenetic investigations on the enteric nervous system plexuses of sarda breed sheep with different PrP genotypes following oral experimental scrapie infection

We investigated the ileal myenteric (MPs) and submucosal plexuses (SMPs) of 32 Sarda breed sheep carrying different PrP genotypes (ARQ/ARQ, ARQ/AHQ, ARQ/ARR, ARR/ARR), which had been orally dosed with scrapie at 8 months of age and euthanized at definite time intervals post-infection (p.i.)

Characterizing non-tuberculous mycobacteria infection in bronchiectasis

Chronic airway infection is a key aspect of the pathogenesis of bronchiectasis. A growing interest has been raised on non-tuberculous mycobacteria (NTM) infection. We aimed at describing the clinical characteristics, diagnostic process, therapeutic options and outcomes of bronchiectasis patients with pulmonary NTM (pNTM) disease. This was a prospective, observational study enrolling 261 adult bronchiectasis patients during the stable state at the San Gerardo Hospital, Monza, Italy, from 2012 to 2015. Three groups were identified: pNTM disease; chronic P. aeruginosa infection; chronic infection due to bacteria other than P. aeruginosa. NTM were isolated in 32 (12%) patients, and among them, a diagnosis of pNTM disease was reached in 23 cases. When compared to chronic P. aeruginosa infection, patients with pNTM were more likely to have cylindrical bronchiectasis and a “tree-in-bud” pattern, a history of weight loss, a lower disease severity and a lower number of pulmonary exacerbations. Among pNTM patients who started treatment, 68% showed a radiological improvement, and 37% achieved culture conversion without recurrence, while 21% showed NTM isolation recurrence. NTM isolation seems to be a frequent event in bronchiectasis patients, and few parameters might help to suspect NTM infection. Treatment indications and monitoring still remain an important area for future research