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In January 2019, high mortalities were reported among African Penguins (Spheniscus demersus) in a breeding colony on Halifax Island, Namibia, Africa. Analysis of samples by reverse transcription quantitative PCR indicated the presence of highly pathogenic avian influenza (HPAI) subtype H5N8. Sequence analysis of the hemagglutinin and neuraminidase genes confirmed the presence of the virus in the birds and its high similarity to HPAI subtype H5N8 identified in South Africa in 2017. There have been no previous reports of HPAI H5N8 in Namibia.

Additional file 3. Double-labelling indirect immunofluorescence (DLIIF) protocols.

The healing of wounds located on the equine distal limbs can often be impaired, which can result in exuberant granulation tissue and its associated aesthetic alteration and functional failures. Although a number of therapies have been developed and assessed, the treatment of these wounds still presents challenges. This report describes the treatment of exuberant granulation tissue in a horse using an intra-lesional injection of 4% formaldehyde solution. The successful outcome of this treatment suggests that further investigations are required in order to better evaluate its efficacy, as well as the incidence and the severity of any adverse reaction.

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.

Contagious bovine pleuropneumonia (CBPP) is a severe disease caused by Mycoplasma mycoides subsp. mycoides (Mmm). Knowledge on CBPP pathogenesis is fragmented and hampered by the limited availability of laboratory animal and in vitro models of investigation. The purpose of the present study is to assess respiratory explants as useful tools to study the early stages of CBPP. Explants were obtained from trachea, bronchi and lungs of slaughtered cattle, tested negative for Mycoplasma spp. and for the major bacterial and viral respiratory pathogens. The interaction of Mmm with explant cells was studied by immunohistochemistry (IHC), double-labelling indirect immunofluorescence (DLIIF) and laser scanning confocal microscopy (LSCM). Mmm capability to survive and proliferate within the explants was evaluated by standard microbiological procedures. Finally, the putative cellular internalization of Mmm was further investigated by the gentamicin invasion assay. IHC and DLIIF indicated that Mmm can colonize explants, showing a marked tropism for lower airways. Specifically, Mmm was detected on/inside the bronchiolar and alveolar epithelial cells, the alveolar macrophages and the endothelial cells. The interaction between Mmm and explant cells was abolished by the pre-incubation of the pathogen with bovine anti-Mmm immune sera. Mmm was able to survive and proliferate in all tracheal, bronchial and lung explants, during the entire time course of the experiments. LSCM and gentamicin invasion assay both confirmed that Mmm can enter non-phagocytic host cells. Taken together, our data supports bovine respiratory explants as a promising tool to investigate CBPP, alternative to cattle experimental infection. Electronic supplementary material The online version of this article (10.1186/s13567-017-0500-z) contains supplementary material, which is available to authorized users.

SUMMARYWest Nile virus (WNV) circulation dynamics in the context of the urban environment is not yet elucidated. In this perspective, three groups of eight rock pigeons (Columbia livia) were inoculated with three WNV lineage 1 strains isolated in Italy between 2009 and 2012. The pigeons did not develop any clinical signs consistent with WNV acute infection. All animals seroconverted and shed virus up to 15 days post-infection by the oral or cloacal routes. In all infected groups viraemia lasted for 4 days post-infection. No WNV-specific gross or histological lesions were found in infected birds compared to control birds and immunohistochemistry remained constantly negative from all tissues. The reservoir competence index was also assessed and it ranged between 0·11 and 0·14. This study demonstrates that pigeons are competent reservoir hosts for Italian WNV lineage 1 circulating strains thus potentially posing a risk to the public health system.

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.

Ileal Peyer's patches (PPs) are involved early during sheep scrapie infection. This study qualitatively and semi-quantitatively evaluated ileal tract and PP innervation in 29 Sarda ovines of different age, PrP genotype and scrapie status. A prominent network of fibres was detected within PPs, mainly located in interfollicular lymphoid and stromal components. Intrafollicular fibres were rarely observed, with no apparent differences between scrapie-free and scrapie-affected animals, or among ovines carrying different PrP genotypes. In adult sheep, independent of their scrapie status, nerve fibres could be detected infrequently, close to the follicle-associated epithelium. Fibres were also detected within newly formed follicles and intrafollicular microgranulomas.

Until now, significant differences in the neurochemical pattern of enteric neurons have been demonstrated in all species studied; however, some strong similarities also occur across species, such as the occurrence of nitric oxide synthase immunoreactivity (NOS-IR) in inhibitory motor neurons to muscle. In consideration of the insufficient data regarding the enteric nervous system (ENS) of sheep, we investigated the myenteric plexus and submucosal plexus of the ovine ileum. Since the pivotal role of the ENS in the early pathogenesis of sheep scrapie, the “prototype” of prion diseases, has been suggested, we have focused our observations also on the host's PrP genotype. We have studied the morphology and distribution of NOS-IR neurons and their relationships with the enteric glia in whole-mount preparations and in cryostat sections. NOS-IR neurons, always encircled by glial processes, were located in both plexuses. Many NOS-IR fibers were seen in the circular muscle layer, in the submucosa, and in the mucosa. In the submucosa they were close to the lymphoid tissue. No differences in the distribution and percentage of NOS-IR fibers and neurons were observed among sheep carrying different PrP genotype, thus making unlikely their contribution in the determinism of susceptibility/resistance to scrapie infection.

Despite advances in diagnosis and treatment, Mycobacterium tuberculosis causes active disease in about 8 million people worldwide annually. The study of the interplay between the host and the pathogen at the site of infection in human TB may contribute to elucidate the pathogenesis of the disease. In this work, using macroarray technology and real-time PCR, we analyzed the modulation of 847 genes encoding immune-inflammatory mediators in BALF samples of patients affected by active pulmonary TB (PTB) and control patients affected by non-TB diseases. The data show that the PTB milieu contains a complex network of gene activation. Different genes with adhesive properties and involved in tissue repair and fibrosis were modulated. In TB patients, we observed the up-regulation of cytokines, including IFN-gamma and IFN-gamma pathway genes, of several apoptotic genes, and of potent transcriptional activators. These findings can contribute to elucidate the mechanisms of MTB pathogenicity in humans.

Heat shock proteins (HSPs) are strongly implicated in the control of cell growth, differentiation and biological behaviour of many human cutaneous neoplasms. To our knowledge, no data have been published in the veterinary literature concerning either normal or neoplastic skin. In this study, the immunohistochemical expression of Hsp27, Hsp72 and Hsp73 was evaluated in normal canine skin, 14 intracutaneous cornifying epitheliomas (ICE), 10 well-differentiated and 5 moderately differentiated squamous cell carcinomas (SCC). Expression was correlated with the histological degree of keratinocyte differentiation and proliferation, and investigated as to its usefulness in the differential diagnosis of these canine tumours. In normal epidermis, Hsp27 exhibited cytoplasmic labelling in the spinous and granular layers, whereas in neoplastic tissues it was detected particularly in those areas showing squamous differentiation. Hsp72 immunoreactivity was more intense in ICE and well-differentiated SCC than in normal skin; however, reduced immunolabelling was observed in moderately differentiated SCC. Unlike Hsp72, Hsp73 showed less intense labelling in ICE and well-differentiated SCC than in normal epithelium and an increased positivity in moderately differentiated SCC. These results indicate that HSP immunoreactivity differs between normal and neoplastic canine skin. Hsp27 expression seems to correlate directly with cellular differentiation; by contrast, the involvement of Hsp72/73 in proliferation and differentiation of tumour cells remains controversial. The pattern and intensity of immunolabelling of each investigated HSP did not show, however, significant differences between ICE and SCC; therefore, they do not seem to be useful in the differential diagnosis of these two canine tumours.

Summary A 14-month-old half-breed horse showed a severe lameness due to a lesion of the right forefoot which appeared completely and asymmetrically cleaved, from the solar margin to the coronary band. The horse was presented to an abattoir for slaughter and both forelimbs were collected for diagnostic investigations. The hoof lesion described herein does not fulfil the diagnostic criteria of equine polydactyly since post mortem imaging and pathological investigations ruled out the presence of supernumerary digits. Based on the clinical signs, diagnostic imaging (computed tomography) and gross examination, a diagnosis of pseudo-polydactyly was proposed. To the best of our knowledge, the features of the present case report are unique, thus widening the range of lesions observed at the level of the hoof, which is crucial for horse health and activity.

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.

Herein we describe a glioblastoma partially occupying the telencephalic portion of the left cerebral hemisphere of a Sardinian (syn. Sarda) breed ewe. Microscopically, the mass consisted of a pleomorphic spindle-shaped cell component organized as bundles and numerous small areas of round cells displaying an oligodendroglioma-like aspect. A high number of mitotic figures, large areas of necrosis surrounded by pseudopalisading glial cells, and multiple foci of dystrophic mineralization were also observed. The neoplasm was highly vascularized with glomerular vascular proliferation. Immunohistochemically, neoplastic cells proved to be strongly positive for nestin, vimentin, and olig-2, whereas they were invariably negative for synaptophysin. Few neoplastic cells and reactive astrocytes, mainly located at the edge of necrotic foci, proved to be positive for glial fibrillary acidic protein, whereas glomerular vascular proliferation was clearly positive for factor VIII and vascular endothelial growth factor. Gene sequencing analysis demonstrated homozygous p53 tumor suppressor gene ( TP53) point mutations in the DNA-binding domain located in exon 8. The presence of round cells immunoreactive for olig-2 demonstrated that this tumor is a glioblastoma with oligodendroglioma component. Our pathologic, immunohistochemical, and molecular findings largely overlap those previously reported in humans and dogs.

Enzootic pneumonia by Mycoplasma hyopneumoniae and pleuropneumonia by Actinobacillus pleuropneumoniae are among the most common and economically relevant pulmonary diseases in swine herds. We herein investigated the activity and expression of 5-lipoxygenase (5-LOX) and cyclooxygenase-2 (COX-2) in healthy and diseased porcine lungs, by means of immunohistochemical, immunochemical and biochemical assays. Diseased lungs showed a significantly higher activity and expression of 5-LOX and COX-2 in a wide range of cell types, thus suggesting the likely involvement of both enzymes in the pathogenesis of bacterial porcine pneumonia. Consistently, increased enzyme activities were paralleled by increased leukotriene B(4) (LTB(4)), a 5-LOX product and prostaglandin E(2) (PGE(2)), a COX-2 product, content in diseased versus healthy lungs.

Follicular dendritic cells (FDCs) residing within ileal Peyer's patches (PPs) are of crucial relevance for sheep scrapie early pathogenesis and subsequent scrapie prion neuroinvasion. In this study, ileal PP follicles were significantly more numerous in lambs than in adult Sarda breed sheep, with significant differences being also found in lymphoid follicle area, perimeter and FDC density. Furthermore, PrPd deposition within ileal PPs and host's PrP genotype did not significantly influence these parameters. We conclude that age significantly affects FDC density in ileal PPs from Sarda breed ovines, independently from host's scrapie status and PrP genotype.

Canine testicular tumours frequently occur and share relevant features with their human counterparts, thus being a putative model in comparative oncology. The authors present data on canine testicular tumours submitted to the Istituto G. Caporale over the last 12 years. In total, 183 testicular neoplasms were diagnosed: 108 seminomas, 37 Sertoli cell tumours, 18 interstitial Leydig cell tumours, 10 mixed tumours, 9 other primary tumours and one metastatic neoplasm. A systematic and more detailed collection of data (signalling, history, clinical signs and follow-up) enables a better evaluation of clinical and biological features of animal tumours, as well as a clear assessment of the real impact, if any, of specific intrinsic and extrinsic risk factors.

Candida albicans is among the major agents of mucous membrane mycosis in humans and animals, with systemic and deep infections observed in immunocompromised hosts. We describe a case of fatal granulomatous myocarditis caused by C albicans in a 20-day-old canary (Serinus canaria). The etiologic diagnosis was confirmed by identifying characteristic morphologic features of the organism, combined with histochemical staining, and followed by the use of ad hoc biomolecular analysis.

African horse sickness (AHS) is a vector‑borne viral disease of equids, endemic in Sub‑Saharan Africa. This article reports the clinic‑pathological and laboratory findings observed in the framework of passive surveillance during the AHS outbreaks which occurred in Namibia between 2006 and 2013. This study was conducted in the framework of the collaboration among the Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise (Teramo, Italy), the Namibian Ministry of Agriculture Water and Forestry, and the Namibian National Veterinary Association. A total of 92 horses were investigated, showing different clinical form of AHS: peracute/acute (n = 43), sub‑acute (n = 21) and mild AHS fever (n = 19). Clinical data were not available for 9 horses, because they were found dead. Pathological findings have been recorded for 35 horses. At necropsy, pulmonary and subcutaneous oedema, haemorrhages and enlargement of lymph nodes were mainly observed. Diagnosis was confirmed by laboratory testing, AHS virus (AHSV) was isolated from 50 horses and the identified serotypes were: 1, 2, 4, 6, 7, 8, and 9. The phylogenetic analysis of the S10 genome sequences segregated the Namibian AHSV strains in the same clusters of those circulating in South Africa in recent years. The description of AHS clinical, pathological, and laboratory features of AHS provided in this article is of value for differential diagnosis and control of AHS, especially in areas currently free from this disease.

In 2011, strains of West Nile Virus (WNV) belonging to lineage 1 spread for the first time in Sardinia region (Italy). In contrast to previous WNV Italian incursion, the strains were found in Culex modestus and, more surprisingly, they were able to cause severe clinical signs in the affected birds. Based on the partial sequence of the NS3 encoding gene, the Sardinian WNV strains demonstrated a high similarity with the other WNV strains recently detected in the Mediterranean Basin. Nonetheless, the 2011 Sardinian sequences were grouped in a distinct sub-cluster. Both the NS3-249P and NS3-249T genotypes were detected in the Sardinian outbreaks confirming that the co-circulation of different genotypes in the affected population might be common for WNV as for many RNA viruses. No association, however, was observed between virulence and viral genotype.

During the past decades, a growing interest has been raised in evaluating nontuberculous mycobacteria (NTM) in patients with noncystic fibrosis bronchiectasis (NCFBE). This paper reviews several aspects of the correlations between NTM and NCFBE, including pathogenesis, radiological features, diagnosis, and management. Bronchiectasis and NTM lung disease are connected, but which one comes first is still an unresolved question. The rate of NTM lung disease in NCFBE varies through the studies, from 5% to 30%. The most frequent species isolated is MAC. NCFBE patients affected by NTM infection frequently present coinfections, including both other different NTM species and microorganisms, such as P. aeruginosa. Once a diagnosis of NTM disease has been reached, the initiation of therapy is not always mandatory. NTM species isolated, patients’ conditions, and disease severity and its evolution should be considered. Risk factors for disease progression in NCFBE patients with NTM are low body mass index, cavitary disease, consolidations, and macrolide resistance at presentation.

Nocardiosis is a rare and potentially life-threatening infection caused by several species of the Nocardia genus. Most cases occur in immunocompromised patients, and a delay in establishing the diagnosis is common due to the non-specific clinical presentations and the difficulty in cultivating Nocardia. Although the majority of pulmonary nocardiosis cases are caused by Nocardia asteroides, cases of human infection due to N. farcinica are increasingly diagnosed due to recent developments in taxonomy and diagnostic methods. N. farcinica is a separate species from N. asteroides and appears to be more virulent and resistant to antibiotics. Herein, we describe the case of a 65-year-old HIV-negative immunocompromised patient with a fulminant bilateral pulmonary nocardiosis while on empirical treatment with trimethoprim/sulfamethoxazole and imipenem. Post-mortem diagnosis of N. farcinica infection was performed by means of DNA amplification and sequencing of the 65-kDa bacterial heat shock protein.