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ABSTRACT Since 2015, virulence-associated protein N (vapN)-positive Rhodococcus equi has been isolated from pyogenic lesions in ruminants in multiple countries, including Japan, supporting the widespread distribution of this pathogen in ruminants, and suggesting that VapN is responsible for the pathogenicity of this infection. However, no immunological diagnostic method has been established for this infection. In this study, we attempted to produce anti-VapN monoclonal antibodies and apply them to immunostaining methods. Mice were immunized intraperitoneally or subcutaneously with 5 µg of recombinant VapN (rVapN). After cell fusion and cloning by limiting dilution, we generated three anti-VapN antibody-producing hybridomas (4H4, 5C3, and 5G10). Next, VapN-based immunostaining was performed using a mouse model inoculated with rVapN, the JCM94-3 (VapN-producing) strain, or the JID03-27 (low-producing) strain. Positive reactions were observed in necrotic lesions in the liver and spleen, especially in the rVapN-treated and JCM94-3-treated groups. Immunostaining of goats (n = 2) and cattle (n = 3) presumed to be infected with vapN-positive R. equi was also positive in organs carrying necrotic lesions including the lungs, lymph nodes, abomasum, and ribs. The reactivity of immunostaining differed among the antibodies, with the 4H4 antibody exhibiting the best reactivity and allowing detection at low concentrations. However, the reactivity of the other two antibodies was improved by antigen retrieval treatment. Several known diseases cause necrotizing granuloma formation, and the immunological diagnostic method established in this study can be used to distinguish R. equi infection from similar diseases or identify infection in previously missed cases. IMPORTANCE Rhodococcus equi can cause infection in ruminants, and its pathogenicity is suggested to be associated with VapN. Despite its wide distribution, no immunological diagnostic method has been developed for VapN-producing R. equi. Against this background, we attempted to develop monoclonal antibodies targeting VapN and assess their application in immunostaining. In the study, mice were immunized with recombinant VapN, and cell fusion and cloning by limiting dilution permitted the generation of three antibody-producing hybridomas. The utility of the antibodies produced from the hybridomas in immunostaining was demonstrated using an infected mouse model, and the antibodies were further applied to previously reported cases of R. equi infection in goats and cattle. Although the 4H4 antibody induced the strongest reactions, the reactivity of two other antibodies was improved by antigen retrieval. Our monoclonal antibodies will be utilized to support the definitive diagnosis of suspected R. equi infection, including cases that were previously missed.

Rhodococcus equi is a saprophytic soil bacterium and intracellular pathogen that causes refractory suppurative pneumonia in foals and has emerged as a pathogenic cause of zoonotic disease. Several studies have reported human infections caused by R. equi harboring a recently described third type of virulence plasmid, the ruminant-associated pVAPN, which carries the vapN virulence determinant. Herein, we analyzed pathogenicity and genomic features of nine vapN-harboring R. equi isolated from human patients with and without HIV/AIDS. Four of these strains showed significant VapN production and proliferation in cultured macrophages. These strains were lethally pathogenic after inoculation with 1.0 × 108 CFU in mice and reproduced a necrotizing granulomatous inflammation in the liver and spleen similar to that observed in humans. Additionally, we determined entire genome sequences of all nine strains. Lengths of sequences were 5.0–5.3 Mbp, and GC contents were 68.7 %–68.8 %. All strains harbored a 120- or 125-kbp linear plasmid carrying vapN (Type I or Type II pVAPN) classified on the basis of differences in the distal sequences on the 3′ side. Interestingly, VapN production differed significantly among strains harboring nearly identical types of pVAPN with variation limited to several SNPs and short base pair indels. The pVAPN sequences possessed by the VapN-producing strains did not retain any common genetic characteristics, and more detailed analyses, including chromosomal genes, are needed to further elucidate the VapN expression mechanism.

To study the genetic diversity of enterovirus G (EV-G) among Japanese pigs, metagenomics sequencing was performed on fecal samples from pigs with or without diarrhea, collected between 2014 and 2016. Fifty-nine EV-G sequences, which were >5,000 nucleotides long, were obtained. By complete VP1 sequence analysis, Japanese EV-G isolates were classified into G1 (17 strains), G2 (four strains), G3 (22 strains), G4 (two strains), G6 (two strains), G9 (six strains), G10 (five strains), and a new genotype (one strain). Remarkably, 16 G1 and one G2 strain identified in diarrheic (23.5%; four strains) or normal (76.5%; 13 strains) fecal samples possessed a papain-like cysteine protease (PL-CP) sequence, which was recently found in the USA and Belgium in the EV-G genome, at the 2C-3A junction site. This paper presents the first report of the high prevalence of viruses carrying PL-CP in the EV-G population. Furthermore, possible inter- and intragenotype recombination events were found among EV-G strains, including G1-PL-CP strains. Our findings may advance the understanding of the molecular epidemiology and genetic evolution of EV-Gs.

While numerous scientific studies have suggested the usefulness of autopsy imaging (Ai) in the field of human forensic medicine, the use of imaging modalities for the purpose of veterinary forensics is currently scant. The current study performed Ai on suspicious dead animals requested by the police department to determine their cause of death. Radiography and/or computed tomography and/or magnetic resonance imaging were performed on 39 suspicious dead animals before necropsy. After diagnostic imaging, pathological examination was performed, with drug testing added as needed. Among the 39 cases, 28, 6, 3, 1, and 1 involved cats, dogs, rabbits, a ferret, and a pigeon, respectively. The major Ai findings included skull and rib fractures, subcutaneous emphysema, pneumothorax, pneumoperitoneum, diaphragmatic hernia, and abdominal rupture. The leading causes of death, determined comprehensively via Ai and pathological reports and drug test results, included traumatic impact, blood loss, poisoning, suffocation, tension pneumothorax, starvation, and drowning, all of which have been strongly suspected to indicate animal abuse by humans. All eight cases of skull fractures and all five cases of poisoning, including suspected poisoning, were of cats. As the numbers of dogs and cats in Japan are almost equal, violence against cats may occur more frequently than dogs. Ai can be a valuable examination tool for veterinary forensic cases. As computed tomography is useful for ruling out fractures that screening computed tomography before necropsy is a more practical option for veterinary forensics. [ABSTRACT FROM AUTHOR]

A Holstein calf was born with a large protruding right eye and a central corneal opacity. Enucleation was the first choice of treatment. The calf had a good prognosis and was raised for milking purposes. Macroscopically, the enucleated eye was characterized by the protruded cornea, adherence of the iris to the central posterior cornea and aphakia. Microscopically, central corneal thickening and a defect in the endothelium and Descemet's membrane were observed. These data suggest that this represents a case of unilateral anterior segment dysgenesis consistent with congenital corneal staphyloma with Peters' anomaly and aphakia. Neither a mutation of the WFDC1 gene in multiple ocular defects nor any other identifiable cause for ocular anomalies was detected. [ABSTRACT FROM AUTHOR]

A 14-month-old Japanese Black heifer presented with unilateral epistaxis and mild swelling of the right face. Radiography revealed a mass with increased radiopacity on the right side of the nasal bridge, extending to the left side. Intranasal endoscopy confirmed a large tumor-like structure protruding into the nasal cavity. Following euthanasia, cranial computed tomography (CT) was performed, revealing a tumor 24.3 x 17.5 x 14.8 cm in size. The tumor occupied the entire right nasal cavity and the frontal and sphenoid sinuses. Histopathological examination revealed that the tumor consisted of well-differentiated trabecular bones and loose connective tissue. Based on these findings, a diagnosis of osteoma was established. This report describes a case of osteoma with an acute course in a Japanese Black heifer. [ABSTRACT FROM AUTHOR]

In this report, we describe a case of lipomatosis in the left parotid gland of an eight-year-old female Shetland sheepdog and review the relevant literature. Preoperative diagnosis of lipomatosis with Tru-Cut biopsy presented difficulties in this case. The postoperative diagnosis was based on the gross appearance of a non-infiltrative, circumscribed swollen mass in the parotid gland and the histological appearance of normal adipocytes that infiltrated into the parotid gland without involving surrounding structures. Additionally, flotation of the whole parotid gland in formalin solution together with well-maintained residual lobulation and a well-maintained configuration on the cut surface were identified as subsidiary characteristics of lipomatosis of the parotid gland. Lipomatosis of the parotid gland has been rarely reported in dogs and is a poorly understood condition. [ABSTRACT FROM AUTHOR]

Two captive female Asian elephants (Elephas maximus) in Thailand were euthanatized after prolonged recumbency, weakness, and unresponsive treatment. Necropsy revealed multinodular masses of 5-10 cm in diameter which were irregular, large, white and firm in consistency scattered throughout the uterine horns and uteri of both the elephants. Histologically, the tumors displayed mildly pleomorphic, spindle-shaped cells arranged in interlacing pattern interpreted as muscle bundles. The bundles of the muscle cells were interspersed by small amounts of collagen fibers and blood vessels. For immunohistochemistry, the tumor cells showed diffuse positivity for vimentin, desmin, and smooth muscle actin. Based on the pathological results, uterine leiomyomas were diagnosed. This study describes the morphology and immunohistochemical characteristics of the uterine smooth muscle tumor in Asian elephants. [ABSTRACT FROM AUTHOR]

The article discusses a case report of a 4-year-old, castrated 4.2-kg Scottish fold cat with recurrent epistaxis. It mentions that after first presentation computed tomography angiography (CTA) was performed and Caudal rhinoscopy revealed excessive and tortuous vessels in the nasopharynx. It further mentions that diathermocoagulation was attempted with a diode laser, at 93 day after first presentation.

The article describes the case of a three-year-old wire-haired fox terrier which was experiencing fever, thrombocytopenia, and crusting dermatitis. The terrier was diagnosed with canine pemphigus foliaceus (PF) with immune-mediated thrombocytopenia (IMT). It also discusses the effectiveness of systemic immunosuppressive therapy, direct immunofluorescence (IF), and the more severe pemphigus vulgaris.

The article describes the case of an indoor 3-year-old castrated male Maltese dog with generalized ulcerative dermatitis that was admitted to the Veterinary Teaching Hospital in Azabu University in Japan. The dog underwent an antimicrobial susceptibility testing under the Clinical Laboratory Standards Institute method. It discusses cutaneous sterile pyogranuloma/granuloma syndrome (SPGS), the efficacy of fosfomycin, and the use of immunofluorescence.

The article presents a case study of a seven-year old intact female dachshund with a weight of 4 kilograms (kg) brought at the Azabu University Veterinary Hospital in October 2006. The dog was diagnosed with intractable immune-mediated hemolytic anemia (IMHA) and hyperplastic suppurative gingivitis and was treated with cyclosporine A (CsA). Moreover, canine IMHA is discussed.