Matheus Viezzer Bianchi

Natural Infection of Wild Canids (Cerdocyon thous and Lycalopex gymnocercus) with the Intraendothelial Piroplasm Rangelia vitalii in Southern Brazil

Abstract Rangelia vitalii is a piroplasm that infects canines, causing lesions typical of a hemolytic disorder. Two wild canids, a crab-eating fox (Cerdocyon thous) and a Pampas fox (Lycalopex gymnocercus), were presented for necropsy in Setor de Patologia Veterinária at the Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil. On gross examination, both animals had pale mucosae and moderate tick infestation (Amblyomma aureolatum). There was severe splenomegaly, and the liver had a diffusely orange-reddish lobular pattern. The mesenteric lymph nodes were brownish and slightly enlarged. Structures compatible with R. vitalii were observed in the cytoplasm of endothelial cells in the liver, stomach, heart, kidney, lungs, lymph nodes, and bladder. The agent was characterized by PCR and genetic sequencing of liver samples and ticks. We show that parasitism with R. vitalii follows an epidemiologic cycle in which wild canids act as reservoirs.

Natural Outbreak of BVDV-1d–Induced Mucosal Disease Lacking Intestinal Lesions

Bovine viral diarrhea virus (BVDV) belongs to the Pestivirus genus, which is further divided into subgenotypes (1a–1u and 2a–c). When persistent infection occurs, the calf will be immunotolerant to BVDV and possibly develop mucosal disease. This study describes an outbreak of BVDV-1d–induced mucosal disease lacking intestinal lesions. Eleven calves presented with anorexia, sialorrhea, lameness, recumbency, and death. Three calves were necropsied, showing ulceration of the interdigital skin and the oral and nasal mucosa; linear ulcers in the tongue, esophagus, and rumen; and rounded ulcers in the abomasum. Microscopically, mucosa and skin had superficial necrosis, with single-cell necrosis and vacuolation in epithelial cells, and severe parakeratosis. Immunohistochemistry (IHC) showed BVDV antigen in the cytoplasm of epithelial cells in skin and mucosa. All 11 dead calves were positive upon reverse transcription-polymerase chain reaction (RT-PCR) for the detection of Pestivirus along with another 11 live calves from the herd, which were positive again by RT-PCR and IHC after a 4-week interval. Sequencing of the 5′ untranslated region and N-terminal protease showed that viruses from these 22 calves were homologous and of subgenotype BVDV-1d. Cytopathic BVDV was isolated from 8 of 11 dead calves, but only noncytopathic BVDV was isolated from the 11 live animals. The findings indicate that this was an outbreak of mucosal disease caused by BVDV-1d, with high morbidity, and lesions restricted to the upper alimentary system and skin and absent from intestine. Thus, the epidemiological and pathological features in this form of mucosal disease may be similar to vesicular diseases, including foot and mouth disease.

Canine papillomatosis: a retrospective study of 24 cases (2001-2011) and immunohistochemical characterization

Foi realizado um estudo retrospectivo de 24 casos de papilomas em caes diagnosticados no periodo de janeiro 2001 a marco de 2011, bem como a sua caracterizacao imuno-histoquimica (IHQ). Caes sem raca definida foram os mais afetados, a idade media foi de 3,1 anos, com variacao de 6 meses a 10 anos e nao houve predilecao sexual. Quanto a localizacao das lesoes, 75,0% estavam na pele, 16,7% no labio e 8,3% em palpebra. Na avaliacao histologica havia proliferacao papilar exofitica do epitelio escamoso em 87,5% e papilar endofitica (invertido) em 12,5%. O tumor era caracterizado por hiperplasia do estrato espinhoso (87,5%) com coilocitos (70,8%) e inclusoes intranucleares basofilicas palidas (8,3%); o estrato granular estava proeminente com grande quantidade de grânulos de querato-hialina (95,8%); e havia hiperqueratose do estrato corneo (100%). Na avaliacao IHQ para Papillomavirus houve marcacao nos estratos granuloso e corneo em 83,3%. Estes achados indicam que os papilomas em caes sao causados por Papillomavirus, as lesoes epiteliais sao decorrentes do efeito citopatico viral, as particulas virais estao no nucleo das celulas e corpusculos de inclusao sao raros.

Necrotizing meningoencephalitis caused by Sarcocystis falcatula in bare-faced ibis ( Phimosus infuscatus )

The infection by S. falcatula is commonly associated with respiratory disease in captive psittacine birds, with a few case reports of this protozoan causing encephalitis in wild birds. We describe the clinical, pathological, and molecular aspects of an infection by S. falcatula in a bare-faced ibis (Phimosus infuscatus). Clinically, wing paralysis and mild motor incoordination were observed. At necropsy, the telencephalic cortex showed multifocal to coalescing yellowish soft areas. Histologically, multifocal to coalescent nonsuppurative necrotizing meningoencephalitis of telencephalic cortex, cerebellum, and brainstem was observed. Necrotic areas showed multiple protozoan organism characteristics of Sarcocystis sp. schizonts in the cytoplasm of endothelial cells or lying free in the neuropil. Partial genetic sequences of the gene encoding cytochrome b (CYTB), the gene encoding the beta subunit of RNA polymerase (RPOB) and the first internal transcribed spacer (ITS-1) from Sarcocystis sp. schizonts revealed that the parasite had ITS-1 sequences that were 100% identical to the homologous alleles from Sarcocystis sp. shed by Didelphis albiventris in Brazil. RPOB and CYTB sequences were 100% identical to homologous of S. falcatula available in Genbank. Thus, this is the first report of necrotizing meningoencephalitis caused by S. falcatula in bare-faced ibis (P. infuscatus).

Piglet colibacillosis diagnosis based on multiplex polymerase chain reaction and immunohistochemistry of paraffin-embedded tissues.

Enterotoxigenic Escherichia coli (ETEC) causes diarrhea in pigs, referred to as colibacillosis. The aim of this study was to optimize multiplex polymerase chain reaction (PCR) and immunohistochemistry (IHC) analyses of paraffin-embedded material to detect pathogenic E. coli strains causing colibacillosis in pigs. Multiplex PCR was optimized for fimbriae (F18, F4, F6, F5, and F41) and toxins (types A and B heat-stable toxins [STaP and STb], heat-labile toxin [LT], and type 2 Shiga toxin [STx2e]), and IHC was optimized for an anti-E. coli polyclonal antibody. Samples (132) from pigs received between 2006 and 2014 with clinical and histopathological diagnoses of colibacillosis were analyzed. E. coli was detected by IHC in 78.7%, and at least one virulence factor gene was detected in 71.2%. Pathogenic strains of ETEC with at least one fimbria and one toxin were detected in 40% of the samples in multiplex PCR. The most frequent virulence types were F18-STaP (7.5%), F18-STaP-STb (5.7%), and F4-STaP (3.8%). A statistically significant association was noted between virulence factors F4, F18, STaP, and STb and positive immunostaining results. Colibacillosis diagnosis through multiplex PCR and IHC of paraffin-embedded tissues is a practical approach, as samples can be fixed and stored for long periods before analysis.

Intra-abdominal fungal pseudomycetoma in two cats

BACKGROUND Pseudomycetomas are deep cutaneous to subcutaneous lesions caused by Microsporum canis mainly described in Persian cats, with few reports of intra-abdominal location. This report describes the clinical signs and lesions of intra-abdominal pseudomycetomas caused by M. canis in two Persian cats. CASE REPORT Two Persian cats with a history of previous laparotomy (ovariohysterectomy and nephrostomy) and fecal impaction were examined. Cat #1 was euthanized and subjected to necropsy, histopathology and mycological evaluation. Cat #2 presented with chronic dermatophytosis, and an intra-abdominal mass, that was subjected to histopathology evaluation. Cat #1 presented at necropsy a white-grayish, firm mass (6cm×3.5cm×2.8cm) in the uterine cervix. Cat #2 presented a firm whitish mass (6.5cm×1.5cm×0.5cm) located close to the left kidney. Histologically, both masses contained multifocal granules with hyphae and spores surrounded by Splendore-Hoeppli reaction, with a pyogranulomatous inflammatory infiltrate and fibrous connective tissue proliferation in the periphery. Hyphae and spores exhibited marked Grocott and periodic acid-Schiff staining. M. canis was identified by fungal isolation in cat #1. CONCLUSIONS Pseudomycetoma should be considered as a differential diagnosis in cats, especially in Persian cats presenting with an intra-abdominal mass. Entrance of the agent into the cavity can occur during laparotomy.

Granulomatous Necrotizing Myositis in Swine Affected by Porcine Circovirus Disease

Porcine circovirus type 2 (PCV2) is associated with multiple clinical syndromes in pigs, known as porcine circovirus diseases. This work describes an outbreak of porcine circovirus diseases with severe lesions affecting the skeletal muscle. Ninety-two pigs had apathy, weight loss, and diarrhea over a clinical course of 7 to 10 days. Approximately 30 of the pigs had stiff gait, muscle weakness, hind limb paresis, and recumbency. Twelve of the 92 pigs were necropsied, and 4 had pale discoloration of skeletal muscles with microscopic lesions of granulomatous necrotizing myositis. Immunohistochemistry of skeletal muscle showed that PCV2 antigen was located primarily in the cytoplasm and nuclei of macrophages, lymphocytes, and multinucleated giant cells, with a lower amount in the cytoplasm of endothelial cells, necrotic fibers, and satellite cells. Affected muscle samples were polymerase chain reaction–positive for PCV2 and the amplicon exhibited 99% identity with sequences belonging to the PCV2b genotype. Locomotor clinical signs and granulomatous necrotizing myositis should be considered as another expression of PCV2 infection in pigs.

GASTRIC PYTHIOSIS IN A BACTRIAN CAMEL (BACTRIANUS CAMELUS)

Abstract Pythium insidiosum, an aquatic oomycete, causes chronic lesions in the skin and digestive tract of multiple species. A captive-bred Bactrian camel (Camelus bactrianus) showed clinical signs of lethargy and weight loss in a clinical course of 30 days, with no response to treatment. At necropsy, the abdominal cavity had approximately 32 L of a yellow, turbid fluid with fibrin. The third compartment of the stomach (C-3) showed a focal area of rupture covered with fibrin. Close to this area, the C-3 wall was thickened and firm, demonstrating irregular, yellow, and friable areas on cut surface (kunkers). Microscopically, these corresponded to necrosis, characterized by a central amorphous eosinophilic material, surrounded by a pyogranulomatous inflammatory infiltrate and fibrosis. Negatively stained hyphae were observed at the periphery of the necrotic areas, which showed marked immunostaining for P. insidiosum. Pythiosis in camelids may involve the stomach, resulting in peritonitis and death.

Detection and phylogenetic characterization of porcine circovirus 2 from pigs in Mozambique

Porcine circovirus–associated diseases (PCVADs), caused by porcine circovirus 2 (PCV-2), have a significant economic impact on the swine industry worldwide. In Africa, there is little information, to date, regarding the occurrence of PCV-2, and it has not been reported in Mozambique’s swine population. We randomly collected mesenteric lymph nodes (n = 111) from slaughtered pigs from 9 districts in southern Mozambique. PCV-2 DNA was detected in 54% (62 of 111) of the samples and 78% (23 of 31) of the farms. PCV-2 antigen was detected by immunohistochemistry in lymph nodes (6 of 62; 10%) that were positive for PCV-2 by PCR. Histopathologic changes observed in these lymph nodes were lymphoid depletion, multifocal nodal necrosis, and infiltrates of histiocytes and multinucleate giant cells. One positive sample from each district was selected in order to obtain sequences covering the ORF2 region. Five sequences clustered with PCV-2d, of which 3 sequences from Maputo, Namaacha, and Moamba were grouped with PCV-2d-2; 2 sequences from Manhiça and Matola were grouped as PCV-2d-1; and 4 sequences from Boane, Matutuíne, Chibuto, and Xai-Xai were closely related to PCV-2b-1A/B genotypes. Our study indicates that a diversity of PCV-2 viruses is circulating in the Mozambican swine population.

Omphalitis, urachocystitis and septicemia by Streptococcus dysgalactiae in a Southern right whale calf (Eubalaena australis), Brazil

Southern right whales Eubalaena australis (SRW) use the southern coast of Brazil as a wintering and calving ground. Other than anthropogenic threats, there is limited knowledge on health and disease aspects for this species. We report the gross and microscopic findings and microbiological identification of streptococcal septicemia in a SRW calf. Main gross findings included fibrinosuppurative omphalitis and urachocystitis, suppurative cystitis, valvular endocarditis and myocarditis, embolic pneumonia, suppurative myositis and osteoarthritis, and lymphadenomegaly. Histological examination confirmed the above inflammatory processes and indicated disseminated Gram-positive coccoid septicemia. PCR analysis, based on the 16S rRNA gene from bacteria isolated on blood agar, identified Streptococcus dysgalactiae. Pathologic and microbiologic analysis indicated that β-hemolytic S. dysgalactiae septicemia, presumably initiated as ascending omphalic infection, was responsible for stranding and death in this individual. These results further confirm pathogenicity of streptococci in cetaceans and add to the limited health and disease related pathology knowledge for this species.