The assembly-defective phenotype of an FIV Gag polyprotein containing the SIV nucleocapsid zinc finger motifs is reversed by including the SIV SP2 domain in the chimeric protein.

To gain insight into the functional relationship between the nucleocapsid (NC) domains of the Gag polyproteins of feline and simian immunodeficiency viruses, FIV and SIV, respectively, we generated two FIV Gag chimeric proteins containing different SIV NC and gag sequences. A chimeric FIV Gag protein (NC1) containing the SIV two zinc fingers motifs was incapable of assembling into virus-like particles. By contrast, another Gag chimera (NC2) differing from NC1 by the replacement of the C-terminal region of the FIV NC with SIV SP2 produced particles as efficiently as wild-type FIV Gag. Of note, when the chimeric NC2 Gag polyprotein was expressed in the context of the proviral DNA in feline CrFK cells, wild-type levels of virions were produced which encapsidated 50% of genomic RNA when compared to the wild-type virus.

Use of selected samples to diagnose a tricky feline viral disease in a cat with uveitis and neurological signs.

This case involved a 2-year-old neutered male domestic mixed-breed cat that was rescued from the street eight months earlier. The animal presented with weakness, hyporexia, progressive weight loss, fatigue, uveitis, pale mucous membranes, dehydration (7%), and pelvic limb paresis. Aqueous humor was collected for molecular analysis for the differential diagnosis of potential etiological agents [Feline coronavirus (FCoV), Feline leukemia virus (FeLV), Feline immunodeficiency virus (FIV), Toxoplasma gondii, Cryptococcus spp., Felid herpesvirus-1 (FHV-1) and Bartonella spp.] of feline uveitis. The sample was positive by real-time reverse transcription-polymerase chain reaction (RT-qPCR) for FCoV and RT-qPCR and real-time polymerase chain reaction (qPCR) for FeLV and qPCR FIV. The cat was euthanized due to poor clinical outcomes and prognosis. A cerebrospinal fluid (CSF) sample was collected and tested, and the same pathogens were found in the aqueous humor. Small-cell follicular multicenter lymphoma and multifocal pyogranulomatous meningoencephalitis were observed upon histopathological analysis. In this study, aqueous humor and cerebrospinal fluid samples were efficient for the detection of coinfection with FIV, FeLV, and FCoV.

O caso refere-se a um gato de dois anos de idade, sem raça definida, resgatado da rua há oito meses. O animal apresentava fraqueza, hiporexia, emagrecimento progressivo, cansaço fácil, uveíte, mucosas pálidas, desidratação (7%) e paresia de membros pélvicos. O humor aquoso foi coletado para o diagnóstico molecular diferencial de potenciais agentes etiológicos [coronavírus felino (FCoV), vírus da leucemia felina (FeLV), vírus da imunodeficiência felina (FIV), Toxoplasma gondii, Cryptococcus spp., herpesvírus felino tipo 1 (FHV-1) and Bartonella spp.] causadores de uveíte felina. A amostra foi positiva na reação em cadeia da polimerase precedida por transcrição reversa em tempo real (RT-qPCR) para FCoV, RT-qPCR e reação em cadeia da polimerase em tempo real (qPCR) para FeLV e qPCR para FIV. O animal foi submetido à eutanásia - devido ao quadro clínico e prognóstico desfavorável. Amostra de líquido cefalorraquidiano (LCR) foi coletada e testada, confirmando a identificação dos mesmos patógenos encontrados no humor aquoso. Linfoma multicêntrico folicular de pequenas células e meningoencefalite piogranulomatosa multifocal foram observados na análise histopatológica. Neste relato, as amostras de humor aquoso e líquido cefalorraquidiano foram eficientes para a detecção de coinfecção por FIV, FeLV e FCoV.

Molecular detection of feline hemoplasmas and retroviruses in free-roaming and shelter cats within a university campus.

Objectives: The aim of the present study was to assess the frequency of hemoplasma, feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) infections in cats living in an on-campus shelter and free-roaming cats within a university campus in Brazil. Methods: Blood samples were tested using quantitative PCR for hemoplasma, FIV and FeLV. Positive hemoplasma samples were sequenced. Associations between hemoplasma detection and living situation, sex, flea and/or tick parasitism, and coinfection with FIV and FeLV, were assessed using Fisher's exact test and the respective odds ratios were calculated. Results: Overall, 6/45 (13.3%) cats tested positive: four (8.9%) were infected with 'Candidatus Mycoplasma haemominutum' and two (4.4%) with Mycoplasma haemofelis. All positive samples were from free-roaming cats (6/15; 40.0%) and had statistically significantly lower packed cell volumes (P = 0.037). Although 5/23 (21.7%) males and 1/22 (4.6%) females were positive, no statistically significant association between sex and hemoplasma infection was found (P = 0.19). Viral quantitative PCR (qPCR) was performed on 43/45 samples, among which 2/43 (4.7%) were positive for FIV and none for FeLV. Only one cat (2.3%) was coinfected with hemoplasma and FIV (P = 0.26). In addition, 4/6 (66.7%) cats that tested positive for hemoplasmas were infested by fleas (P = 0.0014) and/or ticks (P = 0.25). Conclusions and relevance: These results show that even if the free-roaming cat population is clinically healthy and has adequate access to food, it may present flea infestation and hemoplasma infection with lower packed cell volume values.

Domestic Cat Hepadnavirus and Pathogenic Retroviruses; A Sero-Molecular Survey of Cats in Santiago, Chile.

Cat ownership is common in Chile, but data on the regional prevalence of infectious agents are limited. A sero-molecular survey of 120 client- or shelter-owned domestic cats in greater Santiago was performed. Whole blood DNA was tested for the novel hepatitis-B-like virus, domestic cat hepadnavirus (DCH) by conventional PCR (cPCR) and quantitative PCR (qPCR), and for feline leukaemia virus (FeLV) by qPCR. Point-of-care serology for FeLV p27 antigen and antibodies recognising feline immunodeficiency virus (FIV) p15 and p24 was performed. DCH DNA was detected in the serum of 2/120 cats (1.67%). Sequencing and phylogenetic analysis showed that the DCH detected in Chile occupies a position outside the main clustering of DCH in the near-complete genome tree. Progressive (antigen-positive, provirus-positive) and regressive (antigen-negative, provirus-positive) FeLV infections were identified in 6/120 (5%) and 9/120 (7.5%) of cats. A total of 2/120 (1.7%) cats had dual FeLV/FIV infection, and another 2 cats had FIV infection alone. This study shows that the global footprint of DCH includes South America with a low molecular frequency in Chile, similar to that reported in the USA. Progressive FeLV infection is relatively common in urban Chile, and male cats are at greater risk than females. Testing and control measures for pathogenic retroviruses are indicated. The potential impact of FeLV, FIV and DCH on Chile's wildcat species is worthy of further investigation.

Developing a Feline Immunodeficiency Virus Subtype B Vaccine Prototype Using a Recombinant MVA Vector.

The feline immunodeficiency virus (FIV) is a retrovirus with global impact and distribution, affecting both domestic and wild cats. This virus can cause severe and progressive immunosuppression culminating in the death of felids. Since the discovery of FIV, only one vaccine has been commercially available. This vaccine has proven efficiency against FIV subtypes A and D, whereas subtype B (FIV-B), found in multiple continents, is not currently preventable by vaccination. We, therefore, developed and evaluated a vaccine prototype against FIV-B using the recombinant viral vector modified vaccinia virus Ankara (MVA) expressing the variable region V1-V3 of the FIV-B envelope protein. We conducted preclinical tests in immunized mice (C57BL/6) using a prime-boost protocol with a 21 day interval and evaluated cellular and humoral responses as well the vaccine viability after lyophilization and storage. The animals immunized with the recombinant MVA/FIV virus developed specific splenocyte proliferation when stimulated with designed peptides. We also detected cellular and humoral immunity activation with IFN-y and antibody production. The data obtained in this study support further development of this immunogen and testing in cats.

Feline Heartworm in Clinical Settings in a High Canine Prevalence Area.

Heartworm (HTW) infection in cats is associated with persistent pulmonary pathology, even when clinical signs are absent. Treatment options for cats are limited once infected, making prevention an important topic for discussion with cat owners. In Brazil, tests to detect feline HTW infections are unavailable, likely leading to an underestimation of its impact on the wellbeing of cats. The present study investigated the seroprevalence of HTW antigen in cats living in an area with high canine HTW prevalence and investigated risk factors and clinical signs associated with HTW disease in cats from Rio de Janeiro, Brazil. Clinical examinations were conducted, and serological evaluations performed with a point-of-care test (SNAP® Feline Triple® Test, IDEXX Laboratories, Inc.). A total of 586 cats were examined. The HTW antigen seroprevalence was 1.2%. Heartworm positive results were significantly associated with vomiting and abnormal lung sounds. Results from this study indicate that cats residing in areas of high canine HTW prevalence should have HTW disease as a differential diagnosis when presenting with compatible clinical signs. Veterinarians should prioritize client education and promote regular use of effective prophylaxis to protect feline health.

The outcomes of polyparasitism in stray cats from Brazilian Midwest assessed by epidemiological, hematological and pathological data / Poliparasitismo em gatos não domiciliados no Centro-Oeste brasileiro avaliado através dos aspectos epidemiológicos, hematológicos e patológicos

We evaluated the epidemiological, hematological, and pathological data of Leishmania spp., Toxoplasma gondii, Platynosomum illiciens, feline immunodeficiency virus (FIV), and feline leukemia virus (FeLV) infections and the coinfections in stray cats of an endemic area for leishmaniasis. The diagnosis was performed by serological tests and necropsy. We described gross lesions and histopathological findings. We used immunohistochemistry and chromogenic in situ hybridization for L. infantum detection. We found infection in 27 out of 50 sampled cats, among them, 14 presented coinfections. A strong correlation between splenomegaly and lymphadenomegaly with FeLV, and an association between hepatic lesions and cachexia with parasitism due to P. illiciens were observed. Moreover, we found a significant increase in the monocyte count in the FeLV-infected and a decrease in the red blood cell count in the FIV-infected animals. Amastigote forms of Leishmania spp. and tissue changes were detected in lymphoid organs of an animal coinfected with P. illiciens, T. gondii, and FIV. Polyparasitism recorded in stray cats of the Brazilian Midwest should be considered in effective control strategies for public health diseases. Moreover, stray cats of Campo Grande may be a source of infection of FIV, FeLV and P. illiciens for populations of domiciled cats.(AU)

Foi avaliada a epidemiologia, hematologia e patologia das infecções por Leishmania spp., Toxoplasma gondii, Platynosomum illiciens, vírus da imunodeficiência felina (FIV) e vírus da leucemia felina (FeLV) e das coinfecções em gatos não domiciliados em uma área endêmica para leishmaniose. O diagnóstico foi realizado por exames sorológicos e necropsia. Foram descritas lesões macroscópicas e achados histopatológicos. Usaram-se imuno-histoquímica e hibridização cromogênica in situ para detecção de L. infantum. Encontrou-se infecção em 27 dos 50 gatos amostrados, dentre eles, 14 apresentavam coinfecções. Foi observada forte correlação entre esplenomegalia e linfadenomegalia com FeLV, e associação entre lesões hepáticas e caquexia com parasitismo por P. illiciens. Além disso, foi encontrado um aumento significativo na contagem de monócitos nos animais infectados pelo FeLV e uma diminuição na contagem de hemácias nos animais infectados pelo FIV. Formas amastigotas de Leishmania spp. e alterações teciduais foram detectadas em órgãos linfoides de um animal coinfectado com P. illiciens, T. gondii e FIV. O poliparasitismo registrado em gatos errantes do Centro-Oeste brasileiro deve ser considerado nas estratégias de controle de zoonoses. Além disso, gatos errantes de Campo Grande podem ser fontes de infecção de FIV, FeLV e P. illiciens para populações de gatos domiciliados.(AU)

Prevalence of Feline Immunodeficiency Virus and Toxoplasma gondii in Feral Cats on St. Kitts, West Indies.

Toxoplasma gondii (T. gondii) is a cosmopolitan protozoan parasite that infects all warm-blooded species including humans. The definitive hosts of T. gondii are felid vertebrates including the domestic cat. Domestic cats shed oocysts for approximately two weeks in their feces after the primary infection. It has been shown that feline immunodeficiency virus (FIV) positive cats have a higher prevalence of and a higher titer of antibodies to T. gondii than those of FIV-negative cats. The main purposes of this study were to determine FIV prevalence and to investigate the oocysts shedding in FIV-positive and FIV-negative feral cats on St. Kitts. Fecal samples were collected from feral cats while their FIV statues were determined using a commercial SNAP kit. Total fecal DNA of each cat was tested for the presence of T. gondii DNA using a polymerase chain reaction (PCR) consistently detecting one genome equivalent. A FIV-positive status was detected in 18 of 105 (17.1%, 95% confidence interval (CI): 9.9%-24.3%) feral cats sampled. Furthermore, males were three times more likely to be FIV positive than females (p = 0.017) with an odds ratio of 3.93 (95% CI: 1.20-12.89). Adults were found to have at least twice the prevalence of FIV compared to cats younger than one year of age (p = 0.056) with an odds ratio of 3.07 (95% CI: 0.94-10.00). Toxoplasma gondii DNA was not detected in the feces of any of the 18 FIV-positive (95% CI: 0%-0.18%) and 87 FIV-negative cats (95% CI: 0%-0.04%). A follow-up study with a much bigger sample size is needed to prove or disprove the hypothesis that FIV-positive cats have a higher prevalence of shedding T. gondii oocysts than FIV-negative cats.

Estandarización de PCR múltiple en tiempo real para el diagnóstico de sida y leucemia en Felis silvestris catus / Standardization of Multiplex Real-Time PCR for the diagnosis of Feline Immunodeficiency Virus (FIV) and Feline Leukemia Virus (FeLV) in Felis silvestris catus / Padronização da PCR múltipla em tempo real para o diagnóstico de AIDS e leucemia em Felis silvestris catus

Resumen Las enfermedades producidas por virus como sida y leucemia son altamente prevalentes en felinos domésticos, debido a su facilidad de transmisión, presentan signos clínicos similares a otras infecciones que pueden generar dificultades en el diagnóstico, por lo tanto, se deben analizar mediante pruebas de laboratorio; los exámenes disponibles en la actualidad presentan algunas desventajas, por ello se estandarizó una PCR múltiple en tiempo real con sondas Taqman que fue diseñada para detección de infección con el virus de inmunodeficiencia felina (VIF), el virus de leucemia felina (VLFe) o mixtas. Se calculó la sensibilidad (0,53/0,26) y la especificidad (0,46/0,74) para leucemia y sida respectivamente con la metodología de Broemeling que considera que la prueba de referencia contra la cual se compara no es un referente verdadero (Gold standard), según estos resultados se concluye que es necesario aumentar el tamaño de muestra; sin embargo, la PCR múltiple es una metodología muy sensible, fue validada de forma In silico y presentó resultados congruentes al realizarla in vivo.

Abstract Diseases such as Feline Immunodeficiency Virus (VIF) and Feline Leukemia Virus (VLFe) are highly prevalent in domestic cats, due to their ease of transmission. Clinical signs are similar to other infections causing difficulties in diagnosis, therefore, they should be analyzed by laboratory tests; Currently available tests have some disadvantages, a multiplex real-time PCR was standardized with Taqman probes, designed for detection of infection with VIF, VLFe or both. Sensitivity (0.53/0.26) and specificity (0.46/0.74) for VLFe and VIF respectively, were calculated with Broemeling's methodology, which considers that the reference test against which it is compared is not a Gold standard, according to these results it is necessary to increase the sample size; However, multiplex PCR is a very sensitive methodology, it was validated In silico form and presented congruent results when performed in vivo.

Resumo Doenças causadas por vírus como AIDS e leucemia são altamente prevalentes em gatos domésticos, devido a sua facilidade de transmissão com sinais clínicos semelhantes a outras infecções que podem causar dificuldades no diagnóstico, portanto devem ser analisados ​​por exames laboratoriais; Os testes atualmente disponíveis têm algumas desvantagens, portanto uma PCR em tempo real múltipla foi padronizada com sondas Taqman para a detecção de infecção pelo vírus da imunodeficiência felina (FIV), vírus da leucemia felina (VLFe) ou misto . A sensibilidade (0,53 /0,26) e a especificidade (0,46/0,74) para leucemia e AIDS foram calculadas, respectivamente, com a metodologia de Broemeling, que considera que o teste de referência com o qual é comparado não é um referência verdadeira (teste de ouro), de acordo com esses resultados, conclui-se que é necessário aumentar o tamanho da amostra, entretanto, a PCR múltipla é uma metodologia muito sensível, foi validada na forma silico e apresentou resultados congruentes quando realizada in vivo.

Alterações laboratoriais e post-mortem de um felino com doença renal crônica positivo para o vírus da imunodeficiência felina / Laboratory changes and post-death of a feline with positive chronic kidney disease for the feline immunodeficiency virus

A Imunodeficiência Viral Felina (FIV) é uma patologia infecciosa, na qual o vírus está presente na saliva de gatos infectados, o que mostra transmissão direta por ferimentos causados por mordidas, além disso, pode ocorrer transmissão vertical. A doença renal crônica (DRC)é uma das patologias mais comumente observadas em gatos infectados com FIV. O objetivo do trabalho foi descrever um relato de caso clínico de um felino com DRC portador do FIV, enfatizando suas alterações laboratoriais e post-mortem. Foi atendido no Hospital Veterinário Adrisse, Fortaleza-CE, um felino, sem raça definida, de aproximadamente sete anos. Segundo a tutora, o felino havia fugido de casa, e quando retornou, apresentava vômitos esporádicos, diarreia e anorexia há quatro dias. No exame físico, apresentava quadro de ataxia, apatia, grau de desidratação em torno de 8%, dor abdominal, mioclonias, êmese, hipotermia, nistagmo bilateral, mucosas levemente ictéricas, desnutrição, urina concentrada, úlceras na boca e hálito urêmico. Foram solicitados como exames complementares: hemograma e dosagens bioquímicas (alanina aminotransferase, creatinina, aspartatoaminotransferase), sódio, potássio, fósforo, fosfatase alcalina, cálcio, ureia, sumário de urina, ultrassonografia abdominal e snap® teste FIV/FeLV. O diagnóstico foi conclusivo através do snap FIV/FelV e a DRC se confirmou pela ultrassonografia abdominal e necropsia, através de alterações compatíveis com os sintomas e achados laboratoriais. Pode-se concluir que em felinos acometidos por FIV, são imprescindíveis a avaliação clínica e o diagnóstico de complicações renais, visto que há uma ação viral no desencadeamento de lesões renais, os quais podem ser identificados por meio de exames laboratoriais, ultrassonográficos e necroscópicos.(AU)

Feline Viral Immunodeficiency (FIV) is an infectious pathology, in which the virus is present in the saliva of infected cats, which shows direct transmission through injuries caused by bites, in addition, vertical transmission can occur. Chronic kidney disease (CKD) is one of the pathologies most commonly seen in cats infected with IVF. The objective of the study was to describe a clinical case report of a feline with CKD with IVF, emphasizing his laboratory and post-mortem changes. At the Veterinary Hospital Adrisse, Fortaleza-CE, a feline, of mixed breed, of approximately seven years was attended. According to the tutor, the cat had run away from home, and when he returned, he had sporadic vomiting, diarrhea and anorexia for four days. On physical examination, he presented ataxia, apathy, degree of dehydration around 8%, abdominal pain, myoclonus, emesis, hypothermia, bilateral nystagmus, slightly jaundiced mucous membranes, malnutrition, concentrated urine, mouth ulcers and uremic breath. Complementary tests were requested: blood count and biochemical measurements (alanine aminotransferase, creatinine, aspartate aminotransferase), sodium, potassium, phosphorus, alkaline phosphatase, calcium, urea, urine summary, abdominal ultrasound and snap® FIV/FeLV test. The diagnosis was conclusive through the FIV/FelV snap and CKD was confirmed by abdominal ultrasound and necropsy, through alterations compatible with the symptoms and laboratory findings. It can be concluded that in cats affected by FIV, clinical evaluation and diagnosis of kidney complications are essential, since there is a viral action in the triggering of kidney injuries, which can be identified through laboratory, ultrasound and necroscopic exams.(AU)

Alterações laboratoriais e post-mortem de um felino com doença renal crônica positivo para o vírus da imunodeficiência felina / Laboratory changes and post-death of a feline with positive chronic kidney disease for the feline immunodeficiency virus

A Imunodeficiência Viral Felina (FIV) é uma patologia infecciosa, na qual o vírus está presente na saliva de gatos infectados, o que mostra transmissão direta por ferimentos causados por mordidas, além disso, pode ocorrer transmissão vertical. A doença renal crônica (DRC)é uma das patologias mais comumente observadas em gatos infectados com FIV. O objetivo do trabalho foi descrever um relato de caso clínico de um felino com DRC portador do FIV, enfatizando suas alterações laboratoriais e post-mortem. Foi atendido no Hospital Veterinário Adrisse, Fortaleza-CE, um felino, sem raça definida, de aproximadamente sete anos. Segundo a tutora, o felino havia fugido de casa, e quando retornou, apresentava vômitos esporádicos, diarreia e anorexia há quatro dias. No exame físico, apresentava quadro de ataxia, apatia, grau de desidratação em torno de 8%, dor abdominal, mioclonias, êmese, hipotermia, nistagmo bilateral, mucosas levemente ictéricas, desnutrição, urina concentrada, úlceras na boca e hálito urêmico. Foram solicitados como exames complementares: hemograma e dosagens bioquímicas (alanina aminotransferase, creatinina, aspartatoaminotransferase), sódio, potássio, fósforo, fosfatase alcalina, cálcio, ureia, sumário de urina, ultrassonografia abdominal e snap® teste FIV/FeLV. O diagnóstico foi conclusivo através do snap FIV/FelV e a DRC se confirmou pela ultrassonografia abdominal e necropsia, através de alterações compatíveis com os sintomas e achados laboratoriais. Pode-se concluir que em felinos acometidos por FIV, são imprescindíveis a avaliação clínica e o diagnóstico de complicações renais, visto que há uma ação viral no desencadeamento de lesões renais, os quais podem ser identificados por meio de exames laboratoriais, ultrassonográficos e necroscópicos.

Feline Viral Immunodeficiency (FIV) is an infectious pathology, in which the virus is present in the saliva of infected cats, which shows direct transmission through injuries caused by bites, in addition, vertical transmission can occur. Chronic kidney disease (CKD) is one of the pathologies most commonly seen in cats infected with IVF. The objective of the study was to describe a clinical case report of a feline with CKD with IVF, emphasizing his laboratory and post-mortem changes. At the Veterinary Hospital Adrisse, Fortaleza-CE, a feline, of mixed breed, of approximately seven years was attended. According to the tutor, the cat had run away from home, and when he returned, he had sporadic vomiting, diarrhea and anorexia for four days. On physical examination, he presented ataxia, apathy, degree of dehydration around 8%, abdominal pain, myoclonus, emesis, hypothermia, bilateral nystagmus, slightly jaundiced mucous membranes, malnutrition, concentrated urine, mouth ulcers and uremic breath. Complementary tests were requested: blood count and biochemical measurements (alanine aminotransferase, creatinine, aspartate aminotransferase), sodium, potassium, phosphorus, alkaline phosphatase, calcium, urea, urine summary, abdominal ultrasound and snap® FIV/FeLV test. The diagnosis was conclusive through the FIV/FelV snap and CKD was confirmed by abdominal ultrasound and necropsy, through alterations compatible with the symptoms and laboratory findings. It can be concluded that in cats affected by FIV, clinical evaluation and diagnosis of kidney complications are essential, since there is a viral action in the triggering of kidney injuries, which can be identified through laboratory, ultrasound and necroscopic exams.

The Conserved Tyr176/Leu177 Motif in the α-Helix 9 of the Feline Immunodeficiency Virus Capsid Protein Is Critical for Gag Particle Assembly.

The capsid domain (CA) of the lentiviral Gag polyproteins has two distinct roles during virion morphogenesis. As a domain of Gag, it mediates the Gag-Gag interactions that drive immature particle assembly, whereas as a mature protein, it self-assembles into the conical core of the mature virion. Lentiviral CA proteins are composed of an N-terminal region with seven α-helices and a C-terminal domain (CA-CTD) formed by four α-helices. Structural studies performed in HIV-1 indicate that the CA-CTD helix 9 establishes homodimeric interactions that contribute to the formation of the hexameric Gag lattice in immature virions. Interestingly, the mature CA core also shows inter-hexameric associations involving helix 9 residues W184 and M185. The CA proteins of feline immunodeficiency virus (FIV) and equine infectious anemia virus (EIAV) exhibit, at equivalent positions in helix 9, the motifs Y176/L177 and L169/F170, respectively. In this paper, we investigated the relevance of the Y176/L177 motif for FIV assembly by introducing a series of amino acid substitutions into this sequence and studying their effect on in vivo and in vitro Gag assembly, CA oligomerization, mature virion production, and viral infectivity. Our results demonstrate that the Y176/L177 motif in FIV CA helix 9 is essential for Gag assembly and CA oligomerization. Notably, mutations converting the FIV CA Y176/L177 motif into the HIV-1 WM and EIAV FL sequences allow substantial particle production and viral replication in feline cells.

Feline Leukaemia Virus Associated with Leukaemia in Cats in Santa Catarina, Brazil.

Leukaemia is a haemopoietic neoplasm originating from myeloid or lymphoid precursors in the bone marrow and may be either acute or chronic. These tumours are rare, but occur more frequently in cats because of an association with the feline leukaemia virus (FeLV) and feline immunodeficiency virus (FIV). To the best of our knowledge, no studies conducted in Brazil to date have analysed the association between leukaemia and FeLV and FIV infection in cats. The aim of this study was to perform a histopathological analysis of feline leukaemia and evaluate the association between leukaemia and FeLV and FIV infection in cats. The study evaluated 37 cats with leukaemia diagnosed between 2009 and 2017. The animals underwent necropsy examination, histopathology and immunohistochemistry with anti-FeLV gp70 and anti-FIV p24 gag antibodies. Of the evaluated animals, 54% (20/37) were males and 43.2% (16/37) were females. With respect to the life stage of the animals, 24.3% (9/37) were junior, 32.4% (12/37) were prime, 18.9% (7/37) were mature and 10.8% (4/37) were senior, and five animals were of unknown age. Myeloid leukaemia occurred in 56.8% (21/37) of the cases and lymphocytic leukaemia occurred in 43.2% (16/37) of the cases. Acute leukaemia (73%, 27/37) was more common than chronic leukaemia (27%, 10/37). The positivity for FeLV (78.4%, 29/37) and FIV (16.2%, 6/37) indicated a high association between FeLV infection and tumour development in the study region.

Feline immunodeficiency virus in Northern Ceará, Brazil.

OBJECTIVES: The objectives of this study were to confirm the prevalence of feline immunodeficiency virus (FIV) infection in domestic cats in the region north of Ceará, Brazil, and to determine the factors associated with infection and the major circulating subtypes of the virus in this area. METHODS: Samples from 148 cats were collected and tested using anti-FIV antibody screening, with confirmation of positive results by PCR. Univariate analysis was performed considering the epidemiological characteristics and FIV status. Sequencing and phylogenetic analysis of the gag and pol genes were performed to confirm the FIV subtype. RESULTS: Nine cats (6.1%) tested positive for FIV - one female (0.7%) and eight males (5.4%). Male cats were significantly more likely to be infected (P <0.05). Phylogenetic analysis of gag and pol gene sequences indicated that the FIV isolates circulating in the study area belonged to subtype B. CONCLUSIONS AND RELEVANCE: In this study, we demonstrated a low prevalence for FIV in the northwest of Ceará, north-eastern Brazil. Male sex is a significant risk factor for FIV infection and the best predictive factor for FIV status. All isolates examined in this study clustered within subtype B, which is the predominant subtype in Brazil. This is the first report of genetic characterization of FIV in the state of Ceará, Brazil.

Properties and Functions of Feline Immunodeficiency Virus Gag Domains in Virion Assembly and Budding.

Feline immunodeficiency virus (FIV) is an important cat pathogen worldwide whose biological and pathophysiological properties resemble those of human immunodeficiency virus type 1 (HIV-1). Therefore, the study of FIV not only benefits its natural host but is also useful for the development of antiviral strategies directed against HIV-1 infections in humans. FIV assembly results from the multimerization of a single but complex viral polypeptide, the Gag precursor. In this review, we will first give an overview of the current knowledge of the proteins encoded by the FIV pol, env, rev, vif, and orf-A genes, and then we will describe and discuss in detail the critical roles that each of the FIV Gag domains plays in virion morphogenesis. Since retroviral assembly is an attractive target for therapeutic interventions, gaining a better understanding of this process is highly desirable.

Aspectos anatomopatológicos e avaliação de agentes infecciosos em 32 gatos com colângio-hepatite / Anatomopathological aspects and determination of infectious agents in 32 cats with cholangiohepatitis

A colângio-hepatite é considerada uma causa frequente de insuficiência hepática em gatos e é classificada em neutrofílica, linfocítica e esclerosante. Os objetivos deste estudo foram determinar a frequência de colângio-hepatite em gatos diagnosticados na Região Metropolitana de Porto Alegre, descrever seus aspectos anatomopatológicos e estabelecer uma associação com as infecções por Escherichia coli, vírus da imunodeficiência felina (FIV) e vírus da leucemia felina (FeLV). No período de janeiro de 2000 a julho de 2016 o Setor de Patologia Veterinária da Universidade Federal do Rio Grande do Sul realizou 1915 necropsias de gatos, destes, 32 foram diagnosticados com colângio-hepatite, representando 1,7% dos casos. Destes, a colângio-hepatite linfocítica (CHL) foi diagnosticada em 68,7% (22/32), a neutrofílica (CHN) em 21,9% (7/32) e a esclerosante (CHE) com 9,4% (3/32). A idade variou de quatro meses a 16 anos, com a mediana de seis anos, acometendo predominantemente gatos sem raça definida. Somente na CHN observou-se predisposição por machos, verificado em 85,7% (6/7) dos casos. Enterite e pancreatite foram identificadas concomitantemente com a colângio-hepatite em 56,2% (18/32) dos casos, cada, e a formação de tríade foi identificada em 46,9% (15/32) dos gatos. Através da imuno-histoquímica, 68,2% (15/22) dos gatos com CHL, foram positivos para FIV, 40,9% (9/22) para FeLV e 31,8% (7/22) marcação para ambos os retrovírus. Na CHN, 85,7% (6/7) positivos para FIV, 57,1% (4/7) para FeLV e 42,8% (3/7) imunorreação para os dois retrovírus. Na CHE, 100% (3/3) dos casos apresentaram marcação para FeLV, 33,3% (1/3) para FIV e 33,3% (1/3) para ambos. Imunomarcação para E. coli foi observada em 27,3% (6/22) dos casos da CHL, 28,6% (2/7) da CHN e em 33,3% (1/3) da CHE. E. coli, Enterococcus sp. e Klebsiella pneumoniae foram os micro-organismos mais frequentes isolados no exame bacteriológico...(AU)

Cholangiohepatitis is considered a frequent cause of liver failure in cats, and are classified as neutrophilic, lymphocytic and sclerosing. The aims of this study was to determine the frequency of cholangiohepatitis in cats diagnosed in the metropolitan region of Porto Alegre, to describe the anatomopathological aspects and to establish an association with Escherichia coli, feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV). From January 2000 to July 2016, the Department of Veterinary Pathology of the Universidade Federal do Rio Grande do Sul performed 1915 cat necropsies, of which 32 were diagnosed with cholangiohepatitis, representing 1.7% of the cases. Of these, lymphocytic cholangiohepatitis (LCH) was diagnosed in 68.7% (22/32), neutrophilic (NCH) in 21.9% (7/v) and sclerosing cholangiohepatitis (SCH) with 9.4% (3/32) of the cases. In general, age ranged from four months to 16 years, with the median age of six years, and predominantly affected cats with mixed breed. Only in NCH demonstrated male predisposition, verified in 85.7% (6/7) of this cases. Enteritis and pancreatitis were identified concomitantly with cholangiohepatitis in 56.2% (18/32) cases, each, and triad formation was identified in 46.9% (15/32) of cats. In the immunohistochemistry, we observed that 68.2% (15/22) of the cats with LCH were positive for FIV, 40.9% (9/22) for FeLV, and 31.8% (7/22) positive for both retroviruses. In NCH, 85.7% (6/7) was positive for FIV, 57.1% (4/7) for FeLV, and 42.8% (3/7) immunoreactions for the two retroviruses. In SCH, 100% (3/3) of the cases presented FeLV marking, 33.3% (1/3) for FIV and 33.3% (1/3) for both. Immunostaining for E. coli was observed in 27.3% (6/22) of LCH, 28.6% (2/7) of NCH, and 33.3% (1/3) of SCH. E. coli, Enterococcus sp. and Klebsiella pneumoniae were the most frequently microorganisms isolated in the bacteriological examination. The visualization of E. coli by the immunohistochemistry in the hepatobiliary system...(AU)

Aspectos anatomopatológicos e avaliação de agentes infecciosos em 32 gatos com colângio-hepatite / Anatomopathological aspects and determination of infectious agents in 32 cats with cholangiohepatitis

A colângio-hepatite é considerada uma causa frequente de insuficiência hepática em gatos e é classificada em neutrofílica, linfocítica e esclerosante. Os objetivos deste estudo foram determinar a frequência de colângio-hepatite em gatos diagnosticados na Região Metropolitana de Porto Alegre, descrever seus aspectos anatomopatológicos e estabelecer uma associação com as infecções por Escherichia coli, vírus da imunodeficiência felina (FIV) e vírus da leucemia felina (FeLV). No período de janeiro de 2000 a julho de 2016 o Setor de Patologia Veterinária da Universidade Federal do Rio Grande do Sul realizou 1915 necropsias de gatos, destes, 32 foram diagnosticados com colângio-hepatite, representando 1,7% dos casos. Destes, a colângio-hepatite linfocítica (CHL) foi diagnosticada em 68,7% (22/32), a neutrofílica (CHN) em 21,9% (7/32) e a esclerosante (CHE) com 9,4% (3/32). A idade variou de quatro meses a 16 anos, com a mediana de seis anos, acometendo predominantemente gatos sem raça definida. Somente na CHN observou-se predisposição por machos, verificado em 85,7% (6/7) dos casos. Enterite e pancreatite foram identificadas concomitantemente com a colângio-hepatite em 56,2% (18/32) dos casos, cada, e a formação de tríade foi identificada em 46,9% (15/32) dos gatos. Através da imuno-histoquímica, 68,2% (15/22) dos gatos com CHL, foram positivos para FIV, 40,9% (9/22) para FeLV e 31,8% (7/22) marcação para ambos os retrovírus. Na CHN, 85,7% (6/7) positivos para FIV, 57,1% (4/7) para FeLV e 42,8% (3/7) imunorreação para os dois retrovírus. Na CHE, 100% (3/3) dos casos apresentaram marcação para FeLV, 33,3% (1/3) para FIV e 33,3% (1/3) para ambos. Imunomarcação para E. coli foi observada em 27,3% (6/22) dos casos da CHL, 28,6% (2/7) da CHN e em 33,3% (1/3) da CHE. E. coli, Enterococcus sp. e Klebsiella pneumoniae foram os micro-organismos mais frequentes isolados no exame bacteriológico. A visualização da E. coli, através da IHQ no sistema hepatobiliar de gatos diagnosticados com colângio-hepatite associados à inflamação, sugere que a doença se desenvolveu secundariamente à infecção bacteriana ascendente.(AU)

Cholangiohepatitis is considered a frequent cause of liver failure in cats, and are classified as neutrophilic, lymphocytic and sclerosing. The aims of this study was to determine the frequency of cholangiohepatitis in cats diagnosed in the metropolitan region of Porto Alegre, to describe the anatomopathological aspects and to establish an association with Escherichia coli, feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV). From January 2000 to July 2016, the Department of Veterinary Pathology of the Universidade Federal do Rio Grande do Sul performed 1915 cat necropsies, of which 32 were diagnosed with cholangiohepatitis, representing 1.7% of the cases. Of these, lymphocytic cholangiohepatitis (LCH) was diagnosed in 68.7% (22/32), neutrophilic (NCH) in 21.9% (7/v) and sclerosing cholangiohepatitis (SCH) with 9.4% (3/32) of the cases. In general, age ranged from four months to 16 years, with the median age of six years, and predominantly affected cats with mixed breed. Only in NCH demonstrated male predisposition, verified in 85.7% (6/7) of this cases. Enteritis and pancreatitis were identified concomitantly with cholangiohepatitis in 56.2% (18/32) cases, each, and triad formation was identified in 46.9% (15/32) of cats. In the immunohistochemistry, we observed that 68.2% (15/22) of the cats with LCH were positive for FIV, 40.9% (9/22) for FeLV, and 31.8% (7/22) positive for both retroviruses. In NCH, 85.7% (6/7) was positive for FIV, 57.1% (4/7) for FeLV, and 42.8% (3/7) immunoreactions for the two retroviruses. In SCH, 100% (3/3) of the cases presented FeLV marking, 33.3% (1/3) for FIV and 33.3% (1/3) for both. Immunostaining for E. coli was observed in 27.3% (6/22) of LCH, 28.6% (2/7) of NCH, and 33.3% (1/3) of SCH. E. coli, Enterococcus sp. and Klebsiella pneumoniae were the most frequently microorganisms isolated in the bacteriological examination. The visualization of E. coli by the immunohistochemistry in the hepatobiliary system of cats diagnosed with cholangiohepatitis suggests that the disease developed secondary to ascending bacterial infection.(AU)

Aspectos anatomopatológicos e avaliação de agentes infecciosos em 32 gatos com colângio-hepatite

ABSTRACT: Cholangiohepatitis is considered a frequent cause of liver failure in cats, and are classified as neutrophilic, lymphocytic and sclerosing. The aims of this study was to determine the frequency of cholangiohepatitis in cats diagnosed in the metropolitan region of Porto Alegre, to describe the anatomopathological aspects and to establish an association with Escherichia coli, feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV). From January 2000 to July 2016, the Department of Veterinary Pathology of the Universidade Federal do Rio Grande do Sul performed 1915 cat necropsies, of which 32 were diagnosed with cholangiohepatitis, representing 1.7% of the cases. Of these, lymphocytic cholangiohepatitis (LCH) was diagnosed in 68.7% (22/32), neutrophilic (NCH) in 21.9% (7/v) and sclerosing cholangiohepatitis (SCH) with 9.4% (3/32) of the cases. In general, age ranged from four months to 16 years, with the median age of six years, and predominantly affected cats with mixed breed. Only in NCH demonstrated male predisposition, verified in 85.7% (6/7) of this cases. Enteritis and pancreatitis were identified concomitantly with cholangiohepatitis in 56.2% (18/32) cases, each, and triad formation was identified in 46.9% (15/32) of cats. In the immunohistochemistry, we observed that 68.2% (15/22) of the cats with LCH were positive for FIV, 40.9% (9/22) for FeLV, and 31.8% (7/22) positive for both retroviruses. In NCH, 85.7% (6/7) was positive for FIV, 57.1% (4/7) for FeLV, and 42.8% (3/7) immunoreactions for the two retroviruses. In SCH, 100% (3/3) of the cases presented FeLV marking, 33.3% (1/3) for FIV and 33.3% (1/3) for both. Immunostaining for E. coli was observed in 27.3% (6/22) of LCH, 28.6% (2/7) of NCH, and 33.3% (1/3) of SCH. E. coli, Enterococcus sp. and Klebsiella pneumoniae were the most frequently microorganisms isolated in the bacteriological examination. The visualization of E. coli by the immunohistochemistry in the hepatobiliary system of cats diagnosed with cholangiohepatitis suggests that the disease developed secondary to ascending bacterial infection.

RESUMO: A colângio-hepatite é considerada uma causa frequente de insuficiência hepática em gatos e é classificada em neutrofílica, linfocítica e esclerosante. Os objetivos deste estudo foram determinar a frequência de colângio-hepatite em gatos diagnosticados na Região Metropolitana de Porto Alegre, descrever seus aspectos anatomopatológicos e estabelecer uma associação com as infecções por Escherichia coli, vírus da imunodeficiência felina (FIV) e vírus da leucemia felina (FeLV). No período de janeiro de 2000 a julho de 2016 o Setor de Patologia Veterinária da Universidade Federal do Rio Grande do Sul realizou 1915 necropsias de gatos, destes, 32 foram diagnosticados com colângio-hepatite, representando 1,7% dos casos. Destes, a colângio-hepatite linfocítica (CHL) foi diagnosticada em 68,7% (22/32), a neutrofílica (CHN) em 21,9% (7/32) e a esclerosante (CHE) com 9,4% (3/32). A idade variou de quatro meses a 16 anos, com a mediana de seis anos, acometendo predominantemente gatos sem raça definida. Somente na CHN observou-se predisposição por machos, verificado em 85,7% (6/7) dos casos. Enterite e pancreatite foram identificadas concomitantemente com a colângio-hepatite em 56,2% (18/32) dos casos, cada, e a formação de tríade foi identificada em 46,9% (15/32) dos gatos. Através da imuno-histoquímica, 68,2% (15/22) dos gatos com CHL, foram positivos para FIV, 40,9% (9/22) para FeLV e 31,8% (7/22) marcação para ambos os retrovírus. Na CHN, 85,7% (6/7) positivos para FIV, 57,1% (4/7) para FeLV e 42,8% (3/7) imunorreação para os dois retrovírus. Na CHE, 100% (3/3) dos casos apresentaram marcação para FeLV, 33,3% (1/3) para FIV e 33,3% (1/3) para ambos. Imunomarcação para E. coli foi observada em 27,3% (6/22) dos casos da CHL, 28,6% (2/7) da CHN e em 33,3% (1/3) da CHE. E. coli, Enterococcus sp. e Klebsiella pneumoniae foram os micro-organismos mais frequentes isolados no exame bacteriológico. A visualização da E. coli, através da IHQ no sistema hepatobiliar de gatos diagnosticados com colângio-hepatite associados à inflamação, sugere que a doença se desenvolveu secundariamente à infecção bacteriana ascendente.

Phylodynamics of the Brazilian feline immunodeficiency virus.

Feline immunodeficiency virus (FIV), like other retroviruses, displays large genomic divergence when different isolates are compared. In this study, 31 FIV positive samples of domestic cats from Porto Alegre, RS, Brazil were used aiming at a detailed genomic characterization and a better understanding of the molecular epidemiology of the virus in Brazil. The proviral env genes were partially amplified, sequenced and compared with another 237 sequences from different continents. We identified several Brazilian highly supported clades (A, B1, B2, C and D) that suggest independent events of introduction of FIV in Brazil. Forty six reference-sequences from the GenBank were used with our 31 sequences to infer the virus subtypes. Our sequences belong to the subtype B and three of them result from a recombination with the previously described subtype F. The other 28 Brazilian samples belonging to subtype B and another 46 Brazilian sequences from the GenBank were used to estimate the time to the most recent common ancestor of each Brazilian clade, using a Bayesian approach and a relaxed molecular clock model. The analyses of Brazilian sequences suggest several different entries of the virus in the Brazilian cat population between 1981 and 1991.

Molecular detection of viral agents in free-ranging and captive neotropical felids in Brazil.

We describe molecular testing for felid alphaherpesvirus 1 (FHV-1), carnivore protoparvovirus 1 (CPPV-1), feline calicivirus (FCV), alphacoronavirus 1 (feline coronavirus [FCoV]), feline leukemia virus (FeLV), feline immunodeficiency virus (FIV), and canine distemper virus (CDV) in whole blood samples of 109 free-ranging and 68 captive neotropical felids from Brazil. Samples from 2 jaguars ( Panthera onca) and 1 oncilla ( Leopardus tigrinus) were positive for FHV-1; 2 jaguars, 1 puma ( Puma concolor), and 1 jaguarundi ( Herpairulus yagouaroundi) tested positive for CPPV-1; and 1 puma was positive for FIV. Based on comparison of 103 nucleotides of the UL24-UL25 gene, the FHV-1 sequences were 99-100% similar to the FHV-1 strain of domestic cats. Nucleotide sequences of CPPV-1 were closely related to sequences detected in other wild carnivores, comparing 294 nucleotides of the VP1 gene. The FIV nucleotide sequence detected in the free-ranging puma, based on comparison of 444 nucleotides of the pol gene, grouped with other lentiviruses described in pumas, and had 82.4% identity with a free-ranging puma from Yellowstone Park and 79.5% with a captive puma from Brazil. Our data document the circulation of FHV-1, CPPV-1, and FIV in neotropical felids in Brazil.