ABSTRACT
OBJECTIVES: Feline immunodeficiency virus (FIV) is a lentivirus that induces AIDS-like disease in cats. Some of the antiretroviral drugs available to treat patients with HIV type 1 are used to treat FIV-infected cats; however, antiretroviral therapy (ART) is not used in cats as a long-term treatment. In this study, the effects of long-term ART were evaluated in domestic cats treated initially with the nucleoside transcriptase reverse inhibitor (NTRI) zidovudine (AZT) over a period ranging from 5-6 years, followed by a regimen of the NTRI lamivudine (3TC) plus AZT over 3 years. METHODS: Viral load, sequencing of pol (reverse transcriptase [RT]) region and CD4:CD8 lymphocyte ratio were evaluated during and after treatment. Untreated cats were evaluated as a control group. RESULTS: CD4:CD8 ratios were lower, and uncharacterized resistance mutations were found in the RT region in the group of treated cats. A slight increase in viral load was observed in some cats after discontinuing treatment. CONCLUSIONS AND RELEVANCE: The data strongly suggest that treated cats were resistant to therapy, and uncharacterized resistance mutations in the RT gene of FIV were selected for by AZT. Few studies have been conducted to evaluate the effect of long-term antiretroviral therapy in cats. To date, resistance mutations have not been described in vivo.
Subject(s)
CD8-Positive T-Lymphocytes , Cat Diseases/drug therapy , Feline Acquired Immunodeficiency Syndrome/drug therapy , Immunodeficiency Virus, Feline/drug effects , Lamivudine/therapeutic use , Reverse Transcriptase Inhibitors/therapeutic use , Animals , Cats , Follow-Up Studies , Molecular Sequence Data , Viral Load , Zidovudine/therapeutic useABSTRACT
BACKGROUND: Feline immunodeficiency virus (FIV) is a naturally occurring lentivirus that infects cats. The primary mode of transmission occurs through bite wounds, and other routes are difficult to observe in nature. FINDINGS: The purpose of this study was to evaluate FIV transmission from queen to kitten in a colony of naturally infected stray cats. With this aim, a queen was monitored over a period of three years. A blood sample was taken to amplify and sequence gag, pol and env regions of the virus from the queen, two kittens and other cats from the colony. CONCLUSION: Phylogenetic analysis showed evidence of queen to kitten transmission.
Subject(s)
Feline Acquired Immunodeficiency Syndrome/transmission , Immunodeficiency Virus, Feline/physiology , Infectious Disease Transmission, Vertical/veterinary , Animals , Cats , Feline Acquired Immunodeficiency Syndrome/virology , Female , Immunodeficiency Virus, Feline/classification , Immunodeficiency Virus, Feline/genetics , Immunodeficiency Virus, Feline/isolation & purification , Male , Molecular Sequence Data , Pedigree , Phylogeny , Pregnancy , Retroviridae Proteins/geneticsABSTRACT
O presente estudo teve como objetivo principal padronizar a técnica de reação em cadeia de polimerase(PCR)para detecção do genoma proviral do vírus da imunodeficiência felina(FIV),um retrovirus associado com a síndrome da imunodeficiência adquirida(AIDS)dos felinos.Avaliamos amostras de sangue de 97 felinos domésticos provenientes da cidade do Rio de Janeiro.Deste total,60 felinos eram sororeativos para anti-FIV e 37 felinos soronegativos, que foram avaliados como grupo controle.O status imunológico destes felinos...Entre as amostras sororeativas,40(67por cento)apresentavam alterações clínicas,sendo que 38 foram classificados na fase de complexo relacionado à AIDS(CRA)e 2 na fase AIDS. Para a extração de DNA utilizou-se QIAmp Blood Mini Kit (QIAGEN).Após a extração,as amostras foram submetidas a PCR para DNA mitocondrial do gene 16s como controle positivo de extração.Para a detecção do genoma proviral do FIV foram selecionados iniciadores que amplificam uma região com 483 pb do gene gag e 471 pb do gene pol.Para a nested PCR foram selecionados iniciadores que amplificam uma região interna com 203 pb do gene gag e 183 pb do gene pol.A especificidade dos iniciadores foi avaliada utilizando amostras de animais sororeativos para o vírus da leucemia felina(FeLV),um retrovirus heterólogo.Quatro protocolos distintos foram avaliados para a região gag e 3 para a região pol,buscando obter o melhor método para amplificação.Das amostras sororeativas,39(65por cento) apresentaram resultado de amplificação para a região gag utilizando os 4 protocolos,e 6(10por cento)para a região pol,utilizando 3 protocolos.Entre as amostras soronegativas,1 felino apresentou resultado de amplificação para a região gag.Em uma 2ªcoleta este felino demonstrou conversão sorológica.O seqüenciamento genômico permitiu avaliar a especificidade dos fragmentos amplificados em 8 amostras,entretanto não foram obtidos resultados conclusivos em relação aos subtipos virais.Os protocolos selecionados para...
