Retroviridae

Retro

backwards

Enveloped

two linear positive-sense single stands of RNA

Reverse transcriptase

transcribes viral RNA to double-stranded DNA

Cytoplasm

DNA copies of the viral genome are synthesized in the ____

Retroviridae

has additional of long terminal repeats (LTR)

LTR

serves as provirus

Integrase

integration into the host’s choromosomal DNA

High mutation rate

has erros during reverse transcription

Recombination

between retroviral genomes occur ____

Endogenous retroviruses

remnants of ancient retroviral infections where copy of reverse transcribed viral DNA is integrated in chromosomal DNA after previous retrovirus infection

Exogenous retroviruses

capable of horizontal transmission

gag

encodes major structural nonglycosylated polyproteins

pro

encodes protease responsible for facilitating viral protein maturation

pol

encodes multifunctional protein that includes reverse transcriptase and integrase enzyme

env

encodes the antigenic surface glycoproteins and transmembrane protein

Oncogenic retroviruses

induce neoplastic transformation in cells

Genus Alpharetrovirus

Avian Leukosis

Genus Betaretrovirus

Jaagsiekte sheep retrovirus

Genus Gammaretrovirus

Feline Leukemia virus

Genus Deltavirus

Bovine Leukemia Virus

Genus Epsilonretrovirus

Walleye Dermal Sarcoma

Genus Lentivirus

lifelong infections; long incubation

Lenti

slow

Genus Lentivirus

Bovine immunodeficiency virus

Genus Lentivirus

Jembrana Disease Virus

Genus Lentivirus

Equine Infectious Anemia

Genus Lentivirus

Feline Immunodeficiency Virus

Genus Lentivirus

Caprine Arthritis Encephalitis

Genus Lentivirus

Visna/Maedi (Ovine Progressive Pneumonia)

Feline immunodeficiency virus infection

shed in saliva

Feline immunodeficiency virus infection

Transmission- through bites

Feline immunodeficiency virus infection

replicates principally in CD4+ (helper) T lymphocytes

Feline immunodeficiency virus infection

Produces progressive deterioration in cell-mediated immunity

Feline immunodeficiency virus infection

Phases:

• acute

• prolonged asymptomatic

• vague clinical signs

• terminal phase

Feline immunodeficiency virus infection

Clinical signs:

• Fever

• leukopenia

• anemia

• weight loss

• lymphadenitis

• chronic gingivitis

• behavioral changes

Feline immunodeficiency virus infection

Common:

Chronic stomatitis and gingivitis

Feline immunodeficiency virus infection

Others:

Respiratory

enteric

skin infections

Feline immunodeficiency virus infection

Diagnosis:

serological testing

ELISA

Immunoblotting

Indirect IFA

Feline immunodeficiency virus infection

Treatment: control secondary infection

Feline immunodeficiency virus infection

Control:

prevention of exposure

Feline immunodeficiency virus infection

no vaccine

Equine infectious Anemia

transmitted mechanically: Haematophagous insects:

Tabanus spp

Stomoxys spp

Equine infectious Anemia

Iatrogenic transmission:

contaminated needles &

surgical instruments

Equine infectious Anemia

replication:

macrophages

monocytes

Kuppfer cells

Equine infectious Anemia

Fever

anemia

thromovytopenia

initiating glomerulonephritis

Equine infectious Anemia

Diagnosis:

serology

detection of serum Ab to core virus protein (p26)

AGID test (Coggins test)

Small Ruminant Lentivirus

Maedi/Visna virus

Maedi

labored breathing/shortness of breath

Visna

neurological sign “shrinkage or wasting”

Small Ruminant Lentivirus

Caprine arthritis-encephalitis virus

Small Ruminant Lentivirus

Frequently subclinical

Small Ruminant Lentivirus

Occurs in infected monocytes

Small Ruminant Lentivirus

Diagnosis:

AGID
ELISA

Small Ruminant Lentivirus

Important sorce:

milk from infected animals