Dr. Romero portion Flashcards
What is the gold standard in virus ID
Virus isolation- but takes too long for clinical
Name the two types of biological assays
Viral plaque and end-point titration of infectivity
Name the 4 physical assays
HA, Ag capture ELISA, EM count, PCR
What does virus isolation look for?
CPE- cytopathic effects like syncitia, intranuclear/intracytoplasmic inclusions
What is a + result in HA
Lattice of cross linked RBCs
Minimum detection for HA in turkey/chicken
10^6/mL
How do you confirm HA
Make antisera of suspected virus, if it inhibits HA, virus confirmed
FeLV - virus type
Gamma retro (think grandma loves cats)
FeLV - diversity due to
mutation and recombination with endogenous retroviruses
FeLV - infection usually due to
genetically distinct but Ag-related exogenous FeLVs
FeLV - virulence traits
In LTRs/promoter of provirus on SU surface glycoprotein
FeLV - vax origin
SU glycoprotein changes alter disease and receptor use
FeLV - symptoms
Lymphosarcoma, myoproliferative dz and anemia, glomerulonephritis, immunopathologic disease, fibrosarcomas
FeLV - lymphosarcoma pathogenicity
6 cellular oncogene dysregulation (c-myc, v-myc, flvi1, flvi2, flit1, fit1)
FeLV - transmission
Horizontal- saliva, tears, urine, feces, milk; vertical- transplacental
FeLV - lymphoma types
- multicentric, alimentary (older), thymic (kittens), unclassified (skin, eyes, CNS);
FeLV - myoproliferative disease types
- RBC myelosis, granulocytic leukemia, erythroleukemia, myelofibrosis;
FeLV - immuno dz types
- glomerulonephritis from Ag-Ab complex in capillaries; Ab-mediated cytotoxicity depleting lymphocytes; immunodeficiency leading to stomatitis, gingivitis, non-healing lesions, abscesses, CRF, etc
FeLV - fibrosarcoma pathogenicity
Recombination of virus to FeSV via V-onc acquisition, multifocal subcu that metastasize, no horizontal spread of FeSV, sarcomas from vax not FeSV
FeLV - dx
Ag immunoassay kits - detect p27 in serum; PCR
FeLV - vax components
env and gag Ag from recombinant canarypox
Bovine leukemia virus- type
Retrovirus
Bovine leukemia virus- target
B-lymphocytes with IgM on surface, monocytes, macrophages
Bovine leukemia virus- symptoms
Mostly asymptomatic; Lymphoma, lymphosarcoma leading to death, persistent lymphocytosis
Bovine leukemia virus- lymphocytosis
high number of circulating B lymphocytes in 30% of cows, only 5% will develop lymphosarcoma
Bovine leukemia virus- transmission
Virus in B cells - transfer in blood or milk- horizontal - proviral DNA in milk, biting insects, bloody tools
Bovine leukemia virus- incubation
3-4 years
Bovine leukemia virus- pathogenicity
Infect B-lymph’s, polyclonal expansion of lymphs, viral transactivating protein (Tax) enhances LTR promoter to increase replication speed
Bovine leukemia virus- diagnosis
huge buffy coat on PCR
Most common cause of LRT dz in cattle
Bovine Respiratory Syncitial Virus
BRSV- virus type
paramyxo- pneumovirinae RNA virus
Bovine Respiratory Syncitial Virus- symptoms
pneumonia, edema, emphysema, secondary bacterial infection, BRDC (bovine respiratory disease complex)
Syncitia
Cell fusion causing many nuclei surrounded by one membrane
Bovine Respiratory Syncitial Virus- pathology
Dstroys ciliated epithelium of lungs, interstitial pneumonia and emphysema on necropsy, syncitia in in bronchi and alveoli
Bovine Respiratory Syncitial Virus- cell targets
Type II pneumocytes and alveolar macrophages
Bovine Respiratory Syncitial Virus- diagnose
RT-PCR, but may get + from modified live vax!!!; Virus isolation with paired sera
Bovine Respiratory Syncitial Virus- vaccine
Formalin-inactivated glycoprotein G might enhance disease - skews Th-2 immune response = release of cytokines, no CD8+ T-cell response
CAE caprine arthritis encephalitis- virus
Leniti- retrovirus RNA!
CAE- transmission
Milk/colostrum (also in utero, birth, saliva/respiratory)
CAE- target
Any WBC rich biological material
CAE- diseases
Chronic joint dz, indurated (hard) mastitis, encephalomyelitis in kids under 6m
CAE- control
Remove kids from infected does immediately after birth, heat colostrum 56 deg for 30 min, no vax or tx
JSRV- disease name
Jaagseitke sheep (beta) retrovirus - Ovine pulmonary adenomatosis
JSRV - CS
Progressive dyspnea due to drowning in own fluid from over-secretion from cells
JSRV - target cells
transforms differentiated lung epithelial cells- Type II pneumocytes - in terminal airways and alveoli
JSRV - transmission and pathogenesis
Aerosolized lung fluids from proviral DNA in 2-pneumocytes, found in lymphoid tissue, macrophages and lymphocytes as well
JSRV- replication
Active replication in restricted to bronchoalveolar epithelial cells
JRSV- dx
No sensitive serological test
JRSV - control
No test, so use strict biosecurity and immediate removal of sheep with CS- DO NOT use lambs from infected ewes
BCoV- virus
Coronavirus RNA
BCoV- replication
URT (nasal gland) and Large Intestine
BCoV- pathogenicity
Destroys epithelial enterocytes lining villi CRYPTS!
BCoV- CS
maldigestion, malabsorption, water/elec loss; usually seen at 3-4 weeks when maternal Ab disappear
BCoV- immunity
Lactogenic IgG1 - can boost pregnant cows pre-birth with adjuvanted vax
BCoV- dx
HA virus readily isolated from feces or nasal swab - add trypsin (take a tryp with corona) observe CPE development, add RBCs for hemadsorption; RT-PCR of Spike or Nucleoprotein genes
BCoV- vax source
S immunogenic protein
Your piglet has diarrhea, what is the virus
TGE
TGE- virus
coronavirus, transmissible gastroenteritis
TGE- pathogeniciy
fecal oral, 18-72 hours later- diarrhea
TGE- target
Villi- not crypts
TGE- dx
Ag/virus detection, Ab detection ELISA for specific S protein, viral nucleic acid detection RT-PCR of S gene
TGE- Ag detection, describe
- stained intestinal impression using IHC or IF labeling of Ab- intestinal cells’ immune reactivity with TGE virus fluorescent Ab
PRCV- porcine respiratory coronavirus- source
TGE mutant with deletion in S protein that changed tropism- large (~600 nt) deletion at 5’ end of S gene
PRCV- target
Only respiratory epithelium (pneumocytes I and II)
PRCV- transmission
Farm to farm airborne
PRCV- effects
Mild, subclinical respiratory disease from Inflammation and necrosis of terminal airways- can become pneumonia
Cause of FIP (feline infectious peritonitis)
Feline enteric coronavirus
FIP- suspected pathogenicity
FEC mutate in host and change to tropism for macrophages- Serotype 2 FEC recombinant with canine corona
FIP- CS
Wet- rapid progression, protein rich frothy fluid in abdomen, pyogranulomas on viscera; Dry- slower progression, little to no abd fluid
FIP- vax
Temperature sensitive mutant IN vax- controversial
BCoV- vax
Low temp vax slow activation in nasal tissue
Orbivirus- pathogenicity
Arthopod vectors in high heat
Orbivirus- name a disease!
Blue tongue virus
Blue tongue virus- transmission
Bugs, transplacental
Blue tongue virus- attachment proteins
VP2 and VP5 on capsid surface for attachment, penetration
Blue tongue virus- proteins for protective antibody immunity
VP2, VP5, VP7!!!!!!
Rhabdoviridae- name two diseases and their genera
Rabies- lyssavirus; vesicular stomatitis in horses - vesiculovirus
Rabies- epidemiology determined via
Examine glycoprotein G for species lineage
Rabies CS
Two clinical forms afte prodromal phase- Furious and dumb/paralytic after
Rabies tx
Vaccine and Ig - effective due to delay between initial replication in muscle cells and entry to nervous system
Rabies vaccines- us
Killed only - better against bat transmission
Rabies- dx
GOLD STANDARD- IF of frozen brain; Negri bodies (intracytoplasmic inclusions) in brain neurons (only reliable if +)
VSV- virus
Rhabdoviridae vesiculovirus (vesicular stomatitis virus)
VSV - geography
Americas/western hemisphere
VSV- differentiate from?
FMD - if horses involved, it’s VSV
VSV- types
NJ- most common, less aggressive; IN- less common, more aggressive
VSV- CS
Oral lesions, excessive salivation
Distemper- virus type (3)
Parmyxo paramyxo morbilivirus
Distemper- lineages
Seven - 2 america, 2 asia, arctic like, european, european wildlife – based on H gene, but close enough to use same vax
Distemper- pathogenicity/target
Respiratory disease that replicates in lymphocytes causing immunodepression
Distemper- viremias
1st- lymphoid replication - fever spike; 2nd - systemic infection - epithelial cells of UG tract
Distemper- immunity
Mediated by F protein and H protein neutralizing antibody
Orthomyxovirus- type
Type A influenze viruses
Orthomyxovirus- morphology
enveloped, segmented, negative ssRNA with 8 gene segments
Type A avian flu virus- source of pandemic
Reassorment of HA/NA genes of two viruses
Orthomyxovirus- surface glycoproteins
HA and NA
Avian influ- reservoir/transmission
Waterfowl reservoir with low pathogenicity, goes high when affecting domestic; inhalation or ingestion
Avian influ- replication site
Nasal cavity- trypsin like enzymes cleave viral HA
Avian influ- pathogenic sequence
KRRETR
Avian influ- other disease similar- contrast
Newcastle disease both have drop in egg production, facial edema, comb/wattle cyanosis - need specific reagents to show influ ability to inhibit hemagglutination
Swine influ virus - CS
Usually sub clinical but can become acute respiratory with concurrent pathogens
Swine influ virus - avoid outbreaks by
All in all out herds
Equine influenza- CS hallmark
Dry, paroxysmal cough, high fever; rapid spread in 24-48 hours
Equine influenza- vax
H3N8 + lineage of regional flu
Canine infectious respiratory disease (CIRDC) - virus
Influ virus H3N8 and H3N2 (new)
CIRDC complex organisms
distemper, adenovirus 2, parainfluenza 5, respiratory corona, penumovirus, bordetella
CIRDC- lineage
Equine H3N8
CIRDC- pathogenicity
Destroys respiratory epithelium, predisposes for secondary
CIRDC- new strain, source
H3N2 from avian origin
CIRDC - compare strains
H3N8 - mild, H3N2- aggressive - 10 times more virus, longer shedding (24 days)
CIRDC vax sequence
6 weeks, then 2-4 w after, then anual
CIRDC- immunity
No lifetime, no significant cellular immunity
BVDV- virus
flaviviridae - pestivirus
BVDV- transmission
Fomites - feed, urine, nasal/oral secretions, feces, placental tissue, transplacental in first half of pregnancy; poorly transmitted from acutely affected animals; Persistently affected will shed for life and pass to offspring
BVDV- disease
Mucosal disease- if pregnant and infected in mid gestation from ncp biotype, persistent infection will be present if offspring survives. Leads to immunotolerance and mutation of ncp to cp- which allows mucosal disease which can cause cytopathic disease
BVDV- dx
Ear notch test with ELISA or RT PCR
BVDV- control
Immediate culling of Ag positive
BVDV vax
Inactivated, no protection for transplacental; do not vax persistently infected- will cause mucosal disease