Test 2 Flashcards
what are the 4 main viral causes of shipping fever
- IBR (infectious bovine rhinotracheitis)
- PI3 (parainfluenza)
- BRSV (bovine resp. syncitial virus)
- BVDV (bovine virus diarrhea virus)
what damage do the following viruses cause to lead to shipping fever
• IBR (infectious bovine rhinotracheitis)
• PI3 (parainfluenza)
• BRSV (bovine resp. syncitial virus)
• BVDV (bovine virus diarrhea virus)
PI3 - damages ciliated epithelium, macrophages
IBR and BRSV - damage ciliated epithelium
BVDV - immunosuppressive: infects lymphocytes and
enhances growth of bacteria
What is the name of each of these viruses
PI3
IBR
BRSV
BVDV
- IBR (infectious bovine rhinotracheitis)
- PI3 (parainfluenza)
- BRSV (bovine resp. syncitial virus)
- BVDV (bovine virus diarrhea virus)
what are the 4 virulence vactors of M. haimolytica
• Fimbriae: Enhances colonization of URT
• Polysaccharide capsule: Inhibits phagocytosis and
complement mediated lysis
• Endotoxin (LPS): Induces proinflammatory cytokines,
toxic to bovine endothelial cells, etc.
• Leukotoxin (Exotoxin): cytolytic activity for leukocytes
and platelets and impairs macrophage function
what is the classic lesion caused by shipping fever
Fibrinous necrotizing bronchopneumonia and pleuropneumonia
what would you generally treat acute pneumonia with from shipping fever
- antibiotics will reduce mortality and development of
chronic pneumonia if treated early - Oxytetracycline and Sulphonamides are usually
effective
what does MIMS stand for
Maximum Immunity, Minimum Stress
what are some effective antibiotics against Psittacosis
macrolide
quinolone
tetracycline
is Clamydophilia psittaci intra or extracellular
Gram (-) bacteria (intracellular)
what is the source and reservior for C. Psittaci
• source and reservoir are infected birds
• does not REPLICATE in the environment, but infective
forms (ELEMENTARY BODIES)
what cells does C. psittaci infect
- Systemic infection
a. infects monocytes and macrophages
key cells that allow systemic spread to target tissues
b. also local spread in intestine, upper/lower respiratory
tract
main clinical signs depend on site of damage
similar to erilichia and rekettsia viruses C. psittaci evades the immune system by…..
Phagolysosomal fusion blocked
- prevents killing of bacteria
why must C. psittaci act as an obligate intracellular pathogen
Replication within the phagosome as reticulate bodies (RB)
• cannot make ATP (energy), lacks cytochromes
→ intracellular space provides protection from host
defenses, and a source of energy for replication
how is C. psittaci able to persist in the environment
Differentiate into elementary bodies (EB) and lyse cells
- Elementary bodies are the infective forms, invade new
cells
Elementary body is stable in the environment;
are “spore-like”
is C. psittaci a reportable Dz?
- If proven, or suspected, C. psittaci infections are a reportable disease
- signs may be very non-specific, should be considered in any bird with lethargy and nonspecific signs of illness
- Serous ocular and nasal discharge,
- diarrhea with excretion of green to yellow urates
- typical differentials are other systemic bacterial and viral infections
how do you test for C. psittaci
Cloacal swab – DIRECT antigen detection
i. ELISA: detection of antigen in secretions and feces
- rapid test, commercial human kits
- lack sensitivity and specificity, especially on normal birds
ii. Culture on cell lines
- sensitive, but takes a long time
- recommended to avoid limitations of other tests
iii. Polymerase chain reaction (PCR) to detect Chlamydophila
DNA
- sensitive and fast
how is psttaciosis treated
Tetracyclines are the drugs of choice, very effective –
• Tx must be prolonged (45 days)
• Dietary calcium should be removed from food because calcium chelates tetracyclines
• Doxycycline more commonly used because it is better absorbed and more slowly eliminated.
• Treated birds should be monitored for signs of doxycycline toxicosis
• depression, decreased appetite, green yellow stained urine and altered hepatic functions).
provide a brief overview of Clamydophila psittaci…
- Systemic infection, affects respiratory tract of parrots and humans (psittacosis) or other birds (ornithosis)
- Obligate intracellular parasite
- Receptor mediated uptake, avoids killing by preventing phagosome-lysosome fusion
- Replicates as reticulate bodies, released from cell as resistant, infectious elementary bodies
- Damages cells by endotoxin, cell lysis, and production of cytotoxins
- Diagnosis in live birds based on direct detection of antigen (ELISA, Culture and PCR) or serology
what are the most common UTI pathogens found
a) >75% are E. coli, Proteus, Klebsiella
b)
what is the source of the most UTI
usually normal flora of the lower UT (distal urethra)
1) usually normal flora of the lower UT (distal urethra)
what is the #1 defense against an UTI
Flushing by urine - URINE FLOW is #1 host defense!
- prevents access to and colonization of the bladder
what are some pathogenic causes of an UTI
- urinary stasis
- mechanical impediments to flow
- damage to epithelial surface that impedes urine flow and promotes bacterial colonization
4 late gestation
virulence factors that prevent bacteria from being washed away - diseases that decrease urine osmolality (renal failure, cushing’s, diabetes)
what are some common pathogens associated with an UTI dependent on PH
acid - rods - E. coli
acid - cocci - Strep, Enterococcus
alkaline - rods - Proteus
alkaline - cocci - Staph
what is the primary source of leptospira?
• Carrier animals and rodents are the main source of infection for other animals
c. Infected animals shed Leptospira through urine (contaminate environment)
• Acutely infected cattle may shed up to 108 / ml
• Recovered dogs can excrete for many months