PBL 2 GROUP 17 by Ashwinie Selvaraj

Foot & Mouth Disease Virus

ashwinieselvaraj — 2019-11-08 12:49:44 UTC

-high morbidity but low mortality
- non-zoonotic
- causes economical losses
- transboundary

Pasteurella multocida serotype b & Brucella abortus

ashwinieselvaraj — 2019-11-08 12:49:44 UTC

Pasteurella multocida
- normal flora in upper repiratory tract
- gram-ve bacteria
- causes pasteurellosis which is a zoonotic disease, can be transmitted through animal bites, scratches or licks

Brucella abortus
- blood-borne pathogen
- intracellular parasite
- gram-ve bacteria
-zoonotic

Haemonchus contortus

ashwinieselvaraj — 2019-11-08 13:02:53 UTC

- common gastrointestinal parasite in ruminants
- infective stage (L3) is ingested by host on pasture, further develops in abomasum and produces eggs passed in faeces
- infestation could lead to anaemia, hypoproteinaemia, submandibular oedema
- favours warm moist environment

Foot & Mouth Disease Virus

ashwinieselvaraj — 2019-11-08 13:06:46 UTC

- Most effective way to diagnose FMDV?
- Which immune response is more important in FMDV?
- How to do DIVA?
- Why is DIVA important?

Pasteurella multocida serotype b & Brucella abortus

ashwinieselvaraj — 2019-11-08 13:06:55 UTC

- Best way to diagnose?
- What vaccines are available?
- What are the limitations of the vaccine?

Haemonchus contortus

ashwinieselvaraj — 2019-11-08 13:07:19 UTC

- What are the obstacles facing effective control?
- Which immune response is more important?
- What is in the vaccines?
- What adjuvants are used?

Foot & Mouth Disease Virus

ashwinieselvaraj — 2019-11-08 13:07:28 UTC

- has 7 major serotypes: O. A, C, SAT-1, SAT-2, SAT-3, Asia-1
- Structural Proteins (VP1, VP2, VP3, VP4) -
- Nonstructural Proteins (3A, 3B, 3C,..)
- gold standard for diagnosing is ELISA (fast, cost effective, not dependent on live virus)
- CMI and humoral immunity are both important
- CMI is important in clearance/killing of virus as they are intracellular pathogens and are able to survive humoral immunity
- DIVA means Differentiating Infected from Vaccinated Animals
- Vaccinated animals: Killed vaccine, not able to synthesize NSP
- Infected animals: Live vaccine

- DIVA is done by:
a. measuring levels of IFN gamma (infectedb. detecting IgA presence; mucosal antibody detection
(infected>vaccinated)
c. NSP antibody detection (present in infected animals only)

- DIVA is important to:
a. control spread of FMDV
b. eradicate FMDV
c. maintain an effective surveillance during outbreak

Pasteurella multocida serotype b & Brucella abortus

ashwinieselvaraj — 2019-11-08 13:07:54 UTC

- bacterial cultures are cost effective and simple whereas PCR is more rapid, sensitive, and specific
-Vaccines:
Pasteurella multocida- alum precipitated vaccine, oil adjuvanted vaccine & broth bacterin
- Broth bacterin provides short and limited protection (6 weeks)
-Alum precipitated vaccine give protection of 4-6 months only and it needs to be stored properly
-Oil adjuvanted vaccine provides protection of 6-9 months but has high viscosity
-All three can cause anaphylactoid reaction (hypersensitivity) which results in drop in milk production or even death (rare)
Brucella abortus- RB51 and S19
- RB51 may not be safe for pregnant cattle, is resistant to rifampicin, failed to be detected by serological tests
- S19 can cause abortion, testicular infection, and it's effectiveness decreases with the increase of bacterial exposure

Haemonchus contortus

ashwinieselvaraj — 2019-11-08 13:08:01 UTC

- difficult to control due to high egg production, drug resistance and rapid larval development
- also has the ability to stay in the dormant stage inside the abomasum until environment becomes favourable again for growth (hypobiosis)
- humoral immunity plays an important role to control infection
- types of antigen found in instestines: contortin, H11, H-gal-GP
- vaccine development: recombinant vaccine of H11 + H-gal-GP (protection, sustainable, 96% egg reduction)