General epizootiology

According to pass papers

Who can enter biosafety level 3 laboratories?

a. Anyone who is wearing BSL-3 appropriate personal protective equipment

b. Anyone who agrees to write down their name as a visitor

c. Authorized staff only, and their stay is controlled and restricted to necessary time

c. Authorized staff only, and their stay is controlled and restricted to necessary time

Level 3 = studies on microbes that are either indigenous or exotic and can cause serious or potentially lethal disease through inhalation (yellow fever, West Nile virus, and the bacteria that causes tuberculosis.)

What are virulence groups of Newcastle disease virus?

a. cytopathogenic, non-cytopathogenic

b. Velogenic, mesogenic, lentogenic

b. Velogenic, mesogenic, lentogenic

Oedema disease of Swine is caused by:

Colibacillosis: Shiga toxin-producing Escherichia coli (STEC) oedema disease: the bacteria produces fimbrial adhesins —> ETEC (Enterotoxigenic E.coli): small intestine

Susceptible species for paratuberculosis:

a. All warm blooded mammals

b. All cloven-hoofed animals

c. All ruminants

b. All cloven-hoofed animals

(Paratuberculosis is a contagious, chronic and sometimes fatal infection that primarily affects the small intestine of ruminants. [1] It is caused by the bacterium Mycobacterium avium subspecies paratuberculosis)

Which is the “gold standard” test for laboratory diagnosis of rabies?

a. Fluorescent antibody test

b. Biological experiment

c. Agglutination assay

a. Fluorescent antibody test

Immunofluorescence

What are the stages of infectious process?

• Incubation period – time interval between exposure to etiological agent and appearance of clinical signs

• Prodromal period – unspecific signs of infection

• Manifestation period – specific clinical signs

• Final period - recovery or death

Causative agent of strangles and susceptible species?

Agent: Streptococcus equi serotype E subspecie equi

Susceptible: Horses and other equines (from 5m to 5yo)

The most susceptible species in listeriosis

a. Sheep

b. rodents

c. humans

a. Sheep

(mostly, and Bo, Su, Eq, Dog, cat, rabbits, poultry, fish, insects)

Foot and mouth diseases is caused by:

Aphtovirus (genus) from family Picornaviridae = small RNA viruses

Which of following diseases are zoonotic:

a. Avian mycoplasmosis

b. Swine vesicular disease

c. Canine infectious hepatitis

c. Canine infectious hepatitis

Infectious hepatitis (also known as canine adenovirus and Rubarth’s Disease), affects the liver and other major organs.

Vesicular stomatitis - causative agent and susceptible species:

O-Mononegavirales, F-Rhabdoviridae, G-Vesiculovirus: Most are vesicular stomatitis causative agent (Eq, Bo, Su. oldest known viral infection) - ZOONOTIC

Causative agent of leptospirosis, way of transmission and reservoir species:

• Agent: F-Leptospiraceae, G-Leptospira: Leptispira interrogans, L. biflexa

• Tr: direct contact (urine if infected animals on MM or urine contaminated soil/water/bedding/food), also by bites, eating infected tissues/carcasses, Transplacental transmission (mother to puppies), by semen

• H: Dog++ (Su, Bo, Hu - zoonotic) / R: Rodents

Marek diseases is caused by:

MDV caused by Gallid herpesvirus 2 (GHV-2)

Marek's disease is a highly contagious viral disease of poultry characterized by T-cell lymphomas and peripheral nerve enlargement. It is caused by Marek's disease virus, a member of the genus Mardivirus, and can be transmitted by direct contact or inhalation

Aujeszky diseases is always fatal for:

a. Pigs

b. Humans

c. Dogs

a. Dogs

Agent: Porcine herpesvirus 1 (PHV-1) (Family Herpesviridae, subfamily Alphaherpesvirinae, genus Varicellovirus)

100% mortality in newborn piglets (5-30% in adult)

Dogs and cats dies in 48h p.i.

Ru die in 2d

Which test is used for evaluation of functional activity of lymphocytes?

• E-rosette test = Erythrocyte rosetting is a phenomenon seen through a microscope where red blood cells (erythrocytes) are arranged around a central cell to form a cluster that looks like a flower.

• Erythrocyte-Ab complement

• Blast formation

• Lymphokine production

• lymphocyte transformation test (LTT) is routinely used in clinical immunology labs to assess lymphocyte function.

• lymphocyte proliferation assay bc dvlping as the result of unfavorable environmental conditions, inadequate nutrition, and immunosuppressive effect of the viruses are also important problems appearing in veterinary medicine.

Name at least 3 clinical signs indication secondary immunodeficiency:

• Occurrence of chronic and recurrent infection

• Concurrent respiratory and gastrointestinal infections

• Diseases caused by microbes usually apathogenic or low-pathogenic

• Outbreak of disease after vaccination

• Failure to respond to antibiotic or chemotherapeutic therapy

Explain the term “acquire specific passive artificial immunity”?

a. Immunity acquired via colostrum, transplacental

b. Immunity acquired after vaccination

c. Immunity acquired through hyperimmune serum

c. Immunity acquired through hyperimmune serum

Passive artificially acquired immunity refers to the injection of antibody-containing serum, or immune globulin (IG), from another person or animal. Application of the antibodies per orally or parenterally. Antibodies are produced in a donor animal by active immunization and these antibodies are given to susceptible animals in order to confer immediate protection

Vaccination = active artificial immunisation

Grades of epizootic process:

a. Sporadic, enzootic, epizootic, panzootic

b. Apparent, inapparent, latent

c. Interepizootic, preepizootic, ascendent, culmination, descended, postepizootic

a. Sporadic, enzootic, epizootic, panzootic

• Sporadic - occurs irregularly

• Enzootic - specific disease is continuously present in a given population or geographical area during longer time period

• Epizootic - occurs in a population or region in excess of normal expectancy

• Panzootic - process occurring over a very wide area and affecting large proportion of the population

Epidemic/epizootic diseases occurrence:

a. Spread in limited time, limited area

b. Spread in unlimited time in limited area

c. Spread in limited time in unlimited area

a. Spread in limited time, limited area

Epizootic - occurs in a population or region in excess of normal expectancy

• Epidemic / epizootic (outbreak: an increased or mass occurrence of cases in a particular time and space)

• Pandemic / panzootic (mass occurrence of a disease in many countries or continents);

• Endemic / enzootic (a long-term or permanent occurrence of a disease or its agent in a certain locality or area, for instance in a natural focus).

Secondary source of infectious diseases is:

a. Where the etiological agent survives and multiplies (animal, human, vector, etc.)

b. Where the etiological agent survives and does not multiply

b. Where the etiological agent survives and does not multiply

SOURCE OF ETIOLOGICAL AGENTS

• Primary source - where the etiological agent survives and multiplies (animal, human, vector,etc)

• Secondary source - where the etiological agent survives and does not multiply

What are forms of infectious process according its duration?

• Peracute – within a very short time – first clinical signs – the animal dies

• Acute – clinical signs – few days up to 2 weeks

• Subacute – clinical signs – 2 weeks up to 1 month

• Subchronic – clinical signs – few months

• Chronic – clinical signs – many months

What are forms of infectious process according its manifestation?

• Apparent: (typical, atypical, abortive) visible clinical signs

• Abortive: immune system eliminates infective agent (only incubation and prodromal period)

• Inapparent: no visible clinical signs, animals infected can be a source of

  infection (highly risky group).

• Latent: etiological agent / disease exist in the organism but have not yet manifested. NO complete recovery, infective agent is hidden in body and wait far best moment to leappear (like Herpesvirus)

Univariate epidemiological analysis is:

a. Especially useful for testing the possible casual association between a number of potential risk factors, or variables and a result of interest

b. The simplest approach to exploring the association between a potential risk factor (variable) and a result of interest

c. An interactive exchange of information and opinions throughout the risk analysis process

b. The simplest approach to exploring the association between a potential risk factor (variable) and a result of interest

Descriptive methods in epizootiology is based on:

a. Reveal the etiological agents and their sources and environmental factors in space and time

b. Collection, compilation a processing results of diagnostic activities

c. Evaluation of true epizootiological situation and decision for epizootiological strategy, programs and measures

b. Collection, compilation a processing results of diagnostic activities

Methods of epizootiology

• Diagnostics methods (reveal the etiological agents and their sources and environmental factors in space and time)

• Descriptive methods (collection, compilation a processing results of diagnostic activities)

• Analytical methods (evaluation of true epizootiological situation and decision for epizootiologicla strategy, programmes and measures

• Statistical methods (calculations and principles of probability, epizootiological

  indicators)

• Experimental methods (confirmation of the epizootiological hypotheses and

  new methods development and testing)

• Theoretical methods (generalisation of finding and practical experience)

List 3 methods alternative to the use of living laboratory animals:

• Cell culture

• Tissue culture

• Computer simulation

• Invertebrate, yeast, danio rerio fish, nematode (Caenorhabditis elegans), avian chorioallantoic membrane

Which are the correct disadvantages of the chorioallantoic membrane (CAM) method?

a. Physiology of mammals can be different than of birds, some avian reagents are hard to obtain, vasculogenesis

b. Physiology of mammals can be different than of birds, low cost, rapid development

c. Physiology of mammals can be different than of birds, rapid development, presence of avian Krebs cycle

a. Physiology of mammals can be different than of birds, some avian reagents are hard to obtain, vasculogenesis

What does confluence describe in the context of cell cultures?

a. The flow of cells in a liquid medium

b. Proliferation under the appropriate conditions until they occupy all of the available substrate

b. Proliferation under the appropriate conditions until they occupy all of the available substrate

Sabourad’s glucose agar is used for cultivation of:

a. Rickettsias

b. Leptospiras

c. Yeasts

c. Yeasts

Sabouraud Dextrose Agar (SDA) is used for the isolation, cultivation, and maintenance of non-pathogenic and pathogenic species of fungi and yeasts

PCR methods are methods for:

a. Direct detection of pathogen

b. Undirect detection of pathogen

c. Combinated

a. Direct detection of pathogen

Cytopathic effect is:

a.     Genetic mutation of cell culture after virus infection

b.     Monolayer duplication after virus inoculation

c.      Destruction of the cells after virus inoculation

c.      Destruction of the cells after virus inoculation

Cytopathic effect (CPE), structural changes in a host cell resulting from viral infection. CPE occurs when the infecting virus causes lysis (dissolution) of the host cell or when the cell dies without lysis because of its inability to reproduce

What are the main reagents in ELISA test:

• Immunosorbent = Solid support which has been coated Ab or Ag

• Conjugate = Ag or Ab conjugated enzyme —> Ab or Ag: High purified IgG / enzyme: Horsradish peroxidase (HRPO) labelled secondary Ab specific to the Ab of the sample

• Substrate (of the enzyme): chromogen = orthophenyldiamin (OPD) - orange ; 5-aminosalicyl acid (5 AS) - dark brown ; tetramethylbenzidin (TMB) - blue ; p-nitrophenyl phosphate (with Alkaline phosphatase) - yellow

Explain the term “acquire specific active artificial immunity”?

a.     Immunity acquired after vaccination

b.     Immunity acquired via colostrum, transplacental

c.      Immunity acquired after infection

a.     Immunity acquired after vaccination

Explain the term “acquire specific active natural immunity”?

a.     Immunity acquired after vaccination

b.     Immunity acquired via colostrum, transplacental

c.     Immunity acquired after infection

c.     Immunity acquired after infection

Explain the term “acquire specific passive natural immunity”?

a.     Immunity acquired via colostrum, transplacental

b.     Immunity acquired after infection

c.      Immunity acquired through hyperimmune serum

a.     Immunity acquired via colostrum, transplacental

What is epizootiological triad?

Epizootic process is a biological, dynamic and multifactorial phenomen based on a complex and continuous interaction among animal population, etiological agents and environment

Stages of epizootic process are:

a.     Sporadic, enzootic, epizootic, panzootic

b.     Apparent, inapparent, latent

c.      Interepizootic, preepizootic, ascendent, culmination, descended, postepizootic

c.      Interepizootic, preepizootic, ascendent, culmination, descended, postepizootic

• Interepizootic stage - period btw postepizootic stage and outset of epizootic process activation

• Preepizootic stage - population specific immunity is reduced

• Ascending stage

• Culmination stage

• Descending stage

• Postepizootic stage

Source of infection is:

a.     Macroorganismus, in which etiological agent survives, multiplies and is excreted

b.     Macroorganismus, in which etiological agent survives, multiplies

c.      Macroorganismus, in which etiological agent survives and is excreted

a.     Macroorganismus, in which etiological agent survives, multiplies and is excreted

Source of infection when the disease agent multiplies there, not requiring animal host for its continued survival

Abortive infection is:

a.     Infection causing abortion

b.     Fetal infection

c.      Infection disappearing after prodromal period

c.      Infection disappearing after prodromal period

Molecular epizootiology is based on knowledge from:

a.     Epizootiology and molecular biology

b.     Epizootiology and immunology

c.     Epizootiology and genetics

a.     Epizootiology and molecular biology

Hazard in epidemiology is defined as:

a.     Set of circumstances that could lead to harm, such as presence of pathogens, inappropriate storing of food, chemicals, electricity…

b.     The chance, high or low that somebody could be harmed by these and other hazards, together with an indication of how serious the harm could be

c.      Analysis and evaluation of the risk associated with that hazard (risk analysis, and risk evaluation)

a.     Set of circumstances that could lead to harm, such as presence of pathogens, inappropriate storing of food, chemicals, electricity…

Diagnostics methods in epizootiology are based on:

a.     Reveal the etiological agents and their sources and environmental factors in space and time

b.     Collection, compilation a processing results of diagnostic activities

c.      Evaluation of true epizootiological situation and decision for epizootiological strategy, programs and measures

a.     Reveal the etiological agents and their sources and environmental factors in space and time

Statistical methods in epizootiology are based on:

a.     calculations and principles of probability, epizootiological indicators

b.     confirmation of the epizootiological hypotheses and new methods development and testing

c.      generalisation of finding and practical experience

a.     calculations and principles of probability, epizootiological indicators

Analytical methods in epizootiology are based on:

a.     Reveal the etiological agents and their sources and environmental factors in space and time

b.     Collection, compilation a processing results of diagnostic activities

c.      Evaluation of true epizootiological situation and decision for epizootiological strategy, programs and measures

c.      Evaluation of true epizootiological situation and decision for epizootiological strategy, programs and measures

experimental methods in epizootiology are based on:

a.     calculations and principles of probability, epizootiological indicators

b.     confirmation of the epizootiological hypotheses and new methods development and testing

c.      generalisation of finding and practical experience

b.     confirmation of the epizootiological hypotheses and new methods development and testing

theoretical methods in epizootiology are based on:

a.     calculations and principles of probability, epizootiological indicators

b.     confirmation of the epizootiological hypotheses and new methods development and testing

c.      generalisation of finding and practical experience

c.      generalisation of finding and practical experience

Pandemic/panzootic diseases occurrence:

a.     Spread in limited time, limited area

b.     Spread in unlimited time in limited area

c.      Spread in limited time in unlimited area

c.      Spread in limited time in unlimited area

Ticks are vectors in:

a.     West Nile

b.     Ehrlichiosis

c.      Dengue

b.     Ehrlichiosis

West Nile virus (WNV), a mosquito-borne arbovirus

Dengue: by Aedes spp of musquitoes

Causative agent of Rift Valley Fever and way of transmission:

• Causative agent: Phlebovirus (G) from F Bunyaviridae (part of Arboviral infectious diseases)

• Transmission: direct or indirect contact with the blood or organs of infected animals. through the handling of animal tissue during slaughtering or butchering, assisting with animal births, conducting veterinary procedures, or from the disposal of carcasses or fetuses ; by inoculation ; bites of infected mosquitoes, most commonly the Aedes and Culex mosquitoes and by hematophagous (blood-feeding) flies is also possible.

• Rift Valley fever (RVF) is a viral zoonosis that primarily affects animals but also has the capacity to infect humans. Infection can cause severe disease in both animals and humans.

Etiological agent a susceptible species in Bluetongue

Agent: Orbivirus (G) from F-Reoviridae

Division of the Newcastle disease virus strains according to their pathogenicity:

• Lentogenic – low/non virulent – used for vaccines

• Mesogenic – intermediate virulence

• Velogenic – Highly virulent, hemorrhages, 100% death

Rinderpest is caused by:

• Agent: F of Paramyxoviridae —> SubF: Paramyxovirinay —> G: Morbillivirus

• Pest bovine

Way of tularemia transmission:

a. In Humains:

b. in animals:

b. in animals: vector (all blood suckling arthropod : Ixodes, Amblyoma, Dermacentor, Haemaphysalis). The animal reservoir is the rodent (sheep, pigs, cattle, dogs, cats).

a. In Humains:

• Ingestion : contaminated food, water

• Inhalation in infected dust (bioterrorist)

• Direct contact with infected animal (through mucosa)

• Blood sucking parasites – ticks, flies, mosquitoes

• Biting, scratching by dogs, cats

• Reservoirs – rodents, rabbits, hares !!

Streptococcal meningitis of pigs can infect:

a.     Pigs only

b.     Pigs, humans

c.      Pigs, wild boars

b.     Pigs, humans (but rare in Humans)

Etiological agent and susceptible species of glanders:

• Agent: Burkholderia mallei

• Susceptible H: horses (Hu bc zoonotic)

Botulisms is:

a.     Aerogenic infections

b.     Alimentary infections

c.      Aerobic infections

b.     Alimentary infections

Clostridium botulinum: G+, rod-shaped, anaerobic, spore-forming, motile

What is the correct way of packaging a liquid sample containing potentially infectious material?

a.     First receptacle containing the sample (leak proof test tubes…), secondary packaging made of plastic (biohazard bag)

b.     First receptacle, absorbent material, secondary packaging, outer packaging of adequate strength, all of these must be leak proof

c.      First receptacle (leak proof), secondary packaging (leak proof), outer packaging

b.     First receptacle, absorbent material, secondary packaging, outer packaging of adequate strength, all of these must be leak proof

What is the practical difference in working in a BSL-3 and a BSL-4 level?

a.     In BSL-4, you need a positive pressure suit

b.     In BSL-4, you need to wipe all the surfaces twice after you are done working for the day

c.      In BSL-3, you need a positive pressure suit

a.     In BSL-4, you need a positive pressure suit

Young ruminants are born:

a.     Agammaglobulinemic

b.     Hypogammaglobulinemic

c.      Hypergammaglobulinemic

a.     Agammaglobulinemic

Aleutian diseases of mink is caused by:

• Agent: Amdovirus

• Parvovirus infectious disease

Types of the cell culture according to the way of cultivation:

a.     Monolayers, suspensions, microcarriers culturing

b.     Primary, established

c.      Heteroploid, diploid

a.     Monolayers, suspensions, microcarriers culturing

• Monolayer = a single layer of cells growing on a surface.

• Suspension culture = a type of culture in which cells multiply while suspended in medium.

• Microcarrier culturing = cells grow on the microcarriers in vessels with circulating medium.

Types of the cell culture according to the growth potential:

a.     Monolayers, suspensions, microcarriers culturing

b.     Primary, established

c.      Heteroploid, diploid

b.     Primary, established cell lines

Primary from fresh tissue

Established = permanent cell lines

Rose Bengal test:

a.     Bacteriological test for detection of the presence of bacteria Brucella abortus

b.     Staining methods for direct microscopic detection of Brucella abortus

c.     Serological test-slide agglutination for detection of the presence of antibodies against Brucella abortus

c.     Serological test-slide agglutination for detection of the presence of antibodies against Brucella abortus

RBT: pink colour reagent, for brucellosis detection

Which enzyme is not part of conventional PCR reaction mix?

a.     Reverse transcriptase

b.     Taq DNA polymerase

c.     Proof reading DNA polymerase

a.     Reverse transcriptase

It is in RT-PCR

Brucella agar:

• Brucella medium is a modified medium formulated to support a luxuriant growth of other fastidious bacteria also such as Streptococci, pneumococci, Listeria, Neisseria meningitides, and Haemophilus influenzae.

• medium agar, farell’s medium

FIV way of transmission:

bite wounds from an infected cat.

African horse sickness virus: agent, host, vectors

• Agent: Orbivirus (F Reoviridae)

• Vector: mosquitoes

• H: equines

• Location: RT, CNS, cardio

Tick encephalitis agent:

Flaviviruses (arboviral infectious diseases)

Principal of AGID (agar gel immunodiffusion test):

immunoprecipitation line due to binding of Ag-Ab

A diagnostic test using serum (the fluid, non-cellular part of blood) that detects antibody produced in response to infection. Serum is placed in a well in the agar and a MAP antigen preparation is placed in a nearby well. These two test components passively diffuse out of the well into the agar. If the serum sample contains antibodies to antigens of MAP they bind, forming an interlaced antigen-antibody complex that precipitates in the agar. The precipitate is visible to the unaided eye as a thin white line.

Cats and dogs born:

a.     agamma

b.     hypergamma

c.      hypogammaglobinemic

c.      hypogammaglobinemic

Transmission of avian influenza (orthomyxovirus):

Direct contact, discharges of infected birds, secretion from nose/mouth/eyes

Agar of mycobacteriosis

dermatophyte test medium=sabourad’s glucose agar (with ATB)

Which staining methods is used for microscopic detection of mycobacteria?

Ziehl-Nielsen (staining acid fast bacilli)

Main reagents of PCR:

primers, enzymes(Tag polymerase) DNA sample, dNTP

Principal of hemagglutination inhibition test

HIT = Ability of the specific antibodies to inhibit haemagglutination activity of some viruses (hemagglutinin) (parvovirus, parainfluenza virus, adenovirus,

Positive serum- inhibition of the blood cell agglutination-button

Principle of VNT:

• Highly specific test based on the neutralisation of the virus by specific antibodies in serum tested

• Cytopathic effect of the virus in cell culture is blocked

• Positive serum contains specific antibodies that neutralisedvirus and consequently virus can not damage the cells (CPE)

Staining for brucella

Stamp’s modif of Zielhl-Nielsen’s

Etiological agent of swine vesicular disease

Family Picornaviridae, genus enterovirus.

Etiological agent of swine desentery

Brachyspira hyodysenteriae, (B.pilosicoli)

Positive result of CFT (complement fixation test)

NO haemolysis

For: Paratuberculosis (A), FMD (A), Q-fever, Vesicular stomatitis, Brucellosis, Babesiosis (A), Bovine pleuropneumonia, African horse fever, Infectious pleuropneumonia of goats

Division of media used for the cell culture

a.     Liquid, solid

b.     Natural and synthetic 

c.      Protein-based, sugar-based

b.      Natural and synthetic 

Strain of brucella in horse

Brucella abortus

Agent of peste des petits ruminants:

Morbillivirus (paramyxovirus infections)

Susceptible species of FMD:

• Host : cattle, swine (sheep and many species of wildlife)

• CLOVEN-HOOFED domestic and wild animal species, human can also infected (zoonosis)

• EXTREMELY contagious

• Major global animal health pb

Agent of the avian bronchitis:

Avian infectious bronchitis CV = gammacoronavirus

In blocking ELISA, positive result is:

a. Change of color

b. No color

b. No color

Blocking ELISA: for Ab

• Purified Ag bind to the solid phase —> Add Serum under tested

• Incubation, washing

• Labeled Ab against Ag added

• Negative colour reaction – presence of Ab in investigated serum

• Positive colour reaction – no Ab

Give an example of facultative pathogens

• Candida albicans

• Staphylococcus aureus

• Streptococcus

Animal notifiable diseases are reported to

1. Organisation of International disease elimination

2. World health organisation

3. World organisation for animal health

3. World organisation for animal health

What are ways of etiological agents transmission?

• Alimentary tract: eg. parvovirus, coronavirus and rotavirus

• RT: All viruses that passes in air, eg. herpesvirus, influenza

• Skin (dermatogenic infection): through damaged or undamaged skin

• Urogenital tract

• Mammary gland (lactogenic infection) - mastitis is poly-etiological, either through teat local or skin systemically.

• Conjunctiva

• Umbilical infection

• Accidental entry

What test is virological

1. Virus neutralisation

2. PCR

3. Western blot

1. Virus neutralisation

• Virology:

  • VNT: estimate the capacity of Ab when mixed w Ag in vitro to neutralise its biological activity = very sensitive and specific

  • Detection and identification of viruses: evaluation of CPE

  • Production of viruses for vaccines

  • Haemadsorption test

  • IF

• PCR

• WB: for prions detection

• Serology: ELISA, IDT, KFT

Complement fixation test is used for detection of:

1. Antigen

2. Antibody

3. Viral genome

2. Antibody

CFT:

• detection of Ab in the serum

• Ag + serum Ab + complement —> immunocomplex + complement

• For paraTBC, FMD, QF, vesicular stomatitis, brucellosis, babesiosis, Bo pleuropneumonia, African horse fever

In sandwich ELISA, positive result is

1. Change of color

2. No color

1. Change of color

• Highly sensitive method of Ag detecting

• Coating all surface of well with specific Ab (capture antibody)

• The Ag solution is then added » Ag bound by capture Ab

• Washing

• Specific Ab-Enzyme labelled antiglobulin-added

• Substrate

• The intensity of the colour reaction » related directly to the amount of Ag

What is tropisms of pathogens?

• Tropism = location or predication site of the pathogen in the susceptible hosts

• Monotropic = EA found in only 1 organ or system (RT or GIT or UT)

• Polytropic = EA found in more organs or systems

  • Pantropic = multisites in organisms

Name at least 3 tests for cellular immunity evaluation:

• Chemotaxis in agarosis

• Adherence

• Ingestion: of bacteria, yeast, particle - MSHP

• Digestion: test NBT

What is the role of colostral immunity

• protection against septicaemia and organ infection

• local protection of intestine (IgA)

• GIT – multiplication of bacteria

Clinical signs indicating failure of passive transfert of immunity (FPT)

• Age: 3-5 days old

• Profuse diarrhoea and dehydratation: very fast and lead to death in newborns

• Respiratory or systemic infections

• Laboratory findings:

  • Total Ig level in foals < 48 g/l, in calves < 42 g/l

  • Bacteriology – common environmental microflora found in faeces, blood,..

  • Necropsy – gastronenteritis, pneumonia, lymphoid atrophy

What sample is taken for rabies diagnosis?

1. Saliva

2. Blood

3. Brain

BRAIN

Rabies: head + 2 vertebras or the whole carcasse in small animals

Which medium is used for cultivation of salmonella

1. MacConkey agar

2. Tween agar

3. Sabourad agar

MacConkey agar

• Sabouraud Dextrose Agar (SDA) is used for the isolation, cultivation, and maintenance of non-pathogenic and pathogenic species of fungi and yeasts (Candida albicans)

• MacConkey agar is a selective and differential culture medium for bacteria. It is designed to selectively isolate Gram-negative and enteric (normally found in the intestinal tract) bacteria and differentiate them based on lactose fermentation.

  • Pink = Lac positive species: Escherichia coli, Enterobacteria, Klebsiella 

  • White = Lac negative species: Salmonella, Proteus, Yersinia, Pseudomonas

Which method is used for microscopic detection of fungi

1. Native with KOH

2. Stamp

3. Dark field microscopy

Native with KOH

• Native prep. Live motile leptospira

• Dark field microscopy: blood cells and parts of a cell, tissue sections, yeast, bacteria, algae, various kinds of invertebrates, protists and metazoans, pond water, soil infusions, hay, precious stones such as diamonds, and fractures on metals.

What are the advantages of real time PCR comparing with classical PCR?

• Amplification, detection, quantification and evaluation are in a closed system = no need to open the test tube

• No need for post-amplification procedure to analyse —> reduction of contamination risks

• Fast realisation

• Accurate NA quantification in sample

• High specificity, minimum amount of input material

• Disadvantages: possible degradation of fluorescently labeled components, high sensitive methods, need expertise in data analysis, more demanding introduction of new detection system

• Real-time qPCR: principle consists in the hybridization of a fluorescently labeled oligonucleotide (probe or primer) to the template