MICR102A - Finals (Part 2)

Which growth factors are required by most Haemophilus species?

X factor hemin, V factor nad

Haemophilus are what type of bacteria morphologically?

Gram negative coccobacilli

Most Haemophilus species are what type of oxygen requirement?

Facultative anaerobes

What atmospheric condition enhances growth of many Haemophilus species?

Increased CO2

Which organism causes contagious pleuropneumonia in swine?

Haemophilus pleuropneumoniae/Actinobacillus pleuropneumoniae

What is another synonym for Haemophilus pleuropneumoniae?

Haemophilus parahemolyticus

Which growth factor does H. pleuropneumoniae require?

V factor

What type of hemolysis does H. pleuropneumoniae exhibit?

Beta hemolysis

Which organism enhances hemolysis of H. pleuropneumoniae on blood agar?

s. ureus

What colony characteristic is seen in H. pleuropneumoniae?

1–2 mm, mucoid, iridescent colonies

What virulence structure is present in virulent strains of H. pleuropneumoniae?

Capsule

What is the transmission route of H. pleuropneumoniae?

Respiratory route

Which pigs are most susceptible to H. pleuropneumoniae infection?

3 month old pigs

Name one predisposing factor for H. pleuropneumoniae infection.

Poor ventilation, inclement weather, concurrent infections

What type of toxin in H. pleuropneumoniae causes vascular damage?

Endotoxin

What is a key effect of endotoxin in H. pleuropneumoniae?

Thrombi, interlobular edema

Severe H. pleuropneumoniae infection resembles what condition?

Endotoxic shock

What virulence factor damages macrophages in H. pleuropneumoniae?

Heat stable cytotoxin

What virulence factor impairs macrophage function in H. pleuropneumoniae?

Heat labile cytotoxin

What is the function of glycoproteins in H. pleuropneumoniae?

Deeper lung penetration

What is the function of the capsule in H. pleuropneumoniae?

Inhibits phagocytosis

What are the main lesions of H. pleuropneumoniae infection?

Bronchopneumonia, fibrous pleuritis

How is H. pleuropneumoniae diagnosed?

Isolation on blood agar with V factor and beta hemolysis

Immunity after H. pleuropneumoniae infection is of what type?

Active, passive immunity

Which organism causes Glässer’s disease?

Haemophilus parasuis

Does H. parasuis require X factor?

No

What is the main lesion in H. parasuis infection?

Polyserositis

What does polyserositis mean?

Fibrinous inflammation of serous surfaces

What phenomenon is associated with H. parasuis growth?

Satellitism

Name one condition caused by H. parasuis.

Respiratory disease, polyserositis

Which virus predisposes infection with H. parasuis?

Swine influenza virus

Which organism causes fowl coryza?

Haemophilus paragallinarum

What CO₂ concentration favors growth of H. paragallinarum?

10% CO2

Which growth factor is required by H. paragallinarum?

V factor

What is the oxygen requirement of H. paragallinarum?

Facultative anaerobe

What type of antigens are present in H. paragallinarum?

Heat labile surface, hemagglutinating antigens

What is HA-L typing based on?

Hemagglutinin antigen

Which strains of H. paragallinarum show HA-L antigen?

Encapsulated strains

How is H. paragallinarum transmitted?

Respiratory route, contaminated water

What increases severity of fowl coryza?

Viral or Mycoplasma infections

Which organism causes thromboembolic meningoencephalitis (TEME)?

Haemophilus somnus, Histophilus somni

Is H. somnus a true Haemophilus?

No

Does H. somnus require X or V factors?

No

What condition enhances growth of H. somnus?

CO2 dependent

Where is H. somnus commonly found?

Nasal, genital tracts of cattle

What lesion is associated with H. somnus?

Fibrinous meningitis

Name one predisposing factor for H. somnus infection.

Shipping stress, climate change, regrouping

Which genus was reclassified from Haemophilus?

Taylorella

Which organism causes contagious equine metritis (CEM)?

Taylorella equigenitalis

What was the former name of T. equigenitalis?

Haemophilus equigenitalis

What is the shape of T. equigenitalis?

Coccobacillary, filamentous

What is the oxygen requirement of T. equigenitalis?

Microaerophilic

Does T. equigenitalis require X or V factors?

No

Where is T. equigenitalis found in males?

Urethral fossa

Where is T. equigenitalis found in females?

Clitoral sinuses, fossa

How is T. equigenitalis transmitted?

Venereal via stallions

What is a key diagnostic finding in T. equigenitalis infection?

Neutrophils in profuse exudate

Pasteurella are what type of bacteria morphologically?

Gram negative pleomorphic coccobacilli

Pasteurella belongs to which family?

Pasteurellaceae

What staining characteristic is seen in Pasteurella?

Bipolar (“safety-pin”) staining

Is Pasteurella motile or non-motile?

Non motile

What are the biochemical reactions of Pasteurella?

Oxidase positive, catalase positive

Does Pasteurella grow on MacConkey agar?

No

What oxygen requirement is seen in Pasteurella?

Aerobic to facultative anaerobic

What are the major pathogenic Pasteurella species?

Multocida, haemolytica

What is the habitat of Pasteurella species?

Commensals or parasites in animals

Name one predisposing factor for Pasteurella infection.

Stress, viral infections, Mycoplasma, poor nutrition

Pasteurella infection damages which two respiratory defenses?

Mucociliary system, alveolar macrophages

What results from Pasteurella damage to respiratory defenses?

Mucus accumulation, pneumonia

Which disease is caused by Pasteurella multocida in livestock?

Hemorrhagic septicemia

Which animals are affected by hemorrhagic septicemia?

Cattle, buffalo, sheep, goats

What season is associated with hemorrhagic septicemia?

Rainy season

What are key signs of hemorrhagic septicemia?

High fever, edema, cyanosis

What lesions are seen in hemorrhagic septicemia?

Hemorrhages, edema, pneumonia

Which disease in poultry is caused by Pasteurella multocida?

Fowl cholera

What are common signs of fowl cholera?

Sudden death, diarrhea, depression

What is the mortality rate of fowl cholera?

10–75%

What lesions are seen in fowl cholera?

Petechiae in heart, swollen spleen

Which disease in rabbits is caused by Pasteurella multocida?

Rabbit pasteurellosis or snuffles

What is “snuffles” in rabbits?

Mild URT infection with mucopurulent discharge

What is shipping fever associated with?

Secondary Pasteurella infection

Which viruses predispose to shipping fever?

Parainfluenza-3, IBR, RSV

What lesion is seen in shipping fever?

Fibrinous bronchopneumonia

What is the major virulence factor of Pasteurella?

Capsule

Which capsular type is most common in Pasteurella multocida?

Type A

What are the two antigen types in Pasteurella?

Capsular and somatic

Which Pasteurella species are zoonotic?

P. multocida, P. canis, P. dogmatis

What human infections are caused by Pasteurella?

Wound infections, septicemia, meningitis

Which antibiotic classes are used for Pasteurella?

Penicillin, ampicillin, chloramphenicol, gentamicin

Brucella are what type of bacteria?

Gram negative coccobacilli

Brucella belongs to which family?

Brucellaceae

What is the oxygen requirement of Brucella?

Aerobic, carboxyphilic

What type of lifestyle does Brucella have?

Facultative intracellular parasite

Which tissues does Brucella prefer?

Erythritol-rich tissues or reproductive organs

Where is erythritol found?

Placenta, fetal fluids, testes

How does Brucella enter the body?

Mucous membranes, skin wounds, genital tract

What are common sources of Brucella infection?

Milk, food, water, uterine discharge

Which cells does Brucella survive in?

Macrophages and neutrophils

How does Brucella evade immunity?

Prevents phagolysosome fusion

What is the main lesion of Brucella infection?

Granulomatous inflammation