Mycoplasmas

Question 1

Mycoplasmas

Which are the species of veterinary importance?

Characteristics of mycoplasmas?

Answer 1

Minimal cells

Small genome

Physiolgoically restricted- highly fastidious

Lack cell wall (peptidoglycan)

Sterols present in cell membrane.

**Host Dependent: Don’t survive long outside of host. Reflected in their physiological restrictions. Require nutrients from the host for survival. **

Fried egg colonies

1. Mycoplasam
2. Ureaplasma

Question 2

What are the virulence mechanisms of Mollicutes?

Answer 2

1. Adhesins
2. competiton for metabolites- allows for physiological disruption
3. degradative enzymes-allows for physiological disruption.
4. cytotoxic metaboites
5. endotoxicity
6. Angitenic variation/ capsule
7. intraphagocytic survival
8. Antigen persistance
9. lymphocyte suppresion superantigenicity
10. assimilation of host cell angitens autoimmunity.

Question 3

Respiratory Mycoplasma Infection:

Answer 3

“Mycoplasma Hyopneumoniae”

1. Inhalation
2. Adherance to ciliated epithelium
3. Colonization of bronchioles/ alveoli

**4.Ciliostasis and ciliotoxicity. **

Question 4

Mycoplasma Hyopneumonia (Porcine Enzootic Pneumonia)

Answer 4

Immunomodulation/ immune evasion

Alveolar and peribronchial inflammation

Mononuclear cell infiltraiton and hyperplasia

Lymph node enlargement

Catarrhal exudation (inflammation of mucus membranes nose & throat)

Consolidation

This is a frequent, chronic infection that can last for months/ years. Not typically life threatening.

Can get secondary consequences.

Question 5

What are the secondary consquences of Mycoplasma hyopneumoniae?

Answer 5

Secondary infection due to immunocompromization from M. hyopneumoniae.

Comes from:

1. Pasteurella multocida
2. Actinobacillus pleropneumonaie
3. Hemophilus parasuis
4. Bordetella bronchiseptica
5. Streptococcus suis

Question 6

Contagious Pleuropneumoniae:

Contagious Bovine pleuropneumonia- Caued by?

Contagious Caprine pleuropneumonia- Caused by?

Answer 6

–> Acute respiratory mycoplasmosis

1. M. mycoides subspp. mycoides
2. M. capricolum subsp. capripneumoniae

Question 7

Erythrocyte Associated mycoplasmas:

Answer 7

1. FHA Feline Hemolytic Anemia:

• Caused by hemobartonella felis
• Mycoplasma hemofelis

2. Porcine Eperythrozoonosis

• eperythrozoon suis
• Mycoplasma hemosuis

Question 8

Infection scheme of Hemotrophic mycoplasmas?

Answer 8

Mycoplasma Heme ‘X’

Entry into circulation

Adhere to erythrocytes causing:

1. Indentations/ rupture (degradative enzymes rupture the RBC) –> erythrocyte lysis –> Anemia
2. Autoimmunity–> erythrocyte lysis–> Anemia