30 – Mycoplasma Flashcards
Microbiological characteristics
- Smallest self-replicating prokaryotes
o Lack cell wall, only have cellular membrane
o Don’t stain well with Gram stains
o *Round, pear shaped or filamentous
o *beta lactams=target cell wall=no drug target! - Limited biosynthetic abilities
o Heavy reliance on host cells
o Genome reduction - Biocontainment level 2 and 3
- Some slow growing
- Specialized requirements to go in vitro
Appearance of mycoplasma colonies
- Fried egg
Specialized requirements to go in vitro
- Extra nutritious media
o Precursors for nucleic acid and protein synthesis (serum)
o Precursors for lipid biosynthesis
Mycoplasma is host associated
- Found on mucous membranes
- Upper respiratory tract
- Genital tract
- Intestinal tract
- *subclinical carriage is CHALLANGEING
- Pathogenic species to animals can survive for SHORT periods (days) in protected environments
It is useful to divide Mycoplasma into
- Hemotrophic: can NOT be grown on agar plates
- Non-hemotrophic: CAN be grown on agar plates
Virulence factors
- Variable surface proteins
- Adhesions
- Lipoproteins
- Capsule
- Biofilm
What does Mycoplasma mycoides cause in cattle?
- Contagious bovine pleuropneumonia
o Very old disease
o 3 major eradication efforts globally
o Only endemic in sub-Sharan Africa
o Currently notifiable to WHOA (Stamping out in Canada)
What is contagious bovine pleuropneumonia (Mycoplasma mycoides) characterized by?
- SEVERE fibrinous pneumonia
o High morbidity and mortality
o Major production losses - *marbling appearance on cut section of lung
Acute disease of SEVERE fibrinous pneumonia (Mycoplasma mycoides)
- High fever
- Severe respiratory distress
Sub-acute to chronic disease of SEVERE fibrinous pneumonia (Mycoplasma mycoides)
- Usually those which have RECOVERED
- Often coughing and progressive cachexia
What is the incubation period of Mycoplasma mycoides?
- 3 weeks to 6 months
How is Mycoplasma mycoides transmitted in cattle?
- Prolonged contact with carriers
What does Myoplasma capricolum cause in goats?
- Contagious caprine pleuropneumonia
o High morbidity and mortality
What is contagious caprine pleuropneumonia (Myoplasma capricolum) characterized by?
- Cough, hypernea, pyrexia
- Weakness, anorexia, nasal discharge
- Progessing to open-mouth-breathing, frothy saliva
How is Myoplasma capricolum transmitted?
- Aerosols
o Shown to travel up to 50m!
Where is Contagious caprine pleuropneumonia found?
- Africa
- Middle east/east mediterranean
- Asia
- *foreign animal disease in Canada
What are the variety of clinical syndromes associated with Mycoplasma bovis in cattle?
- Arthritis
- Pneumonia: caseonecrotic pneumonia (often polymicrobial)
- Genital infections/abortions
- Mastitis
- *infections can be intracellular=therapeutic challenge
What does Mycoplasma bovis do once inside the host?
- Disseminates hematogenously
o Infection of one body site=can progress to infection of another
Where are Mycoplasma bovis organisms maintained?
- By carriers
o Sub-clinical disease, recovered, ID in colostrum and semen
How do you control Mycoplasma bovis?
- No vaccines
- Isolating affected animals if possible
o Ex. don’t milk mastitis animals with same equipment