Mycoplasma Flashcards
Mollicutes General Morphology
“Soft Skin”
- Smallest self-replicating organisms
- NO CELL WALL
- Ubiquitous
Mollicutes - 3 Genera
Mycoplasma
Ureaplasma
Acholeplasma
What are the two types of Mollicutes
Non-hemotrophic & Hemotrophic
What are the common sites of disease in Non-Hemotrophic Mollicutes?
Respiratory Tract - Urinary Tract - Arthritis - Mastitis - Conjunctivitis - Septicemia
What were Hemotrophic mollicutes formerly classified as?
Haemobartonella & Eperythrozoon
What is the disease pattern of Hemotrophic mollicutes?
Hemolytic anemia
Mollicutes Shape? Stain-ability?
Very pleomorphic
-Stains poorly
What do mollicutes have instead of a cell wall?
Trilaminar membrane
Describe the components of the trilaminar membrane of mollicutes
Proteins - Glycoproteins
- Lipoproteins - Phospholipids - Sterols
(Cholesterol for osmotic stability)
Describe the genome of mollicutes
Very small genome
-Extremely plastic (plasmic, phage, transposon components)
What might mollicutes have evolved from?
Clostridium - Streptococcus
Which genera are non-hemotrophic mollicutes?
Ureaplasma and non-hemotrophic mycoplasma
Non-hemotrophic mollicutes Host range?
Often host-specific (not exclusively)
NOT usually zoonotic
Non-hemotrophic mollicutes Culture/ growth patterns
Slow Growth
- CO2-enriched atmosphere at mammalian temps
****-“Fried egg” colonies
Non-hemotrophic mollicutes Sites of infection & presentations
Mainly respiratory and urogenital tract infections
-Occasionally conjunctivitis - arthritis - mastitis - septicemia
Non-hemotrophic mollicutes Reservoir
- Possible normal flora of infected host
- *Mucosal surfaces*
- May survive in moist, cool environments
Non-hemotrophic mollicutes Transmission
Usually *direct contact*
(respiratory or venereal secretions)
Non-hemotrophic mollicutes
Epidemiology
Asymptomatic carriers
- Dairies: mechanical
- Poultry: vertical
- Arthropod suspected
Non-hemotrophic mollicutes
Pathogenesis
Underlying factor –>
attachment to host mucosa –>
Some survive in non-phagocytic cells or fuse with eukaryotic cell membranes –>
Latent infections
Non-hemotrophic mollicutes
Pathogenesis
What are underlying factors for disease susceptibility?
- Age
- Crowding
- Concurrent infections
- Transportation stress
Non-hemotrophic mollicutes
Latent infections -How do they evade the immune system?
- Antigenic variability
- Biological mimicry
Non-hemotrophic mollicutes
Acute septicemic form
Coagulopathy & widespread vascular thrombosis (Resembles gram-neg septicemia)
Non-hemotrophic mollicutes
Chronic infections
Persists through intense inflammatory response & peroxidation
-Tissue damage
Mollicutes Virulence Factors
Peroxide/ Superoxide
Urease
Proinflammatory molecules
IgA proteases
Mollicutes Peroxide/Superoxide role
Disrupt host cell integrity
Mollicutes Urease role
Ureaplasma spp.
Inflammatory & increases pH (ammonia)
Mollicutes Proinflammatory molecules
- Leftover/excessive antigens
- Downregulate or “confuse” CMI & humoral system
Avian Mycoplasmosis 3 causative species
M. gallisepticum
M. synoviae
M. meleagridis
M. iowae
Avian Mycoplasmosis M. gallisepticum Clinical signs chickens vs. turkeys
Chickens: Chronic respiratory disease
Turkeys: Infectious sinusitis
Both: Decreased egg production
*House finch conjunctivitis (US)
Avian Mycoplasmosis
M. synoviae Clinical signs
Turkeys: Sternal bursitis
Synovitis (Lameness, joint swelling, reduced growth)
Subclinical airsacculitis
Avian Mycoplasmosis
M. meleagridis M. iowae
Mainly in turkeys- Clinical signs
Airsacculitis - Skeletal deformities - Growth stunting - Decreased egg hatchability
What disease does Mycoplasma cause in bovine?
Contagious bovine pleuropneumonia (CBPP)
What species of mycoplasma causes CBPP in bovine?
Mycoplasma mycoides subsp. mycoides
(small colony variant)
Describe CBPP in bovine
Mycoplasma mycoides mycoides
Most virulent Mycoplasma in cattle
Respiratory disease