Test 3- Mollicutes Flashcards
Mollicutes
Generals + Genera
Means “soft skin”; smallest self-replicating organisms
– No cell wall
– Ubiquitous
• Genera
– Mycoplasma
– Ureaplasma
– Acholeplasma
Mollicutes Clinical Manifestiations
• Subclinical to severely debilitating or fatal diseases in many species
– Clinical manifestations for non-hemotrophic molllicutes
————–Respiratory tract infections
————–Urinary tract infections
————–Arthritis, mastitis, conjunctivitis, septicemia
– Hemotrophic mollicutes
————— Formerly Haemobartonella(not bartonella encelli- cat scratch fever) and Eperythrozoon
—————- Hemolyticanemia
Morphology of Mollicutes
Very pleomorphic
Stain poorly
No cell wall
– Trilaminar membrane
- Proteins
- Glycoproteins
- Lipoproteins
- Phospholipids
• Sterols
–———— Cholesterol for osmotic stability
–Some have carbohydrate capsules
Very small genome
– Extremely plastic
• Plasmid,phage,and transposon components
– May have evolved from Clostridium-Streptococcus
Non-hemotrophic Mollicutes
• Includes Ureaplasma and non-hemotrophic Mycoplasma
— PPLO: Pleuropneumonia-like organisms
– Often host specific (but not exclusively)
——————–Usually not zoonotic
– Can be grown on specialized axenic media
———————Slow growth
———————-Carbon dioxide enriched atmosphere at mammalian temperatures
———————-“Fried egg” colonies
– Cause respiratory and urogenital tract infections
——————Occasionally conjunctivitis, arthritis, mastitis, and septicemia
Ecology
• Reservoir
– Usually t_he host they infect_ (normal flora?)
– Mucosal surfaces
– May survive in moist, cool environments
• Transmission and Epidemiology
– Usually direct contact
———————-Respiratory or venereal secretions
– Asymptomatic carriers often introduce organism
– Mechanical transmission in dairies
– Vertical transmission in poultry
– Arthropod transmission is suspected
Pathogenesis
stressed animals are more common to get these infections
immune response is quite significant– when the immune response
Inflammatory response can lead to TISSUE DAMAGE
Virulence Factors
• Peroxide/Superoxide
– Disrupt host cell integrity
• Urease
– Ureaplasma sp.
– Inflammatory and increases pH (ammonia)
• Others
– Proinflammatory molecules
——————— Leftover or excessive antigens
———————– Cell mediated and humoral immunity is activated; but many Mycoplasma directly downregulate or “confuse” the system
– IgA proteases(muscoal surfaces IgA is the first line of defense—- so the bacteria attach IgA first!)
Avian Mycoplasmosis
Important economically
Reportable in the US
– M. gallisepticum
• Chronic respiratory disease chickens
• Infectious sinusitis in turkeys
• Decreased egg production
• House finch conjunctivitis (Eastern US)
– M. synoviae— not as much economic impact as above
• Synovitis
–————- Lameness, joint swelling
–————– Reduced growth
- Sternal bursitis in turkeys
- Subclinical airsacculitis
M. meleagridis and M. iowae mainly in turkeys
• Airsacculitis, skeletal deformities, growth stunting, decreased egg hatchability
Bovine
Contagious bovine pleuropneumonia (CBPP)
– Mycoplasma mycoides ssp. mycoides (small colony variant)
• Most virulent Mycoplasma in cattle
• Reportable in US
• Respiratory disease- Mostly
– Subclinical and persistent
– Occasionally acute and/or fatal presentation
– Respiratory distress, coughing, nasal discharge, lethargy
— severe emmaciation
Microabsyses in lungs from Mycoplasma CBPP;
other images- fibrins pneumonia
Mycoplasma Mastitis
M. Bovis, M. Californicum, and M. canadense
- M. alkalescens and M. bovigentialium
- drop in milk production
- milk becomes thick and intermixed wtih watery and purlent secretion
- udder can be swollen and the four quarters can be affected
- disseminated infection can follow
enlarged supramamary lymphnodes- pic
Bovine
• Urogenital tract infections
- – Mycoplasma bovigenitalium*
- – Ureaplasma diversum*
– Seminal vesiculitis in bulls
– Granular vulvitis, vaginitis, endometritis, and abortions
– Normal commensal organisms of the lower urogenital tract
Caprine/ Ovine
- Contagious caprine pleuropneumonia
-M. capricolum subsp. capripneumoniae
- similar to bovine condition
- Contagious agalactia of sheep and goats
- M. agalactiae and M. putrefaciens
- febril mastitis
- arthritis and conjuctivitis
————– above in bold are reportable in the USA
-M. mycoides ssp. mycoides (large colony variants)
——- mastitis, pneumonia, bursitis, and arthritis in adults
——- rapid fatal septicemia in kids
- M. mycoides spp. capri
——— pleuropenumonia
Porcine
Porcine
Porcine Enzootic Pneumonia(PEP)
– M.hyopneumoniae
– Chronic respiratory disease
– High morbidity, low mortality
– Chronic non-productive cough,unthrifty appearance,decreased weight gain
M. hyorhinis
– Systemic infection in young pigs (3-10 weeks)
– Fever,anorexia,listlessness
– Arthritis,lameness
– Polyserositis
M. hyosynoviae
– Arthritis in growing pigs (3-6 months)
– Lameness
Feline Infectious Anemia
Mycoplasma haemofelis
Concurrent infections with FIV or FeLV
Free roaming tom cats
Arthropod vector (?)
Peracute, acute, chronic
– Fever, anemia weakness, jaundice
Differentials:
–———-Autoimmune anemia
———–– Babesia
–————Cytauxzoon felis
Treatment
–———- Blood
–———- Doxycycline
———–– Flea control
CBPP
