mycoplasma + ureaplasma (RESPIRATORY pathogens)!!! MICROM 442 Deck 17 Flashcards
m. pneumoniae usually found in the upper
lung
m.hominis & m.genitalium & m. fermentans
bladder and lower lungs
ureaplasma urealyticum & u.par found in the
bladder
cell wall?
NO
M. pneumoniae shape
tapered rods
M. hominis & Ureplasma spp shape
coccoid
what is special about their size?
smallest free-living organism and small genome
growth and cultivation
> Fastidious, no single medium
– Generally rich medium + need serum
– Different pH, nutritional requirements
– Add b-lactam, prevent overgrowth
– Monitor growth with pH indicator, not turbidity
– UAB = Ref Lab
Very tiny colonies
37C, 5-10% CO2 (aerobic) or anaerobic
2-4 days M. hominis & Ureaplasma; several weeks for M. pneumoniae
37C, 5-10% CO 2 (aerobic) or anaerobic
- Very tiny colonies (use a microscope)
- Faint blush/haze on plates; liquid culture followed by pH NOT
turbidity (can blind subculture) - M. hominis & Ureaplasma spp -> 2-4days
a. M. hominis – fried egg colonies - M. pneumoniae à weeks
No single medium
- Contain Beta-lactam Abx
- Need ill-defined supplementation (yeast extract)
Alternatives to Culture
- Molecular Diagnosis (PCR), especially early/first 3 wks of dz; as
always, targeted more sensitive than broad-range but only for
target organism - Serology for M. pneumoniae (may cross-react); 4-fold change in
titer from acute to convalescent
Clinical Presentations
i. Respiratory – asymptomatic carriage to community-acquired pneumonia
- Pneumonia
a. Organisms – M. pneumoniae, some cases with Ureaplasma (lung organ transplant patients with high
ammonia in blood)
b. Disease – 2-4wk incubation, enriched during summer and
early fall
i. Think older kids & teens - 5-9yo and 10-17yo and
co-infections fairly common; less common in adults
(2%) - Tracheobronchitis
- Role in Asthma – not well understood
ii. Extrapulmonary – mix of autoimmune and direct infection/host damage
- Joint involvement
a. Especially with agammaglobulinemia (no IgG)
ii. Extrapulmonary – mix of autoimmune and direct infection/host damage
- Encephalitis/meningitis
a. Encephalitis – autoimmune, with strokes, acute psychiatric
illness, paralysis (think Guillan-Barre’)
b. Meningitis/true infections - Especially preterm infants,
vertical acquisition
c. M. hominis may disseminate to CSN, esp in
immunocompromised
ii. Extrapulmonary – mix of autoimmune and direct infection/host damage
- Dermatologic stuff à also autoimmune, rashes all the way to
skin/mucosa sloughing and necrolysis (SJS & TEN -> look up if
curious)
ii. Extrapulmonary – mix of autoimmune and direct infection/host damage
- Miscellaneous – pericarditis (tissue around heart), myocarditis
(muscle of heart), glomerulonephritis
ii. Extrapulmonary – mix of autoimmune and direct infection/host damage
- Cold agglutinin (auto-antibodies) can be detected when performing antibody screen prior to blood transfusion
a. I antigen, auto-IgM mediated hemolysis (usually self-limited)
adhesions/virulence
P1 adhesion
adhesions/virulence
CARDS toxin
– ADP-ribosylation!
adhesions/virulence
– Partial homology to PTx
> MoA → ?NLRP3
> Binds surfactant protein A& annexin A2
> Paralyzes cilia, Increased cytokines
> Airway hyperreactivity
Other
Mycoplasma & Ureaplasma spp
Diseases
Other
Mycoplasma & Ureaplasma spp
Diseases
> Upper urinary tract infx
– M. hominis, ~5% pyelonephritis
Non-gonococcal urethritis
– Males: U. urealyticum, M. genitalium
– Females: Ureaplasma spp (probably)
Cervicitis, Salpingitis, Endometritis and PID
Post-partum fever
Other
Mycoplasma & Ureaplasma spp
Diseases
> Congenital/Neonatal infections
– Preterm
– Meningitis, pneumonia
Immuncompromised
– Disseminated from respiratory/GU sites
– Septic arthritis
– Bacteremia
– Meningitis, Osteomyelitis, Wound infx
Adhesins & Virulence Factors
(Ureaplasma)
> IgA protease
Urease → ammonia production
– C’mon, you predicted this!
Multiple adhesins (poorly characterized)
MB (major antigen from host perspective)
