mycoplasma + ureaplasma (RESPIRATORY pathogens)!!! MICROM 442 Deck 17

Question 1

m. pneumoniae usually found in the upper

Answer 1

lung

Question 2

m.hominis & m.genitalium & m. fermentans

Answer 2

bladder and lower lungs

Question 3

ureaplasma urealyticum & u.par found in the

Answer 3

bladder

Question 4

cell wall?

Answer 4

NO

Question 5

M. pneumoniae shape

Answer 5

tapered rods

Question 6

M. hominis & Ureplasma spp shape

Answer 6

coccoid

Question 7

what is special about their size?

Answer 7

smallest free-living organism and small genome

Question 8

growth and cultivation

Answer 8

> 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

Question 9

37C, 5-10% CO 2 (aerobic) or anaerobic

Answer 9

1. Very tiny colonies (use a microscope)
2. Faint blush/haze on plates; liquid culture followed by pH NOT
   turbidity (can blind subculture)
3. M. hominis & Ureaplasma spp -> 2-4days
   a. M. hominis – fried egg colonies
4. M. pneumoniae à weeks

Question 10

No single medium

Answer 10

1. Contain Beta-lactam Abx
2. Need ill-defined supplementation (yeast extract)

Question 11

Alternatives to Culture

Answer 11

1. Molecular Diagnosis (PCR), especially early/first 3 wks of dz; as
   always, targeted more sensitive than broad-range but only for
   target organism
2. Serology for M. pneumoniae (may cross-react); 4-fold change in
   titer from acute to convalescent

Question 12

Clinical Presentations
i. Respiratory – asymptomatic carriage to community-acquired pneumonia

Answer 12

1. 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%)
2. Tracheobronchitis
3. Role in Asthma – not well understood

Question 13

ii. Extrapulmonary – mix of autoimmune and direct infection/host damage

Answer 13

1. Joint involvement
   a. Especially with agammaglobulinemia (no IgG)

Question 14

ii. Extrapulmonary – mix of autoimmune and direct infection/host damage

Answer 14

2. 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

Question 15

ii. Extrapulmonary – mix of autoimmune and direct infection/host damage

Answer 15

3. Dermatologic stuff à also autoimmune, rashes all the way to
   skin/mucosa sloughing and necrolysis (SJS & TEN -> look up if
   curious)

Question 16

ii. Extrapulmonary – mix of autoimmune and direct infection/host damage

Answer 16

4. Miscellaneous – pericarditis (tissue around heart), myocarditis
   (muscle of heart), glomerulonephritis

Question 17

ii. Extrapulmonary – mix of autoimmune and direct infection/host damage

Answer 17

5. 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)

Question 18

adhesions/virulence

Answer 18

P1 adhesion

Question 19

adhesions/virulence

Answer 19

CARDS toxin
– ADP-ribosylation!

Question 20

adhesions/virulence

Answer 20

– Partial homology to PTx
> MoA → ?NLRP3
> Binds surfactant protein A& annexin A2
> Paralyzes cilia, Increased cytokines
> Airway hyperreactivity

Question 21

Other
Mycoplasma & Ureaplasma spp
Diseases

Question 22

Other
Mycoplasma & Ureaplasma spp
Diseases

Answer 22

> 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

Question 23

Other
Mycoplasma & Ureaplasma spp
Diseases

Answer 23

> Congenital/Neonatal infections
– Preterm
– Meningitis, pneumonia
Immuncompromised
– Disseminated from respiratory/GU sites
– Septic arthritis
– Bacteremia
– Meningitis, Osteomyelitis, Wound infx

Question 24

Adhesins & Virulence Factors
(Ureaplasma)

Answer 24

> IgA protease
Urease → ammonia production
– C’mon, you predicted this!
Multiple adhesins (poorly characterized)
MB (major antigen from host perspective)

Question 25

Laboratory Detection

Answer 25

> PCR (GU, respiratory)
– Most sensitive early (first 3 wks)
– Est. 40+% sensitive vs 35-40% for serology
– Highly specific
– Multiplex panels
Serology (M. pneumoniae)
– EIA, +/- indirect immunofluorescence (reflex for indet. IgM)

Question 26

Treatment (
Mycoplasma &
Ureaplasma)

Answer 26

> Empiric Abx for most outpatient pneumonia
– Usually azithromycin x5-7days
Macrolide resistance an increasing problem
Single point mutation in 23S rRNA
– Levo/Moxifloxacin both active
Oral tetracyclines for known org
– combo tx in severe infx
No vaccine!