WEEK 17: CELL WALL DEFICIENT ORGANISMS Flashcards
1
Q
Respiratory disease
A
Mycoplasma pneumoniae
2
Q
Mycoplasma are sometimes known as? (eaton agent)
A
Pleuropneumonia-like organism (PPLO)
3
Q
- Do not possess cell walls
- Sometimes referred to as CWD (cell wall deficient)
- Resistant to cell wall active antibiotics
- Penicillins, cephalosporins
- Bonus is that antibiotics can help reduce normal florae
- Slow growing
- Fastidious
- Require cholesterol and fatty acids for growth
- Note these are conditions found in cultures growing eukaryotic cells
- Human sites
A
Mycoplasma
3
Q
- Colonies grow with center imbedded below
agar surface - Thus appear as “fried eggs”
Transmission:
* Direct sexual contact, during delivery,
respiratory secretions, or fomites
* Very susceptible to heat and drying conditions
A
Mycoplasma
3
Q
- Requires arginine
- Turns pink
- Release of ammonium (NH4) from arginine (phenol red
indicator) - Plate to agar
- A8 agar
- Look for characteristic fried egg colonies of a variety of shapes and sizes
- Diene’s or methylene blue stain
- Light blue “egg white”
- Dark blue “yolk”
A
M. hominis
3
Q
Urogenital tract disease
A
Mycoplasma hominis
3
Q
- 2 to 3 weeks
- Headache, low-grade fever, malaise, anorexia, sore
throat, dry cough, earaches - Extrapulmonary complications
- Cardiovascular, central nervous system (CNS), dermatologic, and gastrointestinal problems are rare.
A
M. pneumoniae
4
Q
- Are the smallest self-replicating organisms in nature
- Very difficult to detect
- Common contaminant of cell culture
- Important in research and in virus labs utilizing cell culture
A
Mycoplasma
4
Q
- Likely an opportunistic respiratory pathogen
- Adults with respiratory illness
- Acute immunodeficiency syndrome (AIDS)–related mycoplasma
- Synovial fluid of patients with rheumatoid arthritis
A
M. fermentans (incognitus)
5
Q
- Generally not cultured
- Takes too long, and sensitivity is low
- Use serology
- 2 to 4 weeks apart for fourfold rise in titer
A
M. pneumoniae
5
Q
inflammation of the fallopian tubes
A
Salpingitis
5
Q
- Diseases
- Bronchitis
- Pharyngitis
- Walking pneumonia (primary atypical pneumonia)
- Mostly asymptomatic (over 90%)
- Isolation always considered significant
- 20% pneumonia in general populations
- School-age children and young adults
- 50% in confined settings
- Prisoners, college students, and military personnel
.
A
M. pneumoniae
5
Q
- Initially in liquid media, and watch for pH change
- SP4, Shepard’s 10B, or 2SP broth
- Plate enriched culture, and check for characteristic
colonies
A
M. hominis and U. urealyticum
5
Q
- Infections of the urogenital tract
- Normal florae of the lower urinary tract of women
- Still can cause upper urinary tract infections
- Significant due to infection of fetus
- Chorioamnionitis (infection of placental membrane)
- Congenital pneumonia
- Chronic lung disease in premature infants
- Meningitis of newborns with negative cultures
- 10% of cases of nongonococcal urethritis (NGU) in
men
A
Ureaplasma urealyticum
5
Q
- Has been some association with NGU, cervicitis,
endometriosis, and PID - May lead to tubal sterility
- Very difficult to culture, takes 2 to 3 months
- Interferes with serology for other mycoplasma
A
M. genitalium
