Section 5: Mycoplasma and Ureaplasma

Question 1

What are the characteristics of Mycoplasma and Ureaplasma

Answer 1

• Lack a cell wall, consequently very pleomorphic
• Cell membrane contains high level of sterols
• Tiniest free living organisms capable of self replication
• Require cholesterol for growth in culture
• Absence of cell wall makes them resistant to any antibiotic that interferes with cell wall synthesis

Question 2

What is the epidemiology of Mycoplasma pneumoniae

Answer 2

• Worldwide distribution
• Estimated that 2 million cases of pneumonia in U.S. per year
• Estimated 20 million cases of other respiratory disease (mild)
• Infection is spread by nasal secretions

Question 3

What is the pathology of Mycoplasma pneumoniae

Answer 3

-Typically -mild respiratory disease
-Primary atypical pneumonia (PAP) or walking pneumonia
• Cough
• Fever
• Headache
• Some patchy findings on chest radiographs

Question 4

What is the autoimmune response due to Mycoplasma pneumoniae

Answer 4

Some antigens on human RBCs are identical to antigens on M. pneumoniae
-This can cause some autoimmune response, but only in some patients

Question 5

What is Ureaplasma urealyticum

Answer 5

T-strain Mycoplasma (T=tiny)
• Produce tiny colonies
• Many infants, mostly girls, are colonized at birth (part of normal flora)
• Approximately 75% of sexually active adults are colonized with U. urealyticum
• Ureaplasma found in urine producing urease to break down urea
• Sexually transmitted
• Opportunistic infections o Nonchlamydial nongonococcal urethritis, not vaginitis
• Can cause neonatal infection