Lecture 9 Flashcards
Conjugative transfer
-most important means of spreading
antibiotic resistance and virulence factors among bacteria.
-uses Pili to exchange material
Transduction
-phage injects its DNA
-
Transformation
-uptake of naked DNA leading to transformation
Actinomyces israelii
-Branching Filamentous Bacteria
• Gram positive
• Anaerobic
What disease can actinomyces israelli cause
Periodontal disease leading to “Lumpy Jaw”
• Foul-smelling, draining sulfur granules
• Can form slow granulomatous abscesses in any tissue
Nocardia asteroides
• Partially Acid-Fast • Branching Filamentous Bacteria • Aerobic • Transmission: ✓ via inhalation (lung, systemic) ✓ skin cuts (cutaneous)
Mycobacterium tuberculosis (TB)
- Transmission through air droplets
- thick lipid cell wall
- Bacili
How can TB be controlled
Require cell-mediated immunity to be controlled (CD4+ Th1)
Mycobacterium leprae (Leprosy)
- Obligate intracellular bacteria
* Replicates in macrophages and nerve cells
Mycobacterium marinum
- Found in bodies of fresh or saltwater globally
- exposure to the bacteria through a small cut or skin scrape
Acid-Fast Mycolic Cell Wall -Nocardia and Mycobacterium species
-Mycolic acids form a thick lipid
waxy layer that limits nutrient
uptake and results in a slow
growth rate
What does the mycolic acid cell wall help bacteria with
• interferes with normal Gram staining methods • protects the bacteria from reactive oxygen species • confers resistance to βlactams
Mycoplasma and Ureaplasma
- Pleomorphic bacteria
* Lack cell wall (protects the bacteria from antibiotics )
M. pneumoniae
which is an important cause of atypical
pneumonia and other respiratory disorders. Associated
with a dry persistent cough over weeks
M. genitalium
, which is believed to be involved in pelvic
inflammatory disease
Chlamydia spp.
• Obligate intracellular
• Lack peptidoglycan
-• Depend on host cell for ATP and NAD
Chlamydia trachomatis (Trachoma)
✓Infectious disease that affect the eyes
✓STI
• Chlamydia pneumoniae (Pneumonia)
✓Respiratory track infections including atypical
pneumonia
• Chlamydia psittaci (Psittacosis)
Zoonotic respiratory disease from birds that can
cause atypical pneumonia
✓Elementary body
EB
infectious form of chlamydia during the life cycle
✓Reticulate body
(RB) :
replicative
form of chlamydia during the life cycle
During a pap smear screening what would one see if the patient had chlamydia
Intracytoplasmic
inclusions (vacuoles)
showing elementary
bodies
Rickettsia spp
- Obligate intracellular
- Pleomorphic bacteria
- Transmitted by arthropod bite
Rickettsia rickettsii symptoms
High fever and lymphadenopathy is common
• The endovasculitis of R. rickettsii causes a petechial rash including
palms and soles, encephalitic signs, and gangrene of skin and
tissues
