Lecture 6 Flashcards
What pathogens have respiratory transmission?
Mycobacterium Mycoplasma Corynebacterium Bordetella pertussis H. influenzae Legionella Pneumophila
How fast do mycobacterium grow?
Very slow
What confers virulence to mycobacterium?
Cord factor
What confers acid fastness to mycobacterium
Mycolic acid
M. Tuberculosis CP
Fatigue
Fever
Weight loss
Cough with bloody sputum
What are the three possible outcomes of M. tuberculosis infection
Heal
Necrosis
From productive lesion (granuloma)
Mycolic acid function
Prevent attach by lysozyme and complement
What is lipoarabinomannan (LAM) function
Stimulates cytokine production by host (TNF and IL-6 stimulate HIV)
What is a granuloma
Mycobacterium survives in macrophage
Macrophage secretes cytokines to recruit immune cells (but can’t kill)
Immune cells swarm and create a huge grouping of cells
What is the exception to aerosol spread of TB
M. bovis
What is M. tuberculosis first act?
Attach to respiratory macrophages and invade
Prevent phagolysosome fusion
M. Tuberculosis cytotoxicity?
Cord factor
What is miliary TB
Spread of TB via blood to various parts of your body
TB in your lungs spreads were?
To regional lymph nodes
What is a caseum?
A fibrous cuff in necrotic tissue that can form around TB and make it look inactive. However it can rupture and lead to reactivation.
Who is at risk for TB
Immigrants
Other infections (silicosis, emphysema, HIV)
Very old or young
Homeless or destitute
TB’s has which of the 3 I’s ?
Cytokine mediated inflammation
PPD tests for?
T cells specific for TB
Quantiferon Gold tests for?
Release of interferon-gamma
What is the gold stand for TB test?
PCR with primers for M. Tub.
What is the only way to diagnose latent vs active TB?
XRAY
Four drugs for TB?
INH
Rifampin
Pyrazinamide
Ethambutol
What are secondary drugs for resistant TB?
Fluorquinolones
Aminoglycosides
What causes leprosy?
M. Leprae
Why don’t beta-lactams work for TB?
Because of beta-lactamase blaC
M. Leprae treatment
Dapsone (sulfone) and Rifampin
What disease is found only in immunocompromised patients and has similar symptoms to TB?
M. Kansasii
What is most common nosocomial disease in HIV patients?
M. avium-intracellulare
M. avium intracellulare treatment?
Clarithromycin and ethambutol for life
What is mycoplasmas appearance on agar?
Inverted fried egg
What does Mp. pneumonia typically present as
Walking pneumonia
Tracheobronchitis
Mild fever and non-productive cough
How is Mp. pneumonia spread?
Respiratory droplets
How does Mp. pneumonia adhere?
Has a proline rich adhesion protein
Mp. pneumonia cytotoxicity?
Competes for nutrients
Produces ROS and peroxide
Does not live in a cell
What shouldn’t be given for Mp. pneumonia and why?
PCN
They don’t have cell walls
What can be given for Mp. pneumonia if the infection is bad?
Tetracycline
Erythromycin
What is the best treatment right now for MDR TB?
Meropenem and Clavulanate
What are the two main forms of leprosy?
Tuberculoid leprosy (paucibacilliary) Lepromatous leprosy (multibacilliary)
What is tuberculoid leprosy
Macular lesions
Unilateral nerve damage
What is lepromatous leprosy
Nodular lesions
Bilateral nerve death
Bone resorption
Of the 3 I’s, how does leprosy work?
Inflammation (damages nerve endings)
What are most forms of mycoplasmas?
STDs
What kind of mycoplasma can cause urethral and genital infections?
Is a normal flora
M. genitalium
Which mycoplasma can cause post-partum fever?
M. Hominis
Which mycoplasma can cause non-gonococcal urethritis in males
Ureaplasma urealyticum
How does ureaplasma urealyticum cause non-gonococcal urethritis?
Urease releases ammonia from urea which alkalinizes urine
What is the MOST common cause of non-gonococcal urethritis?
Chlamydia Trachomatis
What allows A portion of AB toxin to interact with environment?
Low pH of phagocytic vesicle causes conformational change
Describe corynebacterium diphtheriae
GramPos
Club shaped
Pleomorphic
Aerobic rod
Clinical presentation of corynebacterium diphtheriae
Cough
Sore throat
Swollen lymphnodes
Sometimes pseudomembrane in back of throat
What is the risk of corynebacterium spreading?
Toxin can spread to multiple places but most often the heart
How does corynebacterium spread?
Respiratory droplets
How does AB toxin get internalized?
B part binds to EGF-like receptor
What does A part of AB toxin bind? What does this do?
NAD
ADP-ribosylates EF-2 (this is a transcription factor so protein synthesis stops)
How does iron effect the synthesis of AB toxin?
Bacteria sense iron and only in the presence of low Fe will they produce AB toxin
If someone is diagnosed with diphtheria, what is the treament?
Large dose of equine antitoxin
PCN and erythromycin to keep bacteria count low
How does corynebacterium get AB toxin?
Beta-phage conversion
