30 Bacterial Infections of the LRT 3 Flashcards
mycobacteria description
weakly gram positive, acid fast rods
structures unique to mycobacteria
arabinogalactan
lipoarabinomannin
mycolic acids
etiology of tuberculosis
mycobacterium tuberculosis
reservoirs of tb
only humans
transmission of tb
respiratory droplets
tb states
primary
active
latent
reactivation
primary tb (usually asymptomatic) leads to…
- clearance
- active tb in immunocompromised individuals
- latent tb in most individuals
miliary tb or extrapulmonary tb
disseminated tb infection (granuloma formation outside of the lungs)
- gradual onset
- fatigue, weight loss, weakness, fever, night sweats, chest pain, and dyspnea
- couph with scan sputum
active tb
ghon focus v. ghon complex
focus= lung lesion complex= lung lesion and calcification seen in an affected hilar lymph
most common sight of tb infiltration
apical posterior segment of the upper lobes of both lungs
intradermal injection of purifed protein derivatives PPD
tuberculin skin test (mantoux)
-PPDs are prtns derived from the Mtb cell envelope
BCG vaccinated ppl
- not in the US
- people will test positive for tb
tb test for people with BCG vaccination
IFNgamma release assay
Ziehl-Neelsen or Kinyoun stains
- acid fast staining
- because of lipid rich cell wall
- confirms mycobacteria but not myco tb
treatment of tb
- isoniazid, ethambutol, pyrazinamide and rifampin
for 2 months - 26 months of isoniazid and rifampin
how does isonizid work?
-inhibits mycolic acid synthesis, hepatotoxicity. adverse reactions
- complex of several mycobacteria
- pulmonary infection resembling TB in immunocompromised patients or with lung disease
mycobacterium avium-intracellulare
chronic granulomatous pulmonary disease, seen in COPD
mycobacterium kansasii
characteristics of HiB
gram negative
coccobacilli
-requires NAD and hemin for growth (chocolate agar)
most pathogenic and dangerous serotype of hemophilus flu.
strain B
- has polysaccharide capsule of polyribosylribitol phosphate PRP
transmission of HiB
respiratory droplets or direct contact with respiratory secretions
virulence factors of HiB
- LPS/endotoxin
- IgA protease
- PRP capsule in typed strains
treatment for severe HiB infections
cephalosporin
