W4 - pt1 respiratory infect 2 Flashcards
bronchitis
- Rx?
doesn’t usually need antibiotics
unless pt immunocompromised
bronchitis
- protracted due to
1.
2.
- Bordetella pertussis
2. mycoplasma pneumoniae
bronchitis
- need to watch out for?
acute EXACERBATIONS OF CHRONIC BRONCHITIS
- need lab Dx (determin SUSCEPTIBILITY of BACTERIAL AGENT
bronchitis
- main sign of ‘acute exacerbation of chronic bronchitis’?
- Rx?
INCR in EXUDATE (amount of SPUTUM)
***in this case treat with ANTIBIOTICS, otherwise poss further complications
***also maybe fever and incr coughing
big problem with chronic brochitis?
chronic coughting causes DAMAGE
>as pt become older more likely to become EMPHYSEMIC
acute community acquired PNEUMONIA
- often caused by?
- strep pneumoniae
acute community acquired PNEUMONIA
- blood film shows?
- raised WBC COUNT
“left shift” =band polymorphs (young PM)
exam Q
- is sputum ALWAYS produced in pneumonia
NO
- normally yes bec bacterial most common cause (strep pneumoniae)
BUT
- if due to VIRUS then no pus
- pt IMMUNOCOMPROMISED (eg. cancer or leukemia) pt unable to prod immune cells that make up the pus in a bacterial pneumonia
exam Q
capsules are _ tf more likely to cause _
capsules are ANTI-PHAGOCYTIC tf more likely to cause PNEUMONIA
(streptococcal pneumoniae)
strep = chain
short chain in capsule
pathomechanism
- streptococcal pneumoniae?
why is the sputum often bloodstained?
> capsules invade ALVEOLAR TISSUE
multiply
prod PNEUMOLYSIN
>destroys host cell
**lung alveolar lining only ONE CELL thick! > they break down >bld into lung>coughing up bld
**>can spread to bloodstream and c. SEPTICAEMIA
Envelope:
- (Science: virology) LIPOPROTEIN OUTER LAYER of some viruses derived from plasma membrane of the host cell.
- (Science: microbiology) The PLASMA MEMBRANE and CELL WALL complex of a bacterium.Oct 3, 2005
***BACTERIAL CELL ENVELOPES fall into two major categories: a GRAM-POSITIVEtype and a GRAM-NEGATIVE type, distinguished by Gram staining.
gram positive
vs
gram negative
Gram-positive bacteria
- cell membrane
- peptidoglycan (thick layer 50-90%)
- thick mesh-like cell wall made of peptidoglycan
- stained PURPLE by CRYSTAL VIOLET
Gram-negative bacteria (destroyed by dry)
- cell membrane
- peptidoglycan (thin layer)
- lipoprotein
- outer memb of lipopolysaccharide (LPS = endotoxin)
- thinner layer peptidoglycan (10% of cell envelope), so do not retain the purple stain and are
- counter-stained PINK by SAFRANIN.
non-enveloped virus
vs
enveoloped virus
Non-enveloped viruses
are composed of CAPSID PROTEIN and NUCLEIC ACID (DNA or RNA)
= nucleocapsid
(which constitute an infectious unit = virion)
**heat-resistant
**protein capsid less susceptible to environmental conditions (lipid solvents, pH, temperature…)
whereas enveloped viruses are composed of an NUCLEOCAPSID plus an ENVELOPE (and ENVELOPE PROTEINS)
***heat-sensitive
eg. non enveloped virus (naked viruses)
norovirus
parvovirus
HAV (hep A)
HEV (hep E)
eg enveloped virus
influenza virus
HIV
HBV (hep B)
HSV (herpes simplex)
viral envelopes are made of?
and function to?
- host cell memb (phospholipids and proteins)
- some include viral glycoproteins
- help viruses avoid the host immune system
> have great adaptability
can change in short time in order to evade immune system
>can cause persistent infections
***once envelope is LYSED virus loses funtional receptors > not able to infect cells
