welcome to another MedCram board vitals question this question comes from
our family nurse practitioner banks and the question is what are the three
bacterial organisms that are the most common causes of agents of CAP or
community acquired pneumonia in adults first choice is a and that's Klebsiella
pneumoniae Pseudomonas aeruginosa and Hamas influenza B is mycoplasma
pneumoniae chlamydia pneumonia and streptococcal pneumonia which is the
correct answer C is Hamas influenza chlamydia pneumonia and Moraxella
catarrhalis and D is Legionella species chlamydia pneumonia and mycoplasma
pneumoniae so which one is the right answer in this case it's B but the
question is is why is it the right answer so let's review that so I wanted
to go over these eight different bacteria and their characteristics so
the first thing you should know is that streptococcal pneumonia is actually the
most common bacterial cause for pneumonia so right off the bat that is
the biggest thing you should know you should know that streptococcal pneumonia
is the most common bacterial cause for pneumonia and if you'll remember on a
Gram stain they're going to look like gram positive cocci in pairs so that's
the thing to look for is you'll see those in pairs like that
now the next one is Hamas influenza homophonous influenza is also seen in
community acquired pneumonia very commonly but not as commonly a strep
pneumo it's also seen in COPD so make sure you're aware of that as well
Klebsiella pneumoniae not as commonly seen in pneumonia it's not a common
cause of it but it is associated with alcohol consumption these two right here
chlamydia pneumonia and mycoplasma pneumoniae are bacteria that do cause
pneumonia but they cause a different clinical syndrome
whereas that these ones that we've talked about
here cause a typical type of pneumonia these are very commonly called an
atypical now be aware that atypical pneumonia and typical pneumonia are
still under the umbrella of community acquired pneumonia which is what the
question was dealing with so there is typical and there's a typical so be
aware of that and a typical clearly are these two right here they are also very
commonly seen in cap even though they are a typical atypical means that
they're gonna have this type of walking pneumonia it doesn't present typically
typical pneumonia is fever white count infiltrate feeling short of breath
things of that nature now for the next one I'm gonna use the color green
because Pseudomonas is classically green in color so if you see a patient with
green sputum it doesn't necessarily mean they have Pseudomonas aeruginosa but you
may want to think about it especially if they've got lung disease chronic lung
disease like COPD bronchiectasis especially cystic fibrosis this is
classic cystic fibrosis now the reason why you should know about Pseudomonas
aeruginosa even though it's not one of those bacteria that's commonly found in
cap is because of antibiotic resistance and we'll just touch on that briefly but
first I want you to remember that Pseudomonas aeruginosa is typically not
seen in community acquired pneumonia because these are seen in more
hospital-acquired or healthcare acquired pneumonia so it's not one of the most
common ones for cap so what do we typically treat suna mones originally
with well there's a number of different of antibiotics for Pseudomonas
aeruginosa but you can think about the fluoroquinolones you can think about the
carbapenems you can think about the amino glycosides all of those cover them
there are some third and fourth and fifth actually generation cephalosporins
that cover it like ceftazidime cefepime and azure boxa which is a more recent
generation cephalosporin and then you can get into some of the other ones
for instance aztreonam which is a mono lactam which can cover Pseudomonas
there's the carbon atoms as we talked about like meropenem there are the
fluoroquinolones as we mentioned those are the only ones that are available
orally the key though here is Pseudomonas aeruginosa is a very
specific bacteria that you've got to know a lot about not typically seen in
cap Moraxella catarrhalis kind of known as MCAT for those of you who have to
take the MCAT MCAT or Alice is typically seen in acute otitis media it can also
be seen in COPD as well and then finally the last one here is Legionella
Legionella we would not consider part of cap because it's typically seen in
outbreaks so think of this in outbreaks if there's an epidemic okay that would
be on a cruise ship or air conditioning or in a hotel that's what you want to
think about Legionella not in cap so what are ones that we see in cap we see
streptococcal pneumonia in cap we see Hamas influenza in cap we see these
atypicals in cap cap stands for community acquired pneumonia
this is chlamydia pneumonia and this is mycoplasma pneumoniae so we're back with
the question now and the question again is which are the three bacterial
organisms that are the most common causes of agents of CAP well if you just
go with the very first thing that we said which was that streptococcal
pneumonia is the most common the only one of these answer choices that has
streptococcal pneumonia in it is correct chlamydia pneumonia and mycoplasma
pneumoniae are the other two and therefore B is the correct answer
Klebsiella pneumoniae is seen in patients who drink a lot of alcohol not
necessarily cap we talked about that Pseudomonas aeruginosa is not seen in
cap and hemolysis influenza is seen in cap by the way influenza here this is
not the flu virus this is a bacteria just so you're aware see Hamas influenza
yes chlamydia pneumonia yes and catalyst no that is not seen
typically in or commonly in community-acquired pneumonia for D
Legionella species we've already said that this is not part of the community
acquired pneumonia Kadri of bacteria this is seen in
outbreaks this is seen spread by water air conditioners things of that nature
the other two though are part of cap and that's Klebsiella pneumoniae and
mycoplasma pneumoniae thanks for joining us