Moraxella catarrhalis

And so to remind the audience about what are those common...

CAP or HAP pathogens, we are looking at the Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, MSSA, which is the methicillin-sensitive Streptococcus aureus, or our atypicals like the Legionella, Chlamydia, and Mycoplasma.

And then if it's more of a hospital-acquired picture in terms of patients with nosocomial risk factors, we can still see the community pathogens, but we're also going to see things like MRSA, so methicillin-resistant staph aureus, pseudomonas, a bunch of other gram-negatives that like to be resistant to a lot of stuff, so like citrobacter, interbacter, And then we can also see kind of your more basic gram-negatives like E. coli and Klebsiella, but they can also develop resistance patterns and become things like multidrug-resistant, like carbapenemase-resistant enterobacteriaceae or ESBL-producing bacteria that degrade some of our more common antibiotics, and we need to use broader spectrum gram-negative coverage for those patients.

So with us understanding the bacteriology a little bit better, what are some of the guideline recommendations of how we should go about treating it?

Acute otitis media most commonly follows eustachian tube dysfunction following a viral infection, allowing bacteria to proliferate within the middle ear.

The major organisms here are strep pneumo, nontypable Haemophilus influenzae, and Moraxella catarrhalis.

High dose amoxicillin is first line for most children because it provides strong coverage against pneumococcus, is relatively narrow, is well tolerated, and reaches good concentrations within the middle ear.

Next up, let's imagine that same child presents again with otitis media after having just been treated with amoxicillin two weeks ago.