Staphylococcus aureus

Today we're talking about an organism that honestly probably needs very little introduction for anyone practicing in medicine, but one that continues to cause an incredible amount of diagnostic and therapeutic trouble.

We're talking about Staphylococcus aureus.

And joining me today is Catherine Easterwood, a family nurse practitioner in the Department of Infectious Disease at St. Jude Children's Research Hospital.

She earned her Bachelor of Science in Nursing from the University of Texas at Martin in 2009 and her Master of Science in Nursing as a family nurse practitioner from the University of Memphis in 2012.

I think this is a great organism to talk about in the podcast because it's so prevalent and yet continues to surprise us.

For the clinicians listening, can we go back to the basics a little bit? What exactly makes Staph aureus so virulent, so successful at creating infections?

Yeah, Cystaphylococcus aureus is a gram-positive caucus that typically appears in clusters on the culture gram stains.

It is coagulase positive, meaning that it produces an enzyme, coagulase, which makes the plasma clot.

And that's been shown to be very beneficial in priming the immune system as well.

So there's a microbe that commonly lives in the nose called Staphylococcus aureus, and it often causes little sores around the nose, things we call impetigo.

commonly called school sores in Australia.

And there's some compelling research that supplementing with bacillus subtilis actually can reduce, significantly reduce these microbes in the nose and in the gut.

So a bunch of guys hanging out, and often it is guys, I hate to say, the Delphi consensus, like a bunch of guys hanging out in a room, breathing in the vapors, saying, what do we all agree on? Whether a clinical response-tailored antibiotic management strategy can shorten treatment duration without compromising safety is unclear, right? So we're going to look at that.

So these are the results of an international, open-label, randomized trial where they assigned adults in stable condition with infective endocarditis caused by Staph aureus, Enterococcus faecalis, or Streptococcus species to receive either response-tailored or standard-duration antibiotic therapy.

Before randomization, all the patients received at least the pre-specified two to four weeks of therapy met criteria for clinical stabilization.

After randomization, patients in the tailored therapy group discontinued antibiotics or And those in the standard therapy group, continued standard therapy, total duration four to six weeks.

Haemophilus influenzae type B used to be the most common cause, but it's much less frequent now after the Hib vaccine.

The most common microbes in the current era are gram-positive cocci, like Staphylococcus aureus and Streptococcal species.

There are gram-negative and anaerobic bacteria that can be involved.

MRSA accounts for around 70% of all Staphylococcal cases.

Complications include primary viral pneumonia severe but uncommon.

Secondary bacterial pneumonia, the most common serious complication, often caused by Staphylococcus aureus, Streptococcus pneumoniae or Haemophilus influenzae, Myocarditis, Encephalitis.

Reyes syndrome in children given aspirin during influenza or varicella, this is why aspirin is contraindicated in children under 16.

Exacerbation of chronic conditions asthma, COPD, heart failure, In most cases, diagnosis is clinical during a known outbreak.