Enterococcus in Blood Cultures Remember 123

I have recently been in the situation of dealing with a number of blood cultures which have grown the bacteria Enterococcus sp. Whilst not a particularly exciting bacteria, its presence in blood cultures should always be taken seriously. One particular patient had Enterococcus faecalis in 3 sets of blood cultures and was being treated for pneumonia on the basis of a fever and a few crackles in his chest. I went to the ward to review the patient and although a junior later commented that “you always come up with an amazing diagnosis!” it was “The Microbiology” which led to the correct answer, but I took the compliment anyway!

So how did I know this Enterococcus sp. was important? The correct question is, “what are the possible explanations for the presence of an Enterococcus in this patient’s blood culture?”

1. Intra-abdominal infection with a mixture of bacteria. The Enterococcus is inherently resistant and able to
   break through the usual antibiotic choice therefore it is often the only micro-organism that grows in the culture e.g. diverticulitis, cholangitis, peritonitis
2. Intra-vascular infection where the Enterococcus is present at all times in the blood because it has adhered to some other structure e.g. IV device related infection or infective endocarditis
3. Translocation across the bowel wall due to a bowel lesion e.g. malignancy, WARNING the patient may not be showing any other features of an infection such as a fever. Translocation can be the route which leads to the bacteria adhering to another structure, as in No.2 above.

There are almost no other situations when you might see Enterococcus in a blood culture THEREFORE IT IS ALWAYS IMPORTANT to work out what is wrong with these patients as it significantly impacts their management.

1. Intra-abdominal infections may require surgical intervention to drain the biliary tree or an abscess or
   repair a perforated abdominal viscus.
2. Infected IV devices need to be removed, if infective endocarditis is present, it will need prolonged courses of IV antibiotics (up to 6 weeks)
3. Early bowel malignancy may be cured with surgery alone

I teach students to ask “why”, like a small child, until there are only obvious answers remaining...yes sometimes you cannot get an answer to a vague history when tests are inconclusive...we’ve all been there! But when there is a result, there will be a reason...you just haven’t unravelled
the pieces to reveal the full picture. Keep asking “Why?”
“Why would that be there? ...Where should that be? ...Why
is it there?” These dilemmas should be what inspire doctors to make great diagnoses. Embrace it. Keep asking “Why?"

This patient had a history of weight loss and fever, and on close examination had splinter haemorrhages, splenomegaly and a loud heart murmur. It was clear they had infective endocarditis but their colonoscopy showed an underlying Dukes B bowel malignancy. The patient did very well; he recovered from both his infection and the operation, which proved curative for his cancer. So don’t let the mundane drag you down, always keep asking “Why?”

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