Monthly Archives: April 2016

“Enteric flora happens…”

The Art of Microbiology,

Enteric flora (a mixture of bacteria of enteric origin) causes problems for clinicians and microbiologists alike.

The reporting of enteric flora from superficial swabs often triggers a prompt switch to a broad spectrum antibiotic by the clinicians, in order to cover all the possible bacterial species that one might find in enteric flora. I have seen this happen a few times over the past week, to the extent that I sometimes wonder whether this is the best way of reporting such a result…

The bacteria that are found in enteric flora hardly ever cause superficial wound infections (particularly in immunocompetent patients), and even when they do, the laboratory cannot possibly be of any help here because we don’t know which one in the cocktail is the culprit.

In addition one may see a laboratory report with a heavy growth of enteric flora along with a light growth of either Pseudomonas aeruginosa, Bacteroides fragilis, Candida albicans or Streptococcus agalactiae. However, enteric flora naturally contains these micro-organisms anyway, so no surprise there.

Just more unnecessary antibiotics for the patient…

A good proportion of swabs from the peri-anal area will grow enteric flora. This goes without saying, and only demonstrates the relative futility of such swabs…

What about sterile site cultures? When we see ‘enteric flora’ in such areas as peritoneal fluid or pleural fluid, we need to strongly suspect that faecal material has managed to get in there. For example a patient with a perforated appendix will have enteric flora cultured from their peritoneal fluid, the patient with an esophago-pleural fistula will have enteric flora in their pleural fluid.

This does not mean however that we have to start working up every different organism in the mixture (it is faeces after all!). Only if there is clearly a dominant organism, which can certainly happen after a period of time has elapsed under antibiotic pressure, should one consider ID and susceptibilities.

In summary we need to see enteric flora for what it is, and be brave enough to call it as such…

Michael

 

“Patient Power”

Confessions of a Microbiologist

The concept of the patient ordering a laboratory test (and receiving the result) instead of the clinician is becoming increasingly popular. It is known under several synonyms such as “Patient Directed testing”, “Patient paid testing”, “Direct Access testing”, “Patient self-requested testing”, etc., etc.

This type of testing can be argued for in terms of patient empowerment, patient privacy, cost saving for the patient, as well as convenience.

However this style of testing has never sat comfortably with me…

By taking the clinician out of the equation, there is an increased risk that the wrong tests will be requested, and equally as important, that the results produced will be misinterpreted.

Private laboratories tend not to discourage patient requested testing as it is almost always paid for by the patient themselves, and thus represents another income stream. For me however, such a practice needs to be very carefully monitored. It goes against all my medical training, and it belittles the expertise offered by the clinicians in ordering the correct tests, and correctly interpreting the results. It also removes any possibility of pre-test counselling.

And for microbiology (and infectious serology) tests, the clinician input is particularly important. For example, pre-test counselling before HIV & STD testing, the correct ordering of hepatitis serology, and the accurate interpretation of wound swab results are all clear examples amongst many of the potential pitfalls. These areas are difficult enough for professionals with years of training, never mind patients!

Patient requested testing looks as though it is here to stay, so needs to be very carefully regulated and controlled.

However good clinical practice should drive the agenda here, not patient pressure or commerce…

Michael

“Tedium”

Confessions of a Microbiologist,

One of the downsides of bigger and more centralised microbiology laboratories (and the consequent large volumes) is that you may find yourself doing the same task for prolonged periods of time.

Depending on where you work (and more and more of us work in such institutions), this might be anything from aliquotting urines, pipetting micro-titre plates, looking at Gram stains, putting up samples, plate reading, signing out results, etc, etc…

…And if you are doing repetitive tasks for a prolonged period, it can be easy to become bored and disillusioned. There is also the risk of losing concentration and making mistakes.

What is the answer?

Here are a few options:

  • A high degree of bench rotation. (even on a day to day and hour to hour basis)
  • A culture of the “quiet” benches helping the “busy” benches.
  • Frequent breaks
  • Automate what can be automated.

Whatever you do in the field of microbiology or infection, there will always be some degree of tedium in your work, but it should not be the dominant part of your work. High volume laboratories need to be extremely wary of this.

So if you are a bored microbiologist, you need to let your boss know and do something about it!

Michael