Monthly Archives: November 2015

“Hearing aids”


I have never found ear swabs a very satisfactory microbiological sample, the outer ear canal usually being filled with all manner of debris and micro-organisms regardless of whether an infection is present or not. (Try processing a swab from your own ear!)

In addition it is often difficult to tell from the request form whether the swab has been taken from the external part of the ear or right inside the canal.

I doubt whether the results of many ear swabs ever affect the clinical outcome of the patient.

Nevertheless I have a few rules for ear swabs, to help both the scientists and myself make the results generated as sensible as possible.

  • If respiratory organisms (H. influenzae, S.pneumoniae, M. catarrhalis) isolated from a toddler ear swab, it is likely to be an otitis media with a perforation. (there is also the possibility that the organism has got into the ear from the mouth via the finger of the toddler). I tend to do susceptibilities on such isolates on the rationale that a systemic antibiotic may be indicated for recalcitrant cases.
  • If Staphylococcus aureus and Streptococcus pyogenes are isolated together from an “ear swab” then the chances are it is an impetiginous lesion. Therefore I do susceptibilities on the staphylococcus (but not the S. pyogenes, see “Excuses”)
  • Rule of three. If three or more organisms are isolated from an ear swab then you are essentially wasting your time identifying every member of the zoo. What help is this going to be to the clinicians. Would simply report as “Mixed flora” or “Mixed Coliforms.”
  • With the exception of the first two points above I would hardly ever perform susceptibilities on isolates from ear swabs. I am not aware of any evidence that doing this improves patient outcomes. The one exception to this would be where there is clinical details of “mastoiditis”. In this clinical scenario, if there is a pure or dominant organism, or a Pseudomonas aeruginosa, it should be worked up.

Ear swabs are over-worked, over processed and over-interpreted in clinical microbiology laboratories all over the world. 

The results of ear swabs can sometimes help with clarifying the aetiology of the ear symptoms, as described above. However they do little to affect the management of the patient, and we should bear this in mind when processing them…..


“Is it or isn’t it?”

There are many amongst us who are unfortunate enough to be required to read Gram stains as part of our work, and usually lots of them. There will inevitably be occasion when one comes across a stain where it is uncertain whether bacteria are present or not, or whether it is just debris/stain deposit etc. And it usually doesn’t matter how much you look at it! You can scan the slide ad infinitum, then ask your colleague for their opinion, which usually turns out to be identical to yours…. “I’m not sure”

This happens to all of us regardless of our expertise or experience.

The first thing to do of course is to repeat the Gram stain, in the hope that it gives a clearer picture. However if you get a similar picture on repeat testing, how do you report it?

In superficial wound swabs it is of course of minor importance, which makes you wonder why we ever bother doing Gram stains on such samples (we are very selective now in this respect at my laboratory), but occasionally you will come across such a stain in a sterile site sample, such as a CSF or a joint aspirate.

My experience with such results is that when the Gram stain finding is uncertain like this, then it is rarely of help to the clinician, and does little to improve the patient’s outcome. In fact, on occasion, when an uncertain finding of bacteria are reported on Gram stains from joint aspirates, it can occasionally lead to an unnecessary procedure/operation….. I have seen this happen from time to time.

Depending on the level of uncertainty, one could telephone the clinician to relay this uncertainty. “I have had a look at the Gram stain and there might be a few things there which look like Gram positive cocci, but I cannot be certain….” The issue with this however is that uncertainty often becomes certainty by “Chinese Whispers”.

If it is unclear whether bacteria are present on the Gram stain, then depending on the clinical scenario, I think there is a very good argument for not reporting anything at all, as opposed to reporting something which is potentially misleading.

What do you think?


“The Clock Watching Microbiologist”

Time management can be difficult in microbiology. There is so much going on, and so much to know. It can be easy to get lost in time warps and suddenly find that yet another Christmas is not far away! I wouldn’t say I am the best in the world at time management, nor do I always practice what I preach, but here are a few things I try to adhere to in order to free up a bit of time for myself. I am essentially quite a lazy person, so I put in a fair bit of time facilitating this personality trait!

Be very selective re voluntary work: A lot of people are too busy simply because they take on work that they strictly do not need to do, particularly from sources external to their core work/job. I try and only take on work where I am very interested in the issue or which would be really beneficial to me. The rest gets politely declined.

Pick and choose your policy reviews: This is not dissimilar to the above. If you are on any committees related to your work you will be asked, with relative frequency, to review some policy or other. I would always ask myself “Am I the person on this committee who is the most suited/appropriate for reviewing this document? If not, I don’t. I also believe that if you are going to take the time to review a policy then you must always feedback and try and improve on what is there already. Otherwise it is wasted time.

Only check emails 3-4 times per day: Morning, lunchtime and late afternoon. Switch your mailbox off completely in between. Get rid of email alerts completely. Someone else’s important is not your urgent. I also believe in the mantra that the more emails you send, the more you will receive, and thus the more work you will end up with.

Zero inbox policy: This works very well for me. I go through each of my emails and either delete, file in a folder or put into my outlook calendar and schedule whatever time is needed to do the work from the email. My inbox has almost always only single figure number of emails present, much less stressful…. I have seen too many people while away hours and days trawling through historical emails in their inbox. It’s a bad habit to get into.

Multiple breaks: I tend to work hard for half an hour and then take 5-10 minutes break, throughout the day with the exception of lunchtime where I get out of the lab/hospital for half an hour. I hardly ever work late.

Delegate: I try and delegate work wherever possible, in a diplomatic manner, and without pushing my luck too much! This is one I sometimes find difficult, but I have improved a bit over the years.

Prioritise: I always set myself a goal of doing one thing per day related to my own goals (not other peoples), which I then prioritise as far as possible over everything else. Otherwise you end up following other people’s agendas (for them), not your own.

At the end of the day it is not time management I have a big problem with, it is energy management. I do a fair bit of stuff outside of work, looking after 5 children, training for ultramarathons, learning French etc. Sure I often have a free hour or two in the evenings, but usually the only thing I am fit for is drinking beer and watching TV!