Monthly Archives: January 2016

“Media Savvy”

The Science of Microbiology, ,

Enterobacter_cloacae_01

For the trainee or new scientist starting in a bacteriology laboratory, knowledge of the media used in the workplace is a useful starting point in getting to grips with the job. For those more “experienced” scientists and technicians, an occasional revision of media knowledge is well worthwhile every now and again. I am not usually one to advocate learning a lot of factual knowledge, but I do recommend some basic reading around media types.

It is good to have an idea of the different types of media used in the laboratory, including solid (plates, slopes) and liquid media, and the different media used both for diagnostic and storage purposes.

For selective media, it is good to know what types of organisms grow on which plates, and why this happens according to the constituents/recipe of the agar.

The competent bacteriology scientist will know which media are required for different sample types and what organisms grow on which media.

The good bacteriology scientist will not just be able to do the above but also explain why certain media  are used for certain sample types.

The excellent (and innovative) bacteriology scientist will also be able (and not afraid) to make the suggestion “What is the point of using this media type A for this sample type B. It is not offering us anything extra over and above the other plates we are setting up.” or alternatively “We could add this media X for this particular sample type Y to improve our chances of isolating micro-organism Z.”

Suggestions don’t always work, often for reasons which may not be immediately apparent, but all staff should be given the opportunity and forum to make such suggestions, as opposed to settling passively for the Status Quo.

Michael

Click here for some basic MCQs on culture media.

Click here for a 5 min overview on media types.

 

 

 

“Cutting off the fat whilst keeping the flesh”

Confessions of a Microbiologist, ,

RawBacon

Reducing inappropriate or unnecessary testing is generally a good idea. Not only does it free up finances which can then be used on other more useful tests, it also improves the positive predictive value of the test in question by increasing the prevalence in the tested population.

But how exactly do you reduce inappropriate testing? Well you can look at guidelines from other centres or research papers published in journals. But in my opinion the best evidence to support reducing inappropriate or unnecessary testing is to collect your own localised data. This is particularly the case if you want to reduce unnecessary testing by introducing specific testing criteria based on certain patient or laboratory parameters.

For example if you want to restrict Hepatitis A testing to those patients with a significant ALT increase, then you need to look at the range of ALT values for all your patients with a genuine positive Hepatitis A result.

If you want to restrict Trichomonas testing to all those patients under a certain age, then you need to examine the age related prevalence rates for Trichomonas in your particular population.

The risk with cutting off the fat however is that you always risk cutting off a little bit of the flesh, i.e. you may miss the occasional positive where the patient has fallen outside the pre-determined testing criteria for that particular infection.

The key is in deciding whether the criteria or the cut-off level for testing that you have set are acceptable, and to do this you need to take into account as a minimum the severity of disease, the consequences of a missed diagnosis, the opportunity/potential to make the diagnosis at a later date. This is why you would never dream of restricting testing for syphilis in community age groups over a certain age, just because the prevalence in this cohort is so low. Because if you miss the diagnosis of syphilis the consequences could be a lot worse than if you missed a trichomonas infection…..

But possibly the most important factor to take into account when trying to adopt selective testing criteria is to consult with and gain approval from requestors, and in particular specialists in that particular area of testing. Thus it is a good idea to have good working relationships with the Infectious Diseases department and for that matter all your other users as well.

The requestors generally understand the situation. they will often be budget holders in their particular area/institution and understand exactly what you are trying to achieve. If you are reasonable, rational and communicative, only rarely will they stand in the way of what you are trying to achieve.

And the flesh and fat analogy works well in my opinion. If you try to cut off too much fat, then you will start removing the flesh as well, and you will only end up hurting the patient….

Michael

 

“The Idea Factory”

Confessions of a Microbiologist, ,

Bright_idea_-_using_cfl_light_bulbWith increasing commoditisation and centralisation, maybe our microbiology laboratories are becoming more like factories…, but idea factories? Where does that concept come from? Maybe a more apt term for a microbiology lab would be an “idea incubator”.

Microbiology laboratories, and the staff that work in them should not just be processing and producing quality test results, they should always be thinking of and producing ideas as to how things could be done better.

I’ve come up with a few (thousand) ideas in my time. It is important to remember however that only a small proportion of initial ideas ever come to fruition, regardless of who comes up with them. Some get blown out of the water within seconds, and rightly so (That’s ok, there is no shame in that whatsoever). For others it takes a little while to realise that this particular idea just isn’t going to cut it. Other ideas that are subsequently worked on change out of all recognition from the original concept.

And finally a few ideas actually succeed, which makes it all worthwhile.

Microbiology laboratories should facilitate the production of ideas, using forums such as web pages, notebooks,  performance reviews or (brainstorming) meetings to allow staff to have their say. Often the best ideas come from the people who perform the tests as opposed to office based managers, so anything that encourages suggestions from the benches has to embraced…..

With the Kiestra TLA and all its resultant potential going live soon in the laboratory I work in, I hope the lab will become a real breeding ground of innovation.

There is no such thing as a bad idea, any idea is better than none at all.

Michael