Monthly Archives: November 2016



Clinical Microbiology, like many areas of medical practice these days is becoming increasingly dominated by guidelines. This is generally a good thing. They are usually evidence based where possible, and written by people who know (or should know) what they are doing.

However guidelines are not perfect for the following reasons:

  • They are generic:- Not every case can be covered in guidelines, so generally only the most common scenarios are covered. More uncommon diseases/presentations are often free of guideline interference!
  • They are conservative:- Guidelines are generally not radical in nature. If a guideline is followed and things subsequently go pear-shaped then the authors will not want anything too radical within the guideline in case there are legal implications. This is especially true for guidelines which rely on expert opinion. If you feel your patient needs a radical solution/treatment, then guidelines are not necessarily the best place to look.
  • They are cohort specific:- Guidelines usually originate from specific areas, and are often based on specific patient cohorts, so they may not apply to your particular patient cohort.
  • There may be conflicts of interest:- Guidelines may be written with other agendas at stake in addition to patient care. Cost, acceptability by the public and political agendas may all contribute to producing guidelines that are sub-optimal from a patient perspective.

As Healthcare professionals we are coming under increasing pressure to follow guidelines. However too much reliance on guidelines might stop us considering patients as individuals, with specific problems and specific solutions.

Is it ok not to follow guidelines sometimes?

In certain circumstances yes, absolutely, but I strongly believe that one must understand the rules fully in order to break them properly.

“Learn the rules like a pro, so you can break them like an artist”   (Pablo Picasso)


Please note my tech savvy son is setting up a Microbiology Matters YouTube channel for me so I can record some irreverent microbiology videos! Will keep you posted on this over the next couple of weeks…


“Too much knowledge…”


A little bit of knowledge can be a bad thing. So can too much…

The acronym  ESCHAPPM ( or something similar) will be familiar to most microbiologists. (a similar acronym SPICE, is sometimes used instead)

  • Enterobacter spp.
  • Serratia spp.
  • Citrobacter freundii
  • Hafnia spp.
  • Aeromonas spp.
  • Proteus spp.
  • Providencia spp.
  • Morganella morganii

Because we are clever microbiologists, we know this group of organisms may have inducible beta-lactamase activity, and we advise the clinicians of this, often provoking a reflex switch in anti-microbial therapy to carbapenems. Not only clinicians, but there are plenty of ID physicians who make this automatic transfer to carbapenems the moment the word ESCHAPPM is mentioned, my hospital included.

The thing is however, do all patients with infections by an ESCHAPPM organism require a carbapenem?

Almost certainly not…

If we use a carbapenem for every infection due to one of these organisms, then this amounts to a significant amount of carbapenems. This is therefore an important an important antimicrobial stewardship issue. We are supposed to be trying to decrease the use of broad spectrum antibiotics, not increase them.

But we have read the textbooks, and we are clever…

And yet, if we look at the literature, there is very little evidence to support the theoretical dangers of using a beta-lactam in such patients. In fact, there are several small studies out there that support the non-inferiority of beta-lactams in such patients, particularly in non-life threatening illnesses.

Not to mention there are other options out there, fluoroquinolones, sulphonamides, etc.

We are simply scared.

Here is what I generally do (rightly or wrongly):

  • In a patient with bacteraemia due to an ESCHAPPM organism, as long as they are clinically improving I am happy to continue therapy based on the phenotypic susceptibility results.
  • In patients with UTIs due to ESCHAPPM organisms, even if in hospital, I feel no need  whatsoever to move to carbapenems.
  • I reserve carbapenem use in “ESCHAPPM” patients to bacteraemic patients who are getting worse, and also for patients with chronic infections, e.g. prosthetic joint infection, on the rationale that the longer the treatment, the more chance you have of getting clinically relevant inducible beta-lactamase activity.

We need to take a more pragmatic approach to ESCHAPPM organisms and their treatment. We also need larger scale trials so we can be more confident in our decisions and adopt such approaches into guidelines.

and we need to be brave…