​​​We are so pleased you all enjoy reading the bug blogs and are delighted to announce that we have been ranked 3rd in the "top 25 Microbiology blogs". Your continued support is much appreciated.

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Good luck with the puzzle and Merry Christmas. See you in the New Year!

​A previously fit and well child is seen in outpatient clinic by the Paediatricians, as he has now developed tics. As if to emphasise the point the boy suddenly jerks as though ”shocked” and then bursts into tears. His parents are beside themselves with worry. Whilst planning how to manage the child’s neurological symptoms the story comes out that he had a bit of a sore throat a couple of weeks earlier (not an uncommon complaint in 5 year olds). The Paediatrician devises a management plan for the child’s tics but takes a throat swab “just in case” the child has tonsillitis.
 
Later that day, whilst discussing another patient with the Microbiologist, the Paediatrician happens to mention the boy with tics and a sore throat. “I wonder if he has PANDAS?” the Microbiologist says. “What have giant pandas got to do with it?” asks the Paediatrician. “Not giant pandas, but PANDAS - Paediatric Autoimmune Neuropsychiatric Disorder associated with group A beta-haemolytic Streptococci” explains the Microbiologist. “What are you talking about?!” exclaims the Paediatrician with a weary smile… Ah… let me expand…

​An elderly diabetic man presents to hospital with a fever, tachycardia and hypotension. He is septic and so blood cultures are taken and he is started on IV Piptazobactam as per the hospitals empirical guidelines for sepsis. There is no obvious focus and therefore source control (e.g. draining of an abscess) at this time is not possible.
 
The next day his blood cultures signal positive and a beta-haemolytic streptococcus is isolated. What does this mean? What is the significance?
 
Does the terminology around beta-haemolytic streptococci confuse you? It did me when I was a student and junior doctor; I couldn’t understand why beta-haemolytic streptococcus wasn’t the Group B streptococcus! They both have a “B” in them just one is the Latin letter while the other is Greek; surely they are the same thing? Well no, they’re not so how did I eventually get to grips with them.

Previously I blogged about the use of antibiotics in pancreatitis and I mentioned procalcitonin as an exciting new marker of infection. I have little experience of this laboratory test but have heard many others talk about how useful it is. But what is it? What is it useful for? Can it help in the diagnosis and management of infection?
 
What is procalcitonin?
Procalcitonin (PCT) is a protein produced by the thyroid, lungs and intestine in response to inflammation, especially when the inflammation is caused by bacterial infection. In contrast, levels of PCT do not increase much when inflammation is caused by viruses or most non-infectious causes. Levels increase quickly (within 2-4 hours) and have a half-life of 24-36 hours. It is suggested (by the manufacturers of the PCT assay machines) that PCT can therefore be used to identify septic patients and predict who is at risk of developing severe sepsis. The amount of PCT is said to be related to the amount of inflammation therefore in theory the level of PCT can also be used to monitor response to treatment; a decrease in PCT corresponding to a favourable response to treatment.