Okay, so the Bug Blog is usually about the clinical and scientific aspects of microbiology but this week I’m going to do something a bit different. Now I’m not someone who watches much TV; there was very little on that interested me over the Christmas period. However, I did watch a short TV hospital dramatization called Charité on Netflix which I thought was brilliant and something that anyone interested in microbiology would also enjoy. OK so it’s in German with English subtitles, but it is the best show I have watched in a long time! Let me explain.
“I have a 3 year old patient with an infected ulcer on their leg which is proving particularly difficult to treat” was the opening statement from the Surgeon.
“What antibiotic are you giving?” asked the Microbiologist in a surly tone, thinking this was going to be a simple case of wrong antibiotic.
“I’ve been using Co-amoxiclav, but it doesn’t seem to be getting better” was the reply.
“Have you sent any samples to the lab?”
“I swabbed the wound and the result has come back showing a Coagulase-positive Staphylococcus; I wonder if this might be Staphylococcus pseudintermedius or possibly Staphylococcus aureus” said the Surgeon.
“Staphylococcus aureus is the most common bacterium we see in this situation” answered the Microbiologist, “why do you think it might be Staphylococcus pseudintermedius?”
“In our patients Staphylococcus pseudintermedius is often grown from these types of samples…oh, I forgot to mention, I’m a Veterinary Surgeon and the 3 year old patient is a Husky” was the reply…. “I should say too that the bacterium is resistant to beta-lactams… according to the report…
Looking down the blood cultures list whilst prioritising what needed phoning out first the Microbiologist noticed a blood culture positive on day 3 with a Gram-positive bacillus in the aerobic bottle only. Normally this wouldn’t provoke much interest as most pathogens grow within 12-24 hours and most Gram-positive bacilli are skin contaminants (Corynebacterium spp. and Cutibacterium spp.). However these were unlikely in this case: Corynebacterium spp. normally grow faster than this and would be in both bottles whereas Cutibacterium spp. although anaerobes tend to grow much slower. The clinical details just said “fever” (not overly helpful!) and considering the sample was 3 days old already, it didn’t seem that urgent, so the Microbiologist put it to the bottom of the list and got on busily calling out all of the Gram-negative bacilli and Gram-positive cocci, as these were more likely to be significant.
While sat in the cystic fibrosis multidisciplinary team (MDT) meeting a tricky clinical question was asked…
“We have a patient with an infective exacerbation of their cystic fibrosis with Burkholderia multivorans but she is allergic to Ceftazidime and Meropenem and gets bad gastrointestinal symptoms with tetracyclines. What do you think?” asked the Respiratory Consultant.
I really like these types of MDTs when I have to scratch my head and try to work out a solution but this one was a bit of a puzzler. I know Ceftazidime and Meropenem are often used to treat infections with Burkholderia spp. and that Minocycline is also an option, but what to do when these can’t be used? I had to admit I didn’t know for sure and that I would have to go and look at the literature and get back to them. So off I went to consultant the “Interweb”.
“Happy birthday to us, happy birthday to us, happy birthday dear Bug Blog, happy birthday to ussss…”
The Bug Blog is 5 years old! You may not realise it but we have been doing this together for 5 years. In that time we have written over 190 blogs on various microbiology related subjects as diverse as Proteus mirabilis (which Penny thinks smells like chocolate!), necrotising fasciitis and even Poldark’s Putrid Throat. It can be quite a challenge to find the time to write a blog every week but we strive to keep it up (on average we have managed about 40 per year). What makes it worthwhile is all of you out there taking the trouble to read what we have to say. So thank you for staying with us and reading all of our microbiological rambles…
A recent conversation got me thinking… a rare occurrence some would say… about the identification of bacteria. The patient I was discussing had two bacteria growing in his blood cultures and we weren’t sure if both were genuine or whether one was a skin contaminant. There was both a Staphylococcus spp. and a Proteus mirabilis growing, but the P. mirabilis was growing all over the Staphylococcus spp. preventing its further identification. I suggested putting up a CLED agar plate (see later in the blog) and a number of people looked at me like I was crazy… and whilst I do occasionally come up with some crazy ideas this really wasn’t one of the them. To understand my logic you have to know a bit about P. mirabilis, especially its laboratory identification. Let me explain further…
Last week saw an event of great celebration and much excitement and even made it onto the national TV news… No, I’m not talking about the marriage of Prince Harry and Megan Merkel... I’m talking about the birth of a little baby boy who turned up unexpectedly 3 months post-term!
Okay, so clearly 3 months post-term is not going to be a human baby. This baby weighed somewhere between 90-120 kg and took over 22 months to “cook” in his 35-year-old mum Thi-Hi-Way. Yep, he’s an elephant calf, and his keepers at Chester Zoo were caught completely by surprise when they came in to work on Friday morning to find a new-born elephant calf amongst their herd of Asian elephants. Wow what a job! They had thought his mum had miscarried as she had gone long past her due date, but low-and-behold they were wrong… I hope they call him Harry for obvious reasons!
In 1941 John Rex Whinfield and James Tennant Dickson of Calico Printers' Association of Manchester, England, patented a new compound that changed the way foods are packaged, the clothes we wear and many other manufacturing processes. The compound was poly(ethylene terephthalate) (PET), and is the most widely used polyester plastic worldwide. About 60% of the world’s PET is used to produce polyester often in the context of clothing production, with about 30% being used to produce plastic drinks bottles.
The Microbiology Consultant was waiting for the new Microbiology Registrar to finish the authorisation before going through any problems or questions they had. They started with their first question, a urine isolate which was identified as Pseudomonas aeruginosa but the antibiotic sensitivities didn’t make sense. The bacterium was sensitive to Co-amoxiclav and Ceftriaxone but resistant to Gentamicin and Amikacin. Pseudomonas aeruginosa is normally resistant to Co-amoxiclav and Ceftriaxone and sensitive to Gentamicin and Amikacin. A “nonsensical” or “incorrect” result like this should normally prompt further investigation as to what might be wrong before it is authorised or released.
The patient’s mother was at her wits end. Her little boy’s head was covered in scaly skin. At first she thought his scaly hair was dandruff so she had washed his hair in medicated shampoo but this was met with screams and tears. She thought he was being a bit extreme “it’s only dandruff” but guessed kids can be funny about having soap in their eyes. He just kept saying “mummy my head is really sore”. Tonight he had refused to have his hair washed and while trying to get him into bed, she noticed he was going bald! She was so alarmed that she brought him in to the Emergency Department for help.