Yes really this is made with bacteria on agar…amazing isn’t it?! This was the 2018 winner of the American Society for Microbiology agar art contest, "The battle of winter and spring," by Ana Tsitsishvili. It is staggeringly good! Every time I see this it takes my breath away. 

Now some people see agar art as a waste of resources, time and money… but I think they are wrong. In order to produce something this incredible you have to know so much about bacteria and fungi, how they appear in different environments, how different agar affects them and how they interact with each other.

Personally I think every microbiology lab should run an agar art contest every year… maybe I should start this locally… anyway back to the art…
 
To produce a picture on agar out of bacteria and fungi you need to exploit a number of criteria such as organism colour, texture, colonial size and type of haemolysis as well as using inhibition to create various effects. Okay, it helps to be artistic as well (and I’ll show you my attempt at the end… prepare to laugh, it’s not in the ASM league!).
 
Colour
Colour can be used in two main ways either the bacterial pigments or changes that occur in the agar itself.

​Some bacteria and fungi commonly isolated in clinical microbiology laboratories produce specific colours:

• Staphylococcus aureus – golden colour (hence the name aureus, the Latin for golden)
• Serratia marcescens – red (one of the theories as to why statues of the Virgin Mary can “cry blood”; it’s thought to be this Gram-negative bacterium growing on the statues!)
• Pseudomonas aeruginosa – various colours possible including green, blue, reddish brown (P. aeruginosa produces chemicals called pyoverdin - green, pyocyanin - blue and pyorubin – reddish brown)
• Coagulase negative Staphylococcus spp. – normally “boring” white (common contaminant) but great for making snowflake artwork
• Micrococcus luteus – lemon yellow (common contaminant)
• Rhodococcus equi – salmon pink (can cause severe infections in HIV positive patients and in horses causes foal fever)
• Rhodotorula spp. – red (this is the red waxy mould you sometimes see growing in showers)
• Chromobacter violaceum – purple (C. violaceum produces a pigmented antibiotic called Violacein which is a deep purple colour)
• Aspergillus niger – black (the spores of this fungus are black; it is an opportunistic pathogen)

 
These artists’ creations below use just one bacterium, S. marcescens (red) but I'm not sure what Mike Wazowski (Monster Inc.) is made of but I hope you agree the effect is quite striking!

​Another way to exploit colour in the laboratory is to use an indicator agar; these types of agar produce a particular colour that allow you to spot specific bacterial species:

• Blood agar – alpha and beta haemolysis of blood can give interesting art potential (alert! alert! the word interesting in a microbiology blog!!!); alpha haemolysis (e.g. Viridans Streptococcus spp.) gives a green colour whereas beta haemolysis (e.g. Streptococcus pyogenes) causes clear zones of complete haemolysis around the colonies
• Cysteine Lactose Electrolyte Deficient (CLED) agar is normally turquoise but goes yellow when bacteria ferment the sugar lactose to produce an acid, e.g. Escherichia coli, Klebsiella spp.
• MacConkey agar is normally an orange/red but goes bright pink when bacteria ferment the lactose in the agar, e.g. Escherichia coli, Klebsiella spp.
• Xylose Lysine Deoxycholate (XLD) agar is normally a rich red but some bacteria produce indole creating black colonies, e.g. Salmonella spp. and Proteus mirabilis

​In this example the CLED agar has been used to give a background turquoise colour for the water in which this microbial Koi carp is swimming... Unsurprisingly this is 2019 winner of the American Society for Microbiology agar art contest, brilliant hey!?
 
Using chromogenic agar is a way of taking colour to the next level!
This type of agar contains colourless compounds called chromogens which can be split by specific enzymes or chemicals to produce a pigment. The choice of chromogen can be used to detect an enzyme or chemical specific to a bacterial species and therefore the bacterial species itself. These types of indicator agar are used as screening agars for certain bacteria (e.g. MRSA agar) or to detect, quickly and cheaply, a limited array of bacterial species in a specific sample (e.g. UTI agar). Chromogenic UTI agar is especially good for agar art as different bacteria give different colours all on the same agar plate, it’s a bit like those wash-over colouring books you got as kids!

​On this agar (Chromagar Orientation) specific bacteria give particular colours:

• E. coli = dark pink to reddish
• Enterococcus spp. = turquoise blue
• Klebsiella spp., Enterobacter spp., Citrobacter spp. = metallic blue
• Proteus mirabilis = brown halo
• Pseudomonas aeruginosa = cream, translucent
• S. aureus = golden, opaque, small
• Staphylococcus saprophyticus = pink, opaque, small

 
If you get it right with chromogenic agar, the variation of colours can be stunning:

​BUT if you really want to get creative, start to use Texture!
It’s not just the colour of microorganisms you can creatively exploit, but their texture as well. Some bacteria are smooth, some are crinkled, some have a glassy appearance, others are mucoid and slimy and some eat into the agar itself creating a concave appearance to the art.

• Smooth – Staphylococcus spp.
• Crinkled – Actinomyces israelli
• Glassy – Bacillus spp.
• Mucoid – Pseudomonas aeruginosa
• Slimy – Klebsiella pneumoniae
• Eats agar – Eikenella corrodens

You can even use a Staphylococcus spp. and add hydrogen peroxide to activate the enzyme catalase, producing water, oxygen and foamy beer!

​Fungi are even more textured, especially the moulds such as Aspergillus spp., zygomycetes and dermatophytes. These are raised and fluffy and can be very dramatic. Just look at the volcano agar art below; a specific fungal agar has been heaped up and then cultured with the mould Cledosporium spp. to give the mound a rocky appearance… pure genius, it came 3rd this year in the American Society for Microbiology agar art contest.

​Hold yourselves back, let’s consider - inhibition
The final type of criteria that could be used to create agar art is the ability of microorganisms to inhibit each other. Most antimicrobials actually come from microorganisms and the truly great agar artists use these naturally occurring antimicrobial compounds to create clear zones between coloured colonies or to get colonial edges to heap up and change shape. Some of this is extraordinary; in the example below the yeast Saccharomyces cerevisiae is used in two forms, one producing an antifungal which inhibits another S. cerevisiae creating a clear zone with heaped up blue edges… wow!

​So there you have it; lots of different ways to produce agar art using different bacteria and fungi. But it’s not as easy as it seems. The entrants to the ASM agar art competition are truly fantastic, I think you’ll agree. Most of us can only aspire to produce such amazing results BUT the knowledge behind creating agar art is the fundamental knowledge of microbiology. It’s about an intimate knowledge of the microorganisms we deal with every day.
 
Okay, it might seem frivolous and a waste of energy and resources but is it? Is all the knowledge gained a waste? I don’t think so… take a look at my agar art! Ermmmmmm… at least it’s recognisable!!! … “Is it a multi-eyed alien?” No it’s a Christmas tree!!! OK it’s certainly not going to win any competitions!?

​In the meantime take a look at the ASM site for previous entrants some are truly amazing, and watch the video about how to make agar art.

Here’s a festive selection of agar creations from the Internet to inspire you… so you think you could do better?! Post your images up on our Facebook page for us all to see and comment on… (please respect decency standards! It’s not clever to make a phallic object using salmon pink Rhodococcus equi and Pseudomonas aeruginosa brown blobs!!!)

The Microbiologist picked up the phone to call out a result.
 
“This one looks interesting” he said to himself even though he knew he had been told never to use the word interesting in relation to microbiology…. Ever…!
 
“You have a baby boy on the ward with salmonellosis, what’s the story?” he asked when the Paediatric SHO answered the phone.
 
“He’s a six week old who developed bloody diarrhoea a couple of days ago and started vomiting. He was febrile and looked septic so we started him on empirical IV Ceftriaxone.”
 
“Any pets?” asked the Microbiologist.
 
“He’s only 6 weeks old, why would he have any pets?” answered the tired junior.
 
“Not him, the family; specifically reptiles. Any snakes or lizards?”
 
“I have no idea.”
 
“Well carry on with the IV Ceftriaxone as he has a Salmonella species in his blood culture and call me back about the reptiles… no wait, I’ll come up and ask myself.”
 
The junior doctor hung up. Muttering to himself about mad Microbiologists he wandered off to get on with some other work.
 
So why did the Microbiologist want to know about reptiles? Was he just mad or was there method to his madness?

The Biomedical Scientist walked hesitantly into the duty Microbiologists office.
 
“We have a mould growing in a blood culture” they said.
 
“You mean a yeast?” asked the Microbiologist.
 
“Nope, definitely a mould” replied the BMS.
 
“A contaminant maybe?” asked the Microbiologist again, now starting to hope this was the case.
 
“Nope, definitely not a contaminant” replied the BMS.
 
“Please tell me this was handled in Cat 3?” asked the Microbiologist again, starting to sound worried and thinking he should maybe put the Health and Safety Executive (HSE) telephone number into his phone!
 
“Nope, not in Cat 3” replied the BMS looking crest fallen, “but it should have been… I think it’s Talaromyces marneffei”
 
The Microbiologist just stared at them lost for words… why did it always happen when he was on duty?!
 
What is Talaromyces marneffei?
T. marneffei is a dimorphic fungus; it has two types of growth depending on the temperature (a bit like cheese! Cheese is a solid block when in the fridge but when sliced and put on toast under a grill it’s all gooey!!!) It used to be called Penicillium marneffei, but like many other microorganisms it has undergone a recent name change just to keep us on our toes.

Once upon a time… a long time ago… in a distant land… and a galaxy far, far away

​The Microbiologist was busy authorising the laboratory results when his phone rang. The call identification showed it was Accident and Emergency (A&E) majors so it might be urgent…It was the A&E doctor.
 
“I have a patient with positive blood cultures who we sent home 4 days ago”, they said in a slightly panicked voice.
 
“What did the blood culture grow?” asked the Microbiologist.
 
“They had a temperature of 38.5 oC and so had blood cultures taken, but clinically it looked like they had a viral upper respiratory tract infection, so we discharged them”, came the reply.
 
“But what did the blood culture grow?” asked the Microbiologist again slightly louder this time.
 
“The patient was fine, the temperature settled with Paracetamol. But I think I need to get them back in, repeat the blood cultures and start IV Piptazobactam for sepsis” continued the doctor starting to border on the hysterical.
 
“STOP TALKING, JUST TELL ME WHAT THE BLOOD CULTURE GREW!” shouted the Microbiologist in a last ditch effort to break through the A&E doctors ranting.
 
“Oh! It grew a Cutibacterium spp. and I’ve never heard of it before so thought it must be significant”.
 
“Okay. Take a deep breath and calm down” said the Microbiologist “you might not have heard of Cutibacterium but I am sure you have heard of Propionibacterium acnes?”
 
“Yea, that’s a skin contaminant but it definitely says Cutibacterium” muttered the A&E doctor now frustrated at the Microbiologist!
 
“Good, now let me explain the joy that is changes in names…” replied the Microbiologist, "while you're on the phone do you know what these used to be called too?!? I'm doing a quiz for Friday lunchtime..."

​I’ve had the dubious pleasure of dealing with various incidents and outbreaks over the years. They can be very stressful experiences for everyone concerned, but a clear methodical approach can go a long way to alleviating the levels of stress both in both you and your colleagues.
 
Imagine the scenario:
It’s 9am and the Senior Biomedical Scientist knocks on your door “ummm the laboratory has inadvertently processed a tissue sample containing Brucella melitensis on the open bench!”

It was another dull and dreary afternoon giving advice when an excited Dermatologist phoned about a patient with funny skin lumps. (Microbiologists get excited about bugs, Dermatologists get excited about rashes, so lumps and bumps together… what can I say…we were very excited!!)
​
Their patient was a keen gardener who had been clearing a large number of blackthorn trees (good for making sloe gin) and despite wearing thick gloves had managed to get pricked and scratched all the way up their arms. At the site of one of those puncture wounds they had developed a small red lump which had eventually turned into a small ulcer. The ulcer hadn’t got much better and over the next few weeks the patient had noticed a number of other lumps appearing up their arm and then hard swellings in their armpit.

​Yep, it’s coming up to that time of year. All of Microbiology is excited as there is about to be a holiday and eggs are likely to feature in a big way… no not Easter!!! Its holiday time and people will be going to exotic countries and bringing back souvenir parasites and their eggs will be involved in working out what is wrong with them. Yep us Microbiologists’ love eggs, not just the chocolate variety. I don’t know, you lot all have chocolate on the brain :-)

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.