Mannitol Salt Agar (MSA)
•Important Ingredients: Phenol red, mannitol (sugar), 7.5% NaCl
•Differential: between pathogenic S. aureus and S. epidermidis
•Selective: NaCl inhibits non-halophilic organisms. Organism that can grow are halophilic.
•Mannitol Fermentors: fermentation of acid cau... Read More
Scanning electron micrograph of Yersinia pestis, which causes bubonic plague, on proventricular spines of a Xenopsylla cheopis flea. Credit: National Institutes of Health/Department of Health and Human Services (NIAID) Read More
This swirling mass may look like some kind of LSD trip, but it's actually fractal artwork created using bacteria.
Produced by Eshel Ben-Jacob—a scientist-cum-artist at Tel Aviv University—the piece came about thanks to two strains of bacteria which grew together in interesting and weird ways.... Read More
The following picture shows the isolated black colonies of Salmonella on Salmonella-Shigella (S-S) Agar. S-S Agar is used as a selective and differential medium for the isolation of Salmonella and some Shigella species. The inclusion of bile salts is to inhibit gram-positive organisms. Ferric ci... Read More
Got your attention, eh? This page discusses why so many people believe that antibiotics kill viruses, and what you can do about that myth. Actually, it's not even a myth ... antibiotics DO work against viruses. The problem is that the word "antibiotics" is redefined by some to be a synonym of... Read More
Bacitracin test done on a lawn of Streptococcus pyogenes grown on blood agar. The zone of inhibition around the bacitracin disc, approx 14mm measuring the entire length of the zone, indicates sensitivity. The zone of inhibition is red because the red blood cells did not lyse. Grown for 24 hr... Read More
For those of us who are normal, non-scientist people, an image of a virus doesn't necessarily hold any meaning. Which floating orb is a healthy cell? And which one is the actual virus? The CGSociety recently invited artists to create renderings of the HIV virus in blood—and the winning images ar... Read More
Washington University in St Louis chemist Timothy Wencewicz says we’ll stay ahead of antibiotic resistance only if we find drugs with new scaffolds, or core chemical structures. One promising candidate, an antibiotic made by a bacterium than infects plants, caught his attention because it contai... Read More
There are many reasons why bacteria evolve resistance to antibacterials, but one of the preventable reasons is the over-prescription of antibacterials to patients who don't have bacterial infections. But how to get people to stop asking for antibacterials? My suggestion is to stop using the wor... Read More
In this short post, I celebrate Valentine's Day with words of light---using bioluminescent bacteria! Read More
Isolated colony of Mycobacterium smegmatis grown on TSA for 96 hrs at 37 degrees C. Margin is lobate with an irregular-rhizoid form. Image taken using transmitted light. Read More
Growth of Streptococcus mitis on blood agar demonstrating alpha hemolysis seen as a greenish color around the growing colonies due to a reduction of the hemoglobin to methemoglobin in the surrounding agar. Image taken using transmitted light. Read More
Three organisms inoculated in TSB to look at tube morphology. From left to right:
Staphylococcus aureus: flocculent growth/turbid, growth throughout the tube.
Mycobacterium smegmatis: pellicle, growth at the top of the tube. M. smegmatis tends to stick to the tube and grow up the side.
Ba... Read More
It's Friday and I can finally enjoy the beach! So I thought it would be nice to reflect my excitement at work growing this happy Listeria monocytogenes ;) Read More
In this blog entry, I explore how students can use their creativity to learn microbiology in innovative and often artistic ways. It makes learning more personal! Read More
A relatively straightforward classroom experiment produces fascinating images by students at the University of Surrey when they imprinted their smartphone onto a bacterial growth medium. Read More
Olympus Bioscapes, Honorable Mention, Dr. Petr Znachor, Laboratory of Phytoplankton Ecology, Institute of Hydrobiology,Ceske Budejovice, Czech Republic.
Specimen: Cyanobacterium Anabaena planctonica, Technique: Nomarski contrast, 20x Objective Read More
I was checking our fungal culture plates in the microbiology lab...and came across this happy little colony of Candida albicans on an Inhibitory Mold Agar plate. Kind of made my day! Read More
From the shiny, strong nacre that gives abalone shells an unbreakable, opaline sheen, to the goopy mix of proteins fired by a velvet worm that solidify and trap prey upon impact, nature is packed with inspiration for scientists designing new materials.
Waterproof adhesives and self-cleaning s... Read More