Unlike human viruses that cause disease, yeast viruses do not cause any obvious illness in yeast. On the contrary, some viruses of yeast are beneficial and produce toxins that kill off competing yeast, allowing their host to thrive. We often think of viruses as agents of death and disease, but... Read More
Acid Fast stain done on a mix of Staphylococcus aureus and Mycobacterium smegmatis. The stain was done on a culture of M. smegmatis that was incubated on a TSA slant with 1ml TSB added at 37 degree's C for 4 days, S. aureus was incubated in TSB at 37 degree's C for 24 hrs. Several loops of eac... Read More
It's true that I adore microbiology, and I am lucky to teach it each year to my micronauts. So it was time to commit. Here is my second "Microbial Supremacy" tattoo! The artwork is by Peggy Muddles (http://www.redbubble.com/people/thevexedmuddler/works/15659350-microbial-badass-tattoo-full-co... Read More
Most of the strains used belong to the Bacillus genus and the rest are just random colorful petri dish contaminants. :-)
Author: Rositsa Tashkova, Université de Nantes, France Read More
In this blog, I share some "first word that comes to mind" responses of my freshman biology class to the words "germ," "bacteria," "cell," and "DNA." The way that we perceive an idea or concept definitely impacts our relationship with it. Thus, finding out what students think, coming into our ... Read More
Organisms grown in Fluid Thioglycollate Media w/out resazurin dye is a reducing media that uses sodium thioglycollate to chemically combine with dissolved oxygen to deplete the oxygen in the media. All organism except for Neisseria sicca were grown for 48 hours at 37 degrees C. Neisseria sicca i... Read More
In a healthy adult human body, most internal organs such as the brain, spleen, liver, and heart are devoid of microorganisms because the immune system keeps them in check. After human host death, however, the immune system falters and microorganisms proliferate throughout the body beginning in ... Read More
This episode: Bacteria are important for a good immune response to unadjuvanted influenza vaccines!
(14.6 MB, 16 minutes)
Methyl Red/Vogoes-Proskauer (MR-VP)
One medium used for two separate but related tests, identifying butanediol (VP) or acidic fermentation products (MR) as part of the IMViC test used in the identification of Enterobacteriaceae.
•Methyl Red (MR): detects the ability of an organism to produc... Read More
Serratia marcescens can form brilliant red colonies on LB agar due to the synthesis of the secondary metabolite prodigiosin. In the Microbiology teaching lab, we had students create pigment mutants of S. marcescens and these lovely shades of pink and white were collected for analysis. 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
MacConkey agar plate with invasive lactose fermenting E.coli which was isolated for fatal case of neonatal septicemia.
Photo was taken after 12h incubation under 37C.
Credits: Povilas Kavaliauskas, Vilnius University, Lithuania. Read More
Nitrate reduction test for the reduction of nitrate in nitrate media, to determine if the bacteria contains nitrate and/or nitrite reductase. Organism were incubated for 48 hr's at 37 degree's in nitrate media then reagents added.
Nitrate broths after the addition of 10 drops re... Read More
"Two types of bacteria found in the soil have enabled scientists to get the dirt on how resistance to antibiotics develops along with a separate survival strategy.The study identifies an atypical antibiotic molecule and the way in which the resistance to that molecule arises, including the ident... Read More
What do you get when you kiss a Petri dish? Bacteria and yeast colonies that grow into a pretty collage composed of different colors and morphologies. This is an LB agar plate incubated at room temperature for several days. Read More
Streak plate isolation showing colonial morphology of Bacillus subtilis on trypticase soy agar (TSA) incubated for 24 hours at 37oC. Note the rough and dry/matte texture characteristic of this organism’s growth. Read More
Streptomycetes are a member actinomycete family. Streptomycetes are usually found in soil and are important decomposers. They are aerobic, gram-positive, filamentous rods that create branching hyphae. They also produce more than half of the world's antibiotics, and are therefore very valuable in... Read More
This is a picture of the Christmas tree in the University of Colorado Hospital Microbiology Department.
The tree is adorned with homemade culture plate ornaments (one for each staff member) and topped with a stuffed Staphylococcus aureus microbe. Read More
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