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
A colorized electron microscope image captures delicate chains of streptococcus in a laboratory sample. Though some strep infections can be deadly, many strains are harmless—among the thousands of benign beings that make their home in our bodies.
Photograph by Martin Oeggerli, with support fr... Read More
A particular type of ancient rock art in Western Australia maintains its vivid colours because it is alive, researchers have found.
While some rock art fades in hundreds of years, the "Bradshaw art" remains colourful after at least 40,000 years.
Jack Pettigrew of the University of Queensla... 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
clostridium perfringens stormy fermentation in milk Read More
Germaphobes, maybe you're on to something.
Sickness-causing bacteria and viruses can lurk on surfaces long after they're expelled in an infected person's sneeze or snot. Some can even stay on a surface for months, given the right conditions. While the ability of these microorganisms to actual... Read More
This transmission electron micrograph (TEM) depicted a number of Nipah virus virions that had been isolated from a patient's cerebrospinal fluid (CSF) specimen.
Nipah virus is a member of the family Paramyxoviridae, and is related, but not identical to Hendra virus. Nipah virus was initially ... Read More
Bioluminescent art blends science and creativity to create images that can only be seen in the dark. What do you get when you add a chemical engineer, a graphic designer and a research scientist? Beautiful art. In a wondrous combination of nature and design, bioluminescent art involves using nat... Read More
Artist Sonja Bäumel explores the skin microbiome in her project Cartography of the Human Body. Bacteria isolated from Bäumel’s skin were characterized and grown individually, then used to reconstruct an artificial microbiome with many layers of differently-colored species. Giant petri dishes gre... 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
This past weekend the USA Science and Engineering Festival came to Washington, D.C. The American Society for Microbiology and MicrobeWorld were present with our own booth in which we offered several microbe-related activities for attendees of all ages.
In this picture, Barbara Hyde, director... 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
Serratia marcesens is a Gram-negative, rod-shaped bacterium that is commonly found in soil, water, on plants and in animals and thrives in damp conditions. This organism is well known for its production of the blood red pigment, prodigiosin. Production of prodigiosin can be influenced by several... Read More
Aspergillus sp. Early stage with sterigma and spores. Nomarski technique (800X) 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
Unknown organism isolated from a swab taken off the bottom of a shoe. Students were asked to swab something in the classroom. One swab was done on the bottom of a shoe and incubated on a TSA plate for 48 hrs at 37 degree’s C. The organism was difficult to scrape so a small chunk of the organis... Read More
A streak plate of Strep pyogenes on blood agar, stock culture used for class, was kept at room temp for 1 month. Before disposal a contaminant, presumably environmental, was seen on the plate. The pigment was opaque tan/yellow and with a mucoid surface. Lobate marigins with raised irregular-rh... Read More
Kirby-Bauer disk diffusion susceptibility test on coagulase-negative Staphylococcus aureus and E.coli grown on Mueller-Hinton agar with tetracycline (30 µg), cephalothin (30 µg), erythromycin (15 µg), chloramphenicol (30 µg), vancomycin (30 µg), penicillin (10 µg), streptomycin (10 µg), and novo... Read More