MicrobeWorld

Viruses are not usually regarded as living cells. A virus 'particle' requires a living host cell in order to reproduce. Although we usually think of viruses as causing diseases, they also are an integral part of natural ecosystems controlling the size of bacterial populations by preying on them.... Read More

Gram-negative rods, possibly E. coli. (approx. 1000 X). Taken from the Wistreich Collection, appearing exclusively on MicrobeWorld. Read More

Flagella stain of Salmonella typhi. (approx. 1000 X). Taken from the Wistreich Collection, appearing exclusively on MicrobeWorld. Read More

“Predator” bacteria (green) surround “prey” bacteria (red) in this petri dish version of the Serengeti. Rather than eating their prey, however, predator cells release a chemical that activates a suicide gene in the prey. Prey cells also release a chemical, but one that promotes survival of the p... Read More

Gram-negative rods and coccobacilli. (Proteus vulgaris) (approx X1000). Taken from the Wistreich Collection, appearing exclusively on MicrobeWorld. Read More

In 1960, Australian immunologist Frank Burnet won a Nobel Prize for his contributions to immunology. Etsuko Uno and colleagues at the Walter and Eliza Hall Institute of Medical Research in Melbourne, Australia, explain Burnet's clonal selection theory in an animation of the body's response to St... Read More

Gram-negative rods. (approx. 1000 X). Taken from the Wistreich Collection, appearing exclusively on MicrobeWorld. Read More

Dark-field preparation of Treponema pallidum. (approx X1000). Taken from the Wistreich Collection, appearing exclusively on MicrobeWorld. Read More

Crystal violet stained cocci. Tetrads, and diplococcal and staphylococcal arrangements are present. (approx. 1000 X). Taken from the Wistreich Collection, appearing exclusively on MicrobeWorld. Read More

This scanning electron micrograph (SEM) depicts a grouping of Vibrio vulnificus bacteria; Mag. 13184x.
Vibrio vulnificus is a bacterium in the same family as those that cause cholera. It normally lives in warm seawater and is part of a group of vibrios that are called "halophilic" because they ... Read More

Safranin stained rods. (approx. 1000 X). taken from the Wistreich Collection, appearing exclusively on MicrobeWorld. Read More

Microscopic view of large numbers of bacilli showing streptobacillus arrangement. (approx. 1000 X). Taken from the Wistreich Collection, appearing exclusively on MicrobeWorld. Read More

This digitally-colorized scanning electron micrograph (SEM) of an untreated water specimen extracted from a wild stream mainly used to control flooding during inclement weather, revealed the presence of unidentified organisms, which included bacteria, protozoa, and algae. In this particular view... Read More

Gram stain of mixed culture of cocci and rods.Streptobacillus morphological arrangement is shown. (Approx X1000). Taken from the Wistreich Collection, appearing exclusively on MicrobeWorld. Read More

Gram-negative rods –Alcaligenes faecalis species (approx X1000). Taken from the Wistreich Collection, appearing exclusively on MicrobeWorld. Read More

Gram-negative rods – Morganella morganii species (approx X1000). Taken from the Wistreich Collection, appearing exclusively on MicrobeWorld. Read More

Gram-negative rods –Pseudomonas aeruginosa species (approx X1000). Taken from the Wistreich Collection, appearing exclusively on MicrobeWorld. Read More

(From left to right) NASA astrobiologist Danny Glavin, science writer Marc Kaufman, and geomicrobiologist and Princeton University professor Tullis Onstott, take questions from the audience at last night's Smithsonian-sponsored evening lecture entitled "Worms from Hell" that focused on the lates... Read More

Non-acid-fast rods (Corynebacterium species). (approx. X 1000). Taken from the Wistreich Collection, appearing exclusively on Microbeworld. Read More

This is a photomicrograph of Fusobacterium russii cultured in a thioglycollate medium for 48 hours.

Like the genus Bacteroides, Fusobacterium are anaerobic, gram-negative bacteria that are normal inhabitors of the intestine. Fusobacterium spp. are associated with pleuropulmonary and oral infe... Read More