Koch’s postulates, criteria designed to establish a causal relationship between a causative microbe and a disease.
(Source: Wiki, licensed under the Creative Commons Attribution-Share Alike 3.0 Unported License)
Dark blue - staining distemper virus inclusion body within the cytoplasm of a neutrophil (at the 2 o ’ clock position) of an unvaccinated dog with acute distemper; slide was stained with a commercial Diff - Quik stain (recommended) to elucidate inclusion bodies.
Examination of peripheral blood smears or exfoliative cytology (e.g., conjunctival scrapings) for intracellular distemper inclusion bodies is highly diagnostic, particularly in the early stages of infection.
(Source: Blackwell’s Five-Minute Veterinary Consult- Clinical Companion)
Microvilli are microscopic cellular membrane protrusions that increase the surface area of cells, and are involved in a wide variety of functions, including absorption, secretion, cellular adhesion, and mechanotransduction. These finger-like projections from the small intestine are also home to huge numbers of microbes.
Image courtesy of Azusa Hotta et al., Journal of Cell Biology
(Source: Flickr / thejcb)
*1st Place: Sensing Danger*
Olena Kamenyeva, National Institute of Health, Bethesda, Maryland.
Subject: Recruitment of neutrophils to the site of laser damage in mouse inguinal lymph node.
*2nd Place: Sperm From Two Males Competing*
Stefan Lüpold, Syracuse University, Syracuse, New York.
Subject: Sperm from two males competing within reproductive tract of a female fruit fly (Drosophila melanogaster). Magnification: 400x.
*3rd Place: Growing Complexity in the Kidney*
Nils Lindstrom, University of Edinburgh, United Kingdom.
Subject: Complexity of ureteric bud branching and nephron formation.
*Honorable Mention: The Rotifer Limnias melicerta*
Fengzhu Xiong, Micropolitan Museum Rotterdam, The Netherlands.
Subject: Limnias melicerta (a rotifer). Magnification: 400x.
Streptomyces species bacterium in an agar plate
Streptomyces species are found worldwide in soil and are important in soil ecology. Much of the characteristic earthy smell of soils arises from chemicals called geosmens given off by Streptomyces species. Streptomycetes are metabolically diverse and can “eat” almost anything, including sugars, alcohols, amino acids, organic acids, and aromatic compounds. They have unique abilities in their production of numerous antibiotics. There is considerable interest in these organisms as agents for bioremediation.
Bacteriophages escape from a dying streptococcus bacterium, ready to find another victim. Their ability to infect and kill specific strains may lead to new treatments for antibiotic-resistant bacteria.
Photograph by Dennis Kunkel Microscopy, Inc
Variola virus (smallpox)
Smallpox is considered to be a disease of antiquity, but was once the scourge of all mankind. It is a member of the poxviridae family, has a double stranded DNA and is ellipsoid-shaped with an outer envelope. The virus only infects humans and has one stable serotype.