Salmonella enteritidis. Salmonella Enteritidis and Salmonella Typhimurium are the most common in the United States and account for half of all human infections. Strains that cause no symptoms in animals can make people sick, and vice versa. If present in food, it does not usually affect the taste, smell, or appearance of the food. The bacteria live in the intestinal tracts of infected animals and humans. Photo by Jean Guard-Petter. USDA
A colorized scanning electron micrograph of Mycobaterium tuberculosis, the bacteria that cause TB. Tuberculosis, commonly known as TB, is a contagious and an often severe airborne disease caused by a bacterial infection. TB typically affects the lungs, but it also may affect any other organ of the body. It is usually treated with a regimen of drugs taken for 6 months to 2 years, depending on the type of infection.
This 1975 transmission electron micrograph (TEM) revealed the presence of a number of infectious bronchitis virus (IBV) virions, which are Coronaviridae family members, and members of the genus Coronavirus. IBV is a highly contagious pathogen, which infects poultry of all ages, affecting a number of organ systems including the respiratory and urogenital organs. Credit: Dr. Fred Murphy; Sylvia Whitfield, CDC
Clostridium difficile. A colour-enhanced scanning electron micrograph image showing a cluster of Clostridium difficile on a surface. Clostridium difficile is a species of Gram-positive bacteria that causes severe diarrhea and other intestinal disease when competing bacteria in the gut flora have been wiped out by antibiotics. Annie Cavanagh. Wellcome Images. The Cell: an Image Library
Staphylococcus aureus: USA:300 is a strain of gram-positive coccus bacteria responsible for Methicillin-resistant Staphylococcus aureus (MRSA), or Staph infection in humans. This strain of S. aureus is resistant to β-lactam antibiotics. When cultured, this bacteria appears as golden clusters. The golden color is the result of a carotenoid pigment that protects the bacteria against host-immune system reactive oxygen species, and adds to the bacteria's virulence.
Nikon Small World Honorable Mention 2008 photomicrography competition, Dr. Petr Znachor, Institute of Hydrobiology, Ceske Budejovice, Czech Republic Coiled filamentous cyanobacterium Anabaena sp. (600x) Technique: Nomarski Differential Interference Contrast
This is a live image of the of Diatom Arachnoidiscus under 40x magnification. The picture shows the diatom's silicified cell wall, which forms a pillbox-like shell (frustule) composed of overlapping halves that contain intricate and delicate markings. The picture was obtained with new video enhanced polychromatic (VEP) polscope after background subtraction.
Large (about 5 mm in diameter), lactose positive colonies of Klebsiella pneumoniae on desoxycholate-citrate agar. Cultivation 37°C, 24 hours. Klebsiella pneumoniae is a common source of hospital-acquired infections. Some of the strains can carry plasmids that harbour genes conferring resistance to almost all antibiotics. These bacteria are called multiresistant or, informally, superbugs or super bacteria.