A spirochaete or spirochete is a member of the phylum Spirochaetes, which contains distinctive diderm (double-membrane) gram-negative bacteria, most of which have long, helically coiled cells. Spirochaetes are chemoheterotrophic in nature, with lengths between 3 and 500 μm and diameters around 0.09 to at least 3 μm.
Listeria monocytogenes is the species of pathogenic bacteria that causes the infection listeriosis. It is a facultative anaerobic bacterium, capable of surviving in the presence or absence of oxygen. It can grow and reproduce inside the host's cells and is one of the most virulent foodborne pathogens: 20 to 30% of foodborne listeriosis infections in high-risk individuals may be fatal. Responsible for an estimated 1,600 illnesses and 260 deaths in the United States annually, listeriosis ranks third in total number of deaths among foodborne bacterial pathogens, with fatality rates exceeding even Salmonella spp. and Clostridium botulinum. In the European Union, listeriosis follows an upward trend that began in 2008, causing 2,161 confirmed cases and 210 reported deaths in 2014, 16% more than in 2013. Listeriosis mortality rates are also higher in the EU than for other foodborne pathogens.
Leptospirosis is a blood infection caused by the bacteria Leptospira. Signs and symptoms can range from none to mild to severe. Weil's disease, the acute, severe form of leptospirosis, causes the infected individual to become jaundiced, develop kidney failure, and bleed. Bleeding from the lungs associated with leptospirosis is known as severe pulmonary haemorrhage syndrome.
A tumour inducing (Ti) plasmid is a plasmid found in pathogenic species of Agrobacterium, including A. tumefaciens, A. rhizogenes, A. rubi and A. vitis.
Leptospira is a genus of spirochaete bacteria, including a small number of pathogenic and saprophytic species. Leptospira was first observed in 1907 in kidney tissue slices of a leptospirosis victim who was described as having died of "yellow fever".
Stenotrophomonas maltophilia is an aerobic, nonfermentative, Gram-negative bacterium. It is an uncommon bacterium and human infection is difficult to treat. Initially classified as Bacterium bookeri, then renamed Pseudomonas maltophilia, S. maltophilia was also grouped in the genus Xanthomonas before eventually becoming the type species of the genus Stenotrophomonas in 1993.
Leptospira noguchii is a gram-negative, pathogenic organism named for Japanese bacteriologist Dr. Hideyo Noguchi who named the genus Leptospira. L. noguchii is famous for causing the febrile illness in Fort Bragg, NC during World War II. There was 40 cases of this fever documented during each summer from 1942 to 1944; however, there were 0 deaths recorded from this outbreak. Unlike other strains of Leptospira that cause leptospirosis, L. noguchii is characterized by showing a pretibial rash on the victim. Its specific epithet recognises Hideyo Noguchi.
The prokaryotic cytoskeleton is the collective name for all structural filaments in prokaryotes. It was once thought that prokaryotic cells did not possess cytoskeletons, but advances in visualization technology and structure determination led to the discovery of filaments in these cells in the early 1990s. Not only have analogues for all major cytoskeletal proteins in eukaryotes been found in prokaryotes, cytoskeletal proteins with no known eukaryotic homologues have also been discovered. Cytoskeletal elements play essential roles in cell division, protection, shape determination, and polarity determination in various prokaryotes.
Pathogenic bacteria are bacteria that can cause disease. This article focuses on the bacteria that are pathogenic to humans. Most species of bacteria are harmless and are often beneficial but others can cause infectious diseases. The number of these pathogenic species in humans is estimated to be fewer than a hundred. By contrast, several thousand species are part of the gut flora present in the digestive tract.
Leptospira interrogans is a Gram negative, obligate aerobe spirochete, with periplasmic flagella. When viewed through a dark-field microscope, it often resembles a question mark, and this gives the species its name. It is a member of the genus Leptospira. Some important pathogenic serovars from this species are Canicola, Icterohaemorrhagiae and Australis. L. interrogans is difficult to culture, requiring special media and extended incubation periods.
The AB toxins are two-component protein complexes secreted by a number of pathogenic bacteria. They can be classified as Type III toxins because they interfere with internal cell function. They are named AB toxins due to their components: the "A" component is usually the "active" portion, and the "B" component is usually the "binding" portion. The "A" subunit possesses enzyme activity, and is transferred to the host cell following a conformational change in the membrane-bound transport "B" subunit. These proteins consist of two independent polypeptides, which correspond to the A/B subunit moieties. The enzyme component (A) enters the cell through endosomes produced by the oligomeric binding/translocation protein (B), and prevents actin polymerisation through ADP-ribosylation of monomeric G-actin.
Niyaz Ahmed is a professor of microbial sciences, genomicist, and a veterinarian by training, based in Hyderabad.
Leptospira fainei is a pathogenic species of Leptospira, first isolated from pigs in Australia and named for University of Otago and Monash University microbiologist Dr. Solomon Faine.
Leptospira broomii is a species of Leptospira isolated from humans with leptospirosis. The type strain is 5399T.
Spiral bacteria, bacteria of spiral (helical) shape, form the third major morphological category of prokaryotes along with the rod-shaped bacilli and round cocci. Spiral bacteria can be subclassified by the number of twists per cell, cell thickness, cell flexibility, and motility. The two types of spiral cells are spirillum and spirochete, with spirillum being rigid with external flagella, and spirochetes being flexible with internal flagella.
Naegleria fowleri, colloquially known as a "brain-eating amoeba", is a species of the genus Naegleria, belonging to the phylum Percolozoa, which is technically not classified as true amoeba, but a shapeshifting amoeboflagellate excavate. It is a free-living, bacteria-eating microorganism that can be pathogenic, causing an extremely rare sudden, severe and usually fatal brain infection called naegleriasis or primary amoebic meningoencephalitis (PAM). This microorganism is typically found in bodies of warm freshwater, such as ponds, lakes, rivers, hot springs, warm water discharge from industrial or power plants, geothermal well water, poorly maintained or minimally chlorinated swimming pools, water heaters, soil, and pipes connected to tap water. It can be seen in either an amoeboid or temporary flagellate stage.
Bacterial secretion systems are protein complexes present on the cell membranes of bacteria for secretion of substances. Specifically, they are the cellular devices used by pathogenic bacteria to secrete their virulence factors to invade the host cells. They can be classified into different types based on their specific structure, composition and activity. Generally, proteins can be secreted through two different processes. One process is a one-step mechanism in which proteins from the cytoplasm of bacteria are transported and delivered directly through the cell membrane into the host cell. Another involves a two-step activity in which the proteins are first transported out of the inner cell membrane, then deposited in the periplasm, and finally through the outer cell membrane into the host cell.
Leptospira alstonii is a gram negative, mobile, spirochete. It is flexible, helical, and motile by means of two periplasmic flagella. It is obligately aerobic and oxidase positive. It was named after J. M. Alston, a British microbiologist who made significant contributions to the study of Leptospirosis. It is one of nine human or animal pathogenic species of Leptospira. It was originally isolated from material submitted to the Veterinary Diagnostic Laboratory at Iowa State University during an outbreak of swine abortion in 1983. It has been isolated and stored in liquid nitrogen or Ellinghausen-McCullough-Johnson-Harris medium. It also has been isolated in China from a frog. The strain is also available from culture collections of the WHO collaborating centers. Lipase is not produced by this species. NaCl is not required for growth. Growth is inhibited by 8-azaguanine at 225 µg/mL or 2,6-diaminopurine (10 µg/mL) and copper sulfate. It contains serovars from the serogroup ranarum. DNA G+C content is 39±8 mol%.
Leopold Kirschner was an Austro-Hungarian, Dutch, and New Zealand bacteriologist specializing in leptospirosis. He is known for his work on the survival of Leptospira spp in the environment, research on conditions and media for Leptospira growth, his role in the initial discoveries of leptospirosis in New Zealand, for early epidemiologic descriptions of leptospirosis as an occupational disease of dairy farmers, and for the major pathogenic Leptospira species, Leptospira kirschneri, that was named in his honor.
Joseph Michael Vinetz is a Professor of Medicine and Anthropology at Yale University, Research Professor at the Universidad Peruana Cayetano Heredia and Associate Investigator of the Alexander von Humboldt Institute of Tropical Medicine at the Universidad Peruana Cayetano Heredia.
