Borrelia burgdorferi is a spirochete and the cause of Lyme disease, a tick transmitted illness of humans and animals. B. burgdorferi may persist in humans and animals for months or years following initial infection, despite a robust humoral immune response. B. burgdorferi resembles other spirochetes in that it is a highly specialized, motile, two-membrane, spiral shaped bacteria which lives primarily as an extracellular pathogen. B. burgdorferi has an unusual genome compared with other eubacteria which includes a linear chromosome approximately one megabase in size and numerous linear and circular plasmids

Giardiasisis a diarrhoeal illness caused by a single celled microscopic protozoan parasite ,Giardia lamblia, also known as Giardia intestinalis. Giardia lamblia exists in two forms, an active form called a trophozoite, and an inactive form called a cyst. The active trophozoite attaches to the lining of the small intestine and is responsible for causing the signs and symptoms of giardiasis. The trophozoite cannot live long outside of the body and spread of infection is via the cyst which is excreted in the host's faeces. When it is ingested, stomach acid activates the cyst, and the cyst develops into the disease causing trophozoite in the new host. Giardiasis is diagnosed by finding cysts or trophozoites in the faeces

Campylobacteriosis is an infectious disease caused by bacteria of the genus Campylobacter. Most people who become ill with campylobacteriosis get diarrhea, cramping, abdominal pain, and fever within 2 to 5 days after exposure to the organism. The diarrhea may be bloody and can be accompanied by nausea and vomiting. The illness typically lasts 1 week. Some persons who are infected with Campylobacter don't have any symptoms at all. In persons with compromised immune systems, Campylobacter occasionally spreads to the bloodstream and causes a serious life threatening infection. The Campylobacter organism is actually a group of spiral shaped bacteria that can cause disease in humans and animals. Most human illness is caused by one species, called Campylobacter jejuni, but 1% of human Campylobacter cases are caused by other species

The spiral shaped bacterium Helicobacter pylori is strongly associated with inflammation of the stomach and is also implicated in the development of gastric malignancy. H. pylori is known to cause peptic ulcers and chronic gastritis in human. It is associated with duodenal ulcers and may be involved in development of adenocarcimona and low-grade lymphoma of mucosa associated lymphoid tissue in the stomach. More recently this bacterium has also been implicated with a number of vascular disorders including heart disease. It is not clear how H. pylori is transmitted or why some patients become symptomatic while others do not. The bacteria are most likely spread from person to person through fecal-to-oral or oral-to-oral routes. Possible environmental reservoirs include contaminated water sources. Serological tests that measure specific H. pylori IgG antibodies can determine if a person has been infected although these methods do have drawbacks and limitations

Shigella dysenteriae is a facultative anaerobic, Gram-negative rod from the family Enterobacteriaceae. S. dysenteriae is primarily a human pathogen, as are all Shigellae. The disease has infected masses, particularly in close living quarters, such as refugee camps. S. dysenteriae type 1 (Sd1) is the only cause of epidemic dysentery. The Shiga bacillus is the most virulent of the four serogroups of Shigella

Clostridium difficile, or C. difficile, a gram positive anaerobic bacterium, is the major causative agent of colitis and diarrhoea that can occur following antibiotic intake. C. difficile infection is one of the most common hospital acquired infections. When C. difficile colonize the gut, they release two potent toxins, toxin A and toxin B, which bind to certain receptors in the lining of the colon and ultimately cause diarrhoea and inflammation of the large intestine

Cryptosporidium is a small protozoan parasite, measuring about 3-5 µm. It lives on (or just under) the surface of the cells lining the small intestine, reproduces asexually, and oocysts are passed in the faeces. Transmission of the infection occurs via the oocysts. Many human infections have been traced to the contamination of drinking water with oocysts from agricultural "run-off" (i.e., drainage from pastures), so it is considered a zoonosis. The most common symptom of cryptosporidiosis is watery diarrhoea; other symptoms include stomach cramps or pain, fever, nausea and vomiting. In persons with healthy immune systems, symptoms usually last about 1 to 2 weeks. Cryptosporidiosis is now recognized as an important opportunisitic infection, especially in immunocompromised hosts

Herpes simplex type 1 (HSV-1) belongs to a family that includes HSV-2, Epstein-Barr virus (EBV) and Varicella zoster (chicken pox) virus amongst others. HSV-1 and HSV-2 are extremely difficult to distinguish from each other. Members of this family have a characteristic virion structure. The double stranded DNA genome is contained within an icosahedral capsid embedded in a proteinaceous layer (tegument) and surrounded by a lipid envelope, derived from the nuclear membrane of the last host, which is decorated with virus-specific glycoproteins spikes. These viruses are capable of entering a latent phase where the host shows no visible sign of infection and levels of infectious agent become very low. During the latent phase the viral DNA is integrated into the genome of the host cell

Plays an important role in the maintenance of intestinal epithelial homeostasis and the promotion of mucosal healing. Promotes VEGF-dependent neovascularization (By similarity). Contributes to phagocytic removal of apoptotic cells in many tissues. Specific ligand for the alpha-v/beta-3 and alpha-v/beta-5 receptors. Also binds to phosphatidylserine-enriched cell surfaces in a receptor-independent manner. Zona pellucida-binding protein which may play a role in gamete interaction. Binds specifically to rotavirus and inhibits its replication.Medin is the main constituent of aortic medial amyloid.  

Hepatitis B Virus Core Antigen (HBcAg) is part of the infectious virion containing an inner "core particle" enclosing the viral genome. The icosahedral core particle contains 180 or 240 copies of the core protein. HBcAg is one of the three major clinical antigens of hepatitis B virus but disappears early in the course of infection. The hepatitis B virus core antigen (HBcAg) is a highly immunogenic subviral particle and functions as both a T-cell-dependent and a T-cell-independent antigen. Therefore, HBcAg may be a promising candidate target for therapeutic vaccine control of chronic HBV infection

Hepatitis B Virus Core Antigen (HBcAg) is part of the infectious virion containing an inner "core particle" enclosing the viral genome. The icosahedral core particle contains 180 or 240 copies of the core protein. HBcAg is one of the three major clinical antigens of hepatitis B virus but disappears early in the course of infection. The hepatitis B virus core antigen (HBcAg) is a highly immunogenic subviral particle and functions as both a T-cell-dependent and a T-cell-independent antigen. Therefore, HBcAg may be a promising candidate target for therapeutic vaccine control of chronic HBV infection

Any of various slender, threadlike nematode worms of the superfamily Filarioidea that are parasitic in vertebrates and are often transmitted as larvae by mosquitos and other biting insects. The adult form lives in the blood and lymphatic tissues, causing inflammation and obstruction that can lead to elephantiasis

Klebsiella is a genus of non-motile, Gram-negative, Oxidase-negative bacteria with a prominent polysaccharide-based capsule. Frequent human pathogens, Klebsiella organisms can lead to a wide range of disease states, notably pneumonia, urinary tract infections, septicemia, Ankylosing spondylitis, and soft tissue infections. Klebsiella pneumoniae is clinically the most important member of the Klebsiella genus of Enterobacteriaceae. New antibiotic resistant strains of K. pneumoniae are appearing, and it is increasingly found as a nosocomial infection

Ricinus communis agglutinin 60(RCA60) is an extremely toxic glycoprotein consisting of two disulfide-linked chains of about 28,000 daltons and 32,000 daltons, termed A and B chain, respectively. The B chain can bind to cell surfaces via galactose or N-acetylgalactosamine residues of membrane glycoconjugates and facilitates the transport of the lectin into the cell. The A chain has an enzyme activity which can catalytically block protein synthesis and is so toxic that only a single molecule of A chain is required to kill a cell. Alone, the A chain is incapable of entering the cell and is thus not toxic. The A chain can be separated from the B chain and then linked by a cleavable disulfide bond to other proteins, such as antibodies. These antibody-toxin hybrid molecules can be used to kill specific cells with the appropriate antigenic determinant exposed, such as tumor markers on surfaces of malignant cells

Clostridium botulinum neurotoxins are zinc-dependent proteases that block the release of acetylcholine from peripheral cholinergic nerve endings by targeting specific membrane proteins including synaptosomal-associated proteins (SNAP), vesicle-associated membrane proteins (VAMP), and syntaxins. Neurotoxin A is characteristically associated with human botulism and known to target and hydrolyse the 197-Gln-|-Arg-198 bond of SNAP-25