Streptococcus is a genus of gram-positive coccus or spherical bacteria that belongs to the family Streptococcaceae, within the order Lactobacillales, in the phylum Bacillota. Cell division in streptococci occurs along a single axis, so as they grow, they tend to form pairs or chains that may appear bent or twisted. This differs from staphylococci, which divide along multiple axes, thereby generating irregular, grape-like clusters of cells. Most streptococci are oxidase-negative and catalase-negative, and many are facultative anaerobes.
Escherichia coli O157:H7 is a serotype of the bacterial species Escherichia coli and is one of the Shiga-like toxin–producing types of E. coli. It is a cause of disease, typically foodborne illness, through consumption of contaminated and raw food, including raw milk and undercooked ground beef. Infection with this type of pathogenic bacteria may lead to hemorrhagic diarrhea, and to kidney failure; these have been reported to cause the deaths of children younger than five years of age, of elderly patients, and of patients whose immune systems are otherwise compromised.
Shigella is a genus of bacteria that is Gram-negative, facultatively anaerobic, non–spore-forming, nonmotile, rod-shaped, and is genetically closely related to Escherichia. The genus is named after Kiyoshi Shiga, who discovered it in 1897.
Virulence is a pathogen's or microorganism's ability to cause damage to a host.
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. 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. 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.
Lactococcus is a genus of lactic acid bacteria that were formerly included in the genus Streptococcus Group N1. They are known as homofermenters meaning that they produce a single product, lactic acid in this case, as the major or only product of glucose fermentation. Their homofermentative character can be altered by adjusting environmental conditions such as pH, glucose concentration, and nutrient limitation. They are gram-positive, catalase-negative, non-motile cocci that are found singly, in pairs, or in chains. The genus contains strains known to grow at or below 7˚C.
Yersinia enterocolitica is a Gram-negative, rod-shaped bacterium, belonging to the family Yersiniaceae. It is motile at temperatures of 22–29°C (72–84°F), but becomes nonmotile at normal human body temperature. Y. enterocolitica infection causes the disease yersiniosis, which is an animal-borne disease occurring in humans, as well as in a wide array of animals such as cattle, deer, pigs, and birds. Many of these animals recover from the disease and become carriers; these are potential sources of contagion despite showing no signs of disease. The bacterium infects the host by sticking to its cells using trimeric autotransporter adhesins.
Myxobolus cerebralis is a myxosporean parasite of salmonids that causes whirling disease in farmed salmon and trout and also in wild fish populations. It was first described in rainbow trout in Germany in 1893, but its range has spread and it has appeared in most of Europe, the United States, South Africa, Canada and other countries from shipments of cultured and wild fish. In the 1980s, M. cerebralis was found to require a tubificid oligochaete to complete its life cycle. The parasite infects its hosts with its cells after piercing them with polar filaments ejected from nematocyst-like capsules. This infects the cartilage and possibly the nervous tissue of salmonids, causing a potentially lethal infection in which the host develops a black tail, spinal deformities, and possibly more deformities in the anterior part of the fish.
Infectious bursal disease (IBD), also known as Gumboro disease, infectious bursitis, and infectious avian nephrosis, is a highly contagious disease of young chickens and turkeys caused by infectious bursal disease virus (IBDV), characterized by immunosuppression and mortality generally at 3 to 6 weeks of age. The disease was first discovered in Gumboro, Delaware in 1962. It is economically important to the poultry industry worldwide due to increased susceptibility to other diseases and negative interference with effective vaccination. In recent years, very virulent strains of IBDV (vvIBDV), causing severe mortality in chicken, have emerged in Europe, Latin America, South-East Asia, Africa, and the Middle East. Infection is via the oro-fecal route, with affected birds excreting high levels of the virus for approximately 2 weeks after infection. The disease is easily spread from infected chickens to healthy chickens through food, water, and physical contact.
Aeromonas veronii is a Gram-negative, rod-shaped bacterium found in fresh water and in association with animals. It can be a pathogen of humans and a beneficial symbiont of leeches. In humans A. veronii can cause diseases ranging from wound infections and diarrhea to sepsis in immunocompromised patients. Humans treated with medicinal leeches after vascular surgery can be at risk for infection from A. veronii and are commonly placed on prophylactic antibiotics. Most commonly ciprofloxacin is used but there have been reports of resistant strains leading to infection. In leeches, this bacterium is thought to function in the digestion of blood, provision of nutrients, or preventing other bacteria from growing.
Aeromonas hydrophila is a heterotrophic, Gram-negative, rod-shaped bacterium mainly found in areas with a warm climate. This bacterium can be found in fresh or brackish water. It can survive in aerobic and anaerobic environments, and can digest materials such as gelatin and hemoglobin. A. hydrophila was isolated from humans and animals in the 1950s. It is the best known of the species of Aeromonas. It is resistant to most common antibiotics and cold temperatures and is oxidase- and indole-positive. Aeromonas hydrophila also has a symbiotic relationship as gut flora inside of certain leeches, such as Hirudo medicinalis.
Viral hemorrhagic septicemia (VHS) is a deadly infectious fish disease caused by Viral hemorrhagic septicemia virus. It afflicts over 50 species of freshwater and marine fish in several parts of the Northern Hemisphere. Different strains of the virus occur in different regions, and affect different species. There are no signs that the disease affects human health. VHS is also known as Egtved disease, and the virus as Egtved virus.
Dichelobacter nodosus, formerly Bacteroides nodosus, is a Gram-negative, obligate anaerobe of the family Cardiobacteriaceae. It has polar fimbriae and is the causative agent of ovine foot rot as well as interdigital dermatitis. It is the lone species in the genus Dichelobacter.
Aeromonas salmonicida is a pathogenic bacterium that severely impacts salmonid populations and other species. It was first discovered in a Bavarian brown trout hatchery by Emmerich and Weibel in 1894. Aeromonas salmonicida's ability to infect a variety of hosts, multiply, and adapt, make it a prime virulent bacterium. A. salmonicida is an etiological agent for furunculosis, a disease that causes sepsis, haemorrhages, muscle lesions, inflammation of the lower intestine, spleen enlargement, and death in freshwater fish populations. It is found worldwide with the exception of South America. The major route of contamination is poor water quality; however, it can also be associated stress factors such as overcrowding, high temperatures, and trauma. Spawning and smolting fish are prime victims of furunculosis due to their immunocompromised state of being.
Streptococcus iniae is a species of Gram-positive, sphere-shaped bacterium belonging to the genus Streptococcus. Since its isolation from an Amazon freshwater dolphin in the 1970s, S. iniae has emerged as a leading fish pathogen in aquaculture operations worldwide, resulting in over US$100M in annual losses. Since its discovery, S. iniae infections have been reported in at least 27 species of cultured or wild fish from around the world. Freshwater and saltwater fish including tilapia, red drum, hybrid striped bass, and rainbow trout are among those susceptible to infection by S. iniae. Infections in fish manifest as meningoencephalitis, skin lesions, and septicemia.
Edwardsiella tarda is a member of the family Hafniaceae. The bacterium is a facultatively anaerobic, small, motile, gram negative, straight rod with flagella. Infection causes Edwardsiella septicemia in channel catfish, eels, and flounder. Edwardsiella tarda is also found in largemouth bass and freshwater species such as rainbow trout. It is a zoonosis and can infect a variety of animals including fish, amphibians, reptiles, and mammals. Edwardsiella tarda has also been the cause of periodic infections for various animals within zoos. E. tarda has a worldwide distribution and can be found in pond water, mud, and the intestine of fish and other marine animals. It is spread by carrier animal feces.
Actinobacillus pleuropneumoniae, is a Gram-negative, facultative anaerobic, respiratory pathogen found in pigs. It was first reported in 1957, and was formally declared to be the causative agent of porcine pleuropneumonia in 1964. It was reclassified in 1983 after DNA studies showed it was more closely related to A. lignieresii.
Infectious pancreatic necrosis virus (IPNV) is a double-stranded RNA virus from the family Birnaviridae, in the genus Aquabirnavirus. Causing the highly infectious disease Infectious pancreatic necrosis, the virus primarily affects young salmonids resulting in high mortality, occasionally surpassing 90 percent in the early stages. IPNV or IPNV-like viruses have been isolated worldwide from at least 32 families of saltwater and freshwater salmonids and non-salmonids fish including salmon, flatfish, pike, eels and others. Other aquatic organisms infected include 11 molluscs and 4 species of crustaceans. Due to its wide host range and high mortality, the virus is of great concern to global aquaculture. In addition to persistence in hosts, IPNV is also perpetual in the environment, surviving across a range of conditions and capable of infecting fish with as little as 101TCID50/ml of the virus. Found in Europe, North America, South America, Africa, Asia, and Australia, the virus has led to significant losses in the mariculture of Atlantic salmon, brook trout, and rainbow trout.
Vaccine resistance is the evolutionary adaptation of pathogens to infect and spread through vaccinated individuals, analogous to antimicrobial resistance. It concerns both human and animal vaccines. Although the emergence of a number of vaccine resistant pathogens has been well documented, this phenomenon is nevertheless much more rare and less of a concern than antimicrobial resistance.
LG2 or variation, may refer to:
