| Aerococcus viridans var. homari | |
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| Subspecies: | A. v. var. homari |
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| Aerococcus viridans var. homari (Hitchner & Snieszko, 1947) | |
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Gaffkaemia (gaffkemia in American English) is a bacterial disease of lobsters, caused by the Gram-positive lactic acid bacterium Aerococcus viridans var. homari.
Gaffkaemia was first discovered in 1947 in American lobsters (Homarus americanus) in a holding tank in Maine. [1] It was originally described as "Gaffkya homari" by Hitcher and Snieszko, but the genus name Gaffkya was rejected in 1971, [2] [3] and the gaffkaemia bacterium was recognised as a subspecies or variety of Aerococcus viridans by Kelly and Evans in 1974. [4]
The effects of gaffkaemia infection include lethargy (typically seen as a drooping tail), [5] anorexia and a pink colour on the ventral side of the abdomen, which gives the disease its alternative common name of red tail disease. When lobsters are moribund, they may lie on their sides, and frequently lose appendages. [6] The effects of gaffkaemia are slowed by low temperatures, such that death can occur within two days of infection at 20 °C (68 °F), but can take over 60 days at 3 °C (37 °F). [6]
As few as five bacteria can lead to clinical disease. When they enter the host, the bacteria colonise the heart and hepatopancreas. [6] They may be engulfed by phagocytosis into the lobster's blood cells, but continue to survive within the blood cells, feeding on the cytoplasm. The lobster's blood cell count drops, and the infection develops into septicaemia. [6] The stores of glycogen in the hepatopancreas become depleted, concentrations of glucose and lactic acid in the blood drop, and concentrations of adenosine triphosphate in muscles also fall. [6] In a severe infection, the ability of the lobster's blood pigment haemocyanin to carry oxygen may be reduced by up to 50%. [6]
The classical method of diagnosis is to culture aliquots of haemolymph in phenylethyl alcohol broth. Cultures containing A. viridans var. homari change colour from purple to yellow, and form tetrads of cocci. To reduce the four-day waiting time needed for diagnosis, a method using the indirect fluorescent antibody technique (IFAT) was developed, and, more recently, PCR-based methods have been developed. [6]
Gaffkaemia is enzootic in North America, and causes little harm to wild populations of H. americanus. In the European or common lobster, Homarus gammarus , however, it is far more destructive. European lobsters held in the same tanks as American lobsters can be killed within days. [7] A number of other crustacean species can be infected with A. v. var. homari, but do not develop severe disease. They include the shrimp Pandalus platyceros , and the crabs Cancer borealis , Cancer irroratus , Metacarcinus magister , Libinia emarginata , Chionoecetes opilio and Chaceon quinquedens . [6] Spiny lobsters appear to be either immune or resistant to gaffkaemia. [6]
The primary method for controlling the incidence of gaffkaemia is improved hygiene. [6] Other measures include limiting damage to the exoskeleton (preventing the bacterium's entry), reducing the water temperature, and reducing the stocking density. [6] Antibiotics may be effective against the bacterium, but only tetracycline is currently approved by the U.S. Food and Drug Administration for use in American lobsters. [6]
The immune system is a network of biological processes that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to parasitic worms, as well as cancer cells and objects such as wood splinters, distinguishing them from the organism's own healthy tissue. Many species have two major subsystems of the immune system. The innate immune system provides a preconfigured response to broad groups of situations and stimuli. The adaptive immune system provides a tailored response to each stimulus by learning to recognize molecules it has previously encountered. Both use molecules and cells to perform their functions.
A human pathogen is a pathogen that causes disease in humans.
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.
A biofilm comprises any syntrophic consortium of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular polymeric substances (EPSs). The cells within the biofilm produce the EPS components, which are typically a polymeric conglomeration of extracellular polysaccharides, proteins, lipids and DNA. Because they have three-dimensional structure and represent a community lifestyle for microorganisms, they have been metaphorically described as "cities for microbes".
Helicobacter pylori, previously known as Campylobacter pylori, is a gram-negative, microaerophilic, spiral (helical) bacterium usually found in the stomach. Its helical shape is thought to have evolved in order to penetrate the mucoid lining of the stomach and thereby establish infection. The bacterium was first identified in 1982 by the Australian doctors Barry Marshall and Robin Warren. H. pylori has been associated with cancer of the mucosa-associated lymphoid tissue in the stomach, esophagus, colon, rectum, or tissues around the eye, and of lymphoid tissue in the stomach.
Lactic acidosis is a medical condition characterized by a build-up of lactate in the body, with formation of an excessively low pH in the bloodstream. It is a form of metabolic acidosis, in which excessive acid accumulates due to a problem with the body's oxidative metabolism.
The American lobster is a species of lobster found on the Atlantic coast of North America, chiefly from Labrador to New Jersey. It is also known as Atlantic lobster, Canadian lobster, true lobster, northern lobster, Canadian Reds, or Maine lobster. It can reach a body length of 64 cm (25 in), and a mass of over 20 kilograms (44 lb), making it not only the heaviest crustacean in the world, but also the heaviest of all living arthropod species. Its closest relative is the European lobster Homarus gammarus, which can be distinguished by its coloration and the lack of spines on the underside of the rostrum. American lobsters are usually bluish green to brown with red spines, but several color variations have been observed.
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.
Mycoplasma pneumoniae is a very small bacterium in the class Mollicutes. It is a human pathogen that causes the disease mycoplasma pneumonia, a form of atypical bacterial pneumonia related to cold agglutinin disease. M. pneumoniae is characterized by the absence of a peptidoglycan cell wall and resulting resistance to many antibacterial agents. The persistence of M. pneumoniae infections even after treatment is associated with its ability to mimic host cell surface composition.
Lactococcus lactis is a gram-positive bacterium used extensively in the production of buttermilk and cheese, but has also become famous as the first genetically modified organism to be used alive for the treatment of human disease. L. lactis cells are cocci that group in pairs and short chains, and, depending on growth conditions, appear ovoid with a typical length of 0.5 - 1.5 µm. L. lactis does not produce spores (nonsporulating) and are not motile (nonmotile). They have a homofermentative metabolism, meaning they produce lactic acid from sugars. They've also been reported to produce exclusive L-(+)-lactic acid. However, reported D-(−)-lactic acid can be produced when cultured at low pH. The capability to produce lactic acid is one of the reasons why L. lactis is one of the most important microorganisms in the dairy industry. Based on its history in food fermentation, L. lactis has generally recognized as safe (GRAS) status, with few case reports of it being an opportunistic pathogen.
Homarus gammarus, known as the European lobster or common lobster, is a species of clawed lobster from the eastern Atlantic Ocean, Mediterranean Sea and parts of the Black Sea. It is closely related to the American lobster, H. americanus. It may grow to a length of 60 cm (24 in) and a mass of 6 kilograms (13 lb), and bears a conspicuous pair of claws. In life the lobsters are blue, only becoming "lobster red" on cooking. Mating occurs in the summer, producing eggs which are carried by the females for up to a year before hatching into planktonic larvae. Homarus gammarus is a highly esteemed food, and is widely caught using lobster pots, mostly around the British Isles.
An antimicrobial is an agent that kills microorganisms (microbicide) or stops their growth. Antimicrobial medicines can be grouped according to the microorganisms they act primarily against. For example, antibiotics are used against bacteria, and antifungals are used against fungi. They can also be classified according to their function. The use of antimicrobial medicines to treat infection is known as antimicrobial chemotherapy, while the use of antimicrobial medicines to prevent infection is known as antimicrobial prophylaxis.
Chlamydia felis is a Gram-negative, obligate intracellular bacterial pathogen that infects cats. It is endemic among domestic cats worldwide, primarily causing inflammation of feline conjunctiva, rhinitis and respiratory problems. C. felis can be recovered from the stomach and reproductive tract. Zoonotic infection of humans with C. felis has been reported. Strains FP Pring and FP Cello have an extrachromosomal plasmid, whereas the FP Baker strain does not. FP Cello produces lethal disease in mice, whereas the FP Baker does not. An attenuated FP Baker strain, and an attenuated 905 strain, are used as live vaccines for cats.
The Aerococcaceae are a family of Gram-positive lactic acid bacteria, including the bacterium that causes gaffkaemia in lobsters.
Leptospira interrogans is a species of obligate aerobic spirochaete bacteria shaped like a corkscrew with hooked and spiral ends. L. interrogans is mainly found in warmer tropical regions. The bacteria can live for weeks to months in the ground or water. Leptospira is one of the genera of the spirochaete phylum that causes severe mammalian infections. This species is pathogenic to some wild and domestic animals, including pet dogs. It can also spread to humans through abrasions on the skin, where infection can cause flu-like symptoms with kidney and liver damage. Human infections are commonly spread by contact with contaminated water or soil, often through the urine of both wild and domestic animals. Some individuals are more susceptible to serious infection, including farmers and veterinarians who work with animals.
Biopreservation is the use of natural or controlled microbiota or antimicrobials as a way of preserving food and extending its shelf life. The biopreservation of food, especially utilizing lactic acid bacteria (LAB) that are inhibitory to food spoilage microbes, has been practiced since early ages, at first unconsciously but eventually with an increasingly robust scientific foundation. Beneficial bacteria or the fermentation products produced by these bacteria are used in biopreservation to control spoilage and render pathogens inactive in food. There are a various modes of action through which microorganisms can interfere with the growth of others such as organic acid production, resulting in a reduction of pH and the antimicrobial activity of the un-dissociated acid molecules, a wide variety of small inhibitory molecules including hydrogen peroxide, etc. It is a benign ecological approach which is gaining increasing attention.
Aerococcus is a genus in the phylum Bacillota (Bacteria). The genus was first identified in 1953 from samples of air and dust as a catalase-negative, gram-positive coccus that grew in small clusters. They were subsequently found in hospital environments and meat-curing brines. It has been difficult to identify as it resembles alpha-hemolytic Streptococcus on blood agar plates and is difficult to identify by biochemical means. Sequencing of 16S rRNA has become the gold standard for identification, but other techniques such as MALDI-TOF have also been useful for identifying both the genus and species.
Aerococcus urinae is a Gram-positive bacterium associated with urinary tract infections.
Lacticaseibacillus paracasei is a gram-positive, homofermentative species of lactic acid bacteria that are commonly used in dairy product fermentation and as probiotic cultures. Lc. paracasei is a bacterium that operates by commensalism. It is commonly found in many human habitats such as human intestinal tracts and mouths as well as sewages, silages, and previously mentioned dairy products. The name includes morphology, a rod-shaped bacterium with a width of 2.0 to 4.0μm and length of 0.8 to 1.0μm.
Aerococcus viridans is a member of the bacterial genus Aerococcus. It is a causative agent of gaffkaemia, a disease of lobsters, and is used as a commercial source for lactate oxidase.
