Gaffkaemia (gaffkemia in

American English American English, sometimes called United States English or U.S. English, is the set of variety (linguistics), varieties of the English language native to the United States. English is the Languages of the United States, most widely spoken lan ...

) is a

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...

l disease of

lobster Lobsters are a family (biology), family (Nephropidae, Synonym (taxonomy), synonym Homaridae) of marine crustaceans. They have long bodies with muscular tails and live in crevices or burrows on the sea floor. Three of their five pairs of legs ...

s, caused by the

Gram-positive In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. Gram-positive bacte ...

lactic acid bacterium Lactobacillales are an order of gram-positive, low-GC, acid-tolerant, generally nonsporulating, nonrespiring, either rod-shaped (bacilli) or spherical (cocci) bacteria that share common metabolic and physiological characteristics. These bact ...

''Aerococcus viridans'' var. ''homari''.

Discovery

Gaffkaemia was first discovered in 1947 in

American lobster The American lobster (''Homarus americanus'') is a species of lobster found on the Atlantic Ocean, Atlantic coast of North America, chiefly from Labrador to New Jersey. It is also known as Atlantic lobster, Canadian lobster, true lobster, norther ...

s (''Homarus americanus'') in a holding tank in

Maine Maine () is a state in the New England and Northeastern regions of the United States. It borders New Hampshire to the west, the Gulf of Maine to the southeast, and the Canadian provinces of New Brunswick and Quebec to the northeast and north ...

. It was originally described as "''Gaffkya homari''" by Hitcher and Snieszko, but the genus name ''Gaffkya'' was rejected in 1971, and the gaffkaemia bacterium was recognised as a subspecies or variety of ''

Aerococcus viridans ''Aerococcus viridans'' is a member of the bacterial genus ''Aerococcus''. It is a causative agent of gaffkaemia Gaffkaemia (gaffkemia in American English) is a bacterial disease of lobsters, caused by the Gram-positive lactic acid bacterium ' ...

'' by Kelly and Evans in 1974.

Effects

The effects of gaffkaemia infection include

lethargy Lethargy is a state of tiredness, sleepiness, weariness, fatigue, sluggishness or lack of energy. It can be accompanied by depression, decreased motivation, or apathy. Lethargy can be a normal response to inadequate sleep, overexertion, overwo ...

(typically seen as a drooping tail),

anorexia Anorexia nervosa, often referred to simply as anorexia, is an eating disorder characterized by low weight, food restriction, body image disturbance, fear of gaining weight, and an overpowering desire to be thin. ''Anorexia'' is a term of Gre ...

and a pink colour on the ventral side of the

abdomen The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso. ...

, 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

appendage An appendage (or outgrowth) is an external body part, or natural prolongation, that protrudes from an organism's body. In arthropods, an appendage refers to any of the homologous body parts that may extend from a body segment, including anten ...

s. The effects of gaffkaemia are slowed by low temperatures, such that death can occur within two days of infection at , but can take over 60 days at . As few as five bacteria can lead to clinical disease. When they enter the host, the bacteria colonise the

heart The heart is a muscular organ in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon dioxide t ...

and

hepatopancreas The hepatopancreas, digestive gland or midgut gland is an organ of the digestive tract of arthropods and molluscs. It provides the functions which in mammals are provided separately by the liver and pancreas, including the production of digestive ...

. They may be engulfed by

phagocytosis Phagocytosis () is the process by which a cell uses its plasma membrane to engulf a large particle (≥ 0.5 μm), giving rise to an internal compartment called the phagosome. It is one type of endocytosis. A cell that performs phagocytosis is ...

into the lobster's blood cells, but continue to survive within the blood cells, feeding on the

cytoplasm In cell biology, the cytoplasm is all of the material within a eukaryotic cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. The ...

. The lobster's blood cell count drops, and the infection develops into

septicaemia Sepsis, formerly known as septicemia (septicaemia in British English) or blood poisoning, is a life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. This initial stage is follo ...

. The stores of

glycogen Glycogen is a multibranched polysaccharide of glucose that serves as a form of energy storage in animals, fungi, and bacteria. The polysaccharide structure represents the main storage form of glucose in the body. Glycogen functions as one o ...

in the hepatopancreas become depleted, concentrations of

glucose Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, using ...

and

lactic acid Lactic acid is an organic acid. It has a molecular formula . It is white in the solid state and it is miscible with water. When in the dissolved state, it forms a colorless solution. Production includes both artificial synthesis as well as natu ...

in the blood drop, and concentrations of

adenosine triphosphate Adenosine triphosphate (ATP) is an organic compound that provides energy to drive many processes in living cells, such as muscle contraction, nerve impulse propagation, condensate dissolution, and chemical synthesis. Found in all known forms of ...

muscle Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscl ...

s also fall. In a severe infection, the ability of the lobster's blood pigment

haemocyanin Hemocyanins (also spelled haemocyanins and abbreviated Hc) are proteins that transport oxygen throughout the bodies of some invertebrate animals. These metalloproteins contain two copper atoms that reversibly bind a single oxygen molecule (O2) ...

to carry

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...

may be reduced by up to 50%.

Diagnosis

The classical method of

diagnosis Diagnosis is the identification of the nature and cause of a certain phenomenon. Diagnosis is used in many different disciplines, with variations in the use of logic, analytics, and experience, to determine " cause and effect". In systems engin ...

is to culture aliquots of

haemolymph Hemolymph, or haemolymph, is a fluid, analogous to the blood in vertebrates, that circulates in the interior of the arthropod (invertebrate) body, remaining in direct contact with the animal's tissues. It is composed of a fluid plasma in which ...

in phenylethyl alcohol broth. Cultures containing ''A. viridans'' var. ''homari'' change colour from purple to yellow, and form tetrads of

cocci A coccus (plural cocci) is any bacterium or archaeon that has a spherical, ovoid, or generally round shape. Bacteria are categorized based on their shapes into three classes: cocci (spherical-shaped), bacillus (rod-shaped) and spiral ( of whi ...

. 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.

Virulence

Gaffkaemia is

enzootic Enzootic is the non-human equivalent of endemic and means, in a broad sense, "belonging to" or "native to", "characteristic of", or "prevalent in" a particular geography, race, field, area, or environment; native to an area or scope. It also has t ...

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

, and causes little harm to wild populations of ''H. americanus''. In the European or common lobster, ''

Homarus gammarus ''Homarus gammarus'', known as the European lobster or common lobster, is a species of lobster, clawed lobster from the eastern Atlantic Ocean, Mediterranean Sea and parts of the Black Sea. It is closely related to the American lobster, ''H.&nbs ...

'', however, it is far more destructive. European lobsters held in the same tanks as American lobsters can be killed within days. A number of other crustacean species can be infected with ''A. v.'' var. ''homari'', but do not develop severe disease. They include the

shrimp Shrimp are crustaceans (a form of shellfish) with elongated bodies and a primarily swimming mode of locomotion – most commonly Caridea and Dendrobranchiata of the decapod order, although some crustaceans outside of this order are refer ...

'' Pandalus platyceros'', and the crabs '' Cancer borealis'', '' Cancer irroratus'', ''

Metacarcinus magister The Dungeness crab (''Metacarcinus magister'') is a species of crab inhabiting eelgrass beds and water bottoms along the west coast of North America. It typically grows to across the carapace and is a popular seafood. Its common name comes from ...

'', ''

Libinia emarginata ''Libinia emarginata'', the portly spider crab, common spider crab or nine-spined spider crab, is a species of stenohaline crab that lives on the Atlantic coast of North America. Distribution ''Libinia emarginata'' occurs from Nova Scotia to th ...

'', ''

Chionoecetes opilio ''Chionoecetes opilio'', a species of snow crab, also known as opilio crab or opies, is a predominantly epifaunal crustacean native to shelf depths in the northwest Atlantic Ocean and north Pacific Ocean. It is a well-known commercial species of ...

'' and ''

Chaceon quinquedens ''Chaceon quinquedens'', commonly known as the red deep-sea crab, but sold as Atlantic deep sea red crab, or simply Atlantic red crab or red crab is a crab that lives in the Atlantic Ocean off the East Coast of the United States and Canada, fro ...

''.

Spiny lobster Spiny lobsters, also known as langustas, langouste, or rock lobsters, are a family (Palinuridae) of about 60 species of achelate crustaceans, in the Decapoda Reptantia. Spiny lobsters are also, especially in Australia, New Zealand, Ireland, So ...

s appear to be either immune or resistant to gaffkaemia.

Control

The primary method for controlling the incidence of gaffkaemia is improved hygiene. Other measures include limiting damage to the

exoskeleton An exoskeleton (from Greek ''éxō'' "outer" and ''skeletós'' "skeleton") is an external skeleton that supports and protects an animal's body, in contrast to an internal skeleton (endoskeleton) in for example, a human. In usage, some of the ...

(preventing the bacterium's entry), reducing the water temperature, and reducing the stocking density.

Antibiotic An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of ...

s may be effective against the bacterium, but only

tetracycline Tetracycline, sold under various brand names, is an oral antibiotic in the tetracyclines family of medications, used to treat a number of infections, including Acne vulgaris, acne, cholera, brucellosis, plague (disease), plague, malaria, and sy ...

is currently approved by the U.S

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respon ...

for use in American lobsters.

References