Vibriosis - Fish
Introduction
Vibriosis is one in every of the foremost rife fish diseases and is caused by bacterium happiness to the genus Vibrio. one in every of the foremost necessary strain is eubacterium anguillarum that is of major importance to malacopterygian fish culture trade and is additionally called Red cuss of eels. it's a gram negative recurvate and rod formed bacteria with one polar flagellum. alternative species (e.g. V. salmonicida) might have various polar flagella. V. anguillarum has been divided into 2 separate biotypes of that V. anguillarum genotype II has been renamed and classified as a brand new species eubacterium ordalii. It causes trauma septicemia and blood disorder.
Other members of the genus Vibrio are related to vibriosis outbreaks in fish and shellfish (molluscs and crustacean) and these include: V. salmonicida, V. damsela, V. vulnificus genotype II, V. tubiashii, V. carchariae, V. splendidus and V. pelagius.
Signalment
Vibrio anguillarum is found in cultivated and wild marine fish in shallow salt or salt water throughout late summer. The microorganism was thought to be unfold by contact with scavenging wild fish feeding round the farms however V. anguillarum, has been found within the food of cultivated and wild healthy fish
Outbreaks of vibriosis are seen in Pacific and Atlantic salmon, Trout, Turbot, stripy bass, Winter flounder, Cod, Red sea-bream, European and Japanese eel, Saithe (Pollachius Virens), Gilthead sea-bream, Sea mullet, Seriola, siluriform fish, Milkfish, Ayu, and genus Tilapia. It may have an effect on molluscs and crustacean together with European and Ostrea gigas, clam, lobster and shrimp.
Disease outbreaks will be influenced by water quality and temperature, the strain and virulence of the {vibrio|vibrion|eubacteria|eubacterium|true bacterium} bacteria and therefore the quantity of stress obligatory upon the fish.
Other species of eubacterium have an effect on a good vary of species for instance V. salmonicida primarily affects Alantic salmon and trout and causes cold water vibriosis, V. damsela affects metalworker species (Chromis punctipinnis), V. vulnificus conjointly called V. anguillicidacuases causes malady in eels.
Both V. vulnificus and V. damsela square measure animal disease. it's thought that the infection is caused from feeding contaminated raw or undercooked food, especially raw oysters. disorder and other people with liver diseases square measure at magnified risk.
Clinical Signs
Clinical signs of vibriosis square measure harm to intestines, body cavity, spleen and muscle, distended mucoid and death gut and petechiation, erosion and darkended colouration to the skin and fins. Changes to the eyes embody distension and cloudiness and periorbital swelling. White/grey lesions will be found on the intestines and spleen and in fry, hypertrophy will be seen.
V. damsela and V.vulnificus cause severe, progressive necrotizing infection in humans.
Distribution
Asia, North America and Europe together with outbreaks within the Britain.
Diagnosis
Presumptive diagnosing will be made up of clinical signs particularly characteristic red spots, swollen and dark lesions on the skin that bleed and ophthalmic changes; though some acute and severe cases die while not clinical signs. With V.anguillarum a lot of severe pathology is seen within the drizzling alimentary tract because the conditions become a lot of alkalescent. Most tissues square measure septic with no proof of body process.
Identification strategies embody a substance for presumptive identification, a sensitivity assay to filter discs fertile with a saturated resolution of the vibriostatic agent 0/129 (2,4-diamino-6,7-diisopropylteridine), nitrate reduction, presence of enzyme, enzyme and essential amino acid enzyme, reaction with being antibodies and antiflagellar serum, and hybridizing with specific 16S ribosomal RNA (rRNA) oligonucleotide
Vibrio species will be known victimisation being antibodies (MAbs).
V. vulnificus will be known victimisation AN assay for the erythrolysin and PCR. Pathology for V. ordalii tends to be a lot of localised to the muscle and areas of the malacopterygian skin, however may be found in loose animal tissue of the gills, throughout the channel and within the opening caeca.
V. salmonicida conjointly called trauma syndrome, show haemorrhaging within the covering close the inner organs and therefore the fish square measure anaemic and fry show splenamegaly, cataracts and os harm. Whereas V. damsela shows primarily ulcerations from zero.5-2cm in diameter and square measure defined by muscle lysis and histiocytes inside the derma and musculus of Chromis punctipinnis
Treatment
Fish will be treated with Polycillin, Chloromycetin, NegGram derivatives, nitrofurans, sulphonamides and trimethoprim. Drug resistant strains have appeared owing to in depth use of those chemicals.
Control
A formalin-killed V. anguillarium immunogen is on the market and may be administered via intraperitoneal injection, immersion or oral administration.
