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Vibriosis or bacterial disease, Penaeid bacterial septicemia, Penaeid vibriosis, Luminescent vibriosis, Red-leg disease, "sien dun" in Thai which translates to black splint, Sea gull syndrome or "Sindroma de gaviota" in Latin America.
Scientific name or taxonomic affiliation
Vibrio spp. (i.e., V. harveyi, V. vulnificus, V. anguillarum, V. splendidus, V. alginolyticus, V. nereis, V. parahaemolyticus, V. damsela, V. tubiashi, V. fluvialis). Other Gram negative, oxidase positive bacteria (i.e. Psuedomonas sp., Aeromonas sp. and Flavobacterium sp.) have also been isolated from shrimp with Vibrio sp. infections.
All cultured penaeids and cultured Macrobrachium rosenbergii are susceptible under stressful conditions.
Impact on the host
Anorexia and behavioural changes. Some species and strains of Vibrio cause the shrimp to be luminescent. Mortality ranges from insignificant to 100%, particularly in postlarvae and young juvenile shrimp. There is also concern over the appearance of antibiotic-resistant strains as reported for V. harveyi that cause mass mortality of cultured shrimp.
Gross Observations: Vary with the type of infection - black or brown cuticular lesions, opacity of musculature, tough and black branching filaments (up to 2 mm wide) in connective tissue of tail segments, black lymphoid (Oka) organ, melanization of appendage tips.
Wet Mounts: Large numbers of bacteria in the heamolymph.
Histology: Significant necrosis and inflammation especially in the Oka/lymphoid organ and frequently, but usually less severe, in the gills, heart, hepatopancreas and sometimes other tissues. Often there are rod shaped bacteria (usually slightly curved) within the tissues.
Culture: Isolate Vibrio spp. from tissue or haemolymph of moribund samples. The bacteria are not fastidious and will grow on a wide variety of nutrient agar media including the selective media Thiosulfate Citrate Bile Salts Agar (Lightner 1983). Detailed procedures and culture characteristics of several species of Vibrio were described by Lightner (1996).
Methods of Control
Maintain adequate water quality with low bacterial biomass, a stable phytoplankton bloom and a proper feeding program. Sterilize or filter recirculated water. Routinely monitor shrimp and pond for early diagnosis of a problem. Avoid temperature extremes or rapid variation in temperature, handling, overcrowding, and other stressors. Infections opportunistic and probably result from poor husbandry; may be secondary to other disease processes. In Thailand (and probably at other locations) the incidence of antibiotic resistance in the isolated strains was high.
HEALTH MANAGEMENT & DISEASE CONTROL INDEX
Hepatopancreatic parvo-like virus (HPV) . Reo-like virus (REO) . Lymphoid organ vacuolization virus (LOVV) . Taura Syndrome Virus (TSV) . Rhabdovirus of Penaeid Shrimp (RPS) . White Spot Syndrome Virus (WSSV) . Infectious hypodermal and hematopoietic virus (IHHNV) . Baculovirus penaei (BP)
You are here . Epicommensal fouling disease (filementous bacteria) . Necrotizing Hepatopancreatitis (NHP) . Black spot disease (BSD) . Mycobacteriosis
Larval mycosis . Fusariosis
Haplosporidia . Gregarines . Cotton Disease
Black Gill Disease (BGD) Dissolved Oxygen Crisis Nitrogen Gas Bubble Disease