Enfermedad del Agua Fría

Tambien conocido como: Fin Rot — Tail Rot — Peduncle Disease — Síndrome del Alevin de Trucha Arcoiris

Causado por: Flavobacterium psychrophilum previamente conocido como: Cytophaga psychrophila — Flexibacter psychrophilus

Introducción

Cold water Disease in an ayu (Plecoglossus altivelis altivelis). Wikimedia Commons

Flavobacterium psychrophilum es una bacteria gram-negativa rod shaped pathogen, que causa Enfermedad del Agua Fría (EAF) en peces salmónidos. La enfermedad occurre tipicamente a temperaturas demenos de 13⁰C, and is most serious and prevalent below 10⁰C.

This disease is not zoonotic and poses no public health risk.

Distribución

CWD is common in any area where water temperatures are consistently below 15⁰C. This includes América del Norte, el Reino Unido, Europa y partes de Oceania.

Asymptomatic carrier fish and contaminated water provide reservoirs for disease. Transmission is mainly horizontal from these sources. Vertical transmission is also possible, via ovarian fluid, milt, egg surfaces and mucus.^[1] Eggs can also be experimentally contaminated and infected.

Especies Susceptibles

Most fishes worldwide are susceptible and the organism is ubiquitous.

Especies de salmónidos cultivados son afectados lo más frecuentes. Peces susceptibles incluyen: brook trout, rainbow trout, brown trout, lake trout, walleye, whitefish, carp, dace and suckers.

Signos Clínicos

Fish infected with typical CWD have external skin lesions, often on the dorsum, lose their fins and may also have severe erosion of the caudal fin. Fins may appear dark, torn, split, ragged, frayed or have haemorrhagic red patches/spots visible. Affected fish are often lethargic and stop feeding.

Internal, systemic infection can also be a sequel of CWD.

In Rainbow Trout Fry Syndrome, acute disease is usual and mortality can approach 60% which is devastating in the commonly affected populations of tens of thousands of young fish. Shortly before death, fish are lethargic, have darkened skin, inappetance and demonstrate exopthalmos.

Salmonid fish can also acquire a chronic form of CWD characterised by erratic “corkscrew” swimming, blackened tails and spinal deformities.^[2] This may follow recovery from typical CWD.

Diagnóstico

Diagnosis is often presumed from history, clinical signs, pattern of mortality and water temperature etc, especially if the location has previously encountered CWD.

Cultures can be made from smears or samples of lesions and the organism cultured on reduced nutrient agar, e.g. cytophaga agar, forming yellow creamy non-adhered colonies in 2-4days.

Histologically, periostitis, osteitis, meningitis and ganglioneuritis may be observed. In chronic disease cases, bacterial cells can accumulate in the cranial and vertebral areas causing inflammation and cartilage necrosis which leads to the spinal deformities noted.

Tratamiento

Quaternary ammonium compounds can be delivered in a static bath or flow through system for infected adult fish and fry. Potassium permanganate, copper sulphate and hydrogen peroxide can be applied externally but they can be toxic at high concentrations.

Terramycin can be added to feed as an alternative for adults, fry and broodstock. This can also be used preventively. Some resistance is emerging however.

Control

Ensuring water is pathogen-free and that water hardening is completed effectively for eggs is imperative.

Prophylactic antibiotic use should be carefully considered before implementation due to emerging resistance.

Referencias

↑ Brown, L. L., Cox, W. T., Levine, R. P (1997) Evidence that the causal agent of bacterial cold-water disease Flavobacterium psychrophilum is transmitted within salmonid eggs. Diseases of Aquatic Organisms, 29(3):213-218
↑ Blazer, V., Stark, K., Starliper, C (1996) Unusual histologic manifestations of Flexibacter psychrophila in hatchery salmonids. In: 21st Annual Eastern Fish Health Workshop. Gloucester Point, Virginia, 5-6 September, 10

Starliper, C.E. and Schill, W.B. 2011. Flavobacterial Diseases: Coldwater Disease, Columnaris Disease, and Bacterial Gill Diseases. In: Fish Diseases and Disorders Volume 3: Viral, Bacterial and Fungal Infections, 2nd. Edition (eds. P.T.K. Woo and D.W. Bruno), CABI, Wallingford, UK, pp. 606-631

Enfermedad del Agua Fría Entorno de Enseñanza Virtual
Flashcards Comprobar tus conocimientos utilizando preguntas de tipo Flashcard	Cold Water Disease Flashcards

Este artículo fue originalmente de The Animal Health & Production Compendium (AHPC) publicado en el web por CABI.

Hoja(s) de datos utilizados: cold-water disease and Flavobacterium psychrophilum el 10 July 2011

[1] Brown, L. L., Cox, W. T., Levine, R. P (1997) Evidence that the causal agent of bacterial cold-water disease Flavobacterium psychrophilum is transmitted within salmonid eggs. Diseases of Aquatic Organisms, 29(3):213-218

[2] Blazer, V., Stark, K., Starliper, C (1996) Unusual histologic manifestations of Flexibacter psychrophila in hatchery salmonids. In: 21st Annual Eastern Fish Health Workshop. Gloucester Point, Virginia, 5-6 September, 10

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