Phytotherapy of ulcerative dermatitis induced by Aeromonas hydrophila infection in goldfish ( Carassius auratus ).

Goldfish ( Carassius auratus ) weighing 13 +/- 2 g were administered intramuscularly a sublethal dose (1.8 x 10 3 cfu/ml) of Aeromonas hydrophila to induce ulcerative dermatitis. On day 3 and day 6 after infection the fish were dip-treated (for 5 min/day) with a tri-herbal concoction of Curcuma longa, Ocimum sanctum and Azadirachta indica (1%). The LD 50 value was recorded at a concentration of 2.3 x 10 4 between 30 and 36 days after infection. In the infected untreated group the cumulative mortality was higher, while in the early-treated group (day 3) there was no mortality. In the late-treated group (6th day) the mortality increased to 23.3% on day 36. In the infected group the size of ulcers progressively increased from 43.3% of the body length on day 18 to 86.7% on day 36. In the early-treated fish the size of ulcers was 23.3% of the body length on day 18; by day 36 after treatment the ulcer had completely healed. In contrast, there was only a moderate recovery in the late-treated group. From the results it can be concluded that early tri-herbal treatment ensures successful recovery from ulcerative dermatitis induced by A. hydrophila .

Loktanella pyoseonensis sp. nov., isolated from beach sand, and emended description of the genus Loktanella.

A novel Gram-stain-negative, aerobic, heterotrophic, obligately halophilic bacterium, designated strain JJM85(T), was isolated from beach sand in Jeju, Republic of Korea. Cells were rod-shaped and motile by means of flagella; colonies were pink, convex and smooth with an entire edge. The organism grew at pH 5.0-10.0 and 4-30 degrees C. Phylogenetic analysis based on 16S rRNA gene sequences showed that the organism belonged to the genus Loktanella of the class Alphaproteobacteria and formed a tight cluster with the type strain of Loktanella hongkongensis (96.0 % sequence similarity). The DNA G+C content and fatty acid profile of the novel strain supported affiliation with the genus Loktanella. However, the novel strain could be differentiated clearly from members of this genus by cell motility, some physiological properties and low 16S rRNA gene sequence similarity (93.1-96.0 %). On the basis of the polyphasic data presented here, strain JJM85(T) is considered to represent a novel species of the genus Loktanella, for which the name Loktanella pyoseonensis sp. nov. is proposed; the type strain is JJM85(T) (=KCTC 22372(T) =DSM 21424(T)).

Effectiveness of chemotherapeutants against scuticociliate Philasterides dicentrarchi, a parasite of olive flounder.

The histophagous scuticociliate Philasterides dicentrarchi causes fatal scuticociliatosis in farmed olive flounder Paralichthys olivaceus. The average monthly prevalence of scuticociliatosis with P. dicentrarchi infections was very high from May to July (40+/-3 to 79+/-2%) in olive flounder at farms of Jeju Island, South Korea, from 2000 to 2004. The prevalence of mixed infection along with Vibrio spp. infection was higher (49+/-8%) than that of scuticociliatosis alone. To date no effective control measure for P. dicentrarchi infection has been described and large economic losses continue. In the present study 3 chemotheraputants (formalin, hydrogen peroxide and Jenoclean) were used. Among these, bath treatment with Jenoclean at a low concentration of 50ppm proved effective; the results were confirmed with in vitro motility assessments and morphological changes in P. dicentrarchi. A similar trend was noted following hydrogen peroxide treatment. However, formalin was only moderately effective at this concentration. Therefore, hydrogen peroxide and Jenoclean are the promising compounds effective at low concentrations with short application time.

Histopathological changes of Korea cultured olive flounder, Paralichthys olivaceus due to scuticociliatosis caused by histophagous scuticociliate, Philasterides dicentrarachi.

Recently, mass mortality due to histophagous scuticociliate, Philasterides dicentrarachi in olive flounder, Paralichthys olivaceus occurred in aquaculture farms of Jeju Island, South Korea. We have artificially induced infection through immersion on day 12, the density of ciliates slowly decreased in the experimental tanks; on day 28 to 2300cells/ml in 3cm group and 1800cells/ml in 5cm group. The survival rate of P. olivaceus on days 24 and 28 of infection in the 3cm group was decreased to 4 and 6, respectively; however, no mortality was recorded in the 5cm group. In the control group 100% survival in the chosen period of both groups occurred except in the 3cm group whereas on days 24 and 28 the death rate was 1 and 2, respectively. Many ciliates with ingested red blood cells were observed in the gills, skeletal muscle, skin, fins and brains of infected flounder. The parasites were also observed in the lamina propria of the digestive tract, pharynx, peritoneal fluid, cerebrospinal fluid and cornea. Histopathological and inflammatory changes were characterized by swelling and generalized erythema and muscle tissue necrosis. Affected fish showed varying levels of tissue damage including severe epidermal and dermal necrotic lesions. Loss of scales, appearance of bleached spots that coalesced to form brownish patches, haemorrhagic and severe dermal necrotic lesions were the major clinico-pathological manifestations. The parasite was also seen distributed extensively in the entire brain causing widespread nerve necrosis after a prolonged period of infection. These results appear to support the hypothesis that the P. dicentrarchi may be penetrating via the gills or the skin, and then travel via the bloodstream to other parts of the body, including the body cavity.