• Journal of Aquaculture
• /
• v.20 no.4
• /
• pp.278-288
• /
• 2007

Shrimp culture in Korea had been rapidly developed during 1990's and the production of farmed shrimp reached 3,268 mt from 2,605 ha in 2001. However the shrimp production decreased to 2,368 mt in 2004 because of the mass mortality due to outbreak of white spot syndrome virus (WSSV). WSSV which is one of the most serious threats associated with cultured shrimp around the world has given the economic damages to shrimp culture industry every year since it was found from the shrimp ponds in the west coast of the South Korea in 1993. Various polyculture technologies of shrimp with shellfish, finfish or seaweeds have been implemented to reduce economic damages by mass mortalities of shrimp. Among them, the polyculture of shrimp with carnivorous fish can suppress or delay the viral outbreak of shrimp ponds because the fish may selectively eat the moribund shrimps infected by virus. To determine the selective predatory effect of river puffer Takifugu obscures on WSSV infected shrimp, postlarvae of Litopenaeus vannamei and Fenneropenaeus chinensis. One-year old river puffers were stocked to four earthen ponds of $1,616-1,848\;m^2$ in surface area as followings: polyculture LvP, L. vannamei ($43.4/m^2$)+puffer ($0.22/m^2$); control Lv, L. vannamei ($46.9/m^2$); polyculture FcP, F. chinensis ($30.3/m^2$)+puffer ($0.25/m^2$); control Fc, F. chinensis ($24.6/m^2$). Ponds of control Fc and polyculture FcP had mass mortalities by WSSV outbreak on the $51^{st}$ and $57^{th}$ days of culture respectively. The shrimps of polyculture LvP and control Lv were harvested on the $95^{th}\;day$. Shrimp survival rates of polyculture LvP and control Lv were 32.4% and 18.2% respectively and shrimp productivity of polyculture LvP was 69.2% higher than that of control Lv. Concentration of nutrients (TAN, $NO_2-N$, $NO_3-N$) was maintained within optimal ranges for shrimp growth although that of polyculture ponds showed at least two times higher than that of control ponds. The results suggest that polyculture of L. vannamei with river puffer is higher than monoculture in survival rate and productivity. In addition, F. chinensis should be carefully cultured because this species shows much higher susceptibility to WSSV than L. vannamei.

• Journal of fish pathology
• /
• v.23 no.3
• /
• pp.399-407
• /
• 2010

On the inner side of each operculum of the crucian carp, Carassius auratus (n=10), the leech, Limnotrachelobdella sinensis of 1-4 individuals were parasitic. The leeches had approximately 41.0 mm in total length and 11 mm in width. These body was composed with anterior sucker, neck, trunk and posterior sucker and average length was 2.3 mm, 7.2 mm, 23.3 mm and 8.7 mm respectively. To both sides of the trunk lateral vesicle of 11 pair existed. When observed by SEM, anterior sucker was hemisphere shape and the mouth where proboscis comes out existed with the its center. Proboscis was connected the esophagus directly. Under light microscopy, bloodsucking gill of C. auratus showed lamella fusion, hypertrophy the epithelial cell of the filament and lamella, increased mucocytes and congested capillaries. On the other hand, necrotic and hydropic degeneration epithelial cell of the lamella, and infiltration of the macrophages from some individuals were suggested the secondary infection with the bacteria or virus after bloodsucking activity of the leech.

• Korean Journal of Clinical Laboratory Science
• /
• v.46 no.1
• /
• pp.1-11
• /
• 2014

This research has been performed by our own investigation, also cooperated with Health and Sanification Division and each of district offices in Busan metropolitan city. After choosing, we collected water samples five times for microbiological examination. As a result of investigating in 160 water samples from urban areas, we could detect 88 cases of Vibrio spp. Furthermore, there were four cases exceeding the acceptable limit of aquarium water (100,00/mL) and another four cases exceeding the limit of Coliform group (1,000 below/100 mL). As a result of investigating that we performed for 271 cases of water samples from coastal areas from April to November, we could detect 130 cases of vibrio species and 10 cases of Coliform group. After performing 17 kinds of antibiotic susceptibility test for 41 cases of isolated Vibrio parahaemolyticus, 27 cases showed tolerance to Amplicllin (AM), all of 31 cases showed intermediate resistance only to Cefazolin (CF) but had sensitivity to the rest of them. As a result of performing antibiotic susceptibility test, serum test and PFGE gene analysis on each 10 pair of Vibrio parahaemolyticus detected concurrently from intake-pipe water and, aquarium water, we couldn't get data showing that they are clearly same species in three kinds of test. In addition, UV sterilization, Ozonization and so on. Based on our research, intake pipe didn't have a problem with microbiological contamination so we are sure that the germ came from supplied fish had caused that kind of contamination. For effective management, UV sterilization or Ozonization which can be handled consistently should be adopted in aquarium.

• Development and Reproduction
• /
• v.20 no.4
• /
• pp.297-304
• /
• 2016

Lectins belong to the pattern-recognition receptors (PRRs) class and play important roles in the recognition and elimination of pathogens via the innate immune system. Recently, it was reported that lily-type lectin-1 is involved when a pathogen attacks in the early immune response of fish. However, this study is limited to information that the lectin is involved in the innate immune response against viral infection. In the present study, the lily-type lectin-2 and -3 of Oplegnathus fasciatus (OfLTL-2 and 3) have been presented to be included B-lectin domain and two D-mannose binding sites in the amino acid sequence that an important feature for the fundamental structure. To investigate the functional properties of OfLTLs, the tissue distribution in the healthy rock bream and temporal expression during early developmental stage analysis are performed using quantitative real-time PCR. OfLTL-2 and 3 are predominantly expressed in the liver and skin, but rarely expressed in other organ. Also, the transcripts of OfLTLs are not expressed during the early developmental stage but its transcripts are increased after immune-related organs which are fully formed. In the challenge experiment with RBIV (rock bream iridovirus), the expression of OfLTLs was increased much more strongly in the late response than the early, unlike previously known. These results suggest that OfLTLs are specifically expressed in the immune-related tissues when those organs are fully formed and it can be inferred that the more intensively involved in the second half to the virus infection.

• Journal of Food Hygiene and Safety
• /
• v.24 no.1
• /
• pp.19-26
• /
• 2009

This study was undertaken to analyze the hygienic problems of group food services and to predict the outbreak patterns of future food-borne diseases. A delphi survey with 20 experts identified the main causes of food-borne outbreaks in group food services as improper hygienic management of raw food materials, washing of worker's hands, dividing the spaces and unsanitary retail storage. Vibrio parahaemolyticus, Escherichia coli (EPEC), non-typhoid Salmonella serotypes, Staphylococcus aureus, Escherichia coli (ETEC), norovirus, and the hepatitis A virus all have potential to cause outbreaks of food-borne disease. We analyzed the daily food use and the possibility of food-borne outbreaks in school food services for fruits, milk, fish, pork, eggs, and meat as raw food materials, and bibimbab, soybean sprouts muchim, spinach namul, cucumber sengchae, jabchae, and pork bulgogi as prepared food items. Frozen (${\leq}\;-20^{\circ}C$) and refrigerated ($0{\sim}10^{\circ}C$) processed foods are popular items in group food services. Their storage, heating, and chemical sanitization methods are potential sources of food disease outbreaks. Our results can be applied to a well-organized hygiene control system and can be used to develop menus for preventing food-borne outbreaks.

• Korean Journal of Ichthyology
• /
• v.30 no.4
• /
• pp.185-193
• /
• 2018

From 2017 to 2018, the disease has been monitored at four culturing eel farms in Incheon and Gyeonggi region in Korea. As a result, diseases with gill congestion frequently occurred. This disease occurred regardless of size of eel, but the frequency and cumulative mortality were high in eels within 3 months after stocking. The infected fish showed pathological histopathological features such as intense congestion and dilation in the central venous sinus (CVS) of gill filaments and hemorrhages in liver and kidney. Hexagonal viral particles measuring about 70 nm in diameter was observed in nuclei and cytoplasm of gill vascular endothelial cells. Molecular biologic diagnosis by both PCR and genetic analysis has been revealed that the causative agent of this disease is Japanese eel endothelial cells-infecting virus (JEECV), the cause of viral endothelial cell necrosis of eel (VECNE), which is mainly reported in Japan. This study is the first report on the characteristics of JEECV and VECNE infection in domestic eel farms.

• Journal of fish pathology
• /
• v.24 no.2
• /
• pp.65-73
• /
• 2011

In analysis of DNA viruses from the contaminated shellfish using PCR, preparation method of template DNA is an important factor to get enough copy number of viruses. In this study, we evaluated the efficiency of PCR template of Megalocytivirus (sT50mg-D) DNA obtained from 50 mg digestive gland homogenate of oyster using commercial method, and compared with that obtained from 5 g of the same tissues (T5g-D) after PEG precipitation procedures of virus. Both templates DNA suspended in the same volume of distilled water showed positive results by primary PCR with 35 cycles, and the presence of Megalocytivirus was confirmed in oysters collected from cultured farms in Korea. Moreover, PCR with sT50mg-D allowed us to discriminate the contaminated oyster individually, that can not be done in PCR with T5g-D prepared from the mixture of three different individual oyster to get 5 g digestive gland homogenate. In quantitative analysis with real time PCR, Megalocytivirus concentrations in 50 ${\mu}l$ templates prepared using 0.5~50 mg of one positive sample were appeared in the range 6.14E+00~1.2E+02/${\mu}l$. We were not able to get positive result using template DNA contained less than 6.14E+00 copies. Consequently, 2-step PCR performed with DNA extracts from oyster homogenate of small amount (sT50mg-D) i) was enough to detect the contaminated Megalocytivirus in shellfish, ii) allowed us to do the analysis for individual shellfish rather than mixture of several shellfish and iii) showed the presence of Megalocytivirus in oyster from Korea.