Pharmacological evaluation on benzimidazole anthelmintics for eradication of the gill fluke Microcotyle sebastis infesting a black rockfish, Sebastes schlegelii.

This study comprehensively evaluated the in vitro and in vivo anthelmintic efficacy and pharmacokinetics of four benzimidazole compounds: febantel (FB), fenbendazole (FBZ), albendazole (ABZ), and mebendazole (MBZ) against the gill fluke Microcotyle sebastis in cultured black rockfish (Sebastes schlegelii). In vitro tests with isolated adult parasites demonstrated that ABZ exhibited the highest efficacy, followed by FBZ, while MBZ showed minimal activity and FB remained largely inactive at lower concentrations. At the highest concentration tested (200 mg/L), FB showed only weak, nonspecific activity.

Identification of Simultaneous Occurrence of Amphibian Chytrid Fungi and Ranavirus in South Korea.

Emerging infectious diseases such as chytridiomycosis and ranavirosis, caused by () and ranavirus (RV), respectively, are major contributors to global amphibian declines. Despite their significance, comprehensive data on the spatial epidemiology of these pathogens in South Korea remain limited. This study aimed to assess the nationwide co-occurrence and prevalence of and RV across four anuran species in five administrative regions.

Unlocking Immune Signatures: Surrogate Markers for Assessing VHSV Vaccine Efficacy in Olive Flounder ().

(VHSV) is a major pathogen in (olive flounder) aquaculture, necessitating effective vaccines and evaluation methods. This study assessed immune responses following intraperitoneal administration of an inactivated VHSV vaccine and identified surrogate markers of vaccine efficacy. Fish were sampled weekly over 8 weeks.

Evaluation of the diagnostic reliability of the gill-based Ray's fluid thioglycollate medium assay for Perkinsus olseni infections in Manila clams (Ruditapes philippinarum) across Korean tidal flats.

The alveolate protozoan parasite Perkinsus olseni infects a range of marine bivalves inhabiting tidal flats and shallow subtidal zones, causing considerable damage to shellfish industries. Infection by P. olseni is typically assessed using Ray's fluid thioglycollate medium (RFTM) assay, with gill tissue often employed as a diagnostic proxy for whole-body infection.

Comparative Pharmacological Assessment of Amoxicillin in Five Cultured Fish Species: Implications for Off-Label Use in Aquaculture.

: Amoxicillin (AMOX) is widely used in aquaculture for bacterial infections due to its efficacy and safety. Despite official approval for select species, off-label use is common. This study evaluated the antibacterial efficacy and residue depletion of AMOX in five aquaculture species: olive flounder (), rainbow trout (), Japanese eel (), black rockfish (), and Israeli carp ().

Serum and Tissue Kinetics of Oxolinic Acid in Black Rockfish (Sebastes schlegelii) Following a Single Oral Administration at Two Temperatures.

The objective of this study was to investigate the pharmacokinetic (PK) properties of oxolinic acid (OA) in black rockfish (Sebastes schlegelii) following a single oral administration of 30 mg/kg at 13°C and 22°C. Serum and tissue (muscle, liver and kidney) samples were collected at pre-determined time points and analysed using high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). The results demonstrated that temperature significantly influenced the PK parameters of OA.

Effects of Marigold Extract and Carophyll Red on Growth, Body Color Development, Antioxidant Properties, and Innate Immunity in the Ornamental Fish Golden Severum ().

The body color state is an important determinant of the value of golden severum ()-a popular ornamental fish. The use of dietary supplements to improve the color development and health of this species is unexplored. Herein, the effects of marigold extract (MG) and carophyll red (CR) are examined on the growth, body color development, antioxidant properties, and innate immunity in golden severum.

Development and validation of reverse-transcription cross-priming amplification-based lateral flow assay for the detection of infectious hematopoietic necrosis virus.

Infectious hematopoietic necrosis virus (IHNV) severely and lethally infects salmonid fish, including Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) worldwide. Rapid and accurate viral detection is crucial for preventing pathogen spread and minimizing damage. Although several IHNV detection assays have been developed, their analytical and diagnostic performances have not been evaluated and field usability assessments have not been completely validated.

The residue of salinomycin in the muscles of olive flounder (Paralichthys olivaceus) and black rockfish (Sebastes Schlegeli) after oral administration analyzed by LC-Tandem-MS.

Background: Salinomycin, an antibiotic, have potential as a veterinary drug for fish due to its anti-parasitic activity against several fish parasites. Thus the residual levels of salinomycin in muscles of two significant aquaculture species in Korea, olive flounder and black rockfish, were analyzed using HPLC-MS-MS.

Results: The proper method to analyze the residual salinomycin in fish muscles using LC-MS-MS was settled and the method was validated according to CODEX guidelines.

First report of Perkinsus olseni infections in blood cockles Tegillarca granosa on the south coast of Korea.

The protozoan parasite Perkinsus olseni has become a focus of attention since it has been responsible for mass mortalities and economic losses in a wide range of bivalve hosts globally. The P. olseni host range along the south coast of Korea may extend beyond what was previously understood, and blood cockles in the Family Arcidae are also suggested to be potential hosts of P.

Assessment of Salinomycin's Potential to Treat in Korean Rockfish ().

Aquaculture, a crucial sector of the global food industry, faces a myriad of issues due to parasitic invasions. One such parasite, , which afflicts Korean rockfish in South Korea, has a significant economic impact. The impending danger of resistance to traditional anthelmintics necessitates the exploration of new antiparasitic candidates.

Exploring the Efficacy and Safety of Levamisole Hydrochloride against in Korean Rockfish (): An In Vitro and In Vivo Approach.

Parasitic infections pose significant challenges in aquaculture, and the increasing resistance to conventional anthelmintics necessitates the exploration of alternative treatments. Levamisole hydrochloride (HCl) has demonstrated efficacy against monogenean infections in various fish species; however, research focused on infections in Korean rockfish () remains limited. Therefore, this study aimed to evaluate the efficacy of levamisole HCl against infections in Korean rockfish with the goal of optimizing anthelmintic usage in aquaculture.

Diagnostic validity of molecular diagnostic assays for white spot syndrome virus at different severity grades.

The high virulence of the white spot syndrome virus (WSSV) in acute infections and the lack of effective treatments underscore the necessity for a rapid, accurate, and efficient diagnostic process to control white spot disease. The analytical sensitivity of diagnostic assays (polymerase chain reactions; PCRs and rapid diagnostic kit) at different severity grades of WSSV infection were determined using the 95% limit of detection (LOD). The LOD of nested, real-time, and one-step PCRs and rapid diagnostic kit were 0.

Evaluation of the Horizontal Transmission of White Spot Syndrome Virus for Whiteleg Shrimp () Based on the Disease Severity Grade and Viral Shedding Rate.

White spot syndrome virus (WSSV) is the most problematic pathogen in crustaceans. In this study, we investigated the horizontal transmission model of WSSV based on the correlation between the disease severity grade and viral shedding rate and determined the minimum infective dose of WSSV via the waterborne route. Intramuscular injection challenges at different doses and water temperatures revealed that the thresholds of viral shedding and mortality were G1 (3.

Influence of Intramuscular Injection Sites on Pharmacokinetics of Amoxicillin in Olive Flounder () and Its Implication for Antibacterial Efficacy.

This study aimed to investigate the effects of different injection sites, including dorsal, cheek, and pectoral fin muscles, on the pharmacological properties of amoxicillin (AMOX) in olive flounder () after a single intramuscular (IM) injection of 40 mg/kg. The AMOX concentration was measured using high-performance liquid chromatography-tandem mass spectrometry, followed by a non-compartmental model analysis. The peak serum concentrations (C) achieved 3 h after dorsal, cheek, and pectoral fin IM injections were 202.

Red Sea Bream Iridovirus Kinetics, Tissue Tropism, and Interspecies Horizontal Transmission in Flathead Grey Mullets ().

Red sea bream iridovirus (RSIV) causes significant economic losses in the aquaculture industry. We analyzed the pathogenicity of RSIV in flathead grey mullets (), the correlation of histopathological lesions, and interspecies horizontal transmission, through immersion infection and cohabitation challenges. Flathead grey mullets, which were challenged by immersion infection, exhibited mortality at 14 and 24 days after RSIV exposure.

Impact of Red Sea Bream Iridovirus Infection on Rock Bream () and Other Fish Species: A Study of Horizontal Transmission.

Red sea bream iridovirus (RSIV) causes significant economic losses in aquaculture. Here, we analyzed the pathogenicity, viral shedding, and transmission dynamics of RSIV in rock bream () by employing immersion infection and cohabitation challenge models. Rock bream challenged by immersion exposure exhibited 100% mortality within 35 days post RSIV exposure, indicating that the viral shedding in seawater peaked after mortality.

First Report of Infection in Giant Freshwater Prawn ( de Man) Cultured in the Republic of Korea.

In the Republic of Korea, (EHP) was first isolated from Pacific whiteleg shrimp in April 2020; however, there are no existing reports of EHP infection in other shrimp or prawns. Here, we aimed to investigate EHP infection and its prevalence in giant freshwater prawn farms in the Republic of Korea. We tested prawns from 22 farms for EHP infection, and samples from eight farms showed positive EHP infection results in 2021.

Red Sea Bream Iridovirus (RSIV) Kinetics in Rock Bream () at Various Fish-Rearing Seawater Temperatures.

Red sea bream iridoviral disease (RSIVD) causes serious economic losses in the aquaculture industry. In this paper, we evaluated RSIV kinetics in rock bream under various rearing water temperatures and different RSIV inoculation concentrations. High viral copy numbers (approximately 10-10 RSIV genome copies/L/g) were observed during the period of active fish mortality after RSIV infection at all concentrations in the tanks (25 °C and 20 °C).

First Report of Infection in Pacific Whiteleg Shrimp () Cultured in Korea.

The consumption of cultured crustaceans has been steadily increasing, and Pacific whiteleg shrimp () are major cultivated invertebrates worldwide. However, shrimp productivity faces a variety of challenges, mainly related to outbreaks of lethal or growth retardation-related diseases. In particular, hepatopancreatic microsporidiosis caused by the microsporidian parasite (EHP) is an important disease associated with growth retardation in shrimp.

Pharmacokinetic-Pharmacodynamic Profile, Bioavailability, and Withdrawal Time of Tylosin Tartrate Following a Single Intramuscular Administration in Olive Flounder ().

The objective of this study was to demonstrate the pharmacokinetic-pharmacodynamic profile, bioavailability, and withdrawal time of tylosin tartrate (TT) administered to olive flounder via intramuscular (IM, 10 or 20 mg/kg, = 240) and intravascular (IV, 10 mg/kg, = 90) injections. Serum concentrations of tylosin were determined using a validated liquid chromatography-tandem mass spectrometry method. According to the non-compartmental analysis, the bioavailability of TT was 87%.

Naturally occurring substitution in one amino acid in VHSV phosphoprotein enhances viral virulence in flounder.

Viral hemorrhagic septicemia virus (VHSV) is a rhabdovirus that causes high mortality in cultured flounder. Naturally occurring VHSV strains vary greatly in virulence. Until now, little has been known about genetic alterations that affect the virulence of VHSV in flounder.

RNA-seq transcriptome analysis in flounder cells to compare innate immune responses to low- and high-virulence viral hemorrhagic septicemia virus.

Viral hemorrhagic septicemia virus (VHSV) is a rhabdovirus that causes high mortality in cultured flounder. Viral growth and virulence rely on the ability to inhibit the cellular innate immune response. In this study, we investigated differences in the modulation of innate immune responses of HINAE flounder cells infected with low- and high-virulence VHSV strains at a multiplicity of infection of 1 for 12 h and 24 h and performed RNA sequencing (RNA-seq)-based transcriptome analysis.

Molecular characterization of Urosporidium tapetis sp. nov., a haplosporidian hyperparasite infecting metacercariae of Parvatrema duboisi (Dollfus 1923), a trematode parasite of Manila clam Ruditapes philippinarum on the west coast of Korea.

Recently, a putative new hyperparasitic haplosporidian in the genus Urosporidium was identified from metacercariae of the trematode Parvatrema duboisi infecting Manila clam Ruditapes philippinarum on the west coast of Korea. In this study, we applied small subunit ribosomal DNA (SSU rDNA) sequences as a marker to substantiate the phylogenetic relationship of the unidentified Urosporidium within the Order Haplosporida. In our phylogenetic analysis, the 1890 bp of SSU rDNA sequences obtained were closely related to a haplosporidian parasite forming a sister clade to Urosporidium group, although the gene sequences were only 89.