Genomic and Transcriptomic Diversification of Flagellin Genes Provides Insight into Environmental Adaptation and Phylogeographic Characteristics in Aeromonas hydrophila.

Aeromonas hydrophila is an opportunistic motile pathogen with a broad host range, infecting both terrestrial and aquatic animals. Environmental and geographical conditions exert selective pressure on both geno- and phenotypes of pathogens. Flagellin, directly exposed to external environments and containing important immunogenic epitopes, may display significant variability in response to external conditions.

Characterization and Pathogenicity of Isolated from Rainbow Trout () in Korea.

is the causative agent of bacterial cold-water disease in salmonids and rainbow trout fry syndrome. This pathogen has attained a global presence and can spread both horizontally and vertically. However, it was not documented in Korea before September 2018.

Comparative resistome analysis of Aeromonas species in aquaculture reveals antibiotic resistance patterns and phylogeographic distribution.

The overuse of antibiotics in aquaculture drives the emergence of multi-drug-resistant bacteria, and antibiotic-resistant genes (ARGs) can be disseminated to other bacteria through vertical- and horizontal gene transfer (VGT and HGT) under selective pressure. Profiling the antibiotic resistome and understanding the global distribution of ARGs constitutes the first step in developing a control strategy. Hence, this study utilized extensive genomic data from hundreds of Aeromonas strains in aquaculture to profile resistome patterns and explores their association with isolation year, country, and species characteristics.

Assessments of epidemic spread in aquaculture: comparing different scenarios of infectious bacteria incursion through spatiotemporal hybrid modeling.

The sustainable development of the aquaculture sector is at risk due to the significant challenges posed by many emerging infectious diseases. While disease prevention and control measures are becoming increasingly critical, there is a dearth of studies on the epidemiological aspects of disease transmission in aquatic ecosystems. This study aims to forecast the spread of a bacterial disease between fish farms in two regions, Romsdalsfjord in Norway and Gujwa in South Korea by applying a DTU-DADS-Aqua spatiotemporal hybrid simulation model.

Mechanisms underlying probiotic effects on neurotransmission and stress resilience in fish via transcriptomic profiling.

In recent years, studies have highlighted the significant impact of probiotic treatment on the central nervous system (brain) and stress regulation through the microbiota-gut-brain axis, yet there have been limited knowledge on this axis in fish. Therefore, this study aimed to enhance the current understanding of the mechanisms underlying probiotic effects on neurotransmission and stress alleviation in fish through transcriptomic profiling. In this study, olive flounders (Paralichthys olivaceus) were subjected to two trial setups: a 1-month lab-scale trial and a 6-month field-scale trial, with and without the probiotic strain Lactococcus lactis WFLU12.

Long-term persistence of piscine orthoreovirus-1 (PRV-1) infection during the pre-smolt stages of Atlantic salmon in freshwater.

Piscine orthoreovirus (PRV) causes heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon. During salmon production cycles, HSMI has predominantly been observed after seawater transfer. More recently, better surveillance and longitudinal studies have detected occurrences of PRV-1 in freshwater broodstock farms and hatcheries.

Molecular mechanisms underlying the vulnerability of Pacific abalone (Haliotis discus hannai) to Vibrio harveyi infection at higher water temperature.

Climate change is one of the most important threats to farmed abalone worldwide. Although abalone is more susceptible to vibriosis at higher water temperatures, the molecular mode of action underlying this has not been fully elucidated. Therefore, this study aimed to address the high susceptibility of Halitotis discus hannai to V.

Complete Genome Sequences of Streptococcus parauberis Serotype Ia, Ib/Ic, and II Isolates from Diseased Olive Flounder in South Korea.

We report the complete genome sequences of three isolates of Streptococcus parauberis, representing serotypes Ia, Ib/Ic, and II, which were isolated from diseased olive flounder (Paralichthys olivaceus) in South Korea.

Acute stress response on Atlantic salmon: a time-course study of the effects on plasma metabolites, mucus cortisol levels, and head kidney transcriptome profile.

Farmed Atlantic salmon (Salmo salar) welfare and performance can be strongly influenced by stress episodes caused by handling during farming practices. To better understand the changes occurring after an acute stress response, we exposed a group of Atlantic salmon parr to an acute stressor, which involved netting and transferring fish to several new holding tanks. We describe a time-course response to stress by sampling parr in groups before (T0) and 10, 20, 30, 45, 60, 120, 240, 300, and 330 min post-stress.

A genome-wide association study of the occurrence of genetic variations in Edwardsiella piscicida, Vibrio harveyi, and Streptococcus parauberis under stressed environments.

Bacterial mutation and genetic diversity in aquaculture have led to increasing phenotypic variances, which can weaken or invalidate strategies for controlling diseases. However, few studies have monitored the degree of mutation in fish bacterial pathogens caused by environmental pressure within a short period. In this study, transcriptomic sequences from Edwardsiella piscicida, Vibrio harveyi and Streptococcus parauberis under stressed environments were used for investigating the emergence of variants.

Identification and characterization of warm temperature acclimation proteins (Wap65s) in rainbow trout (Oncorhynchus mykiss).

Hemopexin is a vital glycoprotein for processing excessive iron in blood and functions as an iron scavenger in mammals. Teleosts however, unlike mammals, have two known hemopexin paralogs called warm temperature acclimation-related 65 kDa protein (Wap65-1 and Wap65-2, collectively termed Wap65s). Although Wap65s in rainbow trout have been considered notable biomarkers with significantly higher and/or lower expression under conditions of stress or disease, the individual roles, similarities and differences between the two paralogs are not well known.

Identification, classification and functional characterization of HSP70s in rainbow trout (Oncorhynchus mykiss) through multi-omics approaches.

Heat shock protein 70s (HSP70s) are known to play vital biological processes in rainbow trout. However, information on the numerous roles and classification of many different HSP70s is insufficient. The purpose of this study was to investigate the characteristics of all HSP70s in rainbow trout using multi-dimensional genomic and transcriptomic analyses for inspecting HSP70 homologs, phylogenetic characteristics, DNA motifs, and transcription factor binding sites (TFBSs).

Dual-Organ Transcriptomic Analysis of Rainbow Trout Infected With Through Co-Expression and Machine Learning.

is a major pathogen that causes a high mortality rate in trout farms. However, systemic responses to the pathogen and its interactions with multiple organs during the course of infection have not been well described. In this study, dual-organ transcriptomic responses in the liver and head kidney and hemato-serological indexes were profiled under infection and recovery to investigate systemic immuno-physiological characteristics.

Genotypic and Phenotypic Characterization of Highly Alkaline-Resistant V-Type ATPase from the Dairy Product Based on Comparative Genomics.

Although derived from dairy products has been used as a lactic acid bacterium industrially, several studies have reported potential pathogenicity and disease outbreaks. Because strains derived from diseased fish and dairy products are considered potentially virulent and beneficial, respectively, their genotypic and phenotypic characteristics have attracted considerable attention. A genome-wide comparison of 30 genome sequences (13, 3, and 14 strains from diseased aquatic animals, dairy products, and processed food, respectively) was carried out.

Transcriptome analysis unveils survival strategies of Streptococcus parauberis against fish serum.

Streptococcus parauberis is an important bacterial fish pathogen that causes streptococcosis in a variety of fish species including the olive flounder. Despite its importance in the aquaculture industry, little is known about the survival strategy of S. parauberis in the host.

The Complete Genome of Nocardia seriolae MH196537 and Intra-Species Level as Analyzed by Comparative Genomics Based on Random Forest Algorithm.

Nocardiosis is a major problem affecting fish that are farmed in seacages as well as freshwater fish; therefore, deciphering the bacteriological features of Nocardia seriolae is crucial. In particular, a number of studies over the past two years have reported the genome sequence of N. seriolae, and a comparative genomics approach is expected to yield valuable information on its epidemiological characteristics.

Differential proteome profile of gill and spleen in three pathogen-infected Paralichthys olivaceus.

Background: Olive flounder (Paralichthys olivaceus) is one of the major cultured fish species in Asia including Korea. However, the mass mortality of olive flounder caused by various pathogens leads to huge economic loss. The pathogens that lead to fish mortality include parasites, bacteria, and viruses that can cause various kinds of diseases.

Complete Genome Analysis of Flavobacterium psychrophilum Strain FPRT1, Isolated from Diseased Rainbow Trout (Oncorhynchus mykiss) in South Korea.

Here, we report the complete genome sequence of FPRT1, isolated from the spleen and kidney of diseased rainbow trout (). Whole-genome sequencing was performed using the PacBio RS II platform, which yielded a circular chromosome of 2,795,347 bp harboring 2,895 protein-coding genes.

Multi-Omics Analysis Provides Novel Insight into Immuno-Physiological Pathways and Development of Thermal Resistance in Rainbow Trout Exposed to Acute Thermal Stress.

In recent years, poikilothermic animals such as fish have increasingly been exposed to stressful high-temperature environments due to global warming. However, systemic changes in fish under thermal stress are not fully understood yet at both the transcriptome and proteome level. Therefore, the objective of this study was to investigate the immuno-physiological responses of fish under extreme thermal stress through integrated multi-omics analysis.

Overfeeding-Induced Obesity Could Cause Potential Immuno-Physiological Disorders in Rainbow Trout ().

Although over-nutrition from overfeeding-induced obesity is known to be highly associated with metabolic and immunological disorders in humans, little is known about overfeeding-induced obesity in fish farming. The purpose of this study was to investigate changes in immuno-physiological parameters, to better understand the potential risk of overfeeding-induced obesity in fish. Commercial feed was provided to fish in the overfed group until they refuse to eat, but fish in the control group was fed with the feed at 1% bodyweight per day.

Genome-wide comparison of Carnobacterium maltaromaticum derived from diseased fish harbouring important virulence-related genes.

Although Carnobacterium maltaromaticum has been used as a probiotic in fish, it was reported to cause disease for the first time in Korea. The objective of this study was to understand the differences between pathogenic and non-pathogenic strains. Pathogenicity was tested by challenging rainbow trout with C.

Determination of a peroxisome proliferator-activated receptor γ agonist, 1-(trans-methylimino-N-oxy)-6-(2-morpholinoethoxy-3-phenyl-1H-indene-2-carboxylic acid ethyl ester (KR-62980) in rat plasma by liquid chromatography-tandem mass spectrometry.

A novel peroxisome proliferator-activated receptor γ (PPARγ) agonist, KR-62980, was determined by liquid-liquid extraction with ethyl acetate and liquid chromatography-tandem mass spectrometry (LC/MS/MS) in rat plasma. In order to evaluate the pharmacokinetics of KR-62980, a reliable, selective and sensitive high-performance liquid chromatographic method with electrospray ionization tandem mass spectrometry was developed for the quantification of KR-62980 in rat plasma. KR-62980 and imipramine (IS) were separated on Hypersil GOLD C18 column with a mixture of acetonitrile-ammonium formate (10mM) (80:20, v/v) as mobile phase.

Determination of phloroglucinol in human plasma by high-performance liquid chromatography-mass spectrometry.

A sensitive and selective liquid chromatographic method coupled with mass spectrometry (LC-MS) was developed for the quantification of phloroglucinol in human plasma. Resorcinol was used as internal standard, with plasma samples extracted using ethyl acetate. A centrifuged upper layer was then evaporated and reconstituted with mobile phase.