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ABSTRACT: An effective vaccine strategy is indispensable against infectious bronchitis virus (IBV) and fowl typhoid (FT), both of which threaten the poultry industry. This study demonstrates a vector system, pJHL270, designed to express antigens in prokaryotic and eukaryotic cells. The vector system stimulates immune responses via synchronized antigen presentation to MHC class-I and -II molecules to produce balanced Th1/Th2 responses. The vaccine antigens were crafted by selecting the consensus sequence of the N-terminal domain of the spike protein (S1-NTD) and a conserved immunogenic region of the nucleocapsid protein (N321-406 aa) from IBV strains circulating in South Korea. The vaccine antigen was cloned and transformed into a live-attenuated Salmonella Gallinarum (SG) strain, JOL2854 (∆lon, ∆cpxR, ∆rfaL, ∆pagL, ∆asd). Western blot analysis confirmed concurrent antigen expression in Salmonella and eukaryotic cells. Oral immunization with the SG-based IBV vaccine construct JOL2918 induced IBV antigen and Salmonella-specific humoral and cell-mediated immune responses in chickens. PBMCs collected from immunized chickens revealed that MHC class-I and -II expression had increased 3.3-fold and 2.5-fold, respectively, confirming MHC activation via bilateral antigen expression and presentation. Immunization induced neutralizing antibodies (NAbs) and reduced the viral load by 2-fold and 2.5-fold in the trachea and lungs, respectively. The immunized chickens exhibited multifaceted humoral, mucosal, and cell-mediated responses via parallel MHC class-I and -II activation as proof of a balanced Th1/Th2 immune response. The level of NAbs, viral load, and gross and histological analyses provide clear evidence that the construct provides protection against IBV and FT.

Abstract Korean water deer (Hydropotes inermis argyropus; Heude, 1884) and Siberian roe deer (Capreolus pygargus; Pallas, 1771) are Korean wild deer classified in the tribe Capreolini. C. pygargus in Korea were previously considered a single species; however, it was recently suggested that roe deer living on Jeju Island (Jeju roe deer; Capreolus pygargus jejuensis) is a distinct subspecies from roe deer living on the Korean peninsula (mainland roe deer; Capreolus pygargus tianschanicus) based on several studies demonstrating genetic and morphological features. In this study, we suggests that the scapular morphology and osteometric data can be used for interspecies discrmination between Korean wild deer. To compare the morphological characteristics of scapula among the three groups of deer, we analyzed the features and nine osteomorphological measurements of 31 H. i. argyropus (14 males and 17 females), 18 C. p. jejuensis (4 males and 14 females), and 23 C. p. tianschanicus (16 females and 7 males). The estimated ages of the deer were over 32–35 months. Data were analyzed by one-way repeated measures analysis of variance with post hoc Duncan test and discriminant functional analysis (DFA). H. i. argyropus and C. p. tianschanicus had the smallest and largest scapulae, respectively. The scapulae of the three Korean wild deer had a similar triangular shape, which was obscured by the tuber of the scapular spine, pointed acromion, broad infraspinous fossa, narrow supraspinous fossa, and partial ossification of scapular cartilage in older deer. H. i. argyropus had certain distinctive features, including a caudally pointed acromion, a notch between the supraglenoid tubercle and glenoid cavity (NBSG), a glenoid notch, and no sexual dimorphism, except for the longest dorsal length (Ld) and the scapular index (SI). C. p. jejuensis had a larger scapular index (SI) (61.74 ± 0.74%), compared with the SIs of H. i. argyropus and C. p. tianschanicus. The unique features of the scapula in C. p. jejuensis include its S-shaped cranial border. The C. p. jejuensis had a cranially pointed acromion, less frequent presence of glenoid notch and NBSG, short length of supraglenoid tubercle, and no sexual dimorphism. The C. p. tianschanicus had elevated cranial margin of the glenoid cavity, and frequent presence of glenoid notch and NBSG, similar to the H. i. argyropus. Similar to C. p. jejuensis, C. p. tianschanicus had a cranially pointed acromion. However, sexual dimorphism was observed in C. p. tianschanicus. DFA using osteometric data showed 97.22% of specimens were classified correctly into their species, meaning the osteometric parameters can be used for interspecies discrimination of Korean wild deer. Our findings indicate that the scapular morphologies of the three Korean wild deer have certain similarities and differences, suggesting that C. p. jejuensis are distinct from C. p. tianschanicus.

Organizations managing high-performance computing systems face a multitude of challenges, including overarching concerns such as overall energy consumption, microprocessor clock frequency limitations, and the escalating costs associated with chip production. Evidently, processor speeds have plateaued over the last decade, persisting within the range of 2 GHz to 5 GHz. Scholars assert that brain-inspired computing holds substantial promise for mitigating these challenges. The spiking neural network (SNN) particularly stands out for its commendable power efficiency when juxtaposed with conventional design paradigms. Nevertheless, our scrutiny has brought to light several pivotal challenges impeding the seamless implementation of large-scale neural networks (NNs) on silicon. These challenges encompass the absence of automated tools, the need for multifaceted domain expertise, and the inadequacy of existing algorithms to efficiently partition and place extensive SNN computations onto hardware infrastructure. In this paper, we posit the development of an automated tool flow capable of transmuting any NN into an SNN. This undertaking involves the creation of a novel graph-partitioning algorithm designed to strategically place SNNs on a network-on-chip (NoC), thereby paving the way for future energy-efficient and high-performance computing paradigms. The presented methodology showcases its effectiveness by successfully transforming ANN architectures into SNNs with a marginal average error penalty of merely 2.65%. The proposed graph-partitioning algorithm enables a 14.22% decrease in inter-synaptic communication and an 87.58% reduction in intra-synaptic communication, on average, underscoring the effectiveness of the proposed algorithm in optimizing NN communication pathways. Compared to a baseline graph-partitioning algorithm, the proposed approach exhibits an average decrease of 79.74% in latency and a 14.67% reduction in energy consumption. Using existing NoC tools, the energy-latency product of SNN architectures is, on average, 82.71% lower than that of the baseline architectures.

Amid the escalating challenges of antibiotic resistance, bacterial infections have emerged as a global threat. Bacteriophages (phages), viral entities capable of selectively infecting bacteria, are gaining momentum as promising alternatives to traditional antibiotics. Their distinctive attributes, including host specificity, inherent self-amplification, and potential synergy with antibiotics, render them compelling candidates. Phage engineering, a burgeoning discipline, involves the strategic modification of bacteriophages to enhance their therapeutic potential and broaden their applications. The integration of CRISPR-Cas systems facilitates precise genetic modifications, enabling phages to serve as carriers of functional genes/proteins, thereby enhancing diagnostics, drug delivery, and therapy. Phage engineering holds promise in transforming precision medicine, addressing antibiotic resistance, and advancing diverse applications. Emphasizing the profound therapeutic potential of phages, this review underscores their pivotal role in combatting bacterial diseases and highlights their significance in the post-antibiotic era.

Abstract Background Antibiotic-resistant bacteria have emerged as a serious problem; bacteriophages have, therefore, been proposed as a therapeutic alternative to antibiotics. Several authorities, such as pharmacopeia, FDA, have confirmed their safety, and some bacteriophages are commercially available worldwide. The demand for bacteriophages is expected to increase exponentially in the future; hence, there is an urgent need to mass-produce bacteriophages economically. Unlike the replication of non-lytic bacteriophages, lytic bacteriophages are replicated by lysing host bacteria, which leads to the termination of phage production; hence, strategies that can prolong the lysis of host bacteria in bacteria–bacteriophage co-cultures, are required. Results In the current study, we manipulated the inoculum concentrations of Staphylococcus aureus and phage pSa-3 (multiplicity of infection, MOI), and their energy sources to delay the bactericidal effect while optimizing phage production. We examined an increasing range of bacterial inoculum concentration (2 × 108 to 2 × 109 CFU/mL) to decrease the lag phase, in combination with a decreasing range of phage inoculum (from MOI 0.01 to 0.00000001) to delay the lysis of the host. Bacterial concentration of 2 × 108 CFU/mL and phage MOI of 0.0001 showed the maximum final phage production rate (1.68 × 1010 plaque forming unit (PFU)/mL). With this combination of phage–bacteria inoculum, we selected glycerol, glycine, and calcium as carbon, nitrogen, and divalent ion sources, respectively, for phage production. After optimization using response surface methodology, the final concentration of the lytic Staphylococcus phage was 8.63 × 1010 ± 9.71 × 109 PFU/mL (5.13-fold increase). Conclusions Therefore, Staphylococcus phage pSa-3 production can be maximized by increasing the bacterial inoculum and reducing the seeding phage MOI, and this combinatorial strategy could decrease the phage production time. Further, we suggest that response surface methodology has the potential for optimizing the mass production of lytic bacteriophages.

Abstract Due to their important phylogenetic position among extant vertebrates, sharks are an invaluable group in evolutionary developmental biology studies. A thorough understanding of shark anatomy is essential to facilitate these studies and documentation of this iconic taxon. With the increasing availability of cross-sectional imaging techniques, the complicated anatomy of both cartilaginous and soft tissues can be analyzed non-invasively, quickly, and accurately. The aim of this study is to provide a detailed anatomical description of the normal banded houndshark (Triakis scyllium) using computed tomography (CT) and magnetic resonance imaging (MRI) along with cryosection images. Three banded houndsharks were scanned using a 64-detector row spiral CT scanner and a 3 T MRI scanner. All images were digitally stored and assessed using open-source Digital Imaging and Communications in Medicine viewer software in the transverse, sagittal, and dorsal dimensions. The banded houndshark cadavers were then cryosectioned at approximately 1-cm intervals. Corresponding transverse cryosection images were chosen to identify the best anatomical correlations for transverse CT and MRI images. The resulting images provided excellent detail of the major anatomical structures of the banded houndshark. The illustrations in the present study could be considered as a useful reference for interpretation of normal and pathological imaging studies of sharks.

Cetaceans have long been considered biologically adapted to suffer no adverse effects from diving-related tissue gas tension. However, increasing reports of gas embolism in cetaceans inhabiting European, Mediterranean and American waters have challenged the conventional understanding of marine mammal diving physiology. In human hyperbaric medicine, virtopsy techniques such as post-mortem computed tomography (PMCT) facilitate the visualization of gas embolism and could be performed adjunct to conventional autopsy. This research presents the first case of gas embolism identified in an East Asian finless porpoise inhabiting Asian waters. Massive gas embolic lesions were found in the liver, which had been compressing both the lungs and abdominal organs, and signs of pneumonia and parasitic infection were observed in both lungs. It is hypothesized that this porpoise might have been unable to expel in vivo gas bubbles from its circulation due to pulmonary dysfunction. Consequently, gas bubbles agglomerated in the liver, resulting in the development of gas embolic lesions. The findings of the present study provide insights into the occurrence of gas embolism in the East Asian finless porpoise, highlighting the potential of PMCT as a promising tool for the diagnosis of gas embolism in stranded cetaceans.

Copper shark (Carcharhinus brachyurus Günther, 1870) is one of the most widely distributed but least known species in the family Carcharhinidae. Herein, we report the first complete mitogenome of C. brachyurus. The overall structure of the 16,704 bp C. brachyurus mitogenome was similar to that of other Carcharhinus species and showed the highest average nucleotide identity (97.1%) with the spinner shark (Carcharhinus brevipinna). Multigene phylogeny using 13 protein-coding genes (PCGs) in the mitogenome resolved C. brachyurus clustered with other species within the genus; the overall tree topology was congruent with recent phylogenetic studies of this species. These results provide important information for conservation genetics and further evolutionary studies of sharks.

Dietary protein is required to support recovery and adaptation following exercise training. While prior research demonstrates that many athletes meet total daily protein needs, intake seems to be predominantly skewed toward the evening meal. An even distribution of protein doses of ≥0.24 g/kg BW consumed throughout the course of a day is theorized to confer greater skeletal muscle anabolism outcomes compared to a skewed pattern of intake. Protein quality is also an important dietary consideration for athletes, with the amino acid leucine seemingly serving as the primary driver of the postprandial anabolic response. The present study investigates protein consumption characteristics among a cohort of NCAA D1 soccer players and evaluates differences between male and female athletes. Athletes were instructed to complete 3-day food diaries, which were subsequently analyzed and compared to UEFA expert group-issued nutrition guidelines for soccer players. Breakfast, lunch, and dinner accounted for 81.4% of the total daily dietary protein intake. Most athletes (77.8%) ingested optimum amounts of protein at dinner but not at breakfast (11.1%) or lunch (47.2%). In addition, statistically significant sex-based differences in daily dietary protein intake, meal-specific protein amounts, and protein quality measures were detected. Findings indicate suboptimal dietary protein intake practices among the collegiate soccer athletes.

Recently, there has been an increasing number of blight disease reports associated with Erwinia amylovora and Erwinia pyrifoliae in South Korea. Current management protocols that have been conducted with antibiotics have faced resistance problems and the outbreak has not decreased. Because of this concern, the present study aimed to provide an alternative method to control the invasive fire blight outbreak in the nation using bacteriophages (phages) in combination with an antibiotic agent (kasugamycin). Among 54 phage isolates, we selected five phages, pEa_SNUABM_27, 31, 32, 47, and 48, based on their bacteriolytic efficacy. Although only phage pEa_SNUABM_27 showed host specificity for E. amylovora, all five phages presented complementary lytic potential that improved the host infectivity coverage of each phage All the phages in the cocktail solution could lyse phage-resistant strains. These strains had a decreased tolerance to the antibiotic kasugamycin, and a synergistic effect of phages and antibiotics was demonstrated both in vitro and on immature wound-infected apples. It is noteworthy that the antibacterial effect of the phage cocktail or phage cocktail-sub-minimal inhibitory concentration (MIC) of kasugamycin was significantly higher than the kasugamycin at the MIC. The selected phages were experimentally stable under environmental factors such as thermal or pH stress. Genomic analysis revealed these are novel Erwinia-infecting phages, and did not encode antibiotic-, virulence-, or lysogenic phage-related genes. In conclusion, we suggest the potential of the phage cocktail and kasugamycin combination as an effective strategy that would minimize the use of antibiotics, which are being excessively used in order to control fire blight pathogens.

Otitis externa, a common disease in dogs, has different etiologies. Enterococcus is a Gram-positive bacterium that frequently causes opportunistic ear infections. Here, we determined the distribution of Enterococcus in canine otitis externa via time-of-flight mass spectrometry and biochemical tests and evaluated their resistance patterns to 10 commonly used antibiotics. Among the 197 Enterococcus isolates, E. faecalis (48.7%; 96/197) was the most common, followed by E. faecium (21.3%; 42/197), E. casseliflavus (11.7%; 23/197), E. hirae (10.7%; 21/197), E. avium (3.6%; 7/197), E. gallinarum (2.5%; 5/197), E. canintestini (1.0%; 2/197), and E. durans (0.5%; 1/197). All isolates were tested for antibiotic resistance using the Kirby–Bauer disc diffusion method. Enterococcus faecalis strains were highly resistant to erythromycin (45.8%) and rifampin (34.3%) but were generally susceptible to penicillin class antibiotics. In contrast, E. faecium isolates were highly resistant to penicillin class antibiotics (ampicillin, 61.9%; penicillin, 71.4%). Most importantly, E. faecium demonstrated high resistance to most of the antibiotics used in this study. Multidrug resistance was found in 28.4% of the isolates (56/197). This study shows prevalence and antibiotics resistance profiles of Enterococcus species in canine chronic otitis externa. The results can contribute to establish therapeutic strategies of Enterococcus infections and be used as a comparable index of antibiotic resistance of Enterococcus in the future.

Otitis externa is among the most prevalent diseases in dogs. If the underlying cause is not addressed, bacterial reinfection becomes frequent, necessitating antibiotic administration for an extended period of time. Prolonged treatment promotes the emergence of antibiotic-resistant bacteria and increases the risk of their transmission from animals to humans. This study aimed to analyze the antibiotic resistance pattern of the emerging pathogen Proteus mirabilis to identify bacterial virulence and antibiotic selection. Samples were collected from randomly encountered dogs with chronic otitis externa. Thirty-two strains of P. mirabilis were isolated and identified, using MALDI-TOF. The Kirby-Bauer disk diffusion method was used to assess the antibiotic susceptibility of P. mirabilis to 11 antibiotics. The isolates (n = 32) were most resistant to cefazolin (75%), trimethoprim–sulfamethoxazole (72%), chloramphenicol (72%), amoxicillin–clavulanate (63%), ampicillin (59%), cefepime (56%), ciprofloxacin (53%), aztreonam (50%), ceftazidime avibactam (50%), gentamicin (22%), and amikacin (16%). Moreover, 75% of isolates were found to be multidrug-resistant bacteria. P. mirabilis was found to have a high resistance-pattern ratio. Although the exact cause is unknown, continuous antibiotic use is thought to be a major factor. We concluded that antibiotic use must be prudent and selective to prevent antibiotic resistance.

Curcumin exhibited numerous key activities including antioxidant, anti-inflammatory, and immunostimulatory effects in fish. This study evaluated the protective effects of curcumin (CUR) against lead (Pb)-induced toxicities in fish. Healthy Cyprinus carpio L. individuals were segregated into control, Pb only, Pb+CUR, and CUR only groups. Pb groups were exposed to 1 mg L −1 of Pb, and CUR groups were fed a basal diet supplemented with 15 g kg−1 of CUR. After eight weeks, growth performance, Pb accumulation in tissues, various haemato-biochemical parameters, immune responses, and cytokine gene expression were measured. Dietary CUR effectively decreased Pb accumulation in tissues and increased the survival of Pb-exposed fish. Co-treatment with Pb and CUR reversed alterations in haemato-biochemical parameters, ameliorated Pb-induced oxidative stress, enhanced immune responses, and restored intestinal enzymatic activities. Dietary CUR reversed changes in intestinal microbiota in Pb-exposed fish. Pb-induced upregulation of NF-κBp65 and HSP70 was inhibited by dietary CUR. CUR supplementation upregulated the mRNA levels of SOD, Nrf2, IL-10, and CYP450 1A and attenuated Pb-induced degradation of I κB-α mRNA levels. Overall, CUR antagonizes Pb-induced negative impacts in fish. Thus, dietary CUR had several beneficial effects on immune responses, decreased Pb accumulation in tissues, and reversed Pb-induced oxidative stress in fish. Therefore, CUR plays a protective role in Pb-induced immune toxicity in fish, and, as such, may be suitable as an aqua feed additive for use in carp aquaculture.

A gangliocytic paraganglioma is a benign tumor of the digestive system with a very low incidence. The tumor is histopathologically characterized by a triphasic pattern consisting of epithelioid, ganglion, and spindle-shaped Schwann cells. In most cases, it occurs in the second portion of the duodenum near the ampulla of Vater. We report a case of a gangliocytic paraganglioma occurring at the minor duodenal papilla (a rare location) with a concurrent adenoma of the ampulla of Vater. Both lesions were treated simultaneously using endoscopic resection. Additionally, we have presented a literature review.

As a primary bacterial pathogen in companion animals, Staphylococcus pseudintermedius has zoonotic potential. This pathogen exhibits multidrug resistance, including resistance to methicillin, and biofilm-forming ability, making it hard to eradicate with antimicrobial agents. One potential alternative is bacteriophage therapy. In this study, we first characterized the antimicrobial resistance profile of S. pseudintermedius from canine samples and isolated two novel bacteriophages, pSp-J and pSp-S, from canine pet parks in South Korea to potentially control S. pseudintermedius. The biological characteristics of phages were assessed, and the phages could infect most of the methicillin-resistant S. pseudintermedius strains. We found that these phages were stable under the typical environment of the body (~37°C, pH 7). We also assessed bacterial lysis kinetics using the two phages and their cocktail, and found that the phages could prevent biofilm formation at low doses and could degrade biofilm at high doses. Taken together, this study demonstrates that bacteriophages pSp-J and pSp-S isolated in this study can be used to potentially treat methicillin-resistant S. pseudintermedius.

Shark populations are constantly decreasing owing to environmental destruction and overfishing; thus, sharks are now at a risk of extinction, with 27.9% of shark species classified as endangered on the International Union for Conservation of Nature’s Red List. Sharks are apex predators and a keystone species in balancing the marine food chain; their extinction will create an imbalance of the entire marine ecosystem. Assisted reproductive technology is the last resort for protecting animals facing severe extinction. Here, as a proactive effort toward building a hormone-induced artificial insemination protocol for endangered wild sharks, we identified the possibility of germ cell maturation by administration of Ovaprim®, a commercially produced synthetic salmon gonadotropin-releasing hormone, and calculated its optimum dosage and injection timing. The experiment was conducted on two shark species—Triakis scyllium and Triaenodon obesus. We found that intramuscular injections of 0.2 mL/kg of Ovaprim® for male T. scyllium and T. obesus, 0.2 mL/kg + 0.5 mL/kg at a 24 h interval for female T. scyllium, and 0.2 mL/kg + 0.2 mL/kg or 0.2 mL/kg + 0.3 mL/kg at a 24 h interval for female T. obesus were optimal dose protocols. These doses effectively induced the maturation and ovulation of oocytes and the release of semen. Our results confirm that Ovaprim® is a suitable tool for shark hormone-induced artificial insemination and indicate that this method may enable the conservation of the endangered shark species.

Yellow-pigmented, circular bacteria (strain SNU WT7) were isolated from the liver of moribund eastern catfish (Silurus asotus). Our study focused on the taxonomic description of SNU WT7 using phylogenetic, phenotypic, and chemotaxonomic analyses. The 16S rRNA gene sequence of the SNU WT7 strain was highly similar to that of Chryseobacterium haifense H38T (97.29% similarity), followed by Chryseobacterium hominis P2K6T (97.22% similarity), while other species exhibited similarity values of less than 97.0%. The genome of strain SNU WT7 displayed average nucleotide identity and genome-to-genome distance values of 72.35% and 22.0%, respectively, which clearly indicated that the novel species was distant from the other Chryseobacterium species, with its closest relative being C. haifense H38T. Furthermore, the phenotypic characteristics, including acid production from glucose, D-fructose, lactose, and maltose, of strain SNU WT 7 differed from those of C. haifense H38T. The major polar lipid of the strain was phosphatidylethanolamine, and several unidentified aminolipids and lipids were also present. Similar to other Chryseobacterium species, the quinone system was composed mainly of MK-6. The genome of SNU WT7 is 2,690,367 bp with a G + C content of 43.6%. Taken together, our data indicate that the isolate SNU WT7 represents a novel species of the genus Chryseobacterium. Thus, we present the name Chryseobacterium siluri sp. nov. for the novel type strain SNU WT7T (KCTC 72626, JCM 33707).

Edwardsiella species are one of the top causative pathogens of mortality in various fisheries worldwide. Their role in zoonotic infections and increase in antibiotic-resistance has raised concerns and interests in many research fields. Similar to the studies investigating human clinical cases, there has been an increase in research examining the potential pathogenic role of the bacterium in aquaculture. Within the Edwardsiella family, Edwardsiella anguillarum was lastest group to be differentiated from the Edwardsiella tarda group, and many studies focusing on the virulence of this species have since ensued. In Korea, only E. tarda infections have been reported in aquaculture industries, and there have been no reports on economic losses incurred owing to E. anguillarum infection. There has been a recent report investigating the pathogenicity and pathological changes caused by E. anguillarum infection in a tilapia farm located in the Costa Rica. To the best of our knowledge, as ours is the first report of E. anguillarum infection in a Nile tilapia (Oreochromis niloticus) farm located in an Asian country, the pathogenicity of the bacterial strain was histopathologically compared to that of the past studies. As tilapia is one of the most globally consumed fish species, particularly throughout Asia, Europe, and America, an epidemiological study regarding the disease distribution is necessary for the control and prevention of the disease. Here, we report the first mass mortality case caused by E. anguillarum infection in a Nile tilapia farm located in Korea; the bacterial strain responsible was isolated, characterized, and pathologically analyzed.

This study aimed to re-evaluate the pathogenic characteristics of Chryseobacterium balustinum, generally known as a food spoilage bacterium. We observed mass mortality in a rainbow trout farm in Jeonbuk province, Republic of Korea. Fewer studies have reported on rainbow trout mortality or infections in Korea than in other countries; among these, few studies have reported cases of Chryseobacterium infections. Sequencing analysis revealed that this bacterium is closely related (99.24%) to Chryseobacterium balustinum. Bacterial identification assays, including the API test, sequencing, and phylogenetic analysis, found the 24 isolates to be C. balustinum. The strain showed multiple resistance to 18 of 25 antibiotics tested. Primary clinical symptoms of its infection are damage to the fins, necrosis, and cytoplasmic vacuolation in hepatocytes. The pathogenicity of the strain was determined following Koch’s postulates and the challenge test. The present results suggest that C. balustinum WLT can be considered a multidrug-resistant zoonotic pathogen responsible for mortality and economic losses.

A two-year-old ball python with a submandibular mass was evaluated. Fine needle aspiration resulted in debris containing purulent materials and bacterial cells on cytology. Radiography demonstrated multi-focal radiopaque lesions in the mass, which were suspected to be mineralization; there was an absence of mandibular invasion or lung involvement. Gross examination of the surgically excised mass revealed a multi-nodular, well-circumscribed lesion with purulent material. The postoperative recovery was uneventful. The histopathological examination followed by immunohistochemistry analysis gave a diagnosis of leiomyosarcoma. As tumors containing purulent materials can be confused with an abscess, diagnostic confirmation with various diagnostical tools should be considered.

The bacterial genus Pseudomonas is a common causative agent of infections in veterinary medicine. In this study, we focused on Pseudomonas aeruginosa canine otitis externa isolates. Due to prolonged antibiotic treatment of otitis externa, antibiotic resistance is common and has become a major complication. Many alternatives to antibiotics have been studied, with bacteriophages emerging as the most promising alternatives. Here, we isolated and characterized a novel phage, pPa_SNUABM_DT01, by investigating its morphology, growth, lysis kinetics, and genomic characteristics. Phages have a vigorous capacity to eliminate bacterial cells through bacterial lysis. This capacity is dependent on the multiplicity of infection (MOI), but even at low MOIs, the phage successfully inhibited bacterial regrowth. The phage genome was 265,520 bp in size and comprised 312 putative open reading frames (ORFs). Comparative genome analysis demonstrated that the phage is a novel species in Myoviridae. The nucleotide similarity was moderately high compared with the Pseudomonas virus, Noxifer. However, a phylogenetic analysis and a dot plot indicated that pPa_SNUABM_DT01 is not closely related to the Phikzvirus or Noxifervirus genus but, instead, belongs to a novel one. The genome comparisons also indicate that the phage, pPa_SNUABM_DT01, could be a novel genus.

Species belonging to the genus Erwinia are predominantly plant pathogens. A number of bacteriophages capable of infecting Erwinia have been used for the control of plant diseases such as fire blight. Public repositories provide the complete genome information for such phages, which includes genomes ranging from 30 kb to 350 kb in size. However, limited information is available regarding bacteriophages belonging to the family Siphoviridae. A novel lytic siphophage, pEp_SNUABM_08, which specifically infects Erwinia pyrifoliae, was isolated from the soil of an affected apple orchard in South Korea. A comprehensive genome analysis was performed using the Erwinia-infecting siphophage. The whole genome of pEp_SNUABM_08 comprised 62,784 bp (GC content, 57.24%) with 79 open reading frames. The genomic characteristics confirmed that pEp_SNUABM_08 is a singleton lytic bacteriophage belonging to the family Siphoviridae, and no closely related phages have been reported thus far. Our study not only characterized a unique phage, but also provides insight into the genetic diversity of Erwinia bacteriophages.

Shark meat is consumed as a food source worldwide, especially in Asian countries. However, since sharks are apex predators in the ocean food chain, they are prone to bioaccumulation of heavy metals. More than 100 million sharks are caught annually for human consumption, and the safety of shark meat cannot be overemphasized. Here, we examined heavy metal concentration in the muscle tissue of 6 shark species including 3 migratory species (Carcharhinus brachyurus, Carcharhinus obscurus, and Isurus oxyrinchus) and 3 local species (Triakis scyllium, Mustelus manazo, and Cephaloscyllium umbratile) from fish markets in Jeju Island, Republic of Korea. The concentrations of 11 heavy metals (Cr, Fe, Cu, Zn, As, Se, Cd, Sn, Sb, Pb, and Hg) and MeHg were analyzed. The result showed that the average concentrations of all metals, except for that of As, were below the regulatory maximum limits of many organizations, including the Codex standard. Hg and MeHg were significantly correlated with body length, body weight, and age, and the concentration of Hg was expected to exceed the limit in C. brachyurus with a body length or weight of over 130 cm or 25 kg, respectively. Our results indicate that shark meat can expose consumers to a high level of As and that copper sharks bigger than the predicted size should be avoided for excessive Hg. Considering these findings, a detailed guideline on consumption of meat of different shark species should be suggested based on further investigation.

This study presents a novel Janthinobacterium strain, SNU WT3, isolated from the kidney of rainbow trout. A phylogenetic study using 16S rRNA sequences indicated that the strain is closely related to Janthinobacterium svalbardensis JA-1T. However, biochemical analysis found differences in D-xylose adonitol, N-acetylglucosamine, arbutin, and cellobiose. As for genome-to-genome distance and average nucleotide identity values calculated between strain SNU WT3 and other related strains such as J. lividum EIF1, J. svalbardensis PAMC 27463, and J. agaricidamnosum BHSEK were all below the cutoff value between species. DNA-DNA hybridization between strain SNU WT3 and other close relatives indicated the results of J. lividum DSM 1522T (47.11%) and J. svalbardensis JA-1T (38.88%) individually. The major fatty acid compositions of strain SNU WT3 were cylco-C17:0 (41.45%), C16:0 (33.86%) and C12:0 (5.87%). The major polar lipids were phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol, and diphosphatidylglycerol. The quinone system was composed mainly of ubiquinone Q-8. The genome of strain SNU WT3 consists of 6,314,370 bp with a G + C content of 62.35%. Here, we describe a novel species of the genus Janthinobacterium, and the name Janthinobacterium tructae has been proposed with SNU WT3T (=KCTC 72518 = JCM 33613) as the type strain.

A novel Citrobacter species was isolated from the kidney of diseased rainbow trout (Oncorhynchus mykiss) reared on a trout farm. Biochemical characterization and phylogenetic analysis were performed for bacterial identification. Sequencing of the 16S rRNA gene and five housekeeping genes indicated that the strain belongs to the Citrobacter genus. However, multilocus sequence analysis, a comparison of average nucleotide identity, and genome-to-genome distance values revealed that strain SNU WT2 is distinct and forms a separate clade from other Citrobacter species. Additionally, the phenotype characteristics of the strain differed from those of other Citrobacter species. Quinone analysis indicated that the predominant isoprenoid quinone is Q-10. Furthermore, strain virulence was determined by a rainbow trout challenge trial, and the strain showed resistance to diverse antibiotics including β-lactams, quinolone, and aminoglycosides. The complete genome of strain SNU WT2 is 4,840,504 bp with a DNA G + C content of 51.94% and 106,068-bp plasmid. Genome analysis revealed that the strain carries virulence factors on its chromosome and antibiotic resistance genes on its plasmid. This strain represents a novel species in the genus Citrobacter for which the name C. tructae has been proposed, with SNU WT2 (=KCTC 72517 = JCM 33612) as the type strain.

The increasing emergence of antimicrobial resistance has become a global issue. Therefore, many researchers have attempted to develop alternative antibiotics. One promising alternative is bacteriophage. In this study, we focused on a jumbo-phage infecting Salmonella isolated from exotic pet markets. Using a Salmonella strain isolated from reptiles as a host, we isolated and characterized the novel jumbo-bacteriophage pSal-SNUABM-04. This phage was investigated in terms of its morphology, host infectivity, growth and lysis kinetics, and genome. The phage was classified as Myoviridae based on its morphological traits and showed a comparatively wide host range. The lysis efficacy test showed that the phage can inhibit bacterial growth in the planktonic state. Genetic analysis revealed that the phage possesses a 239,626-base pair genome with 280 putative open reading frames, 76 of which have a predicted function and 195 of which have none. By genome comparison with other jumbo phages, the phage was designated as a novel member of Machinavirus composed of Erwnina phages.

Jumbo phages, which have a genome size of more than 200 kb, have recently been reported for the first time. However, limited information is available regarding their characteristics because few jumbo phages have been isolated. Therefore, in this study, we aimed to isolate and characterize other jumbo phages. We performed comparative genomic analysis of three Erwinia phages (pEa_SNUABM_12, pEa_SNUABM_47, and pEa_SNUABM_50), each of which had a genome size of approximately 360 kb (32.5% GC content). These phages were predicted to harbor 546, 540, and 540 open reading frames with 32, 34, and 35 tRNAs, respectively. Almost all of the genes in these phages could not be functionally annotated but showed high sequence similarity with genes encoded in Serratia phage BF, a member of Eneladusvirus. The detailed comparative and phylogenetic analyses presented in this study contribute to our understanding of the diversity and evolution of Erwinia phage and the genus Eneladusvirus.

Vibrio coralliilyticus (V. coralliilyticus) is a pathogen that causes mass mortality in marine bivalve hatcheries worldwide. In this study, we used a bacteriophage (phage) cocktail to prevent multiple-antibiotic-resistant (MAR) and phage-resistant (PR) V. coralliilyticus infection in Pacific oyster (Crassostreagigas) larvae. To prevent the occurrence of phage-resistant strains and decrease the effect of mono-phage treatment, we prepared a phage cocktail containing three types of V. coralliilyticus-specific phages and tested its prophylactic efficacy against MAR and PR V. coralliilyticus infection. The results of the cell lysis test showed that the phage cocktail showed an excellent bactericidal effect against the MAR and PR variants in contrast to the experimental group treated with two mono phages (pVco-5 and pVco-7). An in vivo test using Pacific oyster larvae also confirmed the preventive effect against MAR and PR variants. In conclusion, the application of the phage cocktail effectively prevented V. coralliilyticus infection in marine bivalve seedling production. Furthermore, it is expected to reduce damage to the aquaculture industry caused by the occurrence of MAR and PR V. coralliilyticus. Therefore, phage cocktails may be used for the control of various bacterial diseases.

Vibrio coralliilyticus is one of the major pathogens causing mass mortality in marine bivalve larvae aquaculture. To prevent and control Vibrio spp. infections in marine bivalve hatcheries, various antibiotics are overused, resulting in environmental pollution and the creation of multi-drug-resistant strains. Therefore, research on the development of antibiotic substitutes is required. In this study, we isolated two bacteriophages (phages) that specifically infected pathogenic V. coralliilyticus from an oyster hatchery and designated them as pVco-5 and pVco-7. Both phages were classified as Podoviridae and were stable over a wide range of temperatures (4–37 °C) and at pH 7.0–9.0. Thus, both phages were suitable for application under the environmental conditions of an oyster hatchery. The two phages showed confirmed significant bactericidal efficacy against pathogenic V. coralliilyticus in an in vitro test. In the in vivo experiment, the phage pre-treated groups of Pacific oyster larvae showed significantly lower mortality against V. coralliilyticus infection than untreated control larvae. The results of the present study suggest that both phages could be used in the artificial marine bivalve seedling industry; not only to prevent pathogenic V. coralliilyticus infection, but also to reduce antibiotic overuse.

Loaches are widely distributed throughout the natural environment and are consumed for medicinal purposes in East Asia. Usually, loaches are cultured in ponds where the water conditions can easily cause bacterial infections. Infections due to bacterial pathogens such as Aeromonas have been well described in cultured loaches; however, there is no report regarding Chryseobacterium infection. This study focused on the elucidation of the pathogenic and antibiotic resistance characteristics of C. cucumeris, SKNUCL01, isolated from diseased loaches (Misgurnus anguillicaudatus). SKNUCL01 forms a biofilm, which is associated with its virulence. Koch’s postulates were satisfied with a lethal dose 50 (LD50) of 8.52 × 107 colony-forming units (CFU)/ml. Abrasion facilitates the mortality of the fish, which makes it a possible infection route for C. cucumeris. The strain showed resistance to nearly all tested antibiotics, such as trimethoprim/sulfamethoxazole, levofloxacin, and ciprofloxacin, formerly considered effective treatments. Phenotypic analyses for antibiotic resistance—the combined disk test, double-disk synergy test, modified Hodge test, and efflux pump inhibition test—revealed that the resistance of SKNUCL01 originated from metallo-beta lactamases (MBLs) and efflux pumps. Our findings provide evidence that could result in a breakthrough against multidrug-resistant Chryseobacterium infection in the aquaculture industry; the antibiotic resistance-related genes can be elucidated through future study.

Vibrio coralliilyticus is known as a coral pathogen that also infects marine bivalve larvae worldwide. It is considered to be one of the major constraints in artificial marine bivalve seed production as it causes mortality. In this study, we first isolated and characterized a high virulent of V. coralliilyticus designated as SNUTY-1 that was the cause of Pacific oyster larvae mortality in Korea. In the pathogenicity test, exposure to 2.14 × 105 CFU/mL for 24 h caused mortality to 88.65 ± 2.4% of the tested healthy Pacific oyster larvae. SNUTY-1 showed anti-microbial resistance to β-lactams, such as penicillins, cephalosporins, and carbapenems. We sequenced and assembled the complete genome of SNUTY-1 (5,842,676 bp), consisting of two chromosomes (Chr I and Chr II) and two plasmids (pSNUTY1 and pSNUTY2). The COG functional analysis confirmed that Chr I had more genes associated with basic cellular functions in comparison to Chr II. The results of the phylogenetic trees based on OrthoANI values indicated that the SNUTY-1 was closely related to V. coralliilyticus strains. SNUTY-1 had a unique plasmid (pSNUTY2), which could mean that the Korean isolate is different from other sequenced V. coralliilyticus strains from different geographical origins. Toxic proteins such as cytolysin/hemolysin and extracellular metalloprotease genes were encoded on Chr I and Chr II of SNUTY-1. These data facilitate the control of V. coralliilyticus infections in aquaculture by providing valuable insights into the biodiversity of this organism and valuable information for the study of virulence factors.

As koi and common carp gain importance in the Korean fish industry, the need for better diagnosis, prevention, and treatment of associated diseases has increased. In June 2019, the first known case of mass mortality involving cyprinid herpesvirus-3 (CyHV-3) and the second involving carp edema virus (CEV) occurred in a koi farm in Jeolla-do, Korea. Notably, the CEV exhibited a closer phylogenetic relationship with certain CEV strains originating from Poland, Germany, and India than with strains originating from China or Japan. Epidemiological studies and detailed surveillance and control for CEV and CyHV-3 are needed along with quarantine inspections.

Aeromonas hydrophila, a Gram-negative bacterium commonly found in aquatic environments, is pathogenic to amphibians, reptiles, and mammals. In human medicine, the clinical symptoms of aeromonad infection include not only gastroenteritis but also extraintestinal infections, such as wounds, cellulitis, and septicemia, in immunocompromised and immunocompetent individuals. In this study, ten red-eyed crocodile skinks (Tribolonotus gracilis) that shared the same space were found dead 7 days after being shipped from Indonesia. The necropsy revealed A. hydrophila to be the causative agent, and the isolates were susceptible to most antibiotics, based on an antimicrobial susceptibility test. Seven virulence factors (act, ast, alt, aerA, fla, gcaT, and ahyB) considered to be associated with virulence were detected by PCR. Microscopic examination revealed several necrotic lesions and melano-macrophage centers in the tissue slides. Reptiles caught in the wild for trade experience captivity stress. Furthermore, in the winter, reptiles are easily exposed to the cold atmosphere. These stresses can negatively impact the immunity of these ectotherms, making them vulnerable to A. hydrophila infections. Therefore, to avoid such opportunistic infections and mortality following exposure to severe stress, medical care is recommended. The studies of alternatives, such as bacteriophage and bacteriocin, are needed for a preventive application.

Background/AimsBecause of the similarities in the clinical presentations of Crohn's disease (CD) and intestinal tuberculosis (ITB), differential diagnosis is critical. Mesenteric adipose tissue hypertrophy and creeping fat are characteristic features of CD. The purpose of this study was to assess the usefulness of visceral fat for the differential diagnosis of CD and ITB.MethodsWe conducted a retrospective review of 50 patients with findings of CD or ITB between January 2005 and July 2008. Abdominal computed tomography (CT) was performed on all subjects during their first evaluation. The abdominal fat area was assessed using quantitative abdominal CT.ResultsThe ratio of visceral fat to total fat (VF/TF) was significantly higher in male CD patients than in male ITB patients. The ratio of visceral fat to subcutaneous fat (VF/SF) was also higher in CD patients than in patients with ITB. For a VF/TF cut-off value of 0.46, the sensitivity and specificity for the diagnosis of CD were 42.1% and 93.3% respectively, with positive and negative predictive values of 88.9% and 56.0%, respectively.ConclusionMeasurement of the abdominal fat area using CT can be clinically useful for the differential diagnosis of CD and ITB.

Pseudomonas species are one of the most prevalent bacterial species globally distributed in forest soil, river water, and human or animal skin. Some species are pathogens or opportunistic pathogens in hospitalized patients, animals, and plants. Various Pseudomonas species, including Pseudomonas putida, P. plecoglossicida, P. aeruginosa, and P. fluorescens, are known fish pathogens; P. fluorescens and P. putida cause severe losses in rainbow trout farming. Therefore, we investigated and isolated the pathogen that is responsible for mortality in a rainbow trout farm in Korea. The isolated bacterium was a strain of P. tructae, which was recently classified in the P. putida group. We performed taxonomical analysis of the bacteria in our previous study. In this study, we investigated the pathogenicity and clinical symptoms of P. tructae and analyzed its genomic characteristics. The pathogenicity of the strain was tested via challenge experiments in healthy rainbow trout and histopathologic analysis of the infected fish. Genome sequence was analyzed to identify the bacterial genes that are involved in antibiotic resistance and virulence. This is the first study reporting P. tructae as an emerging pathogen that is responsible for mortality in rainbow trout fisheries and providing the genome sequence of P. tructae.

Infectious hematopoietic necrosis virus (IHNV), one of the most important pathogenic fish viruses, affects trout fisheries and causes considerable economic losses. Currently, in Korea, more studies on IHNV infection are being reported. However, relatively less data is available on Korean isolates than on those from other countries. Few studies have focused on gene sequence analyses of IHNV glycoprotein (G) gene and almost none have focused on other gene fragments. Therefore, considering the dearth of adequate phylogenetic and genomic studies on Korean IHNV strains because of the lack of data, our study aimed to provide sufficient relevant data by sequencing the complete genome of the IHNV strain SNU1, which was recently isolated from a Korean rainbow trout farm. Moreover, we focused on expanding the perspectives on the phylogenesis of IHNV isolates from Korea and other Asian countries. IHNV was isolated from pooled hematopoietic tissue samples using Epithelioma papulosum cyprinid (EPC) cells, and phylogenetic analysis and genome study were conducted using complete G, N, and nonvirion (NV) gene sequences. Our main achievements were the development of a phylogenetic analytical method based on the NV gene and complete genome sequence analysis of the IHNV strain SNU1, which was compared with other Asian isolate sequences.

Staphylococcal infections are extensively investigated in humans owing to the resistance of staphylococci to diverse antibiotics commonly used in hospitals. The resistance mechanism of methicillin-resistant Staphylococcus aureus has garnered the interest of researchers due to its risk to the global public health. Furthermore, the zoonotic potential of staphylococci has led to increased interest in their transmission mechanism via food, livestock, as well as domestic and wild animals. Although fish are globally consumed, there are only few studies on the potential threat of staphylococcal infection in aquatic animals. In this study, we present the first description of Staphylococcus xylosus infection and its pathogenicity in rainbow trout, which resulted in fish mortality and economic losses in trout fisheries. We focused on the pathogenic role of the bacterium and its influence on rainbow trout based on the clinical symptoms in the eyes. Staphylococcus xylosus infection induced exophthalmia and disrupted the primary immune barrier, which increased the possibility of other secondary bacterial infections in fish under poor conditions, resulting in continuous mortality.

Janthinobacterium spp. are normally considered non-pathogenic, and few pathogenesis-related studies have been reported. Here, we report the first isolation of Janthinobacterium lividum in Korea as a pathogenic bacterium infecting rainbow trout. Mass mortality was observed at one rainbow trout hatchery, and dead fish were necropsied. Gram-negative, nonmotile, rod-shaped bacteria that grew on Cytophaga agar were isolated. A specific violet pigmentation was observed after 7 days of cultivation, and the species were characterized on the basis of the analysis of the 16S rRNA gene. Because no research has focused so far on the pathogenicity of these bacteria, our study was directed to their pathogenic role based on infection-induced histopathology. Examination of stained tissue sections revealed severe renal bacteraemia and tubule degeneration. Other tissue sections, including sections from the liver and the spleen, were relatively clear. The measured half-maximal lethal dose (LD50) was approximately 3 × 105 colony-forming units/fish, suggesting that this bacterium may be an opportunistic pathogen in rainbow trout fisheries. Since the bacterium commonly dwells in soil and most water for rainbow trout fisheries in Korea is supplied from ground water, the bacteria may naturally flow into the aquatic environment. Therefore, recognition of any pathogenic role of J. lividum is important for the prevention of disease in aquaculture.

Red mark syndrome (RMS) is a fish disease caused by the infection of Rickettsial agents, especially affecting rainbow trout (Oncorhynchus mykiss). The disease is prevalent in many countries in Europe (France, Switzerland, Italy, and Slovenia), South America (Chile), North America (USA), and even Asia (Japan). However, it has not been reported in Korean aquaculture. In February 2019, rainbow trout presenting red spot lesions with swollen features on the lateral side of their body were observed at a hatchery in Korea. Fishes showing those clinical signs were fry weighing 25 ± 5 g. Moreover, the fish showing the red spot lesions were found dead, which suggests an outbreak of a mortality-causing disease. The symptoms were similar to those of RMS, and we identified the presence of Rickettsia-like organisms associated with this disease using polymerase chain reaction (PCR), sequencing, histopathologic examination, and transmission electron microscopy. The distinct features of this infection, compared to that in previous reports, were that RMS occurred in small-sized fish and accompanied mortality. Additionally, the presence of the Rickettsia agent was accompanied with outbreak of the disease. Therefore, this is the first report of RMS outbreak in rainbow trout fisheries in Korea.

This article, published in the Annals of Laboratory Medicine, presents a case study of a 72-year-old man who developed tenosynovitis in his right wrist after surgery. The condition was caused by a mold species called Thyridium endophyticum, which is discussed in detail along with its susceptibility to antifungal drugs. The authors suggest that the patient may have been exposed to the mold during agricultural activities. The article provides valuable information for library patrons researching infectious diseases and looking for specific case studies. [Extracted from the article]