ABSTRACT
BACKGROUND: Porcine reproductive and respiratory syndrome virus (PRRSV) is a macrophage-tropic arterivirus with extremely high genetic and pathogenic heterogeneity that causes significant economic losses in the swine industry worldwide. PRRSV can be divided into two species [PRRSV1 (European) and PRRSV2 (North American)] and is usually diagnosed and genetically differentiated into several lineages based on the ORF5 gene, which constitutes only 5% of the whole genome. This study was conducted to achieve nonselective amplification and whole-genome sequencing (WGS) based on a simplified sequence-independent, single-primer amplification (SISPA) technique with next-generation sequencing (NGS), and to genetically characterize Korean PRRSV field isolates at the whole genome level. METHODS: The SISPA-NGS method coupled with a bioinformatics pipeline was utilized to retrieve full length PRRSV genomes of 19 representative Korean PRRSV strains by de novo assembly. Phylogenetic analysis, analysis of the insertion and deletion (INDEL) pattern of nonstructural protein 2 (NSP2), and recombination analysis were conducted. RESULTS: Nineteen complete PRRSV genomes were obtained with a high depth of coverage by the SISPA-NGS method. Korean PRRSV1 belonged to the Korean-specific subtype 1A and vaccine-related subtype 1C lineages, showing no evidence of recombination and divergent genetic heterogeneity with conserved NSP2 deletion patterns. Among Korean PRRSV2 isolates, modified live vaccine (MLV)-related lineage 5 viruses, lineage 1 viruses, and nation-specific Korean lineages (KOR A, B and C) could be identified. The NSP2 deletion pattern of the Korean lineages was consistent with that of the MN-184 strain (lineage 1), which indicates the common ancestor and independent evolution of Korean lineages. Multiple recombination signals were detected from Korean-lineage strains isolated in the 2010s, suggesting natural interlineage recombination between circulating KOR C and MLV strains. Interestingly, the Korean strain GGYC45 was identified as a recombinant KOR C and MLV strain harboring the KOR B ORF5 gene and might be the ancestor of currently circulating KOR B strains. Additionally, two novel lineage 1 recombinants of NADC30-like and NADC34-like viruses were detected. CONCLUSION: Genome-wide analysis of Korean PRRSV isolates retrieved by the SISPA-NGS method and de novo assembly, revealed complex evolution and recombination in the field. Therefore, continuous surveillance of PRRSV at the whole genome level should be conducted, and new vaccine strategies for more efficient control of the virus are needed.
Subject(s)
Porcine Reproductive and Respiratory Syndrome , Porcine respiratory and reproductive syndrome virus , Animals , Genome, Viral , Phylogeny , Porcine Reproductive and Respiratory Syndrome/epidemiology , Porcine respiratory and reproductive syndrome virus/genetics , Recombination, Genetic , SwineABSTRACT
AIMS: This study aimed to investigate the molecular characterization and antimicrobial susceptibility of Corynebacterium pseudotuberculosis from skin abscesses of Korean native black goats (KNBG, Capra hircus coreanae) in South Korea. METHODS AND RESULTS: A total of 83 isolates were recovered from skin abscesses of KNBG. Of these isolates, 74 isolates were identified as C. pseudotuberculosis by phospholipase D (PLD) gene-based PCR assay. Each of the isolates possessed all 18 virulence genes (FagA, FagB, FagC, FagD, SigE, SpaC, SodC, PknG, NanH, OppA, OppB, OppC, OppD, OppF, CopC, NrdH and CpaE). The genetic diversity of C. pseudotuberculosis isolates was assessed by the phylogenetic analysis using the concatenated sequences (3073 bp) of five housekeeping genes (fusA, dnaK, infB, groeL1 and leuA) for investigating their genetic diversity. In the results, the isolates belonged to three groups: group 1 (67 isolates), group 2 (one isolate) and group 3 (six isolates) within biovar ovis. However, the groups exhibited low genetic diversity (0.20%-0.41%). In the antimicrobial susceptibility test, most isolates were susceptible to tetracycline, vancomycin, chloramphenicol, ciprofloxacin, erythromycin, enrofloxacin, cefoxitin, ampicillin, gentamycin, cephalothin and doxycycline, whereas they were not susceptible to cefotaxime, trimethoprim and streptomycin. CONCLUSION: This results suggest the involvement of relatively few clones of C. pseudotuberculosis in Korea. Further, present isolates can threaten public health due to potentially virulent strains with all 18 virulence genes and non-susceptible strains to clinically important antibiotics (CIA) and highly important antibiotics. SIGNIFICANCE AND IMPACT OF THE STUDY: This study is the first to investigate the genetic diversity and potential pathogenicity of C. pseudotuberculosis biovar ovis isolates from skin abscesses of KBNG in South Korea, and could provide useful information in controlling its infections.
Subject(s)
Corynebacterium pseudotuberculosis , Abscess/veterinary , Animals , Anti-Bacterial Agents/pharmacology , Corynebacterium pseudotuberculosis/genetics , Goats/microbiology , Phylogeny , SheepABSTRACT
Yeast vacuoles, lysosomes, are cell organelles that have antimicrobial activity against several bacteria in vitro. Lysosomes have a potential application to the treatment of pathogens such as antibiotics in vivo. Therefore, the in vivo efficacy of lysosomes was examined in a rat infection model against pathogenic Escherichia coli with varying susceptibilities to standard antimicrobial agents. Before in vivo testing, the concentration-dependent safety of lysosomes was confirmed by blood test and histopathology of normal rats. The therapeutic efficacy of lysosomes was examined in terms of the survival of E. coli in infected rat blood. The complete blood count and histopathology results were affected by the lysosomes concentration. In addition, the E. coli growth was inhibited by the initial injection of lysosomes. These results support the use of lysosomes as a bacterial inhibitor of an infected rat model.
Subject(s)
Anti-Bacterial Agents/administration & dosage , Bacteremia/drug therapy , Escherichia coli Infections/drug therapy , Escherichia coli/drug effects , Saccharomyces cerevisiae/chemistry , Vacuoles/chemistry , Animals , Anti-Bacterial Agents/chemistry , Bacteremia/microbiology , Disease Models, Animal , Escherichia coli Infections/microbiology , Humans , Lysosomes/chemistry , Male , Rats , Rats, Sprague-DawleyABSTRACT
Na, K-ATPase is an integral membrane protein complex responsible for maintaining the ionic gradients of Na(+) and K(+) across the plasma membrane and has a variety of cellular functions including neuronal activity. Studies in several organisms have shown that this protein complex regulates multiple aspects of embryonic development and is responsible for the pathogenesis of several human diseases. Here, we report the cloning and expression of Na, K-ATPase α2 (atp1a2) and α3 (atp1a3) subunits during Xenopus development and compare the expression patterns of each subunit. Using in situ hybridization in whole embryos and on sections, we show that all three α subunits are co-expressed in the pronephric kidney, with varying expression in neurogenic derivatives. The atp1a2 has a unique expression in the ependymal cell layer of the developing brain that is not shared with other α subunits. The Na, K-ATPase α1 (atp1a1), and atp1a3 share many expression domains in placode derivatives, including the otic vesicle, lens, ganglion of the anterodorsal lateral line nerve, and ganglia of the facial and anteroventral lateral line nerve and olfactory cells. All the subunits share a common expression domain, the myocardium.
Subject(s)
Gene Expression Regulation, Developmental , Sodium-Potassium-Exchanging ATPase/genetics , Xenopus Proteins/genetics , Xenopus laevis/embryology , Xenopus laevis/genetics , Animals , Organ Specificity , Sodium-Potassium-Exchanging ATPase/metabolism , Transcriptome , Xenopus Proteins/metabolism , Xenopus laevis/metabolismABSTRACT
An African pygmy hedgehog (Atelerix albiventris) was diagnosed as chylous ascites with biliary cirrhosis. Abdomenocentesis revealed a milky fluid with a 324 mg/dl triglyceride level. On serum biochemical examination, the hedgehog had hypoalbuminemia, hypoglycemia, and high blood urea nitrogen. There was no cytologic or genomic evidence of infection, and a blood culture was negative. Histopathologic examination revealed a liver with proliferative bile ducts that were often surrounded by prominent septa of fibrous connective tissue. In the area of ductular reaction, proliferative cells positive for CD66, an embryogenic antigen of epithelial cells, were revealed. The potential association between chylous ascites and liver cirrhosis is undetermined but could be an aspect of future study. This is the first description of chylous ascites in a hedgehog.
Subject(s)
Chylous Ascites/veterinary , Hedgehogs , Liver Diseases/veterinary , Animals , Chylous Ascites/diagnosis , Chylous Ascites/pathology , Liver Diseases/diagnosis , Liver Diseases/pathology , MaleABSTRACT
With the ongoing global warming-induced climate change, there has been a surge in vector-borne diseases, particularly tick-borne diseases (TBDs). As the population of companion animals grows, there is growing concern from a One Health perspective about the potential for these animals to spread TBDs. In this study, ticks were collected from companion animals and the surrounding environment in Daejeon Metropolitan City, Korea, using flagging and dragging, and CO2 trap methods. These ticks were then subjected to conventional (nested) PCR for severe fever with thrombocytopenia syndrome virus (SFTSV), Anaplasma spp., Ehrlichia spp., and Borrelia spp. We identified a total of 29,176 ticks, consisting of three genera and four species: H. longicornis, H. flava, I. nipponensis, and A. testudinarium. Notably, H. longicornis was the predominant species. The presence of A. testudinarium suggested that the species traditionally found in southern regions are migrating northward, likely as a result of climate change. Our PCR results confirmed the presence of all four pathogens in both companion animals and the surrounding environment, underscoring the potential for the indirect transmission of tick-borne pathogens to humans through companion animals. These findings emphasize the importance of the ongoing surveillance of companion animals in the management and control of TBDs.
ABSTRACT
Porcine epidemic diarrhea (PED), caused by the porcine epidemic diarrhea virus (PEDV), emerges annually in several Asian countries. Its major symptoms include watery diarrhea, vomiting, anorexia, and dehydration. PED outbreaks incur significant economic losses. The efficacy of vaccines is limited by viral mutations and insufficient intestinal mucosal immunity. Therefore, new vaccines against these recent variants are urgently needed. Herein, we isolated and genetically characterized a novel Korean PEDV strain using NGS. Comparative genomic analysis demonstrated that the CKK1-1 strain belonged to genogroup 2. The isolated strain was cultured in sodium-glycochenodeoxycholic acid for 180 passages. Typically, PEDV isolation and passage require proteases, such as trypsin. However, the CKK1-1 strain adapted to this atypical culture condition, achieving a high titer of 8.83 Ā± 0.14 log TCID50/mL. In vitro biological analysis revealed no cell syncytium formation without trypsin; however, a cell-lysis-type cytopathic effect was noted. Notably, pathogenicity evaluation showed that CKK1-1 p0 exhibited naturally weakened virulence in five-day-old piglets, while piglets administered with CKK1-1 p180 exhibited 100% survival and reduced clinical symptoms. Collectively, our data demonstrate that this Korean PEDV strain, attenuated through atypical culture conditions with Na-glycochenodeoxycholic acid, has potential as a vaccine candidate, providing valuable insights into the genetic variation in and pathogenicity of PEDV.
Subject(s)
Coronavirus Infections , Porcine epidemic diarrhea virus , Swine Diseases , Animals , Porcine epidemic diarrhea virus/genetics , Porcine epidemic diarrhea virus/isolation & purification , Porcine epidemic diarrhea virus/pathogenicity , Porcine epidemic diarrhea virus/classification , Swine , Republic of Korea , Swine Diseases/virology , Coronavirus Infections/veterinary , Coronavirus Infections/virology , Virulence , Phylogeny , Genome, Viral , Chlorocebus aethiops , Vero CellsABSTRACT
Porcine epidemic diarrhea (PED) outbreaks occur annually in the Republic of Korea. The complete genome sequence of the PED virus isolate CKK1-1 obtained from an infected pig was determined. The genome is 28,037 nt long, excluding the poly(A) tail, and contains seven open reading frames flanked by two untranslated regions.
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This retrospective study reports the isolation and characterization of Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) from a household cat in South Korea. The cat, which was presented with respiratory symptoms, was identified during a retrospective analysis of samples collected between April 2021 and March 2022. Genomic sequencing revealed that the isolated virus belonged to the Omicron variant (BA.1), coinciding with its global emergence in early 2022. This case study provides evidence for the potential of direct human-to-cat transmission of the Omicron variant in South Korea during its period of widespread circulation. Our findings underscore the importance of continuous monitoring of SARS-CoV-2 in both human and animal populations to track viral evolution and potential spillover events.
Subject(s)
COVID-19 , SARS-CoV-2 , Republic of Korea/epidemiology , Humans , SARS-CoV-2/genetics , SARS-CoV-2/classification , SARS-CoV-2/isolation & purification , COVID-19/virology , COVID-19/epidemiology , COVID-19/transmission , Animals , Cats , Retrospective Studies , Phylogeny , Genome, Viral , Cat Diseases/virology , Cat Diseases/epidemiologyABSTRACT
The Korean water deer (WD), a predominant wildlife species in South Korea, is listed as vulnerable by the IUCN Red List. Despite belonging to the same family, Cervidae, WD show significantly fewer adult ixodid tick infestations compared to roe deer (RD). Ticks, which cannot fly, engage in questing behavior in natural environments to latch onto hosts. They detect signals like body temperature and host skin chemicals to navigate through the hair coat to the preferred epidermis. In light of this, we performed an extensive comparative study of the skin tissue and hair characteristics of both deer species, focusing on elements contributing to the reduced tick bite incidence in WD. Remarkably, WD exhibited more prominent blood vessels, sebaceous glands, and sweat glands, which are crucial for skin barrier functions (p < 0.005). Moreover, WD had irregular scale patterns on their hair cuticles and possessed hair that was significantly stiffer and 2.83 times thicker than that of RD (p < 0.001). These characteristics potentially impede ticks from reaching the epidermis hair in WD and RD in the context of tick bite prevention. Further investigations in this area could enhance our understanding of tick-host dynamics and contribute to developing preventive measures against tick-borne diseases in other deer species.
ABSTRACT
Caseous lymphadenitis (CLA) is a chronic and subclinical bacterial disease of ruminants caused by Corynebacterium pseudotuberculosis (C. pseudotuberculosis) infection. Until 2014, there were no reports of CLA outbreaks in South Korea; however, the prevalence of CLA cases has steadily increased. In this study, we used recently obtained field isolates to develop the first inactivated CLA vaccine in South Korea and evaluated it in various animal models. The inactivated vaccine was evaluated for virulence and effectiveness. Mice were tested for virulence and immunization challenges, and guinea pigs and Korean Native Black Goats (KNBGs) evaluated various vaccine concentrations to determine the optimal dose and effectiveness. In the case of KNBGs, clinical symptoms were not observed after vaccination. In addition, CLA-specific IgG was detected at a significantly (p < 0.05) high level and was maintained. In histopathological evaluations, inflammation was predominantly observed in the prefemoral lymph nodes in the non-vaccinated+CHAL group. The genetic diversity of C. pseudotuberculosis, which has become widespread in South Korea, is less than 0.5% our vaccine is expected to prevent infection by a wide range of strains effectively. In summary, our CLA vaccine can potentially prevent CLA and foster the growth of South Korea's domestic KNBG industry.
ABSTRACT
Korean native cattle are highly valued for their rich marbling and flavor. Nonetheless, endeavors to enhance marbling levels can result in obesity, a prevalent contributor to fat necrosis. Fat necrosis is characterized by the formation of necrotic fat masses in the abdominal cavity, which physically puts pressure on affected organs, causing physical torsion or obstruction, resulting in death and consequent economic loss. Pancreatic injuries or diabetes mellitus were reported as factors of fat necrosis in humans; however, the pathogenesis in animals has not been established. In this study, we identified fat necrosis in a 6-month-old Korean native cow and investigated its potential underlying causes. Serum samples were utilized for a microarray analysis of bovine miRNA. Comparative examination of miRNA expression levels between cattle afflicted with fat necrosis and healthy cattle unveiled notable variances in 24 miRNAs, such as bta-miR-26a, bta-miR-29a, bta-miR-30a-5p and bta-miR-181a. Upon conducting miRNA-mediated KEGG pathway analysis, several pathways including the prolactin signal pathway, insulin resistance, autophagy, the insulin-signaling pathway and the FoxO-signaling pathway were found to be significantly enriched in the calf affected by fat necrosis. As a result, this study potentially indicates a potential connection between fat necrosis and diabetes in Korean native cattle.
ABSTRACT
Porcine epidemic diarrhea (PED) is a highly contagious disease that has been reported annually in several Asian countries, causing significant economic losses to the swine livestock industry. Although vaccines against the porcine epidemic diarrhea virus (PEDV) are available, their efficacy remains questionable due to limitations such as viral genome mutation and insufficient intestinal mucosal immunity. Therefore, the development of a safe and effective vaccine is necessary. In this study, a virulent Korean strain of PEDV, CKT-7, was isolated from a piglet with severe diarrhea, and six different conditions were employed for serial passage of the strain in a cell culture system to generate effective live attenuated vaccine (LAV) candidates. The characteristics of these strains were analyzed in vitro and in vivo, and the CKT-7 N strain was identified as the most effective vaccine candidate, with a viral titer peak of 8.67 Ā± 0.29 log10TCID50/mL, and no mortality or diarrhea symptoms were observed in five-day-old piglets. These results indicate that LAV candidates can be generated through serial passage with different culture conditions and provide valuable insights into the development of a highly effective LAV against PEDV.
ABSTRACT
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections have been frequently reported in companion dogs and cats worldwide during the ongoing coronavirus disease. However, RT-qPCR methods developed for humans have been used for the diagnosis of SARS-CoV-2 infections in suspected companion dogs and cats owing to the lack of the companion animal-tailored methods. Therefore, we developed a multiplex RT-qPCR (mRT-qPCR) using newly designed primers and probes targeting RdRp and N genes of all currently circulating SARS-CoV-2 variants as well as the canine or feline 16S rRNA gene as an endogenous internal positive control (EIPC) for reliable diagnosis of SARS-CoV-2 infection from suspected dogs and cats. The developed mRT-qPCR assay specifically detected the target genes of SARS-CoV-2 but no other canine or feline pathogens. Furthermore, canine and feline EIPCs were stably amplified by mRT-qPCR in samples containing canine- or feline-origin cellular materials. This assay has high repeatability and reproducibility, with an optimal limit of detection (<10 RNA copies per reaction) and coefficients of variation (<1.0%). The detection rate of SARS-CoV-2 of the developed mRT-qPCR was 6.6% for canine and feline nasopharyngeal samples, which was consistent with that of a commercial mRT-qPCR kit for humans. Collectively, the newly developed mRT-qPCR with canine and feline EIPC can efficiently diagnose and evaluate the viral load in field specimens and will be a valuable tool for etiological diagnosis, epidemiological study, and controlling SARS-CoV-2 infections in canine and feline populations.
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The COVID-19 pandemic is caused by the zoonotic SARS-CoV-2 virus. A wide range of animals that interact with humans have been investigated to identify potential infections. As the extent of infection became more apparent, extensive animal monitoring became necessary to assess their susceptibility. This study analyzed nasal swabs and blood samples collected from randomly selected Korean native cattle and Korean native black goats. The tests conducted included real-time qPCR to detect SARS-CoV-2 antigens, an ELISA to detect antibodies, and a plaque reduction neutralization test (PRNT) to determine the presence of neutralizing antibodies. Among the 1798 animals tested (consisting of 1174 Korean native cattle and 624 Korean native black goats), SARS-CoV-2 viral RNA was detected in one Korean native cattle and one Korean native black goat. ELISA testing revealed positive results for antibodies in 54 Korean native cattle (4.60%) and 16 Korean native black goats (2.56%), while PRNTs yielded positive results in 51 Korean native cattle (4.34%) and 14 Korean native black goats (2.24%). The presence of SARS-CoV-2 antigens and/or antibodies was identified in animals on farms where farmworkers were already infected. It is challenging to completely rule out the possibility of reverse zoonotic transmission from humans to livestock in Korea, although the transmission is not to the same extent as it is in highly susceptible animal species like minks, cats, and dogs. This is due to the limited geographical area and the dense, intensive farming practices implemented in these regions. In conclusion, continuous viral circulation between humans and animals is inevitable, necessitating ongoing animal monitoring to ensure public health and safety.
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The factors that influence the pathogenicity of African swine fever (ASF) are still poorly understood, and the host's immune response has been indicated as crucial. Although an increasing number of studies have shown that gut microbiota can control the progression of diseases caused by viral infections, it has not been characterized how the ASF virus (ASFV) changes a pig's gut microbiome. This study analyzed the dynamic changes in the intestinal microbiome of pigs experimentally infected with the high-virulence ASFV genotype II strain (N = 4) or mock strain (N = 3). Daily fecal samples were collected from the pigs and distributed into the four phases (before infection, primary phase, clinical phase, and terminal phase) of ASF based on the individual clinical features of the pigs. The total DNA was extracted and the V4 region of the 16 s rRNA gene was amplified and sequenced on the Illumina platform. Richness indices (ACE and Chao1) were significantly decreased in the terminal phase of ASF infection. The relative abundances of short-chain-fatty-acids-producing bacteria, such as Ruminococcaceae, Roseburia, and Blautia, were decreased during ASFV infection. On the other hand, the abundance of Proteobacteria and Spirochaetes increased. Furthermore, predicted functional analysis using PICRUSt resulted in a significantly reduced abundance of 15 immune-related pathways in the ASFV-infected pigs. This study provides evidence for further understanding the ASFV-pig interaction and suggests that changes in gut microbiome composition during ASFV infection may be associated with the status of immunosuppression.
ABSTRACT
Newborn piglets are susceptible to a highly contagious enteritis caused by the porcine epidemic diarrhea virus (PEDV), associated with high levels of mortality worldwide. There is pressing need for a rapid, safe, and cost-effective vaccine to safeguard pigs from getting infected by PEDV. PEDV belongs to the coronavirus family and is characterized by high levels of mutability. The primary goal of a PEDV vaccine is to provide immunity to newborn piglets through vaccination of sows. Plant-based vaccines are becoming more popular because they have low manufacturing costs, are easily scalable, have high thermostability, and a long shelf life. This is in contrast to conventional vaccines which include inactivated, live, and/or recombinant types that can be expensive and have limited ability to respond to rapidly mutating viruses. The binding of the virus to host cell receptors is primarily facilitated by the N-terminal subunit of the viral spike protein (S1), which also contains several epitopes that are recognized by virus-neutralizing antibodies. As a result, we generated a recombinant S1 protein using a plant-based vaccine platform. We found that the recombinant protein was highly glycosylated, comparable to the native viral antigen. Vaccination of pregnant sows at four and two weeks before farrowing led to the development of humoral immunity specific to S1 in the suckling piglets. In addition, we noted significant viral neutralization titers in both vaccinated sows and piglets. When challenged with PEDV, piglets born from vaccinated sows displayed less severe clinical symptoms and significantly lower mortality rates compared to piglets born from non-vaccinated sows.
ABSTRACT
PATIENTS: The patient was a 32-year-old man who underwent amalgam restoration of the mandibular right second molar. An amalgam restoration fracture was diagnosed by intraoral optical coherence tomography (OCT), and pulp exposure was examined during cavity preparation. Subsequently, a definitive ceramic restoration was fabricated, and the marginal fit in the oral cavity was evaluated using the OCT system. DISCUSSION: The existing OCT system cannot acquire images inside the oral cavity because of the large probe size. However, the proposed intraoral OCT system can access the prostheses in the mandibular right second molar. Therefore, dental diagnosis for restoration treatment with dental prosthesis fracture, marginal gap, and pulp exposure after tooth preparation is possible using the proposed intraoral OCT system. CONCLUSIONS: The use of the intraoral OCT system improved dental diagnosis by allowing the dentist to confirm quantitative values through cross-sectional images, rather than that by determining a treatment plan after visual dental diagnosis.
Subject(s)
Inlays , Tomography, Optical Coherence , Humans , Adult , Tomography, Optical Coherence/methods , Molar , Dental Cavity Preparation , MouthABSTRACT
A 3-year-old female Miniature Schnauzer dog with a week-long history of generalized intention tremor and progressive weight loss for several months was admitted. Mild anemia, fever, splenomegaly, aseptic cerebral meningitis and systemic lymph nodes enlargement were examined through erythrogram, ultrasonography, computed tomography and magnetic resonance imaging. Mycobacterium bovis was identified via molecular microbiology having the same molecular type as that of isolates from a cattle farm previously identified. However, the dog was raised in a city. The M. bovis had multidrug resistance (MDR)-bearing mutations in both katG and rpoB genes toward first-line antibiotics. To the best of our knowledge, this is the first report describing an MDR M. bovis infection of a dog in Korea.
Subject(s)
Mycobacterium bovis , Mycobacterium tuberculosis , Animals , Antitubercular Agents/therapeutic use , Cattle , Dogs , Female , Microbial Sensitivity Tests/veterinary , Mutation , Mycobacterium bovis/geneticsABSTRACT
Foot-and-mouth disease (FMD) is one of the most contagious diseases in cloven hoof animals. Vaccination can prevent or control FMD, and vaccine antigens should be matched against circulating viruses. According to phylogenetic analyses, field isolates in this region belonged to genotype V and showed low genetic similarity with the Asia1 Shamir vaccine, the OIE-recommended vaccine strain. In this study, we investigated whether pigs vaccinated with the Asia1 Shamir vaccine could be protected from challenges with the Asia1/MOG/05 virus, one of the genotype V field isolates. Eight pigs were divided into either vaccinated or nonvaccinated control groups. After two vaccinations with Asia1 Shamir, both groups of pigs were challenged with the Asia1/MOG/05 field isolate at 2 weeks after the second vaccination. In the control group, symptoms appeared at 2 days post-infection (dpi). The clinical sign score peaked at 4 dpi, and this coincided with virus shedding through nasal discharge. Neutralizing antibody titers peaked at 17 dpi. In the vaccinated group, clinical signs were delayed compared with the control group, and the highest score was shown at 10 dpi accompanied with virus nasal shedding, which peaked at 11 dpi. Neutralizing antibodies were induced 2 weeks after the second vaccination and peaked at 17 dpi. In conclusion, Asia1 Shamir vaccination in pigs provided partial protection from Asia1/MOG/05 virus infection.