• Animal Bioscience
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• v.34 no.4
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• pp.734-742
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• 2021

Objective: The present study aimed to investigate the occurrence and species of coagulase-positive staphylococci (CoPS) and coagulase-negative staphylococci (CoNS) in retail pork meat samples collected during nationwide monitoring. The staphylococcal isolates were characterized for antimicrobial and zinc chloride resistance and enterotoxigenic potential. Methods: A total of 260 pre-packaged pork meat samples were collected from 35 retail markets in 8 provinces in Korea for isolation of staphylococci. Antimicrobial and zinc chloride resistance phenotypes, and genes associated with the resistance phenotypes were determined on the isolates. Furthermore, the presence and distribution of 19 staphylococcal enterotoxin (SE) genes and enterotoxin-like genes among the pork-associated staphylococci were determined by multiplex polymerase chain reaction-based assays using the specific primer sets. Results: A total of 29 staphylococcal strains (29/260, 11.1%) were isolated from samples of retail pork meat, 24 (83%) of which were CoNS. The four CoNS species identified were S. saprophyticus (n = 16, 55%), S. sciuri (n = 3, 10%), S. warneri (n = 3, 10%), and S. epidermidis (n = 2, 7%). Among the 29 isolates, four methicillin-resistant CoNS (MR-CoNS; three S. sciuri and one S. epidermidis) and one methicillin-resistant CoPS (MR-CoPS; one S. aureus) were identified. In addition, a relatively high level of tetracycline (TET) resistance (52%) was confirmed in CoNS, along with a predominant distribution of tet(K). The most prevalent SEs were sep (45%), and sen (28%), which were carried by 81% of S. saprophyticus. Conclusion: These findings suggest that CoNS, especially S. saprophyticus strains, in raw pork meat could be a potential risk factor for staphylococcal food poisoning (SFP), and therefore, requires further investigation to elucidate the role of SEls in SFP and virulence of the pathogen. Our results also suggest that CoNS from raw pork meat may act as a source for transmission of antimicrobial resistance genes such as staphylococcal cassette chromosome mec and tet(K).

• Journal of Apiculture
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• v.34 no.1
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• pp.39-46
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• 2019

BQCV multi-point PCR was developed as a rapid multiplex detection method for BQCV, one of the viral pathogens of honeybees. It could detect BQCV specific genes qualitative as well as quantitative detection based on ultra-rapid PCR. Three primer pairs (RNA dependent RNA polymerase, capsid protein, 3C like protease) were specifically designed for accurate the detection and were optimized for minimizing the detection time and increasing the sensitivity. Our advanced diagnostic system have the accuracy by lowering the concern about the variation in the BQCV detection site. In addition, it should be an opportunity to identify mutations that are mixed with other viruses.

• Journal of Plant Biotechnology
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• v.49 no.3
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• pp.193-206
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• 2022

Astringent persimmon (Diospyros kaki Thunb.) is an important fruit crop in Korea; it possesses significant medicinal potential. However, knowledge regarding the pathogens affecting this crop, particularly, viruses and viroids, is limited. In the present study, reverse transcription-polymerase chain reaction (RT-PCR) and high-throughput transcriptome sequencing (HTS) were used to investigate the viruses and viroids infecting astringent persimmons cultivated in Korea. A one-step multiplex RT-PCR (mRT-PCR) method for the simultaneous detection of the pathogens was developed by designing species-specific primers and selecting the primer pairs via combination and detection limit testing. Seven of the sixteen cultivars tested were found to be infection-free. The RT-PCR and HTS analyses identified two viruses and one viroid in the infected samples (n = 51/100 samples collected from 16 cultivars). The incidence of single infections (n = 39/51) was higher than that of mixed infections (n = 12/51); the infection rate of the Persimmon cryptic virus was the highest (n = 31/39). Comparison of the monoplex and mRT-PCR results using randomly selected samples confirmed the efficiency of mRT-PCR for the identification of pathogens. Collectively, the present study provides useful resources for developing disease-free seedlings; further, the developed mRT-PCR method can be extended to investigate pathogens in other woody plants.

• Research in Plant Disease
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• v.28 no.1
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• pp.54-56
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• 2022

A peanut plant showing wilt and browned symptom was found in the field of Gochang, Korea, in July 2021. The symptomatic peanut plant was collected from the field and isolation of the pathogen caused the wilt symptom was performed using the collected sample on TZC media. The dominated colony on media was isolated colony on media was isolated and subcultured of purification. The pure cultured bacteria was identified as Ralstonia solanacearum by sequencing of 16S rRNA gene. Multiplex polymerase chain reaction using phylotype-specific primer set identified isolate as phylotype I (R. pseudosolanacearum). Phylogenetic tree was constructed based on 16S rRNA sequence and it was closed with R. pseudosolanacearum. Pathogenicity of the isolates was assessed by soil drenching inoculation on 4-week-old peanut plant. The wilt symptom was successfully reproduced by inoculation of the isolates after 14 days. This is first report of bacterial wilt caused by R. pseudosolanacearum on peanut in Korea.

• Journal of Veterinary Science
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• v.21 no.2
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• pp.22.1-22.9
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• 2020

Rabid raccoon dogs (Nyctereutes procyonoides koreensis) have been responsible for animal rabies in South Korea since the 1990s. A recombinant rabies vaccine strain, designated as ERAGS, was constructed for use as a bait vaccine. Therefore, new means of differentiating ERAGS from other rabies virus (RABV) strains will be required in biological manufacturing and diagnostic service centers. In this study, we designed two specific primer sets for differentiation between ERAGS and other RABVs based on mutation in the RABV glycoprotein gene. Polymerase chain reaction analysis of the glycoprotein gene revealed two DNA bands of 383 bp and 583 bp in the ERAGS strain but a single DNA band of 383 bp in the field strains. The detection limits of multiplex reverse transcription polymerase chain reaction (RT-PCR) were 80 and 8 FAID₅₀/reaction for the ERAGS and Evelyn-Rokitnicki-Abelseth strains, respectively. No cross-reactions were detected in the non-RABV reference viruses, including canine distemper virus, parvovirus, canine adenovirus type 1 and 2, and parainfluenza virus. The results of multiplex RT-PCR were 100% consistent with those of the fluorescent antibody test. Therefore, one-step multiplex RT-PCR is likely useful for differentiation between RABVs with and those without mutation at position 333 of the RABV glycoprotein gene.

• Research in Plant Disease
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• v.29 no.1
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• pp.94-99
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• 2023

Blueberry red ringspot virus (BRRSV) and blueberry scorch virus (BlScV) are included in the quarantine virus list managed by the Korean Animal and Plant Quarantine Agency. A multiplex polymerase chain reaction (PCR) assay with an internal control was developed for the simultaneous detection of both viruses. The specific primers used here were designed based on the highly conserved regions of the genomic sequences of each virus, obtained from the National Center for Biotechnology Information nucleotide databases. The primers were designed to amplify a partial sequence within coat protein (CP) for detecting BRRSV and a partial sequence within the CP-16 kDa for detecting BlScV. 18S ribosomal RNA (rRNA) was used as internal control, and the primer set used in a previous study was modified in this study for detecting 18S rRNA. Each conventional PCR using the BRRSV, BlScV, and 18S rRNA primers exhibited a sensitivity of approximately 1 fg plasmid DNA. The multiplex PCR assay using the BRRSV, BlScV, and 18S rRNA primers was effective in simultaneously detecting the two viruses and 18S rRNA with a sensitivity of 1 fg plasmid DNA, similar to that of conventional PCR assays. The multiplex PCR assay developed in this study was performed using 14 blueberry cultivars grown in South Korea. BRRSV and BlScV were not detected, but 18S rRNA was all detected in all the plants tested. Therefore, our optimized multiplex PCR assay could simultaneously detect the two viruses and 18S rRNA in field samples collected from South Korea in a time-efficient manner. This approach could be valuable in crop protection and plant quarantine management.

• Journal of Marine Life Science
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• v.2 no.2
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• pp.83-89
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• 2017

In abalones, interspecific hybridization has been suggested as a possible means to increase production and desired traits for the industry. In Korea, Haliotis gigantea is considered a species with a larger size and higher temperature tolerance than H. discus hannai. However, H. discus hannai is considered the most valuable and popular fishery resource due to its better acceptance and higher market prices. Thus, viable interspecific hybrids have been produced by artificial inseminating H. gigantea eggs with H. discus hannai sperm. However, the reciprocal hybrid cross was not successful. In this study, the hybridity and the growth and thermal tolerance performance of the interspecific hybrids were examined. A combination of various assays revealed maximum growth occurrence at 21℃ and the higher growth rate in the hybrids than that of H. discus hannai parent. In addition, the growth and survival at high-temperature (28℃) of the hybrids was equivalent to that of the highly tolerant H. gigantea parent, suggesting new possibilities to overcome the mass mortality in H. discus hannai during high temperature periods of summer season in Korea. Furthermore, the induced interspecific hybrid status was confirmed by the presence of species-specific bands for each parental species of the random amplified polymorphic DNA (RAPD) profiles using universal rice primer (URP), which could be used as speciesspecific markers to distinguish the hybrids and their parental species.

• Clinical and Experimental Reproductive Medicine
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• v.50 no.4
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• pp.253-261
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• 2023

Objective: Azoospermia (the total absence of sperm in the ejaculate) affects approximately 10% of infertile males. Despite diagnostic advances, azoospermia remains the most challenging issue associated with infertility treatment. Our study evaluated transition nuclear protein 2 (TNP2) and synaptonemal complex protein 3 (SYCP3) polymorphisms, azoospermia factor a (AZFa) microdeletion, and gene expression levels in 100 patients with azoospermia. Methods: We investigated a TNP2 single-nucleotide polymorphism through polymerase chain reaction (PCR) restriction fragment length polymorphism analysis using a particular endonuclease. An allele-specific PCR assay for SYCP3 was performed utilizing two forward primers and a common reverse primer in two PCR reactions. Based on the European Academy of Andrology guidelines, AZFa microdeletions were evaluated by multiplex PCR. TNP2, SYCP3, and the AZFa region main gene (DEAD-box helicase 3 and Y-linked [DDX3Y]) expression levels were assessed via quantitative PCR, and receiver operating characteristic curve analysis was used to determine the diagnostic capability of these genes. Results: The TNP2 genotyping and allelic frequency in infertile males did not differ significantly from fertile volunteers. In participants with azoospermia, the allelic frequency of the SYCP3 mutant allele (C allele) was significantly altered. Deletion of sY84 and sY86 was discovered in patients with azoospermia and oligozoospermia. Moreover, SYCP3 and DDX3Y showed decreased expression levels in the azoospermia group, and they exhibited potential as biomarkers for diagnosing azoospermia (area under the curve, 0.722 and 0.720, respectively). Conclusion: These results suggest that reduced SYCP3 and DDX3Y mRNA expression profiles in testicular tissue are associated with a higher likelihood of retrieving spermatozoa in individuals with azoospermia. The homozygous genotype TT of the SYCP3 polymorphism was significantly associated with azoospermia.

• Journal of Food Hygiene and Safety
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• v.29 no.4
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• pp.347-355
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• 2014

In this study, the detection method was developed using molecular biological technique to distinguish authenticity of animal raw materials. The genes for distinction of species about animals targeted at Cytochrome c oxidase subunit I (COI), Cytochrome b (Cytb), and 16S ribosomal RNA (16S rRNA) genes in mitochondrial DNA. The species-specific primers were designed by that Polymerase Chain Reaction (PCR) product size was around 200 bp for applying to processed products. The target 24 raw materials were 2 species of domestic animals, 6 species of poultry, 2 species of freshwater fishes, 13 species of marine fishes and 1 species of crustaceans. The results of PCR for Rabbit, Fox, Pheasant, Domestic Pigeon, Rufous Turtle Dove, Quail, Tree Sparrow, Barn Swallow, Catfish, Mandarin Fish, Flying Fish, Mallotus villosus, Pacific Herring, Sand Lance, Japanese Anchovy, Small Yellow Croaker, Halibut, Jacopever, Skate Ray, Ray, File Fish, Sea Bass, Sea Urchin, and Lobster raw materials were confirmed 113 bp ~ 218 bp, respectively. Also, non-specific PCR products were not detected in compare species by species-specific primers. The method using primers developed in this study may be applied to distinguish an authenticity of food materials included animal raw materials for various processed products.

• Horticultural Science & Technology
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• v.32 no.2
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• pp.217-226
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• 2014

Root-knot symptoms were found on a commercial tomato cultivar carrying Mi, a resistance gene to root-knot nematodes including Meloidogyne incognita, M. arenaria, and M. javanica in 2012 at Buyeo, Chungnam Province in Korea. The isolate was identified as M. incognita based on molecular analyses using two species-specific primer sets. Pathogenicity of the isolate on one susceptible and three resistant tomato cultivars to the root-knot nematodes was tested. The nematode isolate showed strong pathogenicity on all the tested cultivars at all tested incubation temperatures. In addition, resistance degree of 33 commercial tomato cultivars, 8 susceptible and 25 resistant cultivars to root-knot nematodes, was also tested. Plants were determined as resistant when they suppressed the nematode reproduction. All the cultivars demonstrated strong susceptibility to the nematode regardless of resistance of the tomato cultivars. To our knowledge, this is the first report on the occurrence of Mi infecting M. incognita isolate in Korea. On the other hand, to construct an efficient screening method for selecting resistant breeding source to the nematode isolate, root-knot development of M. incognita on four tomato cultivars according to several conditions such as inoculum concentration, plant growth stage, and incubation period after transplant was investigated. Reproduction of the nematode on all the tested cultivars according to inoculum concentration increased in a dose-dependent manner. Except for inoculum concentration, there was no significant difference in reproduction level of the cultivars according to the other tested conditions. On the basis of the results, we suggest an efficient screening method for new resistant tomato to the nematode isolate.