• Korean Journal of Veterinary Research
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• v.51 no.2
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• pp.107-115
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• 2011

Theileria (T.) buffeli (formerly T. sergenti/T. orientalis) is the major hemo-protozoan distributed in the Far East Asian countries such as Korea, China and Japan. It is responsible for the clinical symptoms of anorexia, ateliosis, anemia, fever and icterus. It also causes abortion and sudden death under severe cases, resulting in economic losses for many livestock farms. The objective of this study was to analyze the genetic diversity of the major surface protein (Msp) gene in T. buffeli in Holstein in Korea, and we characterized the association of the diversification of the Msp gene and its relationship with the pathogenicity of Theileria. For this, complete blood counts and Theileria PCR sequence analysis were performed from 57 Holstein in Jeju Island. A total of 26 PCR positive Holstein (16 anemic and 10 non-anemic) were then randomly selected based on 18s rRNA sequence typing of the Theileria Msp gene. The DNA sequence of the T. buffeli Msp gene in Holstein showed 99.0%, 99.2%, 99.9%, 99.5%, 98.7%, 98.4% and 98.4% homology with T. sergenti, Theileria spp., T. sergenti, Theileria spp., Theileria spp., Theileria spp. and Theileria spp., respectively. The result showed a genetic variation of 57.7% (type I), 3.8% (type II), 15.4% (type III), 7.7% (type IV), 13.5% (type V) and 1.9% (type VI). Type I is the most frequent type in both anemic and non-anemic Holstein while type II was found in only non-anemic Holstein. This results of our study help confirm the diversity of Msp gene types and demonstrate that the gene type distribution of Msp genes varies among Theileria-infected Holstein in Jeju Island.

• Journal of Microbiology
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• v.43 no.5
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• pp.417-423
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• 2005

In this study, the nematode-trapping fungus, Monacrosporium sphaeroides, was transformed with a plasmid harboring the hygromycin B phosphotransferase gene, via restriction enzyme-mediated integration (REMI). Frequencies of up to 94 transformants ${\mu}g^{-1}$ per linearized plasmid DNA were obtained by optimizing the PEG concentration, as well as the category and quantity of the added restriction enzyme. $90\%$ of the transformants were determined to be stable for drug resistance when 20 randomly selected transformants were tested. Southern analyses revealed that the transforming DNA was integrated into the M. sphaeroides genome either with or without rearrangement. Five mitotic stable mutant strains were obtained using this approach, all of which had been altered with regard to sporulation capacity and pathogenicity toward nematodes. Southern blot analyses of the five mutants revealed that foreign plasmid DNA had integrated into the genome. Three of the mutants, Tms2316, Tms3583 and Tms1536, exhibited integration at a single location, whereas the remaining two, Tms32 and Tms1913, manifested integration at double or multiple locations. Our results suggest that the transformation of M. sphaeroides via REMI will facilitate insertional mutagenesis, the functional analysis of a variety of genes, and the tagging or cloning of genes of interest.

• Korean Journal Plant Pathology
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• v.10 no.1
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• pp.54-60
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• 1994

Incidence of Rhizoctonia blight ranged from 22.2% to 100% in the golf courses at six geographical locations in Korea from 1989 to 1993. Rhizoctonia blight occurred more severly in southern area than in northern area. Fifty seven isolates of Rhizoctonia solani obtained from diseased parts of zoysiagrasses were grouped to AG2-2 by anastomosis test. Pathogenicity testes revealed that this pathogen was strongly pathogenic to Korean lawngrasses(Zoysia japonica, Z. matrella, Z. tenuifolia), but not pathogenic to creeping bentgrass(Agrostis palustris), bermuldagrass(Cynodon dactylon), Kentucky bluegrass(Poa pratensis), perennial ryegrass(Lolium prenne), and creeping red fescue(Festuca rubra subsp. rubra L.). The isolation frequency of R. solani AG2-2 fro sheaths of the infected plants was the highest by 91.67%, and that from stolons and roots was 11.13% and 5.63% respectively. The pathogen was not isolated from the leaves. Population density of R. solani in the lawn of large circular patch was highest on surface soils down to 1 cm deep with the value of 4.9$\times$104 (CFU/g soil), but below 1 cm population density decreased sharply down to 0.8~9.8$\times$103 (CFU/g soil). Horizontal distribution of propagules in turfgrass soil was higher in the margin than in center of patch, where the number of propagules was similar to these of healthy looking soils close to the margin of diseased patch. The meteorological factors influencing the outbreak of the disease were temperature, the number of rainy days and precipitation. Optimum temperature for disease development of Rhizoctonia blight in field was 20~22$^{\circ}C$, and that for hyphal growth of R. solani AG2-2 in vitro was 25~3$0^{\circ}C$. In Pusan area, Rhizoctonia blight first occurred in late April and rapidly developed in late June. The disease slightly decreased during July to August and developed again in late September in 1993. The monthly disease progress in Pusan area was similar to that in Kyeonggi province.

• Parasites, Hosts and Diseases
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• v.42 no.3
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• pp.93-119
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• 2004

Acanthamoeba and Naegleria are widely distributed in fresh water, soil and dust throughout the world, and cause meningoencephalitis or keratoconjunctivitis in humans and other mammals. Korean isolates, namely, Naegleria sp. YM-1 and Acanthamoeba sp. YM-2, YM-3, YM-4, YM-5, YM-6 and YM-7, were collected from sewage, water puddles, a storage reservoir, the gills of a fresh water fish, and by corneal washing. These isolates were categorized into three groups based on the mortalities of infected mice namely, highly virulent (YM-4), moderately virulent (YM-2, YM-5 and YM-7) and nonpathogenic (YM-3). In addition, a new species of Acanthamoeba was isolated from a freshwater fish in Korea and tentatively named Korean isolate YM-4. The morphologic characters of its cysts were similar to those of A. culbertsoni and A. royreba, which were previously designated as Acanthamoeba group III. Based on experimentally infected mouse mortality, Acanthamoeba YM-4 was highly virulent. The isoenzymes profile of Acanthamoeba YM-4 was similar to that of A. royreba. Moreover, an anti-Acanthamoeba YM-4 monoclonal anti-body reacted only with Acanthamoeba YM-4, and not with A. culbertsoni. Random amplified polymorphic DNA marker analysis and RFLP analysis of mitochondrial DNA and of a 188 small subunit ribosomal RNA, placed Acanthamoeba YM-4 in a separate cluster based on phylogenic distances. Thus Acanthamoeba YM-4 was identified as a new species, and assigned Acanthamoeba sohi. Up to the year 2002 in Korea, two clinical cases were found to be infected with Acanthamoeba spp. These patients died of meningoencephalitis. In addition, one case of Acanthamoeba pneumonia with an immunodeficient status was reported and Acanthamoeba was detected in several cases of chronic relapsing corneal ulcer, chronic conjunctivitis, and keratitis.

• Parasites, Hosts and Diseases
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• v.45 no.2 s.142
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• pp.87-94
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• 2007

In this study, we describe Korean isolates of Trichomonas vaginalis infected with double-stranded (ds) RNA virus (TVV). One T. vaginalis isolate infected with TVV IH-2 evidenced weak pathogenicity in the mouse assay coupled with the persistent presence of a dsRNA, thereby indicating a hypovirulence effect of dsRNA in T. vaginalis. Cloning and sequence analysis results revealed that the genomic dsRNA of TVV IH-2 was 4,647 bp in length and evidenced a sequence identity of 80% with the previously-described TVV 1-1 and 1-5, but only a 42% identity with TVV 2-1 and 3 isolates. It harbored 2 overlapping open reading frames of the putative capsid protein and dsRNA-dependent RNA polymerase (RdRp). As previously observed in the TVV isolates 1-1 and 1-5, a conserved ribosomal slip-page heptamer (CCUUUUU) and its surrounding sequence context within the consensus 14-nt overlap implied the gene expression of a capsid protein-RdRp fusion protein, occurring as the result of a potential ribosomal frameshift event. The phylogenetic analysis of RdRp showed that the Korean TVV If-2 isolate formed a compact group with TVV 1-1 and 1-5 isolates, which was divergent from TVV 2-1, 3 and other viral isolates classified as members of the Giardiavirus genus.

• Journal of fish pathology
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• v.26 no.3
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• pp.207-217
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• 2013

Recently high mortality of cultured olive flounder, Paralichthys olivaceus occurred frequently at the fish farms in Ulsan, Korea. The diseased fish showed skinny body and swimming behavior around the water surface with liver atrophy and white enteritis as internal signs. The isolated bacteria were identified to V. scophthalmi by biochemical test, nucleotide analysis of 16S rRNA and dnaJ gene sequencing. The pathogen of this study showed strong pathogenicity as 75% mortality to olive flounder by intraperitoneal injection of $1{\times}10^6$ CFU/fish. The pathological sign was not different between the naturally diseased fish and the artificially infected fish. Histopathological changes were shown to liver atrophy, desquamation of the intestinal mucosa and hyaline droplet like as other previous studies.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.28 no.1
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• pp.99-115
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• 2002

Tests of stability and toxicity, and clinical evaluation of anti-acne activity suggest that cryptotanshinone, a constituent of the roots of Salvia miltiorrhiza Bunge, is an effective active ingredient for acne vulgaris treatments. Acne vulgaris, called acne or pimples, is the most common disease of the pilosebaceous follicle unit of the skin. It affects nearly 80% of people between the ages of 11 and 30. Approximately 30% of teenagers have acne of sufficient severity to require medical treatment. Acne is a follicular disorder of the skin. It occurs in specialized pilosebaceous units on the face and body. Acne develops when these specialized follicles undergo pathologic alterations that result in the formation of non-inflammatory lesions (comedones) and inflammatory lesions (papules, pustules and nodules). An abnormality of keratinizing epithelium of these follicles, thought to be due to the action of sebum synthesized and secreted by the androgen-sensitive sebaceous glands, leads to inflammation induced by the follicular bacterium Propionibacterium acnes. Therapy involves treatments that modify these pathogenic factors and includes drugs with antikeratinizing, antibacterial and antiseborrheic actions. Acne vulgaris is a very frequent disease, seen primarily in adolescents, involving the sebaceous follicles. Acne vulgaris is characterized by a great variety of clinical inflammatory and non-inflammatory lesions: comedones, papules, pustules, nodules, cysts and scars. Acne vulgaris is a multi-factorial disease. Although its pathogenicity is unclear, extensive studies have shown that hyperseborrhea, superinfection by P. acnes and endocrinologic androgenic changes play a role in the development of acne vulgaris.

• The Plant Pathology Journal
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• v.37 no.5
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• pp.476-488
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• 2021

Xanthomonas campestris pv. campestris (Xcc) is the causal agent of black rot for cruciferous vegetables worldwide, especially for the cole crops such as cabbage and cauliflower. Due to the lack of resistant cabbage cultivars, black rot has brought about considerable yield losses in recent years in China. Understanding of the pathogen features is a key step for disease prevention, however, the pathogen diversity, population structure, and virulence are largely unknown. In this study, we studied 50 Xcc strains including 39 Xcc isolates collected from cabbage in 20 regions across China, using multilocus sequence genotyping (MLST), repetitive DNA sequence-based PCR (rep-PCR), and pathogenicity tests. For MLST analysis, a total of 12 allelic profiles (AP) were generated, among which the largest AP was AP1 containing 32 strains. Further cluster analysis of rep-PCR divided all strains into 14 DNA groups, with the largest group DNA I comprising of 34 strains, most of which also belonged to AP1. Inoculation tests showed that the representative Xcc strains collected from diverse regions performed differential virulence against three brassica hosts compared with races 1 and 4. Interestingly, these results indicated that AP1/DNA I was not only the main pathotype in China, but also a novel group that differed from the previously reported type races in both genotype and virulence. To our knowledge, this is the first extensive genetic diversity survey for Xcc strains in China, which provides evidence for cabbage resistance breeding and opens the gate for further cabbage-Xcc interaction studies.

• The Plant Pathology Journal
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• v.35 no.4
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• pp.287-300
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• 2019

Spot blotch caused by Bipolaris sorokiniana has spread to more than 9 million ha of wheat in the warm, humid areas of the Eastern Gangetic Plains (EGP) of South Asia and is a disease of major concern in other similar wheat growing regions worldwide. Differential lignin content in resistant and susceptible genotypes and its association with free radicals such as hydrogen peroxide ($H_2O_2$), superoxide ($O_2{^-}$) and hydroxyl radical ($OH^-$) were studied after inoculation under field conditions for two consecutive years. $H_2O_2$ significantly influenced lignin content in flag leaves, whereas there was a negative correlation among lignin and $H_2O_2$ to the Area Under Disease Progress Curve (AUDPC). The production of $H_2O_2$ was higher in the resistant genotypes than susceptible ones. The $O_2{^-}$ and $OH^-$ positively correlated with AUDPC but negatively with lignin content. This study illustrates that $H_2O_2$ has a vital role in prompting lignification and thereby resistance to spot blotch in wheat. We used cluster analysis to separate the resistant and susceptible genotypes by phenotypic and biochemical traits. $H_2O_2$ associated lignin production significantly reduced the number of appressoria and penetration pegs. We visualized the effect of lignin in disease resistance using differential histochemical staining of tissue from resistant and susceptible genotypes, which shows the variable accumulation of hydrogen peroxide and lignin around penetration sites.

• Microbiology and Biotechnology Letters
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• v.47 no.2
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• pp.310-316
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• 2019

Distribution of Salmonella enterica serovars and their associated virulence determinants is wide-spread among food animals, which are continuously implicated in periodic salmonellosis outbreaks globally. The aim of this study was to determine and evaluate the diversity of five Salmonella serovar virulence genes (invA, pefA, cdtB, spvC and iroN) isolated from food animals and humans. Using standard microbiological techniques, Salmonella spp. were isolated from the feces of humans and three major food animals. Virulence determinants of the isolates were assayed using PCR. Clonal relatedness of the dominant serovar was determined via pulsed-field gel electrophoresis (PFGE) using the restriction enzyme, Xbal. Seventy one Salmonella spp. were isolated and serotyped into 44 serovars. Non-typhoidal Salmonella (NTS; 68) accounted for majority (95.8%) of the Salmonella serovars. Isolates from chicken (34) accounted for 47.9% of all isolates, out of which S. Budapest (14) was predominant (34.8%). However, the dominant S. Budapest serovars showed no genetic relatedness. The invA gene located on SPI-1 was detected in all isolates. Furthermore, 94% of the isolates from sheep harbored the spvC genes. The iroN gene was present in 50%, 100%, 88%, and 91% of isolates from human, chicken, sheep, and cattle, respectively. The pefA gene was detected in 18 isolates from chicken and a single isolate from sheep. Notably, having diverse Salmonella serovars containing plasmid encoded virulence genes circulating the food chain is of public health significance; hence, surveillance is required.