• Korean Journal of Microbiology
• /
• v.53 no.4
• /
• pp.323-325
• /
• 2017

Pectobacterium carotovorum subsp. actinidiae KKH3 is an Enterobacteriaceae bacterial pathogen that infects kiwi plants, causing canker-like symptoms that pose a threat to the kiwifruit industry. Because the strain was originally isolated from woody plants and possesses numerous plant cell wall-degrading enzymes, this draft genome report provides insight into possible bioconversion applications, as well as a better understanding of this important plant pathogen.

• The Plant Pathology Journal
• /
• v.35 no.1
• /
• pp.1-10
• /
• 2019

Wheat blast occurred in Bangladesh for the first time in Asia in 2016. It is caused by a fungal pathogen, Magnaporthe oryzae Triticum (MoT) pathotype. In this review, we focused on the current status of the wheat blast in regard to host, pathogen, and environment. Despite the many efforts to control the disease, it expanded to neighboring regions including India, the world's second largest wheat producer. However, the disease occurrence has definitely decreased in quantity, because of many farmers chose to grow alternate crops according to the government's directions. Bangladesh government planned to introduce blast resistant cultivars but knowledges about genetics of resistance is limited. The genome analyses of the pathogen population revealed that the isolates caused wheat blast in Bangladesh are genetically close to a South American lineage of Magnaporthe oryzae. Understanding the genomes of virulent strains would be important to find target resistance genes for wheat breeding. Although the drier winter weather in Bangladesh was not favorable for development of wheat blast before, recent global warming and climate change are posing an increasing risk of disease development. Bangladesh outbreak in 2016 was likely to be facilitated by an extraordinary warm and humid weather in the affected districts before the harvest season. Coordinated international collaboration and steady financial supports are needed to mitigate the fearsome wheat blast in South Asia before it becomes a catastrophe.

• The Plant Pathology Journal
• /
• v.35 no.5
• /
• pp.530-537
• /
• 2019

Fuji, a major apple cultivar in Korea, is susceptible to white rot. Apple white rot disease appears on the stem and fruit; the development of which deteriorates fruit quality, resulting in decreases in farmers' income. Thus, it is necessary to characterize molecular markers related to apple white rot resistance. In this study, we screened for differentially expressed genes between uninfected apple fruits and those infected with Botryosphaeria dothidea, the fungal pathogen that causes white rot. Antimicrobial tests suggest that a gene expression involved in the synthesis of the substance inhibiting the growth of B. dothidea in apples was induced by pathogen infection. We identified seven transcripts induced by the infection. The seven transcripts were homologous to genes encoding a flavonoid glucosyltransferase, a metallothionein-like protein, a senescence-induced protein, a chitinase, a wound-induced protein, and proteins of unknown function. These genes have functions related to responses to environmental stresses, including pathogen infections. Our results can be useful for the development of molecular markers for early detection of the disease or for use in breeding white rotresistant cultivars.

• Research in Plant Disease
• /
• v.27 no.1
• /
• pp.24-31
• /
• 2021

Since the past few years, dimple rot has become one of the most serious diseases affecting Actinidia chinensis var. chinensis 'Zesy002' kiwifruit in Korea, leading to a low quality and subsequent losses of income. In the current study, the causal pathogen of side rot on 'Zesy002' kiwifruit was identified to be Botryosphaeria dothidea, a widespread pathogen that could penetrate the fruit directly without wounding. Diaporthe sp., another pathogen causing dimple rot, was isolated from infected kiwifruit. It was not able to infect fruits without wounding. Dimple-rot symptoms are known to be associated with other pathogens from the Pseudocercospora genus. In this study, B. dothidea was ratified as the causal disease agent in Jeju Island. To illustrate the pathogenicity of this fungus on 'Zesy002', further studies such as observation of infection structures of fungus may be needed.

• Biomedical Science Letters
• /
• v.28 no.2
• /
• pp.83-91
• /
• 2022

This study was performed to investigate the contamination status of microorganisms that cause food poisoning in shellfish distributed in the metropolitan area of South Korea. The analyses were conducted according to the sample type, season, and region. In particular, the genotype of food poisoning viruses that explosively cause collective food poisoning was analyzed. Total 483 each of four types of shellfish (Crassostrea gigas, Mytilus coruscus, Pectea albicans albicans, and Scapharca subcrenata) were collected from four distribution sites located in the metropolitan area. We investigated foodborne pathogen by multiplex PCR and RT/Nested PCR from shellfish. As a result, Vibrio parahaemolyticus and Bacillus cereus were detected in 13 and 21 samples and Norovirus (NoV) GI and GII were detected in 7 and 12 samples, respectively. V. parahaemolyticus and NoV GI and GII showed differences in types of shellfish and seasons, and no correlation was confirmed with regional differences. Also, as a result of genotyping for the detected NoV GI and GII, they were confirmed as NoV GI.7, GI.5 and GII.3, which are causes of collective food poisoning. Therefore, cross-infection with shellfish can cause food poisoning. In particular, attention must be paid to the handling and cooking of shellfish in organizations that implement group feeding, and it is necessary to establish a management system for microorganisms that cause food poisoning in the process of shellfish farming and distribution.

• Mycobiology
• /
• v.50 no.1
• /
• pp.79-85
• /
• 2022

Strawberries are a popular economic crop, and one of the major plantations and exporting countries is Korea in the world. The Fusarium oxysporum species complex (FOSC) is a soil-borne pathogen with genetic diversity, resulting in wilt disease in various crops. In Korea, strawberries wilt disease was first reported in the 1980s due to the infection of FOSC, causing significant economic damage every year. The causal agent, F. oxysporum f. sp. fragariae, is a soil-borne pathogen with a characteristic of FOSC that is difficult to control chemically and mutates easily. This study obtained genetic polymorphism information that was based on AFLP, of F. oxysporum f. sp. fragariae 91 strains, which were isolated from strawberry cultivation sites in Gyeongsangnam-do and Chungcheongnam-do, and compared strains information, which was the isolated location, host variety, response to chemical fungicide, and antagonistic bacteria, and mycelium phenotype. As a result, AFLP phylogeny found that two groups were mainly present, and group B was present at a high frequency in Gyeongsangnam-do. Group B proved less sensitive to tebuconazole than group A through Student's t-test. In addition, the fractions pattern of AFLP was calculated by comparing the strain information using PCA and PERMANOVA, and the main criteria were separated localization and strawberry varieties (PERMANOVA; p< 0.05). And tebuconazole was different with weak confidence (PERMANOVA; p< 0.10). This study suggests that the F. oxysporum f. sp. fragariae should be continuously monitored and managed, including group B, which is less chemically effective.

• Genomics & Informatics
• /
• v.20 no.4
• /
• pp.41.1-41.9
• /
• 2022

The pathogen Gallibacterium anatis has caused heavy economic losses for commercial poultry farms around the world. However, despite its importance, the functions of its hypothetical proteins (HPs) have been poorly characterized. The present study analyzed the functions and structures of HPs obtained from Gallibacterium anatis (NCTC11413) using various bioinformatics tools. Initially, all the functions of HPs were predicted using the VICMpred tool, and the physicochemical properties of the identified virulence proteins were then analyzed using Expasy's ProtParam server. A virulence protein (WP_013745346.1) that can act as a potential drug target was further analyzed for its secondary structure, followed by homology modeling and three-dimensional (3D) structure determination using the Swiss-Model and Phyre2 servers. The quality assessment and validation of the 3D model were conducted using ERRAT, Verify3D, and PROCHECK programs. The functional and phylogenetic analysis was conducted using ProFunc, STRING, KEGG servers, and MEGA software. The bioinformatics analysis revealed 201 HPs related to cellular processes (n = 119), metabolism (n = 61), virulence (n = 11), and information/storage molecules (n = 10). Among the virulence proteins, three were detected as drug targets and six as vaccine targets. The characterized virulence protein WP_013745346.1 is proven to be stable, a drug target, and an enzyme related to the citrate cycle in the present pathogen. This enzyme was also found to facilitate other metabolic pathways, the biosynthesis of secondary metabolites, and the biosynthesis of amino acids.

• The Plant Pathology Journal
• /
• v.39 no.6
• /
• pp.584-591
• /
• 2023

Active plant immune response involving programmed cell death called the hypersensitive response (HR) is elicited by microbial effectors delivered through the type III secretion system (T3SS). The marine bacterium Hahella chejuensis contains two T3SSs that are similar to those of animal pathogens, but it was able to elicit HR-like cell death in the land plant Nicotiana benthamiana. The cell death was comparable with the transcriptional patterns of H. chejuensis T3SS-1 genes, was mediated by SGT1, a general regulator of plant resistance, and was suppressed by AvrPto1, a type III-secreted effector of a plant pathogen that inhibits HR. Thus, type III-secreted effectors of a marine bacterium are capable of inducing the nonhost HR in a land plant it has never encountered before. This suggests that plants may have evolved to cope with a potential threat posed by alien pathogen effectors. Our work documents an exceptional case of nonhost HR and provides an expanded perspective for studying plant nonhost resistance.

• International Journal of Oral Biology
• /
• v.49 no.3
• /
• pp.79-86
• /
• 2024

Periodontal disease (PD) is strongly linked to increased risk of oral squamous cell carcinoma (OSCC); however, the specific mechanism through which the development of PD and OSCC is simultaneously promoted remains unclear. This study explored the impact of periodontal pathogens on OSCC progression and the contribution of periodontal pathogen-stimulated OSCC to PD development. The expression of osteoclastogenesis-inducing factors was assessed using quantitative reverse transcription polymerase chain reaction analysis following stimulation of OSCC with lipopolysaccharide (LPS) derived from the periodontal pathogen Porphyromonas gingivalis (Pg), a pathogen commonly responsible for PD. The cell counting kit-8 assay was used to determine the effects of Pg-LPS on OSCC proliferation and drug resistance to cisplatin and 5-fluorouracil. The effects of conditioned medium (CM) derived from Pg-LPS-stimulated OSCC on osteoclastogenesis was evaluated using tartrate-resistant acid phosphatase (TRAP) staining on bone marrow-derived macrophages (BMMs). Pg-LPS administration in SCC-25 and YD-8 OSCC cell lines induced a significant increase in receptor activator of nuclear factor kappa-B ligand mRNA expression; however, it did not affect cell proliferation. Treatment with CM derived from Pg-LPS-stimulated SCC-25 or YD-8 cells markedly enhanced the formation of TRAP-positive multinucleated cells during osteoclast differentiation of BMMs. Altogether, these findings demonstrate that Pg-LPS-stimulated OSCC promoted osteoclastogenesis through a paracrine mechanism.

• Research in Plant Disease
• /
• v.16 no.3
• /
• pp.266-273
• /
• 2010

Bacterial pustule of soybean (Glycines max) caused by Xanthomonas axonopodis pv. glycines is one of the most prevalent bacterial diseases of soybean. This bacterium shows strong pathogenicity to the plants and distributes throughout Korea. However, no good control measures including bactericides and resistant cultivars are available to control the disease in Korea. Therefore, this study was conducted to develop chemical control method against soybean bacterial pustule. The present study was undertaken to find out the growth inhibitory effect bactericides (8 antibiotics, 2 copper compounds, quinoline, 18 agro-chemicals) on bacterial pustule pathogen. Antibiotics test showed that tetracycline and streptomycin sulfate significantly suppressed the growth of bacterial pustule pathogen. Also, application of oxolinic acid was found to be effective for pathogen inhibition. However, vancomycin, polymyxin B sulfate and copper compounds did not show the positive suppressive effect on growth of the pathogen. Among the eighteen agro-chemicals, streptomycin sulfate + oxytetracyclin (18.8 + 1.5%) WP, oxytetracycline (17%) WP and oxolinic acid (20%) WP were found to be effective for the inhibition of the pathogen in vitro. The selected 5 agro-chemicals were also applied on soybean in field and their control effects against the soybean bacterial pustule were tested. The foliar application of streptomycin sulfate + oytetracyclin WP and oxytetracycline WP on the naturally infected soybean (Taekwangkong) showed high control value (above 70%). Therefore, it is concluded that the bactericides used in this study showed strong inhibitory effect to soybean bacterial pustule and they can be recommend to farmers to control the disease.