• Journal of Microbiology and Biotechnology
• /
• v.32 no.12
• /
• pp.1605-1614
• /
• 2022

The strains associated with foodborne Salmonella enterica Thompson outbreaks in Korea have not been identified. Therefore, we characterized S. Thompson strains isolated from chocolate cakes linked to foodborne outbreaks in Korea. A total of 56 strains were isolated from preserved cake products, products in the supply chain distribution, the manufacturer's apparatus, and egg white liquid products used for cream preparation. Subsequently, serological typing, pathogenic gene-targeted polymerase chain reaction (PCR), pulsed-field gel electrophoresis (PFGE), and whole-genome multi-locus sequence typing (wgMLST) were performed to characterize these isolates. The antigen formula of all isolates was 7:k:1,5, namely Salmonella enterica subsp. enterica Serovar Thompson. All 56 isolates harbored invA, his, hin, and stn, and were negative for sefA and spvC based on gene-targeted PCR analyses. Based on PFGE results, these isolates were classified into one group based on the same SP6X01.011 pattern with 100% similarity. We selected 19 strains based on the region and sample type, which were subjected to wgMLST. Although the examined strains showed 100% similarity, they were classified into seven clusters based on allelic differences. According to our findings, the cause of these outbreaks was chocolate cake manufactured with egg white liquid contaminated with the same Salmonella Thompson. Additionally, comparative analysis of wgMLST on domestic isolates of S. Thompson from the three outbreaks showed genetic similarities of over 99.6%. Based on the results, the PFGE and wgMLST combination can provide highly resolved phylogeny and reliable evidence during Salmonella outbreak investigations.

• Mycobiology
• /
• v.50 no.5
• /
• pp.302-316
• /
• 2022

Many Apiospora species have been isolated from bamboo plants - to date, 34 bambusicolous Apiospora species have been recorded. They are known as saprophytes, endophytes, and plant pathogens. In this study, 242 bambusicolous Apiospora were isolated from various bamboo materials (branches, culms, leaves, roots, and shoots) and examined using DNA sequence similarity based on the internal transcribed spacer, 28S large subunit ribosomal RNA gene, translation elongation factor 1-alpha, and beta-tubulin regions. Nine Apiospora species (Ap. arundinis, Ap. camelliae-sinensis, Ap. hysterina, Ap. lageniformis sp. nov., Ap. paraphaeosperma, Ap. pseudohyphopodii sp. nov., Ap. rasikravindrae, Ap. saccharicola, and Ap. sargassi) were identified via molecular analysis. Moreover, the highest diversity of Apiospora was found in culms, and the most abundant species was Ap. arundinis. Among the nine Apiospora species, two (Ap. hysterina and Ap. paraphaeosperma) were unrecorded in Korea, and the other two species (Ap. lageniformis sp. nov. and Ap. pseudohyphopodii sp. nov.) were potentially novel species. Here, we describe the diversity of bambusicolous Apiospora species in bamboo organs, construct a multi-locus phylogenetic tree, and delineate morphological features of new bambusicolous Apiospora in Korea.

• Mycobiology
• /
• v.45 no.4
• /
• pp.401-408
• /
• 2017

Colletotrichum gloeosporioides is an economically important fungal pathogen causing substantial yield losses indifferent host plants. To understand the genetic diversity and molecular epidemiology of this fungus, we have developed a novel, high-resolution multi-locus microsatellite typing (MLMT) method. Bioinformatic analysis of C. gloeosporioides unannotated genome sequence yielded eight potential microsatellite loci, of which five, CG1 $(GT)_n$, CG2 $(GT1)_n$, CG3 $(TC)_n$, CG4 $(CT)_n$, and CG5 $(CT1)_n$ were selected for further study based on their universal amplification potential, reproducibility, and repeat number polymorphism. The selected microsatellites were used to analyze 31 strains of C. gloeosporioides isolated from 20 different host plants from India. All microsatellite loci were found to be polymorphic, and the approximate fragment sizes of microsatellite loci CG1, CG2, CG3, CG4, and CG5 were in ranges of 213-241, 197-227, 231-265, 209-275, and 132-188, respectively. Among the 31 isolates, 55 different genotypes were identified. The Simpson's index of diversity (D) values for the individual locus ranged from 0.79 to 0.92, with the D value of all combined five microsatellite loci being 0.99. Microsatellite data analysis revealed that isolates from Ocimum sanctum, Capsicum annuum (chili pepper), and Mangifera indica (mango) formed distinct clusters, therefore exhibited some level of correlation between certain genotypes and host. The developed MLMT method would be a powerful tool for studying the genetic diversity and any possible genotype-host correlation in C. gloeosporioides.

• Korean Journal of Clinical Laboratory Science
• /
• v.50 no.3
• /
• pp.331-336
• /
• 2018

In this study, multi-locus sequence typing (MLST) analysis of 40 clinically isolated Candida albicans in tertiary hospitals in Daejeon, Korea, confirmed the nucleotide sequence and phylogenetic relationships of the strains collected from different specimen sources. The general variations found in seven different housekeeping genes of C. albicans, collected from urine and sputum, peripheral blood, central line blood, and other specimens, were analyzed. The phylogenetic tree was divided into 18 sub-clusters (1), a central line blood (2), others (5), sputum (1), peripheral blood (6), sputum (1), and urine (1), and the isolates at the same site were confirmed to have genetic similarity. Consequently, genetic similarity and the potential relevance were found in the strains collected from the same specimen sources. MLST analysis of C. albicans suggests that persistent data accumulation of phylogenetic gene variations of C. albicans may help establish infectious disease studies and epidemiological surveillance systems.

• Biomedical Science Letters
• /
• v.24 no.3
• /
• pp.221-229
• /
• 2018

Trichophyton rubrum is one of the well-known pathogenic fungi and causes dermatophytosis and cutaneous mycosis in human world widely. However, there are not an available sequence type (ST) classification methods and previous studies for T. rubrum until now. Therefore, currently, molecular biological tools using their DNA sequences are used for genotype identification and classification. In the present study, in order to characterize the genetic diversity and the phylogenetic relation of T. rubrum clinical isolates, five different housekeeping genes, such as actin (ACT), calmodulin (CAL), RNA polymerase II (RPB2), superoxide dismutase 2 (SOD2), and ${\beta}$-tubulin (BT2) were analyzed using by multilocus sequence typing (MLST). Also, DNA sequence analysis was performed to examine the differences between the sequences of Trichophyton strains and the identified genetic variations sequence. As a result, most of the sequences were shown to have highly matched rates in their housekeeping genes. However, genetic variations were found on three different positions of ${\beta}$-tubulin gene and were shown to have changed from $C{\rightarrow}G$ (1766), $G{\rightarrow}T$ (1876), and $C{\rightarrow}A$ (1886). To confirm the association with T. rubrum inheritance, a phylogenetic tree analysis was performed. It was classified as four clusters, but there was little significant correlation. Even so, MLST analysis is believed to be helpful for determining the genetic variations of T. rubrum in cases where there is more large-scale data accumulation. In conclusion, the present study demonstrated the first MLST analysis of T. rubrum in Korea and explored the possibility that MLST could be a useful tool for studying the epidemiology and evolution of T. rubrum through further studies.

• Tuberculosis and Respiratory Diseases
• /
• v.76 no.1
• /
• pp.30-33
• /
• 2014

We report the first Korean case of lung diseases caused by Mycobacterium abscessus subsp. bolletii in a previously healthy male, except for a previous history of pulmonary tuberculosis and bronchiectasis. All serial isolates are identified as M. abscessus subsp. bolletii by multi-locus sequence analysis based on the hsp65, rpoB, and 16S rRNA fragments. At the genetic level, the isolate has the erm(41) gene with a T28 sequevar, associated with clarithromycin resistance, and no rrl mutation. The isolate is resistant to clarithromycin. Although the symptoms and radiographic findings have improved after combination of antibiotics, the follow-up sputum cultures are persistently positive.

• The Korean Journal of Mycology
• /
• v.51 no.3
• /
• pp.239-243
• /
• 2023

The Golovinomyces biocellatus complex is known to consist of powdery mildew from the Golovinomyces genus, associated with host plants from the Lamiaceae family. Recent molecular phylogenetic analyses have resolved the taxonomic composition of this complex, and Golovinomyces biocellatus sensu stricto is considered to be a pathogen of Glechoma species, globally. However, this paper presents a new finding of Golovinomyces salviae on Glechoma longituba, besides its original host species of Salvia. This information was inferred by molecular phylogenetic analyses from the multi-locus nucleotide sequence dataset of intergeneric spacer (IGS), internal transcribed spacer (ITS), large subunit (LSU) of rDNA, and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene. Further, the asexual morphology of this fungus is described and illustrated.

• The Korean Journal of Mycology
• /
• v.50 no.3
• /
• pp.195-204
• /
• 2022

A fungal strain, designated KNUF-20-NI009, was isolated from soil collected from Gunsan-si, Jeollabuk-do, Korea. The isolate showed cultural features typical of the genus Xenoroussoella. Colonies cultivated on malt extract agar were olivaceous-brown to pale olivaceous-white at the margins, with undersides of dark olivaceous to olivaceous-brown and a white margin. The conidia, with a size range of 2.7-5.1×1.6-3.3 ㎛ ($\bar{x}=3.6\times2.6{\mu}m$, n=50), were globoid to ellipsoid in shape, hyaline when immature, becoming light brown to golden-brown when mature, and characterized by 1 or 2 guttules. Multi-locus sequence analysis based on a combined dataset of internal transcribed spacer regions (ITS), large subunit rDNA (LSU), small subunit rDNA (SSU), translation elongation factor 1-alpha (TEF1α), and RNA polymerase II largest subunit (RPB2) sequences revealed KNUF-20-NI009 to be a strain of Xenoroussoella triseptata. This is the first report of this species in Korea.

• Research in Plant Disease
• /
• v.29 no.2
• /
• pp.118-129
• /
• 2023

Fusarium sambucinum species complex (FSAMSC) is an important taxonomic group, causing severe plant diseases. Many studies were carried out on FSAMSC plant diseases in Korea, but only 2 species (F. graminearum, F. sambucinum) from 14 host plants were registered in the List of Plant Disease in Korea. To clarify FSAMSC diversity and their pathogenecity, we examined FSAMSC isolates preserved in the Korean Agricultural Culture Collection. Fifty-seven strains were reidentifed as 7 species (F. asiaticum, F. graminearum, F. vorosii, F. meridionale, F. boothii, F. kyushuense, F. armeniacum) based on multi-locus sequence typing analysis. According to previous reports and result of this study, 5 species (F. asiaticum, F. graminearum, F. vorosii, F. armeniacum, F. sambucinum) were pathogenic on 24 host plants in FSAMSC, while the pathogenicity of 3 species (F. meridionale, F. boothii, F. kyushuense) were not clear.

• The Korean Journal of Mycology
• /
• v.46 no.4
• /
• pp.375-382
• /
• 2018

Members of the genus Mortierella (Mortierellales) are filamentous fungi, which are found on nearly all substrates, but more frequently in soil. Till date, 7 species of Mortierella have been reported in Korea, but being a ubiquitous group with high species diversity in temperate zones, this number is still low. During a survey of fungal biodiversity in Korea, we collected many isolates of Mortierella, and through morphological and molecular phylogenetic analyses, identified them to be 3 previously unrecorded species, namely, M. chienii, M. epicladia, and M. gamsii. A total of 10 Mortierella species in Korea, including the 3 species reported in the present study, are widely distributed in 5 out of 7 phylogenetic groups of this genus. This indicates that the diversity of Mortierella was so far underestimated in Korea. Multi-locus sequence analysis is required to provide a more reliable backbone for some uncertain phylogenetic groupings and to more clearly define a species of Mortierella, which would encourage deeper research in the diversity and ecological roles of Mortierella and allied genera.