• Journal of Dairy Science and Biotechnology
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• v.38 no.2
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• pp.99-111
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• 2020

Probiotics are actively being studied for their efficacious anticancer, anticholesterol, and antidiabetic properties. As novel probiotic strains are being developed continuously, new strain-specific safety issues may be reported. Therefore, a procedure for the safety evaluation of probiotic strains is needed. In this study, we investigated the current status of domestic and foreign guidelines for the evaluation of safety of probiotics and suggested a general probiotic safety evaluation process. In other countries, the guidelines for probiotic evaluation are provided and managed separately. However, in Korea, general guidelines are provided regarding the use of functional ingredients, and specific guidelines for the use of probiotics are lacking. A review step based on the characteristics of the probiotics has been introduced in the procedure for safety evaluation of probiotics. Additionally, it has been suggested that the safety evaluation process should consider the results of the functional and genomic analysis for strain identification. Moreover, the factors to be evaluated are presented separately for the notified and non-notified strains. The suggested evaluation procedure may ensure the safety of probiotics, thereby promoting enhanced utilization of probiotics as functional products.

• Natural Product Sciences
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• v.15 no.2
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• pp.60-65
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• 2009

Berberis is an important medicinal plant, of the family Berberidaceae. Different Berberis species and their parts are very common in herbal drug markets of India and world over as an adulterant/substitute to 'Daruharidra' i.e. B. aristata DC. Antimicrobial activity of 50% hydroalcoholic extracts of stem of four Berberis species viz. B. aristata DC., B. asiatica Roxb. ex DC., B. chitria Lindl. and B. lycium Royle and the isolated alkaloid berberine were tested against eleven bacterial and eight fungal strains. The extracts with the strongest antibacterial activity was obtained from B. lycium followed by B. aristata, B. asiatica and B. chitria. Based on these results it is possible to conclude that the hydroalcoholic extract and alkaloid (berberine) has stronger and broader spectrum against bacterial strains as compared to fungal strains. The result obtained in the present study authenticates and support the use of these plants in folklore medicine for treatment of various infectious diseases caused by the bacterial pathogens. However, an attempt has been made to explore the possibilities of utilizing stem part rather than roots of these species with the aim to conserve this species which is over exploited due to diverse use of its root. These findings will stimulate the search for novel, natural products as new antibacterial/antifungal agents which may be useful to pharmaceutical industries.

• The Plant Pathology Journal
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• v.30 no.3
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• pp.316-322
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• 2014

Recently, a Cucumber mosaic virus (CMV) strain, named as CMV-209, was isolated from Glycine soja. In this study, symptom expression of CMV-209 was analyzed in detail in Nicotiana benthamiana by comparing with that of CMV-Fny, which is a representative strain of CMV. Using infectious cDNA clones of CMV strains 209 and Fny, symptom expression of various pseudorecombinants between these two strains were examined in the early and late infection stages. In the early infection stage, the pseudorecombinants containing Fny-RNA2 induced stunting and leaf distortion on the newly emerged leaves whereas the pseudorecombinants containing 209-RNA2 caused no obvious symptoms. In the late infection stage, the pseudorecombinants containing 209-RNA1 and Fny-RNA2 induced severe leaf distortion and stunting, while CMV-209 induced mild symptom and CMV-Fny caused typical mosaic, general stunting, and leaf distortion symptoms, indicating that RNA 2 encodes a symptom determinant(s) of CMV, which is capable of enhancing symptoms. Furthermore, our results support the possibility that natural recombination between compatible viruses can result in emergence of novel viruses causing severe damages in crop fields.

• Korean Journal of Microbiology
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• v.40 no.4
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• pp.302-306
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• 2004

A total of forty strains of pigment-producing halophilic bacteria were isolated from the solar saltern and coastal seawater in Korea. The diversity of those bacteria were determined on the basis of PCR-RFLP and 16S rDNA sequences. The isolated strains were clssified into nine genera: Pseudoalteromonas, Photobacterium, Vibrio, Halobacillus, Bacillus, Paracoccus, Salinicoccus, Tenacilbaculum, and Flavobacterium. While more than $80\%$ of the pigment-producing halophilic bacteria isolated from the coastal seawater were classified as gram-negative Pseudolateromonas, most of the strains isolated from the solar saltern were classified into gram-positive Halo­bacillus. The other strain was KK7, which may be identified as novel species belonging to the genus, Salini­coccus.

• The Korean Journal of Mycology
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• v.46 no.1
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• pp.22-27
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• 2018

We isolated endophytic fungal strains from the leaves of Abies koreana growing in Korea. The fungal strains were identified as Coleophoma parafusiformis and Coniochaeta ligniaria, based on morphological characteristics and sequence analysis of the internal transcribed spacer region and large subunit region of ribosomal DNA. These species have not been previously reported in Korea. In this study, we report the morphological characteristics and results of phylogenetic analysis of the two novel fungal strains.

• YAKHAK HOEJI
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• v.41 no.4
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• pp.462-472
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• 1997

In this approach, the antimicrobial activities of the compounds were compared with the ${\beta}$-lactam antibiotics against ${\beta}$-lactamase producing strains in vitro. Heteroc yclyl exomethylenepenam derivatives were several numbers of 6-exomethylenepenam sodiums (CH1240, CH1245, CH1250, CH2140, CH2145, CH2150). The inhibitory concentraion assay of six compounds were compared with clavulanic acid, sulbactam, tazobactam. Clavulanic acid, sulbactam and tazobactam are used as inhibitors of a variety of plasmid-mediated beta-lactamases. In vitro ${\beta}$-lactamase inhibitory assay, CH1240 and CH2140 were more active than clavulanic acid, sulbactam and tazobactam against ${\beta}$-lactamases overally. And in vitro comparative antimicrobial susceptibility test of six inhibitors were performed with mixed forms of ampicillin, cefotaxime, amoxicillin, ticarcillin, piperacillin, cefoperazone against ${\beta}$-lactamase producing 31 species strains. Consequently CH2140 and CH1240 among the six compounds enhanced the activity of the ${\beta}$-lactams for 31 ${\beta}$-lactamase producing strains.

• Journal of Microbiology and Biotechnology
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• v.29 no.10
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• pp.1543-1552
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• 2019

Salmonella is a common zoonotic and foodborne pathogen that causes high morbidity and mortality in developing countries. In this study, we established and validated a polymerase spiral reaction (PSR) assay which targeted the conserved invasion gene (invA) of Salmonella by SYBR Green I indicator methods. Subsequently, assays for determination of the optimal conditions for optimal specificity and sensitivity of PSR were performed. We performed comprehensive evaluations using loop-mediated isothermal amplification (LAMP) and real-time PCR. A total number of 532 samples of daily food were analyzed by PSR. Twenty-seven bacterial strains were tested in the specificity assay, from which positive results were obtained only for 14-Salmonella strains. However, none of the 13 non-Salmonella strains was amplified. Similarly with LAMP and real-time PCR, the detection limit of the PSR assay was 50 CFU/ml. The PSR method was also successfully applied to evaluate the contamination with Salmonella in 532 samples of daily food, corroborating traditional culture method data. The novel PSR method is simple, sensitive, and rapid and provides new insights into the prevention and detection of foodborne diseases.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.6
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• pp.850-857
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• 2022

Seventy-five Vibrio parahaemolyticus isolates from the surface seawater of the Geum River Estuary area, on the west coast of Korea, were analyzed for the presence of virulence genes and susceptibility to 17 different antimicrobials. All 75 isolates were examined for the presence of two virulence genes (tdh or trh) using polymerase chain reaction; Only one of the isolates possessed the tdh or trh gene. According to the results of disk diffusion susceptibility tests, all of the strains were resistant to penicillin G, 92.0% were resistant to ampicillin, 82.7% were resistant to amoxicillin, 2.7% were resistant to ciprofloxacin, 2.7% were resistant to trimethoprim, 1.3% were resistant to cephalothin, and 1.3% were resistant to erythromycin. However, all of the strains were susceptible to amikacin, cefoxitin, chloramphenicol, gentamycin, kanamycin, nalidixic acid, nitrofurantoin, rifampin, streptomycin, and tetracycline. The average minimum inhibitory concentrations for ampicillin for V. parahaemolyticus was 557.6 ㎍/mL. These results not only provide novel insight into the necessity for seawater sanitation in Geum river estuary area, but they help reduce the risk of contamination of antimicrobial-resistant bacteria.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.4
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• pp.520-525
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• 2023

This study aimed to detect Enterococcus spp. strain, a fecal contamination indicator, by PCR assay from short neck clams Venerupis philippinarum in Cheonsu Bay area, Chu Island area and Wonsan Island area, the west coast of Korea, from November 2022 to February 2023 of Enterococcus spp. strain was detected in 19 (79.2%) among 24 samples, and its concentration ranged from <18 to 33,000 MPN (most probable number)/100 g. The 269 isolated Enterococcus spp. strains were identified by PCR assay, and Enterococcus spp. distribution in short neck clams were E. faecium (39.8%), E. faecalis (23.0%), E. hirae (21.9%), E. gallinarum (10.4%), E. casseliflavus (1.5%), E. durans (1.5%) and unidentified strains (1.9%). Thus, E. faecium was the most dominant strain followed by E. faecalis. Overall, these results provide novel insight into the necessity for shellfish sanitation in the sea and could help reduce the fecal contamination risk.

• Journal of Veterinary Science
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• v.21 no.5
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• pp.71.1-71.10
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• 2020

Background: Feline calicivirus (FCV) is a major and highly infectious pathogen in cats worldwide. However, there have been limited studies about the status of FCV infections in Korea. Objectives: To investigate the current status of FCV infections in stray cats in Korea. Methods: A novel reverse transcription polymerase chain reaction (RT-PCR) assay was developed based on the conserved nucleotide sequences of reported FCV strains. Field swab samples were collected from 122 cats (2 hospital admitted cats and 120 stray cats) in 2016 and 2017. All the samples were tested by virus isolation and 2 different RT-PCRs, including the novel RT-PCR, for the detection of FCV. Results: The novel RT-PCR assay showed no cross-reactivity to the nucleic acids of the other feline pathogens tested, and the limit of detection was calculated as 10⁰ TCID₅₀/mL based on an in vitro assessment. The novel RT-PCR assay detected 5 positive samples from the 122 field samples, which showed perfect agreement with the results of the virus isolation method. In contrast, another RT-PCR assay used in a previous study in Korea detected no positive samples. The prevalence of FCV infection in stray cats was 2.5% (3/120) based on the results of virus isolation and the novel RT-PCR assays. Conclusions: The current study is the first report of the detection and prevalence of FCV in stray cats in Korea. The novel RT-PCR assay developed in this study showed high sensitivity and specificity, which indicates a useful diagnostic assay to identify FCV infection in cats.