• Plant Disease and Agriculture
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• v.5 no.2
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• pp.100-104
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• 1999

A total of 65 isolates of Penicillium were isolated from decayed post-harvest fruits of apple pear citrus and grape. The Penicillium species isolated from the apple were idnetified as P. aurantiogriseum and P. expansum those from the pear were P. crustosum and P. expansum and those from the grape were P. aurantiogriseum and P. expansum, From decayed citrus fruits. P. digitatum and P. italicum were isolated. Citrinin and patulin from these species in the YES(yeast extract sucrose) broth were extracted with ethyl acetate and purified by thin-layer chromatography(TLC) and high performance liquid chromatography(HPLC) Among 51 isolates of Penicillium from apple pear and grape 7 isolates produced citrinin 13 isolates produces patulin and 12 isolates produced citrinin and patulin also. All 14 isolates of Penicillium from citrus produced only patulin.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.116.2-117
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• 2003

Late blight, caused by Phytophthora infestans, is one of the most destructive disease on potato and tomato cultivation. To analysis genetic diversity P. infeatans isolates were collected from potato and tomato fields in Korea. These pathogens contained both Al and A2 mating type with metalaxyl-resistant and sensitive isolates. Polymorphisms showed base on RAPD (Random Amplified Polymorphic DNA) in both potato and tomato isolates of P. infestans. Cluster analysis showed high level genetic variation in potato isolates of P. infestans than tomato isolates. P. infestans isolates were observed genetic diversity among them but not grouped among isolates related mating type and metalaxyl response. These results exhibited that P. infestans isolates showing genetic difference among them were distributed in Korea.

• The Korean Journal of Soil Zoology
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• v.9 no.1_2
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• pp.12-15
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• 2004

Five isolates of Belonolaimus longicaudatus collected from different geographical locations and hosts in southeastern United Stated were tested to determine their host specificity and reproductive compatibility. Both the Georgia and Lake Alfred isolates reproduced well on cotton, bermudagrass, and citrus. On the other hand, the North Carolina and Gainesville isolates reproduced poorly on all crops. The Hastings isolate reproduced well on cotton and potato. The Lake Alfred and Hastings isolates showed greater host specificity to their original host of citrus and potato, respectively. Except for the Hastings isolate, all isolates reproduced poorly on potato, which clearly differentiated the Hastings isolate from others (P>0.05). Hybridization test presented reproductive compatibility among five different isolates of B. longicaudatus by generating F$_1$ offspring. The Gainesville males showed comparatively poor ability to fertilize other females and generated a lower number of offspring. In contrast, the North Carolina males were attracted by all the other isolates of sting nematode, and produced the highest number of juveniles.

• Korean Journal of Veterinary Service
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• v.40 no.1
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• pp.41-46
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• 2017

The purpose of this study was to investigated the fluoroquinolone (FQ) resistance and presence of gyrA and grlA gene in 87 Staphylococcus pseudintermedius isolates obtained from clinical samples of dogs and cats. Also, the profiles of FQ resistance compared with methicillin resistant S. pseudintermedius (MRSP) isolates. FQ resistance was observed for enrofloxacin (41.4%), ciprofloxacin (39.1%), norfloxacin (36.8%), ofloxacin and levofloxacin (32.2%, respectively), and moxifloxacin (31.0%). Thirty-eight (43.7%) of 87 S. pseudintermedius isolates were resistant to more than one FQ. Twenty-six (64.5%) of 38 FQ resistant isolates were resistant to all the six FQ tested. Of 38 FQ resistant isolates, gyrA gene was detected in all isolates but grlA gene was not found. Moreover, 19 MRSP isolates were resistant to enrofloxacin (63.2%), ciprofloxacin (57.9%), norfloxacin (52.6%), and ofloxacin, levofloxacin and moxifloxacin (47.4%, respectively). FQ resistance were highly prevalence in S. pseudintermedius isolates from dogs and cats. Our results emphasize the prudent use of antimicrobial agents to companion animals is necessary for prevent antimicrobial resistance.

• Journal of the Korean Wood Science and Technology
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• v.33 no.2 s.130
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• pp.56-64
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• 2005

This study was performed to investigate the frequency of blue staining fungal species collected from pine trees, Experimental Forests of Kangwon National University in Korea based on their morphological characteristics. In addition the tolerance to fungicide, Woodguard, was assessed to get basic knowledges for preventing blue stain of wood. Totally Leptographium-type fungi were dominated by 79.3% among Ophiostomatoid fungi associated with scolityd bark beetles in pine trees. Leptographium-type Ds-isolates which have unusual morphology were collected as frequency of 17.0%. The most distinct differeneces of these Ds-isolates from L. procerum were the presence of roughened hyphae and flask-shaped conidiophores that have never been mentioned formerly for L. procerum, but since these Ds-isolates formed black concentric rings being a property of L. procerum, the Df-isolates were characterized as Leptographium-type fungi, which are the most common species with the highest frequency by 33.2% in this particular area. According to our experimental results, Leptographium-type Ds- and Df-isolates were very resistant to fungicide, Woodguard, therefore it was suggested that a new method for wood protection from the blue staining fungi should be developed. Exact identification of blue staining isolates collected from pine trees is keep going.

• Biomedical Science Letters
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• v.25 no.4
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• pp.321-330
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• 2019

Carbapenem is recently considered as the last resort of the therapeutics for gram negative bacterial infection. Increasing of organisms producing metallo-β-lactamase (MBL), we have difficulty in choosing the antimicrobial agents. Among 345 clinical isolates of Pseudomonas spp., 61 isolates (17.7%) were positive for the modified imipenem or meropenem-Hodge test and 55 isolates (15.9%) were positive for the imipenem-EDTA + SMA double disk synergy test (DDS). PCR and sequencing of bla_VIM-2-allele and bla_IMP-1-allele showed that 17 isolates of Pseudomonas aeruginosa, 9 isolates of Pseudomonas taiwnensis and 2 Pseudomonas plecoglossicida had bla_VIM-2, and 22 isolates of P. aeruginosa and one Pseudomonas otitidis had bla_IMP-6. These MBL genes were all in class 1 integron. The size of class 1 integron with bla_VIM-2 ranged from 3.5 kb to 5.5 kb in clinical isolates of Pseudomonas spp. including P. aeruginosa. bla_VIM-2 was most often located first in the class 1 integron, sometimes in the second or third position, and these integrons often had aacA4 or aadA1. Strict infection control measures are needed to more effectively prevent further spread of these MBL-producing Pseudomonas spp. In addition, MBL-producing Pseudomonas spp. is expected to continue to spread in various countries and regions.

• Mycobiology
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• v.48 no.2
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• pp.148-152
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• 2020

We investigated the antifungal susceptibilities and the cyp51 mutant strains among Aspergillus fumigatus clinical isolates obtained from 10 university hospitals in Korea. Of the 84 isolates examined, two itraconazole-resistant isolates were found with no amino acid substitution in the cyp51A/cyp51B genes. However, 19 (23.2%) azole-susceptible isolates harbored amino acid substitutions: Nine isolates harbored one to five mutations in cyp51A with high polymorphism, and 11 isolates exhibited the same Q42L mutation in cyp51B. Overall, a low azole resistance rate and high frequency of cyp51A/cyp51B amino acid substitutions were observed in the azole-susceptible A. fumigatus isolates in Korea.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.23-23
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• 2003

Chestnut blight, caused by Cryphonectria parasitica, is the most destructive disease of American and European chestnut trees. A total of 672 C prasitica was isolated from blight lesion on chestnut twigs, which were collected from major chestnut plantations all over Korea in 1999. Isolation rates were over 30% in Kyunggj-, Kyongnam-, and Chonnam-do. The highest isolation rate was 37.4% and recorded in Kyongnam-do. On the other hand, Chonbuk-do had the lowest isolation rate as 13.5%. In grouping of C parasitica by colony shape and color, yellow colony with irregular margin were the most dominant colony type with a frequency of 65.2%. When the 672 isolates were inoculated on the chestnut twigs, 380 isolates (56.5%) caused lesions larger than the standard virulent isolate EP155-2, while 158 isolates (23.4%) caused smaller lesions than the standard hypovirulent isolate UEP-1. In Bavendamm test that determines phenol oxidase activity, 97.1% of all the isolates resulted the same or darker discoloration than EP155-2, and only 12.2% resulted the same or lighter discoloration than UEP-1. In the vegetative compatibility (VC) tests, total 670 isolates were divided into 121 VC groups (VCGs). Kyongnam-, Chonnam-, and Chungnam-do, the three principal chestnut plantation area, had 49, 33, and 27 VCGs, respectively. Among the VCGs, the biggest VCG, KR-VC104, was composed of 164 isolates and the second biggest VCG had 62 isolates. But, 64 of 121 VCGs consisted of sole member. More than 65.8% of KR-VC104, was isolated from the three provinces, Kyongnam-, Kangwon-, and Chungbuk-do. In KR-VC104, 62.8%, 59.1%, and 85.9% of the isolates looked like virulent in colony type, pathogenicity test, and Bavendamm test. In ds-RNA detection tests using cellulose chromatography, 77 of total 650 isolates were ds-RNA positive and detected ds-RNA segments were approximately 12kb, 3kb, 2.7kb, 2kb, and 1.8kb in size. Among the 77 isolates, 46 isolates had 12kb and 25 isolates had 12kb and 2.7kb. Other 6 Isolates had small ds-RNA segments. Kyongnam-, Chonnam-, and Chungnam-do had 43, 16, and 5 ds-RNA positive isolates, respectively. Among the 121 VCGs, only 29 VCGs had ds-RNA positive isolates.(중략)

• Journal of Microbiology and Biotechnology
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• v.10 no.5
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• pp.620-627
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• 2000

To determine the prevalence of genetic polymorphisms in Epstein-Barr virus (EBV) strains in the Korean population, the restriction site polymorphisms for BamHI and XhoI enzymes were analyzed with 16 EBV isolates from cancer patients and 7 EBV isolates from healthy carriers, using polymerase chain reaction techniques. None of the 23 isolates were found to carry an extra BamHI site in the BamHI F-fragment (f-variant). Of the 12 type-1 isolates from the cancer patients, 10 lost both the LMP1 XhoI site and the BamHI site between the BamHi W1* and I1* fragments (a W1*I1* fusion variant or type C). The latter W1*I1* fusion variant was due to a mutation of thymidine to adenine, as evidenced by a sequence analysis. The remaining two type-1 isolates showed either no variation at both sites or the loss of only the XhoI site. In contrast, two type-2 isolates and two intertypic recombinants with a type-1 allele at the EBNA2 locus and type-2 alleles at all or some of the EBNA3 loci retained both enzyme sites. In similar analyses of the 7 isolates from the healthy carriers, five of six type-1 isolates lost these two sites, however, one type-2 isolate did not. These results clearly indicate a strong association of both the LMP1 XhoI site loss and the W1*I1* fusion variant with the type-1 rather than the type-2 EBV strains circulating in the immunocompetent Korean carriers.

• The Plant Pathology Journal
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• v.26 no.1
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• pp.83-89
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• 2010

Taxonomic position of 46 Korean isolates of Rhizoctonia solani which were classified into nine intraspecific groups by anastomosis and cultural characteristics was analyzed by randomly amplified polymorphic DNA (RAPD) and sequence analyses of the internal transcribed spacer (ITS) regions of ribosomal DNA. All the isolates within each group showed highly similar band patterns in RAPD. The ITS regions of the isolates within the same groups showed a high level of sequence similarity above 96.0% whereas similarities among different groups were below 94.4%. When compared with several reference strains of R. solani from foreign countries, all the Korean isolates were clustered with the foreign isolates belonging to the same groups in the phylogenetic tree. All six Korean strains of AG-4 were identified as HG-1 out of 3 subgroup of AG-4. We discussed taxonomic position of Korean isolates of R. solani and showed that sequence analysis with ITS regions could be a rapid and useful method for identification of intraspecific group of R. solani.