• The Plant Pathology Journal
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• v.18 no.4
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• pp.225-227
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• 2002

Moth orchid plants with yellowing blight and root rot symptoms were collected, and a total of 54 isolates of Fusarium spp. was obtained from roots and leaf bases of the diseased plants. The isolates were identified based on their morphological characteristics. Out of the 54 isolates of Fusarium spp., 42 isolates were identified as F. solani, 5 isolates as F. oxysporum, and 7 as F. proliferatum. Isolates of the three Fusarium spp. were tested for pathogenicity to moth orchid plants by artificial inoculation. All the Fusarium spp. induced root rot of the host plants. The symptoms progressed up to the basal part of the leaves, which later caused yellowing blight. The symptoms induced on the plants by artificial inoculation with the Fusarium spp. isolates were similar to those observed in greenhouses. The present study reveals that F. oxysporum, F. proliferatum, and F. solani cause root rot of moth orchid, and that F. solani is the main pathogen of the disease.

• Mycobiology
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• v.31 no.2
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• pp.113-118
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• 2003

Solanaceous crops grown in greenhouses and fields in Korea were surveyed from 1994 to 2000. Sclerotinia rot most severely occurred up to 60% in potato. Incidence of the disease was as high as 20% at its maximum in tomato and 5% in eggplant, but as low as less than 1% in red pepper. Symptoms of Sclerotinia rot commonly developed on stems of the solanaceous crops but rarely on fruits of eggplant and tomato. A total of 169 isolates of Sclerotinia species was obtained from the diseased solanaceous crops. Out of the isolates, 165 isolates were identified as S. sclerotiorum, and the others as S. minor based on their morphological and cultural characteristics. S. sclerotiorum was isolated from all the solanaceous crops, while S. minor was only isolated from tomato. Eight isolates of S. sclerotiorum and two isolates of S. minor were tested for their pathogenicity to the solanaceous crops by artificial inoculation. All the isolates of the two Sclerotinia spp. induced rot symptoms on stems of the solanaceous crops tested, which were similar to those observed in the fields. The pathogenicity tests revealed that there was no significant difference in the susceptibility of the solanaceous crops to the isolates of S. sclerotiorum. However, in case of S. minor, the potato cultivar Sumi was relatively less susceptible to the pathogen.

• International Journal of Industrial Entomology and Biomaterials
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• v.33 no.2
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• pp.121-131
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• 2016

Ten microsporidian isolates from Samia cynthia ricini, and Antheraea assamensis in India along with a Nosema reference strain (NIK-1s_mys) from B. mori India were characterised morphologically and molecular based tools. The test isolates observed elongated oval in shape while reference strain was oval and ranging from 3.80 to 4.90 m in length and 2.60 to 3.05 m in width. The ribosomal DNA region 'IGS' of test isolates assessed by PCR amplification, followed by cloning and sequencing. IGS sequence and phylogenetic analysis of test microsporidian isolates showed very close relationship with three Nosema references species: N. philosamia, N. antheraea isolated from Philosamia cynthia ricini and Antheraea perny in China respectively and N. disstriae from Malacosma disstriae in Canada. The clustering pattern of dendogram reveals all test isolates appear distinct from Nosema std. (NIK-1s_mys) India used as reference strain in the study. The result suggests IGS indeed a suitable and highly applicable molecular tool for identifying and characterise the microsporidian isolates in similar population.

• The Plant Pathology Journal
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• v.27 no.3
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• pp.280-284
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• 2011

Fusarium wilt of banana caused by Fusarium oxysporum f. sp. cubense is widespread in Indonesia. However, the distribution of tropical race 4 strains has not been well studied. Thirty nine isolates of F. oxysporum f. sp. cubense were collected from Java and 7 isolates were from Sumatera, Bangka, and Kalimantan. All isolates produced volatile odor when grown on steamed rice. These isolates were further tested for their vegetative compatibility with nitM testers of 20 reported vegetative compatibility groups representing strains that belong to race 1, 2, and 4. Three isolates formed heterokaryons with nitM testers belong to race 1, 11 isolates with race 4, and the rest did not form heterokaryons with all nitM testers used. F. oxysporum f. sp. cubense tropical race 4 specific primer pair was used to amplify a 1400 bp fragment of tropical race 4 DNA. Seven isolates (Bnt2, Mln1, Srg1, Bgl3, Bgl6, Lmp1, and Kjg1) produced the 1400 bp amplification product were therefore tropical race 4.

• Microbiology and Biotechnology Letters
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• v.32 no.3
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• pp.218-223
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• 2004

Myxobacteria are Gram-negative soil bacteria known to be a rich source of potentially useful secondary metabolites. We have isolated 204 strains of bacteriolytic myxobacteria from soil samples collected in Korea and determined their 16S rRNA sequences. Sequence analysis of the partially determined 16S rRNA sequences has suggested that 132 isolates (65% of total isolates) belong to the genus Myxococcus and 59 isolates (29% of total isolates) belong to the genus Corallococcus. Meanwhile, 4 isolates appear to be Archangium spp. and the other 4 isolates appear to be Stigmatella spp. Genera of the remained 5 isolates have not been identified because their 16S rRNA sequences are distantly related to those of known myxobacteria.

• Clinical and Experimental Pediatrics
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• v.56 no.8
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• pp.332-337
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• 2013

Purpose: To identify the frequency of bacterial isolates in early-onset neonatal sepsis (EONS) and their antimicrobial resistance pattern. Methods: A retrospective study of EONS was conducted at the Beni Suef University Hospital from September 2008 to September 2012. A case of EONS was defined as an infant who had clinical signs of infection or who was born to a mother with risk factors for infection, and in whom blood culture obtained within 72 hours of life grew a bacterial pathogen. Results: Of 673 neonates screened, there were 138 positive blood cultures (20.5%) (confirmed EONS). Of the recovered isolates, 86.2% were gram-negative pathogens. Klebsiella pneumoniae (42.8%), Enterobacter cloacae (22.5%), and Escherichia coli (13.8%) were the commonest isolated organisms. The most common gram-positive microorganism was Staphylococcus aureus accounting for only 12 isolates (8.7%). All Klebsiella isolates and 93% of Enterobacter isolates were resistant to ampicillin. Gram-negative pathogens had the maximum overall sensitivity to imipenem, cefepime, and ciprofloxacin; whereas, gram-positive isolates were most susceptible to vancomycin, imipenem, and piperacillin. Conclusion: K. pneumoniae was the predominant causative bacteria of EONS followed by E. cloacae and E. coli. There was a high resistance to ampicillin. Imipenem had the maximum overall activity against the causative bacteria. Continuous surveillance is needed to monitor the changing epidemiology of pathogens and antibiotic sensitivity.

• Research in Plant Disease
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• v.10 no.2
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• pp.130-134
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• 2004

The pathogenesity of 25 isolates of Colletotrichum gloeosporioides from apple, 42 isolates from pepper, 5 isolates from jujube, 8 isolates from persimmon was evaluated to know transmission to strawberry from other infected plants. Followings are the results. Colony morphology and spore size on potato dextrose agar was similar. When each isolate was inoculated on leaf and petiole of strawberry, isolates from persimmon was the most pathogenic. Five isolates, one pathogenic isolate per each host, were evaluated in simulated field condition under natural rainfall for their natural infectivity. All isolates infected strawberry in field condition, so C. gloeosporioides from other hosts are potential inoculum source of strawberry anthracnose.

• The Plant Pathology Journal
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• v.19 no.3
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• pp.152-158
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• 2003

Stromata of the white root rot fungus, Rosellinia necatrix, were produced on diseased roots although they were reported to develop rarely in nature. Forty-two (42) out of 47 samples produced synnemata while 23 developed stromata. Forty-seven (47) isolates obtained from diseased root samples were divided into 24 mycelium compatibility groups (MCGs). Sixteen (16) out of 24 MCGs produced stromata. Single ascospore isolates from 10 stroma samples produced dsRNA-containing isolates from diseased tissue beneath stromata. The frequency of synnema production on axenic culture varied among isolates with different origin. The dsRNA was not transmitted vertically to the ascospore offspring despite the infection of various dsRNA in the parental isolates. The dsRNA was absent in 35 ascospore isolates in two stroma samples that originated from the isolates, in which dsRNA was not eliminated by hyphal tip isolation. Consequently, sexual reproduction in the white root rot fungus was suggested to produce propagules as a new infection source and to have the function to eliminate infectious factors such as mycoviruses.

• Mycobiology
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• v.40 no.3
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• pp.189-194
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• 2012

Four Cladobotryum isolates were collected from four different commercially grown mushroom types infected with cobweb disease in Cheongdo-gun and Chilgok-gun of Gyeongbuk Province, Korea in 2010. The isolates were identified as C. mycophilum from Agaricus bisporus and Pleurotus eryngii, C. varium from Flammulina velutipes and Hypsizygus marmoreus. The cultural characteristics of the four isolates were investigated using potato dextrose agar (PDA) media under nine different temperatures ranging from $5{\sim}32^{\circ}C$. Rapid growth of the isolates to colony diameters of 47~82 mm was observed at conditions of $18{\sim}22^{\circ}C$. No growth was observed at $32^{\circ}C$. C. mycophilum produced a yellowish red pigment while C. varium produced a cream colored pigment after cultivation for 25 days on PDA. Phylogenetic analysis of the internal transcribed spacer region and partial 28S rDNA from the four isolates confirmed they were C. mycophilum and C. varium. Cross pathogenicity tests revealed that the two isolates of C. mycophilum were highly pathogenic toward three mushroom types, but not toward H. marmoreus. The two isolates of C. varium were less pathogenic than those of C. mycophilum, but were pathogenic toward all mushroom types evaluated.

• Mycobiology
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• v.35 no.4
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• pp.230-234
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• 2007

In order to breed a Cordyceps bassiana isolate that stably forms fruiting body in artificial cultivation, isolates derived from subculturing and single spores were tested through mating. From C. bassiana EFCC 783, three subcultured isolates EFCC 2830, EFCC 2831 and EFCC 2832 were obtained and fourteen single conidial isolates were obtained from these three subcultured isolates. Two different morphological types were found in the fourteen single conidial isolates. One type was able to form synnemata and another type was not able to form synnemata. Since switch of morphological type was not observed despite their continuous subculturing, cross was performed between the two types and the formation of fruiting body was examined. Ascospores were obtained from a selected fruiting body formed by hybrid of the cross. Self-cross and combinational cross of the ascospore-derived isolates generated hybrids that stably produce high quality fruiting body in artificial media.