• Microbiology and Biotechnology Letters
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• v.25 no.3
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• pp.240-247
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• 1997

Bacillary is the most common form of H. pylori observed during human infection. However, it is known that the morphology change of H. pylori from bacillary to coccoid can be occurred with a response to the environmental stresses such as the nutrient depletion, accumulation of toxic metabolites, pH alteration, and exposure to antimicrobial agents. The coccoid form of H. pylori, which is viable but non-culturable in vitro, seems to be the major cause of antibiotic resistancy and high reinfectability of H. pylori. In this regard, we studied the environmental factors that can induce the morphological change in vitro of H. pylori, and the change of fatty acid composition of plasma membrane. The morphological change from bacillary to coccoid could be observed with the depletion of nutrients, pH variation and reactive oxygen species added in the culture media. This morphologic conversion was paralleled by a dramatic decrease in unsaturated fatty acids and an increase in saturated fattv acids of plasma membrane. The change in composition of membrane fatty acid seems to be a kind of protection mechanism of H. pylori against these environmental stresses.

• ALGAE
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• v.23 no.4
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• pp.269-276
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• 2008

We have conducted the study of distribution and inhabitation of the aerial algae from five stone cultural properties located in Gyeonggi-do. A total of 21 taxa were identified, among which 8 taxa of cyanophytes, 12 taxa of cholorophytes and one diatom species. Protococcus viridis, Ulothrix zonata, Synechocystis aquatilis and Chroococcus varius occurred in 15, 9, 8 and 7 study sites, respectively. These coccoid types appeared more frequently than filamentous types. In this study, Chlorococcum infusionum, Cylindrocystis gracilis, Klebsormidium crenulatum, Klebsormidium dissectum and Klebsormidium flaccidium newly recorded from Korea. We found that 80% of stone cultural properties had aerial algae and their 58-84% were grouped into Class 5 based on chlorophyll-a concentration.

• Journal of Microbiology and Biotechnology
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• v.17 no.2
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• pp.202-206
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• 2007

The adhesion of Campylobacter jejuni to chicken skin, along with the associated morphological changes under aerobic conditions at 4, 25, and $37^{\circ}C$ and microaerobic ($O_2\;5%,\;CO_2\;10%,\;N_2\;85%$) conditions, were investigated using confocal laser scanning microscopy (CLSM), flow cytometry, and plate counting. The morphological change of C. jejuni from a spiral shape to a coccoid form or VBNC form (viable but nonculturable form) progressed rapidly under aerobic conditions at 25, 37, and $4^{\circ}C$. As regards adhesion, the C. jejuni cells were mostly located in the crevices and feather follicles of the chicken skin, where the cells in the feather follicles floated freely in the entrapped water, even after the skin was rinsed quite thoroughly. CLSM also revealed the penetration of some spiral-shaped C. jejuni cells into the chicken skin. Even after changing their shape at various temperatures, coccoid-form C. jejuni cells were still found in the crevices and feather follicles of the chicken skin.

• Korean Journal of Veterinary Service
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• v.34 no.1
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• pp.55-61
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• 2011

Dermatopathologic findings on cutaneous streptothricosis (bovine dermatophilosis) were conducted in Dinajpur of Bangladesh for one year. The animals were examined clinically at hospital during the physical visit of the affected animals and clinical manifestations and patients' history were recorded. The gross lesions were systematically examined, noted and categorized. An impression smear was made by the skin scraps, stained with Gram's stain and examined microscopically for the presence of causative bacteria. The suitable sizes of skins of 3 animals typically affected with dermatophilosis were collected surgically from the animals, and prepared for the histopathological study. The cardinal clinical features and gross lesions were characterized as paint-brush cutaneous surface with matted hairs, scab and crust formation, roughened coat; istopathologically as hyperkeratosis, parakeratosis, typical "palisading encrustations", extensive proliferation of coccoid shaped, bluish coloured bacteria (zoospores) in the cells of the outer rootsheath of the hair follicles, separation of keratinized layer from the epidermal epithelium, epidermal hyperplasia, densely cellular dermis with moderate destruction of glandular structures. Coccoid shaped gram positive organisms which form multidimensional arrangement were also observed by impression smear. The clinical signs, gross lesions, morphology of the organisms, staining properties, and histopathological features of the affected skin were diagnostic criteria for the bovine cutaneous streptothricosis.

• Microbiology and Biotechnology Letters
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• v.33 no.4
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• pp.302-307
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• 2005

The inactivation efficiency of Campylobacter jejuni were assessed in vitro and in vivo using confocal laser microscopy and flow cytometry. C. jejuni cells were inactivated with $1\%$ (w/v) trisodium phosphate (TSP) and the live cells and inactivated cells were distinguished by staining with LIVE/DEAD BacLight Bacteria Viability fluorescent probe. After treatment of TSP for 5 min, most of C. jejuni cells turned to coccoid form from original spiral shape. C. jejuni cells lost total cell viability in the absence of organic nutrients but did not lost total cell viability in the presence of organic nutrients. In vivo test, C. jejuni cells turned to viable but non-culturable (VBNC) form after TSP treatment and remained alive on chicken skin. C. jejuni cells attached on chicken meat would transform to coccoid form by sanitizer treatment, but could possibly be alive by the benefits of organic nutrients present in chicken meat.

• Journal of Microbiology and Biotechnology
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• v.14 no.6
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• pp.1227-1231
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• 2004

Campylobacter, one of the emerging foodborne pathogens, is highly adaptable to the external environments by changing its morphology. In the present study, a question of whether the whole-cell antibody would still be effective for its detection even though the morphology of C. jejuni was changed was examined. When microaerophilic C. jejuni was exposed to aerobic conditions for 48 h, its morphological change was detected by confocal laser scanning microscope: Its morphology was confirmed as a spiral-bacilli form in microaerobic condition, however, as a coccoid form with a little spiral-bacilli form, when exposed to aerobic conditions. Also, the expressions of the whole-cell proteins of C. jejuni, and the suppression or induction of newly synthesized proteins in both aerobic and microaerobic conditions were analyzed by two dimensional gel electrophoresis. Additionally, immunoblotting assay with the whole cell antibody for the proteins expressed under the two conditions was performed. It was confirmed that the commercial whole-cell antibody of C. jejuni raised in rabbit was reactive. When analyzed with MALDI- TOF MS, the expressed proteins were confirmed as flagellins. Therefore, even though the morphology changed in aerobic condition, these flagellins were expressed and worked as the eitope proteins, thus making it possible to utilize for the development of an immunosensor for real-time detection of any kind of C. jejuni cell.

• Food Science of Animal Resources
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• v.33 no.3
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• pp.317-324
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• 2013

Radio-frequency driven atmospheric pressure plasma using argon gas was studied in the inactivation of Campylobacter jejuni in order to investigate its applicability. First, the inactivation study was conducted on an agar surface. C. jejuni NCTC11168 was reduced by more than 7 Log CFU after an 88 s treatment. Another strain, ATCC49943, was studied; however, the inactivation was less efficient, with a 5 Log CFU reduction after a 2 min treatment. Then, chicken breast ham was studied at the $10^6$ CFU inoculation level. The inactivation efficiency was much lower for both strains compared to that on the agar plates. C. jejuni NCTC11168 and ATCC49943 were reduced by 3 Log CFU after a 6 min treatment and by 1.5 Log CFU after a 10 min treatment, respectively. The scanning electron microscopy analysis indicated that C. jejuni cells were deformed or transformed into coccoid form under the plasma treatment. During the plasma treatment, the temperature of the samples did not rise above $43^{\circ}C$, suggesting that heat did not contribute to the inactivation. Meanwhile, water activity significantly decreased after a 10 min treatment (p<0.05). This study conveyed that radio-frequency atmospheric pressure plasma can effectively inactivate C. jejuni with strain-specific variation.

• Korean Journal of Veterinary Research
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• v.33 no.4
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• pp.633-647
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• 1993

NC strain mice were inoculated intraperitoneally with Dermatophoilus-like microorganism strain W254 isolated from the sulfur granules of the swine tonsils. The development of the resulting abscesses in NC strain mice was investigated at regular time intervals by means of histological, histochemical and electron microscopical methods. The results obtained were as follows ; 1. The inoculated bacteria have settled in the subserous site of the peritoneal organ and provoked cellular response to form neutrophil, macrophage and connective tissue layers at the time of one week after inoculation, and thereafter were found to have formed typical actinomycotic abscess two weeks after inoculation. 2. The persistant abscesses were appeared to reveal close interaction between higher activity of organism and tissue reaction and contained hyaloid bodies within or outside bacterial clumps. 3. The hyaline materials were appeared to be composed of protein rich in hydroxyphenyl group by histochemical examination. The materials were presumed to be produced by the interaction between bacterial activity and host cell reaction. 4. The bacteria in the abscesses showed the various developmental stages of coccoid body, mulberry-like body tuber-shaped body and filamentous body, and it was confirmed that the mesosomal development was related to septation of the bacterial cells.

• Journal of Microbiology and Biotechnology
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• v.15 no.5
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• pp.992-1000
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• 2005

Campylobacter is one of the emerging foodborne pathogens, and its worldwide incidence rate is extremely high. This study was undertaken to isolate and identify Campylobacter strains from chicken carcasses in the local markets, and analyze their characteristics regarding oxygen tolerance. They were isolated after aerobic enrichment and identified by biochemical, physiological, and morphological characteristics, PCR, and 16S rDNA sequencing. Their oxygen tolerances were analyzed in terms of the cell surface hydrophobicity, cell fatty acid composition, and oxidoreductase. Five strains of C. jejuni were isolated and identified from 61 isolates from 50 chickens. Among them, C. jejuni IC21 grew well in Brucella broth and commercial milk under aerobic condition. However, in the aerobic exposure, the cell surface hydrophobicity of C. jejuni IC21 was almost the same as the other isolates, even though its morphology changed from the spiral-bacilli form into the coccoid form. Fatty acid analyses showed that all Campylobacter strains had a high composition of $C_{19:1}$, cyclopropane fatty acid, and that the amount of the other fatty acids were very similar between them. Interestingly, however, only oxidoreductase activities of C. jejuni IC21 increased highly under aerobic exposure even though its activities were almost the same as the other C. jejuni strains just after microaerobic culture. It had 11.8 times higher catalase activity, 4.4 times higher for SOD, and 2.0 times higher for NADH oxidase activities. Therefore, in the case of the aero-adaptive C. jejuni IC21, expression of oxidoreductase significantly increased under oxidative stressed condition, which might allow it to survive for a longer time and grow on food under aerobic exposure. Such new strain might be one of the explanations for the increase of campylobacteriosis.