• The Plant Pathology Journal
• /
• 제17권6호
• /
• pp.336-341
• /
• 2001

The distribution of citrusphages and phage types of Xanthomonas axonopodis pv. citri was investigated in Korea. Forty-eight strains of the bacterial pathogen and 28 bacteriophage strains were isolated from citrus leaves showing the citrus canker symptom. Only a single bacteriophage group, named CPK, was identified based on their aggressiveness to the bacterial pathogen. The bacterial strains were differentiated into two Iysotypes based on their sensitivity to CPK. Lysotype I, which was sensitive to CPK, was more predominant (96%), while only 4% belonged to Iysotype II, which was resistant to CPK. Among the 13 xanthomonads including Iysotype A and Iysotype B of X axonopodis pv. citri, CPKs were only aggressive to BC 83 (=Xc 62) strain of X. axonopodis pv, citri reported as Iysotype A. Thus, bacterial pathogens and citrusphages related to citrus plants mainly distributed in Korea were presumed as Iysotype A of X. axonopodis pv, citri, and Iysotype A-infecting CP$_1$ respectively.

• 한국자기공명학회논문지
• /
• 제21권3호
• /
• pp.78-84
• /
• 2017

Pseudin is a naturally occurring 24 amino-acid-residue antimicrobial peptide derived from the skin of paradoxical frog Pseud's paradoxa. It shows potency against the bacteria and antibiotic-resistant bacteria strain, but has high cytotoxicity against mammalian cell. In our previous study, substitution of $Pro^{11}$ for Gly (Ps-P) increased bacterial cell selectivity but decreased the antibacterial activity of pseudin. In this study, we designed pseudin analogue, Ps-4K-P with increased cationicity up to +7 in Ps-P by substituting Glu14, Gln10, Gln24, and Leu18 with Lys. Ps-4K-P showed improved potent antibacterial activity with high bacterial cell selectivity. We determined the tertiary structure of Ps-4K-P in the presence of DPC micelles by NMR spectroscopy and it has a hinge structure at $Pro^{11}$ followed by three turn helices from $Pro^{11}$ to $Val^{23}$ at the C-terminus. Amphipathicity with increased cationicity as well as helix-hinge-helix structural motif provided by introduction of a Pro at position $Gly^{11}$ are the crucial factors which confer antibacterial activity with bacterial cell selectivity to Ps-4K-P.

• 약학회지
• /
• 제55권1호
• /
• pp.22-31
• /
• 2011

This systematic review was conducted to assess the clinical effect of ocular fluoroquinolones used for the treatment of bacterial conjunctivitis. A literature search for randomized controlled clinical trials registered up to January 2010 based on PubMed database, using the following search terms: conjunctivitis and fluoroquinolones (besifloxacin, moxifloxacin, gatifloxacin, levofloxacin, lomefloxacin, ciprofloxacin and ofloxacin) were performed. Pooled data on the clinical resolution and bacterial eradication rates derived from selected 16 studies were reported as the relative risk (RR) and 95% confidence interval (95% CI) compared with placebo. Early clinical resolution and microbiological eradication rates in placebo were 28% and 62% respectively. Fluoroquinolones were significantly effective comparing to placebo: early RR 1.94 (95% CI 1.60~2.34) and late RR 1.30 (1.19~1.43) in clinical resolution rates, and early RR 1.75 (1.58~1.94) and late RR 1.28 (1.18~1.39) in microbiological eradication rates. Besifloxacin, ciprofloaxain and moxifloxacin in clinical resolution, and besifloxacin and levofloxacin in microbiological eradication showed higher RRs than pooled overall fluoroquinolones' RRs. New quinolones had higher antibacterial potencies for all pathogens isolated from bacterial conjunctivitis and resistant isolates than old generation quinolones. In conclusion, ocular 7 fluoroquinolones were all effective than placebo for bacterial conjunctivitis and there were differences between quinolones in early and late clinical resolutions and microbiological eradications, and no differences in safety comparing to placebo.

• Journal of Species Research
• /
• 제10권2호
• /
• pp.99-116
• /
• 2021

In 2018, as a subset study to discover indigenous prokaryotic species in Korea, a total of 18 unreported bacterial strains were discovered. From the high 16S rRNA gene sequence similarity (>98.8%) and formation of a robust phylogenetic clade, it was determined that each strain belonged an independent and predefined bacterial species. There were no official report that these 18 species were previously described in Korea; therefore, one strain of Williamsia, one strain of Rhodococcus, three strains of Microbacterium, three strains of Agromyces, one strain of Arthrobacter, one strain of Paeniglutamicibacter, one strain of Pseudarthrobacter, one strain of Nocardioides, one strain of Fibrella, one strain of Hymenobacter, one strain of Deinococcus, two strains of Fictibacillus, and one strain of Paenibacillus are described as unreported bacterial species in Korea. Gram reaction, basic biochemical characteristics, and colony and cell morphologies are described in the species description section.

• Journal of Species Research
• /
• 제10권4호
• /
• pp.321-335
• /
• 2021

In 2020, a total of 12 bacterial strains were isolated from soil after a comprehensive investigation of indigenous prokaryotic species in Korea. It was determined that each strain belonged to independent and predefined bacterial species, with high 16S rRNA gene sequence similarity (>98.7%) and formation of a robust phylogenetic clade with the closest species. This study identified four families in the phylum Actinobacteria, two families in the phylum Proteobacteria, one family in the phylum Bacteroidetes one family in the phylum Firmicutes; and four species in the family Nocardiaceae, two species in the family Nocardioidaceae, one species in the family Cellulomonadaceae, one species in the family Hymenobacter, one species in the family Methylobacteriaceae, one species in the family Microbacteriaceae, one species in the family Bacillaceae and one species in the family Sphingomonadaceae. There is no official report of these 12 species in Korea, so they are described as unreported bacterial species in Korea in this study. Gram reaction, basic biochemical characteristics, colony, and cell morphology are included in the species description section.

• Journal of Animal Science and Technology
• /
• 제66권1호
• /
• pp.57-78
• /
• 2024

In a global context, bacterial diseases caused by pathogenic bacteria have inflicted sustained damage on both humans and animals. Although antibiotics initially appeared to offer an easy treatment for most bacterial infections, the recent rise of multidrug-resistant bacteria, stemming from antibiotic misuse, has prompted regulatory measures to control antibiotic usage. Consequently, various alternatives to antibiotics are being explored, with a particular focus on bacteriophage (phage) therapy for treating bacterial diseases in animals. Animals are broadly categorized into livestock, closely associated with human dietary habits, and companion animals, which have attracted increasing attention. This study highlights phage therapy cases targeting prominent bacterial strains in various animals. In recent years, research on bacteriophages has gained considerable attention, suggesting a promising avenue for developing alternative substances to antibiotics, particularly crucial for addressing challenging bacterial diseases in the future.

• Journal of Microbiology and Biotechnology
• /
• 제19권2호
• /
• pp.204-207
• /
• 2009

We investigated novel antibacterial and synergistic activities of isocryptomerin isolated from Selaginella tamariscina. Isocryptomerin showed potent antibacterial activity against Gram-positive and Gram-negative bacterial strains including clinical isolates of antibiotic-resistant species such as methicillin-resistant Staphylococcus aureus(MRSA). Additionally, we further investigated the synergistic activity of isocryptomerin with a conventional antibiotic against MRSA. The result indicated that isocryptomerin had considerable synergistic activity in combination with cefotaxime. In summary, the present study suggests that isocryptomerin may have potential as a novel therapeutic agent for treatment of infectious diseases by not only human pathogenic bacteria but also multidrug-resistant bacteria.

• 대한미생물학회지
• /
• 제35권5_6호
• /
• pp.354-354
• /
• 2000

• 농업과학연구
• /
• 제4권2호
• /
• pp.191-198
• /
• 1977

수도(水稻) 고병유전(枯病遺傳) 양식(樣式)과 백엽고병(白葉枯病) 저항성(抵抗性)과 출수기(出穗期)와의 관계(關係)를 구명(究明)하기 위(爲)하여 본병(本病)에 이병성(罹病性)인 TN1, IR 24를 모본(母本)으로 하고 저항성(抵抗性)인 IR 1545-339-2, IR 1544-340, IR 1698-237-2, 62-595, Kele를 부본(父本)으로 한 조합(組合)과 이병성(罹病性)인 Yushin, Milyang 23을 모본(母本)으로 하고 IR 1529-680-3, IR 28, IR 29, RP 663-337-7-8-4-1-1, RP 291-20을 부본(父本)으로 한 교배조합(交配組合)의 $F_1$과 $F_2$에 백엽고병균계(白葉枯病菌系) 71-23, 76-1을 접종(接種)하여 다음과 같은 결과(結果)를 얻었다. 1. IR 1529-680-3, IR 28, IR 29, RP 663-337-7-8-1-1, RP 291-20, 62-595가 71-23 균계(菌系)에 의(依)한 저항성(抵抗性)은 단순우성유전자(單純優性遺傳子)에 의(依)해 교배(交配)되었다. 2. IR 1545-339-2, IR 1544-340, IR 1698-237-2 Kele가 71-23 균계(菌系)에 의(依)한 저항성(抵抗性)은 단순(單純) 열성(劣性) 유전자(遺傳子)에 의(依)해 지배(支配)되었다. 3. IR 1545-339-2, IR 1544-340, IR 1698-237-2가 76-1 균계(菌系)에 의(依)한 저항성(抵抗性)은 단순우성유전자(單純優性遺傳子)에 의(依)해 지배(支配)되었다. 4. 동일(同一) 저항성(抵抗性) 품종(品種)도 사용(使用)하는 균계(菌系)에 따라 유전양식(遺傳樣式)과 저항성(抵抗性) 품종(品種)도 사용(使用)하는 균계(菌系)에 따라 유전양식(遺傳樣式)과 저항성(抵抗性) 정도(程度)에 차이(差異)가 있었다. 5. 백엽고병(白葉枯病) 저항성(抵抗性)과 출수기(出穗期)와의 사이에는 아무런 관련성(關聯性)도 없었다.

• Journal of Microbiology
• /
• 제42권1호
• /
• pp.47-50
• /
• 2004

There are a number of studies that explain the metabolism and roles of metallic titanium and titanium-ion. One of the most intriguing results from these studies is the finding of metallic titanium having no bacteriostatic effects on oral bacterial species. In this research, the effects of titanium-ion on the growth of twenty-two bacterial species, some of which are commonly found in foods such as yoghurt, kimchi, and soy fermented products, were investigated. All but two bacteria, Escherichia coli and Pseudomonas aeruginosa appeared to be sensitive to titanium-ion. These two species were grown on 360 $\mu\textrm{g}$/$m\ell$ of titanium-ions, and they were found to be resistant to the titanium-ion. Both the wild-type and plasmid-cured E. coli showed good growth in a medium with 200 $\mu\textrm{g}$/$m\ell$ of titanium-ions. These results suggest that titanium-resistance was independent from the effects of the plasmid in E. coli.