• 한국미생물·생명공학회지
• /
• 제50권2호
• /
• pp.193-201
• /
• 2022

Methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) are major causes of hospital- and community-acquired infections. The treatment of biofilm-related infections caused by these bacteria is a global healthcare challenge. Therefore, the development of alternative therapeutics is required. An essential oil extracted from Curcuma zedoaria (CZ) Rosc, also known as white turmeric, has been reported to possess various antimicrobial activities. In the present study, we evaluated the antibiofilm activities of an ethanolic extract of the CZ rhizome against MRSA and MSSA. The results showed that the CZ extract with the highest sub-minimum inhibitory concentration (sub-MIC), 1/2 MIC (0.312 mg/ml), significantly inhibited biofilm production by up to 80-90% in both tested strains. Subsequently, we evaluated the ability of the CZ extract to prevent cell-surface attachment to a 96-well plate and extracellular DNA (eDNA) release from the biofilm. The CZ extract demonstrated an inhibitory effect on bacterial attachment and eDNA release from the biofilm biomass. The CZ extract may inhibit biofilm formation by preventing eDNA release and cell-surface attachment. Therefore, this CZ extract is a potential candidate for the development of alternative treatments for biofilm-associated MRSA and MSSA infections.

• 생태와환경
• /
• 제56권4호
• /
• pp.420-429
• /
• 2023

This study was designed to examine the immune response in Korean rockfish during water temperature fluctuation and to elucidate the factors contributing to streptococcal pathogenesis in cultured Korean rockfish, S. schlegeli. We investigated cumulative mortality against Streptococcus iniae (FP5228 strain) infection in the exposed Korean rockfish (39.7±5.8 g) to environmentally relevant temperature (Control, 23℃; High temperature, 28℃ and 23℃ and 28℃ with 12 hours interval exchange, 23↔28℃) for 48 hours. Also, the expression of the mRNA related to the immune response genes (heat shock protein 70, interleukin1β, lysozyme g-type and thioredoxin-like 1) were measured in spleen and head kidney by real-time PCR analysis in the exposed fish to thermal stress. In this study, the combined stress with bacterial challenge in fishes exposed to thermal stress lowered the survival rate than that of control (23℃). The cumulative mortality in the group of control, 28℃ and 23↔28℃ was 24%, 24% and 40% (P<0.05), respectively. Also, thermal stress modulated the mRNA level of immune related genes; heat shock protein 70, interleukin-1β, lysozyme g-type and thioredoxin-like 1 in Korean rockfish. The present study indicates that a high and sudden water temperature change affect immune responses and reduce the disease resistance in Korean rockfish.

• 한국어병학회지
• /
• 제32권2호
• /
• pp.105-111
• /
• 2019

Citurs unshiu Markovich is a medicinal product of dried tangerine peel (DTP). It is effective on antioxidation, and getting fame as a medicine and functional food. By utilizing DTP as a feed additive, we aim to enhance the growth rate, innate immunity, and bacterial infection resistance to Tilapia. The DTP extract was added to the feed weight by 0.1, 0.5, 1, 5% and then fed to tilapia for 7 days to evaluate the innate immunity parameter, growth rate and anti-bacterial activity. Innate immunity parameter results showed that the ROI was significantly higher in the 5% group added at high concentration, while showing decrease or no differences in other experimental groups. In other parameters, all the experimental groups showed no significant difference or decreased compared to the control group. The challenge test showed a high survival rate of 71% in the 0.5% group and the lowest in the control group (36%). For the growth rate, the feed efficiency was improved in all groups except for the 0.1% group compared to the control group. In conclusion, DTP extract has bacterial resistant effect in while not affecting innate immune system of fish. Also, it has shown the potential as a possible feed additive as it has brought the improvement on feed efficiency ratio.

• 한국어병학회지
• /
• 제10권2호
• /
• pp.143-152
• /
• 1997

$\beta$-Glucan을 경구 혹은 침지투여하여 조피볼락(Sebastes schlegeli)의 비특이적 방어기작을 향상시켜 세균성 질병에 대한 저항성을 증가시키는 면역자극제로서의 효과를 알아보고자 하였다. $\beta$-Glucan을 사료에 섞어 경구투여하거나 혹은 사육수에 현탁시켜 침지투여한 후 Vibrio ordalii, Staphylococcus epidermidis 및 Edwardsiella tarda를 주사하여 인위감염으로 $\beta$-glucan의 효능을 시험하였다. V. ordalii를 주사한 결과, 1% $\beta$-glucan을 30일 동안 경구투여한 시험구는 25%의 생존율을 보였으나 $\beta$-glucan을 투여하지 않은 대조구는 3일 이내에 모두 폐사하였다. S. epidermidis를 주사한 결과, 20 및 30일 경구투여구는 95%의 높은 생존율을 보였다. 그러나 E. tarda의 인위감염시 전혀 방어효과가 없었다. V. ordalii 사균혼합구 혹은 단독 침지 시험구는 주사 후 10일 동안 전혀 방어효과가 관찰되지 않았다. 이러한 결과로 볼 때 $\beta$-glucan의 경구투여는 S. epidermidis와 V. ordalii에 효과적이나 E. tarda에는 방어효과가 없는 것으로 나타났다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제30권4호
• /
• pp.576-584
• /
• 2017

Objective: To generate recombinant Bacillus subtilis (B. subtilis) engineered for expression of porcine ${\beta}-defensin-2$ (pBD-2) and cecropin P1 (CP1) fusion antimicrobial peptide and investigate their anti-bacterial activity in vitro and their growth-promoting and disease resisting activity in vivo. Methods: The pBD-2 and CP1 fused gene was synthesized using the main codons of B. subtilis and inserted into plasmid pMK4 vector to construct their expression vector. The fusion peptide-expressing B. subtilis was constructed by transformation with the vector. The expressed fusion peptide was detected with Western blot. The antimicrobial activity of the expressed fusion peptide and the recovered pBD-2 and CP1 by enterokinase digestion in vitro was analyzed by the bacterial growth-inhibitory activity assay. To analyze the engineered B. subtilis on growth promotion and disease resistance, the weaned piglets were fed with basic diet supplemented with the recombinant B. subtilis. Then the piglets were challenged by enteropathogenic Escherichia coli (E. coli). The weight gain and diarrhea incidence of piglets were measured after challenge. Results: The recombinant B. subtilis engineered for expression of pBD-2/CP1 fusion peptide was successfully constructed using the main codons of the B. subtilis. Both expressed pBD-2/CP1 fusion peptide and their individual peptides recovered from parental fusion peptide by enterokinase digestion possessed the antimicrobial activities to a variety of the bacteria, including gram-negative bacteria (E. coli, Salmonella typhimurium, and Haemophilus parasuis) and grampositive bacteria (Staphylococcus aureus). Supplementing the engineered B. subtilis to the pig feed could significantly promote the piglet growth and reduced diarrhea incidence of the piglets. Conclusion: The generated B. subtilis strain can efficiently express pBD-2/CP1 fusion antimicrobial peptide, the recovered pBD-2 and CP1 peptides possess potent antimicrobial activities to a variety of bacterial species in vitro. Supplementation of the engineered B. subtilis in pig feed obviously promote piglet growth and resistance to the colibacillosis.

• 대한수의학회지
• /
• 제47권3호
• /
• pp.291-298
• /
• 2007

Olive flounder, Paralichthys olivaceus is one of the most important cultured fish in Korea, its farming has been negatively impacted by viral, bacterial and parasitic diseases. Streptococcal infection was considered as a serious problem because of significant economic losses in olive flounder farm industry. The development and evaluation of vaccine for protection against infection by this agent were required. We evaluated the safety and efficacy of ${\beta}$-hemolytic Streptococcus (S.) iniae vaccine on olive flounder Three hundreds of flounders (weight $119.8{\pm}20.7g$, body length $22.6{\pm}1.4cm$) were reared in 0.5 tons aquaria in land-marine tank system. Seawater was provided from the sea of Inchon in Korea, and water temperature was set to $22^{\circ}C$ and $25^{\circ}C$ in the vaccination and challenge test, respectively. We used the formalin-inactivated ${\beta}$-hemolytic S. iniae (F2K) vaccine (M VAC INIAE; Kyoritsu seiyaku, Japan) originated in Japan. The vaccine was intraperitoneally administered to fish. Both of vaccinated group and control group were challenged with intraperitoneally injection by virulent S. iniae SI-36 isolates with $1.0{\times}10^7CFU/fish$ at 3 weeks after vaccination. Difference on mortality of control and vaccinated group (90.0 and 15.0%, 76.5 and 8.0% respectively) at two trials were found significant (p<0.05), and relative percent survival were 83.4% and 89.5%, respectively. The dead fishes were showed dark pigmentation of skin, abdominal extension, hemorrhagic ascites, and liver necrosis, and isolated the S. iniae strain from ascites, liver and kidney. We confirmed the safety and efficacy of ${\beta}$-hemolytic S. iniae vaccine by determinations of the optimal management condition and artificial challenge test in olive flounder.

• 한국응용과학기술학회지
• /
• 제37권4호
• /
• pp.1020-1033
• /
• 2020

본 연구에서는 인체에 해가 없으며 항균작용 및 항산화 효과가 있는 오배자, 계피, 로즈마리 추출물을 이용하여 천연방부제 소재로서의 활용 가능성을 연구하였다. 실험식물의 추출방법으로는 계피의 경우 70% ethanol 추출, 오배자는 열수추출법, 로즈마리는 70% ethanol 추출과 열수추출법을 이용하였다. 실험 방법으로는 항균력, DPPH를 통한 항산화능, 화장품의 challenge test, 화장품 안정성 및 안전성 평가를 진행하였다. 시험 결과, 항균력 시험에서 오배자 추출물은 세균류, 계피 추출물은 진균류에서 항균력이 우수, 로즈마리 추출물의 경우 항균력이 미비해 제외, 복합 추출물(오배자·계피)의 경우는 1:1비율로 조합한 복합 추출물(complex C)에서 항균효과, 복합 추출물의 최소저해농도(MIC)와 최소살균농도(MBC)에서는 5종의 실험균주에서 억제효과와 살균효과, 천연 단일 추출물과 복합 추출물(complex C)에서는 항산화능이 확인 되었다. 또한 합성 방부제 대신 complex C 10%를 화장품에 적용한 시험에서 제형의 안정성 및 안전성이 확인되었다. 따라서 본 연구를 통해 천연방부제 원료로서의 발전 가능성을 확인할 수 있었다.

• Molecules and Cells
• /
• 제27권5호
• /
• pp.563-570
• /
• 2009

We previously isolated the OsCBT gene, which encodes a calmodulin (CaM)-binding protein, from a rice expression library constructed from fungal elicitor-treated rice suspension cells. In order to understand the function of OsCBT in rice, we isolated and characterized a T-DNA insertion mutant allele named oscbt-1. The oscbt-1 mutant exhibits reduced levels of OsCBT transcripts and no significant morphological changes compared to wild-type plant although the growth of the mutant is stunted. However, oscbt-1 mutants showed significant resistance to two major rice pathogens. The growth of the rice blast fungus Magnaporthe grisea, as well as the bacterial pathogen Xanthomonas oryzae pv. oryzae was significantly suppressed in oscbt-1 plants. Histochemical analysis indicated that the hypersensitive-response was induced in the oscbt-1 mutant in response to compatible strains of fungal pathogens. OsCBT expression was induced upon challenge with fungal elicitor. We also observed significant increase in the level of pathogenesis-related genes in the oscbt-1 mutant even under pathogen-free condition. Taken together, the results support an idea that OsCBT might act as a negative regulator on plant defense.

• 생명과학회지
• /
• 제26권12호
• /
• pp.1409-1414
• /
• 2016

동애등에(Hermetia illucens)를 포함한 곤충은 불량환경에서 오랜 진화의 역사를 통해 병원균 침입에 대응하기 위하여 강력한 항균 펩타이드를 발현하는 선천성 면역기전을 보유하고 있다. 동애등에 생체 내 항균펩타이드를 인위적으로 유도하기 위하여, E. faecalis 포함한 5종의 세균을 한방침에 묻혀 주사하였다. 5종 세균에 의해 면역이 유도된 동애등에로부터 혈림프를 채취하여 각 세균에 따른 항균펩타이드 유도효과에 의한 항균활성을 그람양성균인 S. aureus와 그람음성균인 E. coli에 대해 비교 분석하였다. 그 결과, 고초균인 B. subtilis은 5종 세균 중 그람양성 및 음성균 둘 다에 대해서 가장 높은 항균활성을 나타내었다. B. subtilis ($1{\times}10^9cfu/ml$)에 의해 면역이 유도된 동애등에는 주사 후 24시간째 가장 강한 항균활성을 나타내었다. 또한 B. subtilis에 의해 면역이 유도된 동애등에는 가금류의 주요 병원균인 S. enteritidis, S. typhimurium 및 S. pullorum에 대해서도 높은 항균활성을 나타내었다. 이상의 결과로써, B. subtilis에 의해 면역이 유도된 동애등에는 가축 성장촉진용 항생제를 대체할 수 있는 사료첨가제로써 매우 유용할 것으로 판단된다.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제12권2호
• /
• pp.57-61
• /
• 2006

Suppressor of cytokine signaling (SOCS) is known to be as a negative feedback regulator in Janus kinase signal transducer and activator of transcription signaling. Highly conserved SOCS box domain was cloned from a Korean malaria vector, Anopheles sinensis. Sequence analysis indicates that it has identity to Anopheles gambiae (96%), Aedes aegypti (94%), Drosophila melanogaster (78%), Mus musculus (72%) and Homo sapiens (72%), respectively. Tissue specificity RT-PCR demonstrated that the expression level of AsSOCS transcript was high at abdomen, midgut, and ovary, whereas developmental expression patterns showed that the level of AsSOCS was high at egg, early pupae, and adult female. On the other hand, RT-PCR analysis after bacterial challenge showed that SOCS mRNA was strongly induced in larvae. In addition, it was also induced by various immune elicitors such as lipoteicoic acid, CpG-DNA, and laminarin. It seems that AsSOCS, repressor of JAK-STAT pathway, is highly conserved in mosquito, and may play an important role in mosquito innate immune response.