• International Journal of Oral Biology
• /
• 제39권4호
• /
• pp.207-213
• /
• 2014

Antimicrobial actions of reactive oxygen/nitrogen species (ROS/RNS) derived from products of NADPH oxidase and inducible nitric oxide (NO) synthase in host phagocytes inactivate various bacterial macromolecules. To cope with these cytotoxic radicals, pathogenic bacteria have evolved to conserve systems necessary for detoxifying ROS/RNS and repairing damages caused by their actions. In response to these stresses, bacteria also induce expression of molecular chaperones to aid in ameliorating protein misfolding. In this study, we explored the function of a newly identified chaperone Spy, that is localized exclusively in the periplasm when bacteria exposed to conditions causing spheroplast formation, in the resistance of Salmonella Typhimurium to ROS/RNS. A spy deletion mutant was constructed in S. Typhimurium by a PCR-mediated method of one-step gene inactivation with ${\lambda}$ Red recombinase, and subjected to ROS/RNS stresses. The spy mutant Salmonella showed a modest decrease in growth rate in NO-producing cultures, and no detectable difference of growth rate in $H_2O_2$ containing cultures, compared with that of wild type Salmonella. Quantitative RT-PCR analysis showed that spy mRNA levels were similar regardless of both stresses, but were increased considerably in Salmonella mutants lacking the flavohemoglobin Hmp, which are incapable of NO detoxification, and lacking an alternative sigma factor RpoS, conferring hypersusceptibility to $H_2O_2$. Results demonstrate that Spy expression can be induced under extreme conditions of both stresses, and suggest that the protein may have supportive roles in maintaining proteostasis in the periplasm where various chaperones may act in concert with Spy, thereby protecting bacteria against toxicities of ROS/RNS.

• 대한수의학회지
• /
• 제57권3호
• /
• pp.169-174
• /
• 2017

This study was performed to investigate the distribution of ticks and the rate of infection with severe fever with thrombocytopenia syndrome (SFTS) virus in ticks collected at Mt. Gwanak and the Seoul National University campus, Korea. Ticks (n = 273) were collected from May to October and included 76 Haemaphysalis longicornis (4 adult females, 72 nymphs), 49 Haemaphysalis flava (9 adult females, 3 adult males, 37 nymphs), and 148 Haemaphysalis spp. larvae. SFTS virus detection was performed by using one-step RT PCR and nested PCR. The SFTS virus was detected in 7 samples (1 Haemaphysalis longicornis nymph, 3 Haemaphysalis flava nymphs, and 3 Haemaphysalis spp. larva). The overall minimum field infection rate was 2.6%, whereas the minimum field infection rates of adult, nymphal, and larval ticks were 0%, 3.2%, and 2.0%, respectively. For a more accurate indication of the prevalence of SFTS virus in Korea, further in-depth investigations of tick species and SFTS virus occurrence over a larger area and longer period are needed.

• 생명과학회지
• /
• 제21권6호
• /
• pp.845-850
• /
• 2011

2008년부터 2010년까지 최근 3년 동안 부산지역에서 산발적으로 발생한 급성 위장관염 환자를 대상으로 유전자를 검사한 결과 4,101건 중 426건(10.4%)에서 노로바이러스를 확인하였다. 연도별 검출현황은 2008년에 14.7%(222/1,506), 2009년에 6.9%(95/1,384), 2010년에 9.0%(109/1,211)로 나타났다. 월별 분석 결과는 2008년에는 3월에 35.7%(50/140)로 가장 높은 검출율을 보였고, 2009년 역시 3월에 21.9%(23/105)로 높게 나타났으며, 2010년에는 1월에 23.8%(29/122)로 높은 검출율을 보여 겨울절기에 노로바이러스가 유행하는 것을 알 수 있었다. 반면 매해 7-8월 여름절기에는 노로바이러스가 거의 분리되지 않았다. 연령별 로는 1세 영아군과 13-19세 중등학생군에서 각각 20.9%로 가장 높은 검출율을 나타내었으며, 2-6세 소아군에서 17.5%, 20-29세군에서 13.4%, 7-12세 초등학생군에서 12.7%, 30-39세군에서 9.1%, 0세 신생아군에서 8.7%, 50-59세군에서 7.2%, 60-69세군과 70세이상군에서 각각 6.7%, 40-49세 4.5%로 확인되었다. 노로바이러스 양성 검체 340건에서 유전자형을 분석한 결과 GI군 7종류, GII군 13종류로 총 20종류가 검출되어 다양한 유전자형의 노로바이러스들이 유행함을 알 수 있었다. 연구 결과 부산지역에서는 GI군이 21.8%(76/348), GII군이 78.2%(272/348)로 GII군이 우세하여 유행하였고, 유전자형 총 20종 중 GII.4형이 49.1%로 가장 많이 검출되었다.

• Fisheries and Aquatic Sciences
• /
• 제19권10호
• /
• pp.40.1-40.14
• /
• 2016

Background: Due to the paucity of oceanic resources utilized in the preparation of diets for cultured fish, commercial feed producers have been trying to replace fishmeal (FM) using alternative protein sources such as vegetable protein meals (VMs). One of the main drawbacks of using VMs in fish feed is related to the presence of a variety of anti-nutritional factors, which could trigger an inflammation process in the distal intestine. This reduces the capacity of the enterocytes to absorb nutrients leading to reduced fish growth performances. Methods: We evaluated the mitigating effects of butyrate and taurine used as feed additives on the morphological abnormalities caused by a soybean meal (SBM)-based diet in the distal intestine of sea bass (Dicentrarchus labrax). We used three experimental diets, containing the same low percentage of FM and high percentage of SBM; two diets were supplemented with either 0.2% sodium butyrate or taurine. Histological changes in the intestine of fish were determined by light and transmission electron microscopy. Infiltration of $CD45^+$ leucocytes in the lamina propria and in the submucosa was assessed by immunohistochemistry. We also quantified by One-Step Taqman$^{(R)}$ real-time RT-PCR the messenger RNA (mRNA) abundance of a panel of genes involved in the intestinal mucosa inflammatory response such as $TNF{\alpha}$ (tumor necrosis factor alpha) and interleukins: IL-8, IL-$1{\beta}$, IL-10, and IL-6. Results: Fish that received for 2 months the diet with 30% soy protein (16.7% SBM and 12.8% full-fat soy) developed an inflammation in the distal intestine, as confirmed by histological and immunohistochemistry data. The expression of target genes in the intestine was deeply influenced by the type of fish diet. Fish fed with taurine-supplemented diet displayed the lowest number of mRNA copies of IL-$1{\beta}$, IL-8, and IL-10 genes in comparison to fish fed with control or butyrate-supplemented diets. Dietary butyrate caused an upregulation of the $TNF{\alpha}$ gene transcription. Among the quantified interleukins, IL-6 was the only one to be not influenced by the diet. Conclusions: Histological and gene expression data suggest that butyrate and taurine could have a role in normalizing the intestinal abnormalities caused by the SBM, but the underling mechanisms of action seem different.

• 한국식품위생안전성학회지
• /
• 제25권2호
• /
• pp.153-161
• /
• 2010

충청지역권내 지하수를 사용하는 집단급식소의 식품용수 82시료의 norovirus 검출빈도를 조사한 결과 7시료에서 검출 되었으며, 이는 8.5%에 해당 하였다. Norovirus가 검출된 집단 급식소에 대해서는 식중독 발생이 우려됨에 따라 소독, 관정개발, 오염원제거 및 상수도 보급 등의 위생환경 개선과 유지관리가 필요하다. Norovirus의 검출에 영향을 주는 요인으로는 암모니아성질소, 총고형분, 과망간산칼륨 소비량으로 나타났다. Norovirus 양성 검출군과 음성 검출군의 수질특성을 비교한 결과 수소이온농도는 큰 차이가 없었고, 탁도, 암모니아성질소, 일반세균수, 총고형분 항목에 있어서 norovirus 양성 검출군 평균값이 음성 검출군 평균값 보다 높은 값을 나타내었다. Norovirus 검출과 관련성이 높은 환경인자의 지속적인 모니터링을 통해 집단 급식소 식중독예방에 기여할 수 있을 것으로 기대된다.