• International Journal of Oral Biology
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• 제39권3호
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• pp.137-143
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• 2014

Dental professionals are repeatedly exposed to many microorganisms present in both blood and saliva. Thus, dental professionals are at a greater risk of acquiring and spreading infections, and the implementation of infections control guidelines is necessary. Cellular phones have become a necessary device for communicating in hospitals. Cellular phones contaminated with bacteria may serve as a fomite in the transmission of pathogens by the hands of medical personnel. Nevertheless, studies about rate and levels of bacterial contamination of cellular phones have been extremely limited with regards to dental personnel. The purpose of this study was to identify bacterial flora on the cellular phones of dentists by a molecular biological method using the 16S rRNA cloning and sequencing method. We acquired total 200 clones from dentists' cell phones and identified the bacterial species. Pseudomonas (34.6%), Lactobacillus (18.5%), Azomonas (11.5%), and Janthinobacterium (6%) were the dominant genera on dentists' cell phones. The oral bacteria identified were Anaerococcus lactolyticus, Gibbsiella dentisursi, Lactobacills leiae, Streptococcus mitis, Streptococcus oligofermentans, and Streptococcus sanguinis. Pathogenic bacteria and opportunistic pathogens such as Carnobacterium funditum, Raoultella planticola, Shigella flexneri, Lactobacillus iners, Staphylococcus aureus, and Staphylococcus epidermidis were also identified.

• 환경생물
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• 제30권4호
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• pp.287-306
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• 2012

지구적으로 양서류가 감소하고 있다. 오래전부터 중금속은 양서류 군집 감소의 원인 중 한가지로 지목받고 있다. 수정 후 변태에 이르는 생활사를 수중에서 진행하는 양서류는 수환경 내의 오염물질에 1차적으로 노출되며 독성효과에 대한 감수성이 높아 수환경의 오염에 특히 취약하다. 양서류는 수서생태계의 건강도 지표로서 유용할 뿐 아니라 분자 및 개체수준의 다양한 생체지표를 이용한 다양한 환경오염물질의 독성평가 모델로서도 유용하다. 양서류에서 얻어진 독성자료는 수환경 오염물질의 관리와 안전관리기준으로 사용될 수 있다. 본 논문에서는 기존에 보고된 중금속이 양서류의 다양한 독성종말점에 미치는 영향들에 대해 검토하고 분석하였다.

• International Journal of Oral Biology
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• 제39권4호
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• pp.215-220
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• 2014

Toothbrushes play an essential role in oral hygiene. However, they can be significant in microbial transmission and can increase the risk of infection, since they can serve as a reservoir for microorganisms in healthy, oral-diseased and medically ill adults. This study was conducted to evaluate toothbrush contamination in six toothbrushes donated from four people. Two participants each supplied two toothbrushes - one used in the bathroom and one used in the workplace. The other two people each donated two toothbrushes used in the workplace. Polymerase chain reaction was used to construct a 16S rRNA clone library. Sequences of cloned DNA were compared with those from the reference organisms provided by GenBank. A total 120 clones, representing 20 clones for each toothbrush, were analyzed. They are composed of six pylum, 46 genera and 79 species. The most dominant species were Streptococcus oralis, Streptococcus parasanguinis and Haemophilus parainfluenzae. Enterobacter and Escherichia were recovered from toothbrushes used domestically. Toothbrushes used in the workplace did not contain Enterobacteria.

• 한국환경과학회지
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• 제14권1호
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• pp.23-32
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• 2005

Surface sediments (0$\~$4 cm) were sampled at 40 stations from Ulsan Bay and its adjacent areas of Korea, to evaluate the contamination by sewage-derived organic matters using fecal sterols. Some sterols were quantified by gas chromatography coupled to mass spectrometry (GC/MS). Total concentrations of eight sterols (co­prostanol, cholesterol, cholestanol, epicholestanol, epicoprostanol, ${\beta}-sitosterol,$ brassicasterol, and stigmasterol) in the sediments from Ulsan Bay and its vicinity varied from 929 to 23,444 ng/g dry weight. The most predom­inant sterols were cholesterol and coprostanol, accounting for $33\~72{\%}$ of total sterols. The concentration of coprostanol known as the indicator of human feces ranged from 141 to 8,257 ng/g dry weight. In particular, the coprostanol concentrations in the sediments from Jansaengpo Harbor and Taehwa River exceeded the value of 1,000 ng/g dry weight, suggesting that these areas could be considered as the hot-spot zones by municipal sewage contamination. Some molecular indices and multivariate data analysis were used to assess the origin of these sterols in the sediments. Results showed that the major routes of sewage contamination in Ulsan Bay and its vicinity were the input through Jansaengpo Harbor and Taehwa River.

• 한국환경과학회지
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• 제14권5호
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• pp.481-490
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• 2005

Surface sediments and seawater were sampled at Masan and Haengam Bays of Korea, to evaluate contamination by sewage-derived organic matter using fecal sterols, Six stream-water samples into Masan and Haengam Bays were also sampled. Total concentrations of eight sterols (coprostanol, epichloestanol, epicoprostanol, cholesterol, cholestanol, brassicasterol, stigmasterol and $\beta-sitosterol$) were in the range of $1,274\~4,768{\mu}g/g$ dry weight in suspended particulate from the stream-water, $292\~2,244{\mu}g/g$ dry weight in suspended particulate from the seawater and $4.5\~27.2{\mu}g/g$ dry weight in the sediments. Although sterol compositions in sediments, seawater and stream-water were different, cholesterol was the predominant sterol in all samples. The proportion and concentration of coprostanol, a sewage tracer, in stream-water was much higher than those in sediment and seawater. The sterol levels including coprostanol in the sediments and seawater were higher at inner basin than at the outer bay. Some molecular indices and multivariate statistical analysis were used to assess the origin of these sterols and sewage contamination in the study area. The sterol composition patterns in stream-water were mainly associated with contamination by sewage-derived organic matters and those of seawater were associated with the activities of marine-originated organisms. Sterol levels in the sediments were both from the sewage input through stream-water and the marine- originated organisms. This survey suggests that the main source/route of sewage-derived organic matters in Masan Bay is the input of stream-water into the bay.

• Journal of Microbiology and Biotechnology
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• 제18권11호
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• pp.1853-1857
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• 2008

Salmonella contamination in chicken meat was studied with 100 chicken meat samples purchased from 55 shops located in various regions. A total of 21 isolates of Salmonella enterica were isolated from 21 chicken meat samples from four shops located at open markets, whereas there were none from supermarkets with well-equipped cold systems. Among these, 18 isolates were identified as Salmonella enterica serotype Haardt (S. Haardt) and three isolates were S. enterica serotype Muenchen. When the minimal inhibitory concentrations of the S. Haardt isolates were assayed with the agar dilution method to determine susceptibility to ampicillin, chloramphenicol, sulfisoxazole, tetracycline, and nalidixic acid, all 18 isolates were resistant to tetracycline and nalidixic acid and nine of these were resistant to ampicillin. These isolates showed reduced susceptibility to eight fluoroquinolones including ciprofloxacin, enrofloxacin, levofloxacin, gatifloxacin, gemifloxacin, moxifloxacin, norfloxacin, and ofloxacin. When quinolone resistance determining regions of gyrA and gyrB were sequenced, every isolate had the same missense mutation Ser83$\rightarrow$Tyr (TCC$\rightarrow$+TAC) in gyrA, whereas no mutation was found in gyrB. Pulsed-field gel electrophoresis with XbaI revealed a close relationship among these isolates, suggesting a contamination of raw chicken meat with clonal spread of nalidixic acid-resistant and quinolone-reduced susceptibility S. Haardt in chickens. Results in this study show the importance of a well-equipped cold system and the prudent use of fluoroquinolone in chickens to prevent the occurrence of quinolone-resistant isolates.

• Journal of Microbiology and Biotechnology
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• 제28권11호
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• pp.1896-1907
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• 2018

Salmonellosis is commonly associated with meat and poultry products, but an increasing number of Salmonella outbreaks have been attributed to contaminated vegetables and fruits. Enteric pathogens including Salmonella enterica spp. can colonize diverse produce and persist for a long time. Considering that fresh vegetables and fruits are usually consumed raw without heat treatments, Salmonella contamination may subsequently lead to serious human infections. In order to understand the underlying mechanism of Salmonella adaptation to produce, we investigated the transcriptomics of Salmonella in contact with green vegetables, namely cabbage and napa cabbage. Interestingly, Salmonella pathogenicity island (SPI)-1 genes, which are required for Salmonella invasion into host cells, were up-regulated upon contact with vegetables, suggesting that SPI-1 may be implicated in Salmonella colonization of plant tissues as well as animal tissues. Furthermore, Salmonella transcriptomic profiling revealed several genetic loci that showed significant changes in their expression in response to vegetables and were associated with bacterial adaptation to unfavorable niches, including STM14_0818 and STM14_0817 (speF/potE), STM14_0880 (nadA), STM14_1894 to STM14_1892 (fdnGHI), STM14_2006 (ogt), STM14_2269, and STM14_2513 to STM14_2523 (cbi operon). Here, we show that nadA was required for bacterial growth under nutrient-restricted conditions, while the other genes were required for bacterial invasion into host cells. The transcriptomes of Salmonella in contact with cabbage and napa cabbage provided insights into the comprehensive bacterial transcriptional response to produce and also suggested diverse virulence determinants relevant to Salmonella survival and adaptation.

• Fisheries and Aquatic Sciences
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• 제8권3호
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• pp.167-176
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• 2005

Atmospheric deposition and riverine waters were sampled throughout a year, to estimate the loading fluxes of polycyclic aromatic hydrocarbons (PAHs) into the Masan Bay and its vicinity, Korea. Atmospheric deposition fluxes of total PAHs in the surveyed area varied from 62.2 to 464 ${\mu}g/m^2/year$. Concentration of total PAHs in water samples from six rivers ranged from 34.6 to 239 ng/L. Contribution of the carcinogenic PAHs to the total PAHs occupied $38\%$ and $50\%$ for atmospheric deposition and river waters, respectively. Atmospheric deposition fluxes and water concentrations of PAHs were slightly low or moderate to those in locations from some countries. Correspondence analysis was used to investigate the loading characteristics of PAHs according to transport routes. Atmospheric deposition samples were corresponded to higher molecular aromatics of PAHs, while riverine water samples were associated with lower molecular weight of PAHs. The results indicate that the higher-molecular-weight PAHs can be primarily transported by atmosphere deposition and the lower-molecular-weight PAHs can be mainly contaminated by riverine discharge into the Masan Bay and its vicinity. Loadings fluxes of PAHs into the Masan Bay and its vicinity were 39.2 g/day via atmosphere and 10.3 g/day via rivers, showing that atmospheric input was about 4 times higher than riverine one. Therefore, in order to minimize the contamination burden of PAHs from terrestrial sources to the Masan Bay and its vicinity, the control and management of PAHs deriving from atmosphere will be necessary.

• 생태와환경
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• 제48권2호
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• pp.86-94
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• 2015

Chironomous is aquatic insect belonging to order Diptera, family Chironomidae. Their larval stage can be found mainly in aquatic benthic environment, hence good model organism to study environmental toxicology assessments and consider as useful bio indicators of contamination of the aquatic environment. In this study, Chironomus Heat Shock Proteins, Cytochrome 450, Glutathione S-transferase, Serine-type endopeptidase gene expressions were compared between polluted field areas (Chironomus plumosus) and under laboratory conditions (Chironomus riparious) to investigate molecular indicators for environmental contaminant stress assessment. Heavy metal (Al, Fe, Mn, Cu, Cr, Zn, Se, Pb, As, Cd) concentrations in sediments collected from three study areas exceeded the reference values. Moreover, HSPs, CYP450 and GST gene expression except SP for C. plumosus showed higher expression than C. riparious gene expression. Similar gene expression pattern was observed in C. riparious that exposed environment waters up to 96 h when compared to C. plumosus exposed to waters that grown in lab conditions. In summary, this comparative gene expression analysis in Chironomous between field and laboratory condition gave useful information to select candidate molecular indicators in heavy metal contaminations in the environment.

• 한국작물학회지
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• 제54권4호
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• pp.346-350
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• 2009

The cultivated radish (Raphanus sativus L.) is a major vegetable crop in the world wide and fast-growing species that grows inhabitats of six continents. It is very important to determine hybrid seed purity in the production of hybrid Brassica vegetable seeds to avoid unacceptable contamination with self-inbred (sib) seeds. The use of random amplified polymorphic DNA (RAPD) markers for evaluating seed purity in $F_2$-hybrid radish cultivars demonstrated. One hundred eighty seeds from the F1 male and female harvest were subsequently screened for seed purity using 13 primers. The 13 primers result in 17 cultivar-specific bands and 23 variable RAPD bands scored for cultivar. RAPD analysis of hybrid seeds from the harvest revealed 128 seeds tested except underdevelopment and decayed seeds were sibs. Especially, $F_2$ hybrids of radish, OPC13, OPD20 were presented clear hybrid bands. It maintains higher than average level of genetic diversity compared with their correspondent parents. RAPD amplification of DNA extracted from germinated individuals from the female harvest reveal that 10 of 208 seeds tested were self-inbred (4.8%). RAPD analysis of hybrid seeds from the male harvest revealed 7 of the 208 seeds tested were sibs (3.4%). The RAPD may lead to a better insight in to the hybrid seed purity.