• 한국수산과학회지
• /
• 제56권1호
• /
• pp.99-108
• /
• 2023

In this study, changes in biofloc-related and pathogenic bacteria in both low and high concentration biofloc breeding water planted with the halophyte (Triglochin maritimum were investigated). In the low-concentration biofloc breeding water, the ratio of bacteria related to the nitrogen cycle was initially 59.57% and, it decreased to 26.57% at the end of the experiment while other bacteria (excluding nitrogen-cycling bacteria and vibrios) increased from 38.75% to 73.43%. However, the planted experimental group maintained a relatively high ratio of nitrogen cycling bacteria at 58%. In the high-concentration experimental group, bacteria related to the initial nitrogen cycle, non-pathogenic vibrios, and pathogenic vibrios were 11.60, 36.28, and 20.14%, respectively. Finally, nitrogen-cycling bacteria were 36.47% in the control group and 37.55% in the planted group. The total number of vibrios decreased by 46.54% in the planted group and 48.01% in the control group, indicating a significant decrease in both experimental groups. However, the residual rate of pathogenic vibrios was 4.48% in the control group and 0.54% in the planted group. Overall, the planted group showed decreasing harmful bacteria and increasing useful bacteria.

• 한국치위생학회지
• /
• 제4권2호
• /
• pp.255-263
• /
• 2004

One of the best way to prevent dental caries and periodontal disease is removing dental plaque. Toothbrushing is also one of the crucial ways to gel rid of dental plaque and improve dental hygiene. The purpose of th is study was to examine how many bacteria were attached to toothbrushes used by dental palque acidogenecity and related behaviors to toothbrush use. Subjects in this study were 30 college students in their twenties, on whom a survey was conducted to find out how they cleansed their toothbrushes, how long they cleaned toothbrushes after brushing, and how to keep them. And then dental palque acidogenecity by caries activity test was implemented and the number of bacteria attached to their toothbrushes was tested. The findings of the study were as follows : 1. Concerning correlations between dental palque acidogenecity and the number of remaining bacteria in the toothbrushes used by students, the number of bacteria was lower in the group of students with no caries activity than in the group with mild caries activity. 2. As for relations between the way of cleansing toothbrushes and the number of bacteria, there was no statistically significant gap between the group of students who wetted their toothbrushes with water and rubbed the heads of them and the group of students who just only wetted their toothbrushes with no further actions. 3. Regarding the relationship of toothbrush cleansing time to the number of bacteria, the number of bacteria was lower in the group of students who cleansed their toothbrushes for 15 seconds or more. 4. As to the influence of the number of toothbrush used by students, there was no significant difference between the group using just one toothbrush and the other group using two or more toothbrushes. 5. As for correlations between the way of keeping toothbrushes and the number of bacteria, no significant gap existed between the group thai kept their toothbrushes separately and the other that didn't.

• Reproductive and Developmental Biology
• /
• 제34권4호
• /
• pp.299-304
• /
• 2010

To identify the treatment effect of lactic acid bacteria for diabetes, the treatment effects of a single administration of acarbose (a diabetes treatment drug) or lactic acid bacteria, and the mixture of acarbose and lactic acid bacteria on diabetes in a type 1 diabetes animal model, were studied. In this study, streptozotocin was inoculated into a Sprague-Dawley rat to induce diabetes, and sham control (Sham), diabetic control (STZ), STZ and composition with live cell, STZ and composition with heat killed cell, STZ and composition with drugs (acarbose) were orally administered. Then the treatment effect on diabetes was observed by measuring the body weight, blood glucose, and serum lipid. For the histopathological examination of the pancreas, the Langerhans islet of the pancreas was observed using hematoxylin and eosin staining, and the renal cortex, outer medullar, and inner medullar were also observed. The induced diabetes decreased the body weight, and the fasting blood glucose level decreased in the lactic-acid-bacteria-administered group and the mixture-administered group. In addition, the probiotic resulted in the greatest decrease in the serum cholesterol level, which is closely related to diabetes. Also, the hematoxylin and eosin staining of the Langerhans islet showed that the reduction in the size of the Langerhans islet slowed in the lactic-acid-bacteria-administered group. The histopathological examination confirmed that the symptoms of diabetic nephropathy decreased in the group to which viable bacteria and acarbose were administered, unlike in the group to which dead bacteria was administered. The mixture of lactic acid bacteria and acarbose and the single administration of lactic acid bacteria or acarbose had treatment effects on the size of the Langerhans islet and of the kidney histopathology. Thus, it is believed that lactic acid bacteria have treatment effects on diabetes and can be used as supplements for the treatment of diabetes.

• 미생물학회지
• /
• 제36권3호
• /
• pp.167-172
• /
• 2000

제주도의 여섯 지역과 인천 작약도 근해의 해수로부터 내염성 그람양성 세균 25균주를 분리하여 화학 분류학적 특징과 표현형적 특성을 조사하였다. 분리된 균주들은 화학 분류학적 특징에 의거하여 4개의 group으로 구분되었다. Group1은 40.~49.9 mol% 의 G+C함량과 MK-7의 menaquinome type, peptidoglycan의 주요 아미노산으로 meso-A2pm을 함유하며 Bacillus pumilus와 Bacillus licheniformis, Bacillu megaterium, bacillus subtilis로 동정되었으며, Group 2는 63.9~66.4 mol% 의 G+C 함량과 MK-8을 함유하는 Arthrobacter속 세균이었으며 , Group 3은 31.0~37.6 mol%의 G+G 함량과 MK-7을 함유하며 Staphylococcus haemolyticus, Staphylococcus saprophyticyus, Staphylococcus intermedius 로 , Group 4는 72.0 mol% 의 G+C 함량과 MK-8을 주요 quinone으로 함유하는 Micrococcus luteus로 동정되었다. 분리된 세균들 중 Bacillus 속 세균들은 68%로 우세한 분포를 나타내었다.

• 미생물학회지
• /
• 제38권3호
• /
• pp.192-197
• /
• 2002

러시아 바이칼호에서 해빙기에 부유세균과 aggregates에 부착한 세균의 군집구조를 FISH (fluorescent in situ hybridization)방법으로 0 m부터 250 m수심에서 비교 분석하였다. 조사대상은 Eubacteria에 속하는 세균과 class Proteobacteria에 속하는 세균 중 $\alpha$-, $\beta$-, $\gamma$ -group과 Cytophaga-Flavobacterium group,그리고 Planctomycetales였다. 부유세균의 수는 $0.2{\times}10^6\cells{\cdot}ml^-1 to 3.2{\times}10^6 \cells{\cdot}ml^-1$범위였으며, 수심이 깊어질수록 감소하였다. Aggregate에 부착한 세균은 부유세균과 반대로 수심이 깊어질수록 증가하였고, 개체수의 범위는 0.4~$3.3{\times}10^4$ $cells{\cdot}ml^-1$ 이였다. 총세균수에 대한 Eubacteria 수의 비율은 부유세균의 경우 52.3~74.1%, aggregates에 부착한 세균은 39.6~66.7%로 부유세균보다 부착세균에서 그 비율이 낮았으며, 세균의 군집구조 분석 결과에서도 부유세균과 aggregates애 부착한 세균의 군집구조가 다른 양상으로 나타났다. 특히 두 세균의 군집구조는 식물플랑크톤이 밀집해 있는 25 m 수심에서 급격히 변화하여 식물플랑크톤이 부유세균과 부착세균의 군집의 변화에 밀접한 관련이 있는 것으로 확인되었다, Aggregates에 부착한 세균 군집은 수심에 따라 매우 특이한 변화 양상을 나타내었다. $\beta$-proteobacteria group은 수심이 깊어지면서 그 비율이 높아져, 100m에서는 $\beta$-group이 총세균수는 51.8%를 차지하였으나, 250m에서는 $\gamma$-group이 43.8%를 차지하여, 급격하게 우점 group이 변화하였다. 그러나, 부유세균에서는 전혀 다른 군집 구조를 이루고 있었다. 이러한 결과에서 aggregates에 부착한 세균은 부유세균과는 다른 다양성을 이루고, 다른 천이과정을 거치는 것으로 확인되었다.

• 미생물학회지
• /
• 제20권3호
• /
• pp.113-118
• /
• 1982

The distribution and annual variation of detergent-degrading bacteria which were isolated from the Han River downstream running through the center of Seoul area were studied. The concentration of dissolved detergent was the lowest, 2.16 ppm at site 1 and it was gradually increased to downstream, the highest, 2.67 ppm at site 4. Population density of detergent degrading bacteria was about $10^2{\sim}10^3 cells/ml$. The density of LAS degrading bacteria was 1.1 - 1.8 times larger than that of SDBS-degrading bacteria. In annual variation the lowest density was appeared on January and the highest on July. In seasonal distribution of LAS-degrading bacteria, annual dominant group was genus Pseudomonas. There were few except genus Pseudomonas in winter and the subdomiannt group in spring and summer was genus Aeromonas and Enterobacteriaceae respectively. In autumn genus Pseudomonas, Aeromonas and Enterobacteriaceae were equally distributed. In SDBS-degrading bacteria, the annual dominant group was also genus Pseudomonas.

• Toxicological Research
• /
• 제29권2호
• /
• pp.129-135
• /
• 2013

Salmonella is one of the major pathogenic bacteria that cause food poisoning. This study investigated whether heat-killed as well as live Lactobacillus protects host animal against Salmonella infection. Live and heat-killed Lactobacillusacidophilus was administered orally to Sprague-Dawley rats for 2 weeks before the rats were inoculated with Salmonella. Rise in body temperature was moderate in the group that was treated with heat-killed bacteria as compared to the Salmonella control group. The mean amount of feed intake and water consumption of each rat in the heat-killed bacteria group were nearly normal. The number of fecal Salmonellae was comparable between the live and the heat-killed L. acidophilus groups. This finding shows that L. acidophilus facilitates the excretion of Salmonella. Moreover, the levels of pro inflammatory cytokines, including tumor necrosis factor (TNF)-alpha and interleukin (IL)-1 beta, in the heat-killed L. acidophilus group were significantly lower when compared to the levels in the Salmonella control group. These results indicate that nonviable lactic acid bacteria also could play an important role in preventing infections by enteric pathogens such as Salmonella.

• 한국치위생학회지
• /
• 제15권4호
• /
• pp.713-718
• /
• 2015

Objectives: The purpose of the study was to investigate the bacterial morphology attached on ultrasonic scaler tips using no cleansing solution, alcohol cotton, liquid chemical disinfecting agent, and autoclave method. Methods: Scaling tip was applied to the mouth and the ultrasonic scaler tips were assigned to four groups. Group 1 was control group with no cleansing solution. Group 2 was treated with alcohol cotton. Group 3 was treated with 2% green Y-Na solution in liquid chemical disinfecting agent, and Group 4 was sterilized by autoclave method. Live bacteria were observed by phase contrast microscopy. The scanning electron microscopy(SEM) revealed the morphological characteristics of scaler surface. The type of attached bacteria were analyzed using SPSS 21.0 program. The data were analyzed by one-way analysis of variance(ANOVA) and Tukey's post-hoc test. Results: The types of sterilization methods had influences on the bacterial viability. The numbers of cocci, bacilli, spiral form bacteria, and filamentous bacteria was observed in $89.00{\pm}3.60%$, $29.67{\pm}3.51%$, $3.33{\pm}0.57%$ and $1.67{\pm}0.57%$ in control group, $31.67{\pm}3.51%$, $63.33{\pm}4.04%$, $2.00{\pm}1.00%$ and $1.67{\pm}0.57%$ in alcohol cotton group, $69.67{\pm}4.50%$, $12.33{\pm}2.51%$, 0% and 0% in liquid chemical disinfecting agent group, and 0.0%, 0.0%, 0.0% and 0.0% in autoclave method group. The clean surface of ultrasonic scaler tip was shown on SEM by autoclave method. Conclusions: The most effective sterilization method of ultrasonic scaler tip was the autoclave method. Autoclave method is the most effective sterilization method and can reduce the cross-infection in the dental clinic.

• 한국치위생학회지
• /
• 제14권4호
• /
• pp.593-599
• /
• 2014

Objectives : Latex gloves hygiene is the most effective method to prevent infection of microorganisms and to reduce the incidence of cross infections. The aim of this study was to compare the bacteria reduction ratio of cleansing with water, liquid soap and alcohol gauze. Methods : The left side glove was the control group and the right side was the experimental group. The experimental group washed hand with water, soap, and alcohol gauze. The hand plate was inoculated by the hand and inoculated for 24 hours in $35^{\circ}C$. Results : Washing with water showed that CFU of control group was 1116.9 and that of experimental group was 302.8. Hand washing by water reduced 74.3% of bacteria. Liquid soap revealed that CFU of control group was 619.9 and that of experimental group was 8.3. Hand washing by liquid soap reduced 97.5% of bacteria. Alcohol gauze included 875.2 CFU in control group and 5.8 CFU in experimental group. Washing by alcohol gauze reduced 99.5% of bacteria. Conclusions : Based on the results, the most effective latex gloves cleansing method was recommended as the standardized hand washing with the liquid hand soap and alcohol gauze. The results can be used to improve training strategies for enhancing glove hygiene practice in dental clinic.

• Journal of Microbiology and Biotechnology
• /
• 제17권7호
• /
• pp.1177-1182
• /
• 2007

Bacillus cereus group bacteria share a significant degree of genetic similarity. Thus, to differentiate and identify the Bacillus cereus group efficiently, a multiplex PCR method using the gyrB and groEL genes as diagnostic markers is suggested for simultaneous detection. The assay yielded a 400 bp amplicon for the groEL gene from all the B. cereus group bacteria, and a 253 bp amplicon from B. anthracis, 475 bp amplicon from B. cereus, 299 bp amplicon from B. thuringiensis, and 604 bp amplicon from B. mycoides for the gyrB gene. No nonspecific amplicons were observed with the DNA from 29 other pathogenic bacteria. The specificity and sensitivity of the B. cereus group identification using this multiplex PCR assay were evaluated with different kinds of food samples. In conclusion, the proposed multiplex PCR is a reliable, simple, rapid, and efficient method for the simultaneous identification of B. cereus group bacteria from food samples in a single tube.