• Journal of Korean Ophthalmic Optics Society
• /
• v.19 no.1
• /
• pp.59-67
• /
• 2014

Purpose: The present study was aimed to compare the results of disinfection efficacy tested by membrane filtration method with dilution-neutralization method to develop the standard methods for evaluating disinfection efficacy of contact lens care products and to provide the result of disinfection efficacy of commercially available contact lens care products in domestic market. Methods: The results of disinfection efficacy against Staphylococcus aureus, Pseudomonas aeruginosa, Serratia marcescens, Candida albicans evaluated by membrane filtration method as a FDA standard and dilution-neutralization method as newly being a KFDA standard were compared and the disinfection efficacy of 16 multi-purpose solutions was further evaluated. Results: The disinfectants and contact lens care products having strong disinfection efficacy showed same results in both membrane filtration method and dilution-neutralization method. In case of contact lens care products having weak disinfection efficacy, the number of micro-organisms was not able to count since the colony was aggregated when evaluated by membrane filtration method. However, the number of micro-organisms was able to exactly count when evaluated by dilution-neutralization method. In addition, some commercially available contact lens care products did not meet disinfection standard and especially, their disinfection effect was often weak against Serratia marcescen and Candida albicans. Conclusions: It is concluded that dilution-neutralization method will be useful to evaluate disinfection efficacy since it is possible to count micro-organisms more precisely even with small amount of sample and check the results faster compared with membrane filtration method.

• Journal of Korean Ophthalmic Optics Society
• /
• v.20 no.1
• /
• pp.35-42
• /
• 2015

Purpose: The present study was aimed to compare the difference in adherence level of microorganisms according to contact lens materials and protein deposition and to evaluate disinfection efficacy of multipurpose solution. Methods: The evaluations of micro-organisms' adherence and disinfection efficacy of multi-purpose solution were conducted by employing the Part 2. Regimen Procedure for Disinfecting Regiments in the Disinfection Efficacy Testing under the "FDA Evaluation Criteria & Method". Results: Pseudomonas aeruginosa, Serratia marcescens, Candida albicans except Staphylococcus aureus adhered more on etafilcon A lens and disinfection efficacy of total 4 products investigated was almost perfect except Candida albicans. The 3 micro-organisms except Serratia marcescens adhered more to albumin-predeposited lens. Disinfection efficacy of multi-purpose solution was higher against the micro-organisms adhered to albumin-deposited lens than against the micro-organisms adhered to the lysozyme-deposited lens. Furthermore, disinfection efficacy of multi-purpose solution was different according to types of micro-organisms. Conclusions: It was revealed that the type of micro-organisms, the lens materials and type of absorbed tear protein affected the amount of adhered micro-organisms to contact lens and that adhesion of tear protein could induce the change of disinfection efficacy of multi-purpose solution. It suggest that the hygienic condition of contact lens can vary by these factors influencing on disinfection efficacy and the occurrence of adverse effect can be affected.

• Korean Journal of Food Science and Technology
• /
• v.37 no.5
• /
• pp.838-843
• /
• 2005

Bacterial suspension test was used to establish Standardization Test Method to investigate bactericidal activity of disinfectant/sanitizer product. Using acceptable verification methodology, test substance showing 5 log or higher reduction in viable count against Escherichia coli ATCC 10536 and Staphylococcus aureus ATCC 6538, representing Gram-negative and -positive bacteria, respectively, under test conditions for $5\;min{\pm}10\;sec\;at\;20{\pm}1^{\circ}C$ was considered to have sanitizing capability. All disinfectant/sanitizer products tested under manufacturer's recommended in-use condition gave good reduction values against major food-poisoning bacteria. This standardized method was valuable for evaluating efficacy of disinfectants/sanitizers and could be used as Standardization Test Method for assessing bactericidal activity

• Tuberculosis and Respiratory Diseases
• /
• v.53 no.5
• /
• pp.497-509
• /
• 2002

Background : The mechanisms through which cellular activation results in intracellular mycobacterial killing is only partially understood. However, in vitro studies of human immunity to Mycobacterium tuberculosis have been largely modeled on the work reported by Crowle, which is complicated by several factors. The whole blood culture is simple and allows the simultaneous analysis of the relationship between bacterial killing and the effect of effector cells and humoral factors. In this study, we attempted to determine the extent to which M. tuberculosis is killed in a human whole blood culture and to explore the role of the host and microbial factor in this process. Methods : The PPD positive subject were compared to the umbilical cord blood and patients with tuberculosis, diabetes and lung cancer. The culture is performed using heparinized whole blood diluted with a culture medium and infected with a low number of M. avium or M. tuberculosis $H_{37}Ra$ for 4 days by rotating the culture in a $37^{\circ}C$, 5% $CO_2$ incubator. In some experiments, methlprednisolone- or pentoxifyline were used to inhibit the immune response. To assess the role of the T-cell subsets, CD4+, CD8+ T-cells or both were removed from the blood using magnetic beads. The ${\Delta}$ log killing ratio was defined using a CFU assay as the difference in the log number of viable organisms in the completed culture compared to the inoculum. Results : 1. A trend was noted toward the improved killing of mycobacteria in PPD+ subjects comparing to the umbilical cord blood but there was no specific difference in the patients with tuberculosis, diabetes and lung cancer. 2. Methylprednisolone and pentoxifyline adversely affected the killing in the PPD+ subjects umbilical cord blood and patients with tuberculosis. 3. The deletion of CD4+ or CD8+ T-lymphocytes adversely affected the killing of M. avium and M. tuberculosis $H_{37}Ra$ by PPD+ subjects. Deletion of both cell types had an additive effect, particularly in M. tuberculosis $H_{37}Ra$. 4. A significantly improved mycobacterial killing was noted after chemotherapy in patients with tuberculosis and the ${\Delta}$ logKR continuously decreased in a 3 and 4 days of whole blood culture. Conclusion : The in vitro bactericidal assay by human whole blood culture model was settled using a CFU assay. However, the host immunity to M. tuberculosis was not apparent in the human whole blood culture bactericidal assay, and patients with tuberculosis showed markedly improved bacterial killing after anti-tuberculous chemotherapy compared to before. The simplicity of a whole blood culture facilitates its inclusion in a clinical trial and it may have a potential role as a surrogate marker in a TB vaccine trial.

• The Bimonthly Magazine for Agrochemicals and Plant Protection
• /
• v.2 no.11
• /
• pp.85-90
• /
• 1981

최근 농약사용에 관하여 많은 논의가 있으나 병충해방제를 전적으로 농약에 의존하는 것이나 또는 농약의 사용을 전적으로 부정하는 것 등 극한적인 평가자세는 농약에 대한 올바른 평가가 될 수 없다. 대부분의 농약은 원래 독성이 있는 것이며 또 독성이 있기 때문에 효과를 나타내는 것이다. 지금까지 경험적으로 밖에는 알지 못하였던 살균제의 작용기구 분야에도 많은 연구가 있어 점차 그 내용이 밝혀지고 있으며 이 내용을 다소나마 이해한다는 것은 살균제의 올바른 사용을 위해서도 필요하다. 본지에서는 농약 안전사용에 관련하여 살충제에이어 살균제의 사용기구와 사용시 주의점에 관해 앞으로 몇회에 걸쳐 연재할 계획이다. 관심있는 독자에게 많은 참고자료가 되기를 바란다.

• Journal of Food Hygiene and Safety
• /
• v.22 no.4
• /
• pp.235-242
• /
• 2007

This study was conducted to investigate the effect of aerosolized chemical sanitizers on inhibiting foodborne pathogens such as Escherichia coli O157:H7, Salmonella typhimurium, and Listeria monocytogenes. Five domestic commercial sanitizers subjected to five groups of sanitizer (chlorine-based, hydrogen peroxide-based, Iodophor-based, quaternary ammonium-based, and alcohol-based sanitizers) were aerosolized by an aerosol generator into a model cabinet and treated in laboratory media containing three pathogens for 1 h at room temperature. Aerosolized hydrogen peroxide-based and quaternary ammonium-based sanitizers were effective at inhibiting levels of E. coli O157:H7 (ca. 4-9 log reductions) whereas other aerosolized sanitizers such as chlorine-based, Iodophor-based, and alcohol-based sanitizers did not significantly reduced the levels of E. coli O157:H7. For S. typhimurium, the only aerosolized hydrogen peroxide-based sanitizer was effective and resulted in ca. 5-9 log reduction. Aerosolized hydrogen peroxide-based, Iodophor-based, and quaternary ammonium-based sanitizers significantly reduced levels of L. monocytogenes and especially, aerosolized quaternary ammonium-based sanitizer was strongly effective to kill L. monocytogenes, resulted in higher than 8.8 log reduction. And there was no special trend in inhibitory efficacy of sanitizers aerosolized by 1.6 or 2.4 MHz aerosol generators. From these results, aerosolization has great potential for use in commercial applications however it's efficacy could be very different depending on type of sanitizers.

• Korean journal of applied entomology
• /
• v.11 no.2
• /
• pp.109-111
• /
• 1972

The study is carried out in laboratory to investigate fungicidal activity of Dithane M-45 as a seed treatant. For use in rice seed, Dithane M-45 is more effective fungicide than organic mercuric compounds. The adequate concentration of Dithane M-45 is 1000 ppm and about 6 hours is proper duration to control seed borne pathogen on rice. Dithane M-45, however, is not good enough to control Fusarium spp. in various concentration levels.

• Journal of Food Hygiene and Safety
• /
• v.22 no.2
• /
• pp.132-136
• /
• 2007

Disinfectants/sanitizers, showing the bactericidal activity of $5log_{10}$ reduction against E. coli ATCC 10536 and Staphylococcus aureus ATCC 6538 used far assessing disinfectants/sanitizers efficacies, were examined whether showing similar efficacies against Salmonella spp. and Listeria monocytogenes, the major food poisoning bacteria, isolated from foods in current Korean market. The bactericidal efficacies on sodium hypochlorite and benzalkonium chloride were assessed by quantitative suspension tests in both 'clean' and 'dirty' conditions, respectively. Test organisms were consisted of E. coli ATCC 10536, Staphylococcus aureus ATCC 6538, Salmonella typhimurium ATCC 13311, Salmonella Enteritidis ATCC 13076, Listeria monocytogenes ATCC 19111, 10 kinds of Salmonella spp. from foods, and 11 kinds of Listeria monocytogenes from foods. More than $5log_{10}$ reduction in viable count for all strains was only achieved with benzalkonium chloride at the tolerance exemption concentration under dirty conditions. However, all strains were achieved more than $5log_{10}$ reduction under clean conditions.

• Journal of the Korean Chemical Society
• /
• v.48 no.4
• /
• pp.451-455
• /
• 2004

• Journal of the Korean Chemical Society
• /
• v.49 no.4
• /
• pp.363-369
• /
• 2005