• Fibers and Polymers
• /
• v.7 no.1
• /
• pp.8-11
• /
• 2006

It has been reported for several decades that microbes, which naturally contaminate cotton fibres during crop growth and subsequent storage can have an adverse effect on the structural quality of cotton lint. Although several studies have analysed the relationship between numbers of Gram-negative bacteria or bacterial endotoxin and particular physical properties, these studies have been limited to cotton from the United States, and the possible effects of fungal contamination have not been examined in detail. This study quantified the Gram-negative bacteria and fungal cells, as well as measuring concentrations of bacterial endotoxin and fungal glucan, on cotton lint samples from international sources. Spearman's rank correlation coefficients calculated between these results and quality data analysed by an automated testing instrument revealed several significant correlations. Findings included inverse correlations between the biological contamination parameters and fibre elongation, micronaire and reflectance. The possible causes and implications of these findings were also discussed.

• Journal of Microbiology and Biotechnology
• /
• v.25 no.4
• /
• pp.554-558
• /
• 2015

Drug delivery systems (DDSs) incorporating bacterial minicells have been evaluated as a very powerful tool in view of biocompatibility. However, limited studies have been carried out on these systems, mainly using minicells from Salmonella sp. and Escherichia coli. Thus, we generated a new minicell-producing strain from an endotoxin-free Corynebacterium glutamicum by the inactivation of genes related to cell division. The two knockout strains, ${\Delta}parA$ and ${\Delta}ncgl1366$, showed distinct abilities to produce minicells. The resulting minicells were purified via sequential antibiotic treatments and centrifugations, which resulted in reproducible yields.

• Journal of Microbiology and Biotechnology
• /
• v.31 no.1
• /
• pp.25-32
• /
• 2021

Inflammatory reactions activated by lipopolysaccharide (LPS) of gram-negative bacteria can lead to severe septic shock. With the recent emergence of multidrug-resistant gram-negative bacteria and a lack of efficient ways to treat resulting infections, there is a need to develop novel anti-endotoxin agents. Antimicrobial peptides have been noticed as potential therapeutic molecules for bacterial infection and as candidates for new antibiotic drugs. We previously designed the 9-meric antimicrobial peptide Pro9-3 and it showed high antimicrobial activity against gram-negative bacteria. Here, to further examine its potency as an anti-endotoxin agent, we examined the anti-endotoxin activities of Pro9-3 and elucidated its mechanism of action. We performed a dye-leakage experiment and BODIPY-TR cadaverine and limulus amebocyte lysate assays for Pro9-3 as well as its lysine-substituted analogue and their enantiomers. The results confirmed that Pro9-3 targets the bacterial membrane and the arginine residues play key roles in its antimicrobial activity. Pro9-3 showed excellent LPS-neutralizing activity and LPS-binding properties, which were superior to those of other peptides. Saturation transfer difference-nuclear magnetic resonance experiments to explore the interaction between LPS and Pro9-3 revealed that Trp3 and Tlr7 in Pro9-3 are critical for attracting Pro9-3 to the LPS in the gram-negative bacterial membrane. Moreover, the anti-septic effect of Pro9-3 in vivo was investigated using an LPS-induced endotoxemia mouse model, demonstrating its dual activities: antibacterial activity against gram-negative bacteria and immunosuppressive effect preventing LPS-induced endotoxemia. Collectively, these results confirmed the therapeutic potential of Pro9-3 against infection of gram-negative bacteria.

• Proceedings of the Korean Environmental Health Society Conference
• /
• 2003.06a
• /
• pp.132-135
• /
• 2003

Endotoxin concentrations were measured from 69 point-of-use(POU) water treatment system(WTS) by using Limulus amebocyte lysate(LAL) assay, and the results were compared to heterotrophic bacterial data. Endotoxin concentrations in all POU WTS water samples and tap waters varied within the range 0.8-79.1EU mL$\^$-1/ and 0.1-3.4EU mL$\^$-1/, respectively, The correlations between endotoxin concentration and HPC bacteria from the water samples showed not significant(r=0.18).

• Journal of Microbiology and Biotechnology
• /
• v.13 no.3
• /
• pp.444-450
• /
• 2003

In order to develop an effective means to treat P. aeruginosa infections, we have purified P. aeruginosa outer membrane proteins (OMPs)-specific human IgG antibody. In this study, we investigated the protective activity of the purified anti-OMPs IgC against P. aeruginosa infection in a rabbit endophthalmitis model. Rabbits were inoculated by an intravitreal injection with P. aeruginosa, and treated with a single dose of 1 mg anti-P. aeruginosa OMPs IgG. All the control rabbits predominantly developed edematous responses and opacity in the eyes, but the rabbits treated with the antibody showed only very limited degree of edema. Aliquots of the vitreous humor were extracted and analyzed for the number of viable bacteria and endotoxin level. The results showed that the anti-OMPs IgC significantly reduced the bacterial count compared with the control group, and that the endotoxin level of the vitreous from the IgG-treated rabbits was more than 70-fold lower 6 h after the administration than the control animals. These data suggested that the anti-P. aeruginosa OMPs IgG is effective in inhibiting the bacterial growth and thereby in reducing endotoxin levels in the vitreous, warranting further development of the anti-P. aeruginosa OMPs IgG as a therapeutic means for treating Pseudomonas endophthalmitis.

• Korean Journal of Clinical Laboratory Science
• /
• v.48 no.2
• /
• pp.124-129
• /
• 2016

Endotoxin, also known as lipopolysaccharide (LPS) produced by the cell wall of gram negative bacteria can be present in any liquid or on any biomaterial. Endotoxin in blood can cause fever and inflammation. In this study, we compared bacterial endotoxin using Escherichia coli O157:H7, Klebsiella oxytoca, Salmonella Typhi, Shigella sonnei and Morganella morganii. Bacteria were cultured for use in the experiment, and diluted to $1.5{\times}10^8CFU/mL$. A check marked sensitivity confirmatory test of the Limulus amebocyte lysate (LAL) reagent was performed to examine the validity. The end point reaction to each bacteria sample was confirmed with 10 fold dilution and then the final reaction end point was confirmed by 2 fold dilution between the dilution step and the upper dilution step. According to the results, in detection of endotoxins in more than 0.015 EU/mL, E. coli O157 was 75~37.5 CFU/mL, K. oxytoca 37.5~18.75 CFU/mL, M. morganii and S. Typhi 3.75~1.875 CFU/mL, and S. sonnei 7.5~3.75 CFU/mL. The resulting value was finally ensured by a confirmation test for the inhibitory factor. Based on this study, conduct of further research on bacterial endotoxin is encouraged.

• Journal of Food Hygiene and Safety
• /
• v.15 no.1
• /
• pp.30-35
• /
• 2000

To investigate the effects of bacterial endotoxin on lipids and cytokines, and to explain the relationships between their changes, we carried out this study using experi-mentally Escherichia coli (E. coli) endotoxin-induced septicemic rabbits. The triglyceride and cholesterol concentrations in endotoxin groups were generally high (p<0.01 or 0.05) at all sampling time points (from 3hr to 24 hr), while phospholipid concentrations in endotoxin groups elevated in dose-dependent fashion at 3hr and 6hr after endotoxin injection compared to control group (p<0.05), There were significant negative correlations between lipids changes and cytokines (TNF-$\alpha$ and IL-1$\beta$) each other (p<0.05), and endotoxic rabbits having higher triglyceride of cholesterol levels shown relatively better conditions compared with others. As a result, the alterations in the lipid compositions caused by endotoxin may imply an active exhibition of the host defense mechanism rather than the disturbances of lipid metabolism.

• Toxicological Research
• /
• v.16 no.1
• /
• pp.39-45
• /
• 2000

This study was carried out to evaluate antitoxic effects Palsun Brewing Water against cadmium by colorimetric methods. The antitoxic activity of Palsun Brewing Water in NIH-3T3 fibroblasts was evaluated by MTT ({3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazoliumbromide} and SRB (sulforhodamine B protein) assays. The light microcopic study was carried out to observe morphological changes of the treated cells. These results were obtained as follows: The concentration of 10-2 mg/ml of Palsun Brewing Water was shown significant antitoxic activity against E. coli endotoxin and Salmonella endotoxin. The number of NIH-3T3 fibroblasts were antitoxin and tend to regenerate. These results suggest that Palsun Brewing Water retains a potential antitoxic activity.

• Journal of Periodontal and Implant Science
• /
• v.22 no.2
• /
• pp.211.1-211.1
• /
• 1992

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.20 no.4
• /
• pp.274-281
• /
• 2010

The objectives of this study are (a) to investigate the distribution patterns and exposure concentrations of biological agents in sawmill industries and (b) to compare sampling methods of biological agents. The representative processes of 5 sawmills were selected to measure total airborne bacteria, fungi, endotoxin as well as dust. Airborne bacteria and fungi were measured with one stage impactor, six stage impactor and gelatin filteration methods. Endotoxin was collected with polycarbonate filters and analysed by kinetic chromogenic Limulus Amebocyte Lysate method. Geometric mean levels of airborne bacteria, fungi, endotoxin and dust were 1,864 CFU/$m^3$, 2,252 CFU/$m^3$, 31.5 EU/$m^3$ and 2.4 mg/$m^3$. The ratios of indoor/outdoor concentrations were 3.7 for bacteria, 4.1 for fungi, 3.3 for endotoxin and 9.7 for dust. The respiratory fractions of bacteria were 68.0, 50.9, 49.2 and 45.1% in band-saw, table-saw, rip-saw process and outdoor air. The respiratory fractions of fungi were 78.7, 90.8, 87.5 and 84.8% in band-saw, table-saw, rip-saw process and outdoor air, respectively. There was no significant differences in bacterial concentrations among single stage, six stage impaction and filteration methods. But, fungal concentrations measured with filtration methods were significantly higher than those with impaction methods. Geometric mean levels of airborne bacteria and fungi were higher than the OSHA guideline values of 1,000 CFU/$m^3$. The respiratory fractions of fungi were above 75%. The concentrations of biological agents were significantly different among culture-based sampling methods. In the exposure assessments of biological agents, further studies are needed for the comparisons of diverse sampling methods and the investigations of environmental factors.