| Research Title |
In vitro activities of the secreted substance fromenvironmental Klebsiella pneumoniae strain against 11 clinical Pythium
insidiosum isolates |
| Date of Distribution |
5 June 2018 |
| Conference |
| Title of the Conference |
20th Congress of the International Society for Human and Animal Mycology |
| Organiser |
Congress Care |
| Conference Place |
Amsterdam RAI, the Netherlands |
| Province/State |
Amsterdam |
| Conference Date |
30 June 2018 |
| To |
4 July 2018 |
| Proceeding Paper |
| Volume |
56 |
| Issue |
2 |
| Page |
S144 Medical |
| Editors/edition/publisher |
Karl V. Clemons |
| Abstract |
Objective: To investigate the in vitro activities of crude extract from Klebsiella pneumoniae ST2501 and their fractions against
11 clinical Pythium insidiosum isolates by using different end point methods: disc diffusion assay and broth dilution minimal cidal
concentration (MCC) assay.
Methods: In our previous study, crude extract from K. pneumoniae ST2501, the bacterial isolated from environmental
sources shown promising results in antifungal activities against P. insidiosum. Crude ethyl acetate extract from fluid secretion
cell-free filtrates of K. pneumoniae ST2501 was separated by column chromatography and subsequently eluted with a gradient of
two solvents (dichloromethane and methanol) by gradually increasing the polarity of the elution solvent system. The eluents were
collected and monitored by thin layer chromatography, producing five groups of eluting fractions. The antifungal activity of all
fractions against the mycelia form of 11 clinical P. insidiosum isolates were evaluated using disc diffusion assay (0.5 mg/μl; 20
μl/disc). The fraction which shown strong activity was evaluated by using broth dilution minimal cidal concentration (MCC) at
the final concentrations ranging from 0.870 to 3.132 mg/ml. Mycelia fragments of 5 mm in diameter of 11 clinical isolates of P.
insidiodum were incubated with the fraction which shown strong activity and evaluated for up to seven days to detect the MCC.
The experiment was repeated four times.
Results: The antimicrobial activities of crude extract and five fractions from K. pneumoniae ST2501 against 11 clinical isolates
of P. insidiosum were evaluated by using disc diffusion assay. Crude extract and fraction No. 1 demonstrated strong activity by give
the inhibition of 100% of mycelium growth. Fractions No. 1 which eluted by 100% dichloromethane were evaluated antimicrobial
activity against 11 clinical isolates of P. insidiosum by using broth dilution MCC assays. Seven out of 11 P. insidiosum isolates were
inhibited at 1.566 mg/mL (63.6%); three isolates were inhibited at 1.74 mg/mL (27.3%) while only one isolate was inhibited at
1.914 mg/mL (9.1%).
Conclusion: These results suggest that new compounds with potential therapeutic activity against pythiosis may come from
microorganism or nature. However, further in vivo studies are needed to validate our findings as well as the acute toxicity testing in
animal models and fraction No. 1 might be purification in the near future. |
| Author |
|
| Peer Review Status |
มีผู้ประเมินอิสระ |
| Level of Conference |
นานาชาติ |
| Type of Proceeding |
Abstract |
| Type of Presentation |
Poster |
| Part of thesis |
true |
| Presentation awarding |
false |
| Attach file |
|
| Citation |
0
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Publication
Journal Publication
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