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Effect of Azadirachtin on Bacterial Biofilm Formation
Author(s) -
Kaverimanian Vishnu,
Heuertz Rita
Publication year - 2019
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2019.33.1_supplement.650.6
Subject(s) - biofilm , azadirachta , azadirachtin , bacteria , antibiotics , microbiology and biotechnology , staphylococcus aureus , phytochemical , antibiotic resistance , chemistry , biology , traditional medicine , medicine , pesticide , genetics , agronomy
Due to the overuse of currently available antibiotics, bacteria are rapidly evolving resistance to modern medical treatments. Because of this fact, it is important to find alternative antimicrobic agents for which bacteria have not yet developed resistance. To compound this problem, it has been identified that bacteria living in biofilms (as aggregates protected by extracellular polymeric matrix) can be up to 1000 times more antibiotic‐resistant than their planktonic counterparts. The NIH has reported that up to 80% of chronic and 65% of all human infections are biofilm‐associated. One major therapeutic alternative to modern antibiotics is phytochemicals (plant‐derived compounds). A phytochemical of interest, azadirachtin, is derived from the neem tree ( Azadirachta indica ) which has been historically used in the Indian subcontinent as an herbal remedy for many ailments including those caused by parasites and bacteria. A significant source of infection in hospitals is Staphylococcus aureus which is known for emerging antimicrobic resistance and tendency to form biofilms. The purpose of my project was to identify if azadirachtin inhibits biofilm formation. In order to determine the effects of azadirachtin on biofilm, a microplate biofilm quantitative assay was performed. S. aureus that were methicillin resistant (MRSA, 4 different strains) or susceptible (MSSA, 3 different strains) were assessed. Bacteria were first inoculated into tryptic soy broth (TSB) and incubated (37°C, overnight). Afterwards, bacteria were standardized to a spectrophotometric A590 of 0.1–0.2 growth. Once standardized, the bacteria were transferred to 96‐well microplates with/without azadirachtin (0–0.8 mM) and incubated (37°C, 20 h). Following incubation, bacteria were killed with glutaraldehyde and microplates were washed (three times with dH 2 O). Subsequently, crystal violet (0.1% aqueous) was added to stain the biofilm. Excess dye was removed by washing (three times with dH 2 O) and stained biofilm was solubilized (8% acetic acid). Solubilized biofilm was quantitated by A590 readings. Results indicated that azadirachtin had no significant (p<0.05) effect on mean biofilm amounts for MRSA and MSSA biofilm formation. As azadirachtin appears to elicit no anti‐biofilm effect on the Gram positive S. aureus , our next step will be to ascertain its effect on Gram negative Pseudomonas aeruginosa biofilm. Support or Funding Information Financial support for VK was received from the DeNardo Education and Research Foundation. This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .