title: In vitro antibacterial activity of MGDG-palmitoyl from Oscillatoria acuminata NTAPC05 against extended-spectrum β-lactamase producers.
abstract: Extended-spectrum β-lactamase (ESBL)-producing bacteria pose a big challenge in clinical practices, warranting a new therapeutic strategy. In this study, methanol extract of the marine cyanobacterium Oscillatoria acuminata NTAPC05 was fractionated under bioassay guidance and the fractions were tested against three well-characterized ESBL-producing bacteria Escherichia coli U655, Stenotrophomonas maltophilia B929 and Enterobacter asburiae B938. Out of the four HPLC fractions, fraction 2 showed bactericidal activity against all the three ESBL producers much more efficiently (MIC 100 μg ml-1) than the fourth-generation cephalosporin (MIC >125 μg ml-1). The active fraction was subjected to time-kill test at concentrations of 1/2 × MIC, 1 × MIC and 2 × MIC, and the results substantiated the bactericidal property of the fraction against the ESBL producers. Spectral analysis revealed monogalactosyldiacylglycerol containing a palmitoyl (MGDG-palmitoyl), being reported for the first time, as the active fraction, and its bactericidal property against ESBL producers was determined. The active fraction appears to damage the bacterial membrane leading to lysis of the cell, as revealed in confocal laser scanning microscopy (CLSM) analysis, that was confirmed in scanning electron microscopic analysis. Cytotoxicity assay revealed the O. acuminata compound to be safe to a normal cell line HEK293 (human embryonic kidney cell). The in silico analysis of MGDG-palmitoyl revealed two successive H-bonding interactions with Leu198 of TEM1 β-lactamase. Taken together, the MGDG-palmitoyl from O. acuminata NTAPC05 offers potential to develop analogs as a therapeutic for bacteremia caused by ESBL producers.
authors.affiliation: Division of Microbial Biodiversity and Bioenergy, Department of Microbiology, Bharathidasan University, Tiruchirappalli, India.
authors.forename: Abdul Azees
authors.initials: AA
authors.lastname: Parveez Ahamed
authors.affiliation: Centre for Biotechnology and Bioinformatics, Jawaharlal Nehru Institute of Advanced Studies, Secunderabad, India.
authors.forename: Mohammed Uddin
authors.initials: MU
authors.lastname: Rasheed
authors.affiliation: Department of Biomedical Science, Bharathidasan University, Tiruchirappalli, India.
authors.forename: Kalilurrahuman
authors.initials: K
authors.lastname: Peer Muhamed Noorani
authors.affiliation: Division of Microbial Biodiversity and Bioenergy, Department of Microbiology, Bharathidasan University, Tiruchirappalli, India.|P.G. and Research Department of Microbiology, Jamal Mohamed College (Autonomous), Tiruchirappalli, India.
authors.forename: Nazar
authors.initials: N
authors.lastname: Reehana
authors.affiliation: Department of Botany, Government Arts College (Autonomous), Karur, India.
authors.forename: Subramanian
authors.initials: S
authors.lastname: Santhoshkumar
authors.affiliation: Division of Microbial Biodiversity and Bioenergy, Department of Microbiology, Bharathidasan University, Tiruchirappalli, India.
authors.forename: Yousuff Mohamed
authors.initials: YM
authors.lastname: Mohamed Imran
authors.affiliation: Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia.
authors.forename: Naiyf S
authors.initials: NS
authors.lastname: Alharbi
authors.affiliation: Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia.
authors.forename: Chinnathambi
authors.initials: C
authors.lastname: Arunachalam
authors.affiliation: Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia.
authors.forename: Sulaiman Ali
authors.initials: SA
authors.lastname: Alharbi
authors.affiliation: National Centre for Alternatives to Animal Experiments, Bharathidasan University, Tiruchirappalli, India.
authors.forename: Mohammad Abdulkader
authors.initials: MA
authors.lastname: Akbarsha
authors.affiliation: Division of Microbial Biodiversity and Bioenergy, Department of Microbiology, Bharathidasan University, Tiruchirappalli, India.|Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia.|National Centre for Alternatives to Animal Experiments, Bharathidasan University, Tiruchirappalli, India.
authors.forename: Nooruddin
authors.initials: N
authors.lastname: Thajuddin
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D002511:Cephalosporins / Q000494:pharmacology; D003198:Computer Simulation; D004754:Enterobacter / Q000187:drug effects*; D004926:Escherichia coli / Q000187:drug effects*; D038983:Galactolipids / Q000737:chemistry; D057809:HEK293 Cells; D006801:Humans; D008826:Microbial Sensitivity Tests; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D054300:Oscillatoria / Q000378:metabolism*; D020615:Stenotrophomonas maltophilia / Q000187:drug effects*; D001618:beta-Lactamases / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D038983:Galactolipids; C009909:monogalactosyldiacylglycerol; D001618:beta-Lactamases