Effects of Piper cubeba L. essential oil on methicillin-resistant Staphylococcus aureus: an AFM and TEM study.
The increasing prevalence of antibiotic-resistant bacteria is creating a real challenge for health care systems worldwide, making the development of novel antibiotics a necessity. In addition to the development of new antibiotics, there is an urgent need for in-depth characterization of the mechanisms of bacterial resistance toward new drugs. Here, we used essential oils extracted in our laboratory from Piper cubeba against methicillin-resistant Staphylococcus aureus ATCC 43300, one of the most prominent antibiotic-resistant bacteria. Effects of the essential oils extracted from P cubeba on bacteria were mainly evaluated using 2 powerful microscopy techniques: atomic force microscopy and transmission electron microscopy. High-resolution atomic force microscopy images of the cells were obtained close to their native environment by immobilizing the cells on porous Polyether sulfone membranes, which were prepared in our laboratory with a wide range and distribution of pore sizes and depth. Inhibition zones (mm) and minimum inhibitory concentrations were determined. Two different concentrations of the oil were used to treat the cells: 50 μg/mL minimum inhibitory concentration and 25 μg/mL. The 50 μg/mL oil solution caused severe damage to the bacterial cells at microscopic levels while the 25 μg/mL solution showed no effects compared to the control. However, at nanoscopic levels, the 25 μg/mL oil solution caused significant changes in the cell wall, which could potentially impair bacterial activities. These results were also confirmed by transmission electron microscopy micrographs. Our results indicate that the extract has a good biological activity against methicillin- and oxacillin-resistant S aureus and that it acts on the cell wall and plasma (cytoplasmic) membrane.
Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, KSA, 11451, Saudi Arabia.
Naiyf S
NS
Alharbi
Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, KSA, 11451, Saudi Arabia.|Department of Biotechnology and Food Technology, Thamar University, Dhamar, Yemen.
Jamal M
JM
Khaled
Department of Physics and Astronomy, King Saud University, Riyadh, KSA, 11451, Saudi Arabia.|King Abdullah Institute for Nanotechnology, King Saud University, Riyadh, KSA, 11451, Saudi Arabia.
Khalid E
KE
Alzaharni
Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, KSA, 11451, Saudi Arabia.
Ramzi A
RA
Mothana
Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, KSA, 11451, Saudi Arabia.
Mansour S
MS
Alsaid
King Abdullah Institute for Nanotechnology, King Saud University, Riyadh, KSA, 11451, Saudi Arabia.|Department of Chemical Engineering, King Saud University, Riyadh, KSA, 11451, Saudi Arabia.
Mansour
M
Alhoshan
King Abdullah Institute for Nanotechnology, King Saud University, Riyadh, KSA, 11451, Saudi Arabia.
Lawrence Arockiasamy
LA
Dass
Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, KSA, 11451, Saudi Arabia.
Shine
S
Kadaikunnan
Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, KSA, 11451, Saudi Arabia.
Ahmed S
AS
Alobaidi
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000648:ultrastructure; D008826:Microbial Sensitivity Tests; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D009822:Oils, Volatile / Q000494:pharmacology*; D031701:Piper / Q000737:chemistry*; D010938:Plant Oils / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D009822:Oils, Volatile; D010938:Plant Oils
AFM; MRSA; Piper cubeba; Staphylococcus aureus; TEM