Antibacterial activity of plant essential oils against indigenously characterized methicillin-resistant Staphylococcus aureus (MRSA)

@#Plant essential oils were evaluated for antimicrobial activity against Methicillin-resistant Staphylococcus aureus (MRSA). The isolates (n=03) were procured from Institute of Microbiology, UVAS Lahore, Pakistan. After biochemical and 16S rRNA gene-based PCR characterization, accession numbers were retrieved from NCBI i.e. MW344063.1, MW344064.1 and MW344065.1. These isolates exhibited molecular positivity by multiplex PCR for mecA, coa and eta toxin genes. Moreover, these isolates exhibited resistance to cefoxitin, ampicillin, amoxicillin, penicillin, amoxicillin clavulanate, ciprofloxacin, erythromycin and gentamicin. The antibiotic resistant isolates were evaluated for antimicrobial activity of plant essential oils. The highest zone of inhibition (mean ZOI±S.D.) was measured for Cinnamomum verum (22.67±1.52 mm) followed by Eucalyptus globulus (18.67±2.51 mm) and Syzygium aromaticum (12.67±2.51 mm). Lowest mean MIC value (0.33±0.11 mg/mL) was recorded for E. globulus. Eucalyptus globulus was processed for fractionation by column chromatography and n-hexane, chloroform, n-hexane + chloroform and ethyl-acetate fractions were evaluated for antibacterial activity. Lowest mean MIC (10.04±5.80 mg/mL) was recorded for E. globulus n-hexane fraction. Cell survival percentage of BHK21 cell line was 51.7% at 54.87mg/mL concentration of E. globulus n-hexane fraction. Through gas chromatography-mass spectrometry (GC-MS) analysis of n-hexane fraction, benzene was found abundant (29.9%) as active compound. It was concluded that E. globulus n-hexane fraction exhibited significantly promising results against MRSA.

Antibacterial activity of the essential oils from the leaves of Eucalyptus globulus against Escherichia coli and Staphylococcus aureus

<p><b>OBJECTIVE</b>To examine the in vitro antimicrobial activities of essential oil of the leaves of Eucalyptus globulus (E. globulus).</p><p><b>METHODS</b>The essential oils of this plant were obtained by the hydrodistillation method. The inhibitory effects of this essential oil were tested against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) by using agar disc diffusion and dilution broth methods.</p><p><b>RESULTS</b>The results obtained showed that essential oil of the leaves of E. globulus has antimicrobial activity against gram negative bacteria (E. coli) as well as gram positive bacteria (S. aureus).</p><p><b>CONCLUSION</b>The encouraging results indicate the essential oil of E. globulus leaves might be exploited as natural antibiotic for the treatment of several infectious diseases caused by these two germs, and could be useful in understanding the relations between traditional cures and current medicines.</p>

Rapid and undamage determination of fruit of Eucalyptus globules labill by near infrared spectroscopy and clustering analysis / 中成药

AIM: To provide a rapid method for identifying fruit of Eucalyptus globule labill. METHODS: A new method, using NIRS for rapid and nondestructive classfication of the fruit of Eucalyptus globules labill and its counterfeit drug, the fruit of Eucalyptus robusta Smith, was proposed and then cluster analysis was adopted. RESULTS: The result showed that two kinds of fruits had their own characteristic NIRS spectra. CONCLUSION: The method is quick, simple and reliable, and in combination of the fingerprint NIRS spectrum and the clustering analysis is easy to identify the adulteration.