Potential Alternative Treatment of Ocular Bacterial Infections by Oil Derived from Syzygium aromaticum Flower (Clove)

ABSTRACT

Purpose/Aim: This study aims to evaluate the predisposing risk factors and antibiotic resistance of bacterial corneal ulcer to commonly used antibiotics. In addition, assess the in vitro efficacy of plant-derived essential oils (EOs) as safe and effective antimicrobial agents.

Methods: Demographic features and predisposing risk factors of corneal ulcer patients were recorded. Isolation and identification of bacteria was performed using conventional microbiological methods. Antibacterial activity was determined by disk diffusion and the micro-dilution broth methods. EOs were extracted by steam distillation and were analyzed by gas chromatography mass spectrometry technique.

Results: Out of the 200 patients with corneal ulcer evaluated in this study, the main predisposing factor of bacterial corneal ulcer was trauma (26.5%) and 96.7% isolates were multidrug resistant. Staphylococcus aureus was the predominant isolate 33 cases. Antibiotic susceptibility of bacterial isolates showed that the fourth-generation fluoroquinolones, gatifloxacin was the most effective antibiotic with sensitivity rate 81.3%. Seven selected EOs showed significant activity against most of the tested bacteria. Syzygium aromaticum oil showed high activity against all tested bacterial species with highest sensitivity rate (97.5%) and low minimal inhibitory concentration values against S. aureus (0.10 µl/ml). The chemical composition of the EOs showed that the monoterpenes were predominant. The main constituent of S. aromaticum oil was eugenol (76%).

Conclusions: The current study showed that S. aromaticum oil had high antibacterial activity that could be helpful in the treatment of ocular bacterial infections to minimizing the possible side effects of commonly used antibiotic.

KEYWORDS:

• Multidrug-resistant bacteria
• Staphylococcus aureus
• predisposing factors
• antimicrobial resistance
• bacterial keratitis

Acknowledgments

The authors thank Prof. Hasnaa Hosny (Cairo University, Giza, Egypt) for the taxonomic identification of all plant materials. Many thanks to the staffs of the Clinic Corneal Unit, Ophthalmology Hospital (Giza, Egypt) for their technical support.

Declaration of interest

No potential conflict of interest was reported by the authors. The authors alone are responsible for the content and writing of the paper.

Ethical approval

According to the Egyptian regulation on observational and/or retrospective database analyses, the study did not require the approval of any ethics committee.

Additional information

Funding

None

Notes on contributors

Mahmoud S. M. Mohamed

All authors involved in the conception of the research idea, methodology design, in particular MSMM and AAA. Both AAA and MSMM carried out the laboratory work. MHM identified the bacterial strains. AAA and MSMM interpreted the results and prepared the manuscript for publication. MHM, MSMM, and AMS reviewed the manuscript. All authors read and approved the final manuscript.