In Vitro Investigation of the Effects of Certain Antibiotics and Plant Oils on the Clinical Isolates of Streptococcus pneumoniae

With the serial trend toward antibiotic resistance in Streptococcus pneumoniae, novel drug development is needed to deal with pathogenic microorganisms that have developed widespread microbial resistance to antibiotics.

Eighty-seven clinical samples were collected from six hospitals in Damascus. A polymerase chain reaction (PCR) was performed to identify the bacterial genus and type. Minimum inhibitory concentrations on Luria-Bertani agar were conducted using several antibiotics and essential oils (EOs).

Twenty-five isolates of S. pneumoniae were found, and amoxicillin and cephalosporins were the most effective antibiotics against 90% of S. pneumoniae bacteria. On the other hand, Thymus syriacus Boiss., Origanum syriacum L., Rosmarinus officinalis L., Cinnamomum zeylanicum L., and Juniperus foetidissima Willd were the most effective EOs.

Only T. syriacus Boiss., O. syriacum L., R. officinalis L., C. zeylanicum L., and J. foetidissima Willd oils had good inhibitory effects against S. pneumoniae.