Background:
This study aimed at the identification of the Salmonella serovars involved in human salmonellosis outbreaks in Saudi Arabia, determination of their susceptibility to drugs, and determination of Minimum Inhibitory Concentration (MIC) of an essential oil-blend of eucalyptus and peppermint.
Material and Methods:
The identification of the O and H antigens of the Salmonella serovars was according to WHO protocol, while their susceptibility to active ingredients of 23 drugs was accomplished by single disk diffusion assay. The MIC was determined by a standard protocol, while the safety of the blend was assessed by Draize Eye and Ames tests.
Results:
The distribution of the 16 separately admitted Saudi patients, due to their infection with different Salmonella serovars were: 4 (S.enteritidis), 4 (S.typhimurium), 3 (S.kentucky), 3 (S.anatum), and 2 (S.typhi). The three in vitro effective drugs against all 14 non-typhoid isolates were Cefepime, Chloramphenicol, and Norfloxacin, while 10 drugs were effective against S.typhi isolates. A positive correlation (R=??) between the frequency of drugs that the Salmonella isolates were resistant to and the MIC of the essential oil-blend was observed (P<0.05). The essential oil blend was found to be safe for use.
Conclusion:
Only three drugs out of 23 were effective in vitro against the Non-Typhoids, while 10 drugs were fortunately effective against the Typhoids. The safety and MIC data related to the novel blend of the essential oils encourage to pursue its efficacy in vivo to help for future use against Salmonella infections.