Rosemary the Antibacterial

Barbosa, Probst, Andrade, Alves, Albano, Cunha, Doyama, Rall, and Junior (2015) looked at bacteria that are becoming resistant such as Streptococcus pneumoniae, Escherichia coli (15 strains), Pseudomonas aeruginosa (15 strains), Staphylococcus aureus (MRSA) (15 strains of the resistant version and 16 strains of the sensitive version), Salmonella Typhimurium (15 strains) and Salmonella Enteritidis (16 isolates). 

Herbs they looked at were rosemary, Baccharvis dracuncutifolia (alecrim do campo), Vernonia polyanthes (assa peixe), Matrivaria recutita (chamomile), Cinnamomum zeylanicum (cinnamon), Caryophyllus aromaticus (clove), and Eugenia uniflora (pitanga).  All essential oils were distilled using steam. 

There is a lot of data in this study with the number of bacteria and herbs being tested.  For rosemary, the top 5 ingredients identified were camphor, limonene, myrcene, a-pinene, and b-pinene. The authors provide a chart which breaks these out for each herb tested. 

They also tested some combinations.  For the rosemary and alecrim do campo, the top 5 ingredients were limonene, merolidol, camphor, a-pinene, and myrcene. When rosemary was combined with cinnamon, the top 5 were cinnamaldehyde, camphor, limonene, myrcene, and a-pinene.  Combined with clove, the top were eugenol, camphor, ethyl eugenila, limonene, and b-caryophyllene.

Rosemary by itself took 79.35 mg/mL to be effective against all but S. aureus, MRSA, and MSSA. It was only 8.6 mg/mL these.  It took 24 hours to get a full kill ratio for E. coli and S. aureus. The combination of cinnamon and rosemary was also very effective against E. coli and rosemary combined with clove was very effective against S, aureus.

Of the plants tested, rosemary produced a larger amount of oil than most of the others. 

The authors mentioned the antimicrobial activity in the oils tested are a result of the composition of terpenes, stating most of what was extracted was a terpene or a derivative. 

NOTE: This study can be a bit confusing to read as the charts are many and the graphs were probably in color originally but are not in the paper.  Fortunately, I’m on a computer and can use the zoom feature! The rest of the herbs in this study will be broken out when I use this study in the books about each of them. 

Also, the amount needed to kill salmonella and the rest in that group explains why it performed so poorly in the study with chicken.  Putting that much rosemary on the chicken would have made it so strong, no one would have wanted to eat it because rosemary has a very powerful flavor. This rosemary is also from a different region with a different chemical compound, though it was the same species.
 
Have a Great Day!

Barbosa, L. N., Probst, I. S., Andrade, B. F. M. T., Alves, F. C. B., Albano, M., Cunha, M. L. R. S., Doyama, J. T., Rall, V. L. M., and Junior, A, F. (2015). In Vitro Antibacterial and Chemical Properties of Essential Oils Including Native, Plants from Brazil against Pathogenic and Resisant Bacteria. Journal of Oleo Science, 64(3):289-298. doi: 10.5650/jos.ess14209.