Bacteriostatic or bactericidal action of four aqueous plant extracts on multi-drug resistant bacteremia and their effect on cells morphology recorded using scanning electron microscopy (SEM)

Four aqueous traditional plant extracts from rosemary leaves (Rosmarinus officinalis), clove buds (Syzygium aromaticum [L.] Merr at Perry, Myrtaceae), cinnamon bark (Cinnamomum zeylanicum) and ginger rhizomes (Zingiber officinale) were tested as natural antibiotics against multi-drug resistant bacteremia isolates: Six Gram negative isolates, viz. Acinetobacter baumanni/haemolyticus, Citrobacter freundii, Escherichia coli, E. coli ESβL, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella sp. and four Gram positive isolates viz. methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus epidermidis, Streptococcus pneumoniae and Bacillus sp. were which used to test antibiotic activity. The usage of clove extract (25X) appeared to have maximum antibacterial activity against all tested Gram negative bacteria, when compared with other tested plant extracts at the same concentration. In the case of G+ve bacteria, tested extracts appeared to have almost the same efficiency. Swabs were taken from inhibition zone resulting from the inhibitory effect of aqueous extracts towards the tested isolates and re-inoculated to detect either the bacteriostatic or bactericidal action. Again, clove extract exhibited the highest effect when compared with other tested against the isolates from bloodstream. Scanning electron microscopy was used to record external morphological changes of the bacterial cells such as appendages, shortness and lyses.