Activity of Kalanchoe integra against Selected Pathogenic Bacteria

Abstract

Kalanchoe integra is a plant that belongs to the Crassulaceae family. In English, the international common name is never die. There are 1500 species of perennial herbs or low shrubs in the genus. Antibiotic resistance is currently at an alarmingly high level. Phytocompounds of Kalanchoe sp . were reported as antimicrobial agents. In Rwanda, no study about antimicrobial activity of K. integra extracts against bacteria-causing diseases was conducted. Therefore, the aim of the present study was to investigate the antimicrobial effectiveness of K. integra phytochemicals against clinically selected pathogenic bacteria ( Shigella sonnei, Haemophilus influenza, Salmonella typhi, Escherichia coli, Staphylococcus aureus and Streptococcus pneumoniae ). Maceration technique was used to prepare the leaf and stem extracts using methanol, water and petroleum ether. Phytochemical screening tests revealed that flavonoids, phenolics, and saponins were present in the leaves and stem extracts by using methanol and water. However, tannins were only present in the leaves. No phytochemicals observed by the using petroleum ether. The antimicrobial activity of clinically selected pathogenic bacteria ( S. aureus, Haemophilus influenza, Streptococcus pneumoniae, Shigella sonnei, S. typhi, and E. coli ) was tested using the agar well diffusion procedure. In order to analyse the data, SPSS was used. The means of inhibition zones of leaf and stem extracts were studied using a two-way ANOVA and both of them showed statistical significant with p-values of 0.03 and 0.04, respectively. Antibacteria activity results showed that S. typhi was more sensitive than other tested bacteria. The largest zone of inhibition (20.5 mm) was observed with methanol leaf extract against S. typhi , and the smallest inhibition was observed with H. influenza (12.5 mm). Leaf and stem extracts using methanol solvent showed activity on all bacteria used in the study except on S. sonnei . Leaf and stem water extracts significantly inhibit the growth of E. coli with inhibition zone of 14.5 mm and 11.5 mm, respectively, while petroleum ether had no effect on any bacterium. Thus, the present medicinal plant could serve as antibiotics as it showed an important activity against studied bacteria. The study has to continue with other plant parts and other bacteria-causing diseases to make the process cost-effective.