BackgroundGroup B Streptococcus (GBS) is a harmless commensal bacterium in healthy adults but it causes sepsis in neonates resulting in a high rate of mortality. This study was carried out to investigate the antibacterial activity of Bryophyllum pinnatum and Rauvol a vomitoria bioactive fractions on thirty-ve multidrug resistant Group B Streptococcus (GBS) strains implicated on neonatal sepsis as well as to identify the antibiotic resistant genes present. The phytochemical analyses were carried out using column chromatography. Antibacterial activity, Minimum Inhibitory Concentration (MIC) and Minimum Bacteria Concentration (MBC) of the different plant biofractions was determined using disc diffusion technique. The presence of erythromycin (ermB) and tetracycline (tetO) resistant genes was identi ed using duplex PCR techniques. Graphing was done using Graph pad prism (version 5.0a).
ResultThe results obtained from this study show that the selected plants have dose dependent activity against GBS. Ethanol biofraction of R. vomitoria had the highest activity with an MIC value ranges between 12.5 mg/ml and 50 mg/ml and MBC ranges from 25 mg/ml and 50 mg/ml followed by methanol biofraction of B. pinnatum with an MIC value ranging between 50mg/ml and 100mg/ml on 32 out of the 35 strains investigated, leaving the other three having MIC values of 25 mg/ml then MBC values ranging between 50 mg/ml and 100mg/ml while N-hexane and aqueous biofractions had the least activity. Also, the presence of ermB and tetO resistant genes were present in all the ten representative GBS strains tested.
ConclusionThe high rate of activity shown by the methanol and ethanol extracts of both plants suggests that the plants can serve as a potential alternative for the treatment of neonatal sepsis. However, a further study on their in vivo activity is important in order to evaluate the e ciency, safety and potential adverse effects and drug herb interactions of the plants.