## 4 Discussion
### Antibacterial Activity  
To the best of our knowledge, the plants utilized in this research have not been previously assessed against _Staphylococcus_ spp. derived from mastitis. However, various studies have shown the antibacterial activities of extracts from these plants against _Staphylococcus_ spp. from different sources and other plants against _Staphylococcus_ spp. isolated from bovine mastitis cases. For instance, the essential oil extracted from _S. lancea_ has been reported to possess antibacterial activity against _S. aureus_, with a MIC value of 0.01 mg/mL [34], while the 70% methanol extract of the plant's leaf showed a MIC of 0.06 mg/mL [35]. Considering the MIC values obtained with the acetone extract of _S. lancen_ against isolates of _S. aureus_ in this work, together with these examples, leaf extracts of _S. lancea_ prepared using different solvents have antibacterial activities against _S. aureus_. The result obtained in this investigation using the acetone extract of _S. leptodictya_ against the ATCC strain of _S. aureus_ corresponds with another report of the same MIC value of 0.16 mg/mL against the same strain of _S. aureus_ as was found in this study [36]. Meanwhile, another study reported MIC of 0.60 mg/mL with the acetone leaf extract of _T. emetica_ against _S. aureus_[37], which is higher than the MIC values obtained against six of the _S. aureus_ strains used in this study with the same extract. A striking observation from Tables 5 and 6 is that only the acetone extract of _S. lancea_ showed good activity against all the strains of _S. aureus_ and NAS. Neither the ethanol extract of _S. lancea_ nor both (acetone and ethanol) extracts of other plants had good activity against any strain of NAS. The results also suggest that the _S. aureus_ strains were more susceptible to the extracts than the NAS strains. A similar pattern of susceptibility was reported by other researchers [38], although they used a disc diffusion method. Significant antibacterial properties against mastitis-causing bacteria were observed with all the extracts obtained from _Liquidambar orientalis_ leaf using three different solvents (acetone, methanol, and ethanol). However, the antibacterial activity of these extracts was significantly poorer against NAS species than against _S. aureus_. The acetone extracts showed the highest antibacterial activity (with a 12 mm inhibition zone diameter) against _S. aureus_ 17, while the lowest antibacterial activity (with a 7 mm inhibition zone diameter) of acetone extracts was found against NAS-36 [38]. Another study reported varying susceptibility patterns regarding the essential oils obtained from selected plants [38]. They reported that some isolates of NAS (S.  
epidermidis_ and _S. xylosus_) (MIC = 0.156%) appeared to be less susceptible than some isolates of _S. aureus_ to the essential oil of _Pelargonium gravelens_ (MIC = 0.078%). Furthermore, they also reported some isolates of both _S. aureus_ and NAS that were susceptible at the same concentration to essential oils of other plants, such as _Juniperus virginiana_ (MIC = 0.010%), _Leptospermum scorarium_ (MIC = 0.005%), _Pogostemom cablin_ (MIC = 0.010%), and _Thymus vulgaris_ (MIC = 0.010%) [39]. In another study, it was reported that the acetone leaf extract of _Acacia nilotica_ showed higher antibacterial activity against _S. epidermidis_ and _S. chromogenes_ (MIC = 0.156 mg/mL) than _S. aureus_ (MIC = 0.625 mg/mL) [40]. This same pattern was also reported [39], claiming that some isolates of NAS (MIC = 0.020%) appeared to be more susceptible than some isolates of _S. aureus_ (MIC = 0.156%) to the essential oil of _Cinnamom cassia_. The acetone leaf extract of _Aloe arborescens_ showed a similar MIC (>2.5 mg/mL) against _S. aureus_ and _S. chromogenes_, and a lower MIC (2.5 mg/mL) against _S. epidermidis_[40]. Further research needs to be conducted to unravel the reason for these patterns.