an investigation into the antibacterial activities of medicinal plants ...

mg/ml (acetone extract) against K. pneumoniae strains [no.’s 1] and 1.09 mg/ml
(methanol extract) against different strains, respectively (Table 9b).
Table 10, Fig 10 & 11 displays the highest and lowest MIC values for each plant
extract against all the Gram-positive and Gram-negative bacterial strains. The
undiluted plant extract concentrations were also included as a representation of the
starting point of each extract and for comparison of the different MIC’s (Table 10).
The lowest MIC’s of B. frutescens for the Gram-positive bacterial strains were 0.13
mg/ml in the acetone extract and 0.05 mg/ml in the aqueous extract for Gramnegative
bacterial strains. The highest MIC of B. frutescens for the Gram-positive
bacterial strains was 0.43 mg/ml (aqueous extract), while the undiluted extract
concentration of 0.51 mg/ml (acetone and methanol extracts) was the maximum MIC
for the Gram-negative bacterial strains.
The lowest MIC’s of L. leonurus for Gram-positive and Gram-negative bacterial
strains were 0.07 mg/ml (methanol extract) and 0.02 mg/ml (aqueous and acetone
extracts), respectively. The undiluted aqueous extract of 1.19 mg/ml was the highest
MIC for both Gram-positive and Gram-negative bacterial strains.
The MIC’s of 0.03 mg/ml (aqueous extract) and 0.03 mg/ml (methanol extract) were
the lowest MIC values of M. major against the Gram-positive and Gram-negative
bacterial strains, respectively (Fig. 10). The highest MIC values of M. major against
the Gram-positive and Gram-negative bacterial strains were 0.21 mg/ml (aqueous
extract) and 2.17 mg/ml (acetone extract), respectively (Table 10 & Fig. 11).
The aqueous extract of Z. aethiopica displayed the lowest MIC’s of 0.01 mg/ml
(aqueous extract) against Gram-positive bacterial strains and 0.03 mg/ml (acetone
extract) against Gram-negative bacterial strains (Fig. 10). The highest MIC’s of Z.
aethiopica against Gram-positive bacterial strains were 1.00 mg/ml in the acetone
extract and 1.09 mg/ml (methanol extract) against the Gram-negative bacterial
strains (Fig. 11).
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