The cold water extract of the fruit pulp was active against all (100%) of the non
diarrheagenic bacterial strains tested achieving inhibition zone diameters (IZDs)
ranging from 18 ± 0.0 mm to 24.5 ± 0.71 mm and minimum bactericidal
concentration (MBC) of 125 mg/mL (Tables 3 and 4); but both the hot water and
ethanolic extracts were active against 6 (85.71%) each. Similarly, both ethanolic
extracts of the leaves and stem bark showed activity against 5 (71.43%) of the non
diarrheagenic bacterial strains each whilst the cold water extract of leaves, stem
bark and hot water extract of the stem bark each showed activity against 28.57%,
respectively. The fruit pulp extracts were active against all five Gram positive test
bacterial strains with MBC values of 125–250 mg/mL; but the ethanolic extracts of
the stem bark (SET) and leaves (LET) showed activity against 80% each (Table 3).
Seven (7) local clinical isolates of E. coli from infantile diarrhea (numbered 1–7)
and 3 of Pseudomonas aeruginosa (numbered 1 and 2, respectively) including one
found to be multiple drug resistant (coded MDR) were specifically tested with SET
and all the fruit pulp extracts and the results are shown in Table 5. With the
exception of one isolate, E. coli 2, which showed no susceptibility to all the
extracts tested and E. coli 4, which was not affected by FET, the local isolates
including the multiple drug resistant P. aeruginosa were susceptible with IZD
range of 10.50 ± 0.00 mm to 28.00 ± 0.00 mm. Figures 1 and 2 shows the dose
response curves of T. indica fruit pulp extract tested in vitro against representatives
of Gram negative and Gram positive bacterial strains, respectively. The result
showed that the IZD increased directly with the concentrations of the extracts used
irrespective of the solvent used for extraction.