Abstract

The aim of this research was to investigate the antibacterial activity of the ethanolic bark extract of Syzygium cumini
on Escherichia coli recovered from surface waters used in Ishaka municipality. The study involved the collection of
surface water samples and the isolation of E. coli strains from these samples. Antibiotic susceptibility testing was
performed using the Kirby-Bauer disc diffusion method on (ciprofloxacin, amoxicillin, ceftriaxone, and gentamicin)
while the resistance and intermediate isolate were subjected to the antibacterial effect of ethanolic bark extract of
Syzygium cumini. The antibacterial activity of the S. cumini bark extract was evaluated using the disc diffusion method
and the zone of inhibition was measured. The results showed that the surface waters sampled had a high total
bacterial count, indicating potential contamination. The E. coli isolates were found to have varying levels of
sensitivity and resistance to the antibiotics tested, with ciprofloxacin and amoxicillin showing the highest resistance
rates. The S. cumini bark extract demonstrated good antibacterial activity against some E. coli strains, particularly
BI1 and RI1, but was less effective against LI1, LI4, and rl1. Overall, the study suggests that the ethanolic S. cumini
bark extract has potential as an alternative or complementary antibacterial agent against E. coli in surface waters,
but further investigation is required to fully assess its efficacy and safety.