Evaluation of the Antimicrobial Effect of Annona Muricata on Diarrhoea Causing Bacteria Isolated from Stool Samples of Primary School Children in Nnewi North

ABSTRACT
Soursop (Annona muricata) has stood out as an efficient plant in folklore medicine used in the
therapeutic management of various ailments. The aim of this study is to isolate bacteria causing
diarrhoea from school children and evaluate the anti-microbial susceptibility effect of Annona
muricata leaf extract on the isolates. Fresh tender leaves of this plant were collected, air dried,
powdered and percolated in methanol solvent. Isolation, Biochemical and Morphological
characteristics of the isolates were done using a standard procedure. Qualitative and Quantitative
phytochemical analysis were done using different methods. The antimicrobial activities of the
extracts against test organisms were tested using agar well diffusion method and the MIC and
MBC were determined by agar dilution assay. Quantitative phytochemical analysis confirmed
the presence of various phytochemicals like Tannin, Alkaloid, Flavonoid, etc. The isolates from
stool samples subcultured yielded salmonella typhi and shigella dysenteriae. The antimicrobial
test of the extracts on the isolates revealed that the extract had a zone of inhibition of 9.67± 0.47
against the salmonella typhi and 11.83± 0.14 for shigella dysenteriae, whereas ciprofloxacin had
32.25±0.93 zone of inhibition for salmonella typhi and 25.50±1.02 for shigella dysenteriae. The
methanol extract had MIC and MBC of 50 mg/ml and 40 mg/ml for salmonella typhi and
shigella dysenteriae respectively. Ciprofloxacin had MIC and MBC of 20 mg/ml against
salmonella typhi and MIC and MBC of 30mg/ml against shigella dysenteriae. Annona muricata
as an alternative to treating bacteria causing diarrheoa will help to reduce antimicrobial
resistance in drugs and increase drug efficiency