ANTIBACTERIAL ACTIVITY OF SELECTED MEDICINAL PLANT EXTRACTS AGAINST ESCHERICHIACOLI STRAINS ISOLATED FROM DIARRHOEIC STOOL OF CHILDREN IN NIGER STATE, NIGERIA
ANTIBACTERIAL ACTIVITY OF SELECTED MEDICINAL PLANT EXTRACTS AGAINST ESCHERICHIACOLI STRAINS ISOLATED FROM DIARRHOEIC STOOL OF CHILDREN IN NIGER STATE, NIGERIA
No Thumbnail Available
Date
2021-04
Authors
MUHAMMAD, Isah Legbo
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
The study was carried out to determine the antibacterial activity of Entadaafricana,
Ptericarpuserinaceus and Vitexdoniana extracts against Escherichia coli strains isolated from
diarrhoeic stool of patients (0-5) years attending selected Hospitals in Niger State, Nigeria. The
Hospitals include UmaruSanda General Hospital, Bida; General Hospital, Minna and General
Hospital, Kontagora. A total of 480 stool samples were collected from diarrhoeal patients
between February and October, 2014. The samples were cultured on MacConkey agar and Eosin
Methylene Blue agar. The isolates obtained were Gram-stained, identified and serotyped using
biochemical tests and Escherichia coliidentification strain kits. The phytochemical screening of
Entadaafricana, Ptericarpuserinaceusand Vitexdoniana leaf and stem-bark extracts was
evaluated using standard qualitative methods. Acute toxicity (LD50) was determined using oral
administration method. The antibacterial activity of Entadaafricana, Ptericarpuserinaceusand
Vitexdonianaleaf and stem-bark extracts were also evaluated using agar well diffusion method.
The minimum inhibitory and minimum bactericidal concentration was evaluated using broth tube
dilution and pour plating methods respectively. The work established a value of 16.9% of
diarrhoeagenic Escherichia coli in the study area. Different strains of Escherichia coli associated
with diarrhoeal patients that were isolated include Enteroaggregative Escherichia coli (n=16,
19.8%), Enterohaemorrhagic Escherichia coli (n=13, 16.1%), Enteroinvasive Escherichia coli
(n=8, 9.9%), EnteropathogenicEscherichia coli (n=27, 33.3%) and EnterotoxigenicEscherichia
coli (n= 17, 21.0%). Socio-demographic and risk factors found to be associated with diarrhoea in
the study area were: age, area of domicile, occupation, educational status of parents, source of
water and feeding pattern were statistically significant. The phytochemical screening of all the
crude extracts were found to have anthraquinones, flavonoids, glycosides,saponins, steroids,
tannins and resins except forPtericarpus erinaceousin which resins was not detected. The acute
toxicity (LD50) of thethree plant extracts against albino rats wasgreater than5000mg/kg body
weight could be safe for use in human or higher animals. The methanolic extracts
ofEntadaafricana, Ptericarpuserinaceus and Vitexdoniana showed highest activity against
Escherichia coli at 20mg/mL with zones of inhibition ranging between 20.00-36.00mm, 20.00-
30.00mm and 24.00-38.00mm respectively.The methanolic leaf fraction of Vitexdonianahad the
highest activity against all the testedEscherichia coli strain except Enteroinvasive Escherichia
coli which had 50% susceptibility. The Vitexdoniana aqueous stem-bark fraction with minimum
inhibitory concentration (MIC) and minimum bactericidal concentration(MBC) values of 5.0 and
10.0mg/mL emerged as the active fraction against 75% of the EAEC, while methanolic leaf
fraction had MIC and MBC values of 5.0 and 10mg/mL against 77% of the EHEC. The aqueous
leaf fraction had MIC and MBC values of 10mg/mL against 62.5% of the EIEC, while
methanolic leaf fraction had MIC and MBC values of 5.0 and 10mg/mL against 61% and 81% of
the EPEC. The methanolic stem-bark fraction exhibited highest activity with MIC and MBC
values of 5.0 and 10mg/mL against 79% and 100% of the EnterotoxigenicEscherichia coli.The
extracts of the plants could be promoted for search of new leads against enterobacterial
pathogens having MIC values of 5.0-20mg/mL. The result has justified their utilization by
traditional medicine practitioners for the treatment of diarrhoea and other related ailments
associated with Escherichia coli strains.
Description
A DISSERTATION SUBMITTED TO THE SCHOOL OF POSTGRADUATE
STUDIES, AHMADU BELLO UNIVERSITY, ZARIA IN PARTIAL FULFILLMENT OF THE
REQUIREMENTS FOR THE AWARD OF THE DOCTOR OF PHILOSOPHY (Ph.D)
DEGREE IN MICROBIOLOGY
DEPARTMENT OF MICROBIOLOGY,
FACULTY OF LIFE SCIENCES,
AHMADU BELLO UNIVERSITY,
ZARIA
Keywords
ANTIBACTERIAL ACTIVITY,, SELECTED MEDICINAL PLANT,, ESCHERICHIACOLI STRAINS ISOLATED,, DIARRHOEIC STOOL,, CHILDREN,, NIGER STATE,, NIGERIA