Background: Diarrhea is a major health concern in Namibia with an estimate of 17000 cases in 2015 in Omusati and Kunene
regions. The present study aimed at isolating and identifying gastrointestinal bacteria from stool samples of children admitted
at Katutura hospital, Windhoek, and to determine the efficacy of selected medicinal plants used in treating gastroenteritis in
Namibia.
Materials and Methods: Stool samples were collected for 6 months from children under age five admitted with acute
diarrhea. Seeplex12 automated DNA extractor and PCR were used for isolation and identification of bacterial DNA from the
samples. Serially diluted stool samples were cultured on selective media, sub-cultured in Nutrient broth and preserved in 80%
glycerol. Parts of
Boscia albitrunca
,
Ziziphus mucronata
,
Combretum apiculatum
,
Solanum linnaeanum
and
Terminalia sericea
were collected, dried, ground and extracted using distilled water and ethanol. Disc diffusion method was used to
determine the antibacterial activity of the plant extracts against isolated bacteria.
Results: A total of 12 out of the 18 stool samples collected had bacterial pathogens successfully identified by PCR. 33.3%
were positive for
Salmonella
, 11.1% for
E. coli
157:H7 VTEC and 22.2% for
E.coli H7.
C. apiculatum organic extracts
exhibited potent antibacterial activity of (16± 0.57mm) at 1000 μg/ml against
Shigella
and
Salmonella with a moderate
minimum inhibitory concentration (MIC) of 250 μg/ml against
Salmonella.
Salmonella and
Shigella showed resistance to 10
μg/ml of ampicillin.
Conclusion: Plant extracts showed
in vitro antibacterial activity. However, toxicology and
in vivo efficacy of these plant
extracts should be determined before recommending their mainstream uses.
