Isolation, identification and sensitivity testing of Microorganisms from stool received from patients at Kenyatta National Hospital

Abstract

The aim of this project was to isolate microorganisms from stools of patients from Kenyatta National Hospital, to identify them using various microbiological techniques and finally their sensitivity against commonly used therapeutic agents. The antibiotics used included:-

(1) Ampicillin 25 microgramme (2) Tetracycline 25 microgramme (3) Trimethoprim/Sulphamethaxazole 25 microgramme (4) Streptomycin 10 microgramme (5) Kanamycin 30 microgramme (6) Gentamicin 10 microgramme (7) Polymixin B Sulphate 250 units (8) Neomycin 30 microgramme Stool samples were plated on the Mac Conkey’s Agar and colonies obtained were identified using Gram stain method, Motility and subculturing on TSI (Triple Sugar Iron). Finally sensitivity testing was done with the antibiotic discs on Mac Conkey's. From the results obtained, it was found that:- (1) The organisms isolated were E. coli, Salmonella and Shigella. (2) In majority of the patients (16 out of 24), the causative organism was E. coli, (3) All the microorganisms were most sensitive to Gentamicin. E. coli was least sensitive to Tetracycline while Salmonella and Shigella were not sensitive at all to Ampicillin, Tetracycline, Trimethoprim/Sulphamethoxazole and Streptomycin.