Antibiotic sensiivity profile of enteric bacteria isolated from soil samples around Kemri (CMR) and its environs in Nairobi Kenya
Soil is able to contain enteric bacteria and other pathogens in great concentrations, as it is normally a recipient of solid and liquid waste materials frequently. Recent studies elicit that soil may have a greater role in the transmission of enteric diseases than previously expected, even though its role as a reservoir of certain bacterial pathogens is not in doubt. Enteric bacteria are responsible for causing most gastrointestinal infections, for example salmouellosis, dysentery, typhoid fever and other infections caused by Yersinia sp. and Escherichia coli 0157:H7 and many other strains. The study was aimed at determining the prevalence of enteric bacteria from various soil samples collected around Nairobi, and to compare their drug susceptibility profile with those from clinical samples. The soil samples were collected from various locations in Nairobi within a radius of 30km from Kenya Medical Research Institute, Centre for Microbiology Research in Nairobi, with their Global Position System CGPS) location recorded down, then transported to the laboratory. Ten grams of each of the soil samples were serially diluted then plated on Mueller-Hinton agar and incubated at 30ﾰC overnight, the colonies were Gram stained and the Gram-negative colonies inoculated on Analytic Profile Index kit (API 20E) for further identification. Antibiotic sensitivity testing was done using Disc Diffusion method and then compared with clinical isolates. Out of the soil samples (n=236) inoculated onto Mueller- Hinton agar, 17 were positive for Proteus salmonicida, which represents a prevalence of 7.2% of enteric bacteria in the soil. The other isolated Gram negative bacteria were Myroides spp, Pseudomonas putida, Pseudomonas aeruginosa, Stenotrophomonas maltophila and Alcaligenes spp. Proteus salmonicida showed a higher sensitivity to the antibiotics compared to the clinical Proteus except for Cefotaxime antibiotic which was resistant to it. In conclusion, soil may be a significant a reservoir for the enteric bacteria contributing to antibiotic resistance as indicated by Proteus salmonicida with resistance to Cefotaxime antibiotic, compared to Proteus species from the clinical sources which was sensitive to the same antibiotic.