DOI: 10.36347/sajb.2016.v04i01.007

Pages: 38-44

This study was conducted to compare the microbial load of used plastic and wood chopping board samples and to determine the presence of Salmonella sp. and other Enterobacteriaceae species from the samples. Plate counts on Nutrient Agar and Mc Conkey agar were conducted to determine total microbial load and number of presumptive Salmonella colonies, respectively. Cultural characterization of isolates was done based from the 8th Edition of Bergey’s Manual for Determinative Bacteriology. Identification of Salmonella sp. and other Enterobacteriaceae was done using standard microbiological techniques involving the use of selective and differential media. Gram staining was performed to confirm morphological characteristics of isolates. Results of the study revealed that used plastic chopping boards have a significantly higher total microbial load than wood chopping boards with a mean of 1.41x107 and 1.28x107, respectively. The number of presumptive Salmonella sp. was also significantly higher in plastic chopping boards than wood chopping boards with a mean of 4.25x106 and 1.6x104, respectively. Colonies isolated from both chopping boards showed various cultural characteristics, such as size, pigmentation, form, margin and elevation. Successive confirmatory biochemical tests on presumptive Salmonella sp. isolates confirmed the presence of Salmonella sp. and other Enterobacteriaceae sp. such as Enterobacter, Klebsiella, Escherichia, Citrobacter, Arizona and Proteus. The presence of rod-shaped and pinkish cells from Gram-stained isolates reveals the Gram-negative bacteria and further confirms the presence of Salmonella sp. and other Enterobacteriaceae sp.