Phenotypic And Genotypic Characteristics Of Foodborne Bacteria Associated With Biofilm Formation In Fresh Ulam

Abstract

Ulam are important food among the Malays because of their nutritional values, and their consumption is increasing. However, the foodborne outbreak which is associated with eating raw ulam may pose health risks to the consumers by increasing crosscontamination, antibiotic-resistant bacteria and biofilm formation. The objectives of

this

study were to determine the phenotypic characterisation and genotypic identification of E. coli and Salmonella isolated from ulam and their association with biofilm. A total of 32 samples of ulam were randomly collected from wet markets and supermarkets in Kuala Terengganu. The microbiological study was done to enumerate microbial counts and to isolate E. coli and Salmonella using biochemical tests and API20E kit. They were further assessed for phenotypic characteristics such as antibiotic susceptibility testing, colony morphology and biofilm formation. Polymerase chain reaction (PCR) was performed to determine the genotypic identification associated with tetracycline resistance and biofilm formation in E. coli and Salmonella isolates. The microbiological quality of ulam samples were in the range of 6.36-8.83; 4.14-7.48; 0-8.16; 3.94-6.45 log10 CFU/g for aerobic mesophilic bacteria, coliforms, Salmonella and yeast and moulds, respectively. E. coli and Salmonella were detected in 31.3% and 9.4% of ulam samples, respectively. All of the selected isolates were confirmed as E. coli and Salmonella enterica based on the molecular identification using the 16S rRNA and invA gene, respectively. Overall, it was found that the E. coli isolates were highly resistant to cephalothin (78.3%), followed by ampicillin (52.2%), tetracycline (52.2%) and streptomycin (30.4%).