Antimicrobial Resistance Profiling of Non-pathogenic Microbial Flora in Curcuma longa

Due to poor hygiene and negligence of food safety standards, microbes find their way into the food supply chain by contaminating food ingredients and causing food-borne illnesses. Turmeric is not only a widely consumed spice but also a product that undergoes multiple stages of handling, from cultivation to packaging. These stages expose it to contamination risks, especially by non-pathogenic bacteria that may carry resistance genes. The study aims to bridge the gap in understanding the microbial burden in turmeric and the prevalence of AMR in its microbial communities. In this study, we investigated microbial burden in turmeric samples. Bacteria were isolated from loose and packaged turmeric samples and characterized for antimicrobial resistance, growth pattern, biochemical properties and later identified to assess potential risks to food safety. Out of 22 loose samples of turmeric, 82% had colony forming unit (CFU) >108, while most of the packed turmeric samples (98%) had CFU <108. From these samples, 13 distinct non-pathogenic bacteria associated with antimicrobial resistance (AMR) were isolated, out of which eleven were non-spore-forming bacteria. The bacterial isolates Stutzerimonas sp., Enterobacter sp., and Pantoea sp. exhibited resistant activity against clindamycin (macrolide), gentamycin (aminoglycoside), spectinomycin (aminocyclitol) and ampicillin (penicillin) with optimum growth at 45 °C and positive alkaline phosphatase (ALP) activity. This study clearly suggests the negligence of food safety standards may result in increased microbial burden, which directly poses a threat to food safety and shelf life of food commodities.