Isolation of bacteria from milk based Indian sweets sold in and around Kolkata using MPN method

Abstract

Background: Milk based Indian sweets have a real cultural and culinary weight across much of the Indian subcontinent, yet their microbiological safety is still a worrying public health issue, especially in places where making, keeping, and delivery processes don’t follow consistent hygiene standards Objective: To check the microbiological quality of milk based Indian sweets that are commercially sold in and around Kolkata, India. This was done with the multiple tube test method Methods: We collected 80 samples of milk based Indian sweets from local vendors in and around Kolkata. After collection, microbiological testing was carried out using the multiple tube test in order to detect and, where possible, characterize bacterial contamination. The bacterial isolates that came up were then identified and their frequency was calculated as percentages out of the total number of samples examined. Results: From the 80 sweets analyzed, 64 samples (80%) were positive for bacterial contamination. In total, nine bacterial species were detected: Klebsiella aerogenes (28.75%), Enterobacter cloacae (15%), Escherichia coli (12.5%), Citrobacter koseri (8.75%), Klebsiella oxytoca (6.25%), Acinetobacter baumannii (2.5%), Citrobacter freundii (2.5%), Klebsiella pneumoniae (2.5%), and Aeromonas schubertii (1.25%). Overall, bacteria belonging to the Enterobacteriaceae family made up most of the isolates. Conclusion: Such a high presence of potentially pathogenic, or opportunistic bacteria in milk based Indian sweets creates serious concerns about food safety and consumer wellbeing in the Kolkata region. Also, the strong dominance of Enterobacteriaceae members suggests a notable risk of foodborne illness transmission.