Microbial contamination of ice used in street beverages in Dhaka

Abstract

Street-vended beverages are widely consumed in Dhaka, especially during hot and humid weather. While previous studies have focused on microbial contamination in juices, limited attention has been given to the ice used during preparation despite its potential to transmit enteric pathogens when handled or produced under poor sanitary conditions. This study aimed to investigate microbial contamination in both ice and juice samples from two busy areas of Dhaka Merul Badda and Gulshan-1 and to evaluate associated public health risks. A total of 18 samples of juice and ice (from orange and watermelon juices) were collected. Microbiological analysis included serial dilutions, culture on selective media (MacConkey and KPC agar), Gram staining, polymerase chain reaction (PCR), and antimicrobial susceptibility testing (AST). Out of 18 samples, 6 (33.3%) tested positive for bacterial contamination. Among these, 4 samples (22.2%) were positive for Escherichia coli, all from watermelon juice and related ice in Gulshan-1. Two samples (11.1%) were positive for Klebsiella pneumoniae, one from orange juice ice in Merul Badda and another from watermelon juice ice in Gulshan-1. The highest bacterial loads were observed in Gulshan-1, with E. coli reaching 6.8 × 10⁴ CFU/mL in juice and 8.2 × 10⁴ CFU/mL in ice. PCR was conducted to amplify the DNA of the isolated bacteria, and gel electrophoresis revealed distinct bands—at 585 bp for E. coli and 130 bp for K. pneumoniae—supporting their identification. The study aims at examining the Antibiotic Resistance Profile of Escherichia coli (n=4) and Klebsiella pneumoniae (n= 2) battery isolated through Antimicrobial Susceptibility Testing (AST) in samples under clinical investigation. The findings showed that there was a huge rate of multidrug resistance and that the two species are 100% resistant to most of the antibiotics that were used in the test. The E. coli exhibited partial resistance towards ciprofloxacin (25%) and nitrofurantoin (50%) and the K. pneumoniae displayed resistance of 50% to nitrofurantoin only. These results indicate the increasing problem of the antimicrobial resistance and the serious necessity of effective antibiotic stewardship, constant surveillance, and elaboration of alternative treatment regimens to address resistant bacterial infections.