Bacterial contaminants in carbonated soft drinks sold in Bangladesh markets

A total of 225 carbonated soft drink (CSD) samples from nine brands, from various locations in five metropolitan cities of Bangladesh were examined to determine their bacteriological quality. Most samples were not in compliance with microbiological standards set by organizations like the World Health Organization (WHO). Pseudomonas aeruginosa was the predominant species with an incidence of 95%. Streptococcus spp. and Bacillus stearothermophilus were the next most prevalent with numbers ranging from 6 to 122 and 9 to 105 cfu/100 ml, respectively. Fifty four percent of the samples yielded Salmonella spp. at numbers ranging from 2 to 90 cfu/100 ml. Total coliform (TC) and faecal coliform (FC) counts were found in 68–100% and 76–100% of samples of individual brands, at numbers ranging from 5 to 213 and 3 to 276 cfu/100 ml, respectively. According to WHO standards 60–88% of samples from six brands and 32% and 40% of samples from two other brands belonged to the intermediate risk group with FC counts of 100–1000 cfu/100 ml. Heterotrophic plate counts, however, were under the permissible limit in all 225 samples. These findings suggest that carbonated soft drinks commercially available in Bangladesh pose substantial risks to public health.