Effects of streptomycin and kanamycin on the production of capsular polysaccharides in Escherichia coli B23 cells

Aminoglycosides are a class of antibiotics that inhibit protein synthesis in bacteria by binding to the 30S ribosomal subunit. However, it has been reported that certain aminoglycosides have secondary effects on the cell’s overall carbohydrate concentration. Previous studies have also reported an increase in capsule size. This study attempted to investigate the effects of kanamycin and streptomycin on carbohydrate production, particularly the sugars found in the capsular polysaccharides. Escherichia coli B23 was incubated in the presence of kanamycin and streptomycin. It was found that the concentration of glucuronic acid in the capsule increased in both the kanamycin and streptomycin treated cells, which correlated with the increase in the concentration of carbohydrate in the capsule and in the cell. However, a decrease in the amount of capsular 6-deoxyhexose was observed in streptomycin treated cells, correlating with a decrease in the overall concentration of 6-deoxyhexose. _______________________________________________________________