Impact of glycemic control on capsular polysaccharide biosynthesis and opsonophagocytosis of Klebsiella pneumoniae: Implications for invasive syndrome in patients with diabetes mellitus

ABSTRACTKlebsiella pneumoniae (KP), with production of abundant capsular polysaccharide (CPS), is capable of causing invasive syndrome. Environmental glucose stimuli may increase CPS biosynthesis. We aimed to investigate the relationship between glycemic control and KP-mediated invasive syndrome in diabetic patients and the effect of glucose on CPS biosynthesis. Diabetic patients with community-acquired KP bacteremia were included to study the risk factors of invasive syndrome. KP-M1, a serotype-K1 KP clinical isolate, was used to examine the CPS biosynthesis and cps gene expression, and the effect of exogenous glucose on bacterial phagocytosis and killing. We found that invasive syndrome was significantly more common in diabetic patients who were infected with strains expressing the K1 serotype (adjusted odds ratio [AOR], 8.32; 95% confidence interval [CI], 1.56−44.24; p=0.01), and had poor glycemic control (HbA1c ≥9%; AOR, 5.66; 95% CI, 2.01−15.92; p<0.01). Pre-incubation of KP-M1 in media containing di...