The prevalence of rectal carriage of Klebsiella pneumoniae amongst diabetic patients and their clinical relevance in Taiwan: A five-year prospective study

Background/purpose Pyogenic liver abscess (PLA) and bacteremia caused by Klebsiella pneumoniae is a common complication among patients with diabetes mellitus (DM). The aim of this study is to investigate the prevalence of rectal carriage and serotype distribution of K. pneumoniae amongst DM patients and their clinical relevance. Methods We prospectively collected rectal swabs for K. pneumoniae culture in asymptomatic DM patients from March 2008 to June 2009. Seven capsular serotypes that were commonly associated with PLA were determined by capsular polysaccharide synthesis (cps) genotyping. Microbiologically confirmed bacterial infections were evaluated 1 and 5 years after initial enrolment of the patients. Results A total of 100 male and 62 female patients (mean age, 56.6 years) were enrolled. Of these, 77 (47.5%) had rectal K. pneumoniae colonization. Colonizers were older than non-colonizers (p = 0.03). Sex, fasting blood glucose, and initial HbA1C were not statistically different (p = 0.26, 0.18, and 0.31, respectively). Among the 65 available isolates, 22 (33.8%) belonged to the seven main serotypes. During the 5-year's follow-up, 21 patients developed microbiologically documented bacterial infections but none of them developed PLA and bacteremia. Risk factors for bacterial infection within 5 years included initial glycosylated hemoglobin (HbA1C) > 10% or first-year average HbA1C > 10%. Conclusion Although nearly half of asymptomatic DM patients had rectal carriage of K. pneumoniae and one-third of them colonized by isolates belonging to the seven serotypes related to PLA, none of them subsequently developed PLA and colonized patients did not have higher risk of microbiologically confirmed bacterial infections.