Clinical characteristics, antimicrobial resistance and capsular types of community-acquired, healthcare-associated, and nosocomial Klebsiella pneumoniae bacteremia

BACKGROUND: Klebsiella pneumoniae bacteremia is a major cause of morbidity and mortality worldwide. We aimed to compare the clinical characteristics, distribution of capsular types, and antimicrobial resistance of K. pneumoniae bacteremia among community-acquired (CA), healthcare-associated (HCA), and nosocomial infections. METHODS: This retrospective study of patients with K. pneumoniae bacteremia was conducted at Taipei Veterans General Hospital from January to December 2015. Clinical characteristics of K. pneumoniae bacteremia were collected. The K. pneumoniae isolates were subjected to antimicrobial susceptibility testing and capsular genotyping. RESULTS: In total, 337 patients with K. pneumoniae bacteremia were identified: 70 (20.8%), 102 (30.3%), and 165 (48.9%) presented with CA, HCA, and nosocomial infection, respectively. The 28-day mortality of HCA bacteremia was lower than that of nosocomial bacteremia (17.6% versus 30.9%, p = 0.016); however, that of the HCA and CA bacteremia was similar (17.6% versus 14.3%, p = 0.557). CA isolates had the highest prevalence of virulent capsular types (51.4%), followed by HCA (36.3%) and nosocomial isolates (19.4%). The proportion of multidrug-resistant (MDR) isolates was highest in nosocomial infections (41.8%), followed by HCA (23.5%) and CA infections (5.7%). CONCLUSION: CA, HCA and nosocomial K. pneumoniae are distinct entities, as evidenced by the differences in clinical characteristics, antimicrobial resistance, and capsular types found in this study.