824. Clinical and microbiological characteristics of primary bacteremia caused by Klebsiella pneumoniae: a post-hoc analysis of prospective nationwide surveillance
Session: Poster Abstract Session: Bacteremia and Endocarditis
Friday, October 9, 2015
Room: Poster Hall
Background: Various clinical syndromes caused by K. pneumoniae (KPN) have been well studied. But the source of infection is often unknown, and previous studies on the primary bacteremia caused by KPN (KPN-PB) have been scarce. The aim of this study is to elucidate the risk factors for KPN-PB and to examine the microbiologic characteristics and clinical outcomes of KPN-PB.

Methods: This study is a post-hoc analysis of prospective nationwide surveillance of bloodstream infections. Microbiological data of all blood culture isolates were collected from 13 institutions in Korea from June to September 2011. Retrospective review of medical records was conducted for bloodstream infections by KPN. Isolates of KPN were collected for serotyping, multilocus sequence typing (MLST), and PCR for rmpA and aerobactin.

Results: Total of 224 cases of KPN bacteremia was identified. Source of infection could not be identified in sixty-two (27.7%) cases, thus classified to KPN-PB and the remaining to non-PB group. Solid tumor, hematologic disease, absence of renal disease, and not receiving invasive procedure within previous 72 h were independently associated with KPN-PB in multivariate analysis. Resistance rates to 3rd generation cephalosporins or to fluoroquinolones were not significantly different between the two groups. Serotype K1 and aerobactin gene were found less commonly in KPN-PB (9.1% vs. 22.9% and 38.6% vs. 57.1%, respectively). K1/2 serotype and presence of virulence genes were more common in community-associated infections. MLST for 28 K1 isolates revealed the predominance of ST 23. Overall 30-day mortality rate was 23.1%. Multivariate logistic regression analysis identified septic shock as initial presentation and higher PITT score as risk factors for 30-day mortality. Primary bacteremia was not found to be associated with clinical outcome in both univariate and multivariate analysis.

Conclusion: Malignancy, absence of renal disease, and no history of recent invasive procedure were independently associated with KPN-PB. Severe initial presentation was risk factors for mortality, and the clinical outcome of KPN-PB did not differ from that of non-KPN-PB.

Kyungmin Huh, MD1,2, Kyong Ran Peck, MD2, Jinyang Baek, MSc3, Cheol-in Kang, MD2, Doo Ryeon Chung, MD, PhD2, Nam Yong Lee, MD, PhD4, Jae-Hoon Song, MD PhD2 and Korean Network for Study on Infectious Diseases, (1)Division of Infectious Diseases, Armed Forces Capital Hospital, Sungnam, South Korea, (2)Division of Infectious Diseases, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea, (3)Asian Pacific Foundation for Infectious Diseases, Seoul, South Korea, (4)Department of Laboratory Medicine and Genetics, Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, South Korea

Disclosures:

K. Huh, None

K. R. Peck, None

J. Baek, None

C. I. Kang, None

D. R. Chung, None

N. Y. Lee, None

J. H. Song, None

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