title: Increase in Antibiotic-Resistant Gram-Negative Bacterial Infections in Febrile Neutropenic Children.
abstract: BACKGROUND
  The incidence of bacteremia caused by Gram-negative bacteria has increased recently in febrile neutropenic patients with the increase of antibiotic-resistant Gram-negative bacterial infections. This study aimed to identify the distribution of causative bacteria and the proportion of antibiotic-resistant bacteria in bacteremia diagnosed in febrile neutropenic children.
  
  
  METHODS
  The medical records of febrile neutropenic children diagnosed with bacteremia between 2010 and 2014 were retrospectively reviewed. The causative bacteria and proportion of antibiotic-resistant bacteria were investigated and compared yearly during the study period. The clinical impact of antibiotic-resistant bacterial infections was also determined.
  
  
  RESULTS
  A total of 336 bacteremia episodes were identified. During the entire study period, 181 (53.9%) and 155 (46.1%) episodes were caused by Gram-negative and Gram-positive bacteria, respectively. Viridans streptococci (25.9%), Klebsiella spp. (16.7%), and Escherichia coli (16.4%) were the most frequent causative bacteria. The overall distribution of causative bacteria was not significantly different annually. Antibiotic-resistant bacteria were identified in 85 (25.3%) episodes, and the proportion of antibiotic-resistant bacteria was not significantly different annually. Extended-spectrum β-lactamase-producing E. coli and Klebsiella spp. were most common among antibiotic-resistant Gram-negative bacteria, and they accounted for 30.6% (n = 34) of the identified E. coli and K. pneumoniae. Methicillin-resistant coagulase-negative staphylococci were most common among antibiotic-resistant Gram-positive bacteria, and it accounted for 88.5% (n = 23) of the identified coagulase-negative staphylococci. Antibiotic-resistant bacterial infections, especially antibiotic-resistant Gram-negative bacterial infections, caused significantly higher mortality due to bacteremia compared with non-antibiotic-resistant bacterial infections (P < 0.001).
  
  
  CONCLUSIONS
  Recently, Gram-negative bacteria caused more bacteremia cases than Gram-positive bacteria in febrile neutropenic children, and antibiotic-resistant Gram-negative bacterial infections increased. Antibiotic-resistant bacterial infections caused poorer prognosis compared with non-antibiotic-resistant bacterial infections, and therefore, continuous surveillance for changing epidemiology of antibiotic-resistant bacterial infections and their clinical impact is necessary.
authors.affiliation: Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Joon Hee
authors.identifier: http://orcid.org/0000-0001-9530-2105
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Seul Ki
authors.identifier: http://orcid.org/0000-0002-9281-0320
authors.initials: SK
authors.lastname: Kim
authors.affiliation: Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Korea.|The Catholic Blood and Marrow Transplantation Center, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Seong Koo
authors.identifier: http://orcid.org/0000-0002-1860-3067
authors.initials: SK
authors.lastname: Kim
authors.affiliation: Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Korea.|The Vaccine Bio Research Institute, College of Medicine, The Catholic University of Korea, Seoul, Korea. beomsid@catholic.ac.kr.
authors.forename: Seung Beom
authors.identifier: http://orcid.org/0000-0002-1299-2137
authors.initials: SB
authors.lastname: Han
authors.affiliation: Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Korea.|The Catholic Blood and Marrow Transplantation Center, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Jae Wook
authors.identifier: http://orcid.org/0000-0002-0735-0287
authors.initials: JW
authors.lastname: Lee
authors.affiliation: The Catholic Blood and Marrow Transplantation Center, College of Medicine, The Catholic University of Korea, Seoul, Korea.|The Vaccine Bio Research Institute, College of Medicine, The Catholic University of Korea, Seoul, Korea.|Division of Infectious Diseases, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Dong Gun
authors.identifier: http://orcid.org/0000-0003-4655-0641
authors.initials: DG
authors.lastname: Lee
authors.affiliation: Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Korea.|The Catholic Blood and Marrow Transplantation Center, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Nack Gyun
authors.identifier: http://orcid.org/0000-0003-4855-390X
authors.initials: NG
authors.lastname: Chung
authors.affiliation: Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Korea.|The Catholic Blood and Marrow Transplantation Center, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Bin
authors.identifier: http://orcid.org/0000-0001-6675-695X
authors.initials: B
authors.lastname: Cho
authors.affiliation: Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Korea.|The Vaccine Bio Research Institute, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Dae Chul
authors.identifier: http://orcid.org/0000-0003-0934-817X
authors.initials: DC
authors.lastname: Jeong
authors.affiliation: Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Korea.|The Vaccine Bio Research Institute, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Jin Han
authors.identifier: http://orcid.org/0000-0003-1610-6742
authors.initials: JH
authors.lastname: Kang
authors.affiliation: Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Korea.|The Catholic Blood and Marrow Transplantation Center, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Hack Ki
authors.identifier: http://orcid.org/0000-0001-7298-4596
authors.initials: HK
authors.lastname: Kim
keywords: Antibiotic resistance; Bacteremia; Child; Fever; Neutropenia