The Gram-negative bacterium Klebsiella pneumoniae is a frequent pathogen causing outbreaks in neonatal intensive care units. Some Enterobacteriaceae can acquire the ability to sequester iron from infected tissue by secretion of iron-chelating compounds such as yersiniabactin. Here we describe an outbreak and clinical management of infections because of a highly virulent yersiniabactin-producing, nonmultiresistant K. pneumoniae strain in a neonatal intensive care unit. Outbreak investigation and effectiveness assessment of multidisciplinary infection control measurements to prevent patient-to-patient transmission of highly pathogenic K. pneumoniae were undertaken.
Outbreak cases were identified by isolation of K. pneumoniae from blood or stool of infants. Clinical data were abstracted from medical charts. K. pneumoniae isolates were genotyped using whole genome sequencing, and yersiniabactin production was evaluated by luciferase assay.
Fourteen cases were confirmed with 8 symptomatic and 6 colonized patients. Symptomatic patients were infants of extremely low gestational and chronologic age with fulminant clinical courses including necrotizing enterocolitis and sepsis. Whole genome sequencing for bacterial isolates confirmed the presence of an outbreak. All outbreak isolates produced yersiniabactin.
Yersiniabactin-producing K. pneumoniae can display a high pathogenicity in extremely premature infants with low chronologic age. This outbreak also underlines the considerable potential of today’s infection control systems for recognizing and controlling nosocomial infections in highly vulnerable populations.
From the *Department of Pediatrics and Adolescent Medicine, Division of Neonatology, Pediatric Intensive Care & Neuropediatrics, Medical University of Vienna
†Center for Anthropogenic Infections, Division for Public Health, Austrian Agency for Health and Food Safety
‡Department of Hospital Hygiene and Infection Control, Medical University of Vienna, Vienna, Austria
§Max von Pettenkofer-Institute, Ludwig Maximilian University (LMU), Munich, Germany.
Accepted for publication November 2, 2018.
Supported by a grant awarded under the “MedVetKlebs” Horizon 2020 Framework Programme H2020-SFS-2016–2017 (H2020-SFS-2017-1).
The authors have no potential conflict of interest to disclose.
Address for correspondence: Lukas Wisgrill, MD, Department of Pediatrics and Adolescent Medicine, Division of Neonatology, Pediatric Intensive Care & Neuropediatrics, Medical University of Vienna, Währinger Gürtel 18–20, 1090 Vienna, Austria. E-mail: email@example.com.