Outbreak of Yersiniabactin-producing Klebsiella pneumoniae in a Neonatal Intensive Care Unit

Abstract

Background: 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. Methods: 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. Results: 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. Conclusions: 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.

Characterization of antimicrobial-resistant Gram-negative bacteria that cause neonatal sepsis in seven low- and middle-income countries

“…BARNARDS isolates clustered with previously reported neonatal isolates, including ST45, ST48 and ST348 (refs. 15 , 22 , 23 ), but we also revealed distinct and new genetic lineages. The major AMR-related K. pneumoniae clades in Asia (ST11) and Europe (ST147 and ST307) 24 were also identified in this study.…”

“…K. pneumoniae is an important cause of neonatal sepsis in LMICs; however, there are few data analysing this species beyond antimicrobial susceptibility testing. Here, we have shown that K. pneumoniae was the most frequently identified GNB; therefore, the genomic diversity of this collection was scrutinized to contextualize these isolates, both within this study collection and within previously known collections 15 , 16 , 22 , 23 . K. pneumoniae ( n = 258) was found at all clinical sites (Figs.…”

“…b , Detailed core genome characterization of 309 K. pneumoniae isolates ( n = 258 BARNARDS). Yellow shading indicates isolates from other studies 15 , 22 causing neonatal sepsis. The outermost rings represent infant outcome (orange) and onset of sepsis (green), followed by the ST, where asterisks represent previously unknown STs.…”

“…Genomics analysis within both the global 15 , 16 , 22 (Fig. 5a ; see Supplementary Table 5 for literature search inclusion criteria) and neonatal sepsis context 23 (Fig.…”

First Report of Kosakonia radicincitans Bacteraemia from Europe (Austria) - Identification and Whole-Genome Sequencing of Strain DSM 107547

“…Such a finding simplifies the diagnosis of pathogenic bacteria significantly. The role of yersiniabactin (Ybt) in mediating the virulence of human pathogenic bacteria is unquestionable: (i) invasive enteric bacteria from the genera Yersinia, Escherichia, and Klebsiella secrete Ybt during human infection to combat host-mediated metal deficiencies 13 ; (ii) comparative genomics revealed that the list of horizontally transferred gene sets in Salmonella enterica is dominated by virulence factors and the yersiniabactin gene cluster 14 , suggesting an important role of this siderophore in human pathogenicity; and (iii) in addition to uropathogenic enterobacteria expressing Ybt 13 , it was shown very recently that all isolates of Klebsiella pneumoniae from infant blood or stool samples taken during outbreaks in neonatal intensive care units produced Ybt 15 .…”