Co-outbreak of ST37 and a novel ST3006 Klebsiella pneumoniae from multi-site infection in a neonatal intensive care unit: a retrospective study

Abstract

21 sequencing; Neonatal intensive care unit 22 23 2 Summary 24 Background: The spread of carbapenem resistance among Klebsiella pneumoniae (K. 25 pneumoniae) is a major public health problem, particularly in neonatal intensive care 26 units (NICUs).27Aim: To describe the nosocomial co-outbreak of ST37 and a new sequence type 28 ST3006 K. pneumoniae, causing catheter-related bloodstream infections in NICU. 29Methods: Fifteen strains of K. pneumoniae were isolated from seven neonates during 30 June 3-28, 2013, in a tertiary hospital neonatal intensive care unit in Fujian, China. 31Antimicrobial susceptibility was determined by the Vitek 2 system and micro-broth 32 dilution method. Multi-locus sequence typing (MLST) and pulsed-field gel 33 electrophoresis (PFGE) were used to analyse the genetic relatedness of isolates. 34Genome sequencing and gene function analyses were performed for investigating 35 pathogenicity and drug resistance and screening genomic islands. 36Findings: Two K. pneumoniae clones were identified from seven neonates with 37 multi-site infection, one ST37 strain and one new sequence type ST3006. 38Antimicrobial susceptibility testing revealed that the ST37 strain exhibited multi-drug 39 resistance and carbapenem resistance. The ST3006 strain was only resistant to 40 ampicillin-sulbactam, cefazolin, ceftriaxone. MLST and PFGE showed that 15 strains 41 were divided into three groups, with a high level of homology. Gene sequencing and 42 analysis indicated that KPN1343 harboured 12 resistance genes, 15 genomic islands 43 and 205 reduced virulence genes. KPN1344 harboured four resistance genes, 19 44 genomic islands and 209 reduced virulence genes. 45 Conclusion: Co-outbreak of K. pneumoniae involved two clones, ST36 and ST3006, 46 causing multi-site infection. Genome sequencing and analysis is an effective method 47 for studying bacterial resistance genes and their functions.48 49 50 Introduction 51 Klebsiella pneumonia, particularly multidrug resistant K. pneumoniae, is a 52 common and important pathogen in hospitals, posing a serious and urgent threat to 53 public health (1, 2). Neonates in the neonatal intensive care units often have 54 underlying conditions, such as prematurity, or the presence of indwelling catheters, a 55 history of antibiotic treatment and parenteral nutrition, which are risk factors for 56 infection (3). In addition, relaxed vigilance by doctors and nurses regarding 57 nosocomial infection promotes nosocomial infection outbreaks, with considerable 58 impact on neonatal treatment and prognosis, prolonged hospital stays, increased 59 hospital costs and mortality. 60 Nosocomial outbreaks in the neonatal intensive care unit are frequently reported 61(4-7); however, it is rare to isolate the same clonal pathogen from different sites in the 62 same patient. This study identified 15 K. pneumoniae strains isolated from sputum 63 specimens, blood specimens and umbilical vein catheter tips in seven neonates that 64 belonged to the two cloned strains ST37 and ST3006, which produced carb...

Prevalence and risk factors for antimicrobial resistance among newborns with gram-negative sepsis

“…The clustered occurrence of some Klebsiella pneumoniae ( Kp ) strains suggests possible outbreaks and may provide clues about infection sources in this study. Strains ST35 and ST37, which were responsible for more than half of all GNB sepsis in this study, have been associated with MDR and reported to be sources of outbreaks within NICU settings outside sSA [ 59 – 61 ]. Both ST35 and ST37 have also been detected in the feces of healthy adults and animals in the community [ 62 ].…”