Risk of death in Klebsiella pneumoniae bloodstream infections is associated with specific phylogenetic lineages.

BACKGROUND: Klebsiella pneumoniae species complex (KpSC) bloodstream infections (BSIs) are associated with considerable morbidity and mortality, particularly in elderly and multimorbid patients. Multidrug-resistant (MDR) strains have been associated with poorer outcome. However, the clinical impact of KpSC phylogenetic lineages on BSI outcome is unclear. METHODS: In an 18-month nationwide Norwegian prospective study of KpSC BSI episodes in adults, we used whole-genome sequencing to describe the molecular epidemiology of KpSC, and multivariable Cox regression analysis including clinical data to determine adjusted hazard ratios (aHR) for death associated with specific genomic lineages. FINDINGS: We included 1078 BSI episodes and 1082 bacterial isolates from 1055 patients. The overall 30-day case-fatality rate (CFR) was 12.5%. Median patient age was 73.4, 61.7% of patients were male. Median Charlson comorbidity score was 3. Klebsiella pneumoniae sensu stricto (Kp) (79.3%, n = 858/1082) and K. variicola (15.7%, n = 170/1082) were the dominating phylogroups. Global MDR-associated Kp clonal groups (CGs) were prevalent (25.0%, n = 270/1082) but 78.9% (n = 213/270) were not MDR, and 53.7% (n = 145/270) were community acquired. The major findings were increased risk for death within 30 days in monomicrobial BSIs caused by K. variicola (CFR 16.9%, n = 21; aHR 1.86, CI 1.10-3.17, p = 0.02), and global MDR-associated Kp CGs (CFR 17.0%, n = 36; aHR 1.52, CI 0.98-2.38, p = 0.06) compared to Kp CGs not associated with MDR (CFR 10.1%, n = 46). CONCLUSION: Bacterial traits, beyond antimicrobial resistance, have a major impact on the clinical outcome of KpSC BSIs. The global spread of MDR-associated Kp CGs is driven by other mechanisms than antibiotic selection alone. Further insights into virulence determinants, and their association with phylogenetic lineages are needed to better understand the epidemiology of KpSC infection and clinical outcome.

Donor-derived strongyloidiasis after organ transplantation in Norway.

Strongyloides stercoralis is an intestinal helminth which in humans can cause asymptomatic chronic infection maintained for decades through its auto-infective cycle. During solid organ transplantation, recipients may unintentionally receive an organ infected with strongyloides. This is a very rare complication but may have deadly outcome if not detected. We hereby report two transplant recipients whom developed Strongyloides hyperinfection syndrome after organ transplantation from the same deceased donor. Recipient 1 was kidney transplanted and presented at day 65 post engraftment with diarrhea and subsequent septicemia and gastric retention. Larvae were detected in gastric aspirate. Recipient 2 was simultaneously kidney and pancreas transplanted and presented at day 90 post engraftment also with gastric retention and septicemia. Larvae were demonstrated on duodenal biopsy and stool sample. The clinical course was complicated with severe duodenal bleedings, gastric retention, meningitis, and prolonged hospitalization. Retrospective testing of pre-transplant donor serum was positive for Strongyloides stercoralis antibodies. As a result of disease severity and gastric retention albenazole was administered via a jejunal tube and ivermectin subcutaneously in both recipients. S stercoralis was successfully eradicated and the transplants ended up with unaffected graft function. Following these two cases, we started systematic screening of all deceased donors for serum Strongyloides IgG in October 2016. After having screened 150 utilized donors one tested positive for Strongyloides, which initiated prophylactic ivermectin treatment to organ recipients. No symptoms or disease developed. Our center will continue to screen all donors as prophylactic treatment may avert this potentially lethal complication in cases of donor-derived Strongyloides infection.