Transmission of Carbapenem-Resistant Klebsiella pneumoniae in US Hospitals.

BACKGROUND: Carbapenem-resistant Klebsiella pneumoniae (CRKp) is the most prevalent carbapenem-resistant Enterobacterales in the United States. We evaluated CRKp clustering in patients in US hospitals. METHODS: From April 2016 to August 2017, 350 patients with clonal group 258 CRKp were enrolled in the Consortium on Resistance Against Carbapenems in Klebsiella and other Enterobacteriaceae, a prospective, multicenter, cohort study. A maximum likelihood tree was constructed using RAxML. Static clusters shared ≤21 single-nucleotide polymorphisms (SNP) and a most recent common ancestor. Dynamic clusters incorporated SNP distance, culture timing, and rates of SNP accumulation and transmission using the R program TransCluster. RESULTS: Most patients were admitted from home (n = 150, 43%) or long-term care facilities (n = 115, 33%). Urine (n = 149, 43%) was the most common isolation site. Overall, 55 static and 47 dynamics clusters were identified involving 210 of 350 (60%) and 194 of 350 (55%) patients, respectively. Approximately half of static clusters were identical to dynamic clusters. Static clusters consisted of 33 (60%) intrasystem and 22 (40%) intersystem clusters. Dynamic clusters consisted of 32 (68%) intrasystem and 15 (32%) intersystem clusters and had fewer SNP differences than static clusters (8 vs 9; P = .045; 95% confidence interval [CI]: -4 to 0). Dynamic intersystem clusters contained more patients than dynamic intrasystem clusters (median [interquartile range], 4 [2, 7] vs 2 [2, 2]; P = .007; 95% CI: -3 to 0). CONCLUSIONS: Widespread intrasystem and intersystem transmission of CRKp was identified in hospitalized US patients. Use of different methods for assessing genetic similarity resulted in only minor differences in interpretation.

Bloodstream infections among intestinal and multivisceral transplant recipients.

OBJECTIVE: To examine the etiologies, risk factors, and microbiology of bloodstream infections (BSIs) among intestinal and multivisceral transplant recipients in the 2-year post-operative period. METHODS: A retrospective medical record review of adult intestinal or multivisceral transplant recipients between 2003 and 2015. Descriptive statistics were used to describe cohort data. Logistic regression was used to assess factors related to BSIs using a backward selection process. RESULTS: One-hundred and six intestinal or multivisceral transplants were performed in 103 individuals. Fifty-eight percent (n = 62) developed a BSI in the 2-year post-operative period with a median time to first BSI of 53 days (interquartile range [IQR] 15, 169). The majority of BSIs were catheter related 38% (n = 58) when the source was known. Common microbiological isolates included enterococcus 20% (n = 36/174), coagulase-negative staphylococcus 14% (n = 23), and 12% Klebsiella spp (n = 21). Forty-seven percent (n = 17) of the enterococci were resistant to vancomycin, and 14% (n = 10/70) of the gram negatives were extended spectrum beta-lactamase (ESBL) producers. In adjusted analyses, (OR: 0.200 95% CI: 0.2, 0.514, P = .009) men were less likely to have a BSI. Transplant recipient age, allograft type, comorbidities, rejection, and length of stay were not noted to be risk factors for development of BSIs in our cohort. Mortality at 2-years post-transplant was similar for those who did not develop a BSI and those that developed infection, P = .5028. CONCLUSIONS: BSIs are a common complication of intestinal transplantation, and central venous catheters were a common source. Interventions such as early catheter removal should be implemented to prevent infections in this population. Female sex association with BSI requires further investigation.