Intestinal mucositis, systemic inflammation and bloodstream infections following high-dose methotrexate treatment in childhood acute lymphoblastic leukaemia: Comparison between the NOPHO ALL 2008 protocol and the ALLTogether1 protocol.

Severe intestinal mucositis (IM) increases the risk of bloodstream infections (BSI) and inflammatory toxicity during acute lymphoblastic leukaemia (ALL) induction treatment. However, the implications of IM in subsequent ALL therapy phases after achieving remission remain unknown. This study investigated the relationship between IM (measured by plasma citrulline and the chemokine CCL20) and the development of BSI and systemic inflammation (reflected by C-reactive protein, CRP) in children with ALL during high-dose methotrexate (HDMTX) treatment, an important part of ALL consolidation therapy. The study compared patients treated according to the NOPHO ALL 2008 protocol (n = 52) and the ALLTogether1 protocol (n = 42), both with identical HDMTX procedures but different scheduling. One week post-HDMTX, citrulline dropped to median levels of 14.5 and 16.9 µM for patients treated according to the NOPHO ALL 2008 and ALLTogether1 protocols, respectively (p = 0.11). In a protocol and neutrophil count-adjusted analysis, hypocitrullinaemia (<10 µmol/L) was associated with increased odds of BSI within 3 weeks from HDMTX (OR = 26.2, p = 0.0074). Patients treated according to the NOPHO ALL 2008 protocol exhibited increased mucosal- and systemic inflammation post-HDMTX compared to patients treated according to ALLTogether1, with increased CCL20 (14.6 vs. 3.7 pg/mL, p < 0.0001) and CRP levels (10.0 vs. 1.0 mg/L, p < 0.0001). Both citrulline and CCL20 correlated with CRP for these patients (rs = -0.44, p = 0.0016 and rs = 0.35, p = 0.016, respectively). These results suggest that hypocitrullinaemia following HDMTX increases the risk of BSI, confirming previous observations from more intensive treatments. Moreover, these data indicate that the patients' vulnerability to mucositis and inflammatory toxicity after chemotherapy varies with treatment protocol.

Sampling for the diagnosis of orthopaedic surgical infections.

Orthopaedic surgical infections, in Denmark, are managed heterogeneously, both within the orthopaedic surgical and the clinical microbiological specialty. More uniform guidelines for sampling and clinical microbiological diagnostics for suspected orthopedic surgical infections would be appropriate. The purpose of this review is therefore to initiate a process aiming for consensus on sampling methods of tissue materials and fluids and clinical microbiological sample handling.

Association Between Vegetation Size and Outcome in the Partial Oral Antibiotic Endocarditis Treatment Trial.

Step-down oral antibiotic therapy is associated with a non-inferior long-term outcome compared with continued intravenous antibiotic therapy in the treatment of left-sided infective endocarditis. We aimed to analyze whether step-down oral therapy compared with continued intravenous antibiotic therapy is also associated with a non-inferior outcome in patients with large vegetations (vegetation length ≥ 10 mm) or among patients who underwent surgery before step-down oral therapy. We included patients without presence of aortic root abscess at diagnosis from the POET (Partial Oral Antibiotic Endocarditis Treatment) study. Multivariable Cox regression analyses were used to find associations between large vegetation, cardiac surgery, step-down oral therapy, and the primary end point (composite of all-cause mortality, unplanned cardiac surgery, embolic event, or relapse of positive blood cultures during follow-up). A total of 368 patients (age 68 ± 12, 77% men) were included. Patients with large vegetations (n = 124) were more likely to undergo surgery compared with patients with small vegetations (n = 244) (65% vs 20%, p <0.001). During a median 1,406 days of follow-up, 146 patients reached the primary end point. Large vegetations were not associated with the primary end point (hazard ratio 0.74, 95% confidence interval 0.47 to 1.18, p = 0.21). Step-down oral therapy was non-inferior to continued intravenous antibiotic in all subgroups when stratified by the presence of a large vegetation at baseline and early cardiac surgery. Step-down oral therapy is safe in the presence of a large vegetation at diagnosis and among patients who underwent early cardiac surgery.

The microenvironment in antibiotic susceptibility testing.

Antibiotic susceptibility testing (AST) by agar diffusion has been repeatedly standardized and, in most cases, gives results which predict clinical success when antibiotic treatment is based on such results. The formation of the inhibition zone is due to a transition from planktonic to biofilm mode of growth. The kinetics of the interaction of antibiotics with bacteria is similar during AST by agar diffusion and during administration of antibiotics to the patients. However, the Mueller-Hinton agar (MHA) recommended for AST agar diffusion test is fundamentally different from the composition of the interstitial fluid in the human body where the infections take place and human cells do not thrive in MH media. Use of RPMI 1640 medium designed for growth of eucaryotic cells for AST of Pseudomonas aeruginosa against azithromycin results in lower minimal inhibitory concentration, compared to results obtained by MHA. The reason is that the RPMI 1640 medium increases uptake and reduces efflux of azithromycin compared to MHA. During treatment of cystic fibrosis patients with azithromycin, mutational resistance occur which is not detected by AST with MHA. Whether this is the case with other antibiotics and bacteria is not known but it is of clinical importance to be studied.

Microbial Trends in Infection-related Readmissions Following Radical Cystectomy for Bladder Cancer.

OBJECTIVE: To report microbial pathogens detected at infection-related readmissions, including their susceptibility to antimicrobials. MATERIALS AND METHODS: A retrospective review of 785 patients who underwent radical cystectomy for bladder cancer at a tertiary center in Denmark between 2009 and 2019. All patients received prophylactic cefuroxime preoperatively and pivmecillinam at stent- or catheter removal. Data were collected through the national medical records and microbiology database. The primary outcome was readmission rate and pathogens detected at infection-related readmissions. Univariable and multivariable regression analyses were carried out to identify risk factors of readmission. RESULTS: Within 90days of surgery, 225 (29%) patients experienced at least one infection-related readmission. The most common pathogen identified was Enterococcus spp (24% of all positive samples). In blood cultures, the most dominant species were Escherichia coli (29%) and Staphylococcus spp (26%). Due to the heterogeneity in microbial species identified, more than one-third of the bacteria where mecillinam was tested showed resistance. Most isolates were susceptible to piperacillin+tazobactam. Orthotopic neobladder and continent cutaneous reservoir were associated with the highest risk of infection-related readmission compared to ileal conduit (odds ratios 2.78 [95%CI 1.66;4.65] and 3.08 [95%CI 1.58;5.98], respectively). Patients with diabetes had an increased risk of infection-related readmission compared to patients without diabetes (odds ratio 1.67 [95%CI 1.02;2.73]). CONCLUSION: Nearly one-third of all patients experienced at least one postoperative infection-related readmission with a wide range of microbial etiologies. Generalizability of our results is uncertain, but the data can be used to plan interventional trials of antibiotic prophylaxis.

Markers of intestinal mucositis to predict blood stream infections at the onset of fever during treatment for childhood acute leukemia.

Despite chemotherapy-induced intestinal mucositis being a main risk factor for blood stream infections (BSIs), no studies have investigated mucositis severity to predict BSI at fever onset during acute leukemia treatment. This study prospectively evaluated intestinal mucositis severity in 85 children with acute leukemia, representing 242 febrile episodes (122 with concurrent neutropenia) by measuring plasma levels of citrulline (reflecting enterocyte loss), regenerating islet-derived-protein 3α (REG3α, an intestinal antimicrobial peptide) and CCL20 (a mucosal immune regulatory chemokine) along with the general neutrophil chemo-attractants CXCL1 and CXCL8 at fever onset. BSI was documented in 14% of all febrile episodes and in 20% of the neutropenic febrile episodes. In age-, sex-, diagnosis- and neutrophil count-adjusted analyses, decreasing citrulline levels and increasing REG3α and CCL20 levels were independently associated with increased odds of BSI (OR = 1.6, 1.5 and 1.7 per halving/doubling, all p < 0.05). Additionally, higher CXCL1 and CXCL8 levels increased the odds of BSI (OR = 1.8 and 1.7 per doubling, all p < 0.0001). All three chemokines showed improved diagnostic accuracy compared to C-reactive protein and procalcitonin. These findings underline the importance of disrupted intestinal integrity as a main risk factor for BSI and suggest that objective markers for monitoring mucositis severity may help predicting BSI at fever onset.

Clinical implementation of partial oral treatment in infective endocarditis: the Danish POETry study.

BACKGROUND AND AIMS: In the Partial Oral Treatment of Endocarditis (POET) trial, stabilized patients with left-sided infective endocarditis (IE) were randomized to oral step-down antibiotic therapy (PO) or conventional continued intravenous antibiotic treatment (IV), showing non-inferiority after 6 months. In this study, the first guideline-driven clinical implementation of the oral step-down POET regimen was examined. METHODS: Patients with IE, caused by Staphylococcus aureus, Enterococcus faecalis, Streptococcus spp. or coagulase-negative staphylococci diagnosed between May 2019 and December 2020 were possible candidates for initiation of oral step-down antibiotic therapy, at the discretion of the treating physician. The composite primary outcome in patients finalizing antibiotic treatment consisted of embolic events, unplanned cardiac surgery, relapse of bacteraemia and all-cause mortality within 6 months. RESULTS: A total of 562 patients [median age 74 years (IQR, interquartile range, 65-80), 70% males] with IE were possible candidates; PO was given to 240 (43%) patients and IV to 322 (57%) patients. More patients in the IV group had IE caused by S. aureus, or had an intra-cardiac abscess, or a pacemaker and more were surgically treated. The primary outcome occurred in 30 (13%) patients in the PO group and in 59 (18%) patients in the IV group (P = .051); in the PO group, 20 (8%) patients died vs. 46 (14%) patients in the IV group (P = .024). PO-treated patients had a shorter median length of stay [PO 24 days (IQR 17-36) vs. IV 43 days (IQR 32-51), P < .001]. CONCLUSIONS: After clinical implementation of the POET regimen almost half of the possible candidates with IE received oral step-down antibiotic therapy. Patients in the IV group had more serious risk factors for negative outcomes. At 6-month follow-up, there was a numerically but not statistically significant difference towards a lower incidence of the primary outcome, a lower incidence of all-cause mortality and a reduced length of stay in the PO group. Due to the observational design of the study, the lower mortality may to some extent reflect selection bias and unmeasured confounding. Clinical implementation of PO regimens seemed feasible and safe.

Gastrointestinal barrier integrity and mucosal inflammation as risk factors of blood stream infections in children treated for acute lymphoblastic leukaemia.

Chemotherapy-induced mucositis increases the risk of blood stream infections (BSI) due to translocation of bacteria across the intestinal epithelium. Our study investigated if quantitative measures of intestinal mucositis severity, including plasma citrulline (a marker of functional enterocytes) and CCL20 (an intestinal immune homeostatic chemokine), could identify patients at risk of BSI. A total of 106 children with ALL undergoing induction treatment (NOPHO ALL 2008) were included and information regarding BSI episodes was collected from the patients' medical records. Twenty-seven patients (25%) developed BSI during induction. Patients with BSI had a larger decrease in citrulline after chemotherapy than patients without BSI, and nearly all BSI episodes (25/27) occurred in the group of patients exhibiting a drop in citrulline (OR = 6.4 [95% CI: 1.4-29.3], P = .008). Patients who developed BSI had higher plasma CCL20 levels on days 8, 15 and 22 than patients without BSI (all P < .05), and elevated CCL20 levels on day 8 increased the risk of subsequent BSI (OR = 1.57 [1.11-2.22] per doubling of CCL20 level, P = .01) in a multivariable logistic regression analysis. These findings suggest that children with ALL who develop BSI during chemotherapy are characterised by more severe intestinal mucositis, as measured by plasma citrulline and CCL20. These markers may be useful in early risk stratification to guide treatment decisions.

Markers of neutrophil chemotaxis for identification of blood stream infections in children with acute lymphoblastic leukemia undergoing induction treatment.

BACKGROUND: Although neutropenic fever is frequently observed during chemotherapy, only a minor proportion is caused by blood stream infections (BSI). This study investigated measurements of neutrophil chemotaxis as risk markers for BSI in children with acute lymphoblastic leukemia (ALL). METHODS: The chemokines CXCL1 and CXCL8 were measured weekly in 106 children with ALL during induction treatment. Information regarding BSI episodes was collected from the patients' medical records. RESULTS: During induction treatment, 102 (96%) patients developed profound neutropenia and 27 (25%) were diagnosed with BSI, debuting on median day 12 (range: 4-29). Patients developing BSI had increased levels of CXCL1 on days 8 and 15 as well as increased CXCL8 on days 8, 15, 22, and 29 compared to patients without BSI (all p < 0.05). Patients with BSI < day 12 exhibited increased CXCL1 and CXCL8 levels as early as day 8 (81 vs. 4 pg/mL, p = 0.031 and 35 vs. 10 pg/mL, p < 0.0001, respectively), while CXCL1 and CXCL8 were increased on day 15 (215 vs. 57 pg/mL, p = 0.022 and 68 vs. 17 pg/mL, p = 0.0002) and after (all p < 0.01) in patients with BSI ≥ day 12. CONCLUSION: The markers of neutrophil chemotaxis, CXCL1, and CXCL8 may help to identify patients at increased risk of BSI during chemotherapy-induced neutropenia.

Chicken IgY reduces the risk of Pseudomonas aeruginosa urinary tract infections in a murine model.

Introduction: Urinary tract infections (UTIs) with Pseudomonas aeruginosa are a severe problem in disposed patients in modern healthcare. Pseudomonas aeruginosa establishes recalcitrant biofilm infections and can develop antibiotic resistance. Gargling with avian egg yolk anti-Pseudomonas antibodies (IgY) has shown clinical effect in preventing onset of chronic P. aeruginosa lung infections in patients with cystic fibrosis (CF). Therefore, we speculated whether passive intravesically administered IgY immunotherapy could be a novel strategy against P. aeruginosa UTIs. Aim: To evaluate if prophylactic repurposing of anti-Pseudomonas IgY can prevent UTIs with P. aeruginosa in a UTI mouse model. Materials and methods: In vitro, P. aeruginosa (PAO1 and PAO3) was mixed with increasing concentrations of specific anti-Pseudomonas IgY (sIgY) or non-specific control IgY (cIgY) and/or freshly isolated human neutrophils. Bacterial growth was evaluated by the optical density at 600 nm. In vivo, via a temporary transurethral catheter, 10-week-old female Balb/c mice were intravesically infected with 50 ml of a bacterial suspension and sIgY, cIgY, or isotonic NaCl. IgY and NaCl were either co-instilled with the bacteria, or instilled prophylactically, 30 min prior to infection. The animals were euthanized 20 h after infection. Vesical bacteriology was quantified, and cytokine expression in the bladder homogenate was measured by multiplex cytokine assay. Results: In vitro, sIgY concentrations above 2.5% reduced bacterial growth in a dose-dependent manner. In vivo, a UTI lasting for minimum 7 days was established by installing 5 × 106 colony-forming units (CFU) of P. aeruginosa PAO1. sIgY reduced vesical bacterial load if co-installed with P. aeruginosa PAO1. Prophylactic sIgY and cIgY reduced bacterial load when compared to isotonic NaCl. CXCL2 and G-CSF were both increased in infected bladders compared to non-infected controls which had non-detectable levels. Co-installation of sIgY and bacteria nearly completely inhibited the inflammatory response. However, the cytokine levels in the bladder did not change after prophylactic administration of sIgY or cIgY. Conclusion: Prophylactic sIgY significantly reduces the amount of bacteria in the bladder in a mouse model of P. aeruginosa cystitis and may serve as a novel non-antibiotic strategy in preventing P. aeruginosa UTIs.