Impact of fluoroquinolone administration and gut mucosal colonization on the risk of pre-engraftment bloodstream infections after allogeneic hematopoietic cell transplantation

Fluoroquinolones (FQ) has been used after allogeneic hematopoietic stem cell transplantation (allo-HCT) for decades. This study on 284 allo-HCT recipients aimed to analyze the impact of FQ on pre-engraftment BSI. A total of 154 patients were colonized with resistant gram-negative bacteria, and 130 patients were not. Colonized patients did not receive FQ (n = 147) except 7 who received FQ as sequential therapy; 98 non-colonized patients received FQ, whereas 32 did not. Gram-negative (p < 0.0001), and ESBL-E BSI (p < 0.0001) were higher in colonized patients receiving FQ. No difference was found in gram-positive BSI (p = 0.452). In multivariate analysis colonized patients with (p < 0.0001) or without FQ (p = 0.007), omission of FQ in non-colonized patients (p = 0.038), and active disease (p = 0.042) were associated with gram-negative BSI, whereas mismatched unrelated donor transplantations - with gram-positive BSI (p = 0.009). Colonized patients with FQ have a higher risk of gram-negative BSI. In non-colonized patients, FQ prophylaxis is effective approach significantly reducing gram-negative BSI risk.

The Use and Effectiveness of Ceftazidime-Avibactam in Real-World Clinical Practice: EZTEAM Study

INTRODUCTION

Ceftazidime-avibactam has proven activity against multidrug-resistant (MDR) bacteria in clinical trials and real-world studies. This study was conducted to describe the patterns of use of ceftazidime-avibactam (including indications and associated antibiotics), and the effectiveness and safety of ceftazidime-avibactam in real-world clinical practice.

METHODS

This non-interventional medical chart review study was conducted in 11 countries across the European and Latin American (LATAM) regions. Consecutive patients treated in clinical practice with at least one dose of ceftazidime-avibactam for an approved indication per country label since 01 January 2018 (or launch date in the country if posterior) were enrolled. Effectiveness analyses were conducted in patients treated with ceftazidime-avibactam for at least 72 h.

RESULTS

Of the 569 eligible patients enrolled, 516 (90.7%) were treated for at least 72 h (354 patients from Europe and 162 patients from LATAM); 390 patients (75.7%) had switched from another antibiotic line for Gram-negative coverage. Infection sources were intra-abdominal, urinary, respiratory, bloodstream infections, and other infections (approximately 20% each). K. pneumoniae was the most common microorganism identified in the latest microbiological evaluation before starting ceftazidime-avibactam (59.3%). Two-thirds of microorganisms tested for susceptibility were MDR, of which 89.3% were carbapenem-resistant. The common MDR mechanisms for K. pneumoniae were carbapenemase (33.9%), oxacillinase 48 (25.2%), extended-spectrum beta-lactamase (21.5%), or metallo-beta-lactamase (14.2%) production. Without prior patient exposure, 17 isolates (mostly K. pneumoniae) were resistant to ceftazidime-avibactam. Treatment success was achieved in 77.3% of patients overall (88.3% among patients with urinary infection), regardless of first or second treatment line. In-hospital mortality rate was 23.1%. Adverse events were reported for six of the 569 patients enrolled.

CONCLUSION

This study provides important real-world evidence on treatment patterns, effectiveness, and safety of ceftazidime-avibactam in clinical practice through its recruitment in the European and LATAM regions. Ceftazidime-avibactam is one of the antibiotics to consider for treatment of MDR bacteria.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT03923426.

Recurrent bloodstream infections after allogeneic hematopoietic cell transplantation

BACKGROUND

Although colonization is an established risk factor for bloodstream infection (BSI) due to identical strain, prior infection with resistant bacteria should also be considered during the management of febrile neutropenia. This study aimed to analyze the rate and etiology of recurrent BSI in allogeneic hematopoietic cell transplant (allo-HCT) recipients to determine its potential impact on decision-making.

MATERIALS AND METHODS

The retrospective study included 284 allo-HCT recipients. Recurrent BSI was defined as a new BSI episode occurring in a period of more than 72 hours after antibiotic withdrawal.

RESULTS

Overall, 104 patients (36.6%) developed at least one BSI, and 23 of them (22.1%) experienced recurrent BSI episodes (n = 30). Median time to recurrent BSI was 41 days (range 5-526 days). Recurrent BSI was associated with second allo-HCT (p < 0.0001), primary (p = 0.021), and secondary graft failure (p = 0.024). Carbapenem-resistant gram-negative bacteria were more common during recurrent BSI episodes (23.7% vs. 6.0%; p = 0.003). In only 17.5% patients experiencing recurrent BSI episode and in only 3.9% of patients with at least one BSI episode phenotypically identical recurring pathogen was isolated.

CONCLUSIONS

In view of low rate of recurrent BSI due to identical pathogen, empirical antimicrobial therapy should not be based on data on previous BSI episodes.

Post-engraftment Bloodstream Infections After Allogeneic Hematopoietic Cell Transplantation: Risk Factors and Association with Mortality

BACKGROUND

Bloodstream infections (BSIs) are major cause of morbidity and mortality after allogeneic hematopoietic cell transplantation (allo-HCT). This study aimed to analyze the incidence, etiology, risk factors and outcomes of post-engraftment BSI in allo-HCT recipients.

MATERIALS AND METHODS

The retrospective study included 261 patients with documented engraftment after first allo-HCT performed from January 2018 till September 2021.

RESULTS

Of 261 patients 29 (11.1%) developed at least one post-engraftment BSIs episode with a median time to post-engraftment BSI of 49 days (range, 1 - 158 days from the engraftment). A total of 45 pathogens were isolated from blood - 64.4% (n = 29) were represented by Gram-negative bacteria, and 35.6% (n = 16) - by Gram-positive bacteria. Secondary graft failure (hazard ratio [HR]: 39.93; 95% confidence interval [CI]: 7.64-208.74; P <0.001), secondary poor graft function (HR: 18.07; 95% CI: 3.53 - 92.44; P <0.001), and acute gut graft-versus-host-disease (GvHD) grade II-IV (HR: 29.86; 95% CI: 10.53 - 84.68; P <0.001) were associated with the higher risk of Gram-negative post-engraftment BSIs. Overall 30-day survival after post-engraftment BSIs was 71.4%. By multivariate analysis post-engraftment BSIs (HR: 3.09; 95% CI: 1.29 - 7.38; P = 0.011), and acute gut GvHD grade II-IV (HR: 6.60; 95% CI: 2.78 - 15.68; P <0.001) were associated with the higher 180-day non-relapse mortality risk.

CONCLUSION

Gram-negative bacteria prevailed in the etiology of post-engraftment BSIs with secondary graft failure. secondary poor graft function. and acute gut GvHD being the main predisposing factors for their development. Post-engraftment BSIs were associated with the higher risk of non-relapse mortality after allo-HCT.

Incidence, etiology, risk factors and outcomes of pre-engraftment bloodstream infections after first and second allogeneic hematopoietic cell transplantation

INTRODUCTION

With increasing number of allogeneic hematopoietic cell transplantations (allo-HCT) bloodstream infections (BSI) are still among the most common and serious complications. This study aimed to analyze the incidence, etiology, risk factors, and outcomes of pre-engraftment BSI after the first and the second allo-HCT.

MATERIALS AND METHODS

This is a retrospective study of 284 patients who underwent first allo-HCT and 37 patients after the second allo-HCT at the National Research Center for Hematology in Moscow, Russia, from January 2018 till September 2021.

RESULTS

Cumulative incidence of pre-engraftment BSI was 29.9% after the first allo-HCT and 35.1% after the second (p = 0,805). Median time to the first BSI was 9 days (range 0-61 days) after the first and 16 days (range 1-28 days) after the second allo-HCT (p = 0.014). A total of 113 pathogens were isolated during 94 BSI episodes after the first allo-HCT (gram-negative bacteria 52.2%; gram-positive bacteria 47.7%). Fourteen pathogens were isolated during 14 BSI episodes after the second allo-HCT (gram-negative bacteria 50.0%; gram-positive bacteria 50.0%). The only significant difference was found in the rate of carbapenem-resistant gram-negative bacteria, which was higher after the second allo-HCT compared to the first (57.1% vs. 13.6%; p = 0.048). Mismatched unrelated donor (HR 3.01; 95% CI:1.62-5.60; p<0.0001) and haploidentical donor transplantations (HR 1.84; 95% CI:1.02-3.33; p = 0.042) were the only independent risk factors associated with the higher risk of pre-engraftment BSI. Overall 30-day survival after all BSI episodes was 94.4%,. Survival was lower after BSI during the second allo-HCT compared to the first (71.4% vs. 97.9%; p<0,0001), particularly after BSI caused by carbapenem-resistant gram-negative bacteria (25.0% vs. 100.0%; p = 0.0023). Non-relapse mortality rate at day +60 was 4.0%, and the risk was highly associated with primary graft failure (HR 9.62; 95% CI: 1.33-71.43), second allo-HCT (HR 6.80; 95% CI: 1.36-34.48), and pre-engraftment BSI caused by carbapenem-resistant gram-negative bacteria (HR 32.11; 95% CI: 4.91-210.15).

CONCLUSIONS

Pre-engraftment BSI is still a common complication after allo-HCT, particularly after mismatched unrelated and haploidentical donor transplantations. BSI incidence was slightly higher after the second allo-HCT with significantly higher rate of carbapenem-resistant BSI. Although pre-engraftment BSI would generally follow benign clinical course, survival was dramatically lower during the second allo-HCT especially after carbapenem-resistant BSI. This article is protected by copyright. All rights reserved.

In vitro activity of anidulafungin, caspofungin, fluconazole and amphotericin B against biofilms and planktonic forms of Candida species isolated from blood culture in patients with hematological malignancies

OBJECTIVE

The aim of the present study was to evaluate the in vitro susceptibility of anidulafungin, caspofungin, fluconazole and conventional amphotericin B against biofilms and planktonic forms of Candida species isolated from blood culture in patients with hematological malignancies.

MATERIALS AND METHODS

Antifungal susceptibility for planktonic forms and biofilms of Candida was determined by broth microdilution method as described by Clinical and Laboratory Standards Institute M27 methodology and metabolic XTT-based [2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] reduction assay, respectively.

RESULTS

A total of 75 Candida isolates were evaluated between 2006-2018 yy at the National Research Center for Hematology, Russia, Moscow. Biofilm production was detected in 34 (45.3%) Candida species. Antifungal susceptibility was tested for 27 common species of Candida forming biofilms (8 C.krusei, 7 C.tropicalis, 7 C.albicans, 5 C.parapsilosis). MICs below the susceptibility breakpoints were found for 100% of planktonic forms of Candida species for anidulafungin, 85.2% for caspofungin, and 66.7% for fluconazole. Amphotericin B MIC₉₀ for Candida species were less than or equal to 1 μg/ml. Candida biofilms were susceptible in vitro for both tested echinocandins, but MIC₈₀ of anidulafungin were lower compared to caspofungin. The highest MIC₈₀ against Candida biofilms was found for fluconazole (>1,024 μg/ml for all tested isolates) and for conventional amphotericin B (range 4-16 μg/ml).

CONCLUSION

The majority of Candida isolates grown as planktonic forms were susceptible to anidulafungin, caspofungin, conventional amphotericin B and fluconazole. Anidulafungin displayed higher activity against Candida biofilms than caspofungin. All Candida biofilms were resistant to fluconazole and conventional amphotericin B.

Intercontinental study on pre-engraftment and post-engraftment Gram-negative rods bacteremia in hematopoietic stem cell transplantation patients: Risk factors and association with mortality

OBJECTIVES

We present here data on Gram-negative rods bacteremia (GNRB) rates, risk factors and associated mortality.

METHODS

Data on GNRB episodes were prospectively collected in 65 allo-/67 auto-HSCT centers in 24 countries (Europe, Asia, Australia). In patients with and without GNRB, we compared: demography, underlying disease, HSCT-related data, center` fluoroquinolone prophylaxis (FQP) policy and accreditation status, and involvement of infection control team (ICT).

RESULTS

The GNRB cumulative incidence among 2818 allo-HSCT was: pre-engraftment (pre-eng-allo-HSCT), 8.4 (95% CI 7-9%), post-engraftment (post-eng-allo-HSCT), 5.8% (95%CI: 5-7%); among 3152 auto-HSCT, pre-eng-auto-HSCT, 6.6% (95%CI: 6-7%), post-eng-auto-HSCT, 0.7% (95%CI: 0.4-1.1%). GNRB, especially MDR, was associated with increased mortality. Multivariate analysis revealed the following GNRB risk factors: (a) pre-eng-allo-HSCT: south-eastern Europe center location, underlying diseases not at complete remission, and cord blood source; (b) post-eng-allo-HSCT: center location not in northwestern Europe; underlying non-malignant disease, not providing FQP and never accredited. (c) pre-eng-auto-HSCT: older age, autoimmune and malignant (vs. plasma cell) disease, and ICT absence.

CONCLUSIONS

Benefit of FQP should be explored in prospective studies. Increased GNRB risk in auto-HSCT patients transplanted for autoimmune diseases is worrying. Infection control and being accredited are possibly protective against bacteremia. GNRB are associated with increased mortality.

Matched-paired analysis of patients treated for invasive mucormycosis: standard treatment versus posaconazole new formulations (MoveOn)

BACKGROUND

First-line antifungal treatment for invasive mucormycosis (IM) consists of liposomal amphotericin B. Salvage treatment options are limited and often based on posaconazole oral suspension. With the approval of posaconazole new formulations, patients could benefit from improved pharmacokinetics, safety and tolerability.

OBJECTIVES

Our aim was to assess the effectiveness of posaconazole new formulations for IM treatment.

METHODS

We performed a case-matched analysis with proven or probable IM patients from the FungiScope® Registry. First-line posaconazole new formulations (1st-POSnew) and first-line amphotericin B plus posaconazole new formulations (1st-AMB+POSnew) cases were matched with first-line amphotericin B-based (1st-AMB) treatment controls. Salvage posaconazole new formulations (SAL-POSnew) cases were matched with salvage posaconazole oral suspension (SAL-POSsusp) controls. Each case was matched with up to three controls (based on severity, haematological/oncological malignancy, surgery and/or renal dysfunction).

RESULTS

Five patients receiving 1st-POSnew, 18 receiving 1st-AMB+POSnew and 22 receiving SAL-POSnew were identified. By day 42, a favourable response was reported for 80.0% (n = 4/5) of patients receiving 1st-POSnew, for 27.8% (n = 5/18) receiving 1st-AMB+POSnew and for 50.0% (n = 11/22) receiving SAL-POSnew. Day 42 all-cause mortality of patients receiving posaconazole new formulations was lower compared with controls [20.0% (n = 1/5) in 1st-POSnew versus 53.3% (n = 8/15) in 1st-AMB; 33.3% (n = 6/18) in 1st-AMB+POSnew versus 52.0% (n = 26/50) in 1st-AMB; and 0.0% (n = 0/22) in SAL-POSnew versus 4.4% (n = 2/45) in SAL-POSsusp].

CONCLUSIONS

Posaconazole new formulations were effective in terms of treatment response and associated mortality of IM. While posaconazole new formulations may be an alternative for treatment of IM, the limited sample size of our study calls for a cautious interpretation of these observations.

European guidelines for empirical antibacterial therapy for febrile neutropenic patients in the era of growing resistance: summary of the 2011 4th European Conference on Infections in Leukemia

Owing to increasing resistance and the limited arsenal of new antibiotics, especially against Gram-negative pathogens, carefully designed antibiotic regimens are obligatory for febrile neutropenic patients, along with effective infection control. The Expert Group of the 4(th) European Conference on Infections in Leukemia has developed guidelines for initial empirical therapy in febrile neutropenic patients, based on: i) the local resistance epidemiology; and ii) the patient's risk factors for resistant bacteria and for a complicated clinical course. An 'escalation' approach, avoiding empirical carbapenems and combinations, should be employed in patients without particular risk factors. A 'de-escalation' approach, with initial broad-spectrum antibiotics or combinations, should be used only in those patients with: i) known prior colonization or infection with resistant pathogens; or ii) complicated presentation; or iii) in centers where resistant pathogens are prevalent at the onset of febrile neutropenia. In the latter case, infection control and antibiotic stewardship also need urgent review. Modification of the initial regimen at 72-96 h should be based on the patient's clinical course and the microbiological results. Discontinuation of antibiotics after 72 h or later should be considered in neutropenic patients with fever of unknown origin who are hemodynamically stable since presentation and afebrile for at least 48 h, irrespective of neutrophil count and expected duration of neutropenia. This strategy aims to minimize the collateral damage associated with antibiotic overuse, and the further selection of resistance.

Targeted therapy against multi-resistant bacteria in leukemic and hematopoietic stem cell transplant recipients: guidelines of the 4th European Conference on Infections in Leukemia (ECIL-4, 2011)

The detection of multi-resistant bacterial pathogens, particularly those to carbapenemases, in leukemic and stem cell transplant patients forces the use of old or non-conventional agents as the only remaining treatment options. These include colistin/polymyxin B, tigecycline, fosfomycin and various anti-gram-positive agents. Data on the use of these agents in leukemic patients are scanty, with only linezolid subjected to formal trials. The Expert Group of the 4(th) European Conference on Infections in Leukemia has developed guidelines for their use in these patient populations. Targeted therapy should be based on (i) in vitro susceptibility data, (ii) knowledge of the best treatment option against the particular species or phenotype of bacteria, (iii) pharmacokinetic/pharmacodynamic data, and (iv) careful assessment of the risk-benefit balance. For infections due to resistant Gram-negative bacteria, these agents should be preferably used in combination with other agents that remain active in vitro, because of suboptimal efficacy (e.g., tigecycline) and the risk of emergent resistance (e.g., fosfomycin). The paucity of new antibacterial drugs in the near future should lead us to limit the use of these drugs to situations where no alternative exists.