Aetiology and resistance in bacteraemias among adult and paediatric haematology and cancer patients

Ciprofloxacin prophylaxis during autologous stem cell transplantation for multiple myeloma in patients with a high rate of fluoroquinolone-resistant gram-negative bacteria colonization

BACKGROUND

Ciprofloxacin prophylaxis used to be a standard precaution during autologous stem cell transplantation. Its benefit, with a high prevalence of fluoroqinolone resistance in the population, has recently been under scrutiny.

OBJECTIVE

To evaluate the impact of cessation of ciprofloxacin prophylaxis during stem cell transplantation for multiple myeloma.

PATIENTS AND METHODS

Data from 104 patients with multiple myeloma transplanted during the period from January 2013 to April 2015 were retrospectively reviewed. 67 received standard ciprofloxacin prophylaxis (group A) and 37 received no antibacterial prophylaxis (group B).

RESULTS

Febrile episodes during neutropenia, bloodstream infection (BSI) and mortality in these two cohorts were evaluated. Gram negative BSI was assessed for the colonization of quinolone-resistant gram-negative pathogens. Secondary Clostridium difficile enterocolitis presence was determined in both cohorts. There were 42 (63%), 7 (10%), and 0 febrile episodes, BSI and gram-negative BSI respectively in group A, and 34 (92%), 12 (32%), and 4 (11%) respectively in group B. The differences in the number of febrile episodes (P=0.0011) and deaths (P=0.0427) were statistically significance. Mortality was 0 and 3 (8%) in group A and group B, respectively. There was no significant difference in colonization with quinolone-resistant gram negative pathogens (25 (37%) versus 11 (30%)) between groups. The occurrence of Clostridium difficile colitis was the same in both groups.

CONCLUSION

We resumed ciprofloxacin prophylaxis for the following reasons. There was a significant reduction in febrile episodes, and consequently a sparing effect of antibiotics used for treatment of this condition. No difference in Clostridium difficile colitis occurred and the mortality rate of 8% in group B was unacceptably high.

Pulmonary Infections in Immunocompromised Hosts: Clinical

Pulmonary infections in immunocompromised patients remain a significant contributor to mortality, morbidity, and health care-associated costs in such a vulnerable patient population. Their epidemiology is changing, set forth by new trends in immunosuppressive regimens and also prophylaxis. The host characteristics, presenting clinical symptomatology, along with radiographic patterns, have also evolved. The microbiology diagnostics are now enriched with nonculture methods for better identification of the causative pathogens. Chest imaging remains the cornerstone of the initial workup. Our article will examine the new trends in epidemiology, clinical findings, and diagnostics for immunocompromised patients with pulmonary infections (transplant recipients, neutropenic hosts, HIV-infected patients, and patients with autoimmune conditions). We will also review the differential diagnosis that most of the times includes malignancies and drug or radiation-related toxicities.

Incidence, Risk Factors and Outcome of Pre-engraftment Gram-Negative Bacteremia After Allogeneic and Autologous Hematopoietic Stem Cell Transplantation: An Italian Prospective Multicenter Survey

Background

Gram-negative bacteremia (GNB) is a major cause of illness and death after hematopoietic stem cell transplantation (HSCT), and updated epidemiological investigation is advisable.

Methods

We prospectively evaluated the epidemiology of pre-engraftment GNB in 1118 allogeneic HSCTs (allo-HSCTs) and 1625 autologous HSCTs (auto-HSCTs) among 54 transplant centers during 2014 (SIGNB-GITMO-AMCLI study). Using logistic regression methods. we identified risk factors for GNB and evaluated the impact of GNB on the 4-month overall-survival after transplant.

Results

The cumulative incidence of pre-engraftment GNB was 17.3% in allo-HSCT and 9% in auto-HSCT. Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa were the most common isolates. By multivariate analysis, variables associated with GNB were a diagnosis of acute leukemia, a transplant from a HLA-mismatched donor and from cord blood, older age, and duration of severe neutropenia in allo-HSCT, and a diagnosis of lymphoma, older age, and no antibacterial prophylaxis in auto-HSCT. A pretransplant infection by a resistant pathogen was significantly associated with an increased risk of posttransplant infection by the same microorganism in allo-HSCT. Colonization by resistant gram-negative bacteria was significantly associated with an increased rate of infection by the same pathogen in both transplant procedures. GNB was independently associated with increased mortality at 4 months both in allo-HSCT (hazard ratio, 2.13; 95% confidence interval, 1.45-3.13; P <.001) and auto-HSCT (2.43; 1.22-4.84; P = .01).

Conclusions

Pre-engraftment GNB is an independent factor associated with increased mortality rate at 4 months after auto-HSCT and allo-HSCT. Previous infectious history and colonization monitoring represent major indicators of GNB.

Clinical Trials registration

NCT02088840.

Risk factors for mortality in patients with acute leukemia and bloodstream infections in the era of multiresistance

Objectives

We assess the epidemiology and risk factors for mortality of bloodstream infection (BSI) in patients with acute leukemia (AL).

Methods

Prospectively collected data of a cohort study from July 2004 to February 2016. Multivariate analyses were performed.

Results

589 episodes of BSI were documented in 357 AL patients, 55% caused by gram-positive bacteria (coagulase-negative staphylococci 35.7%, Enterococcus spp 10.8%) and 43.5% by gram-negative bacteria (E. coli 21%, PA 12%). We identified 110 (18.7%) multidrug-resistant (MDR) microorganisms, especially MDR-Pseudomonas aeruginosa (7%) and extended-spectrum beta-lactamase producing Enterobacteriaceae (7%). The 30-day mortality was 14.8%. Age (OR 3.1; 95% CI 1.7–5.7); chronic lung disease (4.8; 1.1–21.8); fatal prognosis according to McCabe index (13.9; 6.4–30.3); shock (3.8; 1.9–7.7); pulmonary infection (3.6; 1.3–9.9); and MDR-PA infections with inappropriate treatment (12.8; 4.1–40.5) were related to mortality. MDR-PA BSI was associated to prior antipseudomonal cephalosporin use (9.31; 4.38–19.79); current use of betalactams (2.01; 1.01–4.3); shock (2.63; 1.03–6.7) and pulmonary source of infection (9.6; 3.4–27.21).

Conclusions

MDR organisms were commonly isolated in BSI in AL. Inappropriate empiric antibiotic treatment for MDR-PA is the primary factor related to mortality that can be changed. New treatment strategies to improve the coverage of MDR-PA BSI should be considered in those patients with risk factors for this infection.

Empirical antimicrobial treatment in haemato-/oncological patients with neutropenic sepsis

Neutropenic sepsis in haemato-/oncological patients is a medical emergency, as infections may show a fulminant clinical course. Early differentiation between sepsis and febrile neutropenic response often proves to be challenging. To assess the severity of the illness, different tools, which are discussed in this article, are available. Once the diagnosis has been established, the correct use of early empirical antibiotic and antifungal treatment is key in improving patient survival. Therefore, profound knowledge of local resistance patterns is mandatory and carefully designed antibiotic regimens have to be established in cooperation with local microbiologists or infectious diseases specialists. In the following, identification, therapy and management of high-risk, neutropenic patients will be reviewed based on experimental and clinical studies, guidelines and reviews.

Impact of fluoroquinolone prophylaxis during neutropenia on bloodstream infection: Data from a surveillance program in 8755 patients receiving high-dose chemotherapy for haematologic malignancies between 2009 and 2014

OBJECTIVES

Antibacterial chemoprophylaxis with fluoroquinolones (FQPx) has been commonly used in cancer patients with neutropenia, but its efficacy has been challenged by the emergence of fluoroquinolone resistance.

METHODS

The impact of FQPx on bloodstream infections (BSI) during neutropenia after high-dose chemotherapy for haematologic malignancies was evaluated through a multicenter hospital infection surveillance system for the period 2009-2014.

RESULTS

Among 8755 patients (4223 allogeneic [allo-] HSCT, 3602 autologous [auto-] HSCT, 930 high-dose chemotherapy for acute leukemia [HDC]), 5302 (61%) had received FQPx. Administration of FQPx was associated with fewer Gram-negative BSI in the overall study cohort patients (4.6% vs. 7.7%, adjusted subdistribution hazard ratio [aSHR] 0.59, 95%CI 0.50-0.70), in patients with HDC (3.7% vs. 9.2%, adjusted subdistribution hazard ratio [aSHR] 0.40, 95%CI 0.22-0.70) and auto-HSCT patients (4% vs. 9%, aSHR 0.43, 95%CI 0.33-0.56). In HDC patients, FQPx was associated with a marked reduction in all-cause mortality during neutropenia (2.3% vs. 7.8%, aSHR 0.30, 95%CI 0.15-0.58). Patients receiving FQPx had significantly more BSIs due to ESBL-positive Enterobacteriacea (0.8 vs. 0.3%, RR 2.2, 95%CI 1.17-4.26). BSIs by MRSA (n = 5) and VRE (n = 11) were rare in our cohort.

CONCLUSIONS

As used in the participating centers, FQPx was associated with reduced Gram-negative BSI and improved survival among HDC patients. Among HSCT patients, the benefits were less clear. If adapted to local resistance patterns and patient characteristics, FQPx still may be useful in the management of patients with haematologic malignancies.

Clinical Impact of Pretransplant Multidrug-Resistant Gram-Negative Colonization in Autologous and Allogeneic Hematopoietic Stem Cell Transplantation

Multidrug-resistant Gram-negative bacteria (MDR-GNB) are an emerging cause of morbidity and mortality after hematopoietic stem cell transplantation (HSCT). Three-hundred forty-eight consecutive patients transplanted at our hospital from July 2012 to January 2016 were screened for a pretransplant MDR-GNB colonization and evaluated for clinical outcomes. A pretransplant MDR-GNB colonization was found in 16.9% of allo-HSCT and in 9.6% of auto-HSCT recipients. Both in auto- and in allo-HSCT, carriers of a MDR-GNB showed no significant differences in overall survival (OS), transplant-related mortality (TRM), or infection-related mortality (IRM) compared with noncarriers. OS at 2 years for carriers compared with noncarriers was 85% versus 81% (P = .262) in auto-HSCT and 50% versus 43% (P = .091) in allo-HSCT. TRM at 2 years was 14% versus 5% (P = .405) in auto-HSCT and 31% versus 25% (P = .301) in allo-HSCT. IRM at 2 years was 14% versus 2% (P = .142) in auto-HSCT and 23% versus 14% (P = .304) in allo-HSCT. In multivariate analysis, only grade III to IV acute graft-versus-host disease was an independent factor for reduced OS (P < .001) and increased TRM (P < .001) and IRM (P < .001). During the first year after transplant, we collected 73 GNB bloodstream infectious (BSI) episodes in 54 patients, 42.4% of which sustained by a MDR-GNB. Rectal swabs positivity associated with the pathogen causing subsequent MDR-GNB BSI episodes in 13 of 31 (41.9%). Overall, OS at 4 months from MDR-GNB BSI episode onset was of 67.9%, with a 14-day attributed mortality of 12.9%, not being significantly different between carriers and noncarriers (P = .207). We conclude that in this extended single-center experience, a pretransplant MDR-GNB colonization did not significantly influence OS, TRM, and IRM both in auto- and allo-HSCT settings and that MDR-GNB attributed mortality can be controlled in carriers when an early pre-emptive antimicrobial therapy is started in case of neutropenic fever.

Infectious complications after hematopoietic stem cell transplantation: current status and future perspectives in Korea

Hematopoietic stem cell transplantation (HSCT) is a treatment for hematologic malignancies, immune deficiencies, or genetic diseases, ect. Recently, the number of HSCTs performed in Korea has increased and the outcomes have improved. However, infectious complications account for most of the morbidity and mortality after HSCT. Post-HSCT infectious complications are usually classified according to the time after HSCT: pre-engraftment, immediate post-engraftment, and late post-engraftment period. In addition, the types and risk factors of infectious complications differ according to the stem cell source, donor type, conditioning intensity, region, prophylaxis strategy, and comorbidities, such as graft-versushost disease and invasive fungal infection. In this review, we summarize infectious complications after HSCT, focusing on the Korean perspectives.

Early discontinuation of empirical antibacterial therapy in febrile neutropenia: the ANTIBIOSTOP study

INTRODUCTION

Immediate empirical antibiotic therapy is mandatory in febrile chemotherapy-induced neutropenia, but its optimal duration is unclear, especially in patients with fever of unknown origin (FUO).

OBJECTIVES

The primary objective of this 20-month prospective observational study was to evaluate the feasibility and safety of short-term antibiotic treatment in afebrile or febrile patients exhibiting FUO, irrespective of their neutrophil count. The secondary objective was to describe the epidemiology of all episodes of febrile neutropenia.

METHODS

In the first phase of the study, empirical antibiotic therapy in FUO patients was stopped after 48 h of apyrexia, in accordance with European Conference on Infections in Leukaemia guidelines (n = 45). In the second phase of the study, antibiotics were stopped no later than day 5 for all FUO patients, regardless of body temperature or leukocyte count (n = 37).

RESULTS

Two hundred and thirty-eight cases of febrile neutropenia in 123 patients were included. Neither the composite endpoint (p = .11), nor each component (in-hospital mortality (p = .80), intensive care unit admission (p = 0.48), relapse of infection ≤48 h after discontinuation of antibiotics (p = .82)) differed between the two FUO groups. Violation of protocol occurred in 17/82 episodes of FUO without any major impact on statistical results. Twenty-six (57.3%) and 22 (59.5%) FUO episodes did not relapse during hospital-stay (p = 1), and nine (20%) and five (13.5%) presented another FUO, respectively. One hundred and fifty-six episodes of febrile neutropenia (65.5%) were clinically or microbiologically documented, including 85 bacteremia.

CONCLUSIONS

These results suggest that early discontinuation of empirical antibiotics in FUO is safe for afebrile neutropenic patients.

Evaluation of febrile neutropenic attacks of pediatric hematology-oncology patients

Aim

Febrile neutropenia is an important cause of mortality and morbidity in hematology-oncology patients undergoing chemotherapy. The objective of this study was to evaluate febrile neutropenic episodes in children with malignancy.

Material and Methods

Sixty-eight children who received chemotherapy for malignancy between 2010 and 2015 were retrospectively reviewed. The demographic characteristics, laboratory data, infection foci, and frequency of microorganisms grown in culture were examined. Also, the frequency of febrile neutropenic attacks was investigated according to the chemotherapy periods.

Results

Of the total 200 episodes, 81 (40.5%) were clinically documented, and 73 (36.5%) were microbiologically documented infections. Fever of unknown origin was observed in 46 (23%) episodes. The most frequently clinically documented focus were mucositis (33.4%) and pneumonia (24.7%). Blood culture was positive in 55 (75.3%) episodes of microbiologically documented infections. The most commonly isolated microorganisms in blood culture were Gram-negative bacteria (47.2%). C-reactive protein levels in microbiologically documented infections were higher than in clinically documented infections, and fever of unknown origin (p<0.05, for both). The most common underlying malignancy was acute lymphoblastic leukemia (73.5%). The highest proportions (34.6%) of febrile neutropenic episodes were observed during the reinduction period for these children. Nine (13.2%) children died of neutropenic sepsis.

Conclusions

Febrile neutropenia continues to be an important cause of mortality in pediatric patients with malignancy. C-reactive protein levels may be an indicator for predicting bacterial infection in children with febrile neutropenia without apparent focus. The most frequently isolated agents in our center were Gram-negative microorganisms. Determining the microbial flora of each center may be beneficial to improving survival rates.

A fresh look at polymicrobial bloodstream infection in cancer patients

Objectives

To assess the current incidence, clinical features, risk factors, aetiology, antimicrobial resistance and outcomes of polymicrobial bloodstream infection (PBSI) in patients with cancer.

Methods

All prospectively collected episodes of PBSI in hospitalised patients were compared with episodes of monomicrobial bloodstream infection (MBSI) between 2006 and 2015.

Results

We identified 194 (10.2%) episodes of PBSI and 1702 MBSI (89.8%). The presence of cholangitis, biliary stenting, neutropenia, corticosteroids, neutropenic enterocolitis and other abdominal infections were identified as risk factors for PBSI. Overall, Gram-negative organisms were the most frequent aetiology, but Enterococcus spp. were especially frequent causes of Gram-positive PBSI (30.8%). Multidrug-resistant (MDR) organisms were more commonly found in PBSI than in MBSI (20.6% vs 12.9%; p = 0.003). Compared to patients with MBSI, those with PBSI presented with higher early (15% vs 1.4%; p = 0.04) and overall (32% vs 20.9%; p<0.001) case-fatality rates. Risk factors for overall case-fatality were a high-risk MASCC (Multinational Association of Supportive Care in Cancer) index score, corticosteroid use, persistent bacteraemia and septic shock.

Conclusions

PBSI is a frequent complication in patients with cancer and is responsible for high mortality rates. Physicians should identify patients at risk for PBSI and provide empiric antibiotic therapy that covers the most frequent pathogens involved in these infections, including MDR strains.

Epidemiology and management of healthcare-associated bloodstream infections in non-neutropenic immunosuppressed patients: a review of the literature

Advancements in medicine have led to a considerable increase in the proportion of patients living with severe chronic diseases, malignancies, and HIV infections. Most of these conditions are associated with acquired immune-deficient states and treatment-related immunosuppression. Although infections as a result of neutropenia have long been recognized and strategies for management were developed, non-neutropenic immunosuppression has been overlooked. Recently, community-acquired infections in patients with frequent, significant exposure to healthcare settings and procedures have been classified as 'healthcare-associated infections' since they are more similar to hospital-acquired infections. Most of the non-neutropenic immunosuppressed patients have frequent contact with the healthcare system due to their chronic and severe diseases. In this review, we focus on the healthcare-associated bloodstream infections in the most common non-neutropenic immunosuppressive states and provide an update of the recent evidence for the management of these infections.

Combating blood stream infections during induction chemotherapy in children with acute myeloid leukemia: Single center results in India

Optimal management of infectious complication is the biggest challenge in children receiving chemotherapy for acute myeloid leukemia (AML). We have analyzed the data of children undergoing AML induction chemotherapy at our center from 2002 to 2016 and found that Gram-negative infections are more predominant when compared to the published literature. There also has been a surge in multidrug-resistant (MDR) infections over the last 4 years, which has increased the need for supportive care and escalated the cost of care. We have introduced certain novel methods to combat MDR sepsis and decrease mortality rates.

Impact of the Microbiota on Bacterial Infections during Cancer Treatment

Patients being treated for cancer are at high risk for infectious complications, generally due to colonizing organisms that gain access to sterile sites via disrupted epithelial barriers. There is an emerging understanding that the ability of bacterial pathogens, including multidrug-resistant organisms, to colonize and subsequently infect humans is largely dependent on protective bacterial species present in the microbiome. Thus, herein we review recent studies demonstrating strong correlations between the microbiome of the oncology patient and infections occurring during chemotherapy. An increased knowledge of the interplay between potential pathogens, protective commensals, and the host immune system may facilitate the development of novel biomarkers or therapeutics that could help ameliorate the toll that infections take during the treatment of cancer.

Complications of hematopoietic stem cell transplantation: Bacterial infections

Bacterial infections remain a common complication of hematopoietic stem cell transplantation (HSCT), especially in the pre-engraftment phase. The risk of bacterial infections is mainly related to neutropenia, mucositis, and the presence of vascular lines. Most parts of the world have witnessed a shift in epidemiology toward Gram-negative bacteria; a large proportion of which are resistant to fluoroquinolones, extended-spectrum beta-lactams, carbapenems, and in some units even colistin. Meticulous infection control practices are essential for prevention of bacterial infections in HSCT. The role of routine prophylactic antibiotics is limited in settings with high rates of bacterial resistance. If used, prophylactic antibiotics should be limited to high-risk patients, and the agents are selected based on local resistance profiles. Neutropenic fever is a medical emergency in most HSCT recipients. Prompt clinical evaluation is paramount, along with the intravenous administration of appropriate empiric antimicrobials, typically an antipseudomonal beta-lactam agent. Glycopeptides should only be considered if the patient is hemodynamically unstable or Gram-positive infection is suspected. Additional Gram-negative agents, such as colistin or aminoglycosides, may be added if extensive Gram-negative resistance is expected. To mitigate increasing bacterial resistance, empiric antibiotic regimens should be rationalized or discontinued as soon as possible.

Ultrasonography-driven combination antibiotic therapy with tigecycline significantly increases survival among patients with neutropenic enterocolitis following cytarabine-containing chemotherapy for the remission induction of acute myeloid leukemia

Neutropenic enterocolitis (NEC) is an abdominal infection reported primarily in patients with acute myeloid leukemia (AML) following chemotherapy, especially cytarabine, a notable efficacious cytotoxic agent for AML remission. Specific data regarding the impact of different cytarabine schedules and/or antibacterial regimens for NEC are sparse. The aim of the study was to identify the predictors of outcome within 30 days of NEC onset. NEC episodes were retrospectively pinpointed among 440 patients with newly diagnosed AML hospitalized in our Institution, over a 10‐year period, for receiving chemotherapy protocols with 100–6000 mg/m² daily of cytarabine. Two subgroups, survivors versus nonsurvivors, were compared by using logistic regression analysis. NEC was documented in 100 of 420 (23.8%) analyzed patients: 42.5% had received high‐dose cytarabine, whereas 19% and 15% intermediate‐dose and standard‐dose cytarabine, respectively (P < 0.001). The 30‐day NEC attributable mortality rate was 23%. In univariate analysis, antileukemic protocols containing robust dosages of cytarabine were significantly associated with high mortality (P < 0.001); whereas, standard‐dose cytarabine and prompt initiation (at the ultrasonographic appearance of intestinal mural thickening) of NEC therapy with antibiotic combinations including tigecycline were significantly associated with low mortality. In multivariate analysis, high‐dose cytarabine‐containing chemotherapy was the independent predictor of poor outcome (odds ratio [OR]: 0.109; 95% confidence interval [CI]: 0.032–0.364; P < 0.001), whereas ultrasonography‐driven NEC therapy with antibiotic regimens including tigecycline was associated with a favorable outcome (OR: 13.161; 95% CI: 1.587–109.17; P = 0.017). Chemotherapy schedules with robust dosages of cytarabine for AML remission are associated with a high rate of NEC incidence and attributable. Vigorous antibacterial therapy, triggered off pathologic ultrasonographic findings, with drug combinations which have broad antimicrobial coverage and good gut penetration, specifically those also including tigecycline, may be effective in improving 30‐day survival rate after NEC onset.

Current use and potential role of procalcitonin in the diagnostic work up and follow up of febrile neutropenia in hematological patients

INTRODUCTION

Febrile neutropenia (FN) represents a life-threatening complication in hematological malignancies. Its etiology is most often due to infections even though FN of other origins, such as tumor-related fever and non-infectious inflammation, should rapidly be ruled out. Initially, C-reactive protein and, more recently, procalcitonin (PCT) have been proposed as useful biomarkers for differential diagnosis. PCT was shown to be a good biomarker of bacterial infections and their clinical outcomes. Definition of standard cut-offs and design of PCT-guided treatment protocols remain however to be defined. Areas covered: In this review, highlights on the current clinical use of PCT and its potential role as a diagnostic tool have been discussed by a panel of physicians from different areas of expertise. We provide current clinical evidence that PCT has been shown to be a reliable biomarker to differentiate fever of bacterial origin from other causes. Moreover, the Authors convened to a round-table to discuss their 'real-life experience' and offer their recommendations by a Delphi survey. Expert commentary: PCT has an important clinical role in FN. Issues such as the validation of a specific decision algorithm that includes PCT to monitor antibiotic choice and treatment duration will be addressed in prospective studies.

Good tolerability of high dose colistin-based therapy in patients with haematological malignancies

PURPOSE

Colistin is usually the only drug fully active against multi-drug resistant Gram-negative bacteria, but its nephrotoxicity might limit its use. Recent pharmacokinetic/pharmacodynamic data suggest that high dose of colistin, preceded by a loading dose, are needed to maximize its antibacterial effect. The aim of this study was to determine the safety of high doses colistin, in haematology population.

METHODS

A retrospective review of haematology patients who received high dose colistin-based therapy in years 2011-2016 was performed. Nephrotoxicity was assessed using RIFLE criteria.

RESULTS

Thirty patients who received 38 courses of colistin were included in the study. Colistin was always administered together with other antibiotics. Colistin was well tolerated, with one case of neurological toxicity and one of cutaneous reaction. There were 22 (58%) treatment cycles without any nephrotoxicity, even though during 16 of these cycles other nephrotoxic drugs were administered. Severe (injury or failure) renal toxicity occurred during 6 (16%) treatment courses, requiring colistin discontinuation in 2 patients and colistin dose reduction in 1. Poorer renal function at baseline and younger age were the only variables associated with increased renal toxicity (p = 0.011 and p = 0.031, respectively). Overall mortality was 18% (7/38) and 29% (11/38) at 7 and 30 days after the treatment onset.

CONCLUSIONS

In adult haematology population, high dose colistin therapy is safe and efficacious, despite high frequency of concomitant nephrotoxic treatment.

Bacterial bloodstream infections in the allogeneic hematopoietic cell transplant patient: new considerations for a persistent nemesis

Bacterial bloodstream infections (BSI) cause significant transplant-related morbidity and mortality following allogeneic hematopoietic cell transplantation (allo-HCT). This manuscript reviews the risk factors for and the bacterial pathogens causing BSIs in allo-HCT recipients in the contemporary transplant period. In addition, it offers insight into emerging resistant pathogens and reviews clinical management considerations to treat and strategies to prevent BSIs in allo-HCT patients.

Antibacterial Resistance in Patients with Hematopoietic Stem Cell Transplantation

Recipients of hematopoietic stem cell transplantation (HSCT) are at substantial risk of bacterial, fungal, viral, and parasitic infections depending on the time elapsed since transplantation, presence of graft-versus-host disease (GVHD), and the degree of immunosuppression. Infectious complications in HSCT recipients are associated with high morbidity and mortality. Bacterial infections constitute the major cause of infectious complications, especially in the early post-transplant period. The emergence of antibacterial resistance complicates the management of bacterial infections in this patient group. Multidrug-resistant bacterial infections in this group of patients have attracted considerable interest and may lead to significant morbidity and mortality. Empirical antibacterial therapy in patients with HSCT and febrile neutropenia has a critical role for survival and should be based on local epidemiology. This review attempts to provide an overview of risk factors and epidemiology of emerging resistant bacterial infections and their management in HSCT recipients.

Risk-stratification management of febrile neutropenia in pediatric hematology-oncology patients: Results of a French nationwide survey

BACKGROUND

In 2012, new international guidelines for children with chemotherapy-induced febrile neutropenia (FN) were issued, recommending reduced-intensity management strategy based on stratification of infectious risks. Some studies have highlighted practice disparities in different countries and within the same country. Our aim was to assess the current management strategies for the treatment of chemotherapy-induced FN in children in France.

PROCEDURE

This survey of all French pediatric oncology-hematology reference centers (n = 30) in late 2012 and early 2013 sent a standardized questionnaire to each center inquiring about their definition of an FN episode, its initial empiric treatment and ongoing management, use of management stratified by risk, and any criteria used for the risk assessment. Each center's management protocol was also analyzed.

RESULTS

All French reference centers participated in this survey, completing 88% of the questionnaire items. Definitions of both fever and neutropenia varied between centers. Ten centers used a risk-stratification strategy for initial management. In all, 42 probabilistic first-line antibiotic treatments were identified. After 48 hr of apyrexia, 17 units applied different forms of step-down therapy.

CONCLUSIONS

Most French centers already offered some form of reduced-intensity or step-down therapy, although they differed substantially in their management of FN episodes. Risk stratification with validated tools is essential to facilitate the implementation of the international recommendations, which would ultimately help to standardize practices in France.

Selected Topics in Aerobic Bacteriology

Aerobic Gram-positive and Gram-negative bacteria can be important pathogens in the immunocompromised host. These bacteria can be found in many environments, as part of the normal microbiota of the human host and animals, in soil and water, on plants, on fomites in the hospital, and on hospital equipment. This review provides information from relevant studies about what are the most common aerobic bacteria associated with patients who have cancer and/or are being treated for it, or who have other diseases which lead to immunodeficiencies, such as HIV, multiple myeloma, aplastic anemia, chronic diseases, and aging. A discussion of the appropriate laboratory tests needed for diagnosis of aerobic infections and information about antibiotics and susceptibility testing are also included.

Bacterial infections in pediatric hematopoietic stem cell transplantation recipients: incidence, epidemiology, and spectrum of pathogens: report of the Polish Pediatric Group for Hematopoietic Stem Cell Transplantation

BACKGROUND

Infectious complications are a significant cause of hematopoietic stem cell transplantation (HSCT) failure, especially allogeneic HSCT (allo-HSCT) because of delayed immune reconstitution and graft-versus-host disease (GVHD) occurrence. Identifying the factors responsible for bacterial infections (BI) in patients undergoing HSCT will provide much more effective empirical antimicrobial treatment in this group of patients.

OBJECTIVE

The aim of this study was to evaluate the epidemiology and profile of BI in patients after HSCT in 5 centers of the Polish Pediatric Group for Hematopoietic Stem Cell Transplantation in 2012-2013.

PATIENTS AND METHODS

In 308 HSCT recipients, we retrospectively analyzed 273 episodes of BI in 113 (36.7%) children aged 0.02-22 years (median age: 7 years), 92 after allo-HSCT and 22 after autologous HSCT (auto-HSCT). We assessed incidence of BI in different HSCT types by calculating the Index of Bacterial Infection (IBI) as a ratio of patients with at least 1 BI to all patients who underwent this type of HSCT in the analyzed period. We assessed the profile of BI with particular emphasis on multidrug-resistant organisms, and impact of underlying disease and of graft-versus-host disease on BI episodes.

RESULTS

In the studied group, 273 episodes of BI were diagnosed, including 237 episodes after allo-HSCT and 36 after auto-HSCT. Among allo-HSCT recipients diagnosed with at least 1 BI, the IBI was 0.4 (matched sibling donor-HSCT 0.3; matched donor-HSCT 0.4; mismatched unrelated donor [MMUD]-HSCT 0.8; P = 0.027) and after auto-HSCT 0.3 per 1 transplanted patient. In patient after allo-HSCT because of myelo- or lymphoproliferative diseases and bone marrow failures, the major cause of infections was Enterobacteriaceae, while gram-positive bacteria predominated in the group with primary immunodeficiencies. In all patients after auto-HSCT, the dominant pathogen of BI were Enterobacteriaceae (P = 0.011). Time from each type of HSCT to infection caused by different pathogens did not differ significantly.

CONCLUSIONS

The risk of BI does not depend on the underlying disease, but only on HSCT donor type and is the highest after MMUD-HSCT procedure. The profile of BI depends on the underlying disease and HSCT donor type, but does not depend on the occurrence of acute GVHD. Gram-negative bacteria predominated in patients with myelo- and lymphoproliferative diseases, while in patients with primary immunodeficiencies gram-positive strains were predominant.

Patterns of infection and infection-related mortality in patients with steroid-refractory acute graft versus host disease

This study aimed to characterize the incidence, etiology and outcome of infectious episodes in patients with steroid refractory acute GvHD (SR-GvHD). The cohort included 127 adults treated with inolimomab (77%) or etanercept (23%) owing to acute 2-4 SR-GvHD, with a response rate of 43% on day +30 and a 4-year survival of 15%. The 1-year cumulative incidences of bacterial, CMV and invasive fungal infection were 74%, 65% and 14%, respectively. A high rate (37%) of enterococcal infections was observed. Twenty patients (15.7%) developed BK virus-hemorrhagic cystitis and five percent had an EBV reactivation with only one case of PTLD. One-third of long-term survivors developed pneumonia by a community respiratory virus and/or encapsulated bacteria, mostly associated with chronic GvHD. Infections were an important cause of non-relapse mortality, with a 4-year incidence of 46%. In multivariate analysis, use of rituximab in the 6 months before SCT (hazard ratio; HR 4.2; 95% confidence interval; CI 1.1-16.3), severe infection before SR-GvHD onset (HR 5.8; 95% CI 1.3-26.3) and a baseline C-reactive protein >15 UI/mL (HR 2.9; 95% CI 1.1-8.5) were associated with infection-related mortality. High rates of opportunistic infections with remarkable mortality warrant further efforts to optimize long-term outcomes after SR-GvHD.

Increase in Antibiotic-Resistant Gram-Negative Bacterial Infections in Febrile Neutropenic Children

BACKGROUND

The incidence of bacteremia caused by Gram-negative bacteria has increased recently in febrile neutropenic patients with the increase of antibiotic-resistant Gram-negative bacterial infections. This study aimed to identify the distribution of causative bacteria and the proportion of antibiotic-resistant bacteria in bacteremia diagnosed in febrile neutropenic children.

MATERIALS AND METHODS

The medical records of febrile neutropenic children diagnosed with bacteremia between 2010 and 2014 were retrospectively reviewed. The causative bacteria and proportion of antibiotic-resistant bacteria were investigated and compared yearly during the study period. The clinical impact of antibiotic-resistant bacterial infections was also determined.

RESULTS

A total of 336 bacteremia episodes were identified. During the entire study period, 181 (53.9%) and 155 (46.1%) episodes were caused by Gram-negative and Gram-positive bacteria, respectively. Viridans streptococci (25.9%), Klebsiella spp. (16.7%), and Escherichia coli (16.4%) were the most frequent causative bacteria. The overall distribution of causative bacteria was not significantly different annually. Antibiotic-resistant bacteria were identified in 85 (25.3%) episodes, and the proportion of antibiotic-resistant bacteria was not significantly different annually. Extended-spectrum β-lactamase-producing E. coli and Klebsiella spp. were most common among antibiotic-resistant Gram-negative bacteria, and they accounted for 30.6% (n = 34) of the identified E. coli and K. pneumoniae. Methicillin-resistant coagulase-negative staphylococci were most common among antibiotic-resistant Gram-positive bacteria, and it accounted for 88.5% (n = 23) of the identified coagulase-negative staphylococci. Antibiotic-resistant bacterial infections, especially antibiotic-resistant Gram-negative bacterial infections, caused significantly higher mortality due to bacteremia compared with non-antibiotic-resistant bacterial infections (P < 0.001).

CONCLUSION

Recently, Gram-negative bacteria caused more bacteremia cases than Gram-positive bacteria in febrile neutropenic children, and antibiotic-resistant Gram-negative bacterial infections increased. Antibiotic-resistant bacterial infections caused poorer prognosis compared with non-antibiotic-resistant bacterial infections, and therefore, continuous surveillance for changing epidemiology of antibiotic-resistant bacterial infections and their clinical impact is necessary.

Clinical research in febrile neutropenia in cancer patients: Past achievements and perspectives for the future

Febrile neutropenia (FN) is responsible for significant morbidity and mortality. It can also be the reason for delaying or changing potentially effective treatments and generates substantial costs. It has been recognized for more than 50 years that empirical administration of broad spectrum antibiotics to patients with FN was associated with much improved outcomes; that has become a paradigm of management. Increase in the incidence of microorganisms resistant to many antibiotics represents a challenge for the empirical antimicrobial treatment and is a reason why antibiotics should not be used for the prevention of neutropenia. Prevention of neutropenia is best performed with the use of granulocyte colony-stimulating factors (G-CSFs). Prophylactic administration of G-CSFs significantly reduces the risk of developing FN and consequently the complications linked to that condition; moreover, the administration of G-CSF is associated with few complications, most of which are not severe. The most common reason for not using G-CSF as a prophylaxis of FN is the relatively high cost. If FN occurs, in spite of prophylaxis, empirical therapy with broad spectrum antibiotics is mandatory. However it should be adjusted to the risk of complications as established by reliable predictive instruments such as the Multinational Association for Supportive Care in Cancer. Patients predicted at a low level of risk of serious complications, can generally be treated with orally administered antibiotics and as out-patients. Patients with a high risk of complications should be hospitalized and treated intravenously. A short period of time between the onset of FN and beginning of empirical therapy is crucial in those patients. Persisting fever in spite of antimicrobial therapy in neutropenic patients requires a special diagnostic attention, since invasive fungal infection is a possible cause for it and might require the use of empirical antifungal therapy.

Clinical features, aetiology and outcome of bacteraemic pneumonia in neutropenic cancer patients

BACKGROUND AND OBJECTIVE

We aimed to assess the clinical features, aetiology and outcomes of bacteraemic pneumonia in neutropenic cancer patients (NCP) in the current era of increasing antimicrobial resistance.

METHODS

All episodes of bacteraemia occurring in hospitalized patients with cancer, including haematopoietic stem cell transplant recipients, from January 2006 to April 2015 were included.

RESULTS

We identified 1723 episodes of bacteraemia, of which 795 occurred in neutropenic patients with cancer, and among them, 55 episodes were identified as bacteraemic pneumonia. The most frequent causative agents were Pseudomonas aeruginosa (39.6%), Streptococcus pneumoniae (20.6%) and Escherichia coli (8.6%). Among the Gram-negative organisms, 12.8% were multidrug resistant (MDR). Eleven patients (20%) required admission to intensive care, and eight (14.8%) underwent invasive mechanical ventilation. Nine patients (16.3%) received inadequate empirical antibiotic therapy, of whom six (66.6%) died; eight of these nine patients had pneumonia caused by resistant microorganisms. The early (48 h) case-fatality rate was 24% and the overall (30 day) case-fatality rate was 46.2%.

CONCLUSION

Bacteraemic pneumonia is a frequent complication among NCP and is mainly caused by P. aeruginosa and S. pneumoniae. The emergence of MDR organisms is of special concern. Despite the improvement in the management of cancer patients, case-fatality rates of NCP with bacteraemic pneumonia remain high. Urgent assessment is needed to identify a better approach for the management and support of these patients.

Multidrug-resistant bacteria in hematology patients: emerging threats

Multidrug-resistant (MDR) bacteria, particularly Gram negatives, such as Enterobacteriaceae resistant to third-generation cephalosporins or carbapenems and MDR Pseudomonas aeruginosa, are increasingly frequent in hematology patients. The prevalence of different resistant species varies significantly between centers. Thus, the knowledge of local epidemiology is mandatory for deciding the most appr-opriate management protocols. In the era of increasing antibiotic resistance, empirical therapy of febrile neutropenia should be individualized. A de-escalation approach is recommended in case of severe clinical presentation in patients who are at high risk for infection with a resistant strain. Targeted therapy of an MDR Gram negative usually calls for a combination treatment, although no large randomized trials exist in this setting. Infection control measures are the cornerstone of limiting the spread of MDR pathogens in hematology units.

Prospective Evaluation of Infection Episodes in Cancer Patients in a Tertiary Care Academic Center: Microbiological Features and Risk Factors for Mortality

OBJECTIVE

We aimed to determine the frequency, type, and etiology of infections and the risk factors for infections and mortality in hospitalized cancer patients.

MATERIALS AND METHODS

We prospectively enrolled adult cancer patients hospitalized in the internal medicine wards of a tertiary care academic center between January and August 2004. Patients were followed during their hospitalization periods for neutropenia, infections, culture results, and mortality.

RESULTS

We followed 473 cancer patients with 818 hospitalization episodes and 384 infection episodes in total. Seventy-nine percent of the infections were nosocomial, and febrile neutropenia (FN) was observed in 196 (51%) of the infection episodes. Bacteremia was found in 29% of FN episodes and in 8% of nonneutropenic patients. Gram-positive bacteria were the leading cause of bacteremia in both neutropenic and nonneutropenic cases (70% and 58%, respectively). Presence of an indwelling central catheter increased bacteremia risk by 3-fold. The overall mortality rate was 17%, whereas 34% of the patients with bloodstream infections died. Presence of bacteremia and advanced disease stage increased overall mortality by 6.1-fold and 3.7-fold, respectively.

CONCLUSION

Nearly half of the cancer patients developed an infection during their hospital stays, with gram-positive bacteria being the predominant etiologic microorganisms. This demonstrates the changing trends in infections considering that, until 2004, gram-negative bacteria were the most predominant microorganisms among cancer patients in our institute.

Bloodstream infections in neutropenic cancer patients: A practical update

Bloodstream infections (BSI) are among the most frequent complications in neutropenic cancer patients and, if caused by Gram-negative rods, are associated with high mortality. Thus, fever during neutropenia warrants prompt empirical antibiotic therapy which should be active against the most frequent Gram-negatives. In the last decade, there has been a worldwide increase in multidrug resistant (MDR) strains. In these cases, the traditional choices such as oral therapy, ceftazidime, cefepime, piperacillin-tazobactam, or even carbapenems, might be ineffective. Therefore novel de-escalation approach has been proposed for patients who are at high risk for infections due to MDR bacteria. It consists of starting antibiotics which cover the most probable resistant strain but it is narrowed down after 72 hours if no MDR pathogen is isolated. With increasing bacterial resistance, the benefit of fluoroquinolone prophylaxis during prolonged neutropenia remains to be confirmed. Antibiotic stewardship and infection control programs are mandatory in every cancer center.

Epidemiology of antimicrobial resistance in bloodstream infections

Antimicrobial resistance in bacterial pathogens is a worldwide challenge leading high morbidity and mortality in clinical settings. Multidrug resistant patterns in gram-positive and -negative bacteria have resulted in difficult-to-treat or even untreatable infections with conventional antimicrobials. Since the early identification of causative microorganisms and their antimicrobial susceptibility patterns in patients with bacteremia and other serious infections is lacking in many healthcare institutions, broad spectrum antibiotics are liberally and mostly unnecessarily used. Such practice has, in turn, caused dramatic increases in emerging resistance and when coupled with poor practice of infection control, resistant bacteria can easily be disseminated to the other patients and the environment. Thus, availability of updated epidemiological data on antimicrobial resistance in frequently encountered bacterial pathogens will be useful not only for deciding on empirical treatment strategies, but also devising an effective antimicrobial stewardship program in hospitals.

Fecal Microbiota Transplantation Inhibits Multidrug-Resistant Gut Pathogens: Preliminary Report Performed in an Immunocompromised Host

Colonization of the gastrointestinal tract with multidrug-resistant (MDR) bacteria is a consequence of gut dysbiosis. We describe the successful utilization of fecal microbiota transplantation to inhibit Klebsiella pneumoniae MBL⁺ and Escherichia coli ESBL⁺ gut colonization in the immunocompromised host as a novel tool in the battle against MDR microorganisms.

ClinicalTrials.gov identifier NCT02461199.

Viridans Group Streptococcal Infections in Children After Chemotherapy or Stem Cell Transplantation: A 10-year Review From a Tertiary Pediatric Hospital

Viridans Group Streptococci (VGS) are associated with high mortality rates in febrile neutropenia; yet there are no recent European pediatric studies to inform antimicrobial therapy. The aim of this study was to describe the characteristics, outcome, and resistance patterns of children with VGS bacteremia (VGSB) undergoing treatment of malignancy or hematopoietic stem cell transplant. Patients aged 0 to 18 years, admitted to a tertiary pediatric hemato-oncology center with VGSB, from 2003 to 2013, were included in the study. All data were collected retrospectively from medical records. A total of 54 bacteremic episodes occurred in 46 patients. The most common underlying diagnosis was relapsed acute lymphoblastic leukemia. Streptococcus mitis was the most frequent organism. A total of 30% of isolates were resistant to penicillin and 100% sensitive to vancomycin. There were 8 episodes (14.8%) of Viridans Group Streptococcal Shock Syndrome; 6 resulted in admission to intensive care and 3 of these patients died of multiorgan failure. The potentially fatal nature of VGSB is confirmed. The high risk in relapsed acute lymphoblastic leukemia is of note. Research is needed to develop risk-stratification scores that identify children at risk of Viridans Group Streptococcal Shock Syndrome to guide empirical antimicrobial therapy in febrile neutropenia.

Ceftaroline activity tested against viridans group streptococci from US hospitals

A total of 840 clinically relevant viridans group streptococci (VGS) isolates (1/patient episode) were collected from 71 US medical centers in 2013-2014. These organisms were tested for susceptibility by reference broth microdilution methods against ceftaroline and selected comparator agents. All isolates were speciated by matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF) mass spectrometry and were primarily from skin/soft tissue (32.6%) and bloodstream (32.3%) infections. Ceftaroline was highly active against all VGS species/groups with MIC50 and MIC90 values ranging from ≤0.015 to 0.03μg/mL and ≤0.015 to 0.06μg/mL, respectively. The highest ceftaroline MIC value was only 0.5μg/mL (0.5% of strains) and ceftaroline (MIC50/90, 0.03/0.06μg/mL) was 8-fold more active than ceftriaxone (MIC50/90, 0.25/0.5μg/mL). The VGS groups most susceptible to ceftaroline were Streptococcus mutans and Streptococcus bovis (MIC90, ≤0.015μg/mL), whereas the highest ceftaroline MIC values were observed among Streptococcus mitis and Streptococcus sanguinis groups. In summary, ceftaroline exhibited potent in vitro activity against VGS, including many uncommonly isolated species/groups for which very limited susceptibility information is currently available to guide therapy.

Antibiotic susceptibility of Gram-negatives isolated from bacteremia in children with cancer. Implications for empirical therapy of febrile neutropenia

BACKGROUND

Monotherapy is recommended as the first choice for initial empirical therapy of febrile neutropenia, but local epidemiological and antibiotic susceptibility data are now considered pivotal to design a correct management strategy.

AIM

To evaluate the proportion of Gram-negative rods isolated in bloodstream infections in children with cancer resistant to antibiotics recommended for this indication.

MATERIALS & METHODS

The in vitro susceptibility to ceftazidime, piperacillin-tazobactam, meropenem and amikacin of Gram-negatives isolated in bacteremic episodes in children with cancer followed at the Istituto "Giannina Gaslini", Genoa, Italy in the period of 2001-2013 was retrospectively analyzed using the definitions recommended by EUCAST in 2014. Data were analyzed for any single drug and to the combination of amikacin with each β-lactam. The combination was considered effective in absence of concomitant resistance to both drugs, and not evaluated by means of in vitro analysis of antibiotic combinations (e.g., checkerboard).

RESULTS

A total of 263 strains were evaluated: 27% were resistant to piperacillin-tazobactam, 23% to ceftazidime, 12% to meropenem and 13% to amikacin. Concomitant resistance to β-lactam and amikacin was detected in 6% of strains for piperacillin-tazobactam, 5% for ceftazidime and 5% for meropenem. During the study period there was a nonsignificant increase in the proportions of strains resistant to β-lactams indicated for monotherapy, and also increase in the resistance to combined therapies.

CONCLUSION

in an era of increasing resistance to antibiotics guideline-recommended monotherapy could be not appropriate for initial empirical therapy of febrile neutropenia. Strict local survey on etiology and antibiotic susceptibility is mandatory for a correct management of this complication in cancer patients.

Bloodstream infections in patients with solid tumors

Little information is currently available regarding bloodstream infection (BSI) in patients with solid tumors who, for a variety of reasons, are particularly predisposed to develop this condition. In this review we focus on the incidence, epidemiology, clinical features, etiology, antimicrobial resistance, and outcomes of BSI of adult cancer patients with solid tumors. Most episodes of BSI occur in non-neutropenic patients, in whom the site of primary or metastatic tumor often serves as the portal of entry. The urinary tract and the abdomen are the most frequent sources of infection, and cholangitis is the most common recurrent source of BSI. Gram-negative bacilli are becoming the leading cause of BSI in patients with solid tumors, and the rate of multidrug resistance is increasingly being recognized. The case-fatality rate in patients with solid tumors and BSI is high, especially among those with comorbidities, advanced neoplasms, corticosteroid therapy, and shock at presentation.