Antibiotic prophylaxis for patients with acute leukemia

Current progress and critical challenges to overcome in the bioinformatics of mass spectrometry-based metaproteomics

Metaproteomics is a relatively young field that has only been studied for approximately 15 years. Nevertheless, it has the potential to play a key role in disease research by elucidating the mechanisms of communication between the human host and the microbiome. Although it has been useful in developing an understanding of various diseases, its analytical strategies remain limited to the extended application of proteomics. The sequence databases in metaproteomics must be large because of the presence of thousands of species in a typical sample, which causes problems unique to large databases. In this review, we demonstrate the usefulness of metaproteomics in disease research through examples from several studies. Additionally, we discuss the challenges of applying metaproteomics to conventional proteomics analysis methods and introduce studies that may provide clues to the solutions. We also discuss the need for a standard false discovery rate control method for metaproteomics to replace common target-decoy search approaches in proteomics and a method to ensure the reliability of peptide spectrum match.

Challenges in Clinical Metaproteomics Highlighted by the Analysis of Acute Leukemia Patients with Gut Colonization by Multidrug-Resistant Enterobacteriaceae

The microbiome has a strong impact on human health and disease and is, therefore, increasingly studied in a clinical context. Metaproteomics is also attracting considerable attention, and such data can be efficiently generated today owing to improvements in mass spectrometry-based proteomics. As we will discuss in this study, there are still major challenges notably in data analysis that need to be overcome. Here, we analyzed 212 fecal samples from 56 hospitalized acute leukemia patients with multidrug-resistant Enterobactericeae (MRE) gut colonization using metagenomics and metaproteomics. This is one of the largest clinical metaproteomic studies to date, and the first metaproteomic study addressing the gut microbiome in MRE colonized acute leukemia patients. Based on this substantial data set, we discuss major current limitations in clinical metaproteomic data analysis to provide guidance to researchers in the field. Notably, the results show that public metagenome databases are incomplete and that sample-specific metagenomes improve results. Furthermore, biological variation is tremendous which challenges clinical study designs and argues that longitudinal measurements of individual patients are a valuable future addition to the analysis of patient cohorts.

Infection Prevention in Pediatric Oncology and Hematopoietic Stem Cell Transplant Recipients

Pediatric patients with malignancies and transplant recipients are at high risk of infection-related morbidity and mortality. Children at the highest risk for infections are those with acute myeloid leukemia (AML), relapsed acute lymphoblastic leukemia (ALL), and hematopoietic stem cell transplant recipients (HSCT). These patients are at high risk for life-threatening bacterial, viral, and fungal infections which are associated with prolonged hospital stay, poor quality of life, and increased healthcare cost and death. Recognition of risk factors which predisposes them to infections, early identification of signs and symptoms of infections, prompt diagnosis, and empiric/definitive treatment are the mainstay in reducing infection-related morbidity and mortality. Infection control and prevention programs also play a crucial role in preventing hospital-acquired infections in these immunosuppressed hosts.

Effectiveness of antibacterial prophylaxis during induction chemotherapy in children with acute lymphoblastic leukemia

BACKGROUND

Pediatric patients receiving induction chemotherapy for newly diagnosed acute lymphoblastic leukemia (ALL) are at high risk of developing life-threatening infections. We investigated whether uniform antibacterial guidelines, including mandatory antibacterial prophylaxis in afebrile patients during induction, decreases the incidence of microbiologically documented bacteremia.

METHODS

Between 2012 and 2015, 230 patients with newly diagnosed ALL (aged 1-21) were enrolled on Dana-Farber Cancer Institute ALL Consortium Protocol 11-001 (DFCI 11-001). Induction therapy, regardless of risk group, included vincristine, prednisone, doxorubicin, methotrexate, and PEG-asparaginase. Afebrile patients received fluoroquinolone prophylaxis at the initiation of induction and those presenting with fever received broad-spectrum antibiotics; antibiotics were continued until blood count recovery. Rates of documented bacteremias and fungal infections on DFCI 11-001 were compared to those on the predecessor protocol (DFCI 05-001), which included the same induction phase without antibiotic prophylaxis guidelines.

RESULTS

Sixty-six (28.7%) patients received fluoroquinolone prophylaxis, the remaining patients received broad-spectrum antibiotics. Twenty-four (36.4%) patients on prophylaxis developed fever and seven (10.6%) developed bacteremia. The overall rate of infection during induction on DFCI 11-001 was lower than on DFCl 05-001 (14.3% vs. 26.3%, P < 0.0001) due to a decreased rate of bacteremia (10.9% vs. 24.4%, P < 0.0001). The rate of fungal infections (4.8% vs. 3.6%) and induction death (0.9% vs. 2%) was not significantly different.

CONCLUSION

For children with newly diagnosed ALL, uniform antibiotic administration until blood count recovery, including fluoroquinolone prophylaxis for afebrile patients, reduced the incidence of bacteremia during the induction phase. Larger, randomized studies should be performed to confirm these findings.

Ciprofloxacin versus colistin prophylaxis during neutropenia in acute myeloid leukemia: two parallel patient cohorts treated in a single center

Patients undergoing intensive chemotherapy for acute myeloid leukemia are at high risk for bacterial infections during therapy-related neutropenia. However, the use of specific antibiotic regimens for prophylaxis in afebrile neutropenic acute myeloid leukemia patients is controversial. We report a retrospective evaluation of 172 acute myeloid leukemia patients who received 322 courses of myelosuppressive chemotherapy and had an expected duration of neutropenia of more than seven days. The patients were allocated to antibiotic prophylaxis groups and treated with colistin or ciprofloxacin through 2 different hematologic services at our hospital, as available. The infection rate was reduced from 88.6% to 74.2% through antibiotic prophylaxis (vs without prophylaxis; P=0.04). A comparison of both antibiotic drugs revealed a trend towards fewer infections associated with ciprofloxacin prophylaxis (69.2% vs 79.5% in the colistin group; P=0.07), as determined by univariate analysis. This result was confirmed through multivariate analysis (OR: 0.475, 95%CI: 0.236-0.958; P=0.041). The prophylactic agents did not differ with regard to the microbiological findings (P=0.6, not significant). Of note, the use of ciprofloxacin was significantly associated with an increased rate of infections with pathogens that are resistant to the antibiotic used for prophylaxis (79.5% vs 9.5% in the colistin group; P<0.0001). The risk factors for higher infection rates were the presence of a central venous catheter (P<0.0001), mucositis grade III/IV (P=0.0039), and induction/relapse courses (vs consolidation; P<0.0001). In conclusion, ciprofloxacin prophylaxis appears to be of particular benefit during induction and relapse chemotherapy for acute myeloid leukemia. To prevent and control drug resistance, it may be safely replaced by colistin during consolidation cycles of acute myeloid leukemia therapy.

Causative Organisms and Associated Antimicrobial Resistance in Healthcare-Associated, Central Line-Associated Bloodstream Infections From Oncology Settings, 2009-2012

BACKGROUND

Recent antimicrobial resistance data are lacking from inpatient oncology settings to guide infection prophylaxis and treatment recommendations. We describe central line-associated bloodstream infection (CLABSI) pathogens and antimicrobial resistance patterns reported from oncology locations to the Centers for Disease Control and Prevention's National Healthcare Safety Network (NHSN).

METHODS

CLABSI data reported to NHSN from 2009 to 2012 from adult inpatient oncology locations were compared to data from nononcology adult locations within the same hospitals. Pathogen profile, antimicrobial resistance rates, and CLABSI incidence rates per 1000 central line-days were calculated. CLABSI incidence rates were compared using Poisson regression.

RESULTS

During 2009-2012, 4654 CLABSIs were reported to NHSN from 299 adult oncology units. The most common organisms causing CLABSI in oncology locations were coagulase-negative staphylococci (16.9%), Escherichia coli (11.8%), and Enterococcus faecium (11.4%). Fluoroquinolone resistance was more common among E. coli CLABSI in oncology than nononcology locations (56.5% vs 41.5% of isolates tested; P < .0001) and increased significantly from 2009-2010 to 2011-2012 (49.5% vs 60.4%; P = .01). Furthermore, rates of CLABSI were significantly higher in oncology compared to nononcology locations for fluoroquinolone-resistant E. coli (rate ratio, 7.37; 95% confidence interval [CI], 6.20-8.76) and vancomycin-resistant E. faecium (rate ratio, 2.27, 95% CI, 2.03-2.53). However, resistance rates for some organisms, such as Klebsiella species and Pseudomonas aeruginosa, were lower in oncology than in nononcology locations.

CONCLUSIONS

Antimicrobial-resistant E. coli and E. faecium have become significant pathogens in oncology. Practices for antimicrobial prophylaxis and empiric antimicrobial therapy should be regularly assessed in conjunction with contemporary antimicrobial resistance data.

Prophylactic levofloxacin in pediatric neutropenic patients during autologous hematopoietic stem cell transplantation

BACKGROUND

Using fluoroquinolone prophylaxis in pediatric neutropenic patients is a controversial issue due to the concern about emergence of resistant strains in addition to the lack of pediatric studies. This study was performed to assess the effectiveness of levofloxacin prophylaxis in pediatric patients during autologous stem cell transplantation.

METHODS

This was an observational study of pediatric patients who underwent autologous stem cell transplantation, comparing patients who received levofloxacin prophylaxis to historical controls.

RESULTS

A total of 96 patients were included (46 patients in the control group and 50 patients received levofloxacin). The median duration till onset of first fever was 11 d in the control group as compared to 15 d in patients who received levofloxacin (p ≤ 0.001). The incidence of infectious complications was higher in patients without levofloxacin (4/46) than those with levofloxacin (1/50). The median duration of empirical antibiotic use was 10 d in the levofloxacin group compared with 14 d in the control group (p < 0.001).

CONCLUSION

Levofloxacin prophylaxis delayed first spike of fever, decreased the incidence of septic complications, and shortened the duration of empiric antibiotic use, but its impact on emergence of resistant organisms should be closely monitored.

Evaluation of Bloodstream Infections During Chemotherapy-Induced Febrile Neutropenia in Patients with Malignant Hematological Diseases: Single Center Experience

From year to year, it is important to get an overview of the occurrence of causative agents in febrile neutropenic patients to determine the empiric treatment. Thus our aims were to evaluate a four-year period regarding the prevalence of bloodstream infections and the most important causative agents. During this period, 1,361 patients were treated in our hematology ward because of various hematological disorders. 812 febrile episodes were recorded in 469 patients. At that time, 3,714 blood culture (BC) bottles were sent for microbiological investigations, 759 of them gave positive signal. From the majority of positive blood culture bottles (67.1%), Gram-positive bacteria, mainly coagulase-negative staphylococci (CNS), were grown. Gram-negative bacteria were isolated from 32.9% of the positive blood culture bottles, in these cases the leading pathogen was Escherichia coli. The high prevalence of CNS was attributed to mainly contamination, while lower positivity rate for Gram-negative bacteria was associated with the use of broad-spectrum empiric antibiotic treatment.

Role of antimicrobial prophylaxis during treatment of adults with acute leukemia

Patients with acute leukemia (AL) are at high risk for developing bacterial, viral and fungal infections during chemotherapy. Because these infections cause considerable morbidity and mortality, prevention is attractive. In recent decades, several trials have established the benefit of prophylactic antimicrobials in patients with AL. Administration of prophylactic fluoroquinolone, acyclovir and triazole is recommended in neutropenic patients with AL by both the USA and European national guidelines. The potential for antimicrobial resistance as a long-term consequence of prophylaxis, however, is a concern. The recent development of nonculture-based diagnostic tests for invasive fungal infections has made early diagnosis and targeted treatment a promising future strategy as an alternative to mold-active prophylaxis.

Prevention of bacterial infection in pediatric oncology: what do we know, what can we learn?

Bacterial sepsis continues to be a leading cause of morbidity and toxic death in children receiving intensive therapy for cancer. Empiric therapy for suspected infections and treatment of documented infections are well-established standards of care. The routine use of prophylactic strategies is much less common in pediatric oncology. This paper will review the current literature on the use and risks of antimicrobial prophylaxis as well as non-pharmacological methods for infection prevention and will address areas in need of further research.

Use of antibacterial prophylaxis for patients with neutropenia. Australian Consensus Guidelines 2011 Steering Committee

The use of oral prophylactic antibiotics in patients with neutropenia is controversial and not recommended by this group because of a lack of evidence showing a reduction in mortality and concerns that such practice promotes antimicrobial resistance. Recent evidence has demonstrated non-significant but consistent, improvement in all-cause mortality when fluoroquinolones (FQs) are used as primary prophylaxis. However, the consensus was that this evidence was not strong enough to recommend prophylaxis. The evidence base for FQ prophylaxis is presented alongside current consensus opinion to guide the appropriate and judicious use of these agents. Due consideration is given to patient risk, as it pertains to specific patient populations, as well as the net effect on selective pressure from antibiotics if FQ prophylaxis is routinely used in a target population. The potential costs and consequences of emerging FQ resistance, particularly among Escherichia coli, Clostridium difficile and Gram-positive organisms, are considered. As FQ prophylaxis has been advocated in some chemotherapy protocols, specific regard is given to whether FQ prophylaxis should be used to support these regimens. The group also provides recommendations for monitoring and surveillance of emerging resistance in those centres that have adopted FQ prophylaxis.

Invasive aspergillosis osteomyelitis in children--a case report and review of the literature

Immunocompromised patients are at high risk of secondary infection associated with high morbidity. In children these complications include fungal osteomyelitis due to continuous infiltration or hematogenous spread. The case of a 4-year-old boy is presented who developed lumbalgia and thigh pain during ongoing chemotherapy for acute lymphatic leukemia. MRI revealed infarct-like lesions in the femur and L5 vertebra, which were biopsied. The histologic diagnosis was consistent with angioinvasive aspergillosis. A multifocal osseous presentation has rarely been described in children and an overview of the literature is presented. Invasive aspergillosis is a rare complication to be considered in children with MRI-detected bony lesions of infarct-like appearance.

Decreased incidence of febrile episodes with antibiotic prophylaxis in the treatment of decitabine for myelodysplastic syndrome

We analyzed the role of antibiotic prophylaxis during decitabine treatment for MDS. The primary endpoint was the incidence of febrile episodes. The total number of decitabine cycles given to 28 patients was 131, and febrile episodes occurred in 15 cycles (11.5%). Antibiotic prophylaxis was orally administered in 95 cycles (72.5%). Febrile episodes were significantly less frequent among patients who received antibiotic prophylaxis (7.4%) than in those without prophylaxis (22.2%) (P=0.017). In conclusion, antibiotic prophylaxis reduced the incidence of febrile episodes in patients who received decitabine treatment for MDS, especially at earlier cycles and in the presence of severe cytopenia.