Current trends in the epidemiology of nosocomial bloodstream infections in patients with hematological malignancies and solid neoplasms in hospitals in the United States

Prevalence and impact of multidrug-resistant bacteria in solid cancer patients with bloodstream infection: a 25-year trend analysis

The study aimed to describe the epidemiology of multidrug-resistant (MDR) bacteria among solid cancer (SC) patients with bloodstream infections (BSIs), evaluating inappropriate empiric antibiotic treatment (IEAT) use and mortality trends over a 25-year period. All BSI occurrences in adult SC patients at a university hospital were analyzed across five distinct five-year intervals. MDR bacteria were classified as extended-spectrum beta-lactamases (ESBL)-producing and/or Carbapenem-resistant Enterobacterales, non-fermenting Gram-negative bacilli (GNB) resistant to at least three antibiotic classes, methicillin-resistant Staphylococcus aureus (MRSA), and Vancomycin-resistant Enterococci. A multivariate regression model identified the risk factors for MDR BSI. Of 6,117 BSI episodes, Gram-negative bacilli (GNB) constituted 60.4% (3,695/6,117), being the most common are Escherichia coli with 26.8% (1,637/6,117), Klebsiella spp. with 12.4% (760/6,117), and Pseudomonas aeruginosa with 8.6% (525/6,117). MDR-GNB accounted for 644 episodes (84.8% of MDR or 644/759), predominantly ESBL-producing strains (71.1% or 540/759), which escalated significantly over time. IEAT was administered in 24.8% of episodes, mainly in MDR BSI, and was associated with higher mortality (22.9% vs. 14%, P < 0.001). Independent factors for MDR BSI were prior antibiotic use [odds ratio (OR) 2.93, confidence interval (CI) 2.34-3.67], BSI during antibiotic treatment (OR 1.46, CI 1.18-1.81), biliary (OR 1.84, CI 1.34-2.52) or urinary source (OR 1.86, CI 1.43-2.43), admission period (OR) 1.28, CI 1.18-1.38, and community-acquired infection (OR 0.57, CI 0.39-0.82). The study showed an increase in MDR-GNB among SC patients with BSI. A quarter received IEAT, which was linked to increased mortality. Improving risk assessment for MDR infections and the judicious prescription of empiric antibiotics are crucial for better outcomes.

IMPORTANCE

Multidrug-resistant (MDR) bacteria pose a global public health threat as they are more challenging to treat, and they are on the rise. Solid cancer patients are often immunocompromised due to their disease and cancer treatments, making them more susceptible to infections. Understanding the changes and trends in bloodstream infections in solid cancer patients is crucial, to help physicians make informed decisions about appropriate antibiotic therapies, manage infections in this vulnerable population, and prevent infection. Solid cancer patients often require intensive and prolonged treatments, including surgery, chemotherapy, and radiation therapy. Infections can complicate these treatments, leading to treatment delays, increased healthcare costs, and poorer patient outcomes. Investigating new strategies to combat MDR infections and researching novel antibiotics in these patients is of paramount importance to avoid these negative impacts.

Shifting trends in bloodstream infection-causing microorganisms and their clinical impact in patients with haematologic malignancies in South Korea: A propensity score-matched study

BACKGROUND

This study aimed to identify recent trends in the epidemiology of bloodstream infection (BSI)-causing microorganisms among patients with haematologic malignancies (HMs) between 2011 and 2021, and to determine their impact on patient outcomes.

METHODS

This retrospective study included 6792 patients with HMs, of whom 1308 (19.3%) developed BSI within 1 y of diagnosis. The incidence of BSI-causing microorganisms was determined, and a propensity score-matched study was performed to identify risk factors for 28-d all-cause mortality in patients with HM.

RESULTS

A total of 6792 patients with HMs were enrolled. The cumulative incidence of BSI and neutropenia was significantly higher in the acute myeloid leukaemia and acute lymphoblastic leukaemia groups compared to other groups, and neutropenia and type of HMs were risk factors for the development of BSI. The annual incidence of coagulase-negative staphylococci (CoNS)-BSI decreased significantly (P < 0.001), whereas Klebsiella pneumoniae-BSI increased (P = 0.01). Carbapenem nonsusceptibility rates in K. pneumoniae isolates increased from 0.0% to 76.5% (P < 0.001). BSI caused by K. pneumoniae (adjusted odds ratio 2.17; 95% confidence interval 1.12-4.21) was associated with higher 28-d all-cause mortality compared to that caused by CoNS (adjusted odds ratio 0.86; 95% confidence interval 0.48-1.55).

CONCLUSION

The pathogenic spectrum of BSI-causing bacteria in patients with HMs gradually shifted from Gram-positive to Gram-negative, especially from CoNS to K. pneumoniae. Considering that K. pneumoniae-BSI had a significantly higher 28-d mortality rate than CoNS-BSI, this evolving trend could adversely impact the clinical outcomes of patients with HMs.

Guidelines for Antibiotics Prescription in Critically Ill Patients

How to cite this article: Khilnani GC, Tiwari P, Mittal S, Kulkarni AP, Chaudhry D, Zirpe KG, et al. Guidelines for Antibiotics Prescription in Critically Ill Patients. Indian J Crit Care Med 2024;28(S2):S104-S216.

Essential Review of Oncological Emergencies

Innovations in oncology have expanded treatment eligibility, leading to a rise in cancer patients requiring critical care. This necessitates that all critical care clinicians possess a fundamental knowledge of prevalent oncological conditions and identify emergent scenarios requiring immediate action. This article will explore key oncological complications and their management approaches.

Analysis of bacteremia at first-line antibiotic treatment for febrile neutropenia in children and adolescents: A retrospective, single-center analysis

BACKGROUND

Control of bacterial and fungal infections is critical to improving outcomes in hematological neoplastic diseases of children and adolescents. In this study, a retrospective analysis of our previous studies on febrile neutropenia was performed to investigate bacteremia.

PROCEDURE

From August 2008 to December 2023, five antibiotic studies were performed for febrile and neutropenic pediatric patients who had been treated with chemotherapy, immunosuppressive therapy, or had received stem cell transplantation in the pediatric unit at Sapporo Hokuyu Hospital. The rate of positive blood culture, detected bacteria, and susceptibility of several types of antibiotics in febrile episodes were investigated.

RESULTS

Blood culture was positive in 133 of 1604 febrile episodes of 329 patients. Detected bacteria were Gram-positive cocci (61.2 %), Gram-negative bacilli (27.6 %), Gram-negative cocci (0.7 %), and Gram-positive bacilli (10.4 %). The incidence of bacteremia over time showed a decreasing trend with each passing year. In particular, the incidence of bacteremia was around 10 % in 2008-2013, whereas it was often below 5 % after 2020; this decrease was statistically significant. Although almost all detected bacteria and their susceptibilities to antibiotics (piperacillin/tazobactam, meropenem, ceftazidime, and cefozopran) did not change over time, all Escherichia coli detected after 2014 were extended-spectrum β-lactamase-producing bacteria.

Pathogenic spectrum and drug resistance of bloodstream infection in patients with acute myeloid leukaemia: a single centre retrospective study

Background

Bloodstream infection (BSI) represent a prevalent complication in haematological malignancies (HMs). Typically, Patients with BSI usually undergo empirical treatment pending pathogen identification. The timely and effective management of BSIs significantly influences patient prognosis. However, pathogen distribution in BSIs exhibits regional variation. In this study, we investigated the clinical characteristics, pathogen spectrum, drug resistance, risk factors of short-term prognosis and long-term prognostic factors of acute myeloid leukemia (AML) patients with BSI at Zhejiang Provincal People's Hospital.

Methods

From 2019 to 2021, a total of 56 AML patients with BSI were treated in the Department of Haematology at Zhejiang Province People's Hospital. Data regarding pathogen spectrum and drug resistance were collected for analysis. The patients were stratified into non-survivor cohort and survivor cohort within 30 days after BSI, and the predictors of 30-days mortality were identified through both univariate and multivariate Logistic regression analyses. Furthermore, Kaplan-Meier survival analysis and Cox regression analysis were employed to ascertain the risk factors associated with poor prognosis in AML patients complicated by BSI.

Results

A total of 70 strains of pathogenic bacteria were isolated from 56 AML patients with BSI. Gram-negative bacteria constituted the predominant pathogens (71.4%), with Klebsiella pneumoniae being the most prevalent (22.9%). Gram-positive bacteria and fungi accounted for 22.9% and 5.7%, respectively. Univariate and multivariate analyses revealed significant differences in total protein, albumin levels, and the presence of septic shock between the non-survivor cohort and the survior cohort 30 days post-BSI. COX regression analysis showed that agranulocytosis duration exceeding 20 days (HR:3.854; 95% CI: 1.451-10.242) and septic shock (HR:3.788; 95% CI: 1.729-8.299) were independent risk factors for poor prognosis in AML patients complicated by BSI. Notably, the mortality rate within 30 days after Stenotrophomonas maltophilia infection was up to 71.4%.

Conclusions

In this study, Gram-negative bacteria, predominantly Klebsiella pneumoniae, constituted the primary pathogens among AML patients with BSIs. Serum albumin levels and the presence of septic shock emerged as independent risk factors for mortality within 30 days among AML patients with BSI. In terms of long-term prognosis, extended agranulocytosis duration exceeding 20 days and septic shock were associated with elevated mortality rates in AML patients with BSI. Additionally, in our centre, Stenotrophomonas maltophilia infection was found to be associated with a poor prognosis. Early intervention for Stenotrophomonas maltophilia infection in our centre could potentially improve patient outcomes.

High mortality associated with inappropriate initial antibiotic therapy in hematological malignancies with Klebsiella pneumoniae bloodstream infections

Bloodstream infections caused by multidrug-resistant organisms such as Klebsiella pneumoniae are a significant challenge in managing hematological malignancies. This study aims to characterize the epidemiology of Klebsiella pneumoniae bloodstream infections specifically in patients with hematological malignancies, delineate the patterns of initial antibiotic therapy, assess the prevalence of resistant strains, identify risk factors for these resistant strains, and evaluate factors influencing patient outcomes. A retrospective analysis was conducted at a single center from January 2017 to December 2020, focusing on 182 patients with hematological malignancies who developed Klebsiella pneumoniae bloodstream infections. We compared the 30-day mortality rates between patients receiving appropriate and inappropriate antibiotic treatments, including the effectiveness of both single-drug and combination therapies. Kaplan-Meier survival analysis and multivariate logistic and Cox regression were used to identify factors influencing mortality risk. The 30-day all-cause mortality rate was 30.2% for all patients. The 30-day all-cause mortality rates were 77.2% and 8.8% in patients who received inappropriate initial treatment and appropriate initial treatment (p < 0.001). Inappropriate initial treatment significantly influenced mortality and was a key predictor of 30-day mortality, along with septic shock and previous intensive care unit (ICU) stays. Patients with carbapenem-resistant Klebsiella pneumoniae (CRKP) bloodstream infections exhibited more severe clinical symptoms compared to the CSKP group. The study demonstrates a significant association between empirical carbapenem administration and the escalating prevalence of CRKP and multidrug-resistant K. pneumoniae (MDR-KP) infections. Furthermore, the study identified inappropriate initial antibiotic therapy, septic shock, and ICU admission as independent risk factors for 30-day mortality.

Improving management of febrile neutropenia in oncology patients: the role of artificial intelligence and machine learning

INTRODUCTION

Artificial intelligence (AI) and machine learning (ML) have the potential to revolutionize the management of febrile neutropenia (FN) and drive progress toward personalized medicine.

AREAS COVERED

In this review, we detail how the collection of a large number of high-quality data can be used to conduct precise mathematical studies with ML and AI. We explain the foundations of these techniques, covering the fundamentals of supervised and unsupervised learning, as well as the most important challenges, e.g. data quality, 'black box' model interpretation and overfitting. To conclude, we provide detailed examples of how AI and ML have been used to enhance predictions of chemotherapy-induced FN, detection of bloodstream infections (BSIs) and multidrug-resistant (MDR) bacteria, and anticipation of severe complications and mortality.

EXPERT OPINION

There is promising potential of implementing accurate AI and ML models whilst managing FN. However, their integration as viable clinical tools poses challenges, including technical and implementation barriers. Improving global accessibility, fostering interdisciplinary collaboration, and addressing ethical and security considerations are essential. By overcoming these challenges, we could transform personalized care for patients with FN.

An Emergent Change in Epidemiologic and Microbiological Characteristics of Bloodstream Infections in Adults With Febrile Neutropenia Resulting From Chemotherapy for Acute Leukemia and Lymphoma at Reference Centers in Chile, Ecuador, and Peru

Background

Febrile neutropenia is a life-threatening condition commonly observed in patients with hematologic malignancies. The aim of this article is to provide updated knowledge about bloodstream infections in febrile neutropenia episodes within the Andean region of Latin America.

Method

This retrospective study was based in 6 hospitals in Chile, Ecuador, and Peru and included adult patients with acute leukemia or lymphoma and febrile neutropenia between January 2019 and December 2020.

Results

Of the 416 febrile neutropenia episodes, 38.7% had a bloodstream infection, 86% of which were caused by gram-negative rods, with Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa being the most frequently identified bacteria. K pneumoniae isolates were more frequently resistant than E coli to cefotaxime (65% vs 39.6%), piperacillin-tazobactam (56.7% vs 27.1%), and imipenem (35% vs 2.1%) and were more frequently multidrug resistant (61.7% vs 12.5%). Among P aeruginosa, 26.7% were resistant to ceftazidime, piperacillin-tazobactam, and imipenem, and 23.3% were multidrug resistant. Overall 30-day mortality was 19.8%, being higher with vs without a bloodstream infection (26.7% vs 15.3%, P = .005). Fever duration was also significantly longer, as well as periods of neutropenia and length of hospital stay for patients with bloodstream infection. Additionally, the 30-day mortality rate was higher for episodes with inappropriate vs appropriate empirical antibiotic therapy (41.2% vs 26.6%, P = .139).

Conclusions

Considering the high rates of bacteria-resistant infection and 30-day mortality, it is imperative to establish strategies that reduce the frequency of bloodstream infections, increasing early identification of patients at higher risks of multidrug bacteria resistance, and updating existing empirical antibiotic recommendations.

Oral minocycline as systemic therapy for uncomplicated venous access device-related bloodstream infection with coagulase-negative staphylococci after allogeneic hematopoietic cell transplantation

BACKGROUND

Venous access device-related bloodstream infection (VAD-BSI) with coagulase-negative staphylococci (CoNS) is a common complication after allogeneic hematopoietic cell transplantation (alloHCT). Standard systemic antimicrobial therapy for uncomplicated VAD-BSI with methicillin-resistant CoNS consists of intravenous (IV) vancomycin (vanco). This requires hospitalization, needs new competent venous access, exposes patients to potential toxicity (mainly renal) and increases the risk of commensal flora dysbiosis with selection of vanco-resistant enterococci. Combined with VAD management (removal or antibiotic locks), oral minocycline (mino) has been evaluated as an alternative systemic therapy for the treatment of uncomplicated VAD-BSIs with CoNS at our center, primarily when the reference treatment with IV vanco was not possible (renal failure or allergy) or when hospitalization was refused by patients. Here, we retrospectively report our single center experience with this mino-based approach.

PATIENTS AND METHODS

From January 2012 to December 2020, 24 uncomplicated VAD-BSIs with CoNS in 23 alloHCT patients were treated with oral mino as systemic antibiotic therapy in combination with VAD management. VAD were implantable ports (n = 17), tunneled catheter (n = 1) or PIC-lines (n = 6). Staphylococci were S. epidermidis (n = 21) or S. haemolyticus (n = 3). Mino was administered with a loading dose of 200 mg followed by 100 mg BID for 7-14 days. For 8 VAD-BSIs, patients were initially treated with IV vanco for the first 1-3 days followed by oral mino, while 16 VAD-BSIs were treated with oral mino as the sole antimicrobial agent for systemic therapy. VAD management consisted of catheter removal (for tunneled catheters and PIC-lines, n = 7) or antibiotic locks with vanco (n = 15) or gentamicin (n = 2) administered at least 3 times a week for 14 days (for ports).

RESULTS

Overall, clearance of bacteremia (as assessed by negativity for the same CoNS of surveillance peripheral blood cultures drawn between day+ 3 and +30 after initiation of systemic therapy) was achieved in all but 1 patient (with port) who had persistent bacteremia at day +9. No complication such as suppurative thrombophlebitis, endocarditis, distant foci of infection or BSI-related death was observed in any patient during the 3-month period after initiation of treatment. Regarding the 17 port-BSI cases for which VAD conservative strategy was attempted, failure of 3-month VAD preservation was documented in 7/17 cases and 3-month recurrence of VAD-BSI was observed in 3/17 cases (with 1 patient with cellulitis). Treatment with mino was well tolerated except for a mild skin rash in one patient.

CONCLUSION

Further prospective studies are needed to evaluate efficacy and safety of this approach.

Clinical Analysis of Bacterial Infection Characteristics in Lymphoma Patients with High-dose Chemotherapy Combined with Autologous Hematopoietic Stem Cell Transplantation-A Single-Centered Retrospective Study

BACKGROUND

High-dose chemotherapy combined with autologous hematopoietic stem cell transplantation (HDT/AHSCT) is used to treat lymphoma. Although AHSCT has made considerable strides and become safer, HDT-AHSCT infection continues to be a leading cause of morbidity and mortality associated with transplantation.

OBJECTIVE

To characterise pathogenic bacterial infections in HDT/AHSCT-treated lymphoma patients. The prevalence of pathogenic microorganisms and the timing of foci after transplantation, along with bloodstream infection (BSI) risk factors, can help determine the need for empirical antibiotics after AHSCT.

METHODS

We retrospectively analyzed 133 lymphoma patients treated by HDT/AHSCT from April 2017 to October 2021 at Peking University International Hospital, Beijing, China. We analyzed their clinical characteristics, microbiological distribution characteristics, and BSI risk factors in detail.

RESULTS

In order, intestinal infection (56 cases), BSI (17 cases), pulmonary (12 cases), upper respiratory tract (5 cases), and perianal (4 cases) were the most common locations of infection after HDT/AHSCT. The infection sites yielded 92 putative pathogenic pathogens, with bacteria predominating (61.96%), fungi (28.26%), viruses (5.43%), and mycoplasma (4.35%). Gram-negative bacteria (GNB) strains outnumbered gram-positive bacteria (GPB) strains (73.68%). Two strains of Escherichia coli produced extended-spectrum β-lactamase (ESBL) and one strain of carbapenem-resistant enterobacteriaceae (CRE). Methicillin-resistant Staphylococcus epidermidis (MRSE) had one strain. BSI was caused by Escherichia coli (82.35%), Intestinal mucositis (23.52%), and catheter-associated infections (11.76%). Age, CD34, pretreatment regimen, antibiotic regimen, and past chemotherapeutic agent lung damage were BSI risk variables in univariate analysis. CD34 and past chemotherapeutic drug lung damage were the primary causes of BSI after HDT/AHSCT for lymphoma.

CONCLUSION

High-dose chemotherapy combined with autologous hematopoietic stem cell transplantation (HDT/AHSCT) is used to treat lymphoma. Although AHSCT has made considerable strides and become safer, HDT-AHSCT infection continues to be a leading cause of morbidity and mortality associated with transplantation.

Dissecting bloodstream infections in febrile neutropenic patients with hematological malignancies, a decade-long single center retrospective observational study (2009-2019)

BACKGROUND

The use of ill-suited antibiotics is a significant risk factor behind the increase in the mortality, morbidity, and economic burden for patients who are under treatment for hematological malignancy (HM) and bloodstream infections (BSI). Such unfitting treatment choices intensify the evolution of resistant variants which is a public health concern due to possible healthcare-associated infection spread to the general population. Hence, this study aims to evaluate antibiograms of patients with BSI and risk factors associated with septicemia.

METHODS

A total of 1166 febrile neutropenia episodes (FNE) among 513 patients with HM from the National Center for Cancer Care and Research (NCCCR), Qatar, during 2009-2019 were used for this study. The socio-demographic, clinical, microbial, and anti-microbial data retrieved from the patient's health records were used.

RESULTS

We analyzed the sensitivity of gram-negative and gram-positive bacilli reported in HM-FN-BSI patients. Out of the total 512 microorganisms isolated, 416 (81%) were gram-negative bacteria (GNB), 76 (15%) were gram-positive bacteria (GPB) and 20 (4%) were fungi. Furthermore, in 416 GNB, 298 (71.6%) were Enterobacteriaceae sp. among which 121 (41%) were ESBL (Extended Spectrum Beta-Lactamase) resistant to Cephalosporine third generation and Piperacillin-Tazobactam, 54 (18%) were Carbapenem-resistant or multidrug-resistant organism (MDRO). It's noteworthy that the predominant infectious agents in our hospital include E. coli, Klebsiella species, and P. aeruginosa. Throughout the study period, the mortality rate due to BSI was 23%. Risk factors that show a significant correlation with death are age, disease status, mono or polymicrobial BSI and septic shock.

CONCLUSION

Decision pertaining to the usage of antimicrobials for HM-FN-BSI patients is a critical task that relies on the latest pattern of prevalence, treatment resistance, and clinical outcomes. Analysis of the antibiogram of HM-FN-BSI patients in Qatar calls for a reconsideration of currently followed empirical antibiotic therapy towards better infection control and antimicrobial stewardship.

Chlorhexidine gluconate-coated gel pad dressings for prevention of central venous catheter-related bloodstream infections in patients with hematologic diseases or autologous stem cell transplantation: A registry-based matched-pair analysis

OBJECTIVES

Chlorhexidine gluconate (CHG)-coated gel pad dressings for central venous catheter (CVC) may prevent CVC-related bloodstream infections (CRBSI). However, real-world data showing beneficial effects in patients with hematologic malignancies are scarce.

METHODS

In a matched-pair analysis with data from a multicenter CVC registry, non-tunneled jugular and subclavian vein CVC in adults with hematologic malignancies or germ cell tumors (including patients receiving autologous hematopoietic stem cell transplantation [ASCT]) with CHG were compared with non-CHG dressings. The primary endpoint was definite CRBSI rate within 14 days (dCRBSI14) of CVC insertion; secondary endpoints were combined rate of definite or probable CRBSI within 14 days (dpCRBSI14), overall (dpCRBSI), and CRBSI incidences of all estimates.

RESULTS

In total, 2070 CVCs were assessed. There was no statistically significant difference in dCRBSI14 (2.3% vs. 3.5%) between patients with and without CHG gel dressings. Likewise, with regards to dpCRBSI14 (6.2% vs. 6.3%) and the overall dpCRBSI rate (9.2% vs. 10.5%), no significant difference was detected. Furthermore, dCRBSI14 incidence (2.0 vs. 3.2/1000 CVC days), dpCRBSI14 incidence (5.4 vs. 5.6/1000 CVC days), and overall CRBSI incidence (5.5 vs. 6.0/1000 CVC days) showed no significant differences.

CONCLUSIONS

CRBSI rates were not reduced by the use of CHG gel dressings in patients with hematologic malignancies and/or ASCT.

Low utilization of vancomycin in febrile neutropenia: real-world evidence from 4 Brazilian centers

PURPOSE

The prompt initiation of a betalactam antibiotic in febrile neutropenic patients is considered standard of care, while the empiric use of vancomycin is recommended by guidelines in specific situations, with a low level of evidence. The objective of this study was to assess the utilization of vancomycin in the management of febrile neutropenia within four Brazilian medical centers that implemented more stringent criteria for its administration.

METHODS

A comprehensive retrospective analysis was performed encompassing all instances of febrile neutropenia observed during the period from 2013 to 2019. The primary focus was to identify the reasons for initiating vancomycin therapy.

RESULTS

A total of 536 consecutive episodes of febrile neutropenia were documented, involving 384 patients with a median age of 52 years (range 18-86). Chemotherapy preceded febrile neutropenia in 59.7% of cases, while 40.3% occurred after hematopoietic stem cell transplantation. The most prevalent underlying diseases were acute myeloid leukemia (26.5%) and non-Hodgkin's lymphoma (22%). According to international guidelines, vancomycin should have been initiated at the onset of fever in 145 episodes (27%); however, it was administered in only 27 cases (5.0%). Three episodes were associated with Staphylococcus aureus bacteremia, two of which were methicillin resistant. The 15-day and 30-day mortality rates were 5.0% and 9.9%, respectively.

CONCLUSIONS

The results of this study underscore the notably low utilization rate of vancomycin in cases of febrile neutropenia, despite clear indications outlined in established guidelines. These findings emphasize the importance of carefully implementing guideline recommendations, considering local epidemiological factors, especially when the strength of recommendation is weak.

Clinical characteristics and prognostic risk factors of candidemia in non-neutropenic patients: a retrospective cohort study

This study aimed to determine the clinical characteristics and the prognostic risk factors in non-neutropenic patients with candidemia. Data were retrospectively collected through the medical record information system. Non-neutropenic patients with candidemia were relatively aged, with a more than one-third rate of in-hospitalization mortality. In multivariate analysis, APACHE II score (adjusted odds ratio [aOR], 1.138; 95% confidence interval [CI], 1.067-1.213), septic shock (aOR, 5.704; 95% CI, 2.639-12.326) and RRT (aOR, 16.152; 95% CI, 2.628-99.275) (all P < 0.01) were independent related with non-survivors. In conclusion, non-neutropenic patients with candidemia have a high in-hospitalization mortality, and APACHE II, septic shock, and RRT are independently factors.

Impact of Antimicrobial Drug-Drug Interactions on Acute Kidney Injury after Allogeneic Hematopoietic Cell Transplantation

Acute kidney injury (AKI) is one of the major complications after allogeneic hematopoietic stem cell transplantation (allo-HSCT). The use of multiple antimicrobials is one of the major causes of post-transplantation AKI, owing to the potential nephrotoxicity of each agent and of drug-drug interactions (DDIs). No satisfactory reports on DDIs the field of allo-HSCT have been published. We performed a retrospective analysis to compare the incidence of AKI within 100 days post-transplantation. A total of 465 allo-HSCTs in 416 patients were analyzed, and the cumulative incidence of AKI was 40.0%. AKI was associated with significantly reduced overall survival (hazard ratio [HR], 2.66; 95% confidence interval [CI] 1.95 to 3.55; P < .01) and increased transplantation-related mortality (HR, 4.77, 95% CI, 2.90 to 7.88; P < .01). A higher incidence of AKI was significantly associated with the use of ciprofloxacin, cefepime, tazobactam/piperacillin, meropenem, vancomycin, liposomal amphotericin B, ganciclovir, and foscarnet. Among these drugs, combinations of vancomycin plus tazobactam/piperacillin (HR, 2.23; P = .09 for interaction), ganciclovir plus cefepime (HR, 5.93; P = .04), and ganciclovir plus meropenem (HR, 2.63; P = .12) synergistically increased the risk of AKI, whereas combinations involving teicoplanin did not. This is the first report dealing with DDIs after allo-HSCT, indicating that such combinations should be avoided to preserve renal function and reduce AKI-related morbidity and mortality.

High Rate of Inappropriate Antibiotics in Patients with Hematologic Malignancies and Pseudomonas aeruginosa Bacteremia following International Guideline Recommendations

Optimal coverage of Pseudomonas aeruginosa is challenging in febrile neutropenic patients due to a progressive increase in antibiotic resistance worldwide. We aimed to detail current rates of resistance to antibiotics recommended by international guidelines for P. aeruginosa isolated from bloodstream infections (BSI) in patients with hematologic malignancies. Secondarily, we aimed to describe how many patients received inappropriate empirical antibiotic treatment (IEAT) and its impact on mortality. We conducted a retrospective, multicenter cohort study of the last 20 BSI episodes caused by P. aeruginosa in patients with hematologic malignancies from across 14 university hospitals in Spain. Of the 280 patients with hematologic malignancies and BSI caused by P. aeruginosa, 101 (36%) had strains resistant to at least one of the β-lactam antibiotics recommended in international guidelines, namely, cefepime, piperacillin-tazobactam, and meropenem. Additionally, 21.1% and 11.4% of the strains met criteria for MDR and XDR P. aeruginosa, respectively. Even if international guidelines were followed in most cases, 47 (16.8%) patients received IEAT and 66 (23.6%) received inappropriate β-lactam empirical antibiotic treatment. Thirty-day mortality was 27.1%. In the multivariate analysis, pulmonary source (OR 2.22, 95% CI 1.14 to 4.34) and IEAT (OR 2.67, 95% CI 1.37 to 5.23) were factors independently associated with increased mortality. We concluded that P. aeruginosa-causing BSI in patients with hematologic malignancies is commonly resistant to antibiotics recommended in international guidelines, which is associated with frequent IEAT and higher mortality. New therapeutic strategies are needed. IMPORTANCE Bloodstream infection (BSI) caused by P. aeruginosa is related with an elevated morbidity and mortality in neutropenic patients. For this reason, optimal antipseudomonal coverage has been the basis of all historical recommendations in the empirical treatment of febrile neutropenia. However, in recent years the emergence of multiple types of antibiotic resistances has posed a challenge in treating infections caused by this microorganism. In our study we postulated that P. aeruginosa-causing BSI in patients with hematologic malignancies is commonly resistant to antibiotics recommended in international guidelines. This observation is associated with frequent IEAT and increased mortality. Consequently, there is a need for a new therapeutic strategy.

Acute Oncologic Complications: Clinical-Therapeutic Management in Critical Care and Emergency Departments

Introduction. It is now known that cancer is a major public health problem; on the other hand, it is less known, or rather, often underestimated, that a significant percentage of cancer patients will experience a cancer-related emergency. These conditions, depending on the severity, may require treatment in intensive care or in the emergency departments. In addition, it is not uncommon for a tumor pathology to manifest itself directly, in the first instance, with a related emergency. The emergency unit proves to be a fundamental and central unit in the management of cancer patients. Many cancer cases are diagnosed in the first instance as a result of symptoms that lead the patient's admittance into the emergency room. Materials and Methods. This narrative review aims to analyze the impact of acute oncological cases in the emergency setting and the role of the emergency physician in their management. A search was conducted over the period January 1981-April 2023 using the main scientific platforms, including PubMed, Scopus, Medline, Embase and Google scholar, and 156 papers were analyzed. Results. To probe into the main oncological emergencies and their management in increasingly overcrowded emergency departments, we analyzed the following acute pathologies: neurological emergencies, metabolic and endocrinological emergencies, vascular emergencies, malignant effusions, neutropenic fever and anemia. Discussion/Conclusions. Our analysis found that a redefinition of the emergency department connected with the treatment of oncology patients is necessary, considering not only the treatment of the oncological disease in the strict sense, but also the comorbidities, the oncological emergencies and the palliative care setting. The need to redesign an emergency department that is able to manage acute oncological cases and end of life appears clear, especially when this turns out to be related to severe effects that cannot be managed at home with integrated home care. In conclusion, a redefinition of the paradigm appears mandatory, such as the integration between the various specialists belonging to oncological medicine and the emergency department. Therefore, our work aims to provide what can be a handbook to detect, diagnose and treat oncological emergencies, hoping for patient management in a multidisciplinary perspective, which could also lead to the regular presence of an oncologist in the emergency room.

Microbiological Spectrum of Neutropenic Sepsis in Cancer Patients Admitted to a Tertiary Health Care Centre

OBJECTIVE

To examine the microbiological profile, sensitivity of organisms, treatment and outcomes of in-patients suffering from febrile neutropenia in a tertiary healthcare centre.

METHODS

Data was obtained from the Electronic Medical Health records in Aster Medcity, Cochin, IND. The study population included adult patients undergoing treatment for hematologic malignancies or solid tumors in the hospital between January 2021 and March 2023. Febrile neutropenia episodes were identified based on (1) absolute neutrophil count ≤1500 mm3, (2) at least a single recorded oral temperature of >38.0∘C (100.4∘F) sustained over a one-hour period. Febrile neutropenia consequences included ICU admission, length of ICU admission, and mortality.

RESULTS

Total 115 cases of febrile neutropenia were identified in the time period from January 2021 to March 2023. Organisms were isolated from 43% of all the cultures taken. The most common organism isolated was Klebsiella pneumoniae (32.81%), followed by Escherichia coli (29.69%) and Pseudomonas aeruginosa (10.94%). Other organisms that were also isolated were Candida albicans (3.13%), Aeromonas hydrophilia, Acinetobacter baumannii, Burkholderia cepacia, Enterobacter cloacae, Enterococcus faecium, Staphylococcus epidermidis, Staphylococcus hemolyticus, Streptococcus spp, and one case of Ralstonia mannitolytica. Multi-drug resistance (MDR) was seen in 33% of isolates and extensive-drug resistance was seen in 19% of isolates. E. coli showed the highest prevalence of antibiotic resistance with 68% growing MDR isolates and 16% growing XDR isolates. ICU stay was required in 34% of patients with a median duration of stay of three days. A mortality rate of 16.52% was seen, with 17.11% in hematological malignancies and 15.38% in solid tumors.

CONCLUSIONS

This study showed an increasing prevalence of Gram-negative bacterial infection in patients with febrile neutropenia. It also shows a high prevalence of antibiotic resistance in microbes in febrile neutropenia. Larger multi-hospital studies are required to better understand the microbiological profile of febrile neutropenia and identify the developing antimicrobial resistance trends.

A Comprehensive Review of Identification Methods for Pathogenic Yeasts: Challenges and Approaches

Given the increasing incidence of yeast infections and the presence of drug-resistant isolates, accurate identification of the pathogenic yeasts is essential for the management of yeast infections. In this review, we tried to introduce the routine and novel techniques applied for yeast identification. Laboratory identification methods of pathogenic yeast are classified into three categories; I. conventional methods, including microscopical and culture-base methods II. biochemical/physiological-processes methods III. molecular methods. While conventional and biochemical methods require more precautions and are not specific in some cases, molecular diagnostic methods are the optimum tools for diagnosing pathogenic yeasts in a short time with high accuracy and specificity, and having various methods that cover different purposes, and affordable costs for researchers. Nucleotide sequencing is a reference or gold standard for identifying pathogenic yeasts. Since it is an expensive method, it is not widely used in developing countries. However, novel identification techniques are constantly updated, and we recommend further studies in this field. The results of this study will guide researchers in finding more accurate diagnostic method(s) for their studies in a short period of time.

An Overview of Selected Bacterial Infections in Cancer, Their Virulence Factors, and Some Aspects of Infection Management

In cancer development and its clinical course, bacteria can be involved in etiology and secondary infection. Regarding etiology, various epidemiological studies have revealed that Helicobacter pylori can directly impact gastric carcinogenesis. The Helicobacter pylori-associated virulence factor cytotoxin-associated gene A perhaps plays an important role through different mechanisms such as aberrant DNA methylation, activation of nuclear factor kappa B, and modulation of the Wnt/β-catenin signaling pathway. Many other bacteria, including Salmonella and Pseudomonas, can also affect Wnt/β-catenin signaling. Although Helicobacter pylori is involved in both gastric adenocarcinoma and mucosa-associated lymphoid tissue lymphoma, its role in the latter disease is more complicated. Among other bacterial species, Chlamydia is linked with a diverse range of diseases including cancers of different sites. The cellular organizations of Chlamydia are highly complex. Interestingly, Escherichia coli is believed to be associated with colon cancer development. Microorganisms such as Escherichia coli and Pseudomonas aeruginosa are frequently isolated from secondary infections in cancer patients. In these patients, the common sites of infection are the respiratory, gastrointestinal, and urinary tracts. There is an alarming rise in infections with multidrug-resistant bacteria and the scarcity of suitable antimicrobial agents adversely influences prognosis. Therefore, effective implementation of antimicrobial stewardship strategies is important in cancer patients.

Anti-Pseudomonas aeruginosa Vaccines and Therapies: An Assessment of Clinical Trials

Pseudomonas aeruginosa is a Gram-negative opportunistic pathogen that causes high morbidity and mortality in cystic fibrosis (CF) and immunocompromised patients, including patients with ventilator-associated pneumonia (VAP), severely burned patients, and patients with surgical wounds. Due to the intrinsic and extrinsic antibiotic resistance mechanisms, the ability to produce several cell-associated and extracellular virulence factors, and the capacity to adapt to several environmental conditions, eradicating P. aeruginosa within infected patients is difficult. Pseudomonas aeruginosa is one of the six multi-drug-resistant pathogens (ESKAPE) considered by the World Health Organization (WHO) as an entire group for which the development of novel antibiotics is urgently needed. In the United States (US) and within the last several years, P. aeruginosa caused 27% of deaths and approximately USD 767 million annually in health-care costs. Several P. aeruginosa therapies, including new antimicrobial agents, derivatives of existing antibiotics, novel antimicrobial agents such as bacteriophages and their chelators, potential vaccines targeting specific virulence factors, and immunotherapies have been developed. Within the last 2-3 decades, the efficacy of these different treatments was tested in clinical and preclinical trials. Despite these trials, no P. aeruginosa treatment is currently approved or available. In this review, we examined several of these clinicals, specifically those designed to combat P. aeruginosa infections in CF patients, patients with P. aeruginosa VAP, and P. aeruginosa-infected burn patients.

Agranulocytosis Secondary to Cancer Chemotherapy Associated With Higher In-Hospital Mortality in Patients With Central Line Insertion During a Hospital Stay

Background Agranulocytosis secondary to cancer chemotherapy (ASCC) remains a leading cause of morbidity and mortality. Central line-associated bloodstream infections (CLABSI) are also particularly prevalent in these populations and may portend a poorer outcome. Our study serves to investigate the relationship between patients with agranulocytosis secondary to cancer chemotherapy and the insertion of a central venous catheter (CVC) with respect to in-hospital mortality. Methods and results We utilized the National Inpatient Survey 2019 database. We utilized the International Classification of Diseases (ICD)-10 CM codes to identify ASCC and other medical comorbidities. We utilized ICD-10 PCS codes to identify CVC insertions. Multivariate logistic regression was utilized to study the effect of CVC insertion on in-hospital mortality. In patients with ASCC, CVC insertion was associated with a higher in-hospital mortality (unadjusted: 11.9% vs. 1%, p<0.001, adjusted OR 19.27, 95% CI 5.84 - 65.6, p<0.001) adjusted for baseline characteristics and other comorbidities. Patients in the study cohort who were older than 70 years of age also had a higher in-hospital mortality relative to younger age groups (adjusted OR 2.31, 95% CI 1.04-5.13, p<0.039). Conclusion In patients with ASCC, CVC insertion during hospitalization is associated with higher in-hospital mortality.

Molecular and Clinical Data of Antimicrobial Resistance in Microorganisms Producing Bacteremia in a Multicentric Cohort of Patients with Cancer in a Latin American Country

Patients with cancer have a higher risk of severe bacterial infections. This study aims to determine the frequency, susceptibility profiles, and resistance genes of bacterial species involved in bacteremia, as well as risk factors associated with mortality in cancer patients in Colombia. In this prospective multicenter cohort study of adult patients with cancer and bacteremia, susceptibility testing was performed and selected resistance genes were identified. A multivariate regression analysis was carried out for the identification of risk factors for mortality. In 195 patients, 206 microorganisms were isolated. Gram-negative bacteria were more frequently found, in 142 cases (68.9%): 67 Escherichia coli (32.5%), 36 Klebsiella pneumoniae (17.4%), and 21 Pseudomonas aeruginosa (10.1%), and 18 other Gram-negative isolates (8.7%). Staphylococcus aureus represented 12.4% (n = 25). Among the isolates, resistance to at least one antibiotic was identified in 63% of them. Genes coding for extended-spectrum beta-lactamases and carbapenemases, blaCTX-M and blaKPC, respectively, were commonly found. Mortality rate was 25.6% and it was lower in those with adequate empirical antibiotic treatment (22.0% vs. 45.2%, OR: 0.26, 95% CI: 0.1-0.63, in the multivariate model). In Colombia, in patients with cancer and bacteremia, bacteria have a high resistance profile to beta-lactams, with a high incidence of extended-spectrum beta-lactamases and carbapenemases. Adequate empirical treatment diminishes mortality, and empirical selection of treatment in this environment of high resistance is of key importance.

Impact of Fluoroquinolone Prophylaxis on Neutropenic Fever, Infections, and Antimicrobial Resistance in Newly Diagnosed AML Patients

INTRODUCTION

Fluoroquinolone prophylaxis is recommended during induction chemotherapy for patients with acute myeloid leukemia (AML) to reduce risk of neutropenic fever and systemic bacterial infections. We evaluated the effectiveness of primary fluoroquinolone prophylaxis in an area with high fluoroquinolone resistance.

MATERIALS AND METHODS

We performed a retrospective chart review of newly diagnosed adult AML patients who received frontline therapy at Mount Sinai Hospital in New York, NY, between 2012 and 2019. Primary outcome was development of neutropenic fever. Secondary outcomes were development of systemic bacterial infections and infections with multidrug-resistant organisms and Clostridioides difficile. Infectious outcomes were collected through 6 months after therapy initiation. We estimated the effect of fluoroquinolone prophylaxis with a time-dependent Cox proportional hazards model.

RESULTS

Of 121 included patients, 87 received antibiotic prophylaxis and 34 did not. There was no difference in baseline characteristics, although the prophylaxis group had longer neutropenia duration (median 30 vs. 23 days, P = .013). The prophylaxis group had a reduced risk of neutropenic fever (hazard ratio 0.59, P = .039). The prophylaxis group had fewer gram-positive (P = .043) and gram-negative (P = .049) bloodstream infections and fewer clinically documented infections during frontline therapy (P = .005) and follow-up (P = .026). There was no difference in incidence of C. difficile or infection with fluoroquinolone-resistant or multidrug-resistant organisms. There was no mortality difference between groups.

CONCLUSION

In an area with high fluoroquinolone resistance, primary fluoroquinolone prophylaxis in newly diagnosed AML patients reduced the risk of neutropenic fever and systemic bacterial infections without increased antimicrobial resistance. Prospective, randomized studies are needed to confirm these observations.

Pharmacokinetics of Vancomycin among Patients with Chemotherapy-Associated Febrile Neutropenia: Which Would Be the Best Dosing to Obtain Appropriate Exposure?

Previous research has determined that the required doses for treating febrile neutropenia with vancomycin are higher than the doses used conventionally. These recommendations have been made considering pharmacotherapeutic goals based on minimum concentration (Cmin) between 15–20 mg/L. This study was developed to evaluate dose recommendations based on the achievement of a target consisting of ratio of area under the curve over minimum inhibitory concentration (AUC24h/MIC) ≥400 in this population of individuals. This study was conducted in a referral hospital for cancer treatment, study participants received vancomycin doses of 1g every 12 h in 2-4-h infusions. Vancomycin was described by a two-compartment pharmacokinetic model with clearance dependent on the estimated glomerular filtration rate. Simulations were performed taking into account a reduced version of the model to establish the influence of controllable and non-controllable variables on the probability of achieving several PK-PD targets. A dose of 2.5g/day in patients with estimated glomerular filtration rate (eGFR) between 80 and 122mL/min/1.73m2 was adequate to achieve the pharmacotherapeutic target. A discrepancy was found between AUC-based and Cmin-based PK/PD indices, the former being affected by the dose and creatinine clearance while the latter highly influenced by the interval between doses.

Scheduled removal of central venous catheters (CVC) to prevent CVC-related bloodstream infections in patients with hematological disease or autologous stem cell transplantation: a registry-based randomized simulation-study

Although not generally recommended, scheduled central venous catheter (CVC) removal is sometimes carried out in order to reduce the CVC-related bloodstream infection (CRBSI) incidence. We conducted a simulation for scheduled CVC removal within the multicenter CRBSI registry (SECRECY). Non-tunneled jugular and subclavian CVC in patients with hematological disease or with germ cell tumors (including patients receiving autologous stem cell transplantation [SCT]) were included. Cases were randomized in a 1:1:1:1 ratio to either a simulated, scheduled CVC removal after 7, 14, and 21 days, or to non-simulated, unscheduled CVC removal (control group). The primary endpoint was definitive CRBSI incidence for a scheduled CVC removal after 14 days (dCRBSI-D14rmv). Among other, secondary endpoints were definite CRBSI incidence for a scheduled removal after 7 days (dCRBSI-D7rmv) and 21 days (dCRBSI-D21rmv). Data on 2984 CVC were included. Patients' median age was 59 (range 16-95) years, 58.8% being male. The vast majority (98.4%) were patients with hematological malignancies. Jugular veins were the main insertion site (93.2%). dCRBSI-D14rmv was 3.10/1000 CVC days as compared to 4.15/1000 CVC days in the control group (p = 0.23). There was a significant difference between dCRBSI-D7rmv (0.86/1000 CVC days) and controls (p < 0.001), but not between dCRBSI-D21rmv (4.10/1000 CVC days) and controls (p = 0.96). Our data suggest that in patients with hematological diseases or autologous SCT recipients scheduled CVC removal after 14 days does not result in a lower CRBSI incidence compared to unscheduled removal.Trial registration: DRKS00006551, 2014/09/29, retrospectively registered.

Evaluation of Possible Effects of the COVID-19 Pandemic on Febrile Neutropenia Episodes in Children With Acute Leukemia

With the rapid spread of coronavirus disease 2019 (COVID-19) around the globe, concerns about the management of patients with malignancy have risen significantly. This study aimed to investigate the possible impact of the COVID-19 pandemic and prevention policies on the incidence and etiology of febrile neutropenia (FN) episodes in children with acute leukemia. Children who had acute leukemia and were diagnosed as FN in a tertiary center from March 2018 to March 2021 were included in the study. FN episodes were grouped as prepandemic and postpandemic based on the date that pandemic was declared. Relevant data were collected retrospectively. We evaluated 113 FN episodes (75.2% were prepandemic) of 46 patients, a median of 4.7 (2.6 to 12.6) years of age. The number of FN episodes per patient did not differ between prepandemic and postpandemic periods ( P =0.476). There was no significant difference among the 2 groups regarding the microbiologic causes, focus of fever, and clinical outcomes in FN episodes. Two of the patients were diagnosed as COVID-19 and recovered without any complications. In conclusion, we showed that the incidence and etiology of FN episodes were similar before and during the COVID-19 pandemic in children with acute leukemia.

Clinical and Epidemiological Characteristics of Bloodstream Infections in Head and Neck Cancer Patients: A Decadal Observational Study

This retrospective study aims to describe the clinico-epidemiological characteristics of bloodstream infections (BSIs) and the risk factors in patients with head and neck cancer (n = 227) treated at the Department of Otolaryngology, Head and Neck Surgery, Tohoku University Hospital between April 2011 and March 2021. Overall, 23.3% of blood cultures were positive. In the culture-positive group, catheter-related bloodstream infections (CRBSIs) were the most common (38.8%), followed by respiratory tract infections (19.4%), and catheter-associated urinary tract infections (6.0%). Methicillin-resistant Staphylococcus aureus (26.9%), Staphylococcus epidermidis (17.9%), and Pseudomonas aeruginosa (10.4%) infections were common. The most frequent treatment for head and neck cancer was surgery (23.9%), followed by treatment interval or palliative care (19.4%), and single radiotherapy (13.4%). The 30-day mortality rate was significantly higher in the BSI than in the non-BSI group (10.4% vs. 1.8%, respectively). CRBSIs are the most frequent source of BSIs in patients with head and neck cancer. In conclusion, central venous catheters or port insertion should be used for a short period to prevent CRBSIs. The risk of developing BSI should be considered in patients with pneumonia. Understanding the epidemiology of BSIs is crucial for diagnosing, preventing, and controlling infections in patients with head and neck cancer.

Niclosamide-loaded nanoparticles disrupt Candida biofilms and protect mice from mucosal candidiasis

Candida albicans biofilms are a complex multilayer community of cells that are resistant to almost all classes of antifungal drugs. The bottommost layers of biofilms experience nutrient limitation where C. albicans cells are required to respire. We previously reported that a protein Ndu1 is essential for Candida mitochondrial respiration; loss of NDU1 causes inability of C. albicans to grow on alternative carbon sources and triggers early biofilm detachment. Here, we screened a repurposed library of FDA-approved small molecule inhibitors to identify those that prevent NDU1-associated functions. We identified an antihelminthic drug, Niclosamide (NCL), which not only prevented growth on acetate, C. albicans hyphenation and early biofilm growth, but also completely disengaged fully grown biofilms of drug-resistant C. albicans and Candida auris from their growth surface. To overcome the suboptimal solubility and permeability of NCL that is well known to affect its in vivo efficacy, we developed NCL-encapsulated Eudragit EPO (an FDA-approved polymer) nanoparticles (NCL-EPO-NPs) with high niclosamide loading, which also provided long-term stability. The developed NCL-EPO-NPs completely penetrated mature biofilms and attained anti-biofilm activity at low microgram concentrations. NCL-EPO-NPs induced ROS activity in C. albicans and drastically reduced oxygen consumption rate in the fungus, similar to that seen in an NDU1 mutant. NCL-EPO-NPs also significantly abrogated mucocutaneous candidiasis by fluconazole-resistant strains of C. albicans, in mice models of oropharyngeal and vulvovaginal candidiasis. To our knowledge, this is the first study that targets biofilm detachment as a target to get rid of drug-resistant Candida biofilms and uses NPs of an FDA-approved nontoxic drug to improve biofilm penetrability and microbial killing.

Adaptation of Bacteria to Antineoplastic Agents Involves Persister Cells and Increases Resistance to Antibiotics

The increasing number of life-threatening infections observed in cancer patients has been ascribed to chemotherapy-induced neutropenia and to invasive medical procedures such as surgery and the application of catheters. In this study, it was questioned if the infections could also be favored by an increased resistance of bacteria due to the adaptation to antineoplastic agents used in chemotherapy. After exposure to several antineoplastic agents, it was observed that cells of Staphylococcus aureus, Mycobacterium vaccae, Pseudomonas aeruginosa, and Escherichia coli changed the fatty acid profile of their cellular membranes, produced exopolymeric substances, and formed aggregates that adhered to surfaces. Additionally, when exposed to high concentrations of these compounds, a persister sub-population could be identified. After adaptation to antineoplastic agents, the minimum inhibitory concentration (MIC) of several antibiotics increased considerably in the tested strains.

Pathogen detection by metagenomic next generation sequencing during neutropenic fever in patients with hematological malignancies

Background

Febrile neutropenia (FN) following chemotherapy is a major cause of morbidity during cancer treatment. The performance of metagenomic next-generation sequencing (mNGS) of circulating cell-free DNA from plasma may be superior to blood culture (BC) diagnostics for identification of causative pathogens. The aim of this study was to validate mNGS (DISQVER test) for the detection of pathogens in hematologic patients with FN.

Methods

We collected paired whole blood specimens from central venous catheter and peripheral vein during FN for BC and mNGS testing. We repeated paired sampling at the earliest after 3 days of fever, which was defined as one FN episode. All clinical data were retrospectively reviewed by an infectious disease expert panel. We calculated percent positive agreement (PPA), percent negative agreement (PNA), percent overall agreement (POA), and sensitivity and specificity.

Results

We analyzed a total of 98 unselected FN episodes in 61 patients who developed predominantly FN after conditioning therapy for allogeneic (n = 22) or autologous (n = 21) hematopoietic stem cell transplantation. Success rate of mNGS was 99% (97/98). Positivity rate of mNGS was 43% (42/97) overall and 32% (31/97) excluding viruses compared to 14% (14/98) in BC. PPA, PNA and POA between mNGS and BC were 84.6% (95% CI, 54.6% to 98.1%), 63.1% (51.9% to 73.4%) and 66% (55.7% to 75.3%), respectively. Sensitivity for bacteria or fungi was 40% (28.0% to 52.9%) and 18.5% (9.9% to 30.0%), respectively.

Conclusion

Pathogen detection by mNGS (DISQVER) during unselected FN episodes shows twofold higher sensitivity and a broader pathogen spectrum than BC.

Metagenomic shotgun sequencing of blood to identify bacteria and viruses in leukemic febrile neutropenia

Despite diagnostic advances in microbiology, the etiology of neutropenic fever remains elusive in most cases. In this study, we evaluated the utility of a metagenomic shotgun sequencing based assay for detection of bacteria and viruses in blood samples of patients with febrile neutropenia. We prospectively enrolled 20 acute leukemia patients and obtained blood from these patients at three time points: 1) anytime from onset of neutropenia until before development of neutropenic fever, 2) within 24 hours of onset of neutropenic fever, 3) 5–7 days after onset of neutropenic fever. Blood samples underwent sample preparation, sequencing and analysis using the iDTECT® Dx Blood v1® platform (PathoQuest, Paris, France). Clinically relevant viruses or bacteria were detected in three cases each by metagenomic shotgun sequencing and blood cultures, albeit with no concordance between the two. Further optimization of sample preparation methods and sequencing platforms is needed before widespread adoption of this technology into clinical practice.

Bloodstream Infections in Hematologic Malignancy Patients with Fever and Neutropenia: Are Empirical Antibiotic Therapies in the United States Still Effective?

Background

Rising antimicrobial resistance rates may impact the efficacy of empirical antibiotic treatment for febrile neutropenia in high-risk cancer patients. Lacking contemporary data about the epidemiology, antibiotic resistance patterns, and clinical outcomes from bloodstream infections (BSI) in U.S. cancer patients, it is unclear if current guidelines remain relevant.

Methods

In a cross-sectional study, fourteen U.S. cancer centers prospectively identified BSIs in high-risk FN patients, including those receiving chemotherapy for hematologic malignancies or hematopoietic stem cell transplantation.

Results

Among 389 organsims causing BSI in 343 patients, there was an equal distribution of Gram-negative (GN) and Gram-positive (GP) bacteria, with variability across centers. Cefepime and piperacillin-tazobactam were the most commonly prescribed empirical antibiotics for FN, at 62% and 23% respectively; a GP-directed agent was empirically included in nearly half of all FN episodes within the first 24 hours. Susceptibility to fluoroquinolones, cefepime, piperacillin-tazobactam, and carbapenems was 49%, 84%, 88% and 96% respectively among GN isolates. Critical illness (CrI), defined as a new requirement for mechanical ventilation, vasopressor or death within 30 days, occurred in 15% and did not correlate with fluoroquinolone prophylaxis, organism type, initial antibiotics or adequacy of coverage. Only severity of illness at presentation, signified by a Pitt bacteremia score &gt; 2, predicted for critical illness within 30 days. Mortality was 4% by day 7 and 10% overall.

Conclusion

In accordance with U.S. guidelines, cefepime or piperacillin-tazobactam remain effective agents or empirical treatment for high risk cancer patients with FN who are stable at presentation, maintaining high GN pathogen susceptibility and yielding excellent outcomes.

Clinical Analysis of Bloodstream Infection of Escherichia coli in Patients with Pancreatic Cancer from 2011 to 2019

Background

Pancreatic cancer patients were particularly predisposed to develop Escherichia coli (E. coli) bloodstream infection (BSI); however, little information is currently available. We set out to find E. coli BSI's risk factors in pancreatic cancer to provide valuable experience.

Methods

We retrospectively analyzed the clinical data of pancreatic cancer patients (31 cases with E. coli BSI and 93 cases without BSI) by a case-control study. SPSS 17.0 was adopted to perform univariate and multivariate analyses. Bacterial resistance analysis was performed by Whonet 5.6.

Results

Hospitalization days ≥7 days, number of admissions ≥2 times, surgery, chemotherapy, the type of antibiotics used ≥2 species, albumin<40.0 g/L, and prealbumin < 0.2 g/L were the potential risk factors for pancreatic cancer patients with E. coli BSI (P < 0.1). Multivariate logistic regression showed hospitalization days ≥7 days (OR = 11.196, 95% CI = 0.024–0.333, P < 0.001), surgery (OR = 32.053, 95% CI = 0.007–0.137, P < 0.001), and chemotherapy (OR = 6.174, 95% CI = 0.038–0.688, P=0.014) were the independent risk factors for E. coli BSI of pancreatic cancer patients. E. coli resistant to carbapenems was rare; they were susceptible to cephamycin and piperacillin/tazobactam. The 90-day mortality rate of the infected group was significantly higher than the control group (41.9% versus 8.6%, P < 0.001).

Conclusions

Hospitalization days ≥7 days, surgery, and chemotherapy are the independent risk factors for E. coli BSI of pancreatic cancer patients, which allows us to identify patients at potential risk and perform preventive treatment in time.

Current Sites of Infections and Types of Microorganisms in Patient with Febrile Neutropenia in Hematological Wards – Single Center Study

BACKGROUND: Febrile neutropenia occurs in more than 80% of patients with hematological malignances specially after chemotherapy cycles and an infectious source is identified in approximately 20–30%. Various bacterial, viral, and fungal pathogen contribute to the development of neutropenic fever and without prompt antibiotic therapy mortality rate can be as high as 70%. AIM: The objective of the study was to document the current sites of infection in patients with febrile neutropenia in hematological ward in Baghdad Teaching Hospital, the microorganisms and antibiotic susceptibly in culture positive cases and mortality rate in 1 week and 4 weeks after episode of fever. PATIENTS AND METHODS: One hundred cases of febrile neutropenia were evaluated in Hematological Ward of Baghdad Teaching Hospital from January 2019 to January 2020. Detailed history, physical examination, and laboratory investigations were conducted and statistical analysis of the results was done. RESULTS: One hundred cases of febrile neutropenia, mean age of presentation was 41.56 ± 10.5 years. Acute myeloid leukemia (36%) and acute lymphocytic leukemia (26%) were the most common underlying hematological disorder, followed by Aplastic Anemia, Non-Hodgkin Lymphoma, and Hodgkin Lymphoma. Temperature ranged from 38°C to 39°C with mean temperature of 38.4°C and most of the patient presented with short duration of fever, 57% had absolute neutrophil count below 150 cells/μL with mean duration of neutropenia was 14.01 days. Respiratory tract was the most common site of infection (52%) followed by urinary tract (18%) and in 16% had no obvious focus of infection. Thirty percent of cases were culture Gram-positive and Gram-negative microorganism which were more common 62.9% which were generally sensitive to Aminoglycosides while Gram-positive microorganism constituted 29.6% of isolated bacteria and were generally sensitive to vancomycin. No mortality documented 1 and 4 weeks after fever. CONCLUSION: We concluded that the most frequent sites of infection in patient with febrile neutropenia were respiratory tract followed by urinary tract infection, while 16% had undetermined source of infection. Thirty percent of patients had a positive blood culture with Escherichia coli being the most common infecting microorganism, Gram-negative microorganisms were more common than Gram-positive microorganism and fungal infection constituted about 6% of growth. Significant association was found between the fever and longer duration of neutropenia and the greater severity of neutropenia was observed. No mortality related to febrile neutropenia was documented.

The insertion site is the main risk factor for central venous catheter-related complications in patients with hematologic malignancies

Central venous catheters (CVC) placed either via the internal jugular vein (IJV) or the subclavian vein (SCV) are routinely used in patients with hematologic malignancies. In this retrospective study, we systematically compared CVC-associated complications for both insertion sites, IJV and SCV. Between January 2011 and June 2013, all consecutive patients (n = 87) were included with at least one CVC (n = 153; n = 94 IJV; n = 59 SCV) at our institution due to induction/consolidation for AML/ALL or autologous hematopoietic cell transplantation (HCT). Primary study endpoints were central line-associated (CLABSI), catheter-related (CRBSI) blood stream infections and local inflammation (LI) at the insertion site. CRBSI occurred earlier and more frequently in the IJV- versus the SCV-group with an incidence rate of CRBSI at day 15 of 10% versus 0% (p = .04) and a rate of CRBSI per 1000 CVC days of 5.7 versus 1.2. In addition, CLABSI was detected more often in IJV- compared to SCV-CVC (26% vs. 8%, p = .009). Conversely, LI occurred more frequently and earlier in SCV- versus IJV-CVC (88% vs. 56%, p < .0001) with a median time to LI of 9 versus 14 days (p < .0001). The strongest risk factor for the endpoints CRBSI, CLABSI, and LI was the insertion site. However, SCV insertion was a risk factor for LI (p = .001, HR: 2.0), insertion in the IJV a risk factor for CLABSI (p = .044, HR: 2.7) and CRBSI (p = .036, HR: 5.4). These results demonstrate a differential effect of the insertion site of CVC in neutropenic patients with a significantly reduced frequency of CVC-related blood stream infections in SCV-CVC.

Frequency of microbial isolates and pattern of antimicrobial resistance in patients with hematological malignancies: a cross-sectional study from Palestine

BACKGROUND

Infections are the main cause of death in patients with hematologic malignancies. This study aims to determine the microbial profile of infections in patients with hematologic malignancies and to determine the antimicrobial resistance patterns for these pathogens.

METHODS

A retrospective descriptive cross-sectional study was conducted from January 2018 to December 2019 at a large hematological center in Palestine. The medical data of hematologic malignancy patients with positive cultures were collected from the hematology/oncology department using the hospital information system, and data regarding the microbial isolates and their antimicrobial resistance were collected from the microbiology laboratory.

RESULTS

A total of 144 isolates were identified from different types of specimens, mostly blood samples. Of all isolates, 66 (45.8%) were gram-negative bacteria (GNB), 57 (39.6%) were gram-positive bacteria (GPB), and 21 (14.6%) were fungal isolates. The GNB that were most frequently isolated were Pseudomonas aeruginosa (27, 40.9%), followed by Escherichia coli (E. coli) (20, 30.3%). Fourteen isolates (24.6%) of GPB were Staphylococcus epidermidis followed by Enterococcus faecium (10, 17.5%) and Staphylococcus hemolyticus (10, 17.5%). The most frequent fungal pathogens were Candida species (20, 95.2%). GNB were found to be resistant to most antibiotics, mainly ampicillin (79.3%). Pseudomonas aeruginosa exhibited high resistance to ciprofloxacin (60%) and imipenem (59.3%). Among GPB, high resistance rates to oxacillin (91.1%) and amikacin (88.8%) were found. All isolated strains of Staphylococcus epidermidis were resistant to cephalosporins and oxacillin. Approximately half of the GNB isolates (34, 51.5%) were multi-drug resistant organisms (MDRO), and 16.7% (11 isolates) were difficult-to-treat resistance (DTR). Furthermore, 68.4% (39 isolates) of GPB were MDRO. The proportion of staphylococci (CoNS and S. aureus) resistant to oxacillin was 91.7%, while 88.6% of enterococci were resistant to vancomycin.

CONCLUSIONS

The findings of this study confirm the predominant microorganisms seen in patients with hematologic malignancies, and show a high percentage of antibiotic resistance. Policies regarding antibiotic use and proper infection control measures are needed to avert the ever-growing danger of antimicrobial resistance. This may be achieved by developing antibiotic stewardship programs and local guidelines based on the hospital's antibiogram.

Characteristics and Outcomes of Bloodstream Infections in a Tertiary-Care Pediatric Hematology-Oncology Unit: A 10-Year Study

Bloodstream infections (BSIs) after chemotherapy or hematopoietic stem cell transplantation (HSCT) are a leading cause of morbidity and mortality. Data on 154 BSIs that occurred in 111 onco-hematological patients (57 hematological malignancies, 28 solid tumors, and 26 non-malignant hematological diseases) were retrospectively collected and analyzed. Monomicrobial Gram-positive (GP), Gram-negative (GN), and fungal BSIs accounted for 50% (77/154), 38.3% (59/144), and 3.2% (5/154) of all episodes. Polymicrobial infections were 7.8% (12/154), while mixed bacterial-fungal infections were 0.6% (1/154). The most frequent GN isolates were Escherichia coli (46.9%), followed by Pseudomonas aeruginosa (21.9%), Klebsiella species (18.8%), and Enterobacter species (6.3%). Overall, 18.8% (12/64) of GN organisms were multidrug-resistant (seven Escherichia coli, three Klebsiella pneumoniae, and two Enterobacter cloacae), whereas GP resistance to glycopeptides was observed in 1% (1/97). Initial empirical antibiotic therapy was deemed inappropriate in 12.3% of BSIs (19/154). The 30-day mortality was 7.1% (11/154), while the bacteremia-attributable mortality was 3.9% (6/154). In multivariate analysis, septic shock was significantly associated with 30-day mortality (p = 0.0001). Attentive analysis of epidemiology and continuous microbiological surveillance are essential for the appropriate treatment of bacterial infections in pediatric onco-hematological patients.

Establishment and validation of a nomogram to predict the in-hospital death risk of nosocomial infections in cancer patients

Background

Attributed to the immunosuppression caused by malignancy itself and its treatments, cancer patients are vulnerable to developing nosocomial infections. This study aimed to develop a nomogram to predict the in-hospital death risk of these patients.

Methods

This retrospective study was conducted at a medical center in Northwestern China. The univariate and multivariate logistic regression analyses were adopted to identify predictive factors for in-hospital mortality of nosocomial infections in cancer patients. A nomogram was developed to predict the in-hospital mortality of each patient, with receiver operating characteristic curves and calibration curves being generated to assess its predictive ability. Furthermore, decision curve analysis (DCA) was also performed to estimate the clinical utility of the nomogram.

Results

A total of 1,008 nosocomial infection episodes were recognized from 14,695 cancer patients. Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (15.5%) was the most predominant causative pathogen. Besides, multidrug-resistant strains were discovered in 25.5% of cases. The multivariate analysis indicated that Eastern Cooperative Oncology Group Performance Status 3–4, mechanical ventilation, septic shock, hypoproteinemia, and length of antimicrobial treatment < 7 days were correlated with higher in-hospital mortality. Patients who received curative surgery were correlated with favorable survival outcomes. Ultimately, a nomogram was constructed to predict the in-hospital mortality of nosocomial infections in cancer patients. The area under the curve values of the nomogram were 0.811 and 0.795 in the training and validation cohorts. The calibration curve showed high consistency between the actual and predicted in-hospital mortality. DCA indicated that the nomogram was of good clinical utility and more credible net clinical benefits in predicting in-hospital mortality.

Conclusions

Nosocomial infections stay conjoint in cancer patients, with gram-negative bacteria being the most frequent causative pathogens. We developed and verified a nomogram that could effectively predict the in-hospital death risk of nosocomial infections among these patients. Precise management of high-risk patients, early recognition of septic shock, rapid and adequate antimicrobial treatment, and dynamic monitoring of serum albumin levels may improve the prognosis of these individuals.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13756-022-01073-3.

Bloodstream Infections in Patients with Hematologic Diseases: Causative Organisms and Factors Associated with Resistance

Background

Materials and Methods

Results

Conclusion

Retrospective Analysis of Bacterial Isolates during Blood Stream Infections in Children with Chemotherapy-induced Febrile Neutropenia: A Single Centre Experience

Introduction The recent advances in cancer treatment have resulted in significant improvement in the outcome of pediatric cancers. However, febrile neutropenia (FN) is the most important cause of mortality and morbidity in pediatric cancer patients and is a crucial limiting factor for the outcome. The greatest threat that we are facing is the emergence of pan drug-resistant (PDR) organisms.

Objectives To study bacterial organisms causing bloodstream infections (BSI) during febrile neutropenia episodes, their antibiotic sensitivity pattern, impact on treatment outcome during the intensive phase of chemotherapy, and the association between prior administration of antibiotics and emergence of multidrug-resistant organisms (MDR).

Materials and Methods This retrospective study was conducted in patients between the age group of 0 to 18 years who were treated for malignancies in the division of pediatric oncology at a tertiary center from August 2017 to December 2020. Blood cultures were collected under aseptic precautions, and they were processed as per the Clinical and Laboratory Standard Institute Guideline (CLSI) 2017.

Results A total of 122/159 (76.7%) patients were diagnosed to have hematological malignancies, and 37/159 (23.3%) patients were found to be suffering from solid tumors. A total of 309 episodes of FN were documented and 386 cultures were sent, out of which 87/386 (22.53%) cultures were positive for bacteria and 2/386 (2.2%) for fungi. Gram-negative isolates were seen in 51/87 (58.62%) cultures and Gram-positive in 36/87 (41.37%) cultures. Burkholderia cepacia and coagulase-negative Staphylococci (CONS) were the commonest found Gram-negative and Gram-positive bacteria, respectively. MDR bacterial strains were seen in 44/87 (50.57%) cultures and PDR strains in 8/87 (9.2%) cultures. Resistance was higher with Klebsiella species and CONS. There were six mortalities during the induction phase of acute leukemia treatment, out of which 4/6 (66.66%) were due to MDR infections, 1/6 (16.6%) due to fungal infection and chemotherapy refractoriness each.

Conclusion Proven bacterial infections were determined in 22.53% of febrile neutropenia episodes. Most BSI in patients with febrile neutropenia were caused by Gram-negative bacteria. Indiscriminate use of higher antibiotics before referral led to the emergence of MDR organisms, thus compromising the outcome. Our study emphasizes the fact that antibiotic stewardship is a crucial task to counter MDR bacteremia-related morbidity and mortality in neutropenic children.

Risk Factors for Infections, Antibiotic Therapy, and Its Impact on Cancer Therapy Outcomes for Patients with Solid Tumors

Infections represent a significant cause of morbidity and mortality in cancer patients. Multiple factors related to the patient, tumor, and cancer therapy can affect the risk of infection in patients with solid tumors. A thorough understanding of such factors can aid in the identification of patients with substantial risk of infection, allowing medical practitioners to tailor therapy and apply prophylactic measures to avoid serious complications. The use of novel treatment modalities, including targeted therapy and immunotherapy, brings diagnostic and therapeutic challenges into the management of infections in cancer patients. A growing body of evidence suggests that antibiotic therapy can modulate both toxicity and antitumor response induced by chemotherapy, radiotherapy, and especially immunotherapy. This article provides a comprehensive review of potential risk factors for infections and therapeutic approaches for the most prevalent infections in patients with solid tumors, and discusses the potential effect of antibiotic therapy on toxicity and efficacy of cancer therapy.

Bloodstream Infection and Endocarditis Caused by Staphylococcus aureus in Patients with Cancer: A Multicenter Cohort Study

INTRODUCTION

In a large cohort of patients with Staphylococcus aureus bloodstream infection (SABSI), we aimed to analyze the incidence and risk factors for infective endocarditis (IE) among patients with active cancer (PAC) in comparison with those without cancer (PWC).

METHODS

Multicenter cohort study of patients with SABSI admitted to two tertiary care hospitals, from 2011 to 2019. PAC were defined as those with an active solid organ cancer or hematological malignancies. SABSI and S. aureus IE were compared between PAC and PWC.

RESULTS

Among 978 episodes of SABSI, 217 (22.2%) occurred in PAC. PAC were younger, had fewer comorbidities, carried cardiac devices less often, and had less community-acquired SABSI than PWC. Compared to PWC, PAC more frequently had catheter-related SABSI, less IE (2.8% vs 10.9%, p < 0.001) and osteoarticular infection (2.3% vs 14.3%, p < 0.001). Independent risk factors for IE were cardiopathy (aOR 4.392, 95% CI 2.719-7.094) and persistent bacteremia (aOR 3.545, 95% CI 2.159-5.820). Thirty-day mortality was high, and similar between groups (24.2% vs 25.5%, p = 0.282).

CONCLUSIONS

PAC with SABSI developed IE less frequently than PWC did. This finding seems related to the differences in baseline characteristics and may have significant clinical implications, such as transesophageal echocardiography in PAC without cardiopathy or persistent bacteremia.

Impact of empirical antibiotic regimens on mortality in neutropenic patients with bloodstream infection presenting with septic shock

Objectives: We analyzed risk factors for mortality in febrile neutropenic patients with bloodstream infections (BSI) presenting with septic shock and assessed the impact of empirical antibiotic regimens. Methods: Multicenter retrospective study (2010-2019) of two prospective cohorts comparing BSI episodes in patients with or without septic shock. Multivariate analysis was performed to identify independent risk factors for mortality in episodes with septic shock. Results: Of 1563 patients with BSI, 257 (16%) presented with septic shock. Those patients with septic shock had higher mortality than those without septic shock (55% vs 15%, p<0.001). Gram-negative bacilli caused 81% of episodes with septic shock; gram-positive cocci, 22%; and Candida species 5%. Inappropriate empirical antibiotic treatment (IEAT) was administered in 17.5% of septic shock episodes. Empirical β-lactam combined with other active antibiotics was associated with the lowest mortality observed. When amikacin was the only active antibiotic, mortality was 90%. Addition of empirical specific gram-positive coverage had no impact on mortality. Mortality was higher when IEAT was administered (76% vs 51%, p=0.002). Age >70 years (OR 2.3, 95% CI 1.2-4.7), IEAT for Candida spp. or gram-negative bacilli (OR 3.8, 1.3-11.1), acute kidney injury (OR 2.6, 1.4-4.9) and amikacin as the only active antibiotic (OR 15.2, 1.7-134.5) were independent risk factors for mortality, while combination of β-lactam and amikacin was protective (OR 0.32, 0.18-0.57). Conclusions: Septic shock in febrile neutropenic patients with BSI is associated with extremely high mortality, especially when IEAT is administered. Combination therapy including an active β-lactam and amikacin results in the best outcomes.

Ofloxacin@Doxorubicin-Epirubicin functionalized MCM-41 mesoporous silica-based nanocarriers as synergistic drug delivery tools for cancer related bacterial infections

Mesoporous silica nanoparticles (MNs) emerged as new promising drug-delivery platforms capable to overcome resistance in bacteria. Dual loading of drugs on these nanocarriers, exploiting synergistic interactions between the nanoparticles and the drugs, could be considered as a way to increase the efficacy against resistant bacteria with a positive effect even at very low concentrations. Considering that patients with cancer are highly susceptible to almost any type of bacterial infections, in this work, nanocarriers mesoporous silica-based, MNs and MNs@EPI were synthetized and submitted to single and/or dual loading of antibiotics (ofloxacin - OFLO) and anticancer drugs (Doxorubicin - DOX; Epirubicin - EPI), and investigated regarding their antibacterial activity against Escherichia coli, Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), Enterococcus faecalis and Pseudomonas aeruginosa. Formulations containing ofloxacin such as MNs-OFLO, MNs-EPI + OFLO, MNs-DOX + OFLO and MNs@EPI + OFLO, present antibacterial activity in all bacterial strains tested. All these are more effective in E.coli with MIC and MBC values for MNs-OFLO, MNs-EPI + OFLO and MNs-DOX + OFLO of around 1 and 2 µg_nanomaterial/mL, corresponding to ofloxacin concentrations of 0.03, 0.02 and 0.04 µg/mL, respectively. In the cocktail formulations the conjugation of epirubicin with ofloxacin presents a more effective antibacterial activity with more than 3-fold reduction of ofloxacin concentration when comparing to the single ofloxacin system. By far, the most effective synergistic effect was obtained for the system where epirubicin was functionalized at nanoparticles surface (MNs@EPI), where a 40-fold and 33-fold reductions of ofloxacin concentration were obtained, in P. aeruginosa in comparison to the MNs-OFLO and MNs-EPI + OFLO systems, respectively. These effects are shown in all bacterial strains tested, even in strains that have acquired resistance mechanisms, such as MRSA.