Recent changes in bacteremia in patients with cancer: a systematic review of epidemiology and antibiotic resistance. Eur J Clin Microbiol Infect Dis. 2013;32:841-850. [PMID: 23354675 DOI: 10.1007/s10096-013-1819-7]

Risk factors for resistant gram-positive bacteremia in febrile neutropenic patients with cancer

BACKGROUND

Gram-positive bacteria are frequently resistant to empirical beta-lactams in febrile neutropenic patients with cancer. As microbiology and antibiotic susceptibility changes, we reevaluated the risk factors for resistant Gram-positive bacteremia in febrile neutropenic patients with cancer.

METHODS

Episodes of bacteremic febrile neutropenia in Seoul National University Hospital from July 2019 to June 2022 were reviewed. Resistant Gram-positive bacteria were defined as a pathogen susceptible only to glycopeptide or linezolid in vitro (e.g., methicillin-resistant staphylococci, penicillin-resistant viridans streptococci, and ampicillin-resistant enterococci). Episodes were compared to identify independent risk factors for resistant Gram-positive bacteremia.

RESULTS

Of 225 episodes, 78 (34.7%) involved resistant Gram-positive bacteremia. Multivariate analysis revealed that breakthrough bacteremia while being administered antibiotics (adjusted odds ratio [aOR], 6.794; 95% confidence interval [95% CI], 3.130-14.749; P < 0.001) and catheter-related infection (aOR 4.039, 95% CI 1.366-11.946; P = 0.012) were associated with resistant Gram-positive bacteremia. Chronic liver disease (aOR 0.231, 95% CI 0.059-0.905; P = 0.035) and hypotension at bacteremia (aOR 0.454, 95% CI 0.218-0.945; P = 0.035) were inversely associated with resistant Gram-positive bacteremia.

CONCLUSIONS

Resistant Gram-positive bacteria should be considered in breakthrough bacteremia and catheter-related infection in febrile neutropenic patients with cancer.

Recent updates in treating carbapenem-resistant infections in patients with hematological malignancies

INTRODUCTION

Patients with hematological malignancies (PHMs) are at increased risk for infections caused by carbapenem-resistant organisms (CROs) due to frequent exposure to broad-spectrum antibiotics and prolonged hospital stays. These infections result in high mortality and morbidity rates along with delays in chemotherapy, longer hospitalizations, and increased health care costs.

AREAS COVERED

Treatment alternatives for CRO infections in PHMs.

EXPERT OPINION

The best available treatment option for KPC and OXA-48 producers is ceftazidime/avibactam. Imipenem/cilastatin/relebactam and meropenem/vaborbactam remain as the alternative options. They can also be used as salvage therapy in KPC-positive Enterobacterales infections resistant to ceftazidime/avibactam, if in vitro susceptibility is shown. Treatment of metallo-β-lactamase producers is an unmet need. Ceftazidime/avibactam plus aztreonam or aztreonam/avibactam seems to be the most reliable option for metallo-β-lactamase producers. As a first-line option for carbapenem-resistant Pseudomonas aeruginosa infections, ceftolozane/tazobactam is preferable and ceftazidime/avibactam and imipenem/cilastatin/relebactam constitute alternative regimens. Although sulbactam/durlobactam is the most reliable option against carbapenem-resistant Acinetobacter baumannii infections, its utility as monotherapy and in PHMs is not yet known. Cefiderocol can be selected as a 'last-resort' option for CRO infections. New risk score models supported by artificial intelligence algorithms can be used to predict the exact risk of infections in previously colonized patients.

Predictors and outcomes of multi-drug-resistant gram-negative bacteremia in patients with cancer: A retrospective cohort study at a tertiary cancer center in Oman

Objectives

This study aimed to delineate the characteristics and outcomes of gram-negative bacteremia (GNB) in oncology patients; analyze the risk factors for multi-drug-resistant (MDR) GNB; and assess its impact on the recurrence of bloodstream infection (BSI), hospital stay, and 30-day mortality.

Methods

Data, including demographics, clinical features, common cancers, and microbiologic findings, were collected retrospectively from electronic medical records of patients admitted with solid tumors and BSI episodes between January and December 2022. Fisher's exact tests were used to determine the effect of MDR-GNB on 30-day mortality and BSI recurrence. The Wilcoxon rank-sum test assessed the differences in the length of hospital stay. Logistic regression models identified the risk factors for MDR-GNB.

Results

Among 1074 patients, 77 episodes of GNB bacteremia occurred in 59 individuals (47% male, median age 57.4 years). Of these, 37 (48%) were MDR-GNB. Carbapenem resistance was noted in 9.1% of GNB episodes. Previous antibiotic use was significantly associated with MDR-GNB (odds ratio 7.82; 95% confidence interval 2.52-24). MDR-GNB was linked to longer hospital stays (median 23 vs 10.5 days, P = 0.003) and higher recurrence rates than non-MDR-GNB (35.13% vs 5.0%, P <0.001). However, 30-day mortality did not significantly differ between the groups (35.14% vs 32.5%, P = 0.81).

Conclusion

Previous antibiotic use predicted MDR-GNB in patients with solid tumor. MDR-GNB bacteremia increased the length of hospital stay and risk of recurrence compared with non-MDR-GNB bacteremia.

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.

Oncology Intensive Care Units: Distinguishing Features and Clinical Considerations

The rapidly advancing field of cancer therapeutics has led to increased longevity among cancer patients as well as increasing complexity of cancer-related illness and associated comorbid conditions. As a result, institutions and organizations that specialize in the in-patient care of cancer patients have similarly evolved to meet the constantly changing needs of this unique patient population. Within these institutions, the intensive care units that specialize in the care of critically ill cancer patients represent an especially unique clinical resource. This article explores some of the defining and distinguishing characteristics associated with oncology ICUs.

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.

Hospital-acquired bloodstream infections in patients with cancer: current knowledge and future directions

Patients with cancer experience higher rates of preventable harm from hospital-acquired bloodstream infections (haBSIs) and central-line-associated bloodstream infections (CLABSIs) compared with the general hospital population. The prevention of haBSIs and CLABSIs in patients with cancer is an urgent priority, and requires standardized surveillance and reporting efforts. The application of haBSI and CLABSI definitions, classification systems and surveillance strategies for patients with cancer is complex, and there is wide variation in clinical practice. Existing systems were not designed explicitly for patients with cancer, and have different strengths and weaknesses in the cancer setting. For these reasons, epidemiological estimates of haBSIs and CLABSIs in patients with cancer also require careful interpretation. This complexity can be a barrier to identifying appropriate targets for intervention and reducing preventable harm. This review provides an overview of key concepts and challenges in haBSI surveillance and prevention specific to patients with cancer. In addition, this review summarizes the strengths and weaknesses of commonly used surveillance definitions and denominators in the setting of cancer care; existing surveillance practice; epidemiology of haBSIs and CLABSIs; prevention strategies; and current knowledge gaps. A global collaborative effort to harmonize the surveillance of hospital-acquired infections in patients with cancer would be invaluable to improve the accuracy and utility of existing data, advance efforts to prevent hospital-acquired infections, and improve patient safety.

In vitro activity of cefepime/taniborbactam and comparator agents against Gram-negative bacterial bloodstream pathogens recovered from patients with cancer

Background

Taniborbactam is a β-lactamase inhibitor that, when combined with cefepime, may offer a potential treatment option for patients with serious and resistant Gram-negative bacterial (GNB) pathogens.

Objectives

This study evaluated in vitro activity of cefepime/taniborbactam and comparator agents against GNB pathogens isolated from patients with cancer at our institution.

Methods

A total of 270 GNB pathogens (2019-23) isolated from patients with cancer were tested against cefepime/taniborbactam and comparator agents commonly used for these patients. CLSI-approved broth microdilution methods were used. MIC50, MIC90, MIC range and percentage of susceptibility calculations were made using FDA breakpoints when available.

Results

Cefepime/taniborbactam showed highly potent activity against tested Enterobacterales, including isolates producing ESBLs and carbapenem-resistant Enterobacterales. At a provisional breakpoint of ≤16/4 mg/L, cefepime/taniborbactam inhibited most tested species of GNB pathogens, with overall 98.9% susceptibility, which was significantly (P < 0.0001) higher than the susceptibility of the GNB isolates to all other tested comparator agents, ranging from 39.6% for cefepime to 86.3% for ceftazidime/avibactam.

Conclusions

Our results showed that taniborbactam in combination with cefepime improved in vitro activity against GNB pathogens isolated from patients with cancer, including MDR Pseudomonas aeruginosa, carbapenem-resistant Enterobacterales, ESBL-producing Enterobacterales and Stenotrophomonas maltophilia isolates, with highest activity compared with all tested comparator agents, including other β-lactam/β-lactamase inhibitor combinations. Further studies are warranted to explore the efficacy of cefepime/taniborbactam for empirical initial treatment of GNB infections in cancer patients with high rates of febrile neutropenia requiring hospitalization.

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.

Bacterial Isolates and Characteristics of Children With Febrile Neutropenia on Treatment for Cancer at a Tertiary Hospital in Western Kenya

PURPOSE

This study aimed to identify the patient characteristics of children with febrile neutropenia, the associated bacterial organisms, and their sensitivity patterns.

MATERIALS AND METHODS

A descriptive cross-sectional study was conducted at the Moi Teaching and Referral Hospital (MTRH) pediatric oncology ward, from June 2021 to April 2022. A total of 110 children who developed fever and neutropenia during chemotherapy were enrolled. Blood samples for culture were collected aseptically. Patient characteristics were presented in frequency tables. Antimicrobial sensitivity patterns were plotted in tables against the bacterial isolates cultured. Chi-square/Fisher's exact test was used to determine any association between patient characteristics, bacterial growth, and antimicrobial sensitivity.

RESULTS

The majority (n = 66; 60%) were males. The median age was 6.3 years (standard deviation, 3.7). The majority of patients 71 (64.5%) had hematologic malignancies, the most common being AML. There was a significant association between severity of neutropenia and hematologic malignancies (P = .028). In total, 31/110 (28.2%) blood cultures were positive for bacterial growth. Gram-positive bacteria were more frequent (n = 20; 58.1%). The most common organism was Escherichia coli (n = 6; 18.2%), followed by Staphylococcus aureus (n = 5; 15.2%). All the isolates were sensitive to linezolid and vancomycin and also showed good sensitivity toward meropenem (n = 10/11; 90.9%). High resistance to cephalosporins was noted with ceftriaxone (n = 5/6; 83.3%), cefepime (n = 4/7; 57.1%), and ceftazidime (n = 3/4; 75%).

CONCLUSION

The most common malignancy associated with febrile neutropenia was AML. Gram-positive bacteria were the most common isolates. There was high resistance to cephalosporins.

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.

Bloodstream Infection and Colorectal Cancer Risk in Queensland Australia, 2000-2019

BACKGROUND

Bloodstream infections may occur as a complication of colorectal cancer or be a marker for its occult presence. The objectives of this study were to quantify the overall and etiology-specific risks for incident colorectal cancer-associated bloodstream infection.

METHODS

Population-based surveillance for community-onset bloodstream infection was conducted among adults aged 20 years and older in Queensland, Australia between 2000 and 2019. Statewide databases were used to identify patients with incident colorectal cancer and collect clinical and outcome information.

RESULTS

After exclusion of 1794 patients with prior colorectal cancer, a cohort of 84,754 patients was assembled, of which 1030 had colorectal cancer-associated bloodstream infection and 83,724 had no colorectal cancer. Bloodstream infection was associated with a 16-fold annualized increased risk for diagnosis of colorectal cancer (incidence rate ratio 16.1; 95% confidence interval [CI], 15.1-17.1) in the adult population. Patients who had colorectal cancer-associated bloodstream infection were more likely to be older and male, have hospital-onset and polymicrobial infections, and have fewer non-cancer-related comorbidities. The organisms associated with highest risk for colorectal cancer included Clostridium species (relative risk [RR] 6.1; 95% CI, 4.7-7.9); especially C. septicum (RR 25.0; 95% CI, 16.9-35.7), Bacteroides species (RR 4.7; 95% CI, 3.8-5.8); especially B. ovatus (RR 11.8; 95% CI, 2.4-34.5), Gemella species (RR 6.5; 95% CI, 3.0-12.5), Streptococcus bovis group (RR 4.4; 95% CI, 2.7-6.8); especially S. infantarius subsp. coli (RR 10.6; 95% CI, 2.9-27.3), Streptococcus anginosus group (RR 1.9; 95% CI, 1.3-2.7), and Enterococcus species (RR 1.4; 95% CI, 1.1-1.8).

CONCLUSION

Although much attention has been afforded to S. bovis group over the past decades, there are many other isolates associated with higher risk for colorectal cancer-associated bloodstream infections.

Bacterial Sequencing Reads in Blood Exome Files from Melanoma and Cervical Cancer Patients are Associated with Cancer Recurrence

Bacteremia poses great risk for morbidity and mortality for immunocompromised cancer patients. Although the presence of bacteria within solid tumors is gaining greater attention, few studies have analyzed species of bacteria in the blood and their effect on cancer clinical outcomes. Using the Kraken 2 taxonomic profiling tool, we classified bacteria present in blood and primary tumors of cervical cancer and melanoma cases. The Cancer Genome Atlas (TCGA) melanoma blood exome files with Pseudomonas species were found to represent a worse disease-free survival (DFS) probability, while a worse overall survival (OS) result was evidenced for both the TCGA and Moffitt Cancer Center melanoma datasets. Cervical cancer cases with reads representing the Bradyrhizobium genus and Bradyrhizobium sp. BTAi1 found in blood and tumor exome files were found to have lower DFS. Additionally, reduced DFS and OS were observed for cervical cancer cases positive for Bacteroides species including Bacteroides fragilis. This study provides novel evidence and a novel approach for indicating that bacteria in blood is associated with cancer recurrence. These findings may guide the development of more efficient prognostic and screening tools related to bacterial blood infections of melanoma and cervical cancer patients.

Infections in Children with Cancer Admitted in an Oncology Reference Hospital: A Cross-sectional Study

Pediatric oncology patients are usually immunosuppressed due to factors such as the neoplasm and its treatment, making them more susceptible to infections. This article aims to determine the infection profile of pediatric oncology patients admitted to an oncology reference hospital in Natal, Rio Grande do Norte, Brazil. A retrospective and cross-sectional study was conducted, collecting data from patients hospitalized due to infection in a pediatric oncology unit exclusively for the Brazilian public health system, spanning from 2018 to 2021. A total of 168 episodes of infections were identified in 96 patients, resulting in 157 hospitalizations. Among the patients with infections, 62.4% had hematological malignancies, and out of these cases, 74.6% specifically had Acute Lymphoid Leukemia. The Escherichia coli (31.9%) was the most prevalent microorganism isolated from the samples. Multidrug-resistant microorganisms accounted for 52% of all identified microorganisms. Fluoroquinolones and beta-lactam were the most prevalent antibiotic classes in the analyzed antibiograms. Factors such as Sex, type of cancer, chemotherapy in the last 30 days, were found to be associated with the occurrence of infection (p < 0.05). Conducting epidemiological studies regarding infections in pediatric oncology is crucial to development of empirical protocols, and the implementation of strategies to better control future infections.

[Value of metagenomic next-generation sequencing in children with hematological malignancies complicated with infections]

OBJECTIVES

To explore the value of metagenomic next-generation sequencing (mNGS) in the pathogen identification in children with hematological malignancies complicated with infections.

METHODS

A retrospective analysis was conducted on clinical data and pathogenic test results of 43 children with hematological malignancies who underwent microbial culture and mNGS due to infections in the Third Xiangya Hospital of Central South University between June 2020 and July 2022. Differences in detection rates and characteristics of pathogenic microorganisms detected by mNGS and microbial culture were compared.

RESULTS

A total of 54 specimens were examined, and the overall detection rate of pathogen by mNGS (80%, 43/54) was significantly higher than that by microbial culture (30%, 16/54) (P<0.001). The most commonly detected infection type by mNGS was viral infection, followed by fungal infection combined viral infection, while that by microbial culture was bacterial infection, followed by fungal infection. The detection rate of fungi by mNGS (33%, 18/54) was higher than that by microbial culture (6%, 3/54) (P<0.001). The detection rate of two or more pathogenic microorganisms by mNGS was higher at 48% compared to microbial culture at 9% (P<0.05). The detection rate of two or more types of pathogenic microorganisms by mNGS was also significantly higher at 33% compared to microbial culture at 2% (P<0.05). The most commonly detected bacteria and fungi by mNGS were Pseudomonas aeruginosa and Candida tropicalis, respectively, in peripheral blood, while Streptococcus pneumoniae and Pneumocystis jirovecii were most commonly detected in bronchoalveolar lavage fluid. Treatment adjustments based on mNGS results were beneficial for 35% (15/43) of the cases.

CONCLUSIONS

mNGS has a higher detection rate than microbial culture and has obvious advantages in diagnosing mixed and fungal infections, making it a useful supplementary diagnostic method to microbial culture.

Examining the Evidence for Escalating Antimicrobial Regimens in Febrile Oncology and Hematopoietic Stem Cell Transplant Patients Admitted to the PICU: An Observational Study

OBJECTIVES

To examine whether escalating antimicrobial treatment in pediatric oncology and hematopoietic cell transplantation (HSCT) patients admitted to the PICU is supported by culture data or affects patient outcomes.

DESIGN

Retrospective cross-sectional study.

SETTING

Quaternary care PICU.

PATIENTS

Patients younger than 18 years old who were admitted to the PICU at Boston Children's Hospital from 2012 to 2017 with a diagnosis of cancer or who had received HSCT and who had suspected sepsis at the time of PICU admission.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 791 PICU admissions for 544 patients that met inclusion criteria, 71 (9%) had escalation of antimicrobial therapy. Median Pediatric Logistic Organ Dysfunction (PELOD) score was higher in the escalation group (4 vs 3; p = 0.01). There were 14 admissions (20%) with a positive culture in the escalation group and 110 (15%) in the no escalation group ( p = 0.31). In the escalation group, there were only 2 (3%) cultures with organisms resistant to the initial antimicrobial regimen, compared with 28 (4%) cultures with resistant organisms in the no escalation group ( p = 1). Mortality in the escalation group was higher (17%) compared with the nonescalation group (5%; p < 0.001). The escalation group had more acute kidney injury (AKI) (25%) during treatment compared with the no escalation group (15%; p = 0.04), although this difference was not statistically significant when controlling for age, neutropenia, and PELOD-2 score (odds ratio, 1.75; 95% CI, 0.95-3.08; p = 0.06).

CONCLUSIONS

Few patients who had escalation of antimicrobials proved on culture data to have an organism resistant to the initial antimicrobials, and more patients developed AKI during escalated treatment. While the escalation group likely represents a sicker population, whether some of these patients would be safer without escalation of antimicrobial therapy warrants further study.

The Applicability of a 2-Transcript Signature to Identify Bacterial Infections in Children with Febrile Neutropenia

Febrile neutropenia is a common complication during chemotherapy in paediatric cancer care. In this setting, clinical features and current diagnostic tests do not reliably distinguish between bacterial and viral infections. Children with cancer (n = 63) presenting with fever and neutropenia were recruited for extensive microbiological and blood RNA sampling. RNA sequencing was successful in 43 cases of febrile neutropenia. These were classified as having probable bacterial infection (n = 17), probable viral infection (n = 13) and fever of unknown origin (n = 13) based on microbiological defined infections and CRP cut-off levels. RNA expression data with focus on the 2-transcript signature (FAM89A and IFI44L), earlier shown to identify bacterial infections with high specificity and sensitivity, was implemented as a disease risk score. The median disease risk score was higher in the probable bacterial infection group, -0.695 (max 2.795; min -5.478) compared to the probable viral infection group -3.327 (max 0.218; min -7.861), which in ROC analysis corresponded to a sensitivity of 0.88 and specificity of 0.54 with an AUC of 0.80. To further characterise the immune signature, analysis of significantly expressed genes and pathways was performed and upregulation of genes associated to antibacterial responses was present in the group classified as probable bacterial infection. Our results suggest that the 2-transcript signature may have a potential use as a diagnostic tool to identify bacterial infections in immunosuppressed children with febrile neutropenia.

Antimicrobial Stewardship on Patients with Neutropenia: A Narrative Review Commissioned by Microorganisms

The emergence of antibiotic resistance poses a global health threat. High-risk patients such as those with neutropenia are particularly vulnerable to opportunistic infections, sepsis, and multidrug-resistant infections, and clinical outcomes remain the primary concern. Antimicrobial stewardship (AMS) programs should mainly focus on optimizing antibiotic use, decreasing adverse effects, and improving patient outcomes. There is a limited number of published studies assessing the impact of AMS programs on patients with neutropenia, where early appropriate antibiotic choice can be the difference between life and death. This narrative review updates the current advances in strategies of AMS for bacterial infections among high-risk patients with neutropenia. Diagnosis, drug, dose, duration, and de-escalation (5D) are the core variables among AMS strategies. Altered volumes of distribution can make standard dose regimens inadequate, and developing skills towards a personalized approach represents a major advance in therapy. Intensivists should partner antibiotic stewardship programs to improve patient care. Assembling multidisciplinary teams with trained and dedicated professionals for AMS is a priority.

Clinical outcomes of antimicrobial resistance in cancer patients: a systematic review of multivariable models

BACKGROUND

Infections are major causes of disease in cancer patients and pose a major obstacle to the success of cancer care. The global rise of antimicrobial resistance threatens to make these obstacles even greater and hinder continuing progress in cancer care. To prevent and handle such infections, better models of clinical outcomes building on current knowledge are needed. This internally funded systematic review (PROSPERO registration: CRD42021282769) aimed to review multivariable models of resistant infections/colonisations and corresponding mortality, what risk factors have been investigated, and with what methodological approaches.

METHODS

We employed two broad searches of antimicrobial resistance in cancer patients, using terms associated with antimicrobial resistance, in MEDLINE and Embase through Ovid, in addition to Cinahl through EBSCOhost and Web of Science Core Collection. Primary, observational studies in English from January 2015 to November 2021 on human cancer patients that explicitly modelled infection/colonisation or mortality associated with antimicrobial resistance in a multivariable model were included. We extracted data on the study populations and their malignancies, risk factors, microbial aetiology, and methods for variable selection, and assessed the risk of bias using the NHLBI Study Quality Assessment Tools.

RESULTS

Two searches yielded a total of 27,151 unique records, of which 144 studies were included after screening and reading. Of the outcomes studied, mortality was the most common (68/144, 47%). Forty-five per cent (65/144) of the studies focused on haemato-oncological patients, and 27% (39/144) studied several bacteria or fungi. Studies included a median of 200 patients and 46 events. One-hundred-and-three (72%) studies used a p-value-based variable selection. Studies included a median of seven variables in the final (and largest) model, which yielded a median of 7 events per variable. An in-depth example of vancomycin-resistant enterococci was reported.

CONCLUSIONS

We found the current research to be heterogeneous in the approaches to studying this topic. Methodological choices resulting in very diverse models made it difficult or even impossible to draw statistical inferences and summarise what risk factors were of clinical relevance. The development and adherence to more standardised protocols that build on existing literature are urgent.

Candida bloodstream infection in patients with cancer: A retrospective analysis of an 11-year period

BACKGROUND

Candida bloodstream infection (CBSI) is a growing problem among patients with cancer.

AIM

To describe the main clinical and microbiological characteristics in patients with cancer who suffer CBSI.

METHODS

We reviewed the clinical and microbiological characteristics of all patients with CBSI diagnosed between January 2010 and December 2020, at a tertiary-care oncological hospital. Analysis was done according to the Candida species found. Multivariate logistic regression analysis was used to determine the risk factors associated with 30-day mortality.

RESULTS

There were 147 CBSIs diagnosed, 78 (53%) in patients with hematologic malignancies. The main Candida species identified were Candida albicans (n=54), Candida glabrata (n=40) and Candida tropicalis (n=29). C. tropicalis had been mainly isolated from patients with hematologic malignancies (79.3%) who had received chemotherapy recently (82.8%), and in patients with severe neutropenia (79.3%). Seventy-five (51%) patients died within the first 30 days, and the multivariate analysis showed the following risk factors: severe neutropenia, a Karnofsky Performance Scale score under 70, septic shock, and not receiving appropriate antifungal treatment.

CONCLUSIONS

Patients with cancer who develop CBSI had a high mortality related with factors associated with their malignancy. Starting an empirical antifungal therapy the soonest is essential to increase the survival in these patients.

Bacterial Infections and Cancer: Exploring This Association And Its Implications for Cancer Patients

Bacterial infections are common in the etiology of human diseases owing to the ubiquity of bacteria. Such infections promote the development of periodontal disease, bacterial pneumonia, typhoid, acute gastroenteritis, and diarrhea in susceptible hosts. These diseases may be resolved using antibiotics/antimicrobial therapy in some hosts. However, other hosts may be unable to eliminate the bacteria, allowing them to persist for long durations and significantly increasing the carrier's risk of developing cancer over time. Indeed, infectious pathogens are modifiable cancer risk factors, and through this comprehensive review, we highlight the complex relationship between bacterial infections and the development of several cancer types. For this review, searches were performed on the PubMed, Embase, and Web of Science databases encompassing the entirety of 2022. Based on our investigation, we found several critical associations, of which some are causative: Porphyromonas gingivalis and Fusobacterium nucleatum are associated with periodontal disease, Salmonella spp., Clostridium perfringens, Escherichia coli, Campylobacter spp., and Shigella are associated with gastroenteritis. Helicobacter pylori infection is implicated in the etiology of gastric cancer, and persistent Chlamydia infections present a risk factor for the development of cervical carcinoma, especially in patients with the human papillomavirus (HPV) coinfection. Salmonella typhi infections are linked with gallbladder cancer, and Chlamydia pneumoniae infection is implicated in lung cancer, etc. This knowledge helps identify the adaptation strategies used by bacteria to evade antibiotic/antimicrobial therapy. The article also sheds light on the role of antibiotics in cancer treatment, the consequences of their use, and strategies for limiting antibiotic resistance. Finally, the dual role of bacteria in cancer development as well as in cancer therapy is briefly discussed, as this is an area that may help to facilitate the development of novel microbe-based therapeutics as a means of securing improved outcomes.

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.

Increased incidence rates of positive blood cultures shortly after chemotherapy compared to radiotherapy among individuals treated for solid malignant tumours

BACKGROUND

Cancer treatments suppress immune function and are associated with increased risk of infections, but the overall burden of serious infectious diseases in treated patients has not been clearly elucidated.

METHODS

All patients treated for solid malignant tumours with radiotherapy (RT) and/or standard first-line chemotherapy (C) at the Department of Oncology at Rigshospitalet between 01/1/2010 and 31/12/2016 were included. Patients were followed from treatment initiation until the first of new cancer treatment, 1 year after treatment initiation, end of follow-up or death. Incidence rates (IR) of positive blood culture (PBC) per 1000 person-years follow-up (PYFU) were calculated.

FINDINGS

12,433 individuals were included, 3582 (29%), 6349 (51%), and 2502 (20%) treated with RT, C, or both RT & C, respectively, contributing 8182 PYFU. 429 (3%) individuals experienced 502 unique episodes of PBC, incidence rate (95% CI) 52.43 (47.7, 57.6) per 1000 PYFU. The 30-day mortality rate after PBC was 24% independent of treatment modality. Adjusted incidence rate ratios in the first 3 months (95% CI) after PBC significantly varied by treatment: 2.89 (1.83, 4.55) and 2.52 (1.53, 4.14) for C and RT & C compared to RT. Escherichia coli (n = 127, 25%) was the top microorganism identified.

INTERPRETATION

PBCs are not common, but when they occur, mortality is high.

Risk of Bacterial, Viral, and Fungal Infections in Patients With Solid Malignant Tumors Treated With Curative Intent Radiation Therapy

Purpose

The incidence, etiology, and association of infections with radiation therapy (RT)-induced lymphopenia in patients with solid tumors is not well elucidated.

Methods and Materials

We identified possible, probable, and definite infections caused by bacteria, fungi, and viruses, combining data on medication, microbiology, and diagnoses. Definite infections had either a diagnosis or a positive microbiological isolation. We analyzed the incidence and adjusted incidence-rate ratio of infections in the year after the start of RT among patients who received RT plus chemotherapy and RT monotherapy, by type of infection and according to the degree of RT-induced lymphopenia.

Results

A total of 4450 of 6334 (70.3%) patients experienced 11264 infections overall; 1424 (22.5%) patients developed 2104 definite infections in the first year after RT. Infections were more frequent among patients who received RT plus chemotherapy (2590 of 3469; incidence: 16.5 [95% confidence interval {CI}, 16.1-17.0], per 100 patient-years) compared with patients who received RT monotherapy (1860 of 2865; incidence: 12.7 [95% CI, 12.3-13.2]). The incidence of infection was highest in the first 3 months overall (28.2 vs 18.0 in patients who received RT plus chemotherapy compared with those who received RT monotherapy) and for definite infections (4.7 vs 3.8). The proportion of specific bacterial infections were similar among patients who received RT plus chemotherapy versus those who received RT monotherapy. Urinary tract infections were the most frequent (51.2% vs 56.2%), followed by pneumonias (24.1% vs 22.4%). Viral and fungal infections were more frequent among patients who received RT plus chemotherapy, but they were uncommon. In multivariable analyses, patients who received RT plus chemotherapy with a lymphopenia grade of 1-2 or ≥3 versus no lymphopenia at end of RT had an increased risk of bacterial infections 0 to 3 months after RT (incidence rate ratio, 1.45 [95% CI, 1.06-1.97] and 1.71 [95% CI, 1.26-2.34], respectively). Limiting to definite bacterial infections, the incidence rate ratio for lymphopenia grade ≥3 versus no lymphopenia was 2.66 (95% CI, 1.40-5.03).

Conclusions

The incidence of bacterial infections 0 to 3 months after RT plus chemotherapy for solid tumors was high, especially among patients with RT-induced lymphopenia grade 1-2 and ≥3.

Alarming Antibiotic Resistance in Pediatric Oncology Patients: A Three-Year Prospective Cohort Study from Oman

Background

Bloodstream infections (BSI) are severe and challenging oncological complications, with a consequent high morbidity and mortality in the immunocompromised. We reviewed the profile and susceptibility of bacteria associated with infections in children under 13 years of age receiving chemotherapy.

Methods

Prospective cohort study of pediatric oncology patients was conducted between January 2015 and October 2017 at the Royal Hospital in Oman. Patient demographics, clinical data, laboratory parameters, microbial etiology and susceptibility, and outcomes were retrieved and analyzed.

Results

A total of 74 episodes of positive bacterial blood cultures were detected in 38 oncology patients (positive blood culture rate of 51%). Fifty-seven percent were positive for gram-negative organisms with Klebsiella (21%) being the most common gram-negative organism cultured, and the most common gram-positive organism was Staphylococcus (coagulase negative Staphylococcus (CONs) and S. Aureus) (30%). The majority of patients had gastrointestinal complaints (74%), and almost half (51%) had prolonged periods of neutropenia (>7 days). One third of gram-negative organisms were resistant to four or more antibiotics with a major resistance of 31% to piperacillin-tazobactam. Of the gram-positive organisms, 38% were resistant to at least four antibiotics and 30% were pan-resistant (except for vancomycin).

Conclusion

The gram-negative organisms were dominant in BSIs with Klebsiella being the most common culprit. Bacteremia was prevalent, however, high resistance to first-line antibiotics was documented amongst gram-negative isolates, demanding strategies to ensure our patients’ safety.

Factors Associated with Gram-Negative Bacteremia and Mortality in Neutropenic Patients with Hematologic Malignancies in a High-Resistance Setting

Objective

Patients with hematological malignancies (HMs) have a substantial incidence of febrile neutropenic episodes. Gram-negative bacteremia (GNB) is still the major cause of these episodes. We evaluated the factors associated with GNB and mortality of bacteremic patients with HMs in a high-resistance setting.

Materials and Methods

We conducted a prospective cohort study from March 2018 to June 2019 with 66 bacteremic and 132 non-bacteremic patients. Regression analyses were used to identify factors associated with GNB and 30-day mortality.

Results

The mean age was 53.83±15.21 years, and 129 (65.2%) of the patients were male. In multivariable analysis, factors independently associated with GNB were male gender, duration of hospitalization and neutropenia before the febrile neutropenic episode, leukemias and allogeneic transplant recipients, radiotherapy, receiving glucocorticosteroids, colonization with resistant microorganisms. All-cause mortality and 30-day mortality were 47.0% and 30.3% in cases of GNB, compared to non-bacteremic controls 25.0% and 10.6%, respectively. Sepsis, duration of hospitalization before the febrile neutropenic episode, carbapenem-resistant GNB, and inappropriate empirical antibiotic treatment was found as factors associated with 30-day mortality. Prior antibiotic exposure particularly beta-lactamase inhibitor combinations and carbapenems during the past 30 days was more frequent in the bacteremic group. An increasing trend was observed in multidrug-resistant (MDR) bacteria (p=0.03) and carbapenem-resistant Enterobacterales (p=0.02) over the years.

Conclusion

By considering the risk factors associated with GNB and 30-day mortality that we detected in our study among neutropenic patients, a personalized approach for the management of febrile neutropenic patients can be designed by means of an effective antimicrobial stewardship program including the appropriate use of broad-spectrum antibiotics.

Cancer-Associated Microbiota: From Mechanisms of Disease Causation to Microbiota-Centric Anti-Cancer Approaches

Helicobacter pylori infection is the only well-established bacterial cause of cancer. However, due to the integral role of tissue-resident commensals in maintaining tissue-specific immunometabolic homeostasis, accumulated evidence suggests that an imbalance of tissue-resident microbiota that are otherwise considered as commensals, can also promote various types of cancers. Therefore, the present review discusses compelling evidence linking tissue-resident microbiota (especially gut bacteria) with cancer initiation and progression. Experimental evidence supporting the cancer-causing role of gut commensal through the modulation of host-specific processes (e.g., bile acid metabolism, hormonal effects) or by direct DNA damage and toxicity has been discussed. The opportunistic role of commensal through pathoadaptive mutation and overcoming colonization resistance is discussed, and how chronic inflammation triggered by microbiota could be an intermediate in cancer-causing infections has been discussed. Finally, we discuss microbiota-centric strategies, including fecal microbiota transplantation, proven to be beneficial in preventing and treating cancers. Collectively, this review provides a comprehensive understanding of the role of tissue-resident microbiota, their cancer-promoting potentials, and how beneficial bacteria can be used against cancers.

Identification of Prognostic Factors in Patients With Streptococcus Bloodstream Infection

Aim

The purpose of this study was to explore prognostic factors of bloodstream infections (BSIs), a common severe infection and a major cause of mortality worldwide, so as to construct a prognosis model of patients with BSI.

Materials and Methods

Clinical and biochemical test data were obtained retrospectively from the medical records of 562 patients with BSI who had been treated at a single center; the end point was 60 days of all-cause death. The chi-square test was used to compare the mortality of patients grouped by the types of antibiotic treatment. The logistic regression analysis was adopted to identify prognostic factors; the Kaplan–Meier survival curve and log-rank test were conducted to compare the survival rate of patients with different prognostic factors; the receiver operating characteristic (ROC) curve was used to estimate the predictive value of different prognostic factors.

Results

Of the 562 patients, 455 survived (80.96%), and 107 died (19.04%). The mortality rate of patients treated with a combination of antibiotics (25.40%) was higher than that treated with a single antibiotic (15.82%). Univariate analysis identified 19 prognostic factors for patients with BSI, including gender, age, diabetes, malignant tumor (non-blood system), total hospitalization time, alanine aminotransferase, aspartate aminotransferase, total protein, albumin, total bilirubin, direct bilirubin, creatinine, ratio of granulocytes, fibrinogen, D-dimer, platelet, C-reactive protein, shock, and respiratory failure (P < 0.05). Multivariate analysis indicated that albumin (odds ratio [OR] = 0.94, 95% confidence interval [CI]: 0.89–0.99), fibrinogen (OR = 0.61, 95%CI: 0.46–0.82), shock (OR = 16.61, 95%CI: 7.00–39.41), and respiratory failure (OR = 47.53, 95%CI: 19.93–133.64) were independent factors. The combination of four indicators demonstrated a favorable predictive value for the 60-day outcome of patients with BSI, with an area under the ROC of 0.96 (95%CI: 0.94–0.99), sensitivity of 90.65%, specificity of 94.95%, and accuracy of 94.13%.

Conclusions

Shock, respiratory failure, albumin, and fibrinogen are potential independent prognostic factors for 60-day mortality.

Bacterial infections in cancer: A bilateral relationship

Bacteria share a long commensal relationship with the human body. New findings, however, continue to unravel many complexities associated with this old alliance. In the past decades, the dysbiosis of human microbiome has been linked to tumorigenesis, and more recently to spontaneous colonization of existing tumors. The topic, however, remains open for debate as the claims for causative-prevailing dual characteristics of bacteria are mostly based on epidemiological evidence rather than robust mechanistic models. There are also no reviews linking the collective impact of bacteria in tumor microenvironments to the efficacy of cancer drugs, mechanisms of pathogen-initiated cancer and bacterial colonization, personalized nanomedicine, nanotechnology, and antimicrobial resistance. In this review, we provide a holistic overview of the bilateral relationship between cancer and bacteria covering all these aspects. Our collated evidence from the literature does not merely categorize bacteria as cancer causative or prevailing agents, but also critically highlights the gaps in the literature where more detailed studies may be required to reach such a conclusion. Arguments are made in favor of dual drug therapies that can simultaneously co-target bacteria and cancer cells to overcome drug resistance. Also discussed are the opportunities for leveraging the natural colonization and remission power of bacteria for cancer treatment. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Bacterial profile and antimicrobial susceptibility patterns in cancer patients

Background

Bloodstream infections have been the leading complications in cancer patients because they are at high risk for antibiotic-resistant bacterial infections. There is increasing evidence from different parts of the world of the high prevalence of antimicrobial-resistant bacterial strains in cancer patients. The burden of the infection is high in developing countries, especially in Ethiopia. Data on bacterial profile and antimicrobial susceptibility patterns among cancer patients in Ethiopia is limited. Thus, this study aimed to determine the predominant bacterial species causing bacteremia and their antibiotic resistance pattern among cancer patients at University of Gondar comprehensive specialized hospital.

Methods

A hospital-based, cross-sectional study was conducted on 200 study participants from March to July 2021. All cancer patients who developed a fever at the time of hospital visit were included in this study, and their socio-demographic and clinical data were collected using a structured questionnaire. Blood samples (10 mL for adults and 4 mL for children) were collected from each patient, and the collected blood samples were transferred into sterile tryptic soy broth, then incubated at 37°C for 7 days. Tryptic soy broth which showed signs of growth were Gram-stained and sub-cultured on blood agar, chocolate agar, MacConkey agar, and mannitol salt agar. The inoculated plates were then aerobically incubated at 37°C for 18–24 hours and the isolates obtained were identified using standard microbiological methods. Antimicrobial susceptibility tests were done using a modified Kirby-Bauer disk diffusion technique following CLSI 2021 guidelines. Data were entered using EPI data version 4.6 and analyzed with SPSS version 20.

Results

In this study, out of 200 cancer patients included and 67.5% (135/200) of them were males. The majorities of study participants, 56% (113/200) of cancer patients were pediatrics and 26.5% (53/200) of them belong under five years of age. Out of 200 patient samples that had undergone culture, 27% (54/200) samples had bacterial growth. Gram-positive bacterial isolates were predominant, 61.1%, and S. aureus was the predominant Gram-positive isolate, (51.5.6%), followed by coagulase-negative staphylococci (48.5%). Moreover, K. pneumoniae (47%) and P. aeruginosa (29.5%) were the most common Gram-negative bacterial isolates. Among patients who had BSIs, the highest prevalence of BSIs was observed among males (66.7%), and in pediatrics cancer patients (44.2%). Pediatric study participants were more venerable to bloodstream infection (P = 0.000) compared to adult participants. Meropenem (100%), amikacin (100%), piperacillin/tazobactam (72.3%), and ceftazidime (73.5%) were effective against for Gram-negative isolates while cefoxitin (81.2%) and penicillin (70.5%) were effective for Gram-positive isolates. Additionally, most Gram-negative and Gram-positive bacterial isolates were sensitive for gentamycin (75.9%). Multidrug resistance was seen among 17.1% bacterial isolates, and MDR in Gram-negative and Gram-positive bacteria were 83.3% and 16.7%, respectively. Gram-negative bacterial isolates showed a high prevalence of MDR than Gram-positive isolates.

Conclusions and recommendation

BSI’s remains an important health problem in cancer patients, and Gram-positive bacteria were more common as etiologic agents of BSIs in cancer patients. S. aureus was the dominant bacteria followed by CoNS, K. pneumoniae, and P. aeruginosa. Multidrug-resistant isolates found in cancer patients and routine bacterial surveillance and study of their resistance patterns may guide successful antimicrobial therapy and improve the quality of care. Therefore, strict regulation of antibiotic stewardship and infection control programs should be considered in the study area.

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.

A Prospective Randomized Study Comparing Ceftolozane/Tazobactam to Standard of Care in the Management of Neutropenia and Fever in Patients with Hematological Malignancies

Background

With increased use of antibiotics in high risk patients, the investigation of new antibiotics to cover potentially resistant pathogens is warranted. In this prospective randomized trial (NCT03485950), we compared ceftolozane/tazobactam (C/T), a new cephalosporin/β-lactamase inhibitor, to the standard-of-care (SOC) for the empiric treatment of neutropenia and fever in patients with hematological malignancies.

Methods

We enrolled 100 patients to receive intravenous (IV) C/T or SOC antibiotics (cefepime, piperacillin/tazobactam, or meropenem) in combination with gram-positive antibacterial agents. We evaluated responses at the end of IV therapy (EOIV), test of cure (TOC; days 21-28), and late follow-up (LFU; days 35-42).

Results

We analyzed 47 C/T patients and 50 SOC patients. C/T patients had a higher rate of favorable clinical response at EOIV (87% vs 72%). A one-sided non-inferiority analysis indicated that C/T was at least not inferior to the SOC for favorable clinical response at EOIV (p=0.002), TOC (p=0.004) and LFU (p=0.002). Superiority tests showed that C/T led to significantly lower rates of clinical failure at TOC (6% vs 30%; p=0.003) and LFU (9% vs 30%; p=0.008). C/T and SOC patients with documented infections had similar rates of favorable microbiological response. Serious adverse events leading to drug discontinuation (2% vs 0%; p=0.48), and overall mortality (6% vs 4%; p=0.67) were similar in both groups.

Conclusions

The empiric use of C/T in high-risk patients with hematological malignancies and febrile neutropenia is safe and associated with better clinical outcomes than SOC antimicrobial agents.

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.

In vitro activity of imipenem/relebactam and comparator agents against clinical bacterial isolates from patients with cancer

BACKGROUND

Gram-negative bacilli (GNB) are currently the predominant bacterial pathogens in patients with cancer. Many GNB have become problematic due to the widespread emergence of resistance. Imipenem/relebactam (IMP/REL) is a combination of the carbapenem imipenem with relebactam, a non-beta-lactam beta-lactamase inhibitor. It is active against most pathogenic GNB including many that are resistant to other agents. We compared its in vitro activity to 6 other agents against 490 GNB recovered exclusively from patients with cancer, since such data are scarce.

METHODS

CLSI microbroth dilution methods were used for susceptibility testing. Whole genome sequencing (Illumina MiSeq) was performed on 30 selected isolates.

RESULTS

IMP/REL was active against 98 % of Enterobacterales and 87 % of non-Enterobacterales isolates (excluding Stenotrophomonas maltophilia). It had potent activity against ESBL-producing Escherichia coli and Klebsiella pneumoniae, and other Enterobacterales (Enterobacter cloacae, Citrobacter spp., and Serratia spp.), and moderate activity against carbapenem-resistant Enterobacterales. IMI/REL had potent activity against Achromobacter spp., non-MDR Pseudomonas aeruginosa, and Sphingomonas paucimobilis and moderate activity against MDR P. aeruginosa. Overall, imipenem/relebactam was associated with the lowest number of non-susceptible isolates compared to 6 other agents (imipenem, meropenem, cefepime, piperacillin/tazobactam, amikacin, and tigecycline) commonly used in cancer patients. Whole genome sequencing performed on 30 resistant isolates (10 each of E. coli, Klebsiella pneumonia, and P.aeruginosa) did not reveal any predominant mechanism of resistance to imipenem/relebactam.

CONCLUSION

Its in vitro activity indicates that IMI/REL might have a role to play for the treatment of Gram-negative infections in patients with cancer.

Infections in Hospitalized Cancer Patients

Cancer patients are at an increased risk of developing infections that are primarily treatment-driven but may also be malignancy-driven. While cancer treatments such as chemotherapy, radiotherapy, and surgery have been known to improve malignancy morbidity and mortality, they also have the potential to weaken immune defenses and induce periods of severe cytopenia. These adverse effects pave the way for opportunistic infections to complicate a hospitalized cancer patient's clinical course. Understanding the risk each patient inherently has for developing a bacterial, fungal, or viral infection is critical to choosing the correct prophylactic treatment in conjunction with their scheduled cancer therapy. This review discusses the most common types of infections found in hospitalized cancer patients as well as the current guidelines for prophylactic and antimicrobial treatment in cancer patients. In addition, it describes the interaction between antibiotics and cancer therapies for consideration when treating infection in a cancer patient.

C-Reactive Protein Monitoring and Clinical Presentation of Fever as Predictive Factors of Prolonged Febrile Neutropenia and Blood Culture Positivity after Autologous Hematopoietic Stem Cell Transplantation-Single-Center Real-Life Experience

BACKGROUND

Febrile neutropenia (FN) is a medical emergency that requires urgent evaluation, timely administration of empiric broad-spectrum antibiotics and careful monitoring in order to optimize the patient's outcome, especially in the setting of both allogeneic and autologous hematopoietic stem cell transplant (ASCT).

METHODS

In this real-life retrospective study, a total of 49 consecutive episodes of FN were evaluated in 40 adult patients affected by either multiple myeloma (thirty-eight) or lymphoma (eleven), following ASCT, with nine patients having fever in both of the tandem transplantations.

RESULTS

Febrile neutropenia occurred a median of 7 days from ASCT. Median duration of FN was 2 days, with 25% of population that had fever for at least four days. Ten patients had at least one fever spike superior to 39 °C, while the median number of daily fever spikes was two. Twenty patients had positive blood cultures with XDR germs, namely Pseudomonas aeruginosa and Klebsiella pneumoniae, present in seven cases. ROC analysis of peak C-reactive protein (CRP) values was conducted based on blood culture positivity and a value of 12 mg/dL resulted significant. Onset of prolonged fever with a duration greater than 3 days was associated with the presence of both a peak number of three or more daily fever spikes (p = 0.02) and a body temperature greater than 39 °C (p = 0.04) based on odds ratio (OR). Blood culture positivity and peak CRP values greater than 12 mg/dL were also associated with prolonged fever duration, p = 0.04, and p = 0.03, respectively. The probability of blood culture positivity was also greater in association with fever greater than 39 °C (p = 0.04). Furthermore, peak CRP values below the cut-off showed less probability of positive blood culture (p = 0.02).

CONCLUSIONS

In our study, clinical characteristics of fever along with peak CRP levels were associated with a higher probability of both prolonged fever duration and positive blood culture, needing extended antibiotic therapy.

Comparison between hospital- and community-acquired septic shock in children: a single-center retrospective cohort study

BACKGROUND

We explored the differences in baseline characteristics, pathogens, complications, outcomes, and risk factors between children with hospital-acquired septic shock (HASS) and community-acquired septic shock (CASS) in the pediatric intensive care unit (PICU).

METHODS

This retrospective study enrolled children with septic shock at the PICU of Beijing Children's Hospital from January 1, 2016, to December 31, 2019. The patients were followed up until 28 days after shock or death and were divided into the HASS and CASS group. Logistic regression analysis was used to identify risk factors for mortality.

RESULTS

A total of 298 children were enrolled. Among them, 65.9% (n = 91) of HASS patients had hematologic/oncologic diseases, mainly with Gram-negative bacterial bloodstream infections (47.3%). Additionally, 67.7% (n = 207) of CASS patients had no obvious underlying disease, and most experienced Gram-positive bacterial infections (30.9%) of the respiratory or central nervous system. The 28-day mortality was 62.6% and 32.7% in the HASS and CASS groups, respectively (P < 0.001). Platelet [odds ratio (OR) = 0.996, 95% confidence interval (CI) = 0.992-1.000, P = 0.028], positive pathogen detection (OR = 3.557, 95% CI = 1.307-9.684, P = 0.013), and multiple organ dysfunction syndrome (OR = 10.953, 95% CI = 1.974-60.775, P = 0.006) were risk factors for 28-day mortality in HASS patients. Lactate (OR = 1.104, 95% CI = 1.022-1.192, P = 0.012) and mechanical ventilation (OR = 8.114, 95% CI = 1.806-36.465, P = 0.006) were risk factors for 28-day mortality in patients with CASS.

CONCLUSIONS

The underlying diseases, pathogens, complications, prognosis, and mortality rates varied widely between the HASS and CASS groups. The predictors of 28-day mortality were different between HASS and CASS pediatric patients with septic shock.

Update on Febrile Neutropenia in Pediatric Oncological Patients Undergoing Chemotherapy

Febrile neutropenia (FN) is a common complication of chemotherapy in oncological children and one of the most important causes of morbidity and mortality in these patients. The early detection of a bacteremia and the rapid therapeutic intervention are crucial to improve the outcome. We analyzed the literature in order to clarify the epidemiology of FN in children undergoing chemotherapy, the specific factors associated with a negative outcome, the most common etiology, and the value of biological markers as a tool to make an early diagnosis or to monitor the evolution of the infection. Several studies have tried to identify specific factors that could help the clinician in the detection of an infection and in its microbiological identification. However, due to the heterogenicity of the available studies, sufficient evidence is lacking to establish the role of these risk factors in clinical practice and future research on this topic appear mandatory. Determinations of risk factors, etiology, and markers of febrile episodes in these patients are complicated by the characteristics of the underlying illness and the effects of treatments received. Although some studies have tried to develop an evidence-based guideline for the empiric management of FN in pediatrics, validated predictive scores and algorithms are still lacking and urgently needed.

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.

Antibiotic resistance in the patient with cancer: Escalating challenges and paths forward

Infection is the second leading cause of death in patients with cancer. Loss of efficacy in antibiotics due to antibiotic resistance in bacteria is an urgent threat against the continuing success of cancer therapy. In this review, the authors focus on recent updates on the impact of antibiotic resistance in the cancer setting, particularly on the ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.). This review highlights the health and financial impact of antibiotic resistance in patients with cancer. Furthermore, the authors recommend measures to control the emergence of antibiotic resistance, highlighting the risk factors associated with cancer care. A lack of data in the etiology of infections, specifically in oncology patients in United States, is identified as a concern, and the authors advocate for a centralized and specialized surveillance system for patients with cancer to predict and prevent the emergence of antibiotic resistance. Finding better ways to predict, prevent, and treat antibiotic-resistant infections will have a major positive impact on the care of those with cancer.

Modelling and Simulation of the Effect of Targeted Decolonisation on Incidence of Extended-Spectrum Beta-Lactamase-Producing Enterobacterales Bloodstream Infections in Haematological Patients

Introduction

Haematological patients are at higher risk of bloodstream infections (BSI) after chemotherapy. The aim of this study was to develop a simulation model assessing the impact of selective digestive decontamination (SDD) of haematological patients colonised with extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E) on the incidence of ESBL-E BSI after chemotherapy.

Methods

A patient population was created by a stochastic simulation model mimicking the patients’ states of colonisation with ESBL-E during hospitalisation. A systematic literature search was performed to inform the model. All ESBL-E carriers were randomised (1:1) to either the intervention (targeted SDD) or the control group (placebo). ESBL-E BSI incidence was the outcome of the model. Sensitivity analyses were performed by prevalence of ESBL-E carriage at hospital admission (low: < 10%, medium: 10–25%, high: > 25%), duration of neutropenia after receiving chemotherapy, administration of antibiotic prophylaxis with quinolones, and time interval between SDD and chemotherapy.

Results

The model estimated that the administration of targeted SDD before chemotherapy reduces the incidence of ESBL-E BSI in the hospitalised haematological population up to 27%. The greatest benefit was estimated in high-prevalence settings, regardless of the duration of neutropenia, the time interval before chemotherapy, and the administration of antibiotic prophylaxis with quinolones (p < 0.05). In medium-prevalence settings, SDD was effective in patients receiving quinolone prophylaxis, with either 1-day time interval before chemotherapy and a neutropenia duration > 6 days (p < 0.05) or 7-day time interval before chemotherapy and a neutropenia duration > 9 days (p < 0.05). No benefit was observed in low-prevalence settings.

Conclusions

Our model suggests that targeted SDD could decrease the rate of ESBL-E BSI in haematological carriers before chemotherapy in the setting of high ESBL-E prevalence at hospital admission. These estimates require confirmation by well-designed multicentre RCTs, including the assessment of the impact on resistance/disruption patterns of gut microbiome.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-021-00550-3.

Administration of a β-lactam Prior to Vancomycin as the First Dose of Antibiotic Therapy Improves Survival in Patients with Bloodstream Infections

OBJECTIVE

Prompt initiation of antibiotic therapy improves the survival of patients with bloodstream infections (BSI). We sought to determine if the sequence of administration of the first dose of antibiotic therapy (i.e., β-lactam or vancomycin, if both cannot be administered simultaneously) impacts early mortality for patients with BSI.

METHODS

We conducted a multicenter, observational study of patients ≥13 years with BSIs to evaluate the association of the sequence of antibiotic administration with 7-day mortality using inverse probability of treatment weighting (IPTW) incorporating propensity scores. Propensity scores were generated based on: demographics, Pitt bacteremia score, ICU status, highest lactate, highest WBC count, Charlson Comorbidity index, severe immunocompromise, administration of active empiric therapy, combination therapy, and time from emergency department arrival to first antibiotic dose.

RESULTS

Of 3,376 eligible patients, 2,685 (79.5%) received a β-lactam and 691 (20.5%) received vancomycin as their initial antibiotic. In the IPTW cohort, exposed and unexposed patients were similar on all baseline variables. Administration of a β-lactam agent prior to vancomycin protected against 7-day mortality (aOR 0.48 (95% CI: 0.33-0.69)]. Similar results were observed when evaluating 48-hour mortality (aOR 0.45 [95% CI: 0.24-0.83]). Administration of vancomycin prior to a β-lactam was not associated with improved survival in the subgroup of 524 patients with methicillin-resistant Staphylococcus aureus BSI (aOR 0.93 [95% CI: 0.33-2.63]).

CONCLUSIONS

For ill-appearing patients likely to be experiencing a BSI, prioritizing administration of a β-lactam over vancomycin may reduce early mortality, underscoring the significant impact of a relatively simple practice change on improving patient survival.

Clinical prediction of bacteremia and early antibiotics therapy in patients with solid tumors

OBJECTIVE

To investigate the relationship between the systemic inflammatory response syndrome (SIRS), early antibiotic use, and bacteremia in solid-tumor patients.

DESIGN, SETTING, AND PARTICIPANTS

We conducted a retrospective observational study of adults with solid tumors admitted to a tertiary-care hospital through the emergency department over a 2-year period. Patients with neutropenic fever, organ transplant, trauma, or cardiopulmonary arrest were excluded.

METHODS

Rates of SIRS, bacteremia, and early antibiotics (initiation within 8 hours of presentation) were compared using the χ2 and Student t tests. Binomial regression and receiver operator curves were analyzed to assess predictors of bacteremia and early antibiotics.

RESULTS

Early antibiotics were administered in 507 (37%) of 1,344 SIRS-positive cases and 492 (22%) of 2,236 SIRS-negative cases (P < .0001). Of SIRS-positive cases, 70% had blood cultures drawn within 48 hours and 19% were positive; among SIRS negative cases, 35% had cultures and 13% were positive (19% vs 13%; P = .003). Bacteremic cases were more often SIRS positive than nonbacteremic cases (60% vs 50%; P =.003), but they received early antibiotics at similar rates (50% vs 49%, P = .72). Three SIRS components predicted early antibiotics: temperature (OR, 1.7; 95% CI, 1.31-2.29; P = .0001), tachycardia (OR, 1.4; 95% CI, 1.10-1.69; P < .0001), and white blood-cell count (OR, 1.8; 95% CI, 1.56-2.14; P < .0001). Only temperature (OR, 1.6; 95% CI, 1.09-2.41; P = .01) and tachycardia (OR, 1.5; 95% CI, 1.09-2.06; P = .01) predicted bacteremia. SIRS criteria as a composite were poorly predictive of bacteremia (AUC, 0.57).

CONCLUSIONS

SIRS criteria are frequently used to determine the need for early antibiotics, but they are poor predictors of bacteremia in solid-tumor patients. More reliable models are needed to guide judicious use of antibiotics in this population.

Hospital-Acquired Blood Stream Infection in an Adult Intensive Care Unit

Background

Hospital-acquired blood stream infections are a common and serious complication in critically ill patients.

Methods

A retrospective case series was undertaken investigating the incidence and causes of bacteraemia in an adult intensive care unit with a high proportion of postoperative cardiothoracic surgical and oncology patients.

Results

405 eligible patients were admitted to the intensive care unit over the course of nine months. 12 of these patients developed a unit-acquired blood stream infection. The average Acute Physiology And Chronic Health Evaluation II (APACHE II) score of patients who developed bacteraemia was greater than that of those who did not (19.8 versus 16.8, respectively). The risk of developing bacteraemia was associated with intubation and higher rates of invasive procedures. The mortality rate amongst the group of patients that developed bacteraemia was 33%; this is in contrast to the mortality rate in our unit as 27.2%. There was a higher proportion of Gram-negative bacteria isolated on blood cultures (9 out of 13 isolates) than in intensive care units reported in other studies.

Conclusion

Critical-care patients are at risk of secondary bloodstream infection. This study highlights the importance of measures to reduce the risk of infection in the intensive-care setting, particularly in patients who have undergone invasive procedures.