Bloodstream infections in patients with solid tumors: epidemiology, antibiotic therapy, and outcomes in 528 episodes in a single cancer center

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.

Port implantation-related bloodstream infection caused by Wickerhamomyces myanmarensis: A case report

Background and Purpose

Wickerhamomyces myanmarensis is a new opportunistic yeast previously named Pichai myanmarensis, which belongs to the order Saccharomycetales. Since its discovery, one environmental isolate of W. myanmarensis has been reported from Myanmar, and one clinical sample from Iran.

Case Report

We report a case of bloodstream infection related to an implantable venous access port. W. myanmarensis was isolated from patient's blood after chemotherapy, which was meant to control and heal T-cell lymphoblastic lymphoma. Broth dilution minimum inhibitory concentrations were performed according to the CLSI M27-A3 document. The patient recovered with intravenous voriconazole and was discharged with the recommended prescription of oral voriconazole as a maintenance drug.

Conclusion

So far, only one case of W. myanmarensis fungemia has been reported in the world in 2019. This is the second case of bloodstream infection with this yeast from a patient undergoing chemotherapy in Iran.

Mortality in pediatric oncology and stem cell transplant patients with bloodstream infections

Background

Bloodstream infections (BSI) continue to represent a significant source of morbidity for pediatric oncology patients, however less is known regarding this population's risk of death. We sought to evaluate the risk of BSI and death at a large pediatric cancer center.

Methods

We retrospectively collected inpatient data from pediatric oncology and hematopoietic stem cell transplant (HSCT) patients over a 9-year period. We performed univariate and multivariable modeling to assess risk of BSI and mortality examining the following variables: demographics, underlying malignancy, history of HSCT, central line type, and febrile neutropenia (FN).

Results

During the study period, 6763 admissions from 952 patients met inclusion criteria. BSI occurred in 367 admissions (5.4%) from 231 unique individuals. Risk factors for BSI include younger age, diagnoses of hemophagocytic lymphohistiocytosis or acute myeloid leukemia, ethnicity, and history of HSCT. Mortality for those with BSI was 6.5%, compared to 0.7% without (OR 7.2, CI 4.1 - 12.7, p<0.0001). In patients with BSI, admissions with FN were associated with reduced mortality compared to admissions without FN (OR 0.21, CI 0.05 - 0.94, p=0.04). In both univariate and multivariable analysis, no other risk factor was significantly associated with mortality in patients with BSI.

Conclusion

BSI is a significant source of mortality in pediatric oncology and HSCT patients. While demographic variables contribute to the risk of BSI, they did not influence mortality. These findings highlight the importance of BSI prevention to reduce the risk of death in pediatric oncology patients. Future studies should focus on comprehensive BSI prevention.

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.

Comparative Genomics of Streptococcus oralis Identifies Large Scale Homologous Recombination and a Genetic Variant Associated with Infection

The viridans group streptococci (VGS) are a large consortium of commensal streptococci that colonize the human body. Many species within this group are opportunistic pathogens causing bacteremia and infective endocarditis (IE), yet little is known about why some strains cause invasive disease. Identification of virulence determinants is complicated by the difficulty of distinguishing between the closely related species of this group. Here, we analyzed genomic data from VGS that were isolated from blood cultures in patients with invasive infections and oral swabs of healthy volunteers and then determined the best-performing methods for species identification. Using whole-genome sequence data, we characterized the population structure of a diverse sample of Streptococcus oralis isolates and found evidence of frequent recombination. We used multiple genome-wide association study tools to identify candidate determinants of invasiveness. These tools gave consistent results, leading to the discovery of a single synonymous single nucleotide polymorphism (SNP) that was significantly associated with invasiveness. This SNP was within a previously undescribed gene that was conserved across the majority of VGS species. Using the growth in the presence of human serum and a simulated infective endocarditis vegetation model, we were unable to identify a phenotype for the enriched allele in laboratory assays, suggesting a phenotype may be specific to natural infection. These data highlighted the power of analyzing natural populations for gaining insight into pathogenicity, particularly for organisms with complex population structures like the VGS. IMPORTANCE The viridians group streptococci (VGS) are a large collection of closely related commensal streptococci, with many being opportunistic pathogens causing invasive diseases, such as bacteremia and infective endocarditis. Little is known about virulence determinants in these species, and there is a distinct lack of genomic information available for the VGS. In this study, we collected VGS isolates from invasive infections and healthy volunteers and performed whole-genome sequencing for a suite of downstream analyses. We focused on a diverse sample of Streptococcus oralis genomes and identified high rates of recombination in the population as well as a single genome variant highly enriched in invasive isolates. The variant lies within a previously uncharacterized gene, nrdM, which shared homology with the anaerobic ribonucleoside triphosphate reductase, nrdD, and was highly conserved among VGS. This work increased our knowledge of VGS genomics and indicated that differences in virulence potential among S. oralis isolates were, at least in part, genetically determined.

Effect of antiplatelet agents on Escherichia coli sepsis mechanisms: A review

Despite ever-increasing improvements in the prognosis of sepsis, this condition remains a frequent cause of hospitalization and mortality in Western countries. Sepsis exposes the patient to multiple complications, including thrombotic complications, due to the ability of circulating bacteria to activate platelets. One of the bacteria most frequently implicated in sepsis, Escherichia coli, a Gram-negative bacillus, has been described as being capable of inducing platelet activation during sepsis. However, to date, the mechanisms involved in this activation have not been clearly established, due to their multiple characteristics. Many signaling pathways are thought to be involved. At the same time, reports on the use of antiplatelet agents in sepsis to reduce platelet activation have been published, with variable results. To date, their use in sepsis remains controversial. The aim of this review is to summarize the currently available knowledge on the mechanisms of platelet activation secondary to Escherichia coli sepsis, as well as to provide an update on the effects of antiplatelet agents in these pathological circumstances.

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.

Effects of Inappropriate Administration of Empirical Antibiotics on Mortality in Adults With Bacteraemia: Systematic Review and Meta-Analysis

Introduction

Bloodstream infections are associated with high mortality rates and contribute substantially to healthcare costs, but a consensus on the prognostic benefits of appropriate empirical antimicrobial therapy (EAT) for bacteraemia is lacking.

Methods

We performed a systematic search of the PubMed, Cochrane Library, and Embase databases through July 2021. Studies comparing the mortality rates of patients receiving appropriate and inappropriate EAT were considered eligible. The quality of the included studies was assessed using Joanna Briggs Institute checklists.

Results

We ultimately assessed 198 studies of 89,962 total patients. The pooled odds ratio (OR) for the prognostic impacts of inappropriate EAT was 2.06 (P < 0.001), and the funnel plot was symmetrically distributed. Among subgroups without between-study heterogeneity (I² = 0%), those of patients with severe sepsis and septic shock (OR, 2.14), Pitt bacteraemia scores of ≥4 (OR, 1.88), cirrhosis (OR, 2.56), older age (OR, 1.78), and community-onset/acquired Enterobacteriaceae bacteraemia infection (OR, 2.53) indicated a significant effect of inappropriate EAT on mortality. The pooled adjusted OR of 125 studies using multivariable analyses for the effects of inappropriate EAT on mortality was 2.02 (P < 0.001), and the subgroups with low heterogeneity (I² < 25%) exhibiting significant effects of inappropriate EAT were those of patients with vascular catheter infections (adjusted OR, 2.40), pneumonia (adjusted OR, 2.72), or Enterobacteriaceae bacteraemia (adjusted OR, 4.35). Notably, the pooled univariable and multivariable analyses were consistent in revealing the negligible impacts of inappropriate EAT on the subgroups of patients with urinary tract infections and Enterobacter bacteraemia.

Conclusion

Although the current evidence is insufficient to demonstrate the benefits of prompt EAT in specific bacteraemic populations, we indicated that inappropriate EAT is associated with unfavorable mortality outcomes overall and in numerous subgroups. Prospective studies designed to test these specific populations are needed to ensure reliable conclusions.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42021270274.

Pseudomonas aeruginosa Infections in Cancer Patients

Pseudomonas aeruginosa (P. aeruginosa) is one of the most frequent opportunistic microorganisms causing infections in oncological patients, especially those with neutropenia. Through its ability to adapt to difficult environmental conditions and high intrinsic resistance to antibiotics, it successfully adapts and survives in the hospital environment, causing sporadic infections and outbreaks. It produces a variety of virulence factors that damage host cells, evade host immune responses, and permit colonization and infections of hospitalized patients, who usually develop blood stream, respiratory, urinary tract and skin infections. The wide intrinsic and the increasing acquired resistance of P. aeruginosa to antibiotics make the treatment of infections caused by this microorganism a growing challenge. Although novel antibiotics expand the arsenal of antipseudomonal drugs, they do not show activity against all strains, e.g., MBL (metalo-β-lactamase) producers. Moreover, resistance to novel antibiotics has already emerged. Consequently, preventive methods such as limiting the transmission of resistant strains, active surveillance screening for MDR (multidrug-resistant) strains colonization, microbiological diagnostics, antimicrobial stewardship and antibiotic prophylaxis are of particular importance in cancer patients. Unfortunately, surveillance screening in the case of P. aeruginosa is not highly effective, and a fluoroquinolone prophylaxis in the era of increasing resistance to antibiotics is controversial.

Microbial spectrum and drug resistance profile in solid malignancies in a large tertiary hospital from Palestine

BACKGROUND

Since the available data for bloodstream infections in solid malignancy tumors are somewhat limited in Palestine, prevention of infection before the occurrence, controlling it when it occurs, and implementing stewardship programs are important ways in the whole therapy of solid tumor patients, which is becoming challenging recently with the evolution of more antimicrobial drug-resistant pathogens. Therefore, our study aims to assess the microbial spectrum and antimicrobial sensitivity and the overall outcome related to many clinical risk factors in patients with solid tumor patients seeking care in a referral hospital as an experience from a developing country.

METHODS

From the onset of 2018 to the end of 2020, a total of 116 episodes with positive blood cultures were retrospectively studied and analyzed in 96 patients who had solid tumors in a referral hospital in Palestine.

RESULTS

We identified 116 positive blood cultures in 96 patients with a male to female ratio of 1:1. The mean age was 58 years. Breast cancer was the tumor most frequently recorded (13.5%), followed by urinary tract tumors (10.4%). The most common source of episodes with positive blood culture was catheter-related. Gram-positive bacteria accounted for 52.6% of blood cultures with the predomination of Staphylococcus species. On the contrary, Gram-negative bacteria were documented in 39.7% of the cultures, with E. coli being the most frequent bacteria. Regarding fungi that were only Candida species, it was isolated in 15.5% of the cultures.28.4% of patients started on a single antimicrobial as an initial regimen, the remaining started combination antimicrobial therapy. The initial antimicrobials used most frequently were aminoglycosides in 29.3% of the episodes. All species of Staphylococcus were sensitive to vancomycin. Enterococcus species were fully resistant to ciprofloxacin. In the case of E. coli, the isolates were 100% sensitive to imipenem, meropenem, and amikacin and were mostly resistant to ampicillin, where the sensitivity was only about 19.5%. P.aeruginosa was sensitive in 83.3% of cultures to both piperacillin-tazobactam and gentamicin, but highly resistant to imipenem, in which sensitivity decreased to 50%. The isolates of Klebsiella species were 72.2% sensitive to gentamicin, meropenem, and imipenem and 100% resistant to ampicillin. A. baumannii was 50% sensitive to trimethoprim-sulfamethoxazole. Candida species showed high sensitivity to both caspofungin and flucytosine (83.3%), followed by 77.8% sensitivity to voriconazole. Death was reported in 27.6% of the episodes and there was a significant relationship between shock at presentation and death (p = 0.010).

CONCLUSIONS

The findings of this investigation confirm the prevalent BSI seen in patients with solid malignancies and demonstrate a significant percentage of antibiotic resistance. Therefore, stewardship programs that dig deep before using any type of antimicrobials will help reduce the risk of resistance to antibiotics. In addition, the implementation of infection control surveillance plays an important role in decreasing the risk of contamination.

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.

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.

Intrauterine infection and postpartum bacteremia due to Streptococcus gallolyticus subsp gallolyticus: An emerging concern

Streptococcus gallolyticus is a gram-positive coccus belonging to the family Streptococcus bovis/Streptococcus equinus complex (SBSEC). Most cases of SBSEC bacteremia are reported in elderly males with underlying hepatobiliary disease and associated with infective endocarditis (IE) or colonic malignancy. The gastrointestinal tract is the most common portal of entry, followed by the urinary tract and hepatobiliary tree. We present 5 cases of intrapartum bacteremia caused by S. gallolyticus subsp gallolyticus reported from the labor unit of our hospital from 2019 to 2021. There was histopathological or microbiological evidence of chorioamnionitis in each case. All the mothers were below the age of 35 years, and none of them had underlying hepatobiliary or colonic disease. All maternal antenatal screenings for group B streptococci (GBS) were negative. All the isolates were susceptible to penicillins, ceftriaxone, carbapenems, and vancomycin. Three of them were treated with ceftriaxone and two with aminopenicillins. Duration of treatment varied from 8 days to 14 days. None of the babies were low birth weight or pre-term. All but one baby had clinical sepsis requiring neonatal intensive care unit (NICU) stay, with one having evidence of meningitis and three respiratory distress syndromes (RDS). None of the babies had S. gallolyticus bacteremia. All mothers and babies made a complete recovery without any complications. These cases suggest that S. gallolyticus subsp gallolyticus can be a rare but emerging cause of intrauterine infection complicated by post-partum bacteremia. There is possibility of colonization of maternal genital tract with S. gallolyticus causing neonatal infection.

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.

Antibacterial Activity of T22, a Specific Peptidic Ligand of the Tumoral Marker CXCR4

CXCR4 is a cytokine receptor used by HIV during cell attachment and infection. Overexpressed in the cancer stem cells of more than 20 human neoplasias, CXCR4 is a convenient antitumoral drug target. T22 is a polyphemusin-derived peptide and an effective CXCR4 ligand. Its highly selective CXCR4 binding can be exploited as an agent for the cell-targeted delivery and internalization of associated antitumor drugs. Sharing chemical and structural traits with antimicrobial peptides (AMPs), the capability of T22 as an antibacterial agent remains unexplored. Here, we have detected T22-associated antimicrobial activity and biofilm formation inhibition over Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa, in a spectrum broader than the reference AMP GWH1. In contrast to GWH1, T22 shows neither cytotoxicity over mammalian cells nor hemolytic activity and is active when displayed on protein-only nanoparticles through genetic fusion. Under the pushing need for novel antimicrobial agents, the discovery of T22 as an AMP is particularly appealing, not only as its mere addition to the expanding catalogue of antibacterial drugs. The recognized clinical uses of T22 might allow its combined and multivalent application in complex clinical conditions, such as colorectal cancer, that might benefit from the synchronous destruction of cancer stem cells and local bacterial biofilms.

Clinical characteristics, aetiology and mortality/recurrence risk factors of acute cholangitis in patients with and without biliary stent

OBJECTIVES

Acute cholangitis is one of the most frequent complications in patients carrying biliary stents. The aim of our study is to analyze the demographic and clinical characteristics, as well as the microbiological profile and evolution of patients with acute bacteremic cholangitis, comparing them based upon they were or not biliary stent carriers.

METHODS

We performed a retrospective analysis of all consecutive patients over 18 years-old with a stent placement in our center between 2008 and 2017 were included. We compared them with our prospective cohort of patients with a diagnosis of acute bacteremic cholangitis. Primary outcome was 30-day mortality. Secondary outcome was clinical cure at day 7, 14-day mortality and 90-day recurrence.

RESULTS

Two hundred and seventy-three patients were analyzed, including 156 in the stent-related (SR) and 117 in the stent not-related (SNR) group, respectively. Stent-related colangitis patients were younger, with more comorbidities and with a greater severity of infection. Escherichia coli and Klebsiella pneumonia were the most frequent isolation. Enterococcus spp. was the third most frequent isolation in SR group but were uncommon in SNR patients; where E. coli was the most prevalent microorganism. Septic shock (HR 3.44, 95% [CI 1.18-8.77]), inadequate empirical treatment (HR 2.65, 95% CI [1.38-.7.98]) and advanced neoplasia (HR 2.41, 95% CI [1.55-6.44]) were independent 30-day mortality risk factors. The 90-day recurrence rate significantly higher in those patients with stent-related cholangitis (29% vs. 13%, p=0.016) and stent replacement was associated with lower recurrence rate (HR 0.38, 95% CI [0.11-0.77]).

CONCLUSIONS

Clinical and microbiological profile, as well as outcome of patients with SR and SNR cholangitis were different. In SR group, recurrence rate was high and stent replacement was associated with a lower risk.

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.

Risk Factors of Death in Bloodstream Infections Caused by AmpC β-Lactamase-Producing Enterobacterales in Patients with Neoplasia

Purpose

The infections caused by ESCPM Enterobacterales (Enterobacter spp., Serratia spp., Citrobacter spp., Providencia spp. and Morganella spp.) have limited therapeutic options. Patients with neoplastic diseases are particularly vulnerable to bloodstream infections (BSIs).

Objective

To analyze determinant factors of death in patients with neoplasia complicated with BSI caused by ESCPM Enterobacterales.

Patients and Methods

A cohort study of patients aged 18 years or older with neoplasia and BSI due to ESCPM group was conducted at the Cancer Hospital I of the National Cancer Institute, Brazil, from September 2012 to December 2017. The variables associated with death were analyzed using multivariate logistic regression.

Results

Of the 103 patients included in the cohort, 67.0% were male, the median age was 63 years and 67.0% had solid tumors. Of the 107 BSI episodes evaluated, 70.1% were hospital-acquired infections, 54.2% were secondary to extravascular focus of infection, gastrointestinal tract (19.6%), mainly. Enterobacter spp. (n: 49, 45.4%) was the most frequent agent isolated followed by Serratia spp. (n: 34, 31.5%), Morganella morganii (n: 16, 14.9%), Citrobacter freundii. (n: 7, 6.5%) and Providencia spp. (n: 2, 1.8%). Ten (9.3%) BSI episodes were caused by multidrug-resistant ESCPM Enterobacterales (MDR-ESCPM). The 7-day and 30-day mortality were 9.3% and 21.5%, respectively. The BSIs caused by MDR-ESCPM were independently associated with 7-day death (OR = 21.62 95% CI: 1.81–258.51 P = 0.01). Monotherapy with piperacillin-tazobactam tended to be associated with 7-day death (OR = 10.46 95% CI: 0.97–112.91 P = 0.05) and 30-day death (OR = 2.73 95% CI: 0.96–7.70 P = 0.05).

Conclusion

BSIs due to ESCPM group have high mortality and when caused by MDR-ESCPM are independently associated with 7-day death. The possible association of piperacillin-tazobactam monotherapy for BSI-ESCPM with death needs to be better studied.

Bacteremia in critically ill immunocompromised patients with acute hypoxic respiratory failure: A post-hoc analysis of a prospective multicenter multinational cohort

PURPOSE

The characteristics and impact of bacteremia have not been widely investigated in immunocompromised patients with acute respiratory failure (ARF).

METHODS

We performed a secondary analysis of a prospective cohort of immunocompromised patients with ARF (EFRAIM study). After exclusion of blood cultures positive for coagulase negative Staphylococci, we compared patients with (n = 236) and without (n = 1127) bacteremia.

RESULTS

The incidence of bacteremia was 17%. Bacterial pneumonia and extra-pulmonary ARDS were the main causes of ARF in bacteremic patients. Bacteremia involved gram negative rods (48%), gram positive cocci (40%) or were polymicrobial (10%). Bacteremic patients had more hematological malignancy, higher SOFA scores and increased organ support within 7 days. Bacteremia was associated with higher crude ICU mortality (40% versus 32%, p = 0.02), but neither hospital (49% versus 44%, p = 0.17) nor 90-day mortality (60% versus 56%, p = 0.25) were different from non-bacteremic patients. After propensity score matching based on baseline characteristics, the difference in ICU mortality lost statistical significance (p = 0.06), including in a sensitivity analysis restricted to patients with pneumonia.

CONCLUSIONS

We analyzed a large population of immunocompromised patients with ARF and an incidence of bacteremia of 17%. We could not demonstrate an impact of bacteremia on mortality after adjusting for baseline characteristics.

Fluoroquinolone treatment as a protective factor for 10-day mortality in Streptococcus pneumoniae bacteremia in cancer patients

To evaluate the prognostic factors in adult cancer patients with pneumococcal bacteremia, describe episode features and the phenotypic characteristics of the isolated strains. We evaluated the episodes in patients admitted to a cancer hospital between 2009 and 2015. The outcomes were defined as 48 h mortality and mortality within 10 days after the episode. The variables evaluated were: age, sex, ethnicity, ECOG, Karnofsky score, SOFA, cancer type, metastasis, chemotherapy, radiotherapy, neutropenia, previous antibiotic therapy, community or healthcare-acquired infection, comorbidities, smoking, pneumococcal vaccination, infection site, presence of fever, polymicrobial infection, antimicrobial susceptibility, serotype and treatment. 165 episodes were detected in 161 patients. The mean age was 61.3 years; solid tumors were the most prevalent (75%). 48 h and 10-day mortality were 21% (34/161) and 43% (70/161) respectively. The 48 h mortality- associated risk factors were SOFA and polymicrobial bacteremia; 10-day mortality-associated risk factors were fever, neutropenia, ECOG 3/4, SOFA and fluoroquinolones as a protective factor. Pneumococcal bacteremia presented high mortality in cancer patients, with prognosis related to intrinsic host factors and infection episodes features. Fluoroquinolone treatment, a protective factor in 10-day mortality, has potential use for IPDs and severe community-acquired pneumonia in cancer patients.

Prevalence, predictors, and mortality of bloodstream infections due to methicillin-resistant Staphylococcus aureus in patients with malignancy: systemic review and meta-analysis

BACKGROUND

Cancer patients are more likely to develop and die of bloodstream infection (BSI) than noncancer patients. Methicillin-resistant Staphylococcus aureus (MRSA), which is associated with immense mortality and economic burden worldwide, is not covered by the recommended initial antibiotic therapy for cancer patients with BSI. This systemic review was performed to estimate the global methicillin-resistant Staphylococcus aureus (MRSA) prevalence among bacteremia in patients with malignancy, and further study the predictors and mortality of cancer patients with MRSA bacteremia.

METHODS

The PubMed and EMBASE databases were searched for studies published from Jan. 2000 to Mar. 2020 that provided primary data on the prevalence, predictors, or mortality of MRSA bacteremia in cancer patients. A random-effects model meta-analysis was performed to estimate the pooled prevalence of MRSA with 95% confidence intervals (95% CIs).

RESULTS

The pooled prevalence of MRSA was 3% (95% CI 2-5%) among all bloodstream infections (BSIs) and 44% (95% CI 32-57%) among S. aureus bacteremia in cancer patients. Based on geographical stratification, the pooled prevalence was 5% in Africa (95% CI 1-14%), 1% in Americas (95% CI 1-2%), 2% in Europe (95% CI 1-4%), 4% in Western Pacific (95% CI 2-7%), 8% in South-east Asia (95% CI 4-14%) and 0% in Eastern Mediterranean (95% CI 0-3%). No significant temporal change in MRSA rates was detected in this analysis (R2 = 0.06; P = 0.24). Predictors for MRSA BSIs among cancer patients were identified by comparison with their methicillin-susceptible counterparts, and they were mainly related to healthcare-associated infections and immunosuppression. Finally, the 60-day mortality in adult cancer patients with MRSA BSIs was reported to be 12%, and the 6-month overall mortality was 43.2%, with community-onset infection, secondary BSI, and vancomycin MIC≥2 g/mL being the risk factors for mortality.

CONCLUSIONS

Although the prevalence of MRSA BSIs among cancer patients is relatively low, it did not decline over time as MRSA BSIs in the general hospital population and the high mortality rate was related to MRSA BSIs in patients with malignancy.

Colonization with multi-drug-resistant organisms negatively impacts survival in patients with non-small cell lung cancer

Objectives

Multidrug-resistant organisms (MDRO) are considered an emerging threat worldwide. Data covering the clinical impact of MDRO colonization in patients with solid malignancies, however, is widely missing. We sought to determine the impact of MDRO colonization in patients who have been diagnosed with Non-small cell lung cancer (NSCLC) who are at known high-risk for invasive infections.

Materials and methods

Patients who were screened for MDRO colonization within a 90-day period after NSCLC diagnosis of all stages were included in this single-center retrospective study.

Results

Two hundred and ninety-five patients were included of whom 24 patients (8.1%) were screened positive for MDRO colonization (MDRO^pos) at first diagnosis. Enterobacterales were by far the most frequent MDRO detected with a proportion of 79.2% (19/24). MDRO colonization was present across all disease stages and more present in patients with concomitant diabetes mellitus. Median overall survival was significantly inferior in the MDRO^pos study group with a median OS of 7.8 months (95% CI, 0.0–19.9 months) compared to a median OS of 23.9 months (95% CI, 17.6–30.1 months) in the MDRO^neg group in univariate (p = 0.036) and multivariate analysis (P = 0.02). Exploratory analyses suggest a higher rate of non-cancer-related-mortality in MDRO^pos patients compared to MDRO^neg patients (p = 0.002) with an increased rate of fatal infections in MDRO^pos patients (p = 0.0002).

Conclusions

MDRO colonization is an independent risk factor for inferior OS in patients diagnosed with NSCLC due to a higher rate of fatal infections. Empirical antibiotic treatment approaches should cover formerly detected MDR commensals in cases of (suspected) invasive infections.

Clinical characteristics, aetiology and mortality/recurrence risk factors of acute cholangitis in patients with and without biliary stent

OBJECTIVES

Acute cholangitis is one of the most frequent complications in patients carrying biliary stents. The aim of our study is to analyze the demographic and clinical characteristics, as well as the microbiological profile and evolution of patients with acute bacteremic cholangitis, comparing them based upon they were or not biliary stent carriers.

METHODS

We performed a retrospective analysis of all consecutive patients over 18 years-old with a stent placement in our center between 2008 and 2017 were included. We compared them with our prospective cohort of patients with a diagnosis of acute bacteremic cholangitis. Primary outcome was 30-day mortality. Secondary outcome was clinical cure at day 7, 14-day mortality and 90-day recurrence.

RESULTS

Two hundred and seventy-three patients were analyzed, including 156 in the stent-related (SR) and 117 in the stent not-related (SNR) group, respectively. Stent-related colangitis patients were younger, with more comorbidities and with a greater severity of infection. Escherichia coli and Klebsiella pneumonia were the most frequent isolation. Enterococcus spp. was the third most frequent isolation in SR group but were uncommon in SNR patients; where E. coli was the most prevalent microorganism. Septic shock (HR 3.44, 95% [CI 1.18-8.77]), inadequate empirical treatment (HR 2.65, 95% CI [1.38-.7.98]) and advanced neoplasia (HR 2.41, 95% CI [1.55-6.44]) were independent 30-day mortality risk factors. The 90-day recurrence rate significantly higher in those patients with stent-related cholangitis (29% vs. 13%, p=0.016) and stent replacement was associated with lower recurrence rate (HR 0.38, 95% CI [0.11-0.77]).

CONCLUSIONS

Clinical and microbiological profile, as well as outcome of patients with SR and SNR cholangitis were different. In SR group, recurrence rate was high and stent replacement was associated with a lower risk.

Nosocomial Infections in Gastrointestinal Cancer Patients: Bacterial Profile, Antibiotic Resistance Pattern, and Prognostic Factors

Background

Cancers of the gastrointestinal (GI) tract and its associated excretory glands are one of the most common causes of cancer-related death worldwide, and these patients are more likely to developing nosocomial infections due to immunodeficiency.

Objective

To explore the bacterial profile, antibiotic resistance pattern, and prognostic factors of nosocomial infections in hospitalized GI cancer patients.

Methods

All electronic medical records of nosocomial infection episodes in hospitalized GI cancer patients were retrospectively reviewed. In-hospital mortality was used to evaluate the prognosis of patients. Mann–Whitney test, Chi-square test, and binary logistic regression analysis were used to identify potential risk factors for in-hospital mortality. P-values <0.05 were considered statistically significant.

Results

A total of 428 GI cancer patients developed nosocomial infections during hospitalization. Respiratory tract infections (44.2%), bloodstream infections (BSIs) (11.7%), and abdominal cavity infections (11.4%) were the most common infection sites. The predominant causative pathogens were extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (13.6%), ESBL-negative E. coli (11.9%), and Klebsiella pneumoniae (10.0%). Multidrug-resistant (MDR) strains were detected in 27.6% of isolates. Antimicrobial susceptibility analysis showed that the isolated Gram-negative bacteria (GNB) exhibited high sensitivity to amikacin, meropenem, imipenem, and piperacillin/tazobactam, while the isolated Gram-positive bacteria exhibited high sensitivity to tigecycline, linezolid, and vancomycin. The overall in-hospital mortality of all patients was 11.2% in the study. Multivariate analysis showed that ECOG performance status ≥two scores, length of antibiotic treatment <9.0 days, existence of septic shock, and hypoproteinemia were independent risk factors for in-hospital mortality.

Conclusion

The burden of nosocomial infections in GI cancer patients is considerably high, with GNB being predominantly isolated causative pathogens. Surveillance on serum albumin level, adequate antibiotic treatment, early identification, and prompt treatment of septic shock could benefit the prognosis.

Prevalence of Asymptomatic Bacteriuria and Antibiotic Susceptibility Patterns of Bacterial Isolates among Cancer Patients and Healthy Blood Donors at the University of Gondar Specialized Hospital

Background

Urinary tract infections are the common types of infections in the community and health care settings. Despite the widespread availability of antibiotics, urinary tract infection remains a worldwide therapeutic problem. It is a continuous and significant problem in cancer patients.

Methods

A hospital-based comparative cross-sectional study was conducted on 240 study participants from January to June 2019. Sociodemographic data were collected by a predesigned questionnaire and midstream urine samples collected using simple random sampling technique by using clean, sterile plastic cups and then inoculated onto CLED agar plates and incubated at 37°C for 24 hours. Urine culture was considered significant bacteriuria when colony forming units ≥10⁵/mL of voided urine and a single pure colony suspended in nutrient broth and then subcultured onto a blood agar plate and MacConkey agar plate, incubated at 37°C for 24 hours for identification. Identification was done by using standard microbiological methods. Modified Kirby–Bauer disk diffusion technique was applied for antimicrobial susceptibility testing in accordance with CLSI 2018 criteria. Data were entered, cleared, and checked using Epi Info version 7 and exported to SPSS version 20 for analysis. The results were displayed using tables and figures. p value <0.05 at 95% CI was considered as statistically significant.

Results

The overall prevalence of asymptomatic bacteriuria in cancer patients was 23.3% while 6.7% in apparently healthy blood donors. E. coli (32.1%) was the commonest isolated uropathogenic bacteria followed by Klebsiella species (25.0%), S. aureus (21.4%), Enterococcus species (10.7%), Serratia species (7.1%), and Enterobacter aerogenes (3.6%) in cancer patients. In apparently healthy blood donors, E. coli, Klebsiella species, and S. aureus were isolated from 75%, 12.5%, and 12.5%, respectively. Most Gram-negative bacteria were more sensitive to ceftazidime, cefoxitin, nalidixic acid, nitrofurantoin, norfloxacin, ciprofloxacin, and tobramycin, whereas highly resistant to ampicillin, penicillin, tetracycline, and ceftazidime. S. aureus isolates were 100% susceptible to nitrofurantoin.

Conclusions

This study showed a high prevalence of asymptomatic bacteriuria among cancer patients (23.3%) compared to apparently healthy blood donors (6.7%). E. coli was isolated predominately. Nitrofurantoin and ciprofloxacin should be used to treat asymptomatic bacteriuria in the study area.

Pasteurella bacteraemia: Impact of comorbidities on outcome, based on a case series and literature review

OBJECTIVES

Pasteurella bacteraemia is rare, but has been associated with a high mortality rate. The aim of this study was to estimate the impact of comorbidities on patients with Pasteurella bacteraemia.

METHODS

All cases of Pasteurella bacteraemia in adults treated in our centre between January 2008 and December 2017 were included retrospectively and compared with cases identified in a systematic review of the literature via MEDLINE covering the years 1951-2017. The epidemiological, bacteriological, and clinical data were collected, as well as the instances of death after 30 days.

RESULTS

Twenty cases of Pasteurella bacteraemia identified in our centre and 99 cases from the literature review were included. A major comorbidity was found in 80/119 (67.2%) patients. The death rate at 30 days was 31.1%. The most common comorbidities were cirrhosis, immunosuppressive therapy, and malignant diseases. Age was not associated with mortality. On multivariate analysis, the only factor associated with mortality was a major comorbidity (odds ratio 2.78, 95% confidence interval 1.01-7.70; p = 0.04).

CONCLUSIONS

This study confirms the high mortality rate and highlights the importance of the host background, independent of age, in Pasteurella bacteraemia. Clinicians should be aware of the comorbidities in cases of Pasteurella infection, due to the poor prognosis of bacteraemia.

Phosphatidylcholine Biosynthesis in Mitis Group Streptococci via Host Metabolite Scavenging

We lack fundamental information about the composition of the cellular membrane even for the best-studied pathogens of critical significance for human health. The mitis group streptococci are closely linked to humans in health and disease, but their membrane biology is poorly understood. Here, we demonstrate that these streptococci scavenge major human metabolites and use them to synthesize the membrane phospholipid PC. Our work is significant because it identifies a mechanism by which the major human pathogen S. pneumoniae and the primary human oral colonizers S. mitis and S. oralis remodel their membranes in response to host metabolites.

The mitis group streptococci include the major human pathogen Streptococcus pneumoniae and the opportunistic pathogens Streptococcus mitis and Streptococcus oralis, which are human oral cavity colonizers and agents of bacteremia and infective endocarditis in immunocompromised patients. Bacterial membrane lipids play crucial roles in microbe-host interactions; for many pathogens, however, the composition of the membrane is poorly understood. In this study, we characterized the lipidomes of selected species of mitis group streptococci and investigated the mechanistic basis for biosynthesis of the phospholipid phosphatidylcholine (PC). PC is a major lipid in eukaryotic cellular membranes, but it is considered to be comparatively rare in bacterial taxa. Using liquid chromatography-mass spectrometry in conjunction with stable isotope tracing, we determined that mitis group streptococci synthesize PC via a rare host-metabolite-scavenging pathway, the glycerophosphocholine (GPC) pathway, which is largely uncharacterized in bacteria. Our work demonstrates that mitis group streptococci, including S. pneumoniae, remodel their membranes in response to the major human metabolites GPC and lysophosphatidylcholine.

IMPORTANCE We lack fundamental information about the composition of the cellular membrane even for the best-studied pathogens of critical significance for human health. The mitis group streptococci are closely linked to humans in health and disease, but their membrane biology is poorly understood. Here, we demonstrate that these streptococci scavenge major human metabolites and use them to synthesize the membrane phospholipid PC. Our work is significant because it identifies a mechanism by which the major human pathogen S. pneumoniae and the primary human oral colonizers S. mitis and S. oralis remodel their membranes in response to host metabolites.

Infections Due to Multidrug-Resistant Bacteria in Oncological Patients: Insights from a Five-Year Epidemiological and Clinical Analysis

Bacterial infections are frequent complications in cancer patients. Among them, those caused by multidrug-resistant (MDR) bacteria increase morbidity and mortality mainly because of limited therapeutic options. Current knowledge regarding MDR infections in patients with solid tumors is limited. We assessed the epidemiology and risk factors of increased mortality in these patients. In this retrospective five-year single cohort observational study, we included all oncological patients with MDR infections. Cancer-related parameters, comorbidities, prior use of antibiotics, previous surgical interventions and hospitalization, as well as the use of invasive procedures were investigated as potential risk factors causing adverse outcomes. Seventy-three patients with MDR infection were included: 37% with carbapenem-resistant Klebsiella pneumoniae, 24% with oxacillin-resistant Staphylococcus aureus (MRSA) and 21% with carbapenem-resistant Acinetobacter baumanni. Previous colonization with MDR bacteria was detected in 14% patients, while 20% of the patients presented MDR colonization or infection at ward admission. Mortality during the infection episode was 32%. Duration of hospitalization and CRP were statistically significant risk factors of mortality, whereas administration of guided antibiotics was a protective factor. Knowledge of local epidemiology of MDR bacteria can help physicians promptly identify cancer patients at risk of MDR infections and initiate timely effective empirical antibiotic treatment that can eventually improve the overall therapeutic management.

Clinical impact of an educational antimicrobial stewardship program associated with infectious diseases consultation targeting patients with cancer: Results of a 9-year quasi-experimental study with an interrupted time-series analysis

OBJECTIVES

Antibiotic stewardship programs (ASP) have already demonstrated clinical benefits. However, their effectiveness or safety in immunocompromised hosts needs to be proved.

METHODS

An ecologic quasi-experimental study was performed from January 2009 to June 2017 in the Oncology department of a tertiary-care hospital. A stable program of Infectious Diseases consultation (IDC) already existed at this unit, and an educational ASP was added in 2011. Its main intervention consisted of face-to-face educational interviews. Antibiotic consumption was assessed through quarterly Defined Daily Doses (DDD) per 100 occupied bed-days. Mortality was evaluated in patients with bloodstream infections through the quarterly incidence density per 1000 admissions, and the annual mortality rates at 7 and 30-days. Time-trends were analysed through segmented-regression analysis, and the impact of the ASP was assessed through before-after interrupted time-series analysis.

RESULTS

Mortality significantly decreased throughout the study period (-13.3% annual reduction for 7-day mortality rate, p < 0.01; -8.1% annual reduction for 30-day mortality, p = 0.03), parallel to a reduction in antibiotic consumption (quarterly reduction -0.4%, p = 0.01), especially for broader-spectrum antibiotics. The before-after study settled a significant inflexion point on the ASP implementation for the reduction of antibiotic consumption (change in level 0.95 DDD, p = 0.71; change in slope -1.98 DDD per quarter, p < 0.01). The decreasing trend for mortality before the ASP also continued after its implementation.

CONCLUSIONS

The combination of an ASP with IDC improved antibiotic use among patients with cancer, and was accompanied by a reduction of mortality of bacteraemic infections. Implementation of the ASP was necessary to effectively change antibiotic use.

Risk factors for extended-spectrum beta-lactamase-producing Enterobacteriaceae infection causing septic shock in cancer patients with chemotherapy-induced febrile neutropenia

Patients with chemotherapy-induced febrile neutropenia (FN) are vulnerable to extended-spectrum b-lactamase-producing Enterobacteriaceae (ESBL-PE) infection. Early identification of patients suspected to have ESBL-PE infection for empirical carbapenem administration is crucial; nevertheless, risk factors for ESBL-PE causing septic shock remain unclear. We identify factors to predict ESBL-PE in septic shock patients with chemotherapy-induced FN. In this observational, prospectively collected registry-based study, consecutive adult chemotherapy-induced FN patients with septic shock who were admitted to the emergency department between June 2012 and June 2018 were enrolled. Clinical and laboratory data extracted from the septic shock registry were assessed to identify risk factors for ESBL-PE. Of 179 chemotherapy-induced FN septic shock patients, ESBL-PE is isolated in 23 (12.8%). ESBL-PE infection is frequently seen in patients with hepatobiliary cancer (17.4% vs. 4.5%, P = 0.037), leukemia (13.0% vs. 2.6%, P = 0.046), and those with profound neutropenia (defined as absolute neutrophil count < 100) (73.9% vs. 43.6%, P = 0.007) in contrast to those with lung cancer (0% vs. 14.7%, P = 0.048) and other solid cancer (0% vs. 19.2%, P = 0.016). Multivariate logistic regression reveals that profound neutropenia (adjusted OR 3.67; 95% CI 1.372-9.799; P = 0.010) is an independent risk factor for ESBL-PE infection after adjusting age, the presence of solid tumor, and the parameters of sepsis severity scores. ESBL-PE is rare (12.9%) in chemotherapy-induced FN patients with septic shock. Early empirical carbapenem therapy might be considered in chemotherapy-induced FN patients with profound neutropenia.

Prevention of Infection: A Systematic Review of Evidence-Based Practice Interventions for Management in Patients With Cancer

BACKGROUND

Cancer-related infections lead to increases in mortality, antibiotic use, and hospital stays. Other adverse outcomes include dose delays and reductions, which can result in suboptimal treatment outcomes.

OBJECTIVES

Effective implementation of risk assessment and evidence-based interventions for the prevention and treatment of infection are essential to improve care and reduce costs related to infections in patients with cancer receiving immunosuppressive therapy.

METHODS

The Oncology Nursing Society (ONS) Putting Evidence Into Practice (PEP) prevention of infection resource have been developed and updated to identify and disseminate the best available scientific evidence.

FINDINGS

Pharmacologic and nonpharmacologic interventions were evaluated, resulting in recommended for practice rating for catheter care bundles, antimicrobial prophylaxis, vaccination for specific populations, and implementation of contact precautions for resistant organisms.

Epidemiology and Outcomes of Bloodstream Infections in Patients With Solid Tumors in a Central American Population at Mexico Hospital, San Jose, Costa Rica

PURPOSE

Bloodstream infections (BSIs) are an important cause of mortality in patients with solid tumors. We conducted a retrospective study to evaluate the epidemiologic profile and mortality of patients with solid tumors who have BSIs and were admitted to Mexico Hospital. This is the first study in Costa Rica and Central America describing the current epidemiologic situation.

METHODS

We analyzed the infectious disease database for BSIs in patients with solid tumors admitted to Mexico Hospital from January 2012 to December 2014. Epidemiology and mortality were obtained according to microorganism, antibiotic sensitivity, tumor type, and presence of central venous catheter (CVC). Descriptive statistics were used.

RESULTS

A total of 164 BSIs were recorded, the median age was 58 years, 103 patients (63%) were males, and 128 cases of infection (78%) were the result of gram-negative bacilli (GNB). Klebsiella pneumoniae (21%), Escherichia coli (21%), and Pseudomonas aeruginosa (15%) were the most common microorganisms isolated. Gram-positive cocci (GPC) were found in 36 patients, with the most frequent microorganisms being Staphylococcus aureus (10%) and Staphyloccocus epidermidis (6%). With respect to tumor type, BSIs were more frequent in the GI tract (57%) followed by head and neck (9%) and genitourinary tract (8%). Regarding antibiotic susceptibility, only 17% (GNB) expressed extended-spectrum beta-lactamase and 12% (GPC) had methicillin resistance. Patients with CVCs (n = 59) were colonized mainly by GNB (78%). Overall the mortality rate at 30 days was about 30%.

CONCLUSION

GNB are the most frequent cause of BSIs in solid tumors and in patients with CVCs. GI cancers had more BSIs than other sites. Mortality and antibiotic sensitivity remained stable and acceptable during this observational period in this Latin American population.

Current etiology, clinical features and outcomes of bacteremia in older patients with solid tumors

PURPOSE

To assess the etiology, clinical features and outcomes of bacteremia in older patients with solid tumors.

METHODS

All episodes of bacteremia in hospitalized patients with solid tumors were prospectively collected. Patients aged ≥70 years were compared to patients aged <70 years. Risk factors for case-fatality rates in older patients were identified.

RESULTS

We compared 217 episodes of bacteremia involving older patients and 525 occurring in younger patients. Older patients had more frequently other comorbidities, but were less commonly neutropenic and carried less frequently central venous catheters. Bacteremia from an abdominal source was more common in patients ≥70, whereas an endogenous source and catheter-related infection were less frequently observed. Streptococcus bovis group (3.7% vs. 0.8%, p = .01) and Listeria monocytogenes (4.6% vs. 1.9%, p = .04) were more common in older patients, whereas coagulase-negative staphylococci were less frequently found (1.4% vs. 5.3% p = .01). Infection due to multi-drug resistant (MDR) strains was significantly higher in older patients (17.1% vs. 10.9%, p = .02), who in addition, presented higher overall mortality (35.4% vs 27.7%, p = .04). In older patients, lung tumor, neutropenia, and low grade fever were associated with early mortality, whereas comorbidities, corticosteroids, septic shock and inadequate empirical antibiotic therapy were associated with overall mortality.

CONCLUSIONS

We identified remarkable differences in the etiology and sources of bacteremia between older and younger cancer patients with bacteremia. Older patients had more frequent infection due to MDR organisms and presented a higher overall mortality. Corticosteroids and inadequate empirical antibiotic therapy are modifiable factors associated with mortality.

Admissions for antibiotic-resistant infections in cancer patients during first year of cancer diagnosis: a cross-sectional study

In this study, linked Western Australian health data were used to determine presence of an antibiotic-resistant infection (ABRI) for all people diagnosed with a primary invasive cancer in 2009. Of 10 858 cancer cases, 154 (1.42%) had an ABRI. Patients with an ABRI were older (71.5 vs 66 years), and more had died in the year following diagnosis (37.7 vs 20.2%, P < 0.001). The ABRI cohort had a higher proportion of colorectal, genitourinary and haematological cancers (19.5 vs 11.9%; 14.3 vs 9.7% and 16.9 vs 5.8%, respectively). Hospital admissions with an ABRI were longer (22.3 vs 2.9 days, P < 0.001) and had a higher proportion of unplanned admissions (60.3 vs 15.2%), admissions through emergency department (36.8 vs 8.3%) and intensive care admissions (14.9 vs 1.7%, P < 0.001). Patients with solid tumours who developed an ABRI were more likely to have received chemotherapy (35.9 vs 27.8%, P = 0.04). In haematological cancer patients, a greater proportion of the admissions with an ABRI occurred after radiation therapy or chemotherapy (P = 0.01 and P = 0.005, respectively). This study is the first to report population-level data on ABRI in cancer patients. Patients with an ABRI had more hospital admissions and poorer outcomes.

Bloodstream infection in patients with head and neck cancer: a major challenge in the cetuximab era

PURPOSE

To assess the impact of bloodstream infection (BSI) in patients with head and neck cancer (HNC) in the cetuximab era.

METHODS

We prospectively analysed the epidemiology, microbiology and outcomes of 51 BSI episodes occurring in 48 patients with HNC (2006-2017). We performed a retrospective matched-cohort study (1:2) to determine the risk factors for BSI. Finally, we compared patients who died with those who survived to identify risk factors for mortality.

RESULTS

The most frequent HNC localization was the oropharynx (43%), and pneumonia was the most frequent source (25%). Gram-positive BSI occurred in 55% cases, mainly due to Streptococcus pneumoniae (21%), and among Gram-negatives, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae were the most frequent. Hypoalbuminemia (OR 8.4; 95% CI, 3.5-19.9), previous chemotherapy (OR, 3.2; 95% CI, 1.3-7.4) and cetuximab therapy (OR, 2.8; 95% CI, 1.6-6.7) were significant risk factors for BSI. Patients with BSI had a higher overall case-fatality rate than patients without BSI (OR, 4.4; 95% CI, 1.7-11.8). Hypoalbuminemia was an independent risk factor for the early (7 day) and overall (30 day) case-fatalities, with ORs of 0.8 (95% CI, 0.6-0.9) and 0.8 (95% CI, 0.7-0.97), respectively. The presence of comorbidities (OR, 7; 95% CI, 1.4-34) was also an independent risk factor for overall case-fatality.

CONCLUSIONS

BSI causes high mortality in patients with HNC and is most often secondary to pneumonia. It occurs mainly among patients with hypoalbuminemia who receive treatment with cetuximab or chemotherapy. The development of BSI in patients with HNC impairs their outcome, especially in the presence of hypoalbuminemia and comorbidities.

Bloodstream infection caused by S. aureus in patients with cancer: a 10-year longitudinal single-center study

BACKGROUND

Staphylococcus aureus bloodstream infections (SABIs) represent a significant cause of morbidity and mortality in cancer patients. In this study, we compared infection characteristics and evaluated epidemiology and risk factors associated to SABIs and 30-day attributable mortality in cancer patients.

METHODS

Clinical and microbiological data from patients with cancer and positive blood cultures for S. aureus were retrieved during a 10-year period at an oncology reference center. Analyses were performed according to type of malignancy and infection with methicillin-resistant S. aureus (MRSA). Data was evaluated using competing risk analyses to identify risk factors associated to 30-day mortality and used to create a point system for mortality risk stratification.

RESULTS

We included 450 patients and MRSA was documented in 21.1%. Hospital-acquired infection, healthcare-associated pneumonia, and type-2 diabetes were associated to MRSA. In patients with hematologic malignancies, MRSA was more frequent if hospital-acquired, but less likely in primary bacteremia. Variables associated to mortality included abdominal source of infection, hematologic malignancy, MRSA, glucose levels > 140 mg/dL, and infectious endocarditis; catheter removal and initiation of adequate treatment within 48 h of positive blood culture were protective factors. From our designed mortality prediction scale, patients with a score > 3 had a 70.23% (95%CI 47.2-85.3%) probability of infection-related death at 30 days.

CONCLUSION

SABIs are a significant health burden for cancer patients. Risk factors for SABI-related mortality in this population are varied and impose a challenge for management to improve patient's outcomes. Risk stratification might be useful to evaluate 30-day mortality risk.

Molecular Epidemiology of Klebsiella pneumoniae Strains Causing Bloodstream Infections in Adults

Molecular epidemiology of Klebsiella pneumoniae bacteremic strains allows for a better understanding of preventive and therapeutic strategies. Clinical and microbiological characteristics of 348 K. pneumoniae bacteremia cases (2007-2009) were retrospectively characterized by multilocus sequence typing and extended-spectrum beta-lactamases (ESBL) production. Overall, 223 (64.08%) cases were nosocomial (NA), 58 (16.67%) healthcare associated, and 67 (19.25%) community acquired. The main infection origins were urinary tract (16.6%, 50.0%, and 43.3%), biliary tract (10.8%, 24.2%, and 31.3%), and catheter-related infection (39.9%, 5.2%, and 0%). The 30-day mortality rate was around 20%. The rates of resistance were around 45% the highest being among NA cases, and ESBL production was detected in 7.2% of cases. A total of 161 different sequence types were grouped into 13 clonal sets by e-burst analysis. No relationship could be established between clonal sets and the origin of infection or the healthcare-related settings. The high genetic variability among the isolates suggests their intrapatient endogenous origin.

Managing the oncologic patient with suspected pneumonia in the intensive care unit

INTRODUCTION

Solid cancer patients are frequently admitted in intensive care units for critical events. Improving survival rates in this setting is considered an achievable goal today. Respiratory failure is the main reason for admission, representing a primary target for research.

AREAS COVERED

This review presents a diagnostic and therapeutic algorithm for pneumonia and other severe respiratory events in the solid cancer population. It aims to increase awareness of the risk factors and the different etiologies in this changing scenario in which neutropenia no longer seems to be a decisive factor in poor outcome. Bacterial pneumonia is the leading cause, but opportunistic diseases and non-infectious etiologies, especially unexpected adverse effects of radiation, biological drugs and monoclonal antibodies, are becoming increasingly frequent. Options for respiratory support and diagnostics are discussed and indications for antibiotics in the management of pneumonia are detailed. Expert commentary: Prompt initiation of critical care to facilitate optimal decision-making in the management of respiratory failure, early etiological assessment and appropriate antibiotic therapy are cornerstones in management of severe pneumonia in oncologic patients.

Streptococcus mitis and S. oralis Lack a Requirement for CdsA, the Enzyme Required for Synthesis of Major Membrane Phospholipids in Bacteria

Synthesis and integrity of the cytoplasmic membrane are fundamental to cellular life. Experimental evolution studies have hinted at unique physiology in the Gram-positive bacteria Streptococcus mitis and S. oralis These organisms commonly cause bacteremia and infectious endocarditis (IE) but are rarely investigated in mechanistic studies of physiology and evolution. Unlike in other Gram-positive pathogens, high-level (MIC ≥ 256 μg/ml) daptomycin resistance rapidly emerges in S. mitis and S. oralis after a single drug exposure. In this study, we found that inactivating mutations in cdsA are associated with high-level daptomycin resistance in S. mitis and S. oralis IE isolates. This is surprising given that cdsA is an essential gene for life in commonly studied model organisms. CdsA is the enzyme responsible for the synthesis of CDP-diacylglycerol, a key intermediate for the biosynthesis of all major phospholipids in prokaryotes and most anionic phospholipids in eukaryotes. Lipidomic analysis by liquid chromatography-mass spectrometry (LC-MS) showed that daptomycin-resistant strains have an accumulation of phosphatidic acid and completely lack phosphatidylglycerol and cardiolipin, two major anionic phospholipids in wild-type strains, confirming the loss of function of CdsA in the daptomycin-resistant strains. To our knowledge, these daptomycin-resistant streptococci represent the first model organisms whose viability is CdsA independent. The distinct membrane compositions resulting from the inactivation of cdsA not only provide novel insights into the mechanisms of daptomycin resistance but also offer unique opportunities to study the physiological functions of major anionic phospholipids in bacteria.

Infections in Cancer Patients with Solid Tumors: A Review

Solid tumors are much more common than hematologic malignancies. Although severe and prolonged neutropenia is uncommon, several factors increase the risk of infection in patients with solid tumors, and the presence of multiple risk factors in the same patient is not uncommon. These include obstruction (most often caused by progression of the tumor), disruption of natural anatomic barriers such as the skin and mucosal surfaces, and treatment-related factors such as chemotherapy, radiation, diagnostic and/or therapeutic surgical procedures, and the increasing use of medical devices such as various catheters, stents, and prostheses. Common sites of infection include the skin and skin structures (including surgical site infections), the bloodstream (including infections associated with central venous catheters), the lungs, the hepato-biliary and intestinal tracts, and the urinary tract, and include distinct clinical syndromes such as post-obstructive pneumonia, obstructive uropathy, and neutropenic enterocolitis. The epidemiology of most of these infections is changing with resistant organisms [MRSA, Pseudomonas aeruginosa, extended spectrum beta-lactamase (ESBL)-producing organisms] being isolated more often than in the past. Polymicrobial infections now predominate when deep tissue sites are involved. Conservative management of most of these infections (antibiotics, fluid and electrolyte replacement, bowel rest when needed) is generally effective, with surgical intervention being reserved for the drainage of deep abscesses, or to deal with complications such as intestinal obstruction or hemorrhage. Infected prostheses often need to be removed. Reactivation of certain viral infections (HBV, HCV, and occasionally CMV) has become an important issue, and screening, prevention and treatment strategies are being developed. Infection prevention, infection control, and antimicrobial stewardship are important strategies in the overall management of infections in patients with solid tumors. Occasionally, infections mimic solid tumors and cause diagnostic and therapeutic challenges.

Antibiotic Resistance of Non-pneumococcal Streptococci and Its Clinical Impact

The taxonomy of streptococci has undergone major changes during the last two decades. The present classification is based on both phenotypic and genotypic data. Phylogenetic classification of streptococci is based on 16S rRNA sequences [1], and it forms the backbone of the overall classification system of streptococci. Phenotypic properties are also important, especially for clinical microbiologists. The type of hemolysis on blood agar, reaction with Lancefield grouping antisera, resistance to optochin, and bile solubility remain important for grouping of clinical Streptococcus isolates and therefore treatment options [2]. In the following chapter, two phenotypic classification groups, viridans group streptococci (VGS) and beta-hemolytic streptococci, will be discussed.

Characteristics, aetiology, antimicrobial resistance and outcomes of bacteraemic cholangitis in patients with solid tumours: A prospective cohort study

OBJECTIVES

To asses the clinical features, aetiology, antimicrobial resistance and outcomes of bacteraemic cholangitis in patients with solid tumours (ST).

METHODS

All consecutive episodes of bacteraemia in hospitalized patients were prospectively analysed (2006-2015).

RESULTS

Of 1852 episodes of bacteraemia, 750 involved patients with ST. Among them, 173 episodes (23%) were due to cholangitis. The most frequent neoplasms were hepato-biliary-pancreatic tumours (68.2%) and gastrointestinal cancer (18.5%); 57.2% of patients had a biliary stent in place. The most frequent causative agents were Escherichia coli (39.3%) followed by Klebsiella pneumoniae (15.1%) and Enterococcus faecium (7.8%). Forty-one episodes (18.7%) were caused by multidrug-resistant (MDR) microorganisms. Patients with a second episode of cholangitis were more likely to have an MDR isolate and to had received inadequate empirical antibiotic therapy. 7-day and 30-day case-fatality rates were 7.6% and 26%, respectively. The only risk factors independently associated with 30-day case-fatality rate were corticosteroids and malignancy-related complications.

CONCLUSIONS

Bacteraemic cholangitis is frequent in patients with ST, and is mainly caused by Enterobacteriaceae and E. faecium. The emergence of MDR is of special concern, particularly in patients with a second episode of bacteraemia. Case-fatality rates are high, especially among patients receiving corticosteroids and presenting malignancy-related complications.

Selected Topics in Aerobic Bacteriology

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

Increasing Antimicrobial Resistance Monitored in Surveillance Analysis of Blood Stream Infections in Febrile Neutropenic Pediatric Oncology Patients

BACKGROUND

Continuous surveillance of pattern of blood stream infection is necessary in febrile neutropenia (FN)especially with the recent escalating trend in the management of pediatric cancer patients towards intensified regimens and with the increase in infections caused by resistant organisms limiting the choice of antibiotics.

AIM

To monitor change in pattern of blood stream infections (BSI) in FN pediatric cancer patients.

MATERIALS AND METHODS

Surveillance of FN episodes with positive BSI was prospectively monitored and compared to a previous surveillance in the same pediatric oncology unit.

RESULTS

A total of 232 BSI positive episodes were documented in 192 patients during a 6 months period. The results of recent surveillance analysis showed an increase in intensified regimens of chemotherapy, antimicrobial resistance, fungal infections, and prolonged duration of episodes when compared to previous surveillance, with p value sof <0.001, 0.005, 0.021, and <0.001, respectively. There was an apparent decrease in the crude mortality but this was not statistically significant, to 6% in 2011 from 10 % in 2006.

CONCLUSIONS

The pattern of BSI at our institution is still inclining towards gram positive organisms but is showing a shift towards more antibiotic resistance and fungal infections.