Antimicrobial-resistant Gram-negative bacteria in febrile neutropenic patients with cancer: current epidemiology and clinical impact

Epidemiology and microbiology of Gram-negative bloodstream infections in a tertiary-care hospital in Beijing, China: a 9-year retrospective study

Background: Gram-negative bacterial bloodstream infections (BSIs) are associated with high morbidity and mortality. The present study examines the incidence, clinical characteristics, microbiological features, drug resistance and mortality associated with Gram-negative bacterial BSIs at a tertiary-care hospital in Beijing, China.Methods: This retrospective cohort study of patients with Gram-negative bacterial BSIs was performed between 1 January 2010 and 31 December 2018 at the Chinese People^,s Liberation Army General Hospital.Results: A total of 6867 episodes of Gram-negative bacterial BSIs occurred among 3199 patients over 9 years. The overall incidence of Gram-negative bacterial BSIs fluctuated from 2.30 to 2.55 episodes per 1000 admissions over 9 years. Escherichia coli was the major pathogen (34.3%). The antibiotic resistance of ESBLs-producing E. coli was higher than non-ESBLs producing E. coli including the majority of antibiotics, but to carbapenems (0.7% VS 5.1%). Between 2010 and 2018, the overall mortality of Gram-negative bacterial BSIs decreased from 11.41% to 9.05% (X² = 6.95, P = 0.434).Conclusions: Cephalosporins and carbapenem antibiotics were considered as the optimal treatment for patients with Gram-negative bacterial BSIs except for A. baumannii, which was treated according to the drug sensitivity or multidrug combination.

Current spectrum of causative pathogens in sepsis: A prospective nationwide cohort study in Japan

BACKGROUND

There is no one-size-fits-all empiric antimicrobial therapy for sepsis because the pathogens vary according to the site of infection and have changed over time. Therefore, updating knowledge on the spectrum of pathogens is necessary for the rapid administration of appropriate antimicrobials.

OBJECTIVE

The aim of this study was to elucidate the current spectrum of pathogens and its variation by site of infection in sepsis.

METHODS

This was a prospective nationwide cohort study of consecutive adult patients with sepsis in 59 intensive care units in Japan. The spectrum of pathogens was evaluated in all patients and in subgroups by site of infection. Regression analyses were conducted to evaluate the associations between the pathogens and mortality.

RESULTS

The study cohort comprised 1184 patients. The most common pathogen was Escherichia coli (21.5%), followed by Klebsiella pneumoniae (9.0%). However, the pattern varied widely by site of infection; for example, gram-positive bacteria were the dominant pathogen in bone/soft tissue infection (55.7%) and cardiovascular infection (52.6%), but were rarely identified in urinary tract infection (6.4%). In contrast, gram-negative bacteria were the predominant pathogens in abdominal infection (38.4%) and urinary tract infection (72.0%). The highest mortality of 47.5% was observed in patients infected with methicillin-resistant Staphylococcus aureus, which was significantly associated with an increased risk of death (odds ratio 1.88, 95% confidence interval 1.22-2.91).

CONCLUSIONS

This study revealed the current spectrum of pathogens and its variation based on the site of infection, which is essential for empiric antimicrobial therapy against sepsis.

Effect of a dietary supplement composed of hydrolyzed milk proteins and vanillin on the reduction of infection and oxidative stress induced by chemotherapy

This study evaluates the antioxidant and antibacterial activity of a mixture of lactoferrin hydrolysate (LfH), whey protein hydrolysate (WPH) and vanillin in vitro and in vivo to design a chemoprotective supplement for reducing the infection and oxidative stress induced by chemotherapy. The designed supplement showed significant antibacterial activity against E. coli. The supplement with the highest concentration exhibited considerable antioxidant activity in (2,2-diphenyl-1-picrylhydrazyl) DPPH free radicals, (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) ABTS, and reducing power assays. In the biochemical analysis of liver homogenate, the supplement 3 increased the level of enzymes Catalase (CAT), Glutathione peroxidase (GPx), Superoxide dismutase (SOD), and also the Ferric Reducing Ability of Plasma (FRAP) while decreased thiobarbituric acid reactive substances (TBARS) in comparison to paclitaxel group, indicative of activity against oxidative stress. Antibacterial and antioxidant activity of the designed supplement makes it a good candidate for use as a functional food to reduce the side effects of chemotherapy. PRACTICAL APPLICATIONS: A dietary supplement composed of lactoferrin hydrolysate (LfH), whey protein hydrolysate (WPH) and vanillin showed antibacterial activity against E. coli and S. aureus in vitro. The studied supplement also exhibited significant antioxidant properties in the model system and anti-oxidative stress activity in mice exposed to paclitaxel. This supplement has a potential for use in the food matrix to reduce the chemotherapy side effects and to act as a chemoprotective agent.

Microbiological Profile of Blood Stream Infections in Febrile Neutropenic Patients at a Tertiary Care Teaching Hospital in Rishikesh, Uttarakhand

Context  Febrile neutropenia is a serious complication of chemotherapy affecting patients with both hematological and solid malignancies, respectively. To the best of our knowledge, there is paucity of literature from Uttarakhand, India on microbiological profile of blood stream infections (BSIs) in febrile neutropenic patients. Aims  The study aims to generate preliminary data on microbiological profile and antibiotic resistance pattern of BSIs in febrile neutropenic patients. Settings and Design   The design involved cross-sectional study from January 1, 2019 to July 31, 2019. Methods and Materials  Data of nonrepetitive paired peripheral blood samples obtained from 306 consecutive febrile neutropenic cancer patients of all age groups and both sexes, for culture and sensitivity testing, were retrospectively analyzed. All blood samples were subjected to aerobic culture using BACT/ALERT three-dimensional microbial detection system. Growth obtained in culture was identified by conventional biochemical methods. Antibiotic susceptibility testing of bacterial isolates was performed using modified Kirby Bauer disk diffusion method. Statistical Analysis Used   Fisher's exact test was used for the analysis. Results  Mean age ± SD of the study population was 32.39 ± 10.56 years with a male to female ratio of 1.55:1. 74.18% of the blood samples were received from patients suffering from hematological malignancies. Microbiologically confirmed BSIs were observed in 27.1% patients. Gram-negative bacilli were predominantly isolated in culture with Klebsiella spp . being the most common. Percentage resistance values of gram-negative bacilli to aminoglycosides, β-lactam/β-lactamase inhibitor combinations, fluoroquinolones, cephalosporins, carbapenems, chloramphenicol, ampicillin, co-trimoxazole, and doxycycline were 26.6 to 91.7%, 8.3 to 86.6%, 10 to 66.7%, 13.3 to 73.3%, 8.3 to 73.3%, 80 to 93.3%, 13.3 to 20%, 16.7 to 66.6%, and 13.3 to 16.7%, respectively. Conclusion  Implementation of antimicrobial stewardship program along with hospital infection control practices is needed for preventing BSIs due to MDR organisms.

Antimicrobial activity of biosynthesised silver nanoparticles against multidrug-resistant microbes isolated from cancer patients with bacteraemia and candidaemia

Background

In the past years, saprophytic bacteria and candida have been emerging as potential human pathogens causing life-threatening infections in patients with cancer. This study was designed to determine the bacteria and candida species, causing bloodstream infections in cancer patients and the assessment of their susceptibility to antibiotics and biosynthesised silver nanoparticles.

Materials and Methods

Ninety-seven microbial pathogens recovered from blood samples of cancer patients were included in the present study. The microbial isolates were collected in a duration period extending from December 2016 to July 2018 at National Cancer Institute, Cairo, Egypt. The clinical samples were collected using microbiological methods and were cultivated on MacConkey agar, blood agar media and Sabouraud dextrose agar media. The microbial isolates were identified using both standard microbiological methods and VITEK 2 compact automated system. The antibiotic resistance pattern was determined by the VITEK 2 compact automatic system and disk diffusion method, according to the Clinical and Laboratory Standards Institute. The characterisation of nanoparticles was carried out using ultraviolet spectroscopy and electron microscope. The antimicrobial activity of bio (AgNPs) was evaluated.

Results

A total of 97 microbial isolates recovered from collected blood samples from cancer patients were included in the study. Pathogenic bacteria and Candida were represented by 74 isolates (76.22%) and 23 isolates (23.69), respectively. Among the 74 bacterial isolates, Escherichia coli constituted (27.81%), Klebsiella pneumoniae (24.72%), Acinetobacter baummannii (11.33%), Pseudomonas aeruginosa (4.12%), Enterobacter spp. (3.09%) and) Staphylococcus aureus (2.06%). Cedecea davisae (1.03%), Burkholderia cepacia (1.03%) and Pantoea agglomerans (1.03%). Among the 23 Candida isolates, Candida tropicalis constituted (9.27%), Candida albicans (5.15%), Candida glabrata (5.15%) and Candida krusei (4.12%) from the total microbial isolates. The antibiotic susceptibility results revealed that amikacin and gentamycin were the most effective antibiotics against Gram-negative bacteria, while vancomycin and linezolid were most effective against S. aureus. Caspofungin was the most effective against candida species. The obtained stable biosynthesised silver nanoparticles ranged in size from 10 nm to 100 nm and were mostly spherical in shape. These biosilver nanoparticles showed the highest antimicrobial activity against most of the microbial isolates (bacteria and Candida). The in vitro cytotoxicity of biosynthesised AgNPs on HeLa cell lines revealed a dose-dependent potential. The IC50 value of AgNPs was found 6 and 5.6 μg/ml, respectively.

Conclusion

The present study revealed a significant distribution of multidrug-resistant microbes, which may increase the burden of healthcare to prevent infections in cancer patients. Biosilver nanoparticles exhibit antimicrobial activity against multidrug-resistant microbes and could be considered as effective agents against these strains.

Rectal colonization with multidrug-resistant gram-negative bacteria in patients with hematological malignancies: a prospective study

OBJECTIVES

To investigate the risk factors for rectal colonization with carbapenem-resistant Enterobacteriaceae (CRE) and extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBL-E) in hematological malignant patients with febrile neutropenia (FN); rate of rectal colonization and infection/colonization with CRE and ESBL-E; whether empirical treatment can be revised.

METHODS

Adult patients receiving chemotherapy were included. Rectal swab cultures of patients were screened for CRE and ESBL-E using selective chromogenic agars.

RESULTS

Fifty-seven FN episodes of 57 patients were studied. Rectal colonization rates were 40.4% (23/57) and 8.8% (5/57) for ESBL-E and CRE, respectively. ESBL-E bacteremia was diagnosed in 2 (8.6%) ESBL-E colonized patients, while CRE bacteremia was detected in 1 (20%) CRE colonized patient. Amikacin (100%) and carbapenem (93%) were the most effective antibiotics against gram-negative enteric bacteria. Beta-lactam usage within the last 3 months was a significant risk factor for ESBL-E colonization.

CONCLUSIONS

For the treatment of FN patients either colonized with ESBL-E or having significant risk factors for ESBL-E infection, aminoglycoside containing combinations may become an alternative to carbapenems due to their high sensitivity rates. When CRE colonized hematological cancer patients develop FN or if they are hemodynamically unstable, CRE covering empiric antibiotherapy should be preferred due to high mortality rates of CRE bacteremia.

An eleven-year cohort of bloodstream infections in 552 febrile neutropenic patients: resistance profiles of Gram-negative bacteria as a predictor of mortality

Antimicrobial stewardship is of major importance in patients with febrile neutropenia (FN). In this study, we aimed to investigate the trends in resistance and the relationship with mortality rates in patients with FN. The single-center surveillance data of inpatients with FN and diagnosed as microbiologically confirmed bloodstream infections (BSIs) between 2006 and 2016 were reviewed retrospectively. A total of 950 episodes in 552 patients with BSIs were analyzed. Of whom, 55.9% were male, the median age was 43 years, and 35.6% had acute myeloid leukemia. In total, 1016 microorganisms were isolated from blood cultures. Gram-negatives accounted for 42.4% (n = 403) of the episodes. Among Gram-negatives, Enterobacteriaceae accounted for 346 (86%) (E. coli, n = 197; 34% extended-spectrum β-lactamases (ESBL) producers, and Klebsiella spp., n = 120; 48.3% ESBL producers). Also, 24 (20.0%) of Klebsiella spp. had carbapenemase activity. There were 6 (5.0%) colistin-resistant Klebsiella spp. Thirteen (26.5%) of Pseudomonas spp. and 17 (60.7%) of Acinetobacter spp. had carbapenemase activity. There were 2 (5.6%) colistin-resistant Acinetobacter spp. The 30-day mortality rates were 12.0%, 21.5%, 34.6%, and 29.0% in BSIs due to Gram-positive, Gram-negative bacterial, fungal, and polymicrobial etiology respectively (p = 0.001). BSIs with ESBL-producing (p = 0.001) isolates, carbapenem (p < 0.001), and colistin-resistant isolates (p < 0.001) were associated with increased mortality risk. The tremendous rise in resistance rates among Gram-negatives is dreadfully related to increasing mortality and leads to sharp shifts toward extreme restrictions of unnecessary antibiotic uses. Antimicrobial stewardship in patients with FN requires vigilance and tailoring of treatment upon local surveillance data.

Antimicrobial utilization and antimicrobial resistance in patients with haematological malignancies in Japan: a multi-centre cross-sectional study

BACKGROUND

Infection is a major complication for patients with haematological malignancies. It is important to better understand the use of antimicrobial agents and antibiotic resistance for appropriate treatment and prevention of drug resistance. However, very few multi-centre analyses have focused on the use of antimicrobial agents and antibiotic resistance have been carried out in Japan. This study aimed to describe the characteristics of the use of antimicrobial agents and antibiotic resistance in patients with haematological malignancies.

METHODS

We conducted a cross-sectional study using administrative claims data and antimicrobial susceptibility data in Japan. We included patients diagnosed with haematological malignancies, who were hospitalized in a haematology ward between 1 April 2015 and 30 September 2017 in 37 hospitals. Descriptive statistics were used to summarize patient characteristics, antimicrobial utilization, bacterial infections, and antibiotic resistance.

RESULTS

In total, 8064 patients were included. Non-Hodgkin lymphoma (50.0%) was the most common malignancy. The broad-spectrum antibiotics displayed a following antimicrobial use density (AUD): cefepime (156.7), carbapenems (104.8), and piperacillin/tazobactam (28.4). In particular, patients with lymphoid leukaemia, myeloid leukaemia, or myelodysplastic syndromes presented a higher AUD than those with Hodgkin lymphoma, non-Hodgkin lymphoma, or multiple myeloma. The most frequent bacterial species in our study cohort was Escherichia coli (9.4%), and this trend was also observed in blood specimens. Fluoroquinolone-resistant E. coli (3.6%) was the most frequently observed antibiotic-resistant strain, while other antibiotic-resistant strains were rare.

CONCLUSIONS

Broad-spectrum antibiotics were common in patients with haematological malignancies in Japan; however, antibiotic-resistant bacteria including carbapenem-resistant or multidrug-resistant bacteria were infrequent. Our results provide nationwide, cross-sectional insight into the use of antimicrobial agents, prevalence of bacteria, and antibiotic resistance, demonstrating differences in antimicrobial utilization among different haematological diseases.

Ceftazidime/Avibactam and Ceftolozane/Tazobactam for Multidrug-Resistant Gram Negatives in Patients with Hematological Malignancies: Current Experiences

Patients suffering from hematological malignancies are at high risk for severe infections, including in particular bloodstream infections, which represent one of the most frequent life-threatening complications for these patients, with reported mortality rates reaching 40%. Furthermore, a worrisome increase in antimicrobial resistance of Gram-negative bacteria (e.g., cephalosporin- and/or carbapenem-resistant Enterobacteriaceae and multidrug-resistant (MDR) Pseudomonas aeruginosa) involved in severe infectious complications among patients with hematological malignancies has been reported during the last years. The two novel combination of cephalosporins and β-lactamase inhibitors, ceftolozane/tazobactam and ceftazidime/avibactam, were recently approved for treatment of complicated intra-abdominal and urinary tract infections and nosocomial pneumonia and display activity against several MDR Gram-negative strains. Although not specifically approved for neutropenic and/or cancer patients, these drugs are used in this setting due to increasing rates of infections caused by MDR Gram-negative bacteria. The aim of this review is to describe the actual evidence from scientific literature about the "real-life" use of these two novel drugs in patients with hematological malignancies and infections caused by MDR Gram-negative bacteria.

Proposal of a clinical score to stratify the risk of multidrug-resistant gram-negative rods bacteremia in cancer patients

Introduction

Multidrug-resistant gram-negative rods (MDR GNR) represent a growing threat for patients with cancer. Our objective was to determine the characteristics of and risk factors for MDR GNR bacteremia in patients with cancer and to develop a clinical score to predict MDR GNR bacteremia.

Material and Methods

Multicenter prospective study analyzing initial episodes of MDR GNR bacteremia. Risk factors were evaluated using a multiple logistic regression (forward-stepwise selection) analysis including variables with a p < 0.10 in univariate analysis.

Results

394 episodes of GNR bacteremia were included, with 168 (42.6 %) being MDR GNR. Five variables were identified as independent risk factors: recent antibiotic use (OR = 2.8, 95 % CI 1.7–4.6, p = 0.001), recent intensive care unit admission (OR = 2.9, 95 % CI 1.1–7.8, p = 0.027), hospitalization ≥ 7 days prior to the episode of bacteremia (OR = 3.5, 95 % CI 2–6.2, p = 0.005), severe mucositis (OR = 5.3, 95 % CI 1.8–15.6, p = 0.002), and recent or previous colonization/infection with MDR GNR (OR = 2.3, 95 % CI 1.2–4.3, p = 0.028). Using a cut-off value of two points, the score had a sensitivity of 66.07 % (95 % CI 58.4–73.2 %), a specificity of 77.8 % (95 % CI 71.4–82.7 %), a positive predictive value of 68 % (95 % CI 61.9–73.4 %), and a negative predictive value of 75.9 % (95 % CI 71.6–79.7 %). The overall performance of the score was satisfactory (AUROC 0.78; 95 % CI 0.73-0.82). In the cases with one or none of the risk factors identified, the negative likelihood ratio was 0.18 and the post-test probability of having MDR GNR was 11.68 %.

Conclusions

With the growing incidence of MDR GNR as etiologic agents of bacteremia in cancer patients, the development of this score could be a potential tool for clinicians.

Antimicrobial Stewardship in Hematological Patients at the intensive care unit: a global cross-sectional survey from the Nine-i Investigators Network

A global cross-sectional survey was performed to gather data on the current treatment of infections caused by multidrug-resistant (MDR) bacteria among hematological patients admitted to ICUs worldwide. The survey was performed in April 2019 using an electronic platform (SurveyMonkey®) being distributed among 83 physicians and completed by 48 (57.8%) responders. ESBL Enterobacteriaceae, carbapenem-resistant K. pneumoniae and carbapenem-resistant P. aeruginosa were the main concerns. Previous MDR infection (34% of responders), MDR colonization (20%) and previous antibiotic exposure within the last 3 months (20.5%) were considered the most relevant risk factors of bloodstream infection (BSI) due to MDR bacteria. In 48.8% of the ICUs, there was no antimicrobial stewardship (AMS) team focused on hematological patients. Updates on local epidemiology of MDR pathogens were provided in 98% of the centers, using phone or verbal communications (56.1% and 53.7%, respectively). In presence of febrile neutropenia, initial therapy consisted of anti-Gram-negative plus anti-Gram-positive antibiotics for 41% of participants. Antibiotic de-escalation and/or discontinuation of therapy were considered as a promising strategy for the prevention of MDR development (32.4%). Factors associated with antibiotic de-escalation were clinical improvement (43.6%) and neutrophil count recovery (12.8%). Infectious Disease consultation and AMS interventions were not determining factors for de-escalation decisions (more than 50% of responders). Infection control and educational programs were valued as necessary measures for implementation by ICU practitioners. These findings should guide future efforts on collaborative team working, improving compliance with adequate treatment protocols, implementing antimicrobial stewardship programs in critically ill hematological patients, and educational activities.

Bloodstream infections caused by Escherichia coli in onco-haematological patients: Risk factors and mortality in an Italian prospective survey

Bloodstream infections (BSIs) remain life-threatening complications in the clinical course of patients with haematological malignancies (HM) and Escherichia coli represent one of the most frequent cause of such infections. In this study, we aimed to describe risk factors for resistance to third generation cephalosporins and prognostic factors, including the impact of third generation cephalosporins resistance, in patients with HM and BSIs caused by E. coli. Three hundred forty-two cases of E. coli BSIs were collected during the study period (from January 2016 to December 2017). The percentage of resistance to third generation cephalosporins was 25.7%. In multivariate analysis, the variables recent endoscopic procedures, culture-positive surveillance rectal swabs for multidrug-resistant bacteria, antibiotic prophylaxis with fluoroquinolones, and prolonged neutropenia were independently associated with bloodstream infections caused by a third generation cephalosporins resistant E. coli. The overall 30-day mortality rate was 7.1%. Cox regression revealed that significant predictors of mortality were acute hepatic failure, septic shock, male sex, refractory/relapsed HM, and third generation cephalosporins resistance by E. coli isolate. In conclusion, resistance to third generation cephalosporins adversely affected the outcomes of bloodstream infections caused by E. coli in our cohort of HM patients. We also found a significant correlation between prophylaxis with fluoroquinolones and resistance to third generation cephalosporins by E. coli isolates.

Bloodstream infections in neutropenic patients with haematological malignancies

BACKGROUND

Patients with haematological malignancies have higher risk of acquiring bloodstream infection (BSI). Neutropenia resulting from cytotoxic chemotherapy is the most common risk factor. Infections can progress rapidly with poor outcomes. Understanding the epidemiology may enable prevention and effective management. We investigated and compared the incidence of BSI amongst patients with haematological malignancies and neutropenia and examined the changing spectrum of organisms, and their antimicrobial profiles.

METHODS

BSI data between July 1st 2009 and June 30th 2015 was reviewed.

RESULTS

Three hundred and fifty five BSI were identified in 255 neutropenic patients. Acute myeloid leukaemia (AML) accounted for 40%, Non-Hodgkin's lymphoma for 22% and Acute lymphocytic leukaemia (ALL) for 11.8%. A neutrophil count of <500 cells/μL was present in 93.2%. The overall incidence was 5.40 BSI per 1000 Haematology Occupied Bed days (OBD). Viridans streptococci and Enterococcus species were the most predominant Gram-positives. Vancomycin resistant Enterococcus faecium (VRE) emerged as the predominant Enterococcus species during the study period. Escherichia coli was the most predominant Gram-negative and Extended-spectrum beta-lactamases (ESBL) were detected in 7.1% of isolates. Amongst the Enterobacteriaceae and Pseudomonas aeruginosa dual resistance to Piperacillin-tazobactam and Gentamicin was detected in 5.4%.

CONCLUSION

Our incidence of BSI was 5.40 per 1000 OBD, however variability in reporting of rates in neutropenic patients with haematological malignancies makes comparison between studies difficult, highlighting the need for rate reporting standardization. The epidemiology of organisms causing BSI has changed over time. There is a trend towards an increasing incidence of VRE and multidrug resistant Gram-negatives.

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.

Bacterial Spectrum and Antimicrobial Resistance Pattern in Cancer Patients with Febrile Neutropenia

Background: Bacterial bloodstream infections are one of the most common complications in cancer patients under treatment. Bacteremia in these patients is a medical crisis that needs antibiotic treatment. The aim of this study was to determine bacterial spectrum and antimicrobial resistance pattern in febrile neutropenic cancer patients. Methods: In this prospective study, 212 cancer patients with febrile neutropenia who were referred to Shahid Sadoughi hospital in Yazd from 2012 to 2015 were participated. Bacterial pathogens isolated by the BACTEC media and antimicrobial susceptibility tests performed according to Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: The mean age of patients was 43.5 ± 24.98 years old. Out of 212 participants, 62.3℅ (132/212) were suffering from hematologic malignancies, and 37.7℅ (80/212) had solid tumors. Gram-negative bacteria were the predominant microorganisms (84.9℅). E.coli was the most frequently isolated pathogen (38.68 %), followed by Klebsiella (14.15℅) and Acinetobacter species (11.32℅). In addition, Staphylococcus epidermidis was the most common isolated Gram-positive bacteria (8.5℅). Gram-negative bacteria were susceptible to ciprofloxacin with a response range of 53.7% to 100%. The majority of E.coli isolates were sensitive to ceftazidime (87.8℅) and were resistance to Co-trimoxazole (15.8℅). Klebsiella isolates were 100% susceptible to cephalosporins, meropenem and imipenem. Conclusion: The majority of bacterial pathogens were resistance to various antibiotics. Judicious use of antibiotic therapy can prevent the emergence and spread of antibiotic-resistant Gram-negative bacteria.

MMP-10 and TIMP-1 as indicators of severe sepsis in adult hematological patients with febrile neutropenia

Commonly used indicators of sepsis are nonspecific and insufficient for predicting the course of febrile neutropenia (FN) in hematological patients. We analyzed data from 91 adult FN patients who received intensive chemotherapy for acute myeloid leukemia or autologous stem cell transplantation. Compared to patients with non-severe sepsis, patients with severe sepsis had significantly higher serum levels of tissue inhibitor of metalloproteinases-1 on the day of first occurrence of fever (day 0: 172 vs. 112 µg/L, p= .002) and for the two following days (day 1: 219 vs. 128 µg/L, p< .001; day 2: 443 vs. 128 µg/L, p= .001), and significantly higher serum levels of matrix metalloproteinase-10 on day 1 (1975 vs. 876 ng/L, p= .001) and day 2 (2020 vs. 841 ng/L, p< .001). We conclude that the measurement of these biomarkers may be useful in predicting the severity of sepsis in FN patients.

Neutropénie fébrile aux urgences, stratification du risque et conditions du retour à domicile

La neutropénie fébrile (NF) est une situation fréquemment rencontrée aux urgences avec un taux de mortalité non négligeable variant de 5 à 40 %. Cette variabilité importante met en avant l’importance de stratifier le risque afin de permettre un traitement ambulatoire per os de certains patients à faible risque. En plus du MASCC (The Multinational Association for Supportive Care in Cancer) score, d’autres outils permettent d’évaluer ce risque ou sont à l’étude dans ce but, tels que le dosage de la CRP, la procalcitonine ou encore le score CISNE. Après une prise en charge rapide aux urgences incluant l’administration sans délai d’un traitement adéquat, la poursuite de l’antibiothérapie per os à domicile est envisageable chez les patients à faible risque. La combinaison amoxicilline–acide clavulanique et ciprofloxacine est le plus souvent recommandée, mais la moxifloxacine ou la lévofloxacine en monothérapie peuvent également être utilisées pour les patients traités à domicile. Le retour à domicile permet de réduire fortement les coûts engendrés par l’hospitalisation, de diminuer le risque d’infection nosocomiale et d’améliorer la qualité de vie des patients avec NF à faible risque. Dans cette optique, plusieurs critères doivent être remplis, et une discussion avec le patient reste primordiale à la prise de décision. Parmi ceux-ci, nous retiendrons notamment un score MASCC supérieur à 21, une durée attendue de neutropénie inférieure à sept jours, l’accord du patient et de son entourage ainsi que la proximité entre le domicile et un service de soin adapté.

Risk factors for community-onset bloodstream infection with extended-spectrum β-lactamase-producing Enterobacteriaceae: national population-based case-control study

OBJECTIVES

The aim was to investigate risk factors for community-onset bloodstream infections with extended-spectrum β-lactamase-producing Enterobacteriaceae (EPE BSI).

METHODS

It is mandatory to report EPE BSI to a national register at the Public Health Agency of Sweden. Using this register, we performed a population-based case-control study from 2007 to 2012 of 945 cases and 9390 controls. Exposure data on comorbidity, hospitalization, in- and outpatient antibiotic consumption and socio-economic status were collected from hospital and health registers.

RESULTS

The overall incidence of EPE BSI was 1.7 per 100 000 person-years. The 30-day mortality was 11.3%. Urological disorders inferred the highest EPE BSI risk, adjusted odds ratio (aOR) 4.32 (95% Confidence Interval (CI) 3.41-5.47), followed by immunological disorders, aOR 3.54 (CI 2.01-6.23), haematological malignancy, aOR 2.77 (CI 1.57-4.87), solid tumours, aOR 2.28 (1.76-2.94) and diabetes, aOR 2.03 (1.58-2.61). Consumption of fluoroquinolones or mostly non-EPE-active antibiotics with selective Gram-negative spectrum of activity within the previous 3 months was associated with EPE BSI, aORs 5.52 (CI 2.8-11.0) and 3.8, CI 1.9-7.7) respectively. There was a dose-response relationship in EPE BSI risk with increasing number of consecutive regimens. Antibiotic consumption >3 months before EPE BSI was not associated with increased risk. Higher age, malignancies and education ≤12 years (aORs >2) were associated with increased 30-day mortality.

CONCLUSIONS

Targeted interventions should be directed towards improving care for patients with immunosuppression, urological disorders and subjects with lower socio-economic status. Antibiotic stewardship should focus on reduction of fluoroquinolones.

An in-depth analysis of nosocomial bloodstream infections due to Gram-negative bacilli: clinical features, microbiological characteristics and predictors of mortality in a 1 year, prospective study in a large tertiary care Italian hospital

BACKGROUND

Bloodstream infections (BSI) due to Gram negative bacilli (GNB) represent a major concern among nosocomial infections, since they are noticeably associated with a high mortality rates, increase of healthcare costs and prolongation of hospital stay.

METHODS

Over a 12-month period (2014-2015) all the adult patients admitted to a university-based Italian hospital were monitored for development of BSIs due to GNB. Multiple logistics regression models were performed to assess the impact of patients' risk factors on the in-hospital and 14-day mortality.

RESULTS

During the study period 208 patients were diagnosed with at least a BSI due to a Gram negative species for an incidence rate of 12.8 cases/1,000 admissions (95%CI: 11.2-14.7). Multivariate analyses showed that multiple organ dysfunctions along with immune deficit and inadequate therapy in the first 48hrs were associated with a higher risk of death.

CONCLUSIONS

A thorough evaluation of both immune status and organ dysfunction at the onset of septic events, along with adequate antimicrobial therapy appear to be the most reliable factors in predicting the outcome in these infections. SOFA score can be efficaciously substituted to the single organ dysfunctions analysis in predicting mortality after these events.

SEOM clinical practice guideline: management and prevention of febrile neutropenia in adults with solid tumors (2018)

Febrile neutropenia (FN) is a common dose-limiting toxicity of chemotherapy, with a profound impact on the evolution of patients with cancer, due to the potential development of serious complications, mortality, delays, and decrease in treatment intensity. This article seeks to present an updated clinical guideline, with recommendations regarding the diagnosis, prevention, and treatment of febrile neutropenia in adults with solid tumors. The aspects covered include how to properly approach the risk of microbial resistances, epidemiological aspects, considerations about the initial empirical approach adapted to the risk, special situations, and prevention of complications. A decision-making algorithm is included for use in the emergency department based on a new, validated tool, the Clinical Index of Stable Febrile Neutropenia, which can be used in patients with solid tumors who appear stable in the initial phase of neutropenic infections, and can help detect those at high risk for complications in whom early discharge must be avoided.

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

BACKGROUND

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

OBJECTIVE

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

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.

Prescribing Empiric Antibiotics for Febrile Neutropenia: Compliance with Institutional Febrile Neutropenia Guidelines

Background: Febrile neutropenia (FN) is an oncologic emergency which should be treated immediately with empiric antibiotics. Different institutions observe different antibiograms and use different FN management guidelines. Our center implemented FN management guidelines for adult cancer patients in 2009. Hence, we decided to assess compliance with FN management guidelines and to describe the pattern of bacterial infections. Method: We conducted a cross-sectional study on all adult cancer patients admitted with FN. Data were collected from electronic medical records between January and December 2014. Results: One hundred FN episodes met the study inclusion criteria. The mean age of the patients was 41 ± 17 years; 52% (52 patients) were women. The most common diagnosis was lymphoma (33%). In terms of compliance to institutional FN guidelines, 55% of patients received guideline non-compliant treatment. The most common non-compliant treatment was incorrect amikacin dosing in 31% of patients, followed by incorrect vancomycin dosing in 20%, incorrect piperacillin/tazobactam dosing in 19%, inappropriate use of carbapenems in 18%, and non-compliant vancomycin use in 12% of patients. Bacterial isolates were only observed in 19% of the FN episodes. Among these 19 episodes of FN, Gram-negative pathogens were predominant and were identified in 74% of the episodes, followed by Gram-positive pathogens in 16% and polymicrobial pathogens in 10%. The mean time to defervescence was 2.21 ± 2 days. Conclusion: Our study concluded that there was a high percentage of non-compliance with our institutional FN management guidelines. We recommend following appropriate empiric antibiotic doses and indications as per institutional guidelines.

Bloodstream infections with gram-negative organisms and the impact of multidrug resistance in patients with hematological malignancies

Infections and especially blood stream infections (BSI) with gram-negative bacteria (GNB) represent a major threat for patients with hematological diseases undergoing chemotherapy and mainly contribute to morbidity and mortality. In this retrospective single-center study, we analyzed the impact of BSI with different gram-negative multidrug-resistant bacteria (MDRGN) compared to BSI with antibiotic susceptible gram-negative bacteria. Data of 109 patients with hematological malignancies and GNB BSI were analyzed with overall survival (OS) 30 days after BSI being the primary endpoint. BSI with non-fermentative gram-negative bacteria were found in 26.6% of all patients and 73.4% suffered from a BSI with an Enterobacteriaceae. Thirty-two of 109 patients suffered from BSI with MDRGN. Characteristics of MDRGN and non-MDRGN BSI patients did not differ besides the fact that significantly more patients received an immunosuppressive therapy in the MDRGN BSI group. OS (30 days after BSI) of patients with MDRGN BSI was significantly lower (85.6 vs. 55.9%; p < 0.001) compared to patients with non-MDRGN BSI. Patients with MDRGN BSI with non-fermentative pathogens had a worse OS after 30 days compared to MDRGN BSI with Enterobacteriaceae and the same holds true for non-MDRGN BSI. In multivariate analysis of MDRGN BSI, non-fermenters and ICU admission were independently associated with increased 30-day mortality. Our data demonstrate the negative impact of non-fermentative gram-negative pathogens causing BSI compared to Enterobacteriaceae in hematological patients and thereby underlining the heterogeneity of gram-negative BSI.

Ceftolozane-tazobactam therapy for multidrug-resistant Pseudomonas aeruginosa infections in patients with hematologic malignancies and hematopoietic-cell transplant recipients

Multidrug-resistant (MDR) Pseudomonas aeruginosa infection causes significant mortality among patients with hematologic malignancies and hematopoietic-cell transplant recipients. Ceftolozane-tazobactam (C-T) is a novel therapeutic option for MDR-P. aeruginosa infections but clinical experience in these patients is limited. We report favorable clinical outcomes and lack of limiting toxicities using C-T monotherapy to treat invasive MDR-P. aeruginosa infections in these patient populations.

Does ciprofloxacin prophylaxis during chemotherapy induce intestinal microflora resistance to ceftazidime in children with cancer?

To determine the susceptibility and minimal inhibitory concentrations (MIC) of ceftazidime, the commonly used empirical antibiotic in patients with febrile neutropenia, in Escherichia coli and Klebsiella pneumoniae isolated from the intestinal microflora of pediatric patients with cancer, who received ciprofloxacin prophylaxis during chemotherapy, children younger than 18 years with acute lymphoblastic leukemia or lymphoma scheduled to undergo chemotherapy were randomized to receive oral ciprofloxacin 20 mg/kg/day or placebo from the beginning of their chemotherapy. Rectal swab cultures were taken before (R0) and at 1 (R1), 2 (R2), and 3 (R3) weeks during the intervention. The antimicrobial susceptibilities and MICs of ceftazidime and ciprofloxacin were determined via the E test. Of the total 87 patients enrolled, 44 received ciprofloxacin and 43 placebo. A total of 350 isolates were obtained, 62, 49, 46 and 22 from the ciprofloxacin group and 68, 54, 38 and 11 from the placebo group at R0, R1, R2 and R3, respectively. The percentages of ceftazidime susceptibility did not show significantly greater decreases from R0 to R1-R3 in the ciprofloxacin group compared to the placebo group. The MIC₅₀s of ceftazidime showed significantly greater increases after ciprofloxacin prophylaxis during R1-R3 compared to R0 in the intervention group compared to the placebo group (R0, 0.12 vs. 0.12; R1, 0.19 vs. 0.12; R2, 0.19 vs. 0.12 and R3, 0.38 vs. 0.09 μg/mL, respectively). Due to the increasing MIC₅₀ of ceftazidime over time after ciprofloxacin prophylaxis, the use of ceftazidime in patients who have previously had ciprofloxacin prophylaxis needs to be closely monitored.

Systematic review: human gut dysbiosis induced by non-antibiotic prescription medications

BACKGROUND

Global prescription drug use has been increasing continuously for decades. The gut microbiome, a key contributor to health status, can be altered by prescription drug use, as antibiotics have been repeatedly described to have both short-term and long-standing effects on the intestinal microbiome.

AIM

To summarise current findings on non-antibiotic prescription-induced gut microbiome changes, focusing on the most frequently prescribed therapeutic drug categories.

METHODS

We conducted a systematic review by first searching in online databases for indexed articles and abstracts in accordance with PRISMA guidelines. Studies assessing the intestinal microbiome alterations associated with proton pump inhibitors (PPIs), metformin, nonsteroidal anti-inflammatory drugs (NSAIDs), opioids, statins and antipsychotics were included. We only included studies using culture-independent molecular techniques.

RESULTS

Proton pump inhibitors and antipsychotic medications are associated with a decrease in α diversity in the gut microbiome, whereas opioids were associated with an increase in α diversity. Metformin and NSAIDs were not associated with significant changes in α diversity. β diversity was found to be significantly altered with all drugs, except for NSAIDs. PPI use was linked to a decrease in Clotridiales and increase in Actinomycetales, Micrococcaceae and Streptococcaceae, which are changes previously implicated in dysbiosis and increased susceptibility to Clostridium difficile infection. Consistent results showed that PPIs, metformin, NSAIDs, opioids and antipsychotics were either associated with increases in members of class Gammaproteobacteria (including Enterobacter, Escherichia, Klebsiella and Citrobacter), or members of family Enterococcaceae, which are often pathogens isolated from bloodstream infections in critically ill patients. We also found that antipsychotic treatment, usually associated with an increase in body mass index, was marked by a decreased ratio of Bacteroidetes:Firmicutes in the gut microbiome, resembling trends seen in obese patients.

CONCLUSIONS

Non-antibiotic prescription drugs have a notable impact on the overall architecture of the intestinal microbiome. Further explorations should seek to define biomarkers of dysbiosis induced by specific drugs, and potentially tailor live biotherapeutics to counter this drug-induced dysbiosis. Many other frequently prescribed drugs should also be investigated to better understand the link between these drugs, the microbiome and health status.

[Clinical and bacteriological analysis of lymphoid tissue neoplasms patients with bacteria bloodstream infections]

Objective: To investigate the clinical status of lymphoid tissue neoplasms patients with bacteria bloodstream infections, bacteriology and drug susceptibility results, and provide the basis for rational clinical anti-infection option. Methods: A retrospectively analysis of clinical data and bacterial susceptibility test results of patients with bacteria bloodstream infections from September 2010 to December 2014 was conducted. Results: A total of 134 cases including 107 patients with bloodstream infections were enrolled. 84 cases were male, 50 cases were female, the median age was 31 (12-71) years old. 112 cases were agranulocytosis, and 106 cases were severe agranulocytosis (ANC<0.1×10(9)/L) . 27 cases underwent hematopoietic stem cell transplantation, 100 cases received chemotherapy[33 cases with VD (I) CP±L (vincristine+daunorubicin/idarubicin + cyclophosphamide + prednison±asparaginasum) induction chemotherapy, 41 cases with intensive chemotherapy of Hyper-CVAD/MA or MA (mitoxantrone+cytarabine) , 26 cases with other chemotherapy regimens], and 7 cases were infected without chemotherapy. 10 patients discharged from hospital owing to treatment abandoning, 120 cases were cured through anti-infective therapy, 2 patients died of bacteria bloodstream infections, 1 patient died of sudden cardiac, and 1 patient died of GVHD after allogenic hematopoietic stem cell transplantation. A total of 144 strains were isolated, including 108 strains (75.0%) of Gram-negative bacteria and 36 strains (25.0%) of Gram-positive cocci. The susceptibility of Gram-negative bacteria to the carbapenems was 98.00%, and the adjustment treatment rate of carbapenems was 3.0%. The susceptibility of Gram-negative bacteria to the other antibiotics was 60.30%, and the adjustment treatment rate was 90.5%. The susceptibility of Grampositive cocci to the carbapenems was 49.3%, and to glycopeptides and linezolid was 100.0%. Comparing all patients'empirical use of antimicrobial agents with the drugs susceptibility results of blood cultures, 80.1% of the patients'initial drug selection was sensitive. Conclusion: The lymphoid neoplasms patients experienced bacteria bloodstream infections most often after receiving the chemotherapy regimens of treating acute lymphoblastic leukemia. The majority type of bacteria was Gram-negative bacteria. Drug susceptibility test showed that susceptibility of Gram-negative bacteria to the carbapenems was the highest, and the treatment adjustment rate was obviously lower. The susceptibility of Gram-positive cocci to glycopeptides and linezolid was high, and which could be applied to the patients with Gram-positive cocci sepsis on basis of susceptibility results in general.

Clinical outcomes and nephrotoxicity of colistin loading dose for treatment of extensively drug-resistant Acinetobacter baumannii in cancer patients

Background

Colistin is a last-line defense therapy against extensively drug-resistant Acinetobacter baumannii (XDR-AB). Despite a loading dose of colistin being applied in many clinical practices, studies evaluating the effect of the loading dose of colistin in cancer patients remain limited.

Patients and methods

A retrospective cohort study of cancer patients who received either a loading or non-loading dose of colistin for treatment of XDR-AB was conducted. For each group, the clinical response, bacteriological eradication and serum creatinine were recorded. Logistic regression was applied to evaluate the effects of therapy on each of the three aforementioned outcomes.

Results

One hundred and two patients diagnosed with XDR-AB infections between January 2012 and December 2015 were recruited. Only 75 patients were given a loading dose of colistin. There was no significant clinical and microbiological response in patients in the loading dose group or patients in the non-loading dose group. However, 38 (50.67%) patients in the loading dose group and 6 (22.22%) patients in the non-loading dose group developed nephrotoxicity according to the RIFLE criteria (p = 0.013). Multivariate logistic regression analysis showed that independent predictors of clinical response were Charlson score ≥4 and duration of colistin treatment ≥10 days. Septic shock correlated with both poor clinical and microbiological response. Independent predictors for nephrotoxicity were loading dose colistin and patient’s age ≥60 years.

Conclusion

Administration of colistin loading dose did not significantly increase clinical response, microbiological response or mortality rate compared to non-loading dose in cancer patients with XDR-AB-related infections. However, nephrotoxicity was significantly higher when patients received loading dose colistin.

Antibiotic-Resistant Infections and Treatment Challenges in the Immunocompromised Host

This article reviews antibiotic resistance and treatment of bacterial infections in the growing number of patients who are immunocompromised: solid organ transplant recipients, the neutropenic host, and persons with human immunodeficiency virus and AIDS. Specific mechanisms of resistance in both gram-negative and gram-positive bacteria, as well as newer treatment options are addressed elsewhere, and are only briefly discussed in the context of the immunocompromised host.

Impact of the Microbiota on Bacterial Infections during Cancer Treatment

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

Low rates of antibiotic resistance and infectious mortality in a cohort of high-risk hematology patients: A single center, retrospective analysis of blood stream infection

Febrile neutropenia (FN) is a medical emergency and can represent a life-threatening complication for hematology patients treated with intensive chemotherapy regimens. In clinical practice, the diagnostic yield of blood cultures and other investigations which aim to identify a causative organism or site of infection is low. We have retrospectively examined all blood cultures collected in a “real world” cohort of patients receiving chemotherapy for acute leukemia and patients with aggressive lymphoma treated with Hyper-CVAD/MTX-cytarabine, at a single tertiary center over a five-year period. In this cohort, the 30-day mortality following confirmed blood stream infection (BSI) was 5.9%, which is lower than most reports in the recent literature. We compared the blood culture results of inpatients undergoing induction chemotherapy and outpatients presenting with fevers and found a significantly higher rate of proven BSI in the outpatient group. In all settings, gram-negative organisms were most common. The rate of resistance to first-line empiric antibiotics among pathogenic isolates was 11.6% in the whole cohort, independent of blood culture circumstances. There was a trend to higher resistance rates among inpatients undergoing induction chemotherapy compared to patients presenting to the emergency department (17.4% vs 7.5%) but this did not reach statistical significance. We also report low rates of ciprofloxacin resistance (5% of isolates), in a center where universal fluoroquinolone prophylaxis is not employed. Our low resistance and mortality rates support our current therapeutic strategies, however presence of resistant organisms across the spectrum of indications for BC collection highlights the importance of surveilling local patterns, escalating antimicrobial therapy in the deteriorating patient, and considering advanced techniques for the rapid identification of resistance in this patient population.

Emergencies in Hematology and Oncology

The development of medical emergencies related to the underlying disease or as a result of complications of therapy are common in patients with hematologic or solid tumors. These oncological emergencies can occur as an initial presentation or in a patient with an established diagnosis and are encountered in all medical care settings, ranging from primary care to the emergency department and various subspecialty environments. Therefore, it is critically important that all physicians have a working knowledge of the potential oncological emergencies that may present in their practice and how to provide the most effective care without delay. This article reviews the most common oncological emergencies and provides practical guidance for initial management of these patients.

Sensing danger: toll-like receptors and outcome in allogeneic hematopoietic stem cell transplantation

Pattern recognition receptors (PRRs) such as Toll-like receptors (TLRs) play key roles in initiating innate and adaptive immune responses. Based mainly on animal studies there is growing evidence to suggest that TLRs are involved in the development of chemotherapy-induced mucositis and in the propagation of graft versus host reactions as well as graft versus tumor effects in allogeneic hematopoietic stem cell transplantation (HSCT). In this review we discuss these findings along with the emerging, although still preliminary, clinical evidence, that points to a role of PRRs in determining the outcome of HSCT and new therapeutic perspectives that may be related to this development.

Bloodstream infections caused by Klebsiella pneumoniae in onco-hematological patients: clinical impact of carbapenem resistance in a multicentre prospective survey

The aim of this study was to identify risk factors for mortality in patients suffering from hematological malignancies (HMs) with bloodstream infections (BSIs) caused by Klebsiella pneumoniae (KP). We conducted a prospective cohort study on KP BSI in 13 Italian hematological units participating in the HEMABIS registry-SEIFEM group. The outcome measured was death within 21 days of BSI onset. Survivor and non-survivor subgroups were compared and Cox regression analysis was conducted to identify independent predictors of mortality. A total of 278 episodes of KP BSI were included in the study between January 2010 and June 2014. We found that 161 (57.9%) KP isolates were carbapenem resistant (CRKP). The overall 21-day mortality rate was 36.3%. It was significantly higher for patients with CRKP BSI (84/161, 52.2%) than for those with BSI caused by carbapenem susceptible KP (CSKP) (17/117, 14.5%; P < 0.001). Septic shock (HR 3.86), acute respiratory failure (HR 2.32), inadequate initial antimicrobial therapy (HR 1.87) and carbapenem resistance by KP isolates (HR 1.85) were independently associated with mortality. A subanalysis was conducted in only 149 patients with CRKP BSI who had received ≥48 hr of adequate antibiotic therapy, and combination therapy was independently associated with survival (HR 0.32). Our study shows that in recent years carbapenem resistance has dramatically increased in HM patients with KP BSI in Italy and is associated with a worse outcome. The optimal management of such infections and the definition of new empirical/targeted antimicrobial strategies in HM patients can still be considered unmet clinical needs. Am. J. Hematol. 91:1076-1081, 2016. © 2016 Wiley Periodicals, Inc.

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.

The growing threat of multidrug-resistant Gram-negative infections in patients with hematologic malignancies

Prolonged neutropenia and chemotherapy-induced mucositis render patients with hematologic malignancies highly vulnerable to Gram-negative bacteremia. Unfortunately, multidrug-resistant (MDR) Gram-negative bacteria are increasingly encountered globally, and current guidelines for empirical antibiotic coverage in these patients may not adequately treat these bacteria. This expansion of resistance, coupled with traditional culturing techniques requiring 2-4 days for bacterial identification and antimicrobial susceptibility results, have grave implications for these immunocompromised hosts. This review characterizes the epidemiology, risk factors, resistance mechanisms, recommended treatments, and outcomes of the MDR Gram-negative bacteria that commonly cause infections in patients with hematologic malignancies. We also examine the infection prevention strategies in hematology patients, such as infection control practices, antimicrobial stewardship, and targeted decolonization. Finally, we assess the strategies to improve outcomes of the infected patients, including gastrointestinal screening to guide empirical antibiotic therapy, new rapid diagnostic tools for expeditious identification of MDR pathogens, and use of two new antimicrobial agents, ceftolozane/tazobactam and ceftazidime/avibactam.

Overview of Infections in the Immunocompromised Host

Understanding the components of the immune system that contribute to host defense against infection is key to recognizing infections that are more likely to occur in an immunocompromised patient. In this review, we discuss the integrated system of physical barriers and of innate and adaptive immunity that contributes to host defense. Specific defects in the components of this system that predispose to particular infections are presented. This is followed by a review of primary immunodeficiency diseases and secondary immunodeficiencies, the latter of which develop because of a specific illness or condition or are treatment-related. The effects of treatment for neoplasia, autoimmune diseases, solid organ and stem cell transplants on host defenses are reviewed and associated with susceptibility to particular infections. In conclusion, an approach to laboratory screening for a suspected immunodeficiency is presented. Knowledge of which host defects predispose to specific infections allows clinicians to prevent, diagnose, and manage infections in their immunocompromised patients most effectively.

Retrospective observational study to assess the clinical management and outcomes of hospitalised patients with complicated urinary tract infection in countries with high prevalence of multidrug resistant Gram-negative bacteria (RESCUING)

INTRODUCTION

The emergence of multidrug resistant (MDR) Gram-negative bacteria (GNB), including carbapenemase-producing strains, has become a major therapeutic challenge. These MDR isolates are often involved in complicated urinary tract infection (cUTI), and are associated with poor clinical outcomes. The study has been designed to gain insight into the epidemiology, clinical management, outcome and healthcare cost of patients with cUTI, especially in countries with high prevalence of MDR GNB.

METHODS AND ANALYSIS

This multinational and multicentre observational, retrospective study will identify cases from 1 January 2013 to 31 December 2014 in order to collect data on patients with cUTI as a cause of hospital admission, and patients who develop cUTI during their hospital stay. The primary end point will be treatment failure defined as the presence of any of the following criteria: (1) signs or symptoms of cUTI present at diagnosis that have not improved by days 5-7 with appropriate antibiotic therapy, (2) new cUTI-related symptoms that have developed within 30 days of diagnosis, (3) urine culture taken within 30 days of diagnosis, either during or after completion of therapy, that grows ≥10(4) colony-forming unit/mL of the original pathogen and (4) death irrespective of cause within 30 days of the cUTI diagnosis.

SAMPLE SIZE

1000 patients afford a power of 0.83 (α=0.05) to detect an absolute difference of 10% in the treatment failure rate between MDR bacteria and other pathogens. This should allow for the introduction of about 20 independent risk factors (or their interaction) in a logistic regression model looking at risk factors for failure.

ETHICS AND DISSEMINATION

Approval will be sought from all relevant Research Ethics Committees. Publication of this study will be considered as a joint publication by the participating investigator leads, and will follow the recommendations of the International Committee of Medical Journal Editors (ICMJE).

TRIAL REGISTRATION NUMBER

NCT02641015; Pre-results.

Bloodstream infections in neutropenic cancer patients: A practical update

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

Ciprofloxacin prophylaxis delays initiation of broad-spectrum antibiotic therapy and reduces the overall use of antimicrobial agents during induction therapy for acute leukaemia: A single-centre study

BACKGROUND

Due to an outbreak of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae, the routine use of fluoroquinolone prophylaxis was questioned. As a result, this study was conducted with the aim to evaluate the impact of ciprofloxacin-prophylaxis on the use of broad-spectrum antibioctics and anti-mycotics.

METHODS

A cohort of 139 consecutive patients with acute leukaemia treated with remission-inducing induction chemotherapy between 2004-2012 at the Department of Haematology in Uppsala University Hospital was analysed.

RESULTS

Fifty-three patients (38%) received broad-spectrum antibiotics at the initiation of chemotherapy and were not eligible for prophylaxis. Of the remaining patients, the initiation of broad-spectrum antibiotics was delayed by 3 days in those receiving ciprofloxacin prophylaxis (n = 47) compared with those receiving no prophylaxis (n = 39). The median duration of systemic antibiotic treatment was 6 days shorter in patients receiving ciprofloxacin prophylaxis (12 vs 18 days; p = 0.0005) and the cumulative (total) median days on systemic antibiotic treatment was shortened by 8 days (15 vs 23 days, p = 0.0008). Piperacillin/tazobactam (p = 0.02), carbapenems (p = 0.05) and empiric broad-spectrum antifungals (p < 0.01) were used significantly less often when ciprofloxacin prophylaxis was given.

CONCLUSIONS

Ciprofloxacin prophylaxis delayed empiric therapy by 3 days and reduced overall antibiotic use in this study. These benefits must be evaluated vs the risks of development of resistant bacterial strains, making fluoroquinolone prophylaxis an open question for debate.

Bloodstream infections in patients with solid tumors

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

Approach to Non-Neutropenic Fever in Pediatric Oncology Patients-A Single Institution Study

BACKGROUND

Pediatric oncology patients with fever, even when not neutropenic, are known to be at an increased risk of bloodstream infections. However, there are no standard guidelines for management of fever in non-neutropenic patients, resulting in variability in practice across institutions.

PROCEDURE

We retrospectively analyzed the clinical characteristics, management, and outcome of all febrile non-neutropenic episodes in pediatric oncology patients at a single institution over the two-year period 2011-2012, to identify predictors of bloodstream infections. We assessed the efficacy of a uniform approach to outpatient management of a defined subset of patients at low risk of invasive infections.

RESULTS

A total of 254 episodes in 83 patients were identified. All patients had implanted central venous catheters (port). Sixty-two episodes (24%) were triaged as high-risk and admitted for inpatient management; five (8%) had positive blood cultures. The remaining 192 episodes were triaged as low risk and managed with once daily outpatient intravenous ceftriaxone; three (1.6%) were associated with bacteremia, and 10% required eventual inpatient management. Of all the factors analyzed, only signs of sepsis (lethargy, chills, hypotension) were associated with positive bloodstream infection.

CONCLUSIONS

Treatment of a defined subset of patients with outpatient intravenous ceftriaxone was safe and effective. Signs of sepsis were the only factor significantly associated with bloodstream infection. This study provides a baseline for future prospective studies assessing the safety of withholding antibiotics in this subset of patients.