Clinical Predictive Model of Multidrug Resistance in Neutropenic Cancer Patients with Bloodstream Infection Due to Pseudomonas aeruginosa.

We aimed to assess the rate and predictive factors of bloodstream infection (BSI) due to multidrug-resistant (MDR) Pseudomonas aeruginosa in neutropenic cancer patients. We performed a multicenter, retrospective cohort study including oncohematological neutropenic patients with BSI due to P. aeruginosa conducted across 34 centers in 12 countries from January 2006 to May 2018. A mixed logistic regression model was used to estimate a model to predict the multidrug resistance of the causative pathogens. Of a total of 1,217 episodes of BSI due to P. aeruginosa, 309 episodes (25.4%) were caused by MDR strains. The rate of multidrug resistance increased significantly over the study period (P = 0.033). Predictors of MDR P. aeruginosa BSI were prior therapy with piperacillin-tazobactam (odds ratio [OR], 3.48; 95% confidence interval [CI], 2.29 to 5.30), prior antipseudomonal carbapenem use (OR, 2.53; 95% CI, 1.65 to 3.87), fluoroquinolone prophylaxis (OR, 2.99; 95% CI, 1.92 to 4.64), underlying hematological disease (OR, 2.09; 95% CI, 1.26 to 3.44), and the presence of a urinary catheter (OR, 2.54; 95% CI, 1.65 to 3.91), whereas older age (OR, 0.98; 95% CI, 0.97 to 0.99) was found to be protective. Our prediction model achieves good discrimination and calibration, thereby identifying neutropenic patients at higher risk of BSI due to MDR P. aeruginosa The application of this model using a web-based calculator may be a simple strategy to identify high-risk patients who may benefit from the early administration of broad-spectrum antibiotic coverage against MDR strains according to the local susceptibility patterns, thus avoiding the use of broad-spectrum antibiotics in patients at a low risk of resistance development.

Enterococcal bloodstream infection. Design and validation of a mortality prediction rule.

BACKGROUND: To develop a prediction rule to describe the risk of death as a result of enterococcal bloodstream infection. METHODS: A prediction rule was developed by analysing data collected from 122 patients diagnosed with enterococcal BSI admitted to the Clínica Universidad de Navarra (Pamplona, Spain); and validated by confirming its accuracy with the data of an external population (Hospital del Mar, Barcelona). RESULTS: According to this model, independent significant predictors for the risk of death were being diabetic, have received appropriate treatment, severe prognosis of the underlying diseases, have renal failure, received solid organ transplant, malignancy, source of the bloodstream infection and be immunosuppressed. The prediction rule showed a very good calibration (Hosmer-Lemeshow statistic, P = 0.93) and discrimination for both training and testing sets (area under ROC curve = 0.84 and 0.83 respectively). CONCLUSIONS: The predictive rule was able to predict risk of death as a result of enterococcal bloodstream infection as well as to identify patients, who being below the threshold value, will have a low risk of death with a negative predictive value of 96%.

Antifungal prophylaxis with anidulafungin to minimize drug interactions with an antiepileptic treatment in a hematopoietic stem cell transplant recipient.

WHAT IS KNOWN AND OBJECTIVE: Invasive fungal infections are a major cause of morbidity and mortality after hematopoietic stem cell transplantation (HSCT). This provides a clear rationale for antifungal prophylaxis in this population. A concern is the potential for drug interactions, given that most of antifungals are metabolized through the P450 cytochrome system. CASE SUMMARY: We present a case of a 33-year-old woman, with a past history of high-risk epilepsy, who underwent allogeneic HSCT for a myelodysplastic syndrome. Anidulafungin was successfully used as antifungal prophylaxis to minimize drug interactions with her antiepileptic treatment. WHAT IS NEW AND CONCLUSION: This is the first reported case of antifungal prophylaxis with this echinocandin in HSCT. Anidulafungin may be an option in transplant recipients with multiple risk factors for drug interactions.

Linezolid-induced lactic acidosis in two liver transplant patients with the mitochondrial DNA A2706G polymorphism.

Mitochondrial toxicity has been recently suggested to be the underlying mechanism of long-term linezolid-associated toxicity in patients with 16S rRNA genetic polymorphisms. Here, we report for the first time two cases of lactic acidosis due to long-term linezolid exposure in liver transplant recipients who presented an A2706G mitochondrial DNA polymorphism.

Smart central venous port for early detection of bacterial biofilm related infections.

Central venous catheters (CVC) are commonly used in clinical practice to improve a patient's quality of life. Unfortunately, there is an intrinsic risk of acquiring an infection related to microbial biofilm formation inside the catheter lumen. It has been estimated that 80 % of all human bacterial infections are biofilm-associated. Additionally, 50 % of all nosocomial infections are associated with indwelling devices. Bloodstream infections account for 30-40 % of all cases of severe sepsis and septic shock, and are major causes of morbidity and mortality. Diagnosis of bloodstream infections must be performed promptly so that adequate antimicrobial therapy can be started and patient outcome improved. An ideal diagnostic technology would identify the infecting organism(s) in a timely manner, so that appropriate pathogen-driven therapy could begin promptly. Unfortunately, despite the essential information it provides, blood culture, the gold standard, largely fails in this purpose because time is lost waiting for bacterial or fungal growth. This work presents a new design of a venous access port that allows the monitoring of the inner reservoir surface by means of an impedimetric biosensor. An ad-hoc electronic system was designed to manage the sensor and to allow communication with the external receiver. Historic data recorded and stored in the device was used as the reference value for the detection of bacterial biofilm. The RF communication system sends an alarm signal to the external receiver when a microbial colonization of the port occurs. The successful in vitro analysis of the biosensor, the electronics and the antenna of the new indwelling device prototype are shown. The experimental conditions were selected in each case as the closest to the clinical working conditions for the smart central venous catheter (SCVC) testing. The results of this work allow a new generation of this kind of device that could potentially provide more efficient treatments for catheter-related infections.

Vascular catheter-related infections: an endemic disease in healthcare institutions. An opinion paper of the Spanish Society of Cardiovascular Infections (SEICAV).

Catheter-related infections (CRI) are a serious healthcare problem due to their potential to cause serious complications, including bacteraemia or infective endocarditis, and to increase patient morbidity and mortality. In addition, these in fections significantly prolong hospital stay and cost. Preventing CRI is crucial and is considered a criterion for quality and safety in healthcare. For these reasons, the Spanish Society of Cardiovascular Infections (SEICAV) has considered it pertinent to review this topic, with experts in different areas including clinical microbiologists, infectious disease specialists, surgeons and nurses. The data were presented at a session held at the Ramón Areces Foundation, which was organised in the form of specific questions grouped into three round tables. The first panel analysed the scale of the problem including epidemiological, clinical and diagnostic aspects; the second panel addressed advances in the treatment of CRI; and the third panel reviewed developments in the prevention of CRI. The recorded session is available on the Areces Foundation website and we believe it maybe of interest not only to health professionals, but also to any non-expert citizen interested in the subject.

Present and future of resistance in Pseudomonas aeruginosa: implications for treatment.

Pseudomonas aeruginosa is a pathogen that has a high propensity to develop antibiotic resistance, and the emergence of multidrug-resistant strains is a major concern for global health. The mortality rate associated with infections caused by this microorganism is significant, especially those caused by multidrug-resistant strains. The antibiotics used to treat these infections include quinolones, aminoglycosides, colistin, and ß-lactams. However, novel combinations of ß-lactams-ß-lactamase inhibitors and cefiderocol offer advantages over other members of their family due to their better activity against certain resistance mechanisms. Selecting the appropriate empiric antibiotic treatment requires consideration of the patient's clinical entity, comorbidities, and risk factors for multidrug-resistant pathogen infections, and local epidemiological data. Optimizing antibiotic pharmacokinetics, controlling the source of infection, and appropriate collection of samples are crucial for successful treatment. In the future, the development of alternative treatments and strategies, such as antimicrobial peptides, new antibiotics, phage therapy, vaccines, and colonization control, holds great promise for the management of P. aeruginosa infections.

Impact of the COVID-19 pandemic on the diagnosis and treatment of onco-hematologic patients: a discussion paper.

We do not know the precise figure for solid organ tumors diagnosed each year in Spain and it is therefore difficult to calculate whether there has been a decrease in cancer diagnoses as a consequence of the pandemic. Some indirect data suggest that the pandemic has worsened the stage at which some non-hematological neoplasms are diagnosed. Despite the lack of robust evidence, oncology patients seem more likely to have a poor outcome when they contract COVID-19. The antibody response to infection in cancer patients will be fundamentally conditioned by the type of neoplasia present, the treatment received and the time of its administration. In patients with hematological malignancies, the incidence of infection is probably similar or lower than in the general population, due to the better protective measures adopted by the patients and their environment. The severity and mortality of COVID-19 in patients with hematologic malignancies is clearly higher than the general population. Since the immune response to vaccination in hematologic patients is generally worse than in comparable populations, alternative methods of prevention must be established in these patients, as well as actions for earlier diagnosis and treatment. Campaigns for the early diagnosis of malignant neoplasms must be urgently resumed, post-COVID manifestations should be monitored, collaboration with patient associations is indisputable and it is urgent to draw the right conclusions to improve our preparedness to fight against possible future catastrophes.

Iliac bone Candida albicans osteomyelitis in a patient with iliac crest bone autograft: a case report and review of the literature.

Candida osteomyelitis is a well recognized but infrequent entity. We describe an interesting case of iliac bone C. albicans osteomyelitis as a result of a surgical trauma of an iliac bone for the auto-grafting of a fracture in the lumbar spine. The peri-operative acquisition of Candida was by the inoculation of a yeast colonizing the skin. Remarkably, several risk factors described for Candida infection and candidemia were absent. The patient also presented with a local fistula. The iliac crest was the only bone affected and local pain was the only symptom present in our case. Diagnosis was made by multiple-specimen biopsy obtained by surgery. Treatment with fluconazole was successful.

Daptomycin lock therapy for grampositive long-term catheter-related bloodstream infections.

INTRODUCTION: To evaluate the efficacy of Daptomycin (DPT) lock therapy in the treatment of Grampositive long-term catheter-related bloodstream infections (LT-CRBI). PATIENTS AND METHODS: A retrospective review of all patients receiving DPT lock therapy for the treatment of LT-CRBI from December 2009 to May 2010 was conducted. The primary endpoint used in this study was failure to cure the episode of LT-CRBI. Cure was defined as fever disappearance, negative blood cultures within 1 month after the end of treatment, and catheter salvage. RESULTS: Thirteen subjects (seven men, mean age 62 years) were evaluated. There were six Staphylococcus epidermidis, two Staphylococcus hominis, one Staphylococcus haemolyticus, two Enterococcus faecalis and two polymicrobial (S. epidermidis and S. hominis) bloodstream infections. DPT lock therapy was administered for a mean of 14 days (interquartilic range 10-14). Intravenous DPT was administered in nine patients for a mean of 10 days (interquartilic range 5-11). Clinical cure and blood culture sterilisation occurred in 11 of 13 patients (85%). Two patients had fever during treatment and catheters were removed. Median length of follow-up in patients with therapeutic success was 67 days (interquartilic range 14-88). CONCLUSION: DPT lock therapy demonstrated good in vivo efficacy in LT-CRBI caused by coagulase negative staphylococci and Enterococcus species.

Respiratory infections in Coronavirus disease 2019.

In the last two years, the capacity of our hospitals has clearly been overwhelmed due to the COVID-19 pandemic The patient who comes to the hospital with a respiratory coinfection does not have the same characteristics as the patient who suffers a superinfection while hospitalized. The number of secondary infections increase proportionally to the severity of the patient's disease. Besides, pathogens that cause a coinfection are clearly differentiated from the pathogens that cause a superinfection. However, in patients subjected to airway manipulation, superinfections by distinct pathogens can occur. Seventy five percent of patients admitted worldwide with COVID-19 (especially during the first two waves of the pandemic) received some form of antibiotic treatment during admission. In this context, it is essential to develop and implement algorithms that allow us to define the predictors in each individual case for the development of a superinfection.

Treatment of infections caused by carbapenemase-producing Enterobacterales.

Antibiotic resistance is one of the main menaces to public and individual health worldwide. In the last two decades, an increase in the detection of carbapenem-resistant Enterobacterales has been reported. The treatment of infections caused by these strains is a therapeutic challenge. The use of carbapenems may be beneficial depending on MIC value and source of infection. New drugs, with different activity against the different classes of carbapenemases, are developed showing significant benefits.

A systematic literature review and expert consensus on risk factors associated to infection progression in adult patients with respiratory tract or rectal colonisation by carbapenem-resistant Gram-negative bacteria.

OBJECTIVE: Risk factors (RFs) associated with infection progression in patients already colonised by carbapenem-resistant Gram-negative bacteria (CRGNB) have been addressed in few and disperse works. The aim of this study is to identify the relevant RFs associated to infection progression in patients with respiratory tract or rectal colonisation. METHODS: A systematic literature review was developed to identify RFs associated with infection progression in patients with CRGNB respiratory tract or rectal colonisation. Identified RFs were then evaluated and discussed by the expert panel to identify those that are relevant according to the evidence and expert's experience. RESULTS: A total of 8 articles were included for the CRGNB respiratory tract colonisation and 21 for CRGNB rectal colonisation, identifying 19 RFs associated with pneumonia development and 44 RFs associated with infection progression, respectively. After discussion, the experts agreed on 13 RFs to be associated with pneumonia development after respiratory tract CRGNB colonisation and 33 RFs to be associated with infection progression after rectal CRGNB colonisation. Respiratory tract and rectal colonisation, previous stay in the ICU and longer stay in the ICU were classified as relevant RF independently of the pathogen and site of colonisation. Previous exposure to antibiotic therapy or previous carbapenem use were also common relevant RF for patients with CRGNB respiratory tract and rectal colonisation. CONCLUSIONS: The results of this study may contribute to the early identification of CRGNB colonized patients at higher risk of infection development, favouring time-to-effective therapy and improving health outcomes.

Respiratory co-and superinfections in COVID-19.

There are few publications on the impact of coinfection and superinfection in patients with COVID-19. Patients with higher severity are much more prone to secondary bacterial, fungal or viral infections. The overuse of antimicrobials in many viral infections (including SARS-CoV-2 infections) undoubtedly contributes to the current antimicrobial resistance crisis. In the context of COVID-19, we are witnessing an increase in multidrug-resistant bacterial infections in our hospitals. The heterogeneity of published studies makes it critical to perform more large-scale studies to better understand the pathogenesis of coinfections or superinfections in the COVID-19 patient.

In vitro activity of imipenem/relebactam against Gram-negative clinical isolates in two Spanish tertiary hospitals.

OBJECTIVE: The aim of this study was to analyze the activity of the imipenem-relebactam combination (IMI/REL) against a collection of multidrug-resist Enterobacterales, Pseudomonas aeruginosa and Acinetobacter baumannii clinical isolates. METHODS: The study was conducted in two tertiary hospitals in Spain and included 192 clinical isolates of these 3 genera (139 resistant and 53 susceptible to IMI). The MICs for IMI with and without REL (at a fixed concentration of 4 mg/L) were determined by a standard broth microdilution method according to international recommendations. RESULTS: All IMI-susceptible E. coli strains were also susceptible to IMI/REL. Enterobacterales resistant to IMI due to the production of carbapenemases, the MIC50 and MIC90 decreased from 64/256 with IMI to 8/64 mg/L with IMI/REL. This high activity was principally detected among isolates with KPC enzymes. Enterobacterales with class B carbapenemases, P. aeruginosa carrying VIM carbapenemase and A. baumannii strains showed no changes on IMI MIC50 or MIC90 after adding REL. Among P. aeruginosa strains without carbapenemase the MIC for IMI/REL was reduced between 1 to 5 dilutions. CONCLUSIONS: IMI/REL showed high activity against the strains that carry Klebsiella pneumoniae carbapenemase (KPC) and against carbapenem-resistant P. aeruginosa unrelated to the VIM enzyme, mainly AmpC beta lactamase associated with impermeability. Against strains carrying oxacillinase 48 (OXA-48) associated with extended-spectrum beta-lactamase (ESBL), IMI/REL presented activity only slightly better than IMI and had no beneficial effect superior to IMI against A. baumannii.

[A systematic review and expert's analysis of risk factors of infections in adults due to carbapenem-resistant Pseudomonas aeruginosa or Acinetobacter baumannii in Spain]. / Revisión sistemática de la literatura y análisis de expertos sobre los factores de riesgo asociados a infecciones causadas por Pseudomonas aeruginosa o Acinetobacter baumannii resistentes a carbapenémicos en pacientes adultos en España.

OBJECTIVE: The aim of the study is to identify risk factors associated to infections caused by carbapenem-resistant Pseudomonas aeruginosa (CRPA) and carbapenem-resistant Acinetobacter baumannii (CRAB) in adult patients through a systematic literature review, classify them according to their importance and provide recommendations by experts in the Spanish context. METHODS: We developed a systematic literature review to identify risk factors associated to CRPA or CRAB infections and they were evaluated and discussed by a multidisciplinary panel of experts. RESULTS: There were included 29 studies for P. aeruginosa and 23 for A. baumannii out of 593 identified through systematic literature review. We identified 38 risk factors for P. aeruginosa and 36 for A. baumannii. After risk factor evaluation by the panel of experts, results for CRPA were: 11 important, 10 slightly important and 15 unimportant risk factors; and for CRAB were: 9 important, 5 slightly important and 19 unimportant risk factors. For both pathogens, previous use of antibiotics and hospitalization were important risk factors. CONCLUSIONS: We could identify the main risk factors associated to CRPA and CRAB through literature review. There is a need for developing additional studies with higher levels of evidence to identify sooner and better infected patients through associated risk factors.

Efficacy of extended infusion of ß-lactam antibiotics for the treatment of febrile neutropenia in haematologic patients: protocol for a randomised, multicentre, open-label, superiority clinical trial (BEATLE).

BACKGROUND: Febrile neutropaenia (FN) is a very common complication in patients with haematological malignancies and is associated with considerable morbidity and mortality. Broad-spectrum antipseudomonal ß-lactam antibiotics (BLA) are routinely used for the treatment of cancer patients with FN. However, the clinical efficacy of BLA may be diminished in these patients because they present with pathophysiological variations that compromise the pharmacokinetic (PK) parameters of these antibiotics. Optimised administration of BLA in prolonged infusions has demonstrated better clinical outcomes in critically ill patients. However, there is a paucity of data on the usefulness of this strategy in patients with FN. The aim of this study is to test the hypothesis that the administration of BLA would be clinically more effective by extended infusion (EI) than by intermittent infusion (II) in haematological patients with FN. METHODS: A randomised, multicentre, open-label, superiority clinical trial will be performed. Patients with haematological malignancies undergoing chemotherapy or haematopoietic stem-cell transplant and who have FN and receive empirical antibiotic therapy with cefepime, piperacillin-tazobactam or meropenem will be randomised (1:1) to receive the antibiotic by EI (during half the time of the dosing interval) in the study group, or by II (30 min) in the control group. The primary endpoint will be clinical efficacy, defined as defervescence without modifying the antibiotic treatment administered within the first 5 days of therapy. The primary endpoint will be analysed in the intention-to-treat population. The secondary endpoints will be pharmacokinetic/pharmacodynamic (PK/PD) target achievement, bacteraemia clearance, decrease in C-reactive protein, overall (30-day) case-fatality rate, adverse events and development of a population PK model of the BLA studied. DISCUSSION: Data on the usefulness of BLA administration in patients with FN are scant. Only three clinical studies addressing this issue have been published thus far, with contradictory results. Moreover, these studies had some methodological flaws that limit the interpretation of their findings. If this randomised, multicentre, phase IV, open-label, superiority clinical trial validates the hypothesis that the administration of BLA is clinically more effective by EI than by II in haematological patients with FN, then the daily routine management of these high-risk patients could be changed to improve their outcomes. TRIAL REGISTRATION: European Clinical Trials Database: EudraCT 2018-001476-37. ClinicalTrials.gov, ID: NCT04233996.

Suppressive antibiotic therapy in prosthetic joint infections: a multicentre cohort study.

OBJECTIVES: The aim was to describe the effectiveness of suppressive antibiotic treatment (SAT) in routine clinical practice when used in situations in which removal of a prosthetic implant is considered essential for the eradication of an infection, and it cannot be performed. METHODS: This was a descriptive retrospective and multicentre cohort study of prosthetic joint infection (PJI) cases managed with SAT. SAT was considered to have failed if a fistula appeared or persisted, if debridement was necessary, if the prosthesis was removed due to persistence of the infection or if uncontrolled symptoms were present. RESULTS: In total, 302 patients were analysed. Two hundred and three of these patients (67.2%) received monotherapy. The most commonly used drugs were tetracyclines (39.7% of patients) (120/302) and cotrimoxazole (35.4% of patients) (107/302). SAT was considered successful in 58.6% (177/302) of the patients (median time administered, 36.5 months; IQR 20.75-59.25). Infection was controlled in 50% of patients at 5 years according to Kaplan-Meier analysis. Resistance development was documented in 15 of 65 (23.1%) of the microbiologically documented cases. SAT failure was associated with age <70 years (sub-hazard ratio (SHR) 1.61, 95% CI 1.1-2.33), aetiology other than Gram-positive cocci (SHR 1.56, 95% CI 1.09-2.27) and location of the prosthesis in the upper limb (SHR 2.4, 95% CI 1.5-3.84). SAT suspension was necessary due to adverse effects in 17 of 302 patients (5.6%). CONCLUSIONS: SAT offers acceptable results for patients with PJI when surgical treatment is not performed or when it fails to eradicate the infection.

Stewardship in sepsis.

Sepsis is the major cause of mortality from any infectious disease worldwide. The goals of antimicrobial stewardship are to achieve optimum clinical outcomes and to ensure cost effectiveness and minimum unintended consequences, including toxic effects, selection of pathogenic organisms, and resistance. The combination of inadequate diagnostic criteria for sepsis with the extraordinary time pressure to provide broad-spectrum antimicrobial therapy is troubling from a stewardship perspective. Use of empirical therapy according to guidelines, de-escalation of therapy, switch from intravenous to oral therapy, therapeutic drug monitoring, use of a list of restricted antibiotics, and bedside consultation can lead to significant benefits for clinical outcomes, adverse events, and costs.

Bioelectric effect and bacterial biofilms. A systematic review.

Bacteria growing in biofilms cause a wide range of human infections. Biofilm bacteria are resistant to antimicrobics at levels 500 to 5,000 times higher than those needed to kill non-biofilm bacteria. In vitro experiments have shown that electric current can enhance the activity of some antimicrobial agents against certain bacteria in biofilms; this has been termed the ''bioelectric effect''. Direct electrical current has already been safely used in humans for fracture healing. Application of direct electric current with antimicrobial chemotherapy in humans could theoretically abrogate the need to remove the device in device-related infections, a procedure associated with substantial morbidity and cost. In this article, we review what has been described in the literature with regards to the bioelectric effect.