Stenotrophomonas maltophilia Infections: A Systematic Review and Meta-Analysis of Comparative Efficacy of Available Treatments, with Critical Assessment of Novel Therapeutic Options

Stenotrophomonas maltophilia (SM) represents a challenging pathogen due to its resistance profile. A systematic review of the available evidence was conducted to evaluate the best treatment of SM infections to date, focusing on trimethoprim/sulfamethoxazole (TMP/SMX), fluoroquinolones (FQs), and tetracycline derivatives (TDs). Materials: PubMed/MEDLINE and Embase were searched from inception to 30 November 2022. The primary outcome was all-cause mortality. Secondary outcomes included clinical failure, adverse events, and length of stay. A random effects meta-analysis was performed. This study was registered with PROSPERO (CRD42022321893). Results: Twenty-four studies, all retrospective, were included. A significant difference in terms of overall mortality was observed when comparing as a monotherapy TMP/SMX versus FQs (odds ratio (OR) 1.46, 95% confidence interval (CI) 1.15-1.86, I-2 = 33%; 11 studies, 2407 patients). The prediction interval (PI) did not touch the no effect line (1.06-1.93), but the results were not robust for the unmeasured confounding (E-value for point estimate of 1.71). When comparing TMP/SMX with TDs, the former showed an association with higher mortality but not significant and with a wide PI (OR 1.95, 95% CI 0.79-4.82, PI 0.01-685.99, I-2 = 0%; 3 studies, 346 patients). Monotherapies in general exerted a protective effect against death opposed to the combination regimens but were not significant (OR 0.71, 95% CI 0.41-1.22, PI 0.16-3.08, I-2 = 0%; 4 studies, 438 patients). Conclusions: Against SM infections, FQs and, possibly, TDs seem to be reasonable alternative choices to TMP/SMX. Data from clinical trials are urgently needed to better inform therapeutic choices in this setting by also taking into account newer agents

Meropenem/Vaborbactam Plus Aztreonam as a Possible Treatment Strategy for Bloodstream Infections Caused by Ceftazidime/Avibactam-Resistant <i>Klebsiella pneumoniae</i>: A Retrospective Case Series and Literature Review

Objectives: The aim of this study was to describe our experience of a combination treatment including meropenem/vaborbactam (M/V) plus aztreonam (ATM) for bloodstream infections (BSIs) due to ceftazidime/avibactam-resistant Klebsiella pneumoniae (CAZ/AVI-R-Kp), for which gene typing was not available at the time the blood culture (BC) results were obtained. Methods: Between 20 July and 22 August 2021, in our hospital laboratory, the molecular test for carbapenemase gene typing was not available. All Gram-negative bloodstream infections were recorded, and characteristics of patients were analysed. Among them, three patients had positive BCs for CAZ/AVI-R-Kp, and the empirical therapy was switched to M/V plus ATM pending phenotypic testing of sensitivity to M/V. Therapy was subsequently targeted on the basis of the results of this test. Results: KPC and NDM represent the most prevalent carbapenemases in our polyclinic. Three patients with CAZ/AVI-R-Kp sepsis were treated with M/V plus ATM not knowing the carbapenemase gene. Two had an NDM-Kp infection for which, upon obtaining the result of sensitivity to M/V, combination therapy was maintained. The third had KPC-Kp infection for which ATM was discontinued, after the acquisition of an antibiogram reporting full sensitivity to M/V (MIC = 0.25 mg/L). One patient with NDM-Kp infection died due to complications of the underlying disease for which he was hospitalised. Conclusions: Meropenem/vaborbactam plus ATM and subsequent de-escalation could represent a possible therapeutic strategy in severe CAZ/AVI-R-Kp infections when carbapenemase gene typing is not rapidly available

Determinação da solução ótima do problema de fluxo de potência ótimo via análise de sensibilidade

Neste trabalho propomos uma abordagem para a resolução do problema de Fluxo de Potência Ótimo (FPO) perturbado. A metodologia consiste na utilização de análise de sensibilidade para estimar novas soluções depois de ocorridas algumas perturbações no problema a partir de uma solução ótima obtida via um programa de FPO. Estas perturbações podem ser variações de carga em uma ou mais barras do sistema. A técnica de análise de sensibilidade é baseada nas informações de segunda ordem e nas condições de Karush-Kuhn-Tucker (KKT). A obtenção da solução após ocorrerem perturbações no sistema é direta e não necessita de parâmetros iniciais e de correção como os de penalidade e de barreira, utilizados nos programas de FPO convencionais. Os resultados numéricos apresentados evidenciam o potencial desta metodologia para resolução do problema de FPO para pequenas perturbações.We propose in this work an approach for solving the perturbated Optimal Power Flow (OPF) problem. The methodology consists in the use of sensitivity analysis to estimate new solutions after occurring some perturbations in the problem starting from optimal solution obtained via an OPF program. These perturbations consist in loading variations in some busses of the system. The sensitivity analysis technique is based on the information of second order and in the Karush-Kuhn-Tucker conditions. The obtaining of the solutions after the occurrence of perturbations in the system is direct and it doesn't need initial parameters and correction parameters as other methods like penalty and barrier used in the conventional OPF programs need. The numerical results demonstrate the potential of this methodology for the solution of the perturbated OPF problem.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Safety and effectiveness of fifth generation cephalosporins for the treatment of methicillin-resistant staphylococcus aureus bloodstream infections: a narrative review exploring past, present, and future

IntroductionMethicillin-resistant Staphylococcus aureus (MRSA) bloodstream infection (BSI) is a major issue in healthcare, since it is often associated with endocarditis or deep site foci. Relevant morbidity and mortality associated with MRSA-BSIs forced the development of new antibiotic strategies; in particular, this review will focus the attention on fifth-generation cephalosporins (ceftaroline/ceftobiprole), that are the only ss-lactams active against MRSA.Areas coveredThe review discusses the available randomized controlled trials and real-world observational studies conducted on safety and effectiveness of ceftaroline/ceftobiprole for the treatment of MRSA-BSIs. Finally, a proposal of MRSA-BSI treatment flowchart, based on fifth-generation cephalosporins, is described.Expert opinionThe use of anti-MRSA cephalosporins is an acceptable choice either in monotherapy or combination therapy for the treatment of MRSA-BSIs due to their relevant effectiveness and safety. Particularly, their use may be advisable in combination therapy in case of severe infections (including endocarditis or persistent bacteriemia) or in monotherapy in subjects at higher risk of drugs-induced toxicity with older regimens. On the contrary, caution should be taken in case of suspected/ascertained central nervous system infections due to inconsistent data regarding penetration of these drugs in cerebrospinal fluid and brain tissues

Thoracic aorta graft infection by avibactam-resistant KPC-producing K. pneumoniae treated with meropenem/vaborbactam: a case report and literature review

Meropenem/vaborbactam (M/V) is a new carbapenem-carbapenemase inhibitor combination drug active against extensively drug resistant Gram-negative pathogens. Studies about its efficacy and place in therapy are limited in "real-life" and no data are available for deep site infections, like vascular graft infections. We present a case of a patient successfully treated with M/V for a thoracic aorta graft infection, placed for a traumatic penetrating aortic ulcer, due to an extensively KPC-producing Klebsiella pneumoniae resistant to ceftazidime/ avibactam. Furthermore, we conducted a systematic literature review concerning vascular graft infections caused by carbapenem-resistant Klebsiella pneumoniae and the papers published until now about the use of M/V for the treatment of ceftazidime/avibactam-resistant K. pneumoniae. Meropenem/vaborbactam is a promising antibiotic for difficult-to-treat Gram-negative bacteria with limited therapeutic options. Only few reports have been published and more studies are needed to assess which is the best place in therapy of M/V

Cefiderocol-Based Combination Therapy for “Difficult-to-Treat” Gram-Negative Severe Infections: Real-Life Case Series and Future Perspectives

Cefiderocol is a new cephalosporin displaying against extensively resistant (XDR) Gram-negative bacteria. We report our experience with cefiderocol-based combination therapies as “rescue” treatments in immunocompromised or critically ill patients or in patients with post-surgical infections who had failed previous regimens. A total of 13 patients were treated from 1 September 2020 to 31 March 2021. In total, 5/13 (38%) patients were classified as critically ill, due to severe COVID-19 lung failure; 4/13 (31%) patients had post-surgical infections and 4/13 (31%) had severe infections in immunocompromised subjects due to solid organ transplantation (2/4) or hematological malignancy (2/4). Overall, 10/13 infections were caused by carbapenem-resistant Acinetobacter baumannii, one by KPC-positive ceftazidime/avibactam-resistant Klebsiella pneumonia and two by Pseudomonas aeruginosa XDR. Based on clinical, microbiological and hematobiochemical evaluation, cefiderocol was associated with different companion drugs, particularly with fosfomycin, high-dose tigecycline and/or colistin. Microbiological eradication was achieved in all cases and the 30-day survival rate was 10/13; two patients died due to SARS-CoV-2 lung failure, whereas one death was attributed to subsequent infections. No recurrent infections within 30 days were reported. Finally, we hereby discuss the therapeutic potential of cefiderocol and the possible place in the therapy of this novel drug

Current therapies for chronic lymphocytic leukemia: risk and prophylaxis strategies for secondary/opportunistic infections

Introduction: Currently, the implementation of new therapeutic options for treatment of chronic lymphocytic leukemia (CLL) considerably improved the outcome of this disease. However, patients affected by CLL are at higher risk for infections, due to the state of immunosuppression related to hematologic disease and therapies. Consequently, anti-infective prophylaxis should be properly managed, according to risk factors for opportunistic infection, related to antineoplastic drugs and characteristics of patients.Areas covered: This review aims to summarize current knowledge on secondary/opportunistic infections during CLL treatment, including chemo-immunotherapies, Bruton Tyrosine Kinase inhibitors, idelalisib and venetoclax. In addition, possible schemes of prophylaxis are provided.Expert opinion: The establishment of a multidisciplinary team including hematologist and infectious diseases specialist is pivotal for the best management of anti-infective prophylaxis and prevention of new onset infections

Incidence and predictors of infections in patients with advanced non‐small cell lung cancer treated with checkpoint inhibitor immunotherapies: A monocentric retrospective cohort study

Immune checkpoint inhibitors (ICIs) represent the cornerstone of the current treatment of non-small cell lung cancer (NSCLC). However, the occurrence of concomitant infections might hamper success. All consecutive patients with advanced NSCLC who started ICIs as a first- or second-line therapy from January 1, 2017 to June 30, 2020 were retrospectively evaluated. The occurrence of infectious events during ICIs was correlated with clinical characteristics, including previous Cytotoxic Chemotherapy (CC), occurrence of immune-related-adverse-events (irAEs). A total of 211 patients were included, 46 (22%) females, with a median (q1-q3) age of 69 (62-76) years. Overall, 85 patients (40%) received ICIs as a first treatment line and 126 (60%) as a second line; 40 patients (19%) had at least one infection during ICIs, and 17 (8%) more than one. Notably, autoimmune diseases (P &lt; .005), neutropenia (P = .001) or infections during previous CC (P = .001), irAEs (P = .006), or steroid therapy for irAEs (P &lt; .001) were associated with infection development. By multivariate Cox-regression, autoimmune diseases (aHR = 6.27; 95%CI = 2.38-16.48; P &lt; .001) and steroid therapy for irAEs (aHR = 2.65; 95%CI = 1.27-5.52; P &lt; .009) were associated with a higher risk of infection during ICIs. Interestingly, autoimmune diseases were confirmed as risk factors in patients treated with ICIs as a first line, while previous infections were the only independent predictor of infections in patients treated with ICIs as a second line. Patients with NSCLC treated with ICIs with concurrent autoimmune disease, receiving steroid therapy for management of irAEs, or having a history of previous infections during CC should be actively monitored for the risk of developing infectious complications