High Therapeutic Failure Rates Research Articles

Use of Extracellular Monomeric Ubiquitin as a Therapeutic Option for Major Depressive Disorder.

Major depressive disorder (MDD) is a mood disorder that has become a global health emergency according to the World Health Organization (WHO). It affects 280 million people worldwide and is a leading cause of disability and financial loss. Patients with MDD present immunoendocrine alterations like cortisol resistance and inflammation, which are associated with alterations in neurotransmitter metabolism. There are currently numerous therapeutic options for patients with MDD; however, some studies suggest a high rate of therapeutic failure. There are multiple hypotheses explaining the pathophysiological mechanisms of MDD, in which several systems are involved, including the neuroendocrine and immune systems. In recent years, inflammation has become an important target for the development of new therapeutic options. Extracellular monomeric ubiquitin (emUb) is a molecule that has been shown to have immunomodulatory properties through several mechanisms including cholinergic modulation and the generation of regulatory T cells. In this perspective article, we highlight the influence of the inflammatory response in MDD. In addition, we review and discuss the evidence for the use of emUb contained in Transferon as a concomitant treatment with selective serotonin reuptake inhibitors (SSRIs).

Dendritic Cells as a Therapeutic Strategy in Acute Myeloid Leukemia: Vaccines.

Dendritic cells (DCs) serve as professional antigen-presenting cells (APC) bridging innate and adaptive immunity, playing an essential role in triggering specific cellular and humoral responses against tumor and infectious antigens. Consequently, various DC-based antitumor therapeutic strategies have been developed, particularly vaccines, and have been intensively investigated specifically in the context of acute myeloid leukemia (AML). This hematological malignancy mainly affects the elderly population (those aged over 65), which usually presents a high rate of therapeutic failure and an unfavorable prognosis. In this review, we examine the current state of development and progress of vaccines in AML. The findings evidence the possible administration of DC-based vaccines as an adjuvant treatment in AML following initial therapy. Furthermore, the therapy demonstrates promising outcomes in preventing or delaying tumor relapse and exhibits synergistic effects when combined with other treatments during relapses or disease progression. On the other hand, the remarkable success observed with RNA vaccines for COVID-19, delivered in lipid nanoparticles, has revealed the efficacy and effectiveness of these types of vectors, prompting further exploration and their potential application in AML, as well as other neoplasms, loading them with tumor RNA.

Heteroresistance to colistin in wild-type Klebsiella pneumoniae isolates from clinical origin

ABSTRACT Heteroresistance to colistin can be defined as the presence of resistant subpopulations in an isolate that is susceptible to colistin. The aim of this work was to study heteroresistance in 10 wild-type Klebsiella pneumoniae isolates of clinical origin, to determine the importance of persisters variants and stable mutants in heteroresistance, and to describe genomic changes observed in mutants obtained in population analysis profiling (PAP) assays. Mutations in genes related to colistin resistance (including pmr A, pmr B, pmr C, pmr D, pho P, pho Q, crr A, ccr B, mgr B, ram A, rom A, lax A, lpx C, lpx D, acr A, and acr B) were investigated by whole-genome sequencing with an Illumina platform. Additionally, PCR and Sanger sequencing of the mgr B gene of the selected mutants were also performed. PAP showed that the investigated K. pneumoniae isolates present heteroresistance to colistin, which is related to both the growth of persisters variants and the selection of resistant mutants. A total of 31-point mutations were identified in proteins PhoP, PhoQ, PmrB, and CrrB of which novel mutations were reported in PhoP (E22K, L12Q, and M175K), PhoQ (V24G and L105Q), PmrB (G207D), and CrrB (G183V). MgrB changes included amino acid substitutions (D31N and L19R), deletions (∆C28, ∆C39, ∆Q22, and ∆W6) or the presence of insertion sequences belonging to the IS1 (ISKpn14) and IS5 (ISKpn74) families that inactivated the gene. The results of this study will help to understand the mechanisms involved in colistin heteroresistance among wild-type K. pneumoniae isolates. IMPORTANCE Colistin is one of the last remaining therapeutic options for dealing with Enterobacteriaceae. Unfortunately, heteroresistance to colistin is also rapidly increasing. We described the prevalence of colistin heteroresistance in a variety of wild-type strains of Klebsiella pneumoniae and the evolution of these strains with colistin heteroresistance to a resistant phenotype after colistin exposure and withdrawal. Resistant mutants were characterized at the molecular level, and numerous mutations in genes related to lipopolysaccharide formation were observed. In colistin-treated patients, the evolution of K. pneumoniae heteroresistance to resistance phenotype could lead to higher rates of therapeutic failure.

Long Non-Coding RNAs as Emerging Targets in Lung Cancer.

Long non-coding RNAs (LncRNAs) are mRNA-like molecules that do not encode for proteins and that are longer than 200 nucleotides. LncRNAs play important biological roles in normal cell physiology and organism development. Therefore, deregulation of their activities is involved in disease processes such as cancer. Lung cancer is the leading cause of cancer-related deaths due to late stage at diagnosis, distant metastasis, and high rates of therapeutic failure. LncRNAs are emerging as important molecules in lung cancer for their oncogenic or tumor-suppressive functions. LncRNAs are highly stable in circulation, presenting an opportunity for use as non-invasive and early-stage cancer diagnostic tools. Here, we summarize the latest works providing in vivo evidence available for lncRNAs role in cancer development, therapy-induced resistance, and their potential as biomarkers for diagnosis and prognosis, with a focus on lung cancer. Additionally, we discuss current therapeutic approaches to target lncRNAs. The evidence discussed here strongly suggests that investigation of lncRNAs in lung cancer in addition to protein-coding genes will provide a holistic view of molecular mechanisms of cancer initiation, development, and progression, and could open up a new avenue for cancer treatment.

Prevention of Stress-Induced Depressive-like Behavior by Saffron Extract Is Associated with Modulation of Kynurenine Pathway and Monoamine Neurotransmission.

Depressive disorders are a major public health concern. Despite currently available treatment options, their prevalence steadily increases, and a high rate of therapeutic failure is often reported, together with important antidepressant-related side effects. This highlights the need to improve existing therapeutic strategies, including by using nutritional interventions. In that context, saffron recently received particular attention for its beneficial effects on mood, although the underlying mechanisms are poorly understood. This study investigated in mice the impact of a saffron extract (Safr’Inside™; 6.25 mg/kg, per os) on acute restraint stress (ARS)-induced depressive-like behavior and related neurobiological alterations, by focusing on hypothalamic–pituitary–adrenal axis, inflammation-related metabolic pathways, and monoaminergic systems, all known to be altered by stress and involved in depressive disorder pathophysiology. When given before stress onset, Safr’Inside administration attenuated ARS-induced depressive-like behavior in the forced swim test. Importantly, it concomitantly reversed several stress-induced monoamine dysregulations and modulated the expression of key enzymes of the kynurenine pathway, likely reducing kynurenine-related neurotoxicity. These results show that saffron pretreatment prevents the development of stress-induced depressive symptoms and improves our understanding about the underlying mechanisms, which is a central issue to validate the therapeutic relevance of nutritional interventions with saffron in depressed patients.

Antimicrobial Dosing in Specific Populations and Novel Clinical Methodologies: Obesity.

Obesity and its related comorbidities can negatively influence the outcomes of certain infectious diseases. Specific dosing recommendations are often lacking in the product label for patients with obesity that leads to unclear guidance in practice. Higher rates of therapeutic failure have been reported with some fixed dose antibiotics and pragmatic approaches to dose modification are limited for orally administered agents. For i.v. antimicrobials dosed on weight, alternate body size descriptors (ABSDs) have been used to reduce the risk of overdosing. These ABSDs are mathematical transformations of height and weight that represent fat-free weight and follow the same principles as body surface area (BSA)-based dosing of cancer chemotherapy. However, ABSDs are rarely studied in pivotal phase III studies and so can risk the underdosing of antimicrobials in patients with obesity when incorrectly applied in the real-world setting. Specific case examples are presented to highlight these risks. Although general principles may be considered by clinicians, a universal approach to dose modification in obesity is unlikely. Studies that can better distinguish human body phenotypes may help reduce our reliance on height and weight to define dosing. Simple and complex technologies exist to quantify individual body composition that could improve upon our current approach. Early evidence suggests that body composition parameters repurposed from medical imaging data may improve upon height and weight as covariates of drug clearance and distribution. Clinical trials that can integrate human body phenotyping may help us identify new approaches to optimal dose selection of antimicrobials in patients with obesity.

The evolution of the neutrophil-lymphocyte ratio (NLR) and the platelet-lymphocyte ratio during polychemotherapy in head and neck cancers

The identification of prognostic and predictive biomarkers in oncological pathology is a desideratum of translational research in cancer. The neutrophil-lymphocyte ratio (NLR) and the platelet-lymphocyte ratio (PLR) were considered sug­ges­tive to characterize both cell-mediated immune sta­tus and inflammation in cancer, thus being potential bio­mar­kers. Due to the high rate of therapeutic failure even in the case of a treatment with curative potential, head and neck cancers are a priority in the research of po­ten­tial biomarkers that allow a stratification of risk groups in order to adapt the therapy. The aim of the study is the dynamic evaluation of NLR and nadir PLR and du­ring chemotherapy cycles for patients with multimodal, nonsurgically treated head and neck cancers. The mean NLR and PLR values vary during treatment, but the mean nadir value is not significantly different from the mean NLR and PLR values before the last cycle of chemotherapy. If there is solid evidence regarding the role of NLR nadir as a biomarker, the evaluation of NLR and PLR dynamics re­quires further research to confirm the possibility of being validated as a prognostic or predictive biomarker of re­sponse to chemotherapy and radiotherapy in head and neck squamous cell carcinoma.

Tests that now deserve to be more widely adopted in IBD clinical practice.

Inflammatory bowel diseases are chronic relapsing immune-mediated diseases of the intestinal tract with multifaceted manifestations and treatment related morbidity. Faecal and blood tests, radiological, endoscopic and histologic investigations are now widely used for managing both ulcerative colitis and Crohn’s disease. Over the years, a number of new investigations have been proposed but not widely adopted yet. Patients with Crohn’s disease may have multiple causes of diarrhoea, not always attributable to disease exacerbation, but sometimes linked to bile acid malabsorption; we have a reliable serum test, C4, that allows us to recognize and treat this cause of diarrhoea efficaciously and not empirically, but it is not available or used widely. There is genetic inter-individual variability in drug responses, in terms of both efficacy and toxicity, leading to high rates of therapeutic failure. Patients treated with thiopurine or, more rarely, 5-aminosalicylic acid may suffer from unpredictable and serious adverse events, some of these with pathogenesis related to genetic variants: myelosuppression, acute pancreatitis and nephrotoxicity. The identification of pre-treatment genetic tests can optimize therapeutic choice and avoid adverse events. With regard to biological drugs, patients can experience primary non-response or loss of response due to induction of immune responses to the drugs affecting drug efficacy and determining hypersensitivity reactions. We have specifically reviewed a number of investigations, whose use is currently limited, and highlighted four tests that deserve to be more widely incorporated in clinical practice as these could improve medical decision-making and patient outcomes.

Piperacillin-tazobactam should be preferred to third-generation cephalosporins to treat wild-type inducible AmpC-producing Enterobacterales in critically ill patients with hospital or ventilator-acquired pneumonia

PurposeTo compare the rate of therapeutic failure in critically ill patients treated by third-generation cephalosporins (3GCs) or piperacillin-tazobactam (PTZ) for wild-type AmpC-producing Enterobacterales pulmonary infections. MethodsOver a 4-year period, all adult patients treated for a wild-type AmpC-producing Enterobacterales pulmonary infection were retrospectively included. Two groups of patients were compared according to the definitive antibiotic therapy (3GCs or PTZ) considered after <48 h of empirical antibiotic therapy. The main outcome was the rate of therapeutic failure (impaired clinical response under treatment and/or a relapse of pulmonary infection). The secondary outcome was a secondary acquisition of 3GCs resistance. ResultsOver the study period, 244 patients were included; 56 (23%) experienced therapeutic failure. In the non-adjusted cohort, the rate of therapeutic failure and emergence of resistance were significantly higher in the 3GCs group (32 vs. 18%, p = .011 and 13 vs. 5%, p = .035, respectively). In the propensity score-matched population, the use of 3GCs was associated with higher rates of therapeutic failure (HR = 1.61 [1.27–2.07]). The secondary de-escalation to 3GCs after 48 h of PTZ as a first-line antibiotic therapy was not associated with increased rate of emergence of resistance. ConclusionOur study confirms that 3GCs should be avoided as first-line antibiotic therapy in wild-type AmpC-producing Enterobacterales pulmonary infections.

Predicting (side) effects for patients with inflammatory bowel disease: The promise of pharmacogenetics.

Inflammatory bowel disease (IBD) is a chronic and heterogeneous intestinal inflammatory disorder. The medical management of IBD aims for long-lasting disease remission to prevent complications and disease progression. Early introduction of immunosuppression forms the mainstay of medical IBD management. Large inter-individual variability in drug responses, in terms of both efficacy and toxicity, leads to high rates of therapeutic failure in the management of IBD. Better patient stratification is needed to maximize patient benefit and minimize the harm caused by adverse events. Pre-treatment pharmacogenetic testing has the potential to optimize drug selection and dose, and to minimize harm caused by adverse drug reactions. In addition, optimizing the use of cheap conventional drugs, and avoiding expensive ineffective drugs, will lead to a significant reduction in costs. Genetic variation in both TPMT and NUDT15, genes involved in thiopurine metabolism, is associated to an increased risk of thiopurine-induced myelosuppression. Moreover, specific HLA haplotypes confer risk to thiopurine-induced pancreatitis and to immunogenicity to tumor necrosis factor-antagonists, respectively. Falling costs and increased availability of genetic tests allow for the incorporation of pre-treatment genetic tests into clinical IBD management guidelines. In this paper, we review clinically useful pharmacogenetic associations for individualized treatment of patients with IBD and discuss the path from identification of a predictive pharmacogenetic marker to implementation into IBD clinical care.

Osteoarticular Implant Infections by Candida spp., experience at an elderly adults’ center

Background: Osteoarticular implant (OI) infections by Candida spp are a rare entity with high morbidity. The objective of this work is to describe the clinical and microbiological characteristics of OI Candida infections at an elderly adult center. Methods & Materials: We retrospectively studied patients with Candida spp isolation in osteoarticular surgical samples between January 2012 - September 2017. Only patients with the presence of compatible parameters of prosthetic infection were included: signs of inflammation, fistula, pain, functional impotence, elevation of sedimentation rate and C- reactive protein. We analyzed demographic, microbiological, therapeutic and evolutionary variables. Results: Five cases were identified, female, the median age 75 years (range 70-84). The indication of OI in 4 patients was osteoarthrosis (3 gonarthrosis and 1 coxarthrosis) and in 1 knee fracture. Comorbidities: arterial hypertension (n: 5), diabetes (n: 1). The 5 cases presented late chronic OI infection, with isolation of positive cocci and long term antibiotic treatment. An average of 3.6 surgical toilettes were performed, prior to the isolation of Candida spp. The most frequent manifestation of the fungal infection was pain (60%), dislocation (20%), fistula (20%). The isolated species were Candida albicans (2), Candida spp (2), Candida parapsilosis (1); three patients had simultaneous bacterial coinfection. In 3 patients, OI exchange was performed, retention of the OI in one and in another amputation. Treatment with echinocandins was started for 30 days in all cases. Four patients continued with prolonged oral treatment with fluconazole, 1 patient died of cause not related to the infectious event. Conclusion: In this study Candida infections in OI was observed in patients with a history of late chronic osteoarticular infection due to positive cocci, who received prolonged antimicrobial treatment and required multiple surgical interventions. Is important to consider that slime-producing germs such as Staphylococcus spp and Candida spp have a high rate of therapeutic failure, conditioning the quality of life of the elderly.

Association between augmented renal clearance, antibiotic exposure and clinical outcome in critically ill septic patients receiving high doses of β-lactams administered by continuous infusion: a prospective observational study

This study assessed whether augmented renal clearance (ARC) impacts negatively on antibiotic concentrations and clinical outcomes in patients treated by high-dose β-lactams administered continuously. Over a 9-month period, all critically ill patients without renal impairment treated by one of the monitored β-lactams for a documented infection were eligible. During the first 3 days of antibiotic therapy, every patient underwent 24-h CLCr measurements and therapeutic drug monitoring. The main outcome was the rate of β-lactam underdosing, defined as a free drug concentration <4 × MIC of the known pathogen. Secondary outcomes were rates of subexposure for β-lactams and therapeutic failure. The performance of CLCr in predicting underdosing was assessed by a ROC curve, and multivariable logistic regression was performed to determine risk factors for subexposure and therapeutic failure. A total of 79 patients were included and 235 samples were analysed. The rate of underdosing<4×MIC was 12%, with a significant association with CLCr (P < 0.0001). A threshold of CLCr ≥ 170 mL/min had a sensitivity and specificity of 0.93 (95% CI 0.77–0.99) and 0.65 (95% CI 0.58–0.71) for predicting β-lactam underdosing<4×MIC. Mean CLCr values ≥170 mL/min were significantly associated with subexposure<4xMIC [OR = 10.1 (2.4–41.6); P = 0.001]. Patients with subexposure<4×MIC presented higher rates of therapeutic failure [OR = 6.3 (1.2–33.2); P = 0.03]. Mean CLCr values ≥170 mL/min remain a risk factor for subexposure to β-lactams despite high doses of β-lactams administered continuously. β-Lactam subexposure was associated with higher rates of therapeutic failure in septic critically ill patients.

Memantine for the treatment of general neuropathic pain: a narrative review.

Neuropathic pain (NP) is difficult to treat and is associated with a decline in quality of life. NP aetiologies are numerous and a number of pathologies display neuropathic characteristics. Of the various N-methyl-d-aspartate antagonists that are alternatives to be recommended in first-line NP treatment, memantine has the safest side-effect profile and has long been approved in Alzheimer's disease. The review covers memantine studies in postherpetic neuralgia, diabetic pain, postoperative pain, complex regional pain syndrome, chronic phantom limb pain, opioid-refractory pain and fibromyalgia. Results were inconclusive because of studies with poor levels of evidence, paucity of trials and small samples. Two recent randomized trials, however, showed significant efficacy of memantine: one demonstrated prophylactic effects against postoperative neuralgia and pain-associated psychological impairment; in the other, memantine improved pain and cognition in fibromyalgia. Both studies found no side effects or adverse events. Given the high rate of therapeutic failure in chronic states, often because of adverse events, the excellent benefit/risk ratio of memantine in these pilot studies encourages further exploration of this drug in NP prevention and in fibromyalgia in larger-scale studies.

Clinical and Diagnostic Aspects of Brucellosis and Antimicrobial Susceptibility of Brucella Isolates in Hamedan, Iran.

Current drug regimens for brucellosis are associated with relatively high rates of therapeutic failure or relapse. Reduced antimicrobial susceptibility of Brucella spp. has been proposed recently as a potential cause of therapeutic failure. The aim of this study was to evaluate the antibiotic resistance pattern of Brucella melitensis clinical isolates by E-test method in Hamadan, west of Iran. In a 15-month period, all patients with suspected brucellosis were enrolled. Blood specimens were collected for diagnosis of brucellosis by BACTEC system and serological tests. Antimicrobial susceptibility of clinical isolates to 7 antibiotics was assessed by the E-test method. One hundred forty-nine patients with brucellosis were evaluated. 38.3% of cultures of clinical samples were positive for BACTEC system, of which 91.2% were associated with a positive serological test result. No significant associations were found between serology and the culture method. All Brucella isolates were susceptible to doxycycline, streptomycin, gentamicin, ciprofloxacin, and moxifloxacin. However, decreased sensitivity to rifampin and trimethoprim-sulfamethoxazole was found in 35.1% and 3.5% of isolates, respectively. Because of the high rates of intermediate sensitivity to rifampin among Brucella isolates, this drug should be prescribed with caution. We recommend restricting the use of rifampin for treatment of brucellosis except as an alternative drug for special situations.

Accessory Gene Regulator Polymorphism and Vancomycin Minimum Inhibitory Concentration in Methicillin-Resistant Staphylococcus aureus.

BackgroundMethicillin-resistant Staphylococcus aureus (MRSA) bacteremia with a vancomycin minimum inhibitory concentration (MIC) of 2 µg/mL presents a high rate of therapeutic failure in response to vancomycin. In addition, polymorphism in accessory gene regulator (agr) is associated with vancomycin therapeutic effects. The association between agr polymorphism and vancomycin MICs was investigated in MRSA isolates.MethodsAgr group-specific PCR was conducted on 118 MRSA bloodstream isolates. Vancomycin susceptibility tests were conducted, while E-test GRD (bioMérieux SA, France) was used to detect heterogeneous vancomycin-intermediate S. aureus (hVISA).ResultsOf the 118 MRSA isolates, 59 (50.0%), 43 (36.4%), and 10 (8.5%) isolates belonged to agr group I, II, and III, respectively. Six isolates could not be classified. Twenty-six, 73, and 19 isolates presented a vancomycin MIC of 2, 1, and 0.5 µg/mL, respectively. Nine (34.6%), 14 (53.8%), and 2 (7.7%) isolates with MICs of 2 µg/mL belonged to agr group I, II, and III, respectively. Thirty-seven (50.6%), 26 (35.6%), and 6 (8.2%) isolates with MICs of 1 µg/mL belonged to agr group I, II, and III, respectively. Thirteen (68.4%), 3 (15.8%), and 2 (10.5%) isolates with MICs of 0.5 µg/mL belonged to agr group I, II, and III, respectively. The agr group II presented more isolates with MIC of 2 µg/mL (32.6%) than the agr non-group II (16%). Four isolates tested positive for hVISA. Three of them belonged to agr group II.ConclusionsMRSA isolates with vancomycin MIC of 2 µg/mL were more common in agr group II than in agr non-group II.

Effect of initial empiric antibiotic therapy combined with control of the infection focus on the prognosis of patients with secondary peritonitis.

In patients with intra-abdominal infection, inappropriate initial empiric antibiotic therapy is associated with greater morbidity. We evaluated the impact of adequate empiric antibiotic treatment together with control of the infection focus on the morbidity and mortality rates of patients with secondary peritonitis. This was a prospective, observational study with the participation of 24 Spanish hospitals and 362 patients with secondary peritonitis (262 community-acquired, 100 post-operative). Therapeutic failure (infectious complications or death) was classified into four categories according to whether empiric antibiotic treatment was appropriate and the infection focus was controlled. The rates of therapeutic failure, re-operation, and mortality were 48%, 13%, and 8%, respectively. Empiric antibiotic treatment was inappropriate in 39% of cases, which was associated with a higher rate of surgical site infection (53% vs. 40%; p=0.031) and death (12% vs. 5%; p=0.021) than was observed in patients receiving appropriate initial empiric therapy. Eight percent of patients in whom control of the infection focus was not obtained suffered from more infectious complications (76% vs. 52%; p=0.01) and surgical site infections (69% vs. 44%; p=0.01); and in this group, both therapeutic failure and mortality rates were similar, independent of whether the empiric antibiotic therapy was appropriate. Inappropriate initial empiric antibiotic therapy was associated with higher rates of therapeutic failure, surgical site infection, re-operation, and death. Classification of therapeutic failure into four categories according to the appropriateness of empiric antibiotic therapy and the success of infection control provided excellent discrimination of morbidity and death.

Vancomycin revisited - 60 years later.

Vancomycin is one of the older antibiotics that has been now in clinical use close to 60 years. Earlier on, vancomycin was associated with many side effects including vestibular and renal, most likely due to impurities contained in early vancomycin lots. Over the years, the impurities have been removed and the compound has now far less vestibular adverse effects, but still possesses renal toxicity if administered at higher doses rendering trough serum levels of >15 mcg/mL or if administered for prolonged periods of time. Vancomycin is effective against most Gram-positive cocci and bacilli with the exception of rare organisms as well as enterococci that became vancomycin resistant, mostly Enterococcus faecium. The major use of vancomycin today is for infections caused by methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant Staphylococcus epidermidis (MRSE) and amoxicillin-resistant enterococci. In its oral form, vancomycin is used to treat diarrhea caused by Clsotridium difficile. With S. aureus, there are only a handful of vancomycin-resistant strains. Nevertheless, a “vancomycin creep” that is slow upward trending of vancomycin MIC from <1 mcg/mL to higher values has been noted in several parts of the world, but not globally, and strains that have MIC’s of 1.5–2 mcg/mL are associated with high therapeutic failure rates. This phenomenon has also been recently recognized in methicillin-susceptible S. aureus (MSSA). While vancomycin is relatively a safe agent adverse events include the “red man” syndrome, allergic reactions, and various bone marrow effects as well as nephrotoxicity. Vancomycin has been a very important tool in our therapeutic armamentarium that remained effective for many years, it is likely remain effective as long as resistance to vancomycin remains controlled.

Assessing micafungin/triazole combinations for the treatment of invasive scedosporiosis due to Scedosporium apiospermum and Scedosporium boydii.

Scedosporium infections are associated with high therapeutic failure rates. Combination therapy may be an alternative approach to improve outcome. The in vitro and in vivo efficacy of micafungin plus posaconazole or plus voriconazole was investigated herein. Scedosporium boydii (n = 17) and Scedosporium apiospermum (n = 26) were tested using the chequerboard method according to CLSI M38-A2 guidelines and the fractional inhibitory concentration index (FICI) was evaluated. In vivo outcome of micafungin plus posaconazole or micafungin plus voriconazole against two isolates of each of the mentioned species was evaluated in a well-established, immunocompromised, haematogenous murine model of systemic scedosporiosis. Survival and tissue burden in kidneys and brain were investigated. The FICI category of 'no interaction' was most frequent, while 'synergism' or 'antagonism' was rarely observed. FICI failed to predict the in vivo outcome of both combinatorial treatment strategies. In vivo outcome was strain-dependent rather than species-dependent, even though effects on fungal tissue burden were more pronounced for S. boydii. Both combinations improved survival significantly when compared with untreated controls and micafungin monotherapy. Voriconazole and posaconazole did not differ in their efficacy and micafungin failed to be effective. Combinations were by trend better than voriconazole and posaconazole as single therapy, but statistically significant differences were lacking. No benefit of the azole/echinocandin combination was found when compared with voriconazole and posaconazole monotherapies. FICI failed to predict the outcome of in vivo drug combinations in the murine study.

Multidrug-resistant bacterial infections after liver transplantation: An ever-growing challenge

Bacterial infections are a leading cause of morbidity and mortality among solid organ transplant recipients. Over the last two decades, various multidrug-resistant (MDR) pathogens have emerged as relevant causes of infection in this population. Although this fact reflects the spread of MDR pathogens in health care facilities worldwide, several factors relating to the care of transplant donor candidates and recipients render these patients particularly prone to the acquisition of MDR bacteria and increase the likelihood of MDR infectious outbreaks in transplant units. The awareness of this high vulnerability of transplant recipients to infection leads to the more frequent use of broad-spectrum empiric antibiotic therapy, which further contributes to the selection of drug resistance. This vicious cycle is difficult to avoid and leads to a scenario of increased complexity and narrowed therapeutic options. Infection by MDR pathogens is more frequently associated with a failure to start appropriate empiric antimicrobial therapy. The lack of appropriate treatment may contribute to the high mortality occurring in transplant recipients with MDR infections. Furthermore, high therapeutic failure rates have been observed in patients infected with extensively-resistant pathogens, such as carbapenem-resistant Enterobacteriaceae, for which optimal treatment remains undefined. In such a context, the careful implementation of preventive strategies is of utmost importance to minimize the negative impact that MDR infections may have on the outcome of liver transplant recipients. This article reviews the current literature regarding the incidence and outcome of MDR infections in liver transplant recipients, and summarizes current preventive and therapeutic recommendations.

Multidrug-resistant endemic clonal strain of Candida auris in India

Candida auris is a recently described rare agent of fungemia. It is notable for its antifungal resistance. A total of 15 C. auris isolates, originating from seven cases of fungemia, three cases of diabetic gangrenous foot, and one case of bronchopneumonia from a tertiary care hospital in south India, were investigated. All of the 15 isolates were identified by sequencing and 14 of these along with 12 C. auris isolates previously reported from two hospitals in Delhi, north India, two each from Japan and Korea were genotyped by amplified fragment length polymorphism (AFLP). In vitro antifungal susceptibility testing (AFST) was done by the Clinical and Laboratory Standards Institute (CLSI) broth microdilution method. Candida auris isolates were misidentified as Candida haemulonii by VITEK. All were resistant to fluconazole [geometric mean minimum inhibitory concentration (MIC) 64 μg/ml] and 11 isolates were resistant to voriconazole (MIC ≥1 μg/ml). Forty-seven percent of the C. auris isolates were resistant to flucytosine (MIC ≥64 μg/ml) and 40% had high MIC (≥1 μg/ml) of caspofungin. Breakthrough fungemia developed in 28.6% of patients and therapeutic failure in 4 (66.7%) patients. Interestingly, the 26 Indian C. auris isolates from north and south India were clonal and phenotypically and genotypically distinct from Korean and Japanese isolates. The present study demonstrates that C. auris is a potential emerging pathogen that can cause a wide spectrum of human mycotic infections. The prevalence of a C. auris endemic clonal strain resistant to azoles and other antifungals in Indian hospitals with high rates of therapeutic failure in cases of fungemia is worrisome.