Comparison of ß-1-3-D-Glucan and Candida Mannan Biomarker Assays with Serological Tests for the Diagnosis of Candidemia.

Invasive candidiasis, including bloodstream infection (candidemia), encompasses the most severe forms of Candida infection. Several species-specific and non-specific serological assays are commercially available to aid in diagnosis. This study compared the performance of five such biomarker assays. Serum samples from 14 patients with proven or probable invasive candidiasis, and from 10 control patients, were included in the analysis. A total of 50 serum samples were tested using C. albicans germ tube antibody (CAGTA) assay (Vircell), C. albicans IgM, C. albicans IgG and Candida mannan assays (Dynamiker Biotechnology). Among these samples, the ß-1-3-D-glucan (BDG) assay (Fungitell), a laboratory standard for the diagnosis of invasive candidiasis, was positive in 20 (40%), intermediate in five (10%) and negative in 25 (50%). In cases of proven or probable candidemia, the sensitivity and specificity of the BDG assay was 86% and 80%, respectively; the Candida mannan assay, 14% and 86%; the CAGTA test, 57% and 60%; the C. albicans IgM assay, 71% and 60%; and C. albicans IgG assay 29% and 90%. In 4/8 (50%) cases with multiple serum samples, C. albicans IgM was positive sooner than BDG. Thus, when used as a rule-out test for invasive candidiasis, our data suggest that the C. albicans IgM assay may assist antifungal stewardship (over serum BDG).

A qualitative interview study applying the COM-B model to explore how hospital-based trainers implement antimicrobial stewardship education and training in UK hospital-based care.

BACKGROUND: Antimicrobial resistance (AMR) is a major global health threat caused by the inappropriate use of antimicrobials in healthcare and other settings. Antimicrobial stewardship (AMS) is a broad multi-component health services intervention that promotes and monitors the judicious use of antimicrobials to preserve their future effectiveness. A main component of AMS is education and training (E&T). However, there are often discrepancies in how such interventions are implemented and delivered in hospital-based care. The aim of this study was to explore the factors influencing the implementation of AMS E&T in UK hospitals. METHODS: Semi-structured interviews were carried out with AMS E&T trainers in UK hospitals. The interview schedule was developed using the Capability, Opportunity, Motivation = Behaviour (COM-B) model. Participants were identified via professional networks and social media. Interviews were analysed using inductive thematic analysis, followed by deductive analysis using the COM-B model as a framework. RESULTS: A total of 34 participants (26 antimicrobial pharmacists, 3 nurses, 1 advanced clinical practitioner, 2 infectious disease consultants, 1 microbiologist and 1 clinical scientist). responsible for designing, implementing and evaluating AMS E&T in UK hospitals (five from Northern Ireland, four from Wales, two from Scotland and 23 from England) took part in virtual interviews. Key themes were: (1) The organisational context, including system-level barriers to AMS included competing organisational targets (Reflective motivation and physical opportunity) and the impact of the COVID-19 pandemic on activity (Physical opportunity); (2) Healthcare professionals' roles and the wider multi-disciplinary team, such that AMS roles were defined and addressed poorly in E&T (Social opportunity); and (3) The individual perception of the need for AMS E&T in hospital-based care, manifest in a perceived lack of conviction of the wider threat of AMR and the resulting need for AMS E&T (Reflective motivation). CONCLUSION: This study has identified factors influencing implementation of AMS E&T in UK hospitals and further identified where implemented, AMS E&T did not address real-world challenges. Current AMS E&T needs to be optimised to elicit practice change, with recommendations including training and engaging the wider work-force and drawing upon theoretically-informed intervention development frameworks to inform AMS E&T to better target AMS behaviour change.

Absence of Azole Antifungal Resistance in Aspergillus fumigatus Isolated from Root Vegetables Harvested from UK Arable and Horticultural Soils.

The emergence of azole-resistant Aspergillus fumigatus (ARAf) complicates the treatment of aspergillosis and can nearly double the mortality from invasive aspergillosis (IA). ARAf has been isolated from many different environmental sites and indoor environments and thus presents a significant risk for susceptible patients. Local surveillance of environmental ARAf can guide antifungal prescribing and improve patient outcomes. In this study, seventy-four soils samples collected from the surface of a variety of root vegetables from farm shops and private gardens covering a wide geographical area of the UK, were cultured to assess the presence of A. fumigatus, and the prevalence and nature of any resistance mechanisms. A high-throughput in-house antifungal susceptibility screening method was developed and validated using the EUCAST MIC reference method, E.DEF 9.3.1. A total of 146 isolates were recovered and analysed. Even though the study premise was that soil-covered root vegetables and other fresh produce could represent a conduit for ARAf exposure in vulnerable patients, no ARAf were found in the soil samples despite 55% of samples harbouring A. fumigatus. The sample type and screening method used could be suitable for more extensive monitoring of the soil to detect trends in the prevalence of ARAf.

Positive Aspergillus PCR as a marker of azole resistance or sub-therapeutic antifungal therapy in patients with chronic pulmonary aspergillosis.

BACKGROUND: Chronic pulmonary aspergillosis (CPA) is a progressive respiratory disease, caused most commonly by A fumigatus, with significant morbidity and mortality. Azole resistance in A fumigatus is a growing concern worldwide, with resistance to itraconazole reported in up to 50% of patients. AIM: The aim of this study was to determine whether a positive Aspergillus PCR (polymerase chain reaction) is a marker of resistance in CPA patients on azole therapy. METHODS: Patients were selected via a consecutive database search for the first 50 CPA patients with a positive Aspergillus PCR from January to September 2016. Data were collected regarding concurrent and subsequent culture results, current therapy and serum antifungal levels. PCR-positive patients not on therapy were included as the control group. RESULTS: Twenty-three patients were on therapy (15 itraconazole, 4 voriconazole and 4 posaconazole). Cycle threshold (Ct) values ranged from 20.8 to 37.9; no significant difference was found between each treatment and the control group (P = .47). In treated patients, concurrent azole-resistant A fumigatus was found in 75% of A fumigatus-positive cultures (6/8). All of the resistant isolates in the itraconazole group showed therapy resistance. Twenty per cent of all itraconazole levels were sub-therapeutic. No significant difference was found in serum itraconazole levels for patients on itraconazole with a positive PCR versus negative PCR (P = .44). CONCLUSION: Positive sputum, Aspergillus-specific PCR can be associated with azole resistance in CPA patients on therapy.

A Multispecies Cluster of GES-5 Carbapenemase-Producing Enterobacterales Linked by a Geographically Disseminated Plasmid.

BACKGROUND: Early and accurate treatment of infections due to carbapenem-resistant organisms is facilitated by rapid diagnostics, but rare resistance mechanisms can compromise detection. One year after a Guiana Extended-Spectrum (GES)-5 carbapenemase-positive Klebsiella oxytoca infection was identified by whole-genome sequencing (WGS; later found to be part of a cluster of 3 cases), a cluster of 11 patients with GES-5-positive K. oxytoca was identified over 18 weeks in the same hospital. METHODS: Bacteria were identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry, antimicrobial susceptibility testing followed European Committee on Antimicrobial Susceptibility Testing guidelines. Ertapenem-resistant isolates were referred to Public Health England for characterization using polymerase chain reaction (PCR) detection of GES, pulsed-field gel electrophoresis (PFGE), and WGS for the second cluster. RESULTS: The identification of the first GES-5 K. oxytoca isolate was delayed, being identified by WGS. Implementation of a GES-gene PCR informed the occurrence of the second cluster in real time. In contrast to PFGE, WGS phylogenetic analysis refuted an epidemiological link between the 2 clusters; it also suggested a cascade of patient-to-patient transmission in the later cluster. A novel GES-5-encoding plasmid was present in K. oxytoca, Escherichia coli, and Enterobacter cloacae isolates from unlinked patients within the same hospital group and in human and wastewater isolates from 3 hospitals elsewhere in the United Kingdom. CONCLUSIONS: Genomic sequencing revolutionized the epidemiological understanding of the clusters; it also underlined the risk of covert plasmid propagation in healthcare settings and revealed the national distribution of the resistance-encoding plasmid. Sequencing results also informed and led to the ongoing use of enhanced diagnostic tests for detecting carbapenemases locally and nationally.

Invasive fungal infections in the immunocompromised host: Mechanistic insights in an era of changing immunotherapeutics.

The use of cytotoxic chemotherapy in the treatment of malignant and inflammatory disorders is beset by considerable adverse effects related to nonspecific cytotoxicity. Accordingly, a mechanistic approach to therapeutics has evolved in recent times with small molecular inhibitors of intracellular signaling pathways involved in disease pathogenesis being developed for clinical use, some with unparalleled efficacy and tolerability. Nevertheless, there are emerging concerns regarding an association with certain small molecular inhibitors and opportunistic infections, including invasive fungal diseases. This is perhaps unsurprising, given that the molecular targets of such agents play fundamental and multifaceted roles in orchestrating innate and adaptive immune responses. Nevertheless, some small molecular inhibitors appear to possess intrinsic antifungal activity and may therefore represent novel therapeutic options in future. This is particularly important given that antifungal resistance is a significant, emerging concern. This paper is a comprehensive review of the state-of-the-art in the molecular immunology to fungal pathogens as applied to existing and emerging small molecular inhibitors.

Evaluating training for a simulated team in complex whole procedure simulations in the endovascular suite.

INTRODUCTION: Simulators supporting the development of technical skills for complex procedures are gaining prominence. Safe performance of complex procedures requires effective team interactions. Our research group creates 'whole' procedure simulations to produce the psychological fidelity of clinical settings. Recruitment of real interventional team (IT) members has proved challenging. Actors as a simulated team are expensive. We hypothesised that medical students and trainees in a vascular unit could authentically portray members of the endovascular suite for carotid stenting. METHODS: This paper describes the evaluation of a training programme for a simulated IT. Participants rated the extent to which programmes objectives were met and realism of simulations. Researchers' field notes provided insight into strengths and weaknesses of the programme. RESULTS: Seven members from the vascular unit undertook training. Learning objectives were largely met. Nineteen simulations with 13 interventionalists were performed. Realism levels were at least moderate. Simulated IT members reported increased understanding of teamwork and roles in the endovascular suite. DISCUSSION: A simulated IT proved feasible. Authentic psychological fidelity complemented the physical fidelity of the simulated suite. Although there were areas for development in training, this approach might contribute considerably to interventionalist training and increase knowledge and skills of vascular trainees and medical students.