Modern Solutions for Ancient Pathogens: Direct Pathogen Sequencing for Diagnosis of Lepromatous Leprosy and Cerebral Coenurosis.

Microbes unculturable in vitro remain diagnostically challenging, dependent historically on clinical findings, histology, or targeted molecular detection. We applied whole-genome sequencing directly from tissue to diagnose infections with mycobacteria (leprosy) and parasites (coenurosis). Direct pathogen DNA sequencing provides flexible solutions to diagnosis of difficult pathogens in diverse contexts.

Molecular epidemiology and antimicrobial resistance phenotype of paediatric bloodstream infections caused by Gram-negative bacteria.

Background: Gram-negative organisms are common causes of bloodstream infection (BSI) during the neonatal period and early childhood. Whilst several large studies have characterised these isolates in adults, equivalent data (particularly incorporating whole genome sequencing) is lacking in the paediatric population. Methods: We perform an epidemiological and sequencing based analysis of Gram-negative bloodstream infections (327 isolates (296 successfully sequenced) from 287 patients) in children <18 years old between 2008 and 2018 in Oxfordshire, UK. Results: Here we show that the burden of infection lies predominantly in neonates and that most infections are caused by Escherichia coli, Klebsiella spp. and Enterobacter hormaechei. There is no evidence in our setting that the proportion of antimicrobial resistant isolates is increasing in the paediatric population although we identify some evidence of sub-breakpoint increases in gentamicin resistance. The population structure of E. coli BSI isolates in neonates and children mirrors that in adults with a predominance of STs 131/95/73/69 and the same proportions of O-antigen serotypes. In most cases in our setting there is no evidence of transmission/point-source acquisition and we demonstrate the utility of whole genome sequencing to refute a previously suspected outbreak. Conclusions: Our findings support continued use of current empirical treatment guidelines and suggest that O-antigen targeted vaccines may have a role in reducing the incidence of neonatal sepsis.

Genomic surveillance of Escherichia coli and Klebsiella spp. in hospital sink drains and patients.

Escherichia coli and Klebsiella spp. are important human pathogens that cause a wide spectrum of clinical disease. In healthcare settings, sinks and other wastewater sites have been shown to be reservoirs of antimicrobial-resistant E. coli and Klebsiella spp., particularly in the context of outbreaks of resistant strains amongst patients. Without focusing exclusively on resistance markers or a clinical outbreak, we demonstrate that many hospital sink drains are abundantly and persistently colonized with diverse populations of E. coli, Klebsiella pneumoniae and Klebsiella oxytoca, including both antimicrobial-resistant and susceptible strains. Using whole-genome sequencing of 439 isolates, we show that environmental bacterial populations are largely structured by ward and sink, with only a handful of lineages, such as E. coli ST635, being widely distributed, suggesting different prevailing ecologies, which may vary as a result of different inputs and selection pressures. Whole-genome sequencing of 46 contemporaneous patient isolates identified one (2 %; 95 % CI 0.05-11 %) E. coli urine infection-associated isolate with high similarity to a prior sink isolate, suggesting that sinks may contribute to up to 10 % of infections caused by these organisms in patients on the ward over the same timeframe. Using metagenomics from 20 sink-timepoints, we show that sinks also harbour many clinically relevant antimicrobial resistance genes including blaCTX-M, blaSHV and mcr, and may act as niches for the exchange and amplification of these genes. Our study reinforces the potential role of sinks in contributing to Enterobacterales infection and antimicrobial resistance in hospital patients, something that could be amenable to intervention. This article contains data hosted by Microreact.

Scope, quality, and inclusivity of clinical guidelines produced early in the covid-19 pandemic: rapid review.

OBJECTIVE: To appraise the availability, quality, and inclusivity of clinical guidelines produced in the early stage of the coronavirus disease 2019 (covid-19) pandemic. DESIGN: Rapid review. DATA SOURCES: Ovid Medline, Ovid Embase, Ovid Global Health, Scopus, Web of Science Core Collection, and WHO Global Index Medicus, searched from inception to 14 Mar 2020. Search strategies applied the CADTH database guidelines search filter, with no limits applied to search results. Further studies were identified through searches of grey literature using the ISARIC network. INCLUSION CRITERIA: Clinical guidelines for the management of covid-19, Middle East respiratory syndrome (MERS), and severe acute respiratory syndrome (SARS) produced by international and national scientific organisations and government and non-governmental organisations relating to global health were included, with no exclusions for language. Regional/hospital guidelines were excluded. Only the earliest version of any guideline was included. QUALITY ASSESSMENT: Quality was assessed using the Appraisal of Guidelines for Research and Evaluation (AGREE) II tool. The quality and contents of early covid-19 guidelines were also compared with recent clinical guidelines for MERS and SARS. RESULTS: 2836 studies were identified, of which 2794 were excluded after screening. Forty two guidelines were considered eligible for inclusion, with 18 being specific to covid-19. Overall, the clinical guidelines lacked detail and covered a narrow range of topics. Recommendations varied in relation to, for example, the use of antiviral drugs. The overall quality was poor, particularly in the domains of stakeholder involvement, applicability, and editorial independence. Links between evidence and recommendations were limited. Minimal provision was made for vulnerable groups such as pregnant women, children, and older people. CONCLUSIONS: Guidelines available early in the covid-19 pandemic had methodological weaknesses and neglected vulnerable groups such as older people. A framework for development of clinical guidelines during public health emergencies is needed to ensure rigorous methods and the inclusion of vulnerable populations. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020167361.

Academic medicine: the continuing challenges.

BACKGROUND: Numbers of academic medicine trainees have been declining internationally. Many countries have taken differing approaches to improving recruitment, with some having established pathways. In the UK, the academic foundation programme (AFP) is one such pathway aimed towards those interested in an academic medical career. Variation exists amongst universities with respect to application and success rates. As a group of AFP doctors, we aimed to explore these issues. Numbers of academic medicine trainees have been declining internationally METHODS: We created and implemented a 1-day national course, comprising lectures and small group workshops, geared towards informing applicants about the AFP. It was evaluated via pre- and post-course questionnaires using a Likert scale, ranging from 1 to 5. We created and implemented a 1-day national course, comprising lectures and small group workshops, geared towards informing applicants about the AFP RESULTS: A total of 150 attendees were present from 16 different medical schools; 95% (143/150) of the attendees filled in both questionnaires. Attendees appeared unaware of the stages involved in the application process and felt underprepared. Following the course, learners reported median scores (with interquartile limits) that demonstrated increased overall knowledge, from 2 (1) to 4 (1) (p < 0.01), and increased preparedness, from 2 (1) to 3 (1) (p < 0.01). DISCUSSION: Our findings indicate that recruitment remains challenging, even in countries with established pathways. In the UK, the awareness of these pathways appears to be poor and courses such as ours may remedy that. Further exploration into the most effective methods to increase recruitment is necessary. The effect of institutional disparities in research culture and impact on application success needs investigation. Perhaps medical schools should introduce students to the prospect of academic careers earlier in training. Globally, efforts still need to be concentrated largely towards establishing integrated pathways.

A systematic review of clinical guidelines on the management of acute, community-acquired CNS infections.

BACKGROUND: The epidemiology of CNS infections in Europe is dynamic, requiring that clinicians have access to up-to-date clinical management guidelines (CMGs) to aid identification of emerging infections and for improving quality and a degree of standardisation in diagnostic and clinical management practices. This paper presents a systematic review of CMGs for community-acquired CNS infections in Europe. METHODS: A systematic review. Databases were searched from October 2004 to January 2019, supplemented by an electronic survey distributed to 115 clinicians in 33 European countries through the CLIN-Net clinical network of the COMBACTE-Net Innovative Medicines Initiative. Two reviewers screened records for inclusion, extracted data and assessed the quality using the AGREE II tool. RESULTS: Twenty-six CMGs were identified, 14 addressing bacterial, ten viral and two both bacterial and viral CNS infections. Ten CMGs were rated high quality, 12 medium and four low. Variations were identified in the definition of clinical case definitions, risk groups, recommendations for differential diagnostics and antimicrobial therapy, particularly for paediatric and elderly populations. CONCLUSION: We identified variations in the quality and recommendations of CMGs for community-acquired CNS infections in use across Europe. A harmonised European "framework-CMG" with adaptation to local epidemiology and risks may improve access to up-to-date CMGs and the early identification and management of (re-)emerging CNS infections with epidemic potential.

Prediction of Susceptibility to First-Line Tuberculosis Drugs by DNA Sequencing.

BACKGROUND: The World Health Organization recommends drug-susceptibility testing of Mycobacterium tuberculosis complex for all patients with tuberculosis to guide treatment decisions and improve outcomes. Whether DNA sequencing can be used to accurately predict profiles of susceptibility to first-line antituberculosis drugs has not been clear. METHODS: We obtained whole-genome sequences and associated phenotypes of resistance or susceptibility to the first-line antituberculosis drugs isoniazid, rifampin, ethambutol, and pyrazinamide for isolates from 16 countries across six continents. For each isolate, mutations associated with drug resistance and drug susceptibility were identified across nine genes, and individual phenotypes were predicted unless mutations of unknown association were also present. To identify how whole-genome sequencing might direct first-line drug therapy, complete susceptibility profiles were predicted. These profiles were predicted to be susceptible to all four drugs (i.e., pansusceptible) if they were predicted to be susceptible to isoniazid and to the other drugs or if they contained mutations of unknown association in genes that affect susceptibility to the other drugs. We simulated the way in which the negative predictive value changed with the prevalence of drug resistance. RESULTS: A total of 10,209 isolates were analyzed. The largest proportion of phenotypes was predicted for rifampin (9660 [95.4%] of 10,130) and the smallest was predicted for ethambutol (8794 [89.8%] of 9794). Resistance to isoniazid, rifampin, ethambutol, and pyrazinamide was correctly predicted with 97.1%, 97.5%, 94.6%, and 91.3% sensitivity, respectively, and susceptibility to these drugs was correctly predicted with 99.0%, 98.8%, 93.6%, and 96.8% specificity. Of the 7516 isolates with complete phenotypic drug-susceptibility profiles, 5865 (78.0%) had complete genotypic predictions, among which 5250 profiles (89.5%) were correctly predicted. Among the 4037 phenotypic profiles that were predicted to be pansusceptible, 3952 (97.9%) were correctly predicted. CONCLUSIONS: Genotypic predictions of the susceptibility of M. tuberculosis to first-line drugs were found to be correlated with phenotypic susceptibility to these drugs. (Funded by the Bill and Melinda Gates Foundation and others.).

Enhanced Methodologies for Detecting Phenotypic Resistance in Mycobacteria.

Lipid droplets found in algae and other microscopic organisms have become of interest to many researchers partially because they carry the capacity to produce bio-oil for the mass market. They are of importance in biology and clinical practice because their presence can be a phenotypic marker of an altered metabolism, including reversible resistance to antibiotics, prompting intense research.A useful stain for detecting lipid bodies in the lab is Nile red. It is a dye that exhibits solvatochromism; its absorption band varies in spectral position, shape and intensity with the nature of its solvent environment, it will fluoresce intensely red in polar environment and blue shift with the changing polarity of its solvent. This makes it ideal for the detection of lipid bodies within Mycobacterium spp. This is because mycobacterial lipid bodies' primary constituents are nonpolar lipids such as triacylglycerols but bacterial cell membranes are primarily polar lipid species. In this chapter we describe an optimal method for using Nile red to distinguish lipid containing (Lipid rich or LR cells) from those without lipid bodies (Lipid Poor or LP). As part of the process we have optimized a method for separating LP and LR cells that does not require the use of an ultracentrifuge or complex separation media. We believe that these methods will facilitate further research in these enigmatic, transient and important cell states.

Phenotypic resistance in mycobacteria: is it because I am old or fat that I resist you?

OBJECTIVES: We aimed to explore the phenomenon of phenotypic resistance to antimycobacterial antibiotics and to determine whether this was associated with cell age or the presence of lipid bodies. METHODS: The accumulation of lipid-body-positive [lipid-rich (LR)] cells was followed using cell staining and flow cytometry. LR cells of Mycobacterium smegmatis, Mycobacterium marinum, Mycobacterium fortuitum and Mycobacterium bovis (BCG) were separated from non-lipid-body-containing [lipid-poor (LP)] cells and their MBCs determined. We also compared the MBCs for LR and LP cells from 'old' and 'young' cultures. RESULTS: The LR cells of all species were more resistant to antibiotics than LP cells. For BCG, the susceptibility ratios were as follows: rifampicin, 5×; isoniazid, 16.7×; ethambutol, 5×; and ciprofloxacin, 5×. Phenotypic resistance was found in LR cells irrespective of cell age. CONCLUSIONS: We have shown that phenotypic antibiotic resistance is associated with the presence of lipid bodies irrespective of cell age. These data have important implications for our understanding of relapse in mycobacterial infections.