Ultrasensitive Amplification Refractory Mutation System Real-Time PCR (ARMS RT-PCR) Assay for Detection of Minority Hepatitis B Virus-Resistant Strains in the Era of Personalized Medicine

Resistance to antiviral treatment for chronic hepatitis B virus (HBV) has been associated with mutations in the HBV polymerase region. This study aimed at developing an ultrasensitive method for quantifying viral populations with all major HBV resistance-associated mutations, combining the amplification refractory mutation system real-time PCR (ARMS RT-PCR) with a molecular beacon using a LightCycler. The discriminatory ability of this method, the ARMS RT-PCR with molecular beacon assay, was 0.01 to 0.25% for the different HBV resistance-associated mutations, as determined by laboratory-synthesized wild-type (WT) and mutant (Mut) target sequences. The assay showed 100% sensitivity for the detection of mutant variants A181V, T184A, and N236T in samples from 41 chronically HBV-infected patients under antiviral therapy who had developed resistance-associated mutations detected by direct PCR Sanger sequencing. The ratio of mutant to wild-type viral populations (the Mut/WT ratio) was >1% in 38 (63.3%) of 60 samples from chronically HBV-infected nucleos(t)ide analogue-naive patients; combinations of mutations were also detected in half of these samples. The ARMS RT-PCR with molecular beacon assay achieved high sensitivity and discriminatory ability compared to the gold standard of direct PCR Sanger sequencing in identifying resistant viral populations in chronically HBV-infected patients receiving antiviral therapy. Apart from the dominant clones, other quasispecies were also quantified. In samples from chronically HBV-infected nucleos(t)ide analogue-naive patients, the assay proved to be a useful tool in detecting minor variant populations before the initiation of the treatment. These observations need further evaluation with prospective studies before they can be implemented in daily practice.     

Developing a risk prediction model for 30-day unplanned hospitalization in patients receiving outpatient parenteral antimicrobial therapy

ObjectivesOutpatient parenteral antimicrobial therapy (OPAT) is increasingly used to treat a wide range of infections. However, there is risk of hospital readmissions. The study aim was to develop a prediction model for the risk of 30-day unplanned hospitalization in patients receiving OPAT.MethodsUsing a retrospective cohort design, we retrieved data on 1073 patients who received OPAT over 2 years (January 2015 to January 2017) at a large teaching hospital in Sheffield, UK. We developed a multivariable logistic regression model for 30-day unplanned hospitalization, assessed its discrimination and calibration abilities, and internally them validated using bootstrap resampling.ResultsThe 30-day unplanned hospitalization rate was 11% (123/1073). The main indication for hospitalization was worsening or nonresponse of infection (52/123, 42%). The final regression model consisted of age (adjusted odds ratio (aOR), 1.18 per decade; 95% confidence interval (CI), 1.04–1.34), Charlson comorbidity score (aOR, 1.11 per unit increase; 95% CI, 1.00–1.23), prior hospitalizations in past 12 months (aOR, 1.30 per admission; 95% CI, 1.17–1.45), concurrent intravenous antimicrobial therapy (aOR, 1.89; 95% CI, 1.03–3.47) and endovascular infection (aOR, 3.51; 95% CI, 1.49–8.28). Mode of OPAT treatment was retained in the model as a confounder. The model had adequate concordance (c-statistic 0.72; 95% CI 0.67–0.77) and calibration (Hosmer-Lemeshow p 0.546; calibration slope 0.99; 95% CI 0.78–1.21), and low degree of optimism (bootstrap optimism corrected c-statistic, 0.70).ConclusionsWe identified a set of six important predictors of unplanned hospitalization based on readily available data. The prediction model may help improve OPAT outcomes through better identification of high-risk patients and provision of tailored care.     

Linezolid: effectiveness and safety for approved and off-label indications

Multi-drug resistant Gram-positive cocci have emerged as significant pathogens of community- and hospital-acquired infections. Several antimicrobial agents that can be used for the treatment of these infections are presently available. However, the most appropriate treatment for each infection has not been established. Linezolid seems to be a promising choice. Linezolid is bactericidal against Streptococci and bacteriostatic against Enterococci and Staphylococci. It has excellent pharmacokinetic and pharmacodynamic profiles, which allow early change from intravenous to oral administration. In addition, its effectiveness for the treatment of Gram-positive infections in immunocompetent and immunodeficient patients have been studied in several randomized controlled trials. In this review, the authors summarize all the available evidence regarding the effectiveness and safety of linezolid compared with other antimicrobial agents for its approved and off-label indications.     

Complications in pregnancy after bariatric surgery

Introduction

The application of bariatric surgery has recently spread among obese women including women of reproductive age.

Materials and methods

We sought to present three cases of obese women undergoing bariatric surgery, their monitoring and complications during pregnancy.

Conclusion

We suggest that conception should be postponed for at least 18 months after bariatric operation to avoid complications concerning both mother and fetus mainly associated with nutritional deficiencies due to the anatomical and physiological changes of such operations.     

Do PubMed and Google searches help medical students and young doctors reach the correct diagnosis? A pilot study

BackgroundIn the era of the World Wide Web we sought to examine whether the use of PubMed and Google can help physicians to improve their diagnostic skills.MethodsTwenty-six diagnostic cases presented in the case records of the New England Journal of Medicine during 2005 were used for our analysis. Three investigators (one trainee doctor and two final year medical students), tried determining the diagnosis, initially without and afterwards with the use of PubMed and Google.ResultsA slight increase in the proportion of correct diagnoses obtained was seen following the employment of the formerly mentioned Internet resources, specifically 15.4%, 2.9%, and 11.5% increase for the 3 investigators respectively (from 17 correct diagnoses out of the 26 cases to 21 correct diagnoses out of 26 for investigator A, from 11/26 to 12/26 for investigator B, and from 11/26 to 13/26 for investigator C). This increase was not statistically significant. One investigator was helped more by Google, one by PubMed, and one was equally assisted by the two resources.ConclusionsWe believe that these preliminary findings justify the induction of further studies in order to clarify whether resources such as PubMed and Google may substantially aid physicians and medical students in the differential diagnosis process.     

Daptomycin for endocarditis and/or bacteraemia: a systematic review of the experimental and clinical evidence

BACKGROUND: Endocarditis and bacteraemia are devastating infections with high mortality. Gram-positive cocci are the most commonly isolated pathogens. In an era of multidrug-resistant pathogens, the evaluation of new treatment options is important. Daptomycin is a cyclic lipopeptide that is active against most of these pathogens. Furthermore, it is a bactericidal antibiotic, a factor that is frequently considered in the choice of treatment of patients with bacteraemia and endocarditis. METHODS: We performed a systematic review of the evidence for the effectiveness of daptomycin in the treatment of patients and animals with endocarditis and/or bacteraemia. We searched PubMed and Scopus databases for relevant studies. Case reports, case series, controlled trials, randomized controlled trials and comparative studies using experimental animal models were included. RESULTS: The most reliable information comes from the single multicentre randomized controlled trial conducted on this issue, which showed that daptomycin is a promising antibiotic for the treatment of patients with Staphylococcus aureus bacteraemia and endocarditis. The experimental models indicate that the combination of daptomycin with rifampicin or gentamicin can improve outcomes further. Finally, in several of the published relevant case reports daptomycin was administered in patients with haematological malignancies. CONCLUSIONS: Daptomycin is a promising antibiotic that has been already approved for the treatment of patients with right-sided endocarditis and bacteraemia. However, the available clinical evidence is limited and further evaluation of the antibiotic is warranted. The commonly reported de novo development of resistance is a major concern that may limit its use. More controlled trials are needed, especially for patients infected with multidrug-resistant Gram-positive cocci, comparing daptomycin with other available treatment options, including glycopeptides and oxazolidinones.     

Clinical efficacy,cost analysis and patient acceptability of outpatient parenteral antibiotic therapy (OPAT): a decade of Sheffield (UK) OPAT service

Outpatient parenteral antimicrobial therapy (OPAT) has evolved relatively slowly in the UK. This study describes the OPAT service based in a large UK teaching hospital in Sheffield, and examines the clinical efficacy, patient acceptability and costs saved over a 10-year period. Data on 3812 episodes of OPAT administered between January 2006 and January 2016 were retrieved from a prospectively maintained electronic database. This study compared the real costs of the OPAT service with estimated costs of conventional inpatient care for these patient episodes, and analysed patient feedback questionnaires that were administered randomly between January 2014 and January 2015. A wide range of infections were managed during the 10-year period. Skin and soft tissue infections accounted for 57% of OPAT episodes. The total number of bed-days saved was 49,854. A successful outcome (cure or improvement) was found in 3357 (88%) episodes. Re-admission occurred in 265 (7%) episodes. The rates of healthcare-associated infections were low: 15 intravenous-line-related infections were recorded (0.3 per 1000 OPAT patient-days). Patient acceptance and satisfaction with OPAT were high. OPAT cost 15%, 39%, 40% and 44% of inpatient costs for an infectious diseases unit, national average costs, other departments (non-infectious diseases unit), and the minimum national average costs for each diagnostic category, respectively. This study shows that OPAT is safe, clinically efficacious and acceptable for treating a wide range of infections with high levels of patient satisfaction and substantial cost savings.     

Candida albicans versus non-albicans bloodstream infection in patients in a tertiary hospital: an analysis of microbiological data

Considerable changes in the relative frequency of systemic infections due to various Candida species as well as their in vitro susceptibility patterns have been noted in several parts of the world. We performed an analysis of microbiological data of patients with candidaemia at the University general (tertiary) hospital of Heraklion, Greece. During the study period (March 2001 to July 2006) 140 patients had candidaemia. Among them, 64/140 (46%) had candidaemia due to C. albicans and 76/140 (54%) due to non-albicans species (19/76, 25%, C. glabrata; 30/76, 40%, C. tropicalis; 20/76, 26%, C. parapsilosis; 2/76, 3%, C. lusitaniae; 3/76, 4%, C. krusei; and 2/76, 3%, C. guilliermondii). 75 isolates were tested for in vitro susceptibility to antifungal agents with E-test. No isolate was found to be resistant to amphotericin. From 34 C. albicans isolates, 5 (15%) were not susceptible to itraconazole, and 1 (3%) to fluconazole. The C. guilliermondii and the C. lusitaniae isolates were not susceptible to itraconazole. All 11 C. glabrata isolates were not susceptible to ketoconazole and itraconazole, with only 5 (45%) to fluconazole. In line with results of other relevant studies, we documented that a considerable proportion of Candida bloodstream infections were due to non-albicans Candida species.     

Outpatient parenteral antimicrobial therapy (OPAT) in the UK: a cross-sectional survey of acute hospital trusts and health boards

This study reviews the current OPAT service provision in the UK and evaluates concordance with the national OPAT practice guidelines (standards of care). We conducted a survey of acute hospital trusts and health boards in the UK regarding OPAT practices between June and September 2017. 165 (93%) of the 178 acute hospital trusts/health boards that were contacted responded to the survey. 100 (61%) indicated they had an OPAT service. Ten (10%) OPAT services did not involve an infection specialist. Bone and joint infections, and skin and soft-tissue infections were the most common conditions treated. Most OPAT services (74%) hold weekly multidisciplinary meetings/virtual ward rounds to review patient's progress. 73% had a dedicated OPAT database. We identified variations in practice and concordance with the national OPAT good practice guidelines. In an era of increasing demand for home-based care, further studies are required to identify the optimal configuration of OPAT services with regards to quality and patient safety.