Comparing the efficacy and safety of faecal microbiota transplantation with bezlotoxumab in reducing the risk of recurrent Clostridium difficile infections: a systematic review and Bayesian network meta-analysis of randomised controlled trials

Assessing Galleria mellonella as a preliminary model for systemic Staphylococcus aureus infection: Evaluating the efficacy and impact of vancomycin and Nigella sativa oil on gut microbiota

Background

Staphylococcus aureus is a Gram-positive bacterium that can cause various infections. The Galleria mellonella has been used as a preliminary test for infection model. The study aimed to evaluate the effectiveness of G. mellonella as a microbiome model and compare the efficacy of vancomycin and antimicrobial activity of Nigella sativa (NS) on the gut flora.

Methods

G. mellonella larvae were subjected to metagenomic analysis. The larvae's guts were collected, homogenized in phosphate-buffered saline (PBS), and the gut contents isolated for bacterial DNA extraction. Larvae were assigned into the following groups: negative control (PBS only); positive control (MRSA only); vancomycin treated group; NS oil treated group and combination (vancomycin and NS oil) treated group. Larvae were cultured, inoculated with S. aureus, and treated with vancomycin and NS oil. Larval activity, cocoon formation, growth, melanization, and survival were monitored. The toxicity of vancomycin and NS oil was tested, and S. aureus burden and natural microbiota were determined. Hemocyte density was measured. Statistical analysis was conducted using R.

Results

Enterococcus related species dominated approximately 90 % of the gastrointestinal tract of the larvae. The survival rate following treatment was 85 % with vancomycin, 64 % with NS oil, and 73 % with a combination of both. The count of Enterococcus Colony Forming Units (CFUs) was significantly lower in the vancomycin treatment group (8.14E+04) compared to those treated with NS oil (1.97E+06) and the combination treatment (8.95E+05). Furthermore, the S. aureus burden was found to be lower in the NS oil (1.04E+06) and combination treatment groups (9.02E+05) compared to the vancomycin treatment group (3.38E+06). Hemocyte densities were significantly higher in the NS oil (8.29E+06) and combination treatment groups (8.18E+06) compared to the vancomycin treatment group (4.89E+06).

Conclusions

The study supported the use of G. mellonella model as a preliminary test to assess the effect of different antimicrobials against S. aureus and gut microbiota. NS oil showed more selectivity against S. aureus and protectiveness for the natural Enterococcus gut flora.

The Efficacy of Bezlotoxumab in the Prevention of Recurrent Clostridium difficile: A Systematic Review

Clostridium difficile infection (CDI) is the most common nosocomial infection in hospitals. Despite the fact that CDI has treatment options, recurrence is common after the treatment, recurrence will occur in approximately 20%-35% of people initially affected, with 40%-60% of these having a second recurrence. Patients are more likely to have several recurrences after the second, which can lead to antibiotic overuse, and as a result, CDI-related health care expenses, hospitalizations, and mortality are on the rise. The first treatment to receive Food and Drug Administration (FDA) approval for the prevention of C. difficile recurrence is bezlotoxumab, a novel human monoclonal antibody against C. difficile toxin B. In the present systematic review, we assessed various studies from PubMed, PubMed Central (PMC), Google Scholar, and Science direct that evaluated the efficacy of bezlotoxumab in the prevention of recurrent C. difficile (rCDI), and we also briefly discussed the pathophysiology of C. difficile and the risk factors for recurrence of C. difficile. The major MODIFY trial has proven the efficacy, pooled analysis of MODIFY 1 AND 2 trials demonstrated the following results as compared to placebo (bezlotoxumab: 129/781 [16.5] placebo:206/773 [26.6] -10.0% [95% CI -14.0 to -6.0], p<0.0001) with number needed to treat (NNT) of 10. All other observational studies also showed a positive response with bezlotoxumab in the prevention of C. difficile. In conclusion, bezlotoxumab is a great option adjunctive with standard of care CDI antibiotics for the prevention of rCDI in high-risk adults.

Fecal microbiota transplantation for recurrent Clostridioides difficile, safety, and pitfalls

Clostridioides difficile infection (CDI) is one of the leading causes of hospital-acquired infection attributing to substantial morbidity, mortality, and healthcare cost. Recurrent CDI (rCDI) is common and occurs after effective treatment of first episode. Treatment of rCDI is based on accurate diagnoses, due to difficulty in distinguishing between colonization of C. difficile spores or CDI; coronavirus disease 2019 (COVID-19) added to the complexity of diagnoses as both entities can co-occur. It is difficult to eradicate rCDI, and there remains a critical gap regarding treatment of rCDI. The treatment goal of rCDI is to reestablish normal microbiota. Fecal microbiota transplantation (FMT) is suggested as a treatment for second episode of rCDI. Based on the collective evidence of all randomized controlled trials, FMT was reported more efficacious compared with vancomycin or fidaxomicin; however, these trials had limited number of patients and all patients were pre-treated with vancomycin prior to FMT. Furthermore, when comparing various routes of instillation and types of preparation of fecal microbiota, no difference was observed in cure rate. Despite the success rate of FMT, there remains a concern for transmission of infectious agents, such as Gram negative bacteremia or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), adverse events (diarrhea and abdominal pain), and reports of new diagnoses (inflammatory bowel disease, weight gain and irritable bowel syndrome). To lessen the risk of transmissible infections, donor screening should be performed, which includes screening for medical comorbidities and infectious pathogens in blood and feces. Scheduling complexities and reimbursement places an additional roadblock for using FMT. Microbiome-based therapies are being developed to eliminate the logistical challenges related to FMT. Large prospective and placebo-controlled studies are needed to evaluate the efficacy and long-term safety of FMT, so its use can be justified in clinical practice.

Regulating antimicrobial sales in Saudi Arabia: Achievements and challenges

BACKGROUND

Antimicrobials save millions of lives annually from dying because of bacterial infections, but the rapid emergence of antimicrobial resistance (AMR) becomes a global threat. The Saudi Ministry of Health (MOH) has taken containment measures to limit the misuse of antimicrobials via implementing restrictions on dispensing without prescriptions. Hence, we aim to evaluate the impact of regulating antimicrobial sales and identify challenges that pharmacists are facing to prevent self-medication with antimicrobial agents.

MATERIALS AND METHODS

A cross-sectional study was conducted using two sources of data: sales reports from 3000 pharmacies in Saudi Arabia and a self-designed questionnaire. The questionnaire consists of 24 items written in English and Arabic languages, went through multiple steps to ensure validity and reliability and then distributed online. Descriptive analyses were used to present the results.

RESULTS

A total of 106 pharmacists completed the questionnaire. Sixty-three per cent of the respondents observed a reduction of 40% in sales, which was consistent with pharmacies' sales reports, which revealed a 50% reduction in 2018 as compared to 2017. Seventy-six per cent of respondents agreed that antimicrobials' sales restrictions were frustrating to patients. The percentage of pharmacists who reported receiving prescriptions with complete information about patients, prescribers, medications and issue date was 70%, 54%, 86% and 77%, respectively. And 69% of respondents revealed receiving support from their employers to prevent dispensing antimicrobial agents without prescription.

CONCLUSION

Restriction measures implemented by the Saudi MOH led to a 40% to 50% reduction in inappropriate sales of antimicrobials. Further studies are needed to investigate the methods for improving documentation and prescribing practices.

Microbiota-based Therapies Clostridioides difficile infection that is refractory to antibiotic therapy

Clostridioides difficile infection (CDI) has had a devastating impact worldwide with significant rates of mortality, especially among the elderly. Despite effective antibiotics, the incidence of recurrent CDI (rCDI) is increasing and more difficult to treat with antibiotics alone. Fecal Microbiota Transplantation (FMT) has emerged as a consistently effective treatment for rCDI. Mechanisms for FMT are not entirely understood, but remain an area of active investigation. There have been recent safety reports with the use of FMT regarding transmission of pathogens in a few patients that have led to serious illness. With appropriate screening, FMT can be safely administered and continue to have a significant impact on eradication of rCDI and improve the lives of patients suffering from this disease. In this review, we summarize current treatments for CDI with a focus on microbiota-based therapies used for antibiotic refractory disease.

Fecal Microbiota Transplantation May Be the Best Option in Treating Multiple Clostridioides difficile Infection: A Network Meta-Analysis

Introduction

Clostridioides difficile (formerly Clostridium) infection (CDI) is the most common cause of healthcare-associated diarrhea with high mortality and recurrence rate; furthermore, the treatment of recurrent cases is a challenge. In this network meta-analysis, we aimed to compare all available therapies against multiple recurrent CDI (mrCDI) and rank them by efficacy.

Methods

After a systematic search, randomized controlled trials (RCT) with any interventions against mrCDI were included. Data were extracted to the study database using Excel. Risk of bias assessment was performed with the Cochrane RoB 2 tool. The primary outcome was the clinical cure of CDI and the secondary outcome was the recurrence of CDI. A Bayesian method was performed to investigate the efficacy rank order of therapies. We registered our protocol with the Prospero Center for Reviews and Dissemination (registration no. CRD42020160365).

Results

Six RCTs with seven interventions were included in the quantitative synthesis. According to the surface under the cumulative ranking curve values, fecal microbiota transplantation (FMT) after a short course of vancomycin therapy (83%) shows the highest efficacy for clinical cure. Tolevamer and vancomycin + FMT seemed to be the most effective in preventing recurrence (87% and 75%, respectively).

Conclusion

Vancomycin + FMT is perhaps the most effective option for the treatment and prevention of mrCDI, while tolevamer is also effective in preventing recurrence.

Electronic Supplementary Material

The online version of this article (10.1007/s40121-020-00356-9) contains supplementary material, which is available to authorized users.

Clostridioides difficile infections in Saudi Arabia: Where are we standing?

Clostridioides difficile infections (CDIs) are infamous healthcare-associated infections for causing watery diarrhea to long-term hospitalized patients with a high mortality rate. Epidemiological reports from western countries showed up-trending pattern in the number of CDIs cases. It is becoming immensely challenging for routine diagnostic protocols to detect CDIs accurately with short turnaround time. In Saudi Arabia, there is a paucity of data about CDIs’ prevalence, recurrence rate, methods of screening and mortality rate. Nevertheless, a growing number of cases with similar virulence strains and comparable antibiotic resistance pattern to the western countries counterparts reported data were also detected. This review aims to present the status of CDIs’ diagnosis and incidence rate in Saudi Arabia based on current literature.

Bezlotoxumab for Preventing Recurrent Clostridioides difficile Infection: A Narrative Review from Pathophysiology to Clinical Studies

Clostridioides difficile infection (CDI) and recurrent CDI (rCDI) remain associated with a reduction in the patients’ quality of life and with increased healthcare costs. Bezlotoxumab is a monoclonal antibody against toxin B of C. difficile, approved for prevention of rCDI. In this narrative review, we briefly discuss the pathophysiology of CDI and the mechanism of action of bezlotoxumab, as well as the available evidence from investigational and observational studies in terms of efficacy, effectiveness, and safety of bezlotoxumab for the prevention of rCDI. Overall, bezlotoxumab has proved efficacious in reducing the burden of rCDI, thereby providing clinicians with an important novel strategy to achieve sustained cure. Nonetheless, experiences outside randomized controlled trials (RCTs) remain scant, and mostly represented by case series without a control group. Along with the conduction of RCTs to directly compare bezlotoxumab with faecal microbiota transplantation (or to precisely evaluate the role of their combined use), further widening our post-marketing experience remains paramount to firmly guide the use of bezlotoxumab outside RCTs, and to clearly identify those real-life settings where its preventive benefits can be exploited most.

Regulation, risk and safety of Faecal Microbiota Transplant

From its origins as a left-field, experimental, and even “maverick” intervention, faecal microbiota transplantation (FMT) is now a well-recognised, accepted, and potentially life-saving therapeutic strategy, for the management of recurrent Clostridiodes difficile infection (rCDI). It is being investigated as a treatment for a growing number of diseases including hepatic encephalopathy and eradication of antimicrobial resistant organisms, and the list of indications will likely expand in the future.

There is no universally accepted definition of what FMT is, and its mechanism of action remains incompletely understood; this has likely contributed to the breadth of approaches to regulation depending on interpretation. In the UK FMT is considered a medicinal product, in North America, a biological product, whereas in parts of Europe, it is considered a human cell/tissue product. Regulation seeks to improve quality and safety, however, lack of standardisation creates confusion, and overly restrictive regulation may hamper widespread access and discourage research using FMT.

FMT is generally considered safe, especially if rigorous donor screening and testing is conducted. Most short-term risks are associated with the delivery method (e.g. colonoscopy). Longer term risks are less well described but longitudinal follow-up of treated cohorts is in place to assess for this, and no signal towards harm has been found to date. Rarely it has been associated with adverse outcomes including the transmission of antibiotic resistant bacteria, and even death.

It is vital patients undergoing FMT are well informed to the currently appreciated risks and benefits before proceeding.

Comparative of the Effectiveness and Safety of Biological Agents, Tofacitinib, and Fecal Microbiota Transplantation in Ulcerative Colitis: Systematic Review and Network Meta-Analysis

BACKGROUND

Biological agents are commonly used for the treatment of ulcerative colitis (UC). As new treatments, tofacitinib, and fecal microbiota transplantation (FMT) have demonstrated efficacy in treating UC. This network meta-analysis aims to determine the efficacy and safety of biological agents, tofacitinib, and FMT.

METHODS

A network meta-analysis was conducted by systematically searching the PubMed, Embase, and Cochrane Libraries. According to strict inclusion and exclusion criteria, we included randomized controlled trials (RCTs) of biological agents, tofacitinib, and FMT in UC. A random-effect model was chosen by the network meta-analysis and sensitivity analysis. Heterogeneity test and publication bias test were performed to determine the efficacy of treatments.

RESULTS

Data were extracted from 16 RCTs and we found that all treatments were more effective than the placebos. A total of 21 comparisons were made to determine efficiency. We found that infliximab, vedolizumab, and FMT performed better curative effect in terms of absolute effects and relative ranks. Furthermore, there was no statistical difference in the efficacy of biological agents, tofacitinib, and FMT. Moreover, no treatments were found to increase the occurrence of adverse events when compared with placebos, except infliximab. However, vedolizumab seemed to reduce the occurrence of adverse events compared with infliximab.

CONCLUSION

Of the biological agents, vedolizumab and infliximab were the most effective, suggesting that biological agents are still a better choice. Nevertheless, tofacitinib and FMT may be promising alternatives with high efficacies. However, more safety and maintenance studies need to be conducted in future for the acquisition of more accurate results.Abbreviations: FMT: Fecal microbiota transplantation; UC: Ulcerative colitis; RCTs: Randomized controlled trials; IBD: Inflammatory bowel disease; CD: Crohn's disease; IBS: Irritable bowel syndrome; CDI: Clostridium difficile infections; ITT: Intention-to-treat; RR: Relative risk; CI: Confidence interval; CrI: Credible intervals; IFX: Infliximab; ADA: Adalimumab; TFB: Tofacitinib; GLM: Golimumab; VDZ: Vedolizumab; PBO: Placebo; wk: week; F: Female; M: Male; AEs: Adverse events; SAEs: Serious adverse events; anti-TNF: Anti-tumor necrosis factors.