Emerging drugs for the treatment of clostridium difficile

Is there a role for intestinal sporobiota in the antimicrobial resistance crisis?

Antimicrobial resistance (AMR) is a complex issue requiring specific, multi-sectoral measures to slow its spread. When people are exposed to antimicrobial agents, it can cause resistant bacteria to increase. This means that the use, misuse, and excessive use of antimicrobial agents exert selective pressure on bacteria, which can lead to the development of "silent" reservoirs of antimicrobial resistance genes. These genes can later be mobilized into pathogenic bacteria and contribute to the spread of AMR. Many socioeconomic and environmental factors influence the transmission and dissemination of resistance genes, such as the quality of healthcare systems, water sanitation, hygiene infrastructure, and pollution. The sporobiota is an essential part of the gut microbiota that plays a role in maintaining gut homeostasis. However, because spores are highly transmissible and can spread easily, they can be a vector for AMR. The sporobiota resistome, particularly the mobile resistome, is important for tracking, managing, and limiting the spread of antimicrobial resistance genes among pathogenic and commensal bacterial species.

Metagenomics and metabolomics approaches in the study of Candida albicans colonization of host niches: a framework for finding microbiome-based antifungal strategies

In silico and experimental approaches have allowed an ever-growing understanding of the interactions within the microbiota. For instance, recently acquired data have increased knowledge of the mechanisms that support, in the gut and vaginal microbiota, the resistance to colonization by Candida albicans, an opportunistic fungal pathogen whose overgrowth can initiate severe infections in immunocompromised patients. Here, we review how bacteria from the microbiota interact with C. albicans. We show how recent OMICs-based pipelines, using metagenomics and/or metabolomics, have identified bacterial species and metabolites modulating C. albicans growth. We finally discuss how the combined use of cutting-edge OMICs-based and experimental approaches could provide new means to control C. albicans overgrowth within the microbiota and prevent its consequences.

Inflammatory bowel disease and Clostridium difficile infection: clinical presentation, diagnosis, and management

As a frequent complication of inflammatory bowel disease (IBD), Clostridium difficile infection (CDI) was confirmed to not only aggravate the symptoms of IBD but also result in unexpected outcomes, including death. With the increasing prevalence rate of IBD and the updating of CDI diagnosis, the incidence of CDI in IBD patients is also seen rising. Although a detection method consisting of glutamate dehydrogenase immunoassay or nucleic acid amplification test and then toxin A/B enzyme immunoassay was recommended and widely adopted, the diagnosis of CDI in IBD is still a challenge because of the overlap between the symptoms of CDI in IBD and CDI itself. Vancomycin and fidaxomicin are the first-line therapy for CDI in IBD; however, the treatment has different effects due to the complexity of IBD patients' conditions and the choice of different treatment schemes. Although the use of fecal microbial transplantation is now in the ascendant for IBD management, the prospects are still uncertain and the prevention and treatment of the recurrence of CDI in IBD remain a clinical challenge. In this paper, the epidemiology, pathophysiology, clinical manifestation, prevention, and therapy of CDI in IBD were summarized and presented.

The Urgent Threat of Clostridioides difficile Infection: A Glimpse of the Drugs of the Future, with Related Patents and Prospects

Clostridioides difficile infection (CDI) is an urgent threat and unmet medical need. The current treatments for CDI are not enough to fight the burden of CDI and recurrent CDI (r-CDI). This review aims to highlight the future drugs for CDI and their related patented applications. The non-patent literature was collected from PubMed and various authentic websites of pharmaceutical industries. The patent literature was collected from free patent databases. Many possible drugs of the future for CDI, with diverse mechanisms of action, are in development in the form of microbiota-modulating agents (e.g., ADS024, CP101, RBX2660, RBX7455, SYN-004, SER-109, VE303, DAV132, MET-2, and BB128), small molecules (e.g., ridinilazole, ibezapolstat, CRS3123, DNV3837, MGB-BP-3, alanyl-L-glutamine, and TNP-2198), antibodies (e.g., IM-01 and LMN-201), and non-toxic strains of CD (e.g., NTCD-M3). The development of some therapeutic agents (e.g., DS-2969b, OPS-2071, cadazolid, misoprostol, ramoplanin, KB109, LFF571, and Ramizol) stopped due to failed clinical trials or unknown reasons. The patent literature reveals some important inventions for the existing treatments of CDI and supports the possibility of developing more and better CDI-treatment-based inventions, including patient-compliant dosage forms, targeted drug delivery, drug combinations of anti-CDI drugs possessing diverse mechanisms of action, probiotic and enzymatic supplements, and vaccines. The current pipeline of anti-CDI medications appears promising. However, it will be fascinating to see how many of the cited are successful in gaining approval from drug regulators such as the US FDA and becoming medicines for CDI and r-CDI.

The Gut in Heart Failure: Current Knowledge and Novel Frontiers

Heart failure (HF) represents a major health problem affecting millions of people worldwide. In the latest years, many efforts have been made to search for more effective strategies to prevent and modify the course of this disease, but results are still not satisfying. HF represents a complex clinical syndrome involving many other systems, including the gastrointestinal system. Although the relationship between the gut and HF is far from being fully understood, based on recent evidence highlighting the putative role of the gastrointestinal system in different cardiovascular diseases, it is conceivable that the gut-heart link may represent the basis for novel therapeutic approaches in the HF context as well. This intricate interplay involving typical hemodynamic changes and their consequences on gut morphology, permeability, and function, sets the stage for alterations in microbiota composition and is able to impact mechanisms of HF through different routes such as bacterial translocation and metabolic pathways. Thus, the modulation of the gut microbiota through diet, probiotics, and fecal transplantation has been suggested as a potential therapeutic approach. More interestingly, another effect of alteration in microbiota composition reflects in the upregulation of cotransporters (NHE3) with consequent salt and fluid overload and worsening visceral congestion. Therefore, the inhibitors of this cotransporter may also represent a novel therapeutic frontier. By review of recent data on this topic, we describe the current state of the complex interplay between the gastrointestinal and cardiac systems in HF, and the relevance of this knowledge in seeking new therapeutic strategies.

Benzyl and benzoyl benzoic acid inhibitors of bacterial RNA polymerase-sigma factor interaction

Transcription is an essential biological process in bacteria requiring a core enzyme, RNA polymerase (RNAP). Bacterial RNAP is catalytically active but requires sigma (σ) factors for transcription of natural DNA templates. σ factor binds to RNAP to form a holoenzyme which specifically recognizes a promoter, melts the DNA duplex, and commences RNA synthesis. Inhibiting the binding of σ to RNAP is expected to inhibit bacterial transcription and growth. We previously identified a triaryl hit compound that mimics σ at its major binding site of RNAP, thereby inhibiting the RNAP holoenzyme formation. In this study, we modified this scaffold to provide a series of benzyl and benzoyl benzoic acid derivatives possessing improved antimicrobial activity. A representative compound demonstrated excellent activity against Staphylococcus epidermidis with minimum inhibitory concentrations reduced to 0.5 μg/mL, matching that of vancomycin. The molecular mechanism of inhibition was confirmed using biochemical and cellular assays. Low cytotoxicity and metabolic stability of compounds demonstrated the potential for further studies.

Screening of Natural Products and Approved Oncology Drug Libraries for Activity against Clostridioides difficile

Clostridioides difficile is the most common cause of healthcare-associated diarrhea. Infection of the gastrointestinal tract with this Gram-positive, obligate anaerobe can lead to potentially life-threatening conditions in the antibiotic-treated populace. New therapeutics are urgently needed to treat this infection and prevent its recurrence. Here, we screened two libraries from the National Cancer Institute, namely, the natural product set III library (117 compounds) and the approved oncology drugs set V library (114 compounds), against C. difficile. In the two libraries screened, 17 compounds from the natural product set III library and 7 compounds from the approved oncology drugs set V library were found to exhibit anticlostridial activity. The most potent FDA-approved drugs (mitomycin C and mithramycin A) and a promising natural product (aureomycin) were further screened against 20 clinical isolates of C. difficile. The anticancer drugs, mitomycin C (MIC₅₀ = 0.25 μg/ml) and mithramycin A (MIC₅₀ = 0.015 μg/ml), and the naturally derived tetracycline derivative, aureomycin (MIC₅₀ = 0.06 μg/ml), exhibited potent activity against C. difficile strains. Mithramycin A and aureomycin were further found to inhibit toxin production by this pathogen. Given their efficacy, these compounds can provide a quick supplement to current treatment to address the unmet needs in treating C. difficile infection and preventing its recurrence.

International consensus conference on stool banking for faecal microbiota transplantation in clinical practice

Although faecal microbiota transplantation (FMT) has a well-established role in the treatment of recurrent Clostridioides difficile infection (CDI), its widespread dissemination is limited by several obstacles, including lack of dedicated centres, difficulties with donor recruitment and complexities related to regulation and safety monitoring. Given the considerable burden of CDI on global healthcare systems, FMT should be widely available to most centres.Stool banks may guarantee reliable, timely and equitable access to FMT for patients and a traceable workflow that ensures safety and quality of procedures. In this consensus project, FMT experts from Europe, North America and Australia gathered and released statements on the following issues related to the stool banking: general principles, objectives and organisation of the stool bank; selection and screening of donors; collection, preparation and storage of faeces; services and clients; registries, monitoring of outcomes and ethical issues; and the evolving role of FMT in clinical practice,Consensus on each statement was achieved through a Delphi process and then in a plenary face-to-face meeting. For each key issue, the best available evidence was assessed, with the aim of providing guidance for the development of stool banks in order to promote accessibility to FMT in clinical practice.

Multidrug resistance in anaerobes

Multidrug resistance (MDR) in anaerobes is not a well-known topic. Bacteroides fragilis group isolates have numerous resistance determinants such as multidrug efflux pumps, cfiA and nimB genes and activating insertion sequences, and some isolates exhibited extensive drug-resistant patterns. MDR rates in B. fragilis group were from 1.5 to >18% and up to >71% in cfiA and nimB positive isolates carrying insertion sequences. MDR was present in >1/2 of Clostridioides difficile isolates, most often in epidemic/hypervirulent strains and unusually high metronidazole or vancomycin resistance has been reported in single studies. MDR was found in Prevotella spp. (in ≤10% of isolates), Finegoldia magna, Veillonella spp. and Cutibacterium acnes. Resistance in the anaerobes tends to be less predictable and anaerobic microbiology is required in more laboratories. New hopes may be new antibiotics such as eravacycline, cadazolid, surotomycin, ridinilazol or C. difficile toxoid vaccines; however, more efforts are needed to track the MDR in anaerobes.