Clostridium difficile infection and antibiotic-associated diarrhoea

Reevaluating human-microbiota symbiosis: Strain-level insights and evolutionary perspectives across animal species

The prevailing consensus in scientific literature underscores the mutualistic bond between the microbiota and the human host, suggesting a finely tuned coevolutionary partnership that enhances the fitness of both parties. This symbiotic relationship has been extensively studied, with certain bacterial attributes being construed as hallmarks of natural selection favoring the benefit of the human host. Some scholars go as far as equating the intricate interplay between humans and their intestinal microbiota to that of endosymbiotic relationships, even conceptualizing microbiota as an integral human organ. However, amidst the prevailing narrative of bacterial species being categorized as beneficial or detrimental to human health, a critical oversight often emerges - the inherent functional diversity within bacterial strains. Such reductionist perspectives risk oversimplifying the complex dynamics at play within the microbiome. Recent genomic analysis at the strain level is highly limited, which is surprising given that strain information provides critical data about selective pressures in the intestine. These pressures appear to focus more on the well-being of bacteria rather than human health. Connected to this is the extent to which animals depend on metabolic activity from intestinal bacteria, which varies widely across species. While omnivores like humans exhibit lower dependency, certain herbivores rely entirely on bacterial activity and have developed specialized compartments to house these bacteria.

Impact of Extended Prophylactic Antibiotics on Risk of Prosthetic Joint Infection in Primary Total Hip Arthroplasty: A Matched Cohort Analysis

BACKGROUND

Extended oral prophylactic antibiotics have been increasingly used in arthroplasty with the goal of reducing the risk of prosthetic joint infection (PJI). While a reduction in the rate of PJI has been noted with extended oral antibiotic regimens in high-risk patients, no large database study has assessed infection risk after primary total hip arthroplasty among well-balanced cohorts receiving and not receiving postoperative extended oral antibiotics.

METHODS

A retrospective cohort study was conducted using a national database, TriNetX, to identify patients who underwent primary total hip arthroplasty. This cohort was stratified by oral antibiotic prescription within one day of procedure. A one-to-one propensity score matching based on age, sex, class of obesity, and medical comorbidities was conducted. Outcomes explored in this study were 90-day risk of PJI, superficial skin infection, deep skin infection, and all-cause revision.

RESULTS

90-day postoperative infection complications of PJI were higher in the group receiving antibiotics (hazard ratio: 1.83, P -value = 0.012). Other complications such as superficial skin infection, deep skin infection, and all-cause revision showed no statistically significant differences.

CONCLUSION

This database analysis of 5,476 patients demonstrated no decrease in complications of PJI, superficial or deep skin infection, or revision at 90 days. Future randomized controlled trials are needed to evaluate the efficacy of extended oral antibiotics.

LEVEL OF EVIDENCE

III.

Exploring novel microbial metabolites and drugs for inhibiting Clostridioides difficile

Clostridioides difficile is an enteric pathogen that can cause a range of illnesses from mild diarrhea to pseudomembranous colitis and even death. This pathogen often takes advantage of microbial dysbiosis provoked by antibiotic use. With the increasing incidence and severity of infections, coupled with high recurrence rates, there is an urgent need to identify innovative therapies that can preserve the healthy state of the gut microbiota. In this study, we screened a microbial metabolite library against C. difficile. From a collection of 527 metabolites, we identified 18 compounds with no previously identified antimicrobial activity and metabolites that exhibited potent activity against C. difficile growth. Of these 18 hits, five drugs and three metabolites displayed the most potent anti-C. difficile activity and were subsequently assessed against 20 clinical isolates of C. difficile. These potent agents included ecteinascidin 770 (minimum inhibitory concentration against 50% of isolates [MIC50] ≤0.06 µg/mL); 8-hydroxyquinoline derivatives, such as broxyquinoline and choloroquinaldol (MIC50 = 0.125 µg/mL); ionomycin calcium salt, carbadox, and robenidine hydrochloride (MIC50 = 1 µg/mL); and dronedarone and milbemycin oxime (MIC50 = 4 µg/mL). Unlike vancomycin and fidaxomicin, which are the standard-of-care anti-C. difficile antibiotics, most of these metabolites showed robust bactericidal activity within 2-8 h with minimal impact on the growth of representative members of the normal gut microbiota. These results suggest that the drugs and microbial metabolite scaffolds may offer alternative avenues to address unmet needs in C. difficile disease prevention and treatment.

IMPORTANCE

The most frequent infection associated with hospital settings is Clostridioides difficile, which can cause fatal diarrhea and severe colitis, toxic megacolon, sepsis, and leaky gut. Those who have taken antibiotics for other illnesses that affect the gut's healthy microbiota are more susceptible to C. difficile infection (CDI). Recently, some reports showed higher recurrence rates and resistance to anti-C. difficile, which may compromise the efficacy of CDI treatment. Our study is significant because it is anticipated to discover novel microbial metabolites and drugs with microbial origins that are safe for the intestinal flora, effective against C. difficile, and reduce the risk of recurrence associated with CDI.

The Clinical and Economic Burden of Antibiotic Use in Pediatric Patients With Varicella Infection: A Retrospective Cohort Analysis of Real-World Data in England

BACKGROUND

Varicella is a highly infectious disease, particularly affecting children, that can lead to complications requiring antibiotics or hospitalization. Antibiotic use for varicella management is poorly documented. This study assessed antibiotic use for varicella and its complications in a pediatric population in England.

METHODS

Data were drawn from medical records in the Clinical Practice Research Datalink and Hospital Episode Statistics data sets. The study included patients <18 years old with varicella diagnosed during 2014-2018 and 3-month follow-up available. We determined varicella-related complications, medication use, healthcare resource utilization, and costs from diagnosis until 3 months after diagnosis.

RESULTS

We identified 114 578 children with a primary varicella diagnosis. Of these, 7.7% (n = 8814) had a varicella-related complication, the most common being ear, nose, and throat related (37.1% [n = 3271]). In all, 25.9% (n = 29 706 of 114 578) were prescribed antibiotics. A higher proportion of patients with complications than without complications were prescribed antibiotics (64.3% [n = 5668 of 8814] vs 22.7% [n = 24 038 of 105 764]). Mean annualized varicella-related costs were £2 231 481 for the study cohort. Overall, antibiotic prescriptions cost approximately £262 007.

CONCLUSIONS

This study highlights high antibiotic use and healthcare resource utilization associated with varicella management, particularly in patients with complications. A national varicella vaccination program in England may reduce varicella burden and related complications, medication use, and costs.

Characterization of Clostridioides difficile Persister Cells and Their Role in Antibiotic Tolerance

Clostridioides difficile is a Gram-positive pathogen known for its toxin production and spore formation. It is primarily responsible for most cases of antibiotic-associated diarrhea. Bacterial persisters are a small subset of the population that exhibits transient tolerance to bactericidal substances, and they are of significant medical concern due to their association with the emergence of antibiotic resistance and difficult-to-treat chronic or recurrent infections. Vancomycin, the predominant antibiotic utilized in the management of C. difficile infection, is extensively applied in the realm of clinical practice. Previous studies have demonstrated a persister-like phenotype with treatments involving this antibiotic. However, the mechanism in C. difficile remains largely unknown, primarily due to the challenge of isolating this small population at any given time. To better characterize C. difficile persister cells, we present a study that enables the enrichment and characterization of persister cells from bacterial cultures in both the exponential and stationary phases. Moreover, we could differentiate between triggered (induced using antibiotics such as vancomycin) and spontaneous (stochastic) persister cells. Additionally, we observed the involvement of toxin-antitoxin systems and Clp proteases in persister cell formation.

The burden of infectious diseases throughout and after the COVID-19 pandemic (2020-2023) and Russo-Ukrainian war migration

Understanding how the infectious disease burden was affected throughout the COVID-19 pandemic is pivotal to identifying potential hot spots and guiding future mitigation measures. Therefore, our study aimed to analyze the changes in the rate of new cases of Poland's most frequent infectious diseases during the entire COVID-19 pandemic and after the influx of war refugees from Ukraine. We performed a registry-based population-wide study in Poland to analyze the changes in the rate of 24 infectious disease cases from 2020 to 2023 and compared them to the prepandemic period (2016-2019). Data were collected from publicly archived datasets of the Epimeld database published by national epidemiological authority institutions. The rate of most of the studied diseases (66.6%) revealed significantly negative correlations with the rate of SARS-CoV-2 infections. For the majority of infectious diseases, it substantially decreased in 2020 (in case of 83%) and 2021 (63%), following which it mostly rebounded to the prepandemic levels and, in some cases, exceeded them in 2023 when the exceptionally high annual rates of new cases of scarlet fever, Streptococcus pneumoniae infections, HIV infections, syphilis, gonococcal infections, and tick-borne encephalitis were noted. The rate of Clostridioides difficile enterocolitis was two-fold higher than before the pandemic from 2021 onward. The rate of Legionnaires' disease in 2023 also exceeded the prepandemic threshold, although this was due to a local outbreak unrelated to lifted COVID-19 pandemic restrictions or migration of war refugees. The influx of war migrants from Ukraine could impact the epidemiology of sexually transmitted diseases. The present analysis indicates that continued efforts are needed to prevent COVID-19 from overwhelming healthcare systems again and decreasing the control over the burden of other infectious diseases. It also identifies the potential tipping points that require additional mitigation measures, which are also discussed in the paper, to avoid escalation in the future.

Next generation probiotics: Engineering live biotherapeutics

The population dynamics of the human microbiome have been associated with inflammatory bowel disease, cancer, obesity, autoimmune diseases, and many other human disease states. An emerging paradigm in treatment is the administration of live engineered organisms, also called next-generation probiotics. However, the efficacy of these microbial therapies can be limited by the organism's overall performance in the harsh and nutrient-limited environment of the gut. In this review, we summarize the current state of the art use of bacterial and yeast strains as probiotics, highlight the recent development of genetic tools for engineering new therapeutic functions in these organisms, and report on the latest therapeutic applications of engineered probiotics, including recent clinical trials. We also discuss the supplementation of prebiotics as a method of manipulating the microbiome and improving the overall performance of engineered live biotherapeutics.

The challenges of implementing infection prevention and antimicrobial stewardship programs in resource-constrained settings

The burden of healthcare-associated infections (HAIs) and antimicrobial resistance (AMR) is disproportionately high in low and middle-income countries. Barriers to implementing effective antimicrobial stewardship and infection prevention programs include the lack of a structural framework, consensus guidelines, educational opportunities, trained personnel, funding, and access to resources such as manpower, information technology, and diagnostics. Socioeconomic instability with supply chain interruptions, poor skilled staff retention, absence of mandates, and inadequate support to enforce existing policies further aggravates the situation. Failure to implement measures to tackle AMR and HAIs effectively will result in repercussions globally.

Antimicrobials: An update on new strategies to diversify treatment for bacterial infections

Ninety-five years after Fleming's discovery of penicillin, a bounty of antibiotic compounds have been discovered, modified, or synthesised. Diversification of target sites, improved stability and altered activity spectra have enabled continued antibiotic efficacy, but overwhelming reliance and misuse has fuelled the global spread of antimicrobial resistance (AMR). An estimated 1.27 million deaths were attributable to antibiotic resistant bacteria in 2019, representing a major threat to modern medicine. Although antibiotics remain at the heart of strategies for treatment and control of bacterial diseases, the threat of AMR has reached catastrophic proportions urgently calling for fresh innovation. The last decade has been peppered with ground-breaking developments in genome sequencing, high throughput screening technologies and machine learning. These advances have opened new doors for bioprospecting for novel antimicrobials. They have also enabled more thorough exploration of complex and polymicrobial infections and interactions with the healthy microbiome. Using models of infection that more closely resemble the infection state in vivo, we are now beginning to measure the impacts of antimicrobial therapy on host/microbiota/pathogen interactions. However new approaches are needed for developing and standardising appropriate methods to measure efficacy of novel antimicrobial combinations in these contexts. A battery of promising new antimicrobials is now in various stages of development including co-administered inhibitors, phages, nanoparticles, immunotherapy, anti-biofilm and anti-virulence agents. These novel therapeutics need multidisciplinary collaboration and new ways of thinking to bring them into large scale clinical use.

Impact of penicillin allergy labels on surgical site infections in a large UK cohort of gastrointestinal surgery patients

Objectives

Studies in the USA, Canada and France have reported higher surgical site infection (SSI) risk in patients with a penicillin allergy label (PAL). Here, we investigate the association between PALs and SSI in the UK, a country with distinct epidemiology of infecting pathogens and range of antimicrobial regimens in routine use.

Methods

Electronic health records and national SSI surveillance data were collated for a retrospective cohort of gastrointestinal surgery patients at Cambridge University Hospitals NHS Foundation Trust from 1 January 2015 to 31 December 2021. Univariable and multivariable logistic regression were used to examine the effects of PALs and the use of non-β-lactam-based prophylaxis on likelihood of SSI, 30 day post-operative mortality, 7 day post-operative acute kidney injury and 60 day post-operative infection/colonization with antimicrobial-resistant bacteria or Clostridioides difficile.

Results

Our data comprised 3644 patients and 4085 operations; 461 were undertaken in the presence of PALs (11.3%). SSI was detected after 435/4085 (10.7%) operations. Neither the presence of PALs, nor the use of non-β-lactam-based prophylaxis were found to be associated with SSI: adjusted OR (aOR) 0.90 (95% CI 0.65-1.25) and 1.20 (0.88-1.62), respectively. PALs were independently associated with increased odds of newly identified MRSA infection/colonization in the 60 days after surgery: aOR 2.71 (95% CI 1.13-6.49). Negative association was observed for newly identified infection/colonization with third-generation cephalosporin-resistant Gram-negative bacteria: aOR 0.38 (95% CI 0.16-0.89).

Conclusions

No evidence was found for an association between PALs and the likelihood of SSI in this large UK cohort, suggesting significant international variation in the impact of PALs on surgical patients.

Epidemiology of Clostridioides difficile infection at a tertiary care facility in Saudi Arabia: Results of prospective surveillance

OBJECTIVES

To determine the incidence of Clostridioides difficile infection (CDI) and the frequency of known risk factors.

METHODS

A prospective hospital-based surveillance for CDI, according to the Centers for Disease Control and Prevention criteria, was carried out from July 2019 to March 2022 for all inpatients aged more than one year in Prince Sultan Military Medical City, Riyadh, Saudi Arabia.

RESULTS

A total of 139 cases of CDI were identified during the survey among 130 patients admitted in the hospital. Most cases were incident (n=130; 93.5%), and almost three-quarters (n=102; 73.4%) were hospital-onset (HO) CDI, with an incidence rate of 1.62 per 10,000 patient days (PD). The highest rates were noted in intensive care units with an incidence rate of 3 per 10,000 PD and wards for immunocompromised patients with an incidence rate of 2.72 per 10,000 PD. The most prevalent risk factor for CDI was acid-reducing drugs (72.6%). Vancomycin (48%) and ciprofloxacin (25%) were the most frequently prescribed antibiotics for patients with CDI. Clostridioides difficile infection complications were identified in 5.7% of the cases, with a reported 28-day mortality rate of 3.8%.

CONCLUSION

In our hospital, HO-CDI incidence rate is lower than that in high-income countries. National multicenter surveillance is needed to evaluate the actual burden of CDI in Saudi Arabia.

Robust demarcation of the family Peptostreptococcaceae and its main genera based on phylogenomic studies and taxon-specific molecular markers

The family Peptostreptococcaceae, which contains 15 genera including Clostridioides, presently lacks proper circumscription. Using 52 available genomes for Peptostreptococcaceae species, we report comprehensive phylogenomic and comparative analyses to reliably discern their evolutionary relationships. In phylogenetic trees based on core genome proteins and 16S rRNA gene sequences, the examined species formed a strongly supported clade designated as Peptostreptococcaceae sensu stricto. This clade encompassed the genera Peptostreptococcus (type genus), Asaccharospora, Clostridioides, Intestinibacter, Paeniclostridium, Paraclostridium, Peptacetobacter, Romboutsia and Terrisporobacter, and two misclassified species (viz. Eubacterium tenue and 'Clostridium dakarense'). The distinctness of this clade is strongly supported by eight identified conserved signature indels (CSIs), which are specific for the species from this clade. Based on the robust evidence provided by presented studies, we are proposing the emendment of family Peptostreptococcaceae to only the genera within the Peptostreptococcaceae sensu stricto clade. We also report 67 other novel CSIs, which reliably demarcate different Peptostreptococcaceae species clades and clarify the classification of some misclassified species. Based on the consistent evidence obtained from different presented studies, we are making the following proposals to clarify the classification of Peptostreptococcaceae species: (i) transfer of Eubacterium tenue, Paeniclostridium ghonii and Paeniclostridium sordellii as comb. nov. into the genus Paraclostridium; (ii) transfer of Clostridioides mangenotii as a comb. nov. into Metaclostridioides gen. nov.; (iii) classification of 'Clostridium dakarense' as a novel species Faecalimicrobium dakarense gen. nov., sp. nov. (type strain FF1T; genome and 16S rRNA accession numbers GCA_000499525.1 and KC517358, respectively); (iv) transfer of two misclassified species, Clostridium paradoxum and Clostridium thermoalcaliphilum, into Alkalithermobacter gen. nov.; and (v) proposals for two novel families, Peptoclostridiaceae fam. nov. and Tepidibacteraceae fam. nov., to accommodate remaining unclassified Peptostreptococcaceae genera. The described CSIs specific for different families and genera provide novel and reliable means for the identification, diagnostics and biochemical studies on these bacteria.

A Real-World Study on the Clinical Characteristics, Outcomes, and Relationship between Antibiotic Exposure and Clostridioides difficile Infection

Clostridioides difficile is a Gram-positive bacteria that causes nosocomial infections, significantly impacting public health. In the present study, we aimed to describe the clinical characteristics, outcomes, and relationship between antibiotic exposure and Clostridioides difficile infection (CDI) in patients based on reports from two databases. Thus, we conducted a retrospective study of patients diagnosed with CDI from Sibiu County Clinical Emergency Hospital (SCCEH), Romania, followed by a descriptive analysis based on spontaneous reports submitted to the EudraVigilance (EV) database. From 1 January to 31 December 2022, we included 111 hospitalized patients with CDI from SCCEH. Moreover, 249 individual case safety reports (ICSRs) from EVs were analyzed. According to the data collected from SCCEH, CDI was most frequently reported in patients aged 65-85 years (66.7%) and in females (55%). In total, 71.2% of all patients showed positive medical progress. Most cases were reported in the internal medicine (n = 30, 27%), general surgery (n = 26, 23.4%), and infectious disease (n = 22, 19.8%) departments. Patients were most frequently exposed to ceftriaxone (CFT) and meropenem (MER). Also, in the EV database, most CDI-related ADRs were reported for CFT, PIP/TAZ (piperacillin/tazobactam), MER, and CPX (ciprofloxacin). Understanding the association between previous antibiotic exposure and the risk of CDI may help update antibiotic stewardship protocols and reduce the incidence of CDI by lowering exposure to high-risk antibiotics.

Helicobacter pylori Eradication Treatment in Older Patients

Helicobacter pylori is the main etiopathogenetic factor of chronic gastritis, peptic ulcer disease and gastric cancer. The world's population is shifting towards older people, who have the highest prevalence of H. pylori. Aging-related peculiarities could have an impact on the treatment of H. pylori and there is still a lack of research data in the older population. The aim of this review was to summarize the findings of the most recent information, publications and studies on the issues relating to H. pylori infection in older patients. H. pylori eradication offers gastrointestinal and extra gastrointestinal benefits in older patients. Based on the main guidelines, H. pylori should be eradicated independent of the patient's age, only reconsidering cases with terminal illness and low life expectancy. Proton pump inhibitors are generally safe and well tolerated. Some antibiotics require dose adjustment only in advanced renal insufficiency and the risk of hepatotoxicity is very low. Special precautions should be taken in patients with polypharmacy and those taking aspirin or non-steroidal anti-inflammatory drugs. In older patients, H. pylori eradication treatment frequently causes only mild and short-term adverse events; however, treatment compliance is usually still very good. H. pylori treatment in older patients does not increase the risk of Clostridium difficile infection. Optimal eradication effectiveness (> 90%) is mostly achieved with bismuth- and non-bismuth-based quadruple therapies. Susceptibility-guided treatment of H. pylori can contribute to increasing the effectiveness of eradication regimens in older adults. To achieve optimal H. pylori eradication effectiveness in older patients, the same guidelines, which are applied to adults, also apply to this population: avoiding repetitive treatment prescriptions, choosing quadruple therapies, prescribing longer treatment duration and administering high-dose proton pump inhibitors twice daily.

Orally Administered Drugs and Their Complicated Relationship with Our Gastrointestinal Tract

Orally administered compounds represent the great majority of all pharmaceutical compounds produced for human use and are the most popular among patients since they are practical and easy to self-administer. Following ingestion, orally administered drugs begin a "perilous" journey down the gastrointestinal tract and their bioavailability is modulated by numerous factors. The gastrointestinal (GI) tract anatomy can modulate drug bioavailability and accounts for interpatient drug response heterogeneity. Furthermore, host genetics is a contributor to drug bioavailability modulation. Importantly, a component of the GI tract that has been gaining notoriety with regard to drug treatment interactions is the gut microbiota, which shares a two-way interaction with pharmaceutical compounds in that they can be influenced by and are able to influence administered drugs. Overall, orally administered drugs are a patient-friendly treatment option. However, during their journey down the GI tract, there are numerous host factors that can modulate drug bioavailability in a patient-specific manner.

The anti-inflammatory and anti-apoptotic effects of Achillea millefolium L. extracts on Clostridioides difficile ribotype 001 in human intestinal epithelial cells

BACKGROUND

Clostridioides difficile infection (CDI) is one of the most common health care-acquired infections. The dramatic increase in antimicrobial resistance of C. difficile isolates has led to growing demand to seek new alternative medicines against CDI. Achillea millefolium L. extracts exhibit strong biological activity to be considered as potential therapeutic agents. In this work, the inhibitory effects of A. millefolium, its decoction (DEC) and ethanol (ETOH) extracts, were investigated on the growth of C. difficile RT001 and its toxigenic cell-free supernatant (Tox-S) induced inflammation and apoptosis.

METHODS

Phytochemical analysis of extracts was performed by HPLC and GC analysis. The antimicrobial properties of extracts were evaluated against C. difficile RT001. Cell viability and cytotoxicity of Caco-2 and Vero cells treated with various concentrations of extracts and Tox-S were examined by MTT assay and microscopy, respectively. Anti-inflammatory and anti-apoptotic effects of extracts were assessed in Tox-S stimulated Caco-2 cells by RT-qPCR.

RESULTS

Analysis of the phytochemical profile of extracts revealed that the main component identified in both extracts was chlorogenic acid. Both extracts displayed significant antimicrobial activity against C. difficile RT001. Moreover, both extracts at concentration 50 µg/mL had no significant effect on cell viability compared to untreated cells. Pre-treatment of cells with extracts (50 µg/mL) significantly reduced the percentage of Vero cells rounding induced by Tox-S. Also, both pre-treatment and co-treatment of Tox-S stimulated Caco-2 cells with extracts significantly downregulated the gene expression level of IL-8, IL-1β, TNF-α, TGF-β, iNOS, Bax, caspase-9 and caspase-3 and upregulated the expression level of Bcl-2.

CONCLUSION

The results of the present study for the first time demonstrate the antimicrobial activity and protective effects of A. millefolium extracts on inflammatory response and apoptosis induced by Tox-S from C. difficile RT001 clinical strain in vitro. Further research is needed to evaluate the potential application of A. millefolium extracts as supplementary medicine for CDI prevention and treatment in clinical setting.

Toxic Megacolon: A Sequelae of Clostridioides difficile Infection in a Case of Necrotizing Fasciitis

Necrotizing fasciitis is an illness that ascends quickly and affects the fascia, subcutaneous tissues, and deeper skin layers. To combat this infection, strong antibiotics are used along with prompt debridement. Frequent usage of such drugs is connected to antibiotic-associated diarrhea and colonic illnesses like colitis. High-spectrum antibiotic usage over an extended period of time can alter the gut microbiota, which promotes the growth of commensal bacteria including Staphylococcus aureus and Clostridioides difficile (previously known as Clostridium difficile) resulting in complications such as toxic megacolon. C. difficile infection can result in extreme inflammation and colon dilatation leading to toxic megacolon. In order to effectively treat necrotizing fasciitis, a timely diagnosis and vigorous management are essential; failing of which may have fatal consequences such as sepsis and even mortality. We present a case of a 56-year-old male, suffering from necrotizing fasciitis of the left lower limb which further complicated to toxic megacolon and caused mortality of the patient. Timely presentation and early diagnosis can be helpful in better prognosis, which in the context of this case was delayed; had the patient presented to the hospital earlier, there were chances of preventing mortality.

Comparison of toxin gene expression levels and molecular typing of Clostridioides difficile strains isolated from patients with diarrhea

Aim

This study aimed to evaluate the expression of tcdA, tcdB, and binary toxin genes (cdtA and cdtB) by Real-Time PCR and molecular typing of Clostridioides difficile isolated from patient diarrhea samples from Hamadan Hospitals, west of Iran.

Background

The concentration of C. difficile toxins (CDTs) is associated with the severity of the disease and the mortality rate. Measuring CDT levels could provide a reliable and objective means of determining the severity of C. difficile infection (CDI).

Methods

From November 2018 to September 2019, 130 diarrhea samples were collected from hospitalized patients in three hospitals in Hamadan. C. difficle isolates were detected by culture and PCR. The presence of the genes encoding the toxin was identified by PCR, whereas the measurement of toxin expression was conducted using a relative Real-Time PCR technique. Genetic linkage of the isolates was also assessed by Ribotyping and Repetitive Extragenic Palindromic (rep-PCR) methods.

Results

Among 130 diarrhea samples, 16 (12.3%) were positive for C. difficile. Genes encoding cdtA and tcdB were detected in all isolates, and 8 (50%) and 6 (37.5%) isolates were positive for the cdtA and cdtB genes. Real-time PCR results showed different expression levels of the toxin genes. A significant increase in the expression of the tcdA gene was observed compared with the control strain (P<0.05). Besides, more expression of cdtA gene was observed in the strains compared with cdtB gene. Ribotyping and rep-PCR results showed high genetic diversity of C. difficile among hospitals investigated.

Conclusion

We encountered toxigenic C. difficile strains with various toxin expression levels, ribotypes, and rep types based on the findings of this study. This indicated that various clones from various sources circulate in the hospitals and among patients.

Clinical impact of diarrhea during enteral feeding after esophagectomy

BACKGROUND

Enteral feeding (EF) is recommended to enhance nutritional status after esophagectomy; however, diarrhea is a common complication of EF. We investigated the clinical and prognostic impact of diarrhea during EF after esophagectomy.

METHODS

One hundred and fifty-two patients who underwent transthoracic esophagectomy were enrolled. The King's stool chart was used for stool characterization. The short- and long-term outcomes were compared between a non-diarrhea (Group N) and diarrhea group (Group D).

RESULTS

A higher dysphagia score (≥ 1) was observed more frequently in Group D than in Group N (45.7% vs. 19.8%, p = 0.002). Deterioration of serum total protein, serum albumin, serum cholinesterase, and the prognostic nutritional index after esophagectomy was greater in Group D than in Group N (p = 0.003, 0.004, 0.014, and 0.001, respectively). Patients in Group D had significantly worse overall survival (OS) and recurrence-free survival (RFS) than those in Group N (median survival time (MST): OS, 21.9 vs. 30.6 months, p = 0.001; RFS, 12.4 vs. 27.7 months, p < 0.001). In stratified analysis due to age, although there was no difference in OS with or without diarrhea in young patients (MST: 24.1 months in a diarrhea group vs. 33.6 months in a non-diarrhea group, p = 0.218), patients in a diarrhea group had significantly worse OS than those in a non-diarrhea group in elderly patients (MST: 17.8 months vs. 27.9 months, p < 0.001).

CONCLUSIONS

Diarrhea during EF can put elderly patients at risk of postoperative malnutrition and a poor prognosis after esophagectomy.

Unraveling Physical Interactions of Clostridioides difficile with Phage and Phage-Derived Proteins Using In Vitro and Whole-Cell Assays

Physical interactions between bacteria and phages provide valuable insights into the mechanisms of phage infection and may provide information on the use of phages as a therapeutic approach. In this study, we employed a combination of in vitro and whole-cell assays to examine the interactions between Clostridioides difficile and phages and phage-derived proteins. These techniques can also be adapted for studying the physical interactions between other bacterial species and their associated phages.

Healthcare-associated Diarrhea due to Clostridioides difficile in Patients Attending a Tertiary Care Teaching Hospital of North India

Background

Healthcare-associated diarrhea (HCAD) is diarrhea that develops at least after 3 days of hospitalization, with the most common infectious cause being Clostridioides difficile. Over the last decade, there has been a remarkable growth in the frequency and severity of C. difficile infection (CDI), making it one of the most prevalent healthcare-associated infections. This study aimed to analyze the prevalence and risk factors associated with CDI.

Materials and methods

A total of 107 patients with clinical suspicion of having HCAD were included in this study. Enzyme-linked fluorescent assay (ELFA) technique-based glutamate dehydrogenase (GDH) and toxin A/B assay were used as per the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) for diagnosing CDI. The details about associated comorbidities were retrieved from the hospital information system records. The presence of risk factors was noted. Risk factors associated with CDI were looked for.

Results

Out of the 107 stool samples received in the microbiology laboratory from patients with suspected HCAD eight (7.6%) samples were positive for CDI. The most frequent comorbidity observed in these patients was renal illness (acute or chronic kidney disease). In this study, a total of 7/8 cases were on multiple antibiotics most common being carbapenem.

Conclusion

The 6-year prevalence of CDI observed in this study was found to be 7.6% risk factors, associated with CDI were kidney disease, diabetes mellitus, malignancy, and exposure to broad-spectrum antibiotics.

How to cite this article

Raj N, Agarwal J, Singh V, et al. Healthcare-associated Diarrhea due to Clostridioides difficile in Patients Attending a Tertiary Care Teaching Hospital of North India. Euroasian J Hepato-Gastroenterol 2024;14(1):60-64.

Effects of fibre-supplemented enteral feeds on bowel function of non-critically ill tube-fed adults: a meta-analysis of randomised controlled trials

Diarrhoea is common in enterally fed patients and can impact their nutritional and overall outcomes. This meta-analysis evaluates the potential benefits of fibre-supplemented (FS) feeds on incidence of diarrhoea and stool frequency in non-critically ill tube-fed adults. Databases including PubMed, Embase and CINAHL with full text were searched for randomised controlled trials (RCT) with adults on exclusive tube feeding, published until August 2022. The Cochrane Collaboration's tool was used for quality assessment. Studies with published results on incidence of diarrhoea and stool frequency were analysed using RevMan 5. Thirteen RCT with 847 non-critically ill patients between 20 and 90 years old without diarrhoea at the onset of enteral feeding were included. Study duration ranged from 3 to 35 d. Nine papers investigated the incidence of diarrhoea where intervention group was given FS and control was given non-fibre-supplemented (NFS) enteral feeds. Those receiving FS feeds were significantly less likely to experience diarrhoea as compared with those using NFS feeds (OR 0·44; 95 % CI 0·20, 0·95; P = 0·04; I2 = 71 %). Combined analysis showed no differences in stool frequency in those receiving NFS feeds (SMD 0·32; 95 % CI -0·53, 1·16; P = 0·47; I2 = 90 %). Results should be interpreted with caution due to considerable heterogeneity between study population, assessment tool for diarrhoea, potential conflict of interest and short duration of studies. This meta-analysis shows that FS feeds can reduce the incidence of diarrhoea in non-critically ill adults; however, the effects of stool frequency remain debatable.

Pharmacomicrobiomics and Drug-Infection Interactions: The Impact of Commensal, Symbiotic and Pathogenic Microorganisms on a Host Response to Drug Therapy

Microorganisms have a close relationship with humans, whether it is commensal, symbiotic, or pathogenic. Recently, it has been documented that microorganisms may influence the response to drug therapy. Pharmacomicrobiomics is an emerging field that focuses on the study of how variations in the microbiome affect the disposition, action, and toxicity of drugs. Two additional sciences have been added to complement pharmacomicrobiomics, namely toxicomicrobiomics, which explores how the microbiome influences drug metabolism and toxicity, and pharmacoecology, which refers to modifications in the microbiome as a result of drug administration. In this context, we introduce the concept of "drug-infection interaction" to describe the influence of pathogenic microorganisms on drug response. This review analyzes the current state of knowledge regarding the relevance of microorganisms in the host's response to drugs. It also highlights promising areas for future research and proposes the term "drug-infection interaction" as an extension of pharmacomicrobiomics.

Antibiotics and antibiotic-associated diarrhea: a real-world disproportionality study of the FDA adverse event reporting system from 2004 to 2022

BACKGROUND

Our study aimed to assess the risk signals of antibiotic-associated diarrhea (AAD) caused by various antibiotics using real-world data and provide references for safe clinical applications.

METHODS

We analyzed data extracted from the FDA Adverse Event Reporting System (FAERS) database, covering the period from the first quarter of 2004 to the third quarter of 2022. We computed the reporting odds ratio (ROR) for each antibiotic or antibiotic class to compare the signal difference. Furthermore, we also examined the differences in the onset times and outcomes of AAD caused by various antibiotics.

RESULTS

A total of 5,397 reports met the inclusion requirements. Almost all antibiotics, except tobramycin and minocycline (ROR 0.98; 95%CI: 0.64-1.51 and 0.42; 95%CI: 0.16-1.11, respectively), showed a significant correlation with AAD. The analysis of the correlation between different classes of antibiotics and AAD revealed that lincomycins (ROR 29.19; 95%CI: 27.06-31.50), third-generation cephalosporins (ROR 15.96; 95%CI: 14.58-17.47), and first/second generation cephalosporins (ROR 15.29; 95%CI: 13.74-17.01) ranked the top three. The ROR values for antibiotics from the same class of antibiotics also varied greatly, with the ROR values for third-generation cephalosporins ranging from 9.97 to 58.59. There were also differences in ROR values between β-lactamase inhibitors and their corresponding β-lactamase drugs, such as amoxicillin-clavulanate (ROR = 13.31; 95%CI: 12.09-14.65) and amoxicillin (ROR = 6.50; 95%CI: 5.69-7.44). 91.35% of antibiotics have an onset time of less than four weeks.

CONCLUSIONS

There is a significant correlation between almost all antibiotics and AAD, particularly lincomycins and β-lactam antibiotics, as well as a different correlation within the same class. These findings offer valuable evidence for selecting antibiotics appropriately.

Evaluating Healthcare-Associated Infections in Public Hospitals: A Cross-Sectional Study

BACKGROUND

Hospital-acquired infections (HAIs) pose a significant danger to global public health, mainly because their numbers are growing exponentially each year. Additionally, the rise of bacterial strains resistant to current treatment options further exacerbates this threat. This study aimed to examine the occurrences of HAIs identified in public hospitals at the county level.

METHODS

We conducted a cross-sectional study utilizing data provided to the Mures Public Health Directorate from all the public hospitals within the studied county. We examined HAIs reported during the period spanning from 2017 to 2021, which amounted to a total of 4603 cases.

RESULTS

The medical departments reported the highest prevalence of HAIs at 48.25%. The most common infections included enterocolitis with Clostridioides difficile (32.61%), COVID-19 (19.83%), bronchopneumonia (16.90%), sepsis, surgical wound infections, and urinary tract infections. The five most frequently identified pathogens were Clostridioides difficile (32.61%), SARS-CoV-2 (19.83%), Acinetobacter baumannii (11.82%), Klebsiella pneumoniae (9.58%), and Pseudomonas aeruginosa (7.95%). Acinetobacter baumannii was the predominant agent causing bronchopneumonia, while Klebsiella pneumoniae was the leading cause of sepsis cases. Escherichia coli was the primary agent behind the urinary tract infections, and Staphylococcus aureus MRSA was identified as the main etiology for wound infections and central catheter infections. Throughout the study period, there was a significant rise in Clostridioides difficile and Gram-negative bacteria prevalence rates.

CONCLUSIONS

This study identified increased Clostridioides difficile in HAI cases during COVID-19, highlighting the need for careful antibiotic use and emphasizing the growing challenge of multi-resistant strains in post-pandemic state hospitals.

Impact of the COVID-19 pandemic on Clostridioides difficile infection in a tertiary healthcare institution in Belgium

OBJECTIVES

Clostridioides difficile infection (CDI) causes the greatest number of healthcare-associated infectious diarrhoea. CDIs are transmitted by direct and indirect patient-to-patient contact and risk increases with the use of antibiotics. Since early 2020, the COVID-19 pandemic has affected healthcare systems in many ways including substantial changes in hygiene behaviour. The aim of this study was to assess whether CDI incidence differed during the COVID-19 pandemic compared to a year before.

METHODS

All tests for suspected CDI cases were recorded for a hospital in Brussels, Belgium. The percentage of CDI-positive results and incidences (total and healthcare-associated (HA)-CDI)) for years 2019, 2020, 2021, and 2022 were calculated. Antibiotic consumption was analysed for years 2019 and 2020.

RESULTS

Since the COVID-19 pandemic struck, a significant reduction of up to 39% was observed in the number of Clostridioides difficile stool tests in our hospital. A significant decrease in the percentage of positive tests and a 50% decrease in the incidence of CDI (total and HA-CDI) was found for 2020 compared with 2019 and confirmed for years 2021 and 2022. The decrease in CDI incidence was mostly marked in haematology, nephrology, and gastroenterology units. No significant change in the use of antibiotics was found.

CONCLUSION

The global decrease in CDI incidence observed in our hospital was not associated with a change in the use of antibiotics. The control measures implemented to prevent COVID-19 transmission may explain a reduction in CDI incidence. An underdiagnosis of CDI cannot be excluded.

Clostridioides difficile Infection: A Clinical Review of Pathogenesis, Clinical Considerations, and Treatment Strategies

BACKGROUND

Clostridioides difficile infection (CDI) is a common nosocomial infection. Risk factors for developing CDI include prior hospitalization, being older than 65 years old, antibiotic use, and chronic disease. It is linked with diarrhea and colitis and can vary in severity. It is a major cause of increased morbidity and mortality among hospitalized patients. However, community-acquired CDI is also increasing. Proper diagnosis and determination of severity are crucial for the treatment of CDI. Depending on how severe the CDI is, the patient may endorse different symptoms and physical exam findings. The severity of CDI will determine how aggressively it is treated. Management and treatment: Laboratory studies can be helpful in the diagnosis of CDI. In this regard, common labs include complete blood count, stool assays, and, in certain cases, radiography and endoscopy. Mild-to-moderate colitis is treated with antibiotics, but severe colitis requires a different approach, which may include surgery. Several alternative therapies for CDI exist and have shown promising results. This review will touch upon these therapies, which include fecal transplants, intravenous immunoglobulin, and the use of cholestyramine and tigecycline.

CONCLUSION

Prevention of CDI can be achieved by proper hygiene, vaccinations, and detecting the infection early. Proper hygiene is indeed noted to be one of the best ways to prevent CDI in the hospital setting. Overprescribing antibiotics is also another huge reason why CDI occurs. Proper prescription of antibiotics can also help reduce the chances of acquiring CDI.

A Pharmacovigilance Study Regarding the Risk of Antibiotic-Associated Clostridioides difficile Infection Based on Reports from the EudraVigilance Database: Analysis of Some of the Most Used Antibiotics in Intensive Care Units

The Gram-positive anaerobic bacterium Clostridioides difficile (CD) can produce intense exotoxins, contributing to nosocomial infections, and it is the most common cause of health-care-associated infectious diarrhea. Based on spontaneous Individual Case Safety Reports from EudraVigilance (EV), we conducted a descriptive analysis of Clostridioides difficile infection (CDI) cases that reported a spontaneous adverse reaction related to using ceftriaxone, colistimethate, ciprofloxacin, gentamicin, linezolid, meropenem, and piperacillin/tazobactam. Most ADR reports registered in EV that were related to CDI were associated with ceftriaxone (33%), ciprofloxacin (28%), and piperacillin/tazobactam (21%). Additionally, the disproportionality analysis performed showed that all studied antibiotics had a lower reporting probability when compared to clindamycin. A causal relationship between a drug and the occurrence of an adverse reaction cannot be established from EV data alone because the phenomena of underreporting, overreporting, and reporting bias may affect the results. Based on the analysis of the collected data, this study underlines the importance of surveillance and monitoring programs for the consumption of antibiotics. Furthermore, it is essential to use standardized laboratory tests to define CDI's nature accurately. To prevent this infection, specialists should collaborate and adhere strictly to antibiotic stewardship programs, hygiene practices, and isolation protocols.

Effects of Lactobacillus plantarum and Weissella viridescens on the Gut Microbiota and Serum Metabolites of Mice with Antibiotic-Associated Diarrhea

Antibiotic-associated diarrhea (AAD) refers to diarrhea caused by gut microbiota disorders after the use of antibiotics, which seriously threatens the health of humans and animals. Therefore, it is necessary to find an effective therapy to treat AAD. This research aimed to explore the effects of Lactobacillus plantarum H-6 (L. plantarum H-6) and Weissella viridescens J-1 (W. viridescens J-1) on alleviating antibiotic-associated diarrhea induced by lincomycin hydrochloride (LH) in mice. The results show that L. plantarum H-6 could significantly reduce the expression of pro-inflammatory factors such as IL-1β and IL-6 in colon tissue. At the same time, L. plantarum H-6 significantly increased the abundance of Lactobacillus and Akkermansia, decreased the abundance of Bacteroides, and increased the contents of L-tryptophan, LysoPC (20:4 (8Z, 11Z, 14Z, 17Z)), reduced riboflavin, threoninyl-methionine, and N-palmitoyl in serum. However, W. viridescens J-1 had little effect on the treatment of AAD. It can be concluded that L. plantarum H-6 can regulate mice's colonic microbial composition, improve their serum metabolic process, and alleviate antibiotic-associated diarrhea. This research may provide a novel therapeutic option for AAD.

Empiric Anti-Pseudomonal β-Lactam Monotherapy Versus Fluoroquinolone Combination Therapy in Patients With Hospital-Acquired Pneumonia: A Multicenter Cohort Study With Propensity Score Matching

BACKGROUND

There is insufficient data on the benefits of empiric antibiotic combinations for hospital-acquired pneumonia (HAP). We aimed to investigate whether empiric anti-pseudomonal combination therapy with fluoroquinolones decreases mortality in patients with HAP.

METHODS

This multicenter, retrospective cohort study included adult patients admitted to 16 tertiary and general hospitals in Korea between January 1 and December 31, 2019. Patients with risk factors for combination therapy were divided into anti-pseudomonal non-carbapenem β-lactam monotherapy and fluoroquinolone combination therapy groups. Primary outcome was 30-day mortality. Propensity score matching (PSM) was used to reduce selection bias.

RESULTS

In total, 631 patients with HAP were enrolled. Monotherapy was prescribed in 54.7% (n = 345) of the patients, and combination therapy was prescribed in 45.3% (n = 286). There was no significant difference in 30-day mortality between the two groups (16.8% vs. 18.2%, P = 0.729) or even after the PSM (17.5% vs. 18.2%, P = 0.913). After the PSM, adjusted hazard ratio for 30-day mortality from the combination therapy was 1.646 (95% confidence interval, 0.782-3.461; P = 0.189) in the Cox proportional hazards model. Moreover, there was no significant difference in the appropriateness of initial empiric antibiotics between the two groups (55.0% vs. 56.8%, P = 0.898). The proportion of multidrug-resistant (MDR) pathogens was high in both groups.

CONCLUSION

Empiric anti-pseudomonal fluoroquinolone combination therapy showed no survival benefit compared to β-lactam monotherapy in patients with HAP. Caution is needed regarding the routine combination of fluoroquinolones in the empiric treatment of HAP patients with a high risk of MDR.

Antibiotic Prophylaxis in Surgery: Current Insights and Future Directions for Surgical Site Infection Prevention

Surgical site infections (SSIs) remain a significant concern in the field of surgery, contributing to patient morbidity, prolonged hospital stays, and increased healthcare costs. Antibiotic prophylaxis, the administration of antibiotics before surgery, has been a cornerstone in preventing SSIs for decades. This review explores the current state of antibiotic prophylaxis in surgery, offering insights into its effectiveness, challenges, and emerging trends. In this comprehensive analysis, we delve into the historical development of antibiotic prophylaxis, examining its evolution from early practices to modern guidelines. We explore the various classes of antibiotics commonly used, their dosing regimens, and the importance of timing in optimizing prophylactic interventions. Additionally, we investigate the role of patient-specific factors, such as comorbidities and allergies, in tailoring antibiotic prophylaxis to individual needs. While antibiotic prophylaxis has undeniably reduced the incidence of SSIs, concerns about antimicrobial resistance and adverse effects necessitate a reevaluation of current practices. This review presents a critical assessment of the challenges posed by the overuse and misuse of antibiotics in surgery and highlights the urgent need for judicious antibiotic stewardship. Moreover, the future of antibiotic prophylaxis holds promise with the emergence of innovative strategies such as antimicrobial coatings, probiotics, and immunomodulatory agents. We discuss these novel approaches and their potential to enhance SSI prevention while minimizing antibiotic-related risks. In conclusion, antibiotic prophylaxis in surgery has been instrumental in reducing SSIs, but its continued effectiveness requires a multifaceted approach. By addressing current challenges, promoting antibiotic stewardship, and embracing innovative strategies, we can advance the field of SSI prevention and improve patient outcomes in the years to come. This review provides valuable insights and direction for clinicians, researchers, and policymakers as they navigate the evolving landscape of surgical prophylaxis.

Efficacy of Intravenous Colistin Monotherapy Versus Colistin Combined With Meropenem in Patients With Multidrug-Resistant Infections: A Retrospective Observational Study

Background Intensive care units frequently contend with infections caused by highly drug-resistant organisms, particularly Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Enterobacterales (CRE), which often lead to high mortality rates. Colistin (colomycin) is employed to treat infections, notably extremely drug-resistant (XDR) bacteria. Antibiotic combination treatment is a frequently used tactic in this endeavour. However, the widespread use of antibiotics in synergy could result in the emergence of resistance and a rise in side effects, such as those linked to Clostridium difficile infection. The aim of the study was to assess and contrast the clinical results of intravenous colistin monotherapy with the combination of colistin and meropenem in patients experiencing MDR bacteremia resulting from Acinetobacter Baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Enterobacterales (CRE). Methods In this retrospective observational study, an analysis spanning two years, from June 2021 to June 2023, was conducted at a teaching hospital located in Karachi, Pakistan. The research involved the retrospective examination of medical records from 132 patients who had been diagnosed with MDR bacteremia. Patients were divided into two categories based on their treatment regimen, either intravenous colistin monotherapy or intravenous colistin combined with meropenem. Among the 132 patients included in the analysis, 66 underwent colistin monotherapy, while the other 66 received a combination of colistin and meropenem. The primary focus of evaluation in this study centered on the 14-day all-cause mortality, while secondary outcomes encompassed clinical success and microbiologic cure. Results The mean age of patients in both groups was comparable, and there were no noteworthy gender differences. Additionally, the distribution of infection types and the isolated pathogens showed no substantial distinctions between the two groups. The study revealed no statistically significant disparities in 14-day mortality, improvement in Sequential Organ Failure Assessment (SOFA) score, or the proportion of patients who were cured and survived between the two treatment groups. Conclusion The findings from this study lead to the conclusion that there exists no significant disparity in the efficacy of colistin monotherapy compared to the combination of colistin with meropenem in the treatment of MDR bacteremia stemming from Acinetobacter Baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Enterobacterales (CRE). The results provide a basis for future research and underscore the significance of ongoing endeavors to refine antibiotic treatment strategies in response to the worldwide issue of antibiotic resistance.

Controlling Intestinal Infections and Digestive Disorders Using Probiotics

After consumption, probiotics provide health benefits to the host. Probiotics and their metabolites have therapeutic and nutritional properties that help to alleviate gastrointestinal, neurological, and cardiovascular problems. Probiotics strengthen host immunity through various mechanisms, including improved gut barrier function, receptor site blocking, competitive exclusion of pathogens, and the production of bioactive molecules. Emerging evidence suggests that intestinal bowel diseases can be fatal, but regular probiotic consumption can alleviate disease symptoms. The use and detailed description of the health benefits of probiotics to consumers in terms of reducing intestinal infection, inflammation, and digestive disorders are discussed in this review. The well-designed and controlled studies that examined the use of probiotics to reduce life-threatening activities caused by intestinal bowel diseases are also covered. This review discussed the active principles and potency of probiotics as evidenced by the known effects on host health, in addition to providing information on the mechanism of action.

Development and characterization of phage display-derived anti-toxin antibodies neutralizing TcdA and TcdB of Clostridioides difficile

TcdA and TcdB are known as the major virulence attributes of Clostridioides difficile. Hence, neutralizing the TcdA and TcdB activities can be considered as an efficient therapeutic approach against C. difficile infection (CDI). In this work, we utilized phage display technique to select single-chain fragment variable (scFv) fragments as recombinant antibodies displayed on the surface of phages, which specifically target native TcdA, or TcdB (nTcdA and nTcdB), and their recombinant C-terminal combined repetitive oligopeptide (CROP) domains (rTcdA and rTcdB). After three rounds of biopanning, abundance of phage clones displaying high reactivity with TcdA or TcdB was quantified through enzyme-linked immunosorbent assay (ELISA). Furthermore, selected scFvs were characterized by cell viability and neutralization assays. The gene expression of immunological markers, IL-8 and TNF-α, was examined in treated Caco-2 cells by RT-qPCR. The epitopes of neutralizing scFvs were also identified by molecular docking. Totally, 18 scFv antibodies (seven for TcdA and 11 for TcdB) were identified by ELISA. Among selected scFvs, two clones for TcdA (rA-C2, A-C9) and three clones for TcdB (rB-B4, B-F5, B-F11) exhibited the highest neutralizing activity in Caco-2 and Vero cells. Moreover, the cocktail of anti-TcdA and anti-TcdB antibodies notably decreased the mRNA expression of TNF-α and IL-8 in Caco-2 cells. Molecular docking revealed that the interaction between scFv and toxin was mostly restricted to CROP domain of TcdA or TcdB. Our results collectively provided more insights for the development of neutralizing scFvs against C. difficile toxins using phage display. Further research is needed to meticulously evaluate the potential of scFvs as an alternative treatment for CDI using animal models and clinical trials.IMPORTANCETargeting the major toxins of Clostridioides difficile by neutralizing antibodies is a novel therapeutic approach for CDI. Here, we report a panel of new anti-TcdA (rA-C2, A-C9) and anti-TcdB (rB-B4, B-F5, and B-F11) recombinant antibody fragments (scFvs) isolated from Tomlinson I and J libraries using phage display technique. These scFv antibodies were capable of neutralizing their respective toxin and showed promise as potential therapeutics against TcdA and TcdB of C. difficile in different in vitro models. In addition, in silico analysis showed that at least two neutralization mechanisms, including inhibiting cell surface binding of toxins and inhibiting toxin internalization can be proposed for the isolated scFvs in this work. These findings provide more insights for the applicability of specific scFvs toward C. difficile toxins at in vitro level. However, further research is required to evaluate the potential application of these scFvs as therapeutic agents for CDI treatment in clinical setting.

Outer membrane translocation of pyocins via the copper regulated TonB-dependent transporter CrtA

Pseudomonas aeruginosa is a common cause of serious hospital-acquired infections, the leading proven cause of mortality in people with cystic fibrosis and is associated with high levels of antimicrobial resistance. Pyocins are narrow-spectrum protein antibiotics produced by P. aeruginosa that kill strains of the same species and have the potential to be developed as therapeutics targeting multi-drug resistant isolates. We have identified two novel pyocins designated SX1 and SX2. Pyocin SX1 is a metal-dependent DNase while pyocin SX2 kills cells through inhibition of protein synthesis. Mapping the uptake pathways of SX1 and SX2 shows these pyocins utilize a combination of the common polysaccharide antigen (CPA) and a previously uncharacterized TonB-dependent transporter (TBDT) PA0434 to traverse the outer membrane. In addition, TonB1 and FtsH are required by both pyocins to energize their transport into cells and catalyze their translocation across the inner membrane, respectively. Expression of PA0434 was found to be specifically regulated by copper availability and we have designated PA0434 as Copper Responsive Transporter A, or CrtA. To our knowledge these are the first S-type pyocins described that utilize a TBDT that is not involved in iron uptake.

Clostridioides difficile resistance to antibiotics, including post-COVID-19 data

INTRODUCTION

Updating data on Clostridioides difficile antibiotic resistance is important for treatment improvement of C. difficile infections (CDIs).

AREAS COVERED

Results from 20 countries were included. The mean resistance to 2 mg/l vancomycin, 2 mg/l metronidazole, 4 mg/l moxifloxacin, and 4 mg/l clindamycin was 4.7% (0 to ≥ 26% in two studies), 2.6% (0 to ≥ 40% in 3 studies), 34.9% (6.6->80%), and 61.0% (30->90%), respectively. Resistance to erythromycin (>60-88%), rifampin (>23-55.0%), imipenem (0.6 to > 78% in a clone), tigecycline (0-<5.0%), and fidaxomicin (0-2%) was also found. Resistance to ≥ 5 antibiotics of different classes was reported in some countries. High resistance and multidrug resistance were observed in hypervirulent and epidemic strains. Although only 1% of COVID-19 patients had CDIs, the proportion might be underestimated.

EXPERT OPINION

C. difficile antimicrobial susceptibility varied by country/region, study period, and circulating ribotypes. For CDI treatment, fidaxomicin (preferably) or vancomycin is recommended, while metronidazole is suitable for mild infections. New approaches, including biotherapeutics (Rebyota), strains, antibiotics (ridinilazole and ibezapolstat), and monoclonal antibodies/cocktails merit further evaluation. Because of the resistance rate variations, C. difficile antibiotic susceptibility should be regularly monitored. Post-COVID-19 resistance should be separately presented. Some discrepancies between vancomycin and metronidazole results need to be clarified.

Probiotics: insights and new opportunities for Clostridioides difficile intervention

Clostridioides difficile infection (CDI) is a life-threatening disease caused by the Gram-positive, opportunistic intestinal pathogen C. difficile. Despite the availability of antimicrobial drugs to treat CDI, such as vancomycin, metronidazole, and fidaxomicin, recurrence of infection remains a significant clinical challenge. The use of live commensal microorganisms, or probiotics, is one of the most investigated non-antibiotic therapeutic options to balance gastrointestinal (GI) microbiota and subsequently tackle dysbiosis. In this review, we will discuss major commensal probiotic strains that have the potential to prevent and/or treat CDI and its recurrence, reassess the efficacy of probiotics supplementation as a CDI intervention, delve into lessons learned from probiotic modulation of the immune system, explore avenues like genome-scale metabolic network reconstructions, genome sequencing, and multi-omics to identify novel strains and understand their functionality, and discuss the current regulatory framework, challenges, and future directions.

Targeting the human gut microbiome with small-molecule inhibitors

The human gut microbiome is a complex microbial community that is strongly linked to both host health and disease. However, the detailed molecular mechanisms underlying the effects of these microorganisms on host biology remain largely uncharacterized. The development of non-lethal, small-molecule inhibitors that target specific gut microbial activities enables a powerful but underutilized approach to studying the gut microbiome and a promising therapeutic strategy. In this Review, we will discuss the challenges of studying this microbial community, the historic use of small-molecule inhibitors in microbial ecology, and recent applications of this strategy. We also discuss the evidence suggesting that host-targeted drugs can affect the growth and metabolism of gut microbes. Finally, we address the issues of developing and implementing microbiome-targeted small-molecule inhibitors and define important future directions for this research.

The natural product chlorotonil A preserves colonization resistance and prevents relapsing Clostridioides difficile infection

Clostridioides difficile infections (CDIs) remain a healthcare problem due to high rates of relapsing/recurrent CDIs (rCDIs). Breakdown of colonization resistance promoted by broad-spectrum antibiotics and the persistence of spores contribute to rCDI. Here, we demonstrate antimicrobial activity of the natural product class of chlorotonils against C. difficile. In contrast to vancomycin, chlorotonil A (ChA) efficiently inhibits disease and prevents rCDI in mice. Notably, ChA affects the murine and porcine microbiota to a lesser extent than vancomycin, largely preserving microbiota composition and minimally impacting the intestinal metabolome. Correspondingly, ChA treatment does not break colonization resistance against C. difficile and is linked to faster recovery of the microbiota after CDI. Additionally, ChA accumulates in the spore and inhibits outgrowth of C. difficile spores, thus potentially contributing to lower rates of rCDI. We conclude that chlorotonils have unique antimicrobial properties targeting critical steps in the infection cycle of C. difficile.

Clostridioides difficile, a New “Superbug”

Clostridioides difficile is a Gram-positive, spore-forming, anaerobic bacterium. The clinical features of C. difficile infections (CDIs) can vary, ranging from the asymptomatic carriage and mild self-limiting diarrhoea to severe and sometimes fatal pseudomembranous colitis. C. difficile infections (CDIs) are associated with disruption of the gut microbiota caused by antimicrobial agents. The infections are predominantly hospital-acquired, but in the last decades, the CDI patterns have changed. Their prevalence increased, and the proportion of community-acquired CDIs has also increased. This can be associated with the appearance of hypervirulent epidemic isolates of ribotype 027. The COVID-19 pandemic and the associated antibiotic overuse could additionally change the patterns of infections. Treatment of CDIs is a challenge, with only three appropriate antibiotics for use. The wide distribution of C. difficile spores in hospital environments, chronic persistence in some individuals, especially children, and the recent detection of C. difficile in domestic pets can furthermore worsen the situation. “Superbugs” are microorganisms that are both highly virulent and resistant to antibiotics. The aim of this review article is to characterise C. difficile as a new member of the “superbug” family. Due to its worldwide spread, the lack of many treatment options and the high rates of both recurrence and mortality, C. difficile has emerged as a major concern for the healthcare system.

Nurses’ Knowledge, Attitudes and Practices on the Management of Clostridioides difficile Infection: A Cross-Sectional Study

Clostridioides difficile is, worldwide, the leading cause of hospital-acquired infection. Outbreaks are largely related to antibiotic exposure and contact contamination, but little is known about C. difficle infection (CDI) awareness in the nurse population. We conducted a cross-sectional survey to study Italian nurses, based on CDI guidelines. We recruited 200 nurses working in 14 Italian hospitals. Using a one-way analysis of variance of knowledge scores, female nurses (mean 9.67 (standard deviation ± 1.63), p = 0.03), and nurses with a higher level of university education (mean 9.79 (SD ± 1.67), p = 0.04) were demonstrated to have better knowledge about CDI. In addition, 92.5% (n = 184) of the sample declared that they did not have specific postgraduate training about CDI. Seventy-four percent (n = 149) of the respondents declared that they used procedures, protocols and guidelines about CDI in their workplace, but only 46.5% (n = 93) reported using C. difficile-specific bundles during their daily practice. In conclusion, our study highlights a lack of knowledge concerning CDI clinical guidelines among Italian nurses.

Plant-derived nanoparticles as alternative therapy against Diarrheal pathogens in the era of antimicrobial resistance: A review

Diarrhea is a condition in which feces is discharged from the bowels frequently and in a liquid form. It is one of the frequent causes of morbidity and mortality in developing countries. The impact of Diarrhea is worsened by the increasing incidence of antimicrobial resistance among the causative agents, and this is now categorized as a global healthcare challenge. Antimicrobial resistance among Diarrheal pathogens also contributes to extended infection durations, and huge economic loss even in countries with advanced public health policies. The ever-increasing incidence of antimicrobial resistance including the contraindications arising from the administration of antibiotics in some Diarrheal cases highlights a crucial need for the development of novel non-antibiotic alternative agents for therapeutic and biocontrol applications. One such intervention includes the application of plant-derived nanoparticles (PDNPs) with novel antimicrobial properties. Given their small size and large surface area to volume ratio, PDNPs can attack target bacterial cell walls to generate reactive oxygen species that may simultaneously disrupt bacteria cell components such as DNA and proteins leading to cell damage or death. This potential can make it very difficult for pathogenic organisms to develop resistance against these antibacterial agents. In this review, we provide a critical overview on the antimicrobial resistance crisis among Diarrheagenic bacteria. We also discuss the evidence from the existing literature to support the potential associated with the use of PDNPs as alternative therapeutic agents for multidrug resistant and antibiotics administer contraindicated bacteria that are associated with Diarrhea.

Correlation between hospital-onset and community-onset Clostridioides difficile infection incidence: Ward-level analysis following hospital relocation

BACKGROUND

The development of hospital-onset Clostridioides difficile infection (HO-CDI) is affected by patient and environmental risk factors. We investigated changes in the incidence of HO-CDI after relocation to a newly built hospital with 50% private rooms and evaluated the associated factors.

METHODS

A retrospective study was conducted to assess trends in CDI incidences before and after the relocation using segmented regression analysis model. The association between CDI incidence and environmental factors at the ward-level was assessed using a linear regression analyses model.

RESULTS

The HO-CDI incidence decreased from 6.14 to 1.17 per 10,000 patient-days in the old and new hospital, respectively. Similarly, the community-onset CDI (CO-CDI) incidence decreased from 1.71 to 0.46 per 1000 admissions. HO-CDI incidence was positively correlated with CO-CDI incidence and inversely correlated with the private room ratio (adjusted R2 = 0.83). Almost half of the CO-CDI patients had been hospitalized within 28 days preceding the onset.

DISCUSSION

Environmental improvements after relocation may have reduced the reservoir of C. difficile, resulting in a decrease in the number of asymptomatic carriers and CO-CDI patients.

CONCLUSION

Relocation to a new hospital significantly reduced HO-CDI incidence, concomitantly decreasing the incidence of CO-CDI, potentially due to environmental improvements.

Off-Label Use of Dalbavancin for Sequential Treatment of Spondylodiscitis by Methicillin-Resistant Staphylococcus aureus: A Retrospective Single-Centre Experience

Background: Our aim was to describe the clinical outcome and safety of the sequential treatment with off-label dalbavancin in patients with spondylodiscitis that is caused by methicillin-resistant Staphylococcus aureus (MRSA). Methods: We retrospectively included all patients >18 years of age with spondylodiscitis that is caused by MRSA that was treated with dalbavancin from January 2018−January 2021, recording the instances of clinical cure/failure, adverse events, and the need to be re-hospitalized after the initiation of dalbavancin. In 2/15 patients, we performed therapeutic drug monitoring (TDM) for dalbavancin. Results: We included 15 patients, 53.3% of them were females, with a median age of 67.9 years (57.4−78.5); 100% patients reported back pain, while a fever was present only in 2/15 cases. The spondylodiscitis was localized in 86.6% cases at the lumbar level. A median of a 2-week in-hospital intravenous vancomycin was followed by dalbavancin with a median duration of 12 weeks (12−16). All patients reported a clinical cure, except for a woman who is still on a suppressive treatment. No patient needed to be re-hospitalized, access to emergency department, or experienced adverse events. The TDM for dalbavancin showed that more than 90% of the determinations were above the pharmacodynamic target against staphylococci. Conclusions: The results from our unique, even if it was small, cohort demonstrated that dalbavancin can be a safe/effective option as a sequential treatment in patients with serious infections requiring prolonged antibiotic therapy, such as spondylodiscitis.

Dietary-protein sources modulate host susceptibility to Clostridioides difficile infection through the gut microbiota

Clostridioides difficile causes nosocomial antibiotic-associated diarrhea on a global scale. Susceptibility to C. difficile infection (CDI) is influenced by the composition and metabolism of gut microbiota, which in turn are affected by diet. However, the mechanism underlying the interplay between diet and gut microbiota that modulates susceptibility to CDI remains unclear. Here, we show that a soy protein diet increases the mortality of antibiotic-treated, C. difficile-infected mice while also enhancing the intestinal levels of amino acids (aas) and relative abundance of Lactobacillus genus. Indeed, Ligilactobacillus murinus-mediated fermentation of soy protein results in the generation of aas, thereby promoting C. difficile growth, and the process involves the anchored cell wall proteinase PrtP. Thus, mutual interaction between dietary protein and the gut microbiota is a critical factor affecting host susceptibility to CDI, suggesting that dietary protein sources can be an important determinant in controlling the disease.

Clostridium perfringens Spores in Urology Hospitals

Background: Clostridium spp. spores are resistant to many factors, including alcohol-based disinfectants. The presence of clostridial spores in a hospital environment may lead to infection outbreaks among patients and health care workers. Objective: This study aimed to detect clostridial spores in aurology hospital using C diff Banana Broth™ and assess the antibiotic sensitivity and toxinotypes of isolates. Methods: After diagnosing COVID-19 in medical staff and closing an 86-bed urology hospital in 2020 for H2O2 fogging, 58 swabs from the hospital environment were inoculated to C diff Banana Broth™, incubated at 37°C for 14 days, checked daily, and positive broths were sub-cultured anaerobically for 48 h at 37°C. After identification, multiplex PCR (mPCR) was performed for Clostridium perfringens, C. difficile toxin genes, and MIC determination. Results: In this study, 16.58 (~ 28%) strains of Clostridium spp. were cultured: 11 - C. perfringens, 2 - C. baratii, and 1 each of C. paraputrificum, C. difficile, and C. clostridioforme. Moreover, C. difficile produced all toxins, and 11 C. perfringens consisted of 1 cpa, 7 cpb2, 2 cpiA, and 1 cpb gene-positive. All isolates were sensitive to metronidazole, vancomycin, moxifloxacin, penicillin/tazobactam, and rifampicin. Two out of the 11 C. perfringens strains were resistant to erythromycin and clindamycin. Conclusions: Regardless of the performed H2O2 fogging, antibiotic-resistant, toxigenic strains of C. perfringens (69%) obtained from the urology hospital environment were cultured using C diff Banana Broth™, indicating the need to develop the necessary sanitary and epidemiological procedures in this hospital.

Clostridioides difficile Infection in Liver Cirrhosis: A Concise Review

Clostridium difficile is a Gram-positive bacillus with fecal-oral transmission and is currently one of the most common nosocomial infections worldwide, which was renamed Clostridioides difficile in 2016. Clostridioides difficile infection (CDI) is a prevalent infection in cirrhosis and negatively affects prognosis. This study aimed to provide a concise review with clinical practice implications. The prevalence of CDI in cirrhotic patients increases, while the associated mortality decreases. Multiple groups of risk factors increase the likelihood of CDI in patients with cirrhosis, such as antibiotic use, the severity of cirrhosis, some comorbidities, and demographic aspects. Treatment in the general population is currently described in the latest guidelines. In patients with cirrhosis, rifaximin and lactulose have been shown to reduce CDI risk due to their modulatory effects on the intestinal flora, although conflicting results exist. Fecal microbiota transplantation (FMT) as a treatment for the second or subsequent CDI recurrences has demonstrated a good safety and efficacy in cirrhosis and CDI. Future validation in more prospective studies is needed. Screening of asymptomatic patients appears to be discouraged for the prevention currently, with strict hand hygiene and cleaning of the ward and medical equipment surfaces being the cornerstone of minimizing transmission.

Clostridioides difficile co-infection in patients with COVID-19

Aim: To assess the impact of Clostridioides difficile infection on the course of COVID-19. Methods: The authors included 809 patients with COVID-19 in this retrospective study: 55 had C. difficile infection, 23 had C. difficile-negative antibiotic-associated diarrhea and 731 had no diarrhea. C. difficile in feces was determined by immunochromatographic test for its toxins. Results:C. difficile infection was associated with increased risk of death (hazard ratio = 2.6; p = 0.021), especially after 20 days of disease (hazard ratio = 6.5; p < 0.001). C. difficile infection-associated diarrhea was longer and more severe than C. difficile-negative antibiotic-associated diarrhea. Unlike patients with C. difficile-negative antibiotic-associated diarrhea, patients with C. difficile infection were admitted to the intensive care unit and needed mechanical ventilation more often than those without diarrhea. Conclusion:C. difficile infection worsens the course and prognosis of COVID-19.

EpiBuilder: A Tool for Assembling, Searching, and Classifying B-Cell Epitopes

Epitopes are portions of a protein that are recognized by antibodies. These small amino acid sequences represent a significant breakthrough in a branch of bioinformatics called immunoinformatics. Various software are available for linear B-cell epitope (BCE) prediction such as ABCPred, SVMTrip, EpiDope, and EpitopeVec; a well-known BCE predictor is BepiPred-2.0. However, despite the prediction, there are several essential steps, such as epitope assembly, evaluation, and searching for epitopes in other proteomes. Here, we present EpiBuilder (https://epibuilder.sourceforge.io), a user friendly software that assists in epitope assembly, classifying and searching using input results of BepiPred-2.0. EpiBuilder generates several output results from these data and supports a proteome-wide processing approach. In addition, this software provides the following features: Chou & Fasman beta-turn prediction, Emini surface accessibility prediction, Karplus and Schulz flexibility prediction, Kolaskar and Tongaonkar antigenicity, Parker hydrophilicity prediction, N-glycosylation domains, and hydropathy. These information generate a unique topology for each epitope, visually demonstrating its characteristics. The software can search the entire epitope sequence in various FASTA files, and it allows to use BLASTP to identify epitopes that eventually have sequence variations. As an EpiBuilder application, we developed a epitope dataset from the protozoan Trypanosoma brucei gambiense, the gram-positive bacterium Clostridioides difficile, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Risk Factors for Hospital Readmission for Clostridioides difficile Infection: A Statewide Retrospective Cohort Study

(1) Background: Clostridioides difficile infection (CDI) is associated with a high recurrence rate, and a significant proportion of patients with CDI are readmitted following discharge. We aimed to identify the risk factors for CDI-related readmission within 90 days following an index hospital stay for CDI. (2) Methods: We analyzed the electronic medical data of admitted patients in our health system over a two-year period. A multivariate logistic regression model, supplemented with bias-corrected and accelerated confidence intervals (BCa-CI), was implemented to assess the risk factors. (3) Results: A total of 1253 adult CDI index cases were included in the analysis. The readmission rate for CDI within 90 days of discharge was 11% (140/1253). The risk factors for CDI-related readmission were fluoroquinolone exposure within 90 days before the day of index CDI diagnosis (aOR: 1.58, 95% CI: 1.05–2.37), higher Elixhauser comorbidity score (aOR: 1.05, 95% CI: 1.02–1.07), and being discharged home (aOR: 1.64, 95% CI: 1.06–2.54). In contrast, a longer length of index stay (aOR: 0.97, 95% BCa-CI: 0.95–0.99) was associated with reduced odds of readmission for CDI. (4) Conclusion: More than 1 out of 10 patients were readmitted for CDI following an index hospital stay for CDI. Patients with recent previous fluoroquinolone exposure, greater overall comorbidity burden, and those discharged home are at higher risk of readmission for CDI.