Clostridium Difficile Infection in Patients with HIV/AIDS

Mining Autoimmune-Disorder-Linked Molecular-Mimicry Candidates in Clostridioides difficile and Prospects of Mimic-Based Vaccine Design: An In Silico Approach

Molecular mimicry, a phenomenon in which microbial or environmental antigens resemble host antigens, has been proposed as a potential trigger for autoimmune responses. In this study, we employed a bioinformatics approach to investigate the role of molecular mimicry in Clostridioides difficile-caused infections and the induction of autoimmune disorders due to this phenomenon. Comparing proteomes of host and pathogen, we identified 23 proteins that exhibited significant sequence homology and were linked to autoimmune disorders. The disorders included rheumatoid arthritis, psoriasis, Alzheimer's disease, etc., while infections included viral and bacterial infections like HIV, HCV, and tuberculosis. The structure of the homologous proteins was superposed, and RMSD was calculated to find the maximum deviation, while accounting for rigid and flexible regions. Two sequence mimics (antigenic, non-allergenic, and immunogenic) of ≥10 amino acids from these proteins were used to design a vaccine construct to explore the possibility of eliciting an immune response. Docking analysis of the top vaccine construct C2 showed favorable interactions with HLA and TLR-4 receptor, indicating potential efficacy. The B-cell and T-helper cell activity was also simulated, showing promising results for effective immunization against C. difficile infections. This study highlights the potential of C. difficile to trigger autoimmunity through molecular mimicry and vaccine design based on sequence mimics that trigger a defensive response.

Epidemiology and aetiology of moderate to severe diarrhoea in hospitalised patients ≥5 years old living with HIV in South Africa, 2018-2021: A case-control analysis

Diarrhoea is a recognised complication of HIV-infection, yet there are limited local aetiological data in this high-risk group. These data are important for informing public health interventions and updating diagnostic and treatment guidelines. This study aimed to determine the pathogenic causes of diarrhoeal admissions in people living with HIV (PLHIV) compared to hospital controls between July 2018 and November 2021. Admitted diarrhoeal cases (n = 243) and non-diarrhoeal hospital controls (n = 101) ≥5 years of age were enrolled at Kalafong, Mapulaneng and Matikwana hospitals. Stool specimens/rectal swabs were collected and pathogen screening was performed on multiple platforms. Differences in pathogen detections between cases and controls, stratified by HIV status, were investigated. The majority (n = 164, 67.5%) of enrolled diarrhoeal cases with known HIV status were HIV-infected. Pathogens could be detected in 66.3% (n = 228) of specimens, with significantly higher detection in cases compared to controls (72.8% versus 50.5%, p<0.001). Amongst PLHIV, prevalence of Cystoisospora spp. was significantly higher in cases than controls (17.7% versus 0.0%, p = 0.028), while Schistosoma was detected more often in controls than cases (17.4% versus 2.4%, p = 0.009). Amongst the HIV-uninfected participants, prevalence of Shigella spp., Salmonella spp. and Helicobacter pylori was significantly higher in cases compared to controls (36.7% versus 12.0%, p = 0.002; 11.4% versus 0.0%, p = 0.012; 10.1% versus 0.0%, p = 0.023). Diarrhoeal aetiology differed by HIV status, with Shigella spp. (36.7%) and Salmonella spp. (11.4%) having the highest prevalence amongst HIV-uninfected cases and Shigella spp. (18.3%), Cystoisospora (17.7%), and Cryptosporidium spp. (15.9%) having the highest prevalence in cases amongst PLHIV. These differences should be considered for the development of diagnostic and treatment guidelines.

Relevance of biomarkers indicating gut damage and microbial translocation in people living with HIV

The intestinal barrier has the daunting task of allowing nutrient absorption while limiting the entry of microbial products into the systemic circulation. HIV infection disrupts the intestinal barrier and increases intestinal permeability, leading to microbial product translocation. Convergent evidence has shown that gut damage and an enhanced level of microbial translocation contribute to the enhanced immune activation, the risk of non-AIDS comorbidity, and mortality in people living with HIV (PLWH). Gut biopsy procedures are invasive, and are not appropriate or feasible in large populations, even though they are the gold standard for intestinal barrier investigation. Thus, validated biomarkers that measure the degree of intestinal barrier damage and microbial translocation are needed in PLWH. Hematological biomarkers represent an objective indication of specific medical conditions and/or their severity, and should be able to be measured accurately and reproducibly via easily available and standardized blood tests. Several plasma biomarkers of intestinal damage, i.e., intestinal fatty acid-binding protein (I-FABP), zonulin, and regenerating islet-derived protein-3α (REG3α), and biomarkers of microbial translocation, such as lipopolysaccharide (LPS) and (1,3)-β-D-Glucan (BDG) have been used as markers of risk for developing non-AIDS comorbidities in cross sectional analyses and clinical trials, including those aiming at repair of gut damage. In this review, we critically discuss the value of different biomarkers for the estimation of gut permeability levels, paving the way towards developing validated diagnostic and therapeutic strategies to repair gut epithelial damage and to improve overall disease outcomes in PLWH.

Assessment of independent comorbidities and comorbidity measures in predicting healthcare facility-onset Clostridioides difficile infection in Kenya

INTRODUCTION

Clostridioides difficile is primarily associated with hospital-acquired diarrhoea. The disease burden is aggravated in patients with comorbidities due to increased likelihood of polypharmacy, extended hospital stays and compromised immunity. The study aimed to investigate comorbidity predictors of healthcare facility-onset C. difficile infection (HO-CDI) in hospitalized patients.

METHODOLOGY

We performed a cross sectional study of 333 patients who developed diarrhoea during hospitalization. The patients were tested for CDI. Data on demographics, admission information, medication exposure and comorbidities were collected. The comorbidities were also categorised according to Charlson Comorbidity Index (CCI) and Elixhauser Comorbidity Index (ECI). Comorbidity predictors of HO-CDI were identified using multiple logistic regression analysis.

RESULTS

Overall, 230/333 (69%) patients had comorbidities, with the highest proportion being in patients aged over 60 years. Among the patients diagnosed with HO-CDI, 63/71(88.7%) reported comorbidities. Pairwise comparison between HO-CDI patients and comparison group revealed significant differences in hypertension, anemia, tuberculosis, diabetes, chronic kidney disease and chronic obstructive pulmonary disease. In the multiple logistic regression model significant predictors were chronic obstructive pulmonary disease (odds ratio [OR], 9.51; 95% confidence interval [CI], 1.8-50.1), diabetes (OR, 3.56; 95% CI, 1.11-11.38), chronic kidney disease (OR, 3.88; 95% CI, 1.57-9.62), anemia (OR, 3.67; 95% CI, 1.61-8.34) and hypertension (OR, 2.47; 95% CI, 1.-6.07). Among the comorbidity scores, CCI score of 2 (OR 6.67; 95% CI, 2.07-21.48), and ECI scores of 1 (OR, 4.07; 95% CI, 1.72-9.65), 2 (OR 2.86; 95% CI, 1.03-7.89), and ≥ 3 (OR, 4.87; 95% CI, 1.40-16.92) were significantly associated with higher odds of developing HO-CDI.

CONCLUSION

Chronic obstructive pulmonary disease, chronic kidney disease, anemia, diabetes, and hypertension were associated with an increased risk of developing HO-CDI. Besides, ECI proved to be a better predictor for HO-CDI. Therefore, it is imperative that hospitals should capitalize on targeted preventive approaches in patients with these underlying conditions to reduce the risk of developing HO-CDI and limit potential exposure to other patients.

Microbiome Studies in Non-human Primates

Purpose of Review

Observations of differing bacterial, intestinal microbiomes in people living with HIV have propelled interest in contributions of the microbiome to HIV disease. Non-human primate (NHP) models of HIV infection provide a controlled setting for assessing contributions of the microbiome by standardizing environmental confounders. We provide an overview of the findings of microbiome contributions to aspects of HIV disease derived from these animal models.

Recent Findings

Observations of differing bacterial, intestinal microbiomes are inconsistently observed in the NHP model following SIV infection. Differences in lentiviral susceptibility and vaccine efficacy have been attributed to variations in the intestinal microbiome; however, by-and-large, these differences have not been experimentally assessed.

Summary

Although compelling associations exist, clearly defined contributions of the microbiome to HIV and SIV disease are lacking. The empirical use of comprehensive multi-omics assessments and longitudinal and interventional study designs in NHP models is necessary to define this contribution more clearly.

Abdominal Pain in the Immunocompromised Patient

Abdominal pain in an immunocompromised patient represents a common clinical scenario that may have uncommon causes. Evaluation relies first on identifying the immunocompromise, whether due to congenital immunodeficiencies, malignancy, hematopoietic stem cell transplant, solid organ transplant, or human immunodeficiency virus/acquired immunodeficiency syndrome. Based on this determination, the emergency physician may then build a focused differential of pathophysiologic possibilities. Careful evaluation is necessary given the absence of classic physical examination findings, and liberal use of laboratory and cross-sectional imaging is prudent. Conservative evaluation and disposition of these high-risk patients is important to consider.

High Clostridium difficile Infection among HIV-Infected Children with Diarrhea in a Tertiary Hospital in Mwanza, Tanzania

Clostridium difficile causes a million of illnesses each year worldwide and can affect people of all ages. Limited data exist on the prevalence of C. difficile infections (CDI) among children below five years of age in developing countries. This study is aimed at determining the prevalence, associated factors, and outcome of the Clostridium difficile infection among children with diarrhea attending a tertiary hospital in Mwanza, Tanzania. Stool samples were collected and cultured anaerobically to isolate Clostridium difficile, followed by C. difficile toxin A and B assay and ribotyping. A total of 301 children with diarrhea were enrolled. A total of 22 (7.31%, 95% CI: 0.89-0.95) nonrepetitive stool samples were positive for Clostridium difficile. Eighteen (81%) of C. difficile isolates were toxigenic, and 16 (72.7%) had unknown ribotypes. Independent predictors of positive C. difficile were as follows: positive HIV status, hospital stay of more than four days, high stool leukocyte count, and watery stool. Clostridium difficile-positive children had significantly higher median duration of the diarrhea than those without C. difficile. Clinicians should consider C. difficile as a possible cause of diarrhea in children living in developing countries and institute appropriate management to prevent associated morbidities and mortalities. Furthermore, there is a need of joint effort to improve C. difficile diagnosis and surveillance in developing countries to establish the unknown epidemiology of CDI in these countries.

South African Society of Clinical Microbiology Clostridioides difficile infection diagnosis, management and infection prevention and control guideline

Clostridioides difficile infection (CDI) is a problem in both developed and developing countries and is a common hospital-acquired infection. This guideline provides evidence-based practical recommendations for South Africa and other developing countries. The scope of the guideline includes CDI diagnostic approaches; adult, paediatric and special populations treatment options; and surveillance and infection prevention and control recommendations.

Type 3 Immunity during Clostridioides difficile Infection: Too Much of a Good Thing?

Clostridioides (formerly known as Clostridium) difficile is the leading cause of hospital-acquired gastrointestinal infections in the United States and one of three urgent health care threats identified by the Centers for Disease Control and Prevention. C. difficile disease is mediated by the production of toxins that disrupt the epithelial barrier and cause a robust host inflammatory response. Studies in humans as well as animal models of disease have shown that the type of immune response generated against the infection dictates the outcome of disease, often irrespective of bacterial burden. Much of the focus on immunity during C. difficile infection (CDI) has been on type 3 immunity because of the established role for this arm of the immune system in other gastrointestinal inflammatory conditions such as inflammatory bowel disease (IBD). For example, interleukin-22 (IL-22) production by group 3 innate lymphoid cells (ILC3s) protects against pathobionts translocating across the epithelium during CDI. On the other hand, interleukin-17 (IL-17) production by Th17 cells increases CDI-associated mortality. Additionally, neutropenia has been associated with increased susceptibility to CDI in humans, but increased neutrophilia in mouse models correlates with host pathology. Taking the data together, these findings suggest dual roles for type 3 immune responses during infection. Here, we review the complex role of type 3 immunity during CDI and delineate what is known about innate and adaptive cellular immunity as well as the downstream effector cytokines known to be important during this infection.

2019 update of the WSES guidelines for management of Clostridioides (Clostridium) difficile infection in surgical patients

In the last three decades, Clostridium difficile infection (CDI) has increased in incidence and severity in many countries worldwide. The increase in CDI incidence has been particularly apparent among surgical patients. Therefore, prevention of CDI and optimization of management in the surgical patient are paramount. An international multidisciplinary panel of experts from the World Society of Emergency Surgery (WSES) updated its guidelines for management of CDI in surgical patients according to the most recent available literature. The update includes recent changes introduced in the management of this infection.

Clinical Review on the Utility of Fecal Microbiota Transplantation in Immunocompromised Patients

Fecal microbiota transplantation (FMT) represents a promising management modality for Clostridium difficile infection (CDI). In immunocompromised patients, FMT is utilized for CDI as well as emerging non-CDI indications such as inflammatory bowel disease and graft versus host disease. PURPOSE OF REVIEW: This review aims to shed light on the safety and efficacy of FMT in immunocompromised patients, including patients suffering for human immunodeficiency virus infection, solid organ and hematopoietic stem cell transplant recipients, cancer patients, and patients on immunosuppressive therapies. RECENT FINDINGS: Though the body of evidence concerning the use of FMT in immunocompromised is growing, no clinical trials exist to date. Present literature weighs in favor of FMT in immunocompromised patients, with an acceptable adverse effect profile and minimal risk of infectious adverse events. Further large scale studies and randomized controlled trials to validate the utility of FMT in immunocompromised individuals will be a welcomed endeavor.

Clostridium difficile infection in Johannesburg, South Africa

OBJECTIVES

The incidence of Clostridium difficile infection is increasing, resulting in significant in-patient morbidity and mortality. We describe the characteristics of Clostridium difficile infection in patients admitted to a tertiary Academic Hospital in Johannesburg, South Africa.

METHODS

This was a retrospective record review of 154 adult in-patients with confirmed Clostridium difficile infection undertaken between 1 January 2013 and 30 June 2014.

RESULTS

Overall, 83 (53.9%) patients were female and the median age was 39 years. The most common symptoms were watery diarrhea (92.9%) and fever (27.3%). Overall, 145 (97.9%) patients had been exposed to antibiotics in the last 30 days, 54 (35.1%) to immunosuppressives, 48 (31.2%) to gastric acid suppressants, and 65 (42.2%) patients had previous hospital admissions. Only two cases were community-acquired. In total, 73 (47.4%) patients died. There was no difference in outcomes of HIV-positive patients compared to HIV-negative patients; however, the clinical features were more marked in the HIV-negative patients. Non-survivors tended to have a greater number of severity indicators compared to the survivors.

CONCLUSION

Patients with Clostridium difficile infection in this study were younger and had a higher mortality than that reported in the Western world. Most infections were hospital-acquired.

Risk factors for Clostridium difficile infection in HIV-infected patients

BACKGROUND

Clostridium difficile infection is a healthcare-associated infection resulting in significant morbidity. Although immunosuppression is associated with Clostridium difficile infection acquisition and adverse outcomes, the epidemiology of Clostridium difficile infection in HIV-infected patients has been little studied in the era of antiretroviral therapy. This study identifies the risk factors for acquisition of Clostridium difficile infection in HIV-infected patients.

METHODS

A retrospective, propensity score-matched case-control study design was employed, with patients selected from our institution's outpatient HIV clinic. Clostridium difficile infection cases were defined as having positive stool testing plus an appropriate clinical presentation. The propensity score was generated via multiple logistic regression from year of HIV diagnosis, age at first contact, duration of follow-up, gender, and initial CD4 count.

RESULTS

The 46 cases included were matched to a total of 180 controls. Prior antibiotic treatment was a significant predictor of Clostridium difficile infection (odds ratio: 13, 95% confidence interval: 3.49-48.8, p < .001) as was number of hospital admissions in the preceding year (odds ratio: 4.02, confidence interval: 1.81-8.94, p < .001). Having both proton pump inhibitor use and CD4 count <200 cells/µL significantly increased odds of Clostridium difficile infection in the multivariable model (odds ratio: 15.17, confidence interval: 1.31-175.9, p = .021).

CONCLUSION

As in the general population, frequent hospitalizations and exposure to antimicrobials are independent predictors of Clostridium difficile infection acquisition in patients with HIV. Additionally, low CD4 count and proton pump inhibitor use are new potentially modifiable variables that can be targeted for prevention of Clostridium difficile infection in future interventional studies.

Selected Topics in Anaerobic Bacteriology

Alteration in the host microbiome at skin and mucosal surfaces plays a role in the function of the immune system, and may predispose immunocompromised patients to infection. Because obligate anaerobes are the predominant type of bacteria present in humans at skin and mucosal surfaces, immunocompromised patients are at increased risk for serious invasive infection due to anaerobes. Laboratory approaches to the diagnosis of anaerobe infections that occur due to pyogenic, polymicrobial, or toxin-producing organisms are described. The clinical interpretation and limitations of anaerobe recovery from specimens, anaerobe-identification procedures, and antibiotic-susceptibility testing are outlined. Bacteriotherapy following analysis of disruption of the host microbiome has been effective for treatment of refractory or recurrent Clostridium difficile infection, and may become feasible for other conditions in the future.

Colorectal Surgery in Patients with HIV and AIDS: Trends and Outcomes over a 10-Year Period in the USA

BACKGROUND

HIV has become a chronic disease, which may render this population more prone to developing the colorectal pathologies that typically affect older Americans.

METHODS

A retrospective review of the Nationwide Inpatient Sample was performed to identify patients who underwent colon and rectal surgery from 2001 to 2010. Multivariate analysis was used to evaluate outcomes among the general population, patients with HIV, and patients with AIDS.

RESULTS

Hospital admissions for colon and rectal procedures of patients with HIV/AIDS grew at a faster rate than all-cause admissions of patients with HIV/AIDS, with mean yearly increases of 17.8 and 2.1 %, respectively (p < 0.05). Patients with HIV/AIDS undergoing colon and rectal operations for cancer, polyps, diverticular disease, and Clostridium difficile were younger than the general population (51 vs. 65 years; p < 0.01). AIDS was independently associated with increased odds of mortality (OR 2.11; 95 % CI 1.24, 3.61), wound complications (OR 1.53; 95 % CI 1.09, 2.17), and pneumonia (OR 2.02; 95 % CI 1.33, 3.08). Risk-adjusted outcomes of colorectal surgery in patients with HIV did not differ significantly from the general population.

CONCLUSION

Postoperative outcomes in patients with HIV are similar to the general population, while patients with AIDS have a higher risk of mortality and certain complications.

HIV-Helicobacter pylori Co-Infection: Antibiotic Resistance, Prevalence, and Risk Factors

Background

Patients infected with human immunodeficiency virus (HIV) are living longer due to the availability of more potent treatments. However, prescription of antibiotics to treat or prevent infections in these patients may increase the likelihood of co-infection with antibiotic-resistant species.

Aim

To compare antimicrobial susceptibility of Helicobacter pylori (H. pylori) in HIV-positive and HIV-negative patients and assess risk-factors for resistance.

Methods

We prospectively collected data from consecutive HIV-positive and HIV-negative patients undergoing upper gastrointestinal endoscopy. Patients with H. pylori-positive gastric biopsies who had never received H. pylori treatment were included.

Results

Of the 353 patients included, 93 were HIV-positive and 260 HIV-negative. Among the HIV-positive patients, 56 (60%) had been infected for <10 years, the median CD4+ count was 493 cells/μl and median viral load was 61 copies/mL; 66 (71%) were receiving antiretroviral therapy. HIV-positive patients were more often male (p = 0.009), had a lower body mass index (p<0.0001), and had less frequently received antibiotics during the 12-months prior to the endoscopy (p<0.0001) than HIV-negative patients. HIV-positive patients were more likely to have H. pylori resistant to levofloxacin (p = 0.0004), metronidazole (p = 0.01), or multiple antibiotics (p = 0.006). HIV-positive Black Africans were more likely to have resistant strains than were HIV-negative Black Africans (p = 0.04). Ethnicity and HIV status were independent risk factors for H. pylori resistance in all patients and acquired immune deficiency syndrome (AIDS) and sex were risk factors in HIV-positive patients.

Conclusions

There was a higher prevalence of primary H. pylori-resistant strains in HIV-positive than in HIV-negative patients. AIDS and sex were predictors of H. pylori resistance in HIV-positive patients.

WSES guidelines for management of Clostridium difficile infection in surgical patients

In the last two decades there have been dramatic changes in the epidemiology of Clostridium difficile infection (CDI), with increases in incidence and severity of disease in many countries worldwide. The incidence of CDI has also increased in surgical patients. Optimization of management of C difficile, has therefore become increasingly urgent. An international multidisciplinary panel of experts prepared evidenced-based World Society of Emergency Surgery (WSES) guidelines for management of CDI in surgical patients.

Fecal microbiota transplantation (FMT) for Clostridium difficile infection: focus on immunocompromised patients

Clostridium difficile infection (CDI) is an emerging problem worldwide associated with significant morbidity, mortality, recurrence rates and healthcare costs. Immunosuppressed patients, including HIV-seropositive individuals, solid organ transplant recipients, patients with malignancies, hematopoietic stem cell transplant recipients, and patients with inflammatory bowel disease are increasingly recognized as being at higher risk of developing CDI where it may be associated with significant complications, recurrence, and mortality. Fecal microbiota transplantation (FMT) has proven to be an effective and safe procedure for the treatment of recurrent or refractory CDI in immunocompetent patients by restoring the gut microbiota and resistance to further recurrences. During the last two years the first data on FMT in immunocompromised patients began to appear in the medical literature. Herein we summarize the use of FMT for the treatment of CDI with a focus on immunocompromised patients.

Early infection of hip joint prosthesis by Clostridium difficile in an HIV-1 infected patient

Anaerobes are less frequently described as causative pathogen of prosthetic joint infection (PJI). We report the first case of early PJI after hip arthroplasty due to Clostridium difficile in a diabetic and HIV-1 infected patient with bacteremia. Our patient was successfully treated through surgical debridement and prosthesis retention combined with targeted antibiotic therapy.