Does active hepatitis C virus infection increase the risk for infection due to Staphylococcus aureus?

Prospects on Repurposing a Live Attenuated Vaccine for the Control of Unrelated Infections

Live vaccines use attenuated microbes to acquire immunity against pathogens in a safe way. As live attenuated vaccines (LAVs) still maintain infectivity, the vaccination stimulates diverse immune responses by mimicking natural infection. Induction of pathogen-specific antibodies or cell-mediated cytotoxicity provides means of specific protection, but LAV can also elicit unintended off-target effects, termed non-specific effects. Such mechanisms as short-lived genetic interference and non-specific innate immune response or long-lasting trained immunity and heterologous immunity allow LAVs to develop resistance to subsequent microbial infections. Based on their safety and potential for interference, LAVs may be considered as an alternative for immediate mitigation and control of unexpected pandemic outbreaks before pathogen-specific therapeutic and prophylactic measures are deployed.

Impact of Chronic Hepatitis C virus co-infection on outcomes of infective endocarditis in people who inject drugs

Injection drug use (IDU) is a risk factor for infective endocarditis (IE) and hepatitis C virus (HCV) infection. This retrospective cohort study assessed HCV's impact on outcomes of adult people who inject drugs (PWID). Those admitted due to IE using modified Duke criteria from January 2012 through May 2018 were identified. The cohort was divided into HCV seropositive and seronegative groups. The seropositive group was further stratified according to HCV viremia. Complications and mortality during the IE hospitalization, at 10 weeks, and 1 year were compared across groups. Clinical factors were similar between the cohorts, except patients without viremia (29, 81%) required more ICU admissions than with viremia (30, 60%) (P < 0.05). There was no difference in mortality at all time periods between the groups. Although several factors affect mortality in PWID with IE, neither HCV antibody positivity nor viremia appear to increase the risk for complications or death.

Computational insight into the protective mechanism of Allium iranicum Wendelbo. Alliaceae in a mouse model of Staphylococcosis: focus on dietary phytocannabinoid trans-caryophyllene

This study was aimed to investigate the prophylactic effects of hydro-alcoholic extract derived from bulbs of Allium iranicum Wendelbo. (Alliaceae; AI) on mouse model of Staphylococcosis, and to decipher which phytochemicals of AI may involve in its anti-staphylococcal property. Male mice were allocated into four groups, i.e. normal control (NC) and three other groups received AI at 0.192, 0.384 and 0.768 mg/ml in drinking water for 9 days. Thereafter, mice were intravenously injected 106 colony forming unites (CFUs/ml) of Staphylococcus aureus suspension at 10th day and tissue homogenates were colony counted for S. aureus 9 days post-inoculation. Molecular docking among cardinal proteins involved in Staphylococcosis and phytochemicals of AI has been performed using PyRx software and the best ligand submitted to compute molecular and biological attributes. Induction of murine Staphylococcosis and inclusion of AI did not adversely alter bodyweights of mice while colony counts in selected tissues of mice infected with S. aureus were different among groups (PANOVA = 0.016). Generally, the colony counts tended to decrease in AI 0.192 (P = 0.099) and AI 0.768 (P = 0.818) groups as compared to NC, however AI 0.384 (P = 0.005) group showed lesser colony counts than NC. In addition, colony counts decreased in AI 0.384 as compared to AI 0.768 (P = 0.009). The colony counts in kidneys of AI 0.0384 group were lesser than those of NC (P = 0.051) and AI 0.768 (P = 0.048). Among target proteins, trans-caryophyllene (TCP) showed reliable binding affinities (kcal/mol) to three hydrolase enzymes [beta toxin (sphingomyelin phosphodiesterase - 8.1), sortase B (protease - 8.1), and FtsZ (GTPase - 8.7) of S. aureus]. The ADMET properties of TCP showed that it followed the Lipinski's rule of five with one violation with respect to its miLogP 5.17. In addition, Molinspiration bioactivity score indicated ion channel modulatory and enzyme inhibitory effect for TCP. Computational findings of admetSAR software revealed that TCP leads to carcinogenicity, Tetrahymena pyriformis, fish, rat, and honey bee toxicities, weak inhibition of human ether-a-go-go-related gene, and cytochromes inhibitory promiscuity. The TCP showed promising in human intestinal absorption, blood-brain barrier permeability, Caco-2 penetration, and solubility. The results of Toxtree software showed that TCP is not an endogenous molecule of the body and contains no functional groups associated with enhanced toxicity and considered as class I toxic compound close to terpenes. In conclusion, we found the hydro-alcoholic extract derived from of bulbs AI has a significant protective effect against Staphylococcosis in mouse model. In silico findings demonstrated that TCP has acceptable ADMET score to be considered as a bioactive compound for designing phytobiotics.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s40203-021-00078-x.

Epidemiological Trend of Sepsis in Patients with Hospital Admissions Related to Hepatitis C in Spain (2000-2015): A Nationwide Study

Background: Hepatitis C virus (HCV) infection predisposes patients to other infectious diseases, such as sepsis. We aimed to analyze epidemiological trends of sepsis-related admissions, deaths, and costs in hospital admissions with chronic hepatitis C who had a hospital admission in Spain. Methods: We performed a retrospective study of all hospitalizations involving chronic hepatitis C in the Spanish Minimum Basic Data Set (MBDS) between 2000 and 2015. This period was divided into four calendar periods (2000–2004, 2005–2007, 2008–2011, and 2012–2015). Results: We selected 868,523 hospital admissions of patients with chronic hepatitis C over 16 years in the Spanish MBDS. Among them, we found 70,976 (8.17%) hospital admissions of patients who developed sepsis, of which 13,915 (19.61%) died during admission. We found an upward trend, from 2000–2003 to 2012–2015, in the rate of sepsis-related admission (from 6.18% to 10.64%; p < 0.001), the risk of sepsis-related admission (from 1.31 to 1.55; p < 0.001), and the sepsis-related cost per hospital admission (from 7198€ to above 9497€; p < 0.001). However, we found a downward trend during the same study period in the sepsis case-fatality rate (from 21.99% to 18.16%; p < 0.001), the risk of sepsis-related death (from 0.81 to 0.56; p < 0.001), and the length of hospital stay (LOHS) (from 16.9 to 13.9; p < 0.001). Moreover, the rate of bacterial Gram-positive and candidiasis infections decreased, while Gram-negative microorganisms increased from 2000–2003 to 2012–2015. Conclusions: Sepsis, in chronic hepatitis C patients admitted to the hospital, has increased the period 2000–2015 and has been an increasing burden for the Spanish public health system. However, there has also been a significant reduction in lethality and LOHS during the study period. In addition, the most prevalent specific microorganisms have also changed in this period.

Incidence of hospitalization for infection among patients with hepatitis B or C virus infection without cirrhosis in Taiwan: A cohort study

BACKGROUND

Infection is a major complication in liver cirrhosis and causes major morbidity and mortality. However, the incidence and mortality related to these conditions in patients infected with hepatitis C virus (HCV) are unclear, as is whether antiviral therapy could change their infection risk.

METHODS AND FINDINGS

In this community-based cohort study, a total of 115,336 adults (mean age 52.2 years; 35.6% men) without cirrhosis participating in the New Taipei City Health Screening in 2005-2008 were classified as having noncirrhotic HCV (NC-HCV) (n = 2,839), noncirrhotic hepatitis B virus (NC-HBV) (n = 8,316), or no HBV or HCV infection (NBNC) (n = 104,181). Participants were followed to their first hospitalization for infection or death after data linkage with the Taiwan National Health Insurance Research Database (NHIRD) and Death Registry. A Cox proportional hazard regression model, adjusted for age, sex, body mass index (BMI), smoking, alcohol consumption, education level, diabetes, renal function, systemic steroids, and history of hospitalization, was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for overall and individual sites of infection and infection-related mortality. The reference group was NBNC participants with normal to mildly elevated alanine aminotransferase (ALT) (<1.5 times upper normal limit [UNL]) levels. To further address the impact of antiviral treatment on infection risk, we conducted analyses of data from the nationwide NHIRD and compared the risks for hospitalization because of infections and infection-related deaths between patients with HCV who received antiviral therapy (n = 20,264) and those who remained untreated (n = 104,360). During a median 8.2-year follow-up, the incidence of hospitalization for infection was substantially higher in NC-HCV patients. Compared to the reference group, NC-HCV was associated with a significantly higher risk for hospitalization because of overall infections (adjusted HR: 1.22; 95% CI: 1.12-1.33), but we observed no increased risk for patients in the NC-HBV (adjusted HR: 0.94; 95% CI: 0.88-1.01) or NBNC group with moderate to markedly elevated ALT levels (adjusted HR: 1.03; 95% CI: 0.93-1.14). For specific sites of infection, the NC-HCV group had increased risks for septicemia and lower respiratory tract, reproductive, and urinary tract infections. We noted no increased risk for infection-related death among patients with NC-HCV. Patients with HCV who received antiviral therapy had significantly reduced infection-related hospitalization and death risks (adjusted HR: 0.79; 95% CI: 0.73-0.84 for infection-related hospitalization and adjusted HR: 0.08; 95% CI: 0.04-0.16 for infection-related deaths). Study limitations include the exclusion of patients with cirrhosis from the cohort, the possibility of unmeasured confounding, and the lack of information on direct-acting antiviral agents (DAAs).

CONCLUSIONS

In this study, patients with NC-HCV were at increased risk for hospitalization for infection, while no increased risk was observed for NC-HBV-infected patients.

Incidence Rates and Risk of Hospital Registered Infections among Schizophrenia Patients before and after Onset of Illness: A Population-Based Nationwide Register Study

Infections in schizophrenia patients are associated with an increased premature mortality. However, our knowledge about the burden of infections in schizophrenia is scarce. The aims of this study were to (1) determine the prevalence of clinically important hospital registered infections in the period of five years prior to and five years after the diagnosis, (2) estimate the risk of infections before and after the schizophrenia diagnosis and, (3) evaluate the impact of comorbidity on the risk of infections in schizophrenia. Using combined data from Danish national registers, we sampled a cohort of all persons born in Denmark in the period 1975⁻1990 and obtained health-related records from 1995⁻2013. Occurrence patterns and the risk of infections were measured as annual incidence rates and incidence rates ratios, estimated using Poisson models. Medical conditions from the Charlson Index were considered as a measure of comorbidity. The analyses showed that schizophrenia patients had a significantly elevated risk of almost all types of hospital registered infections during the period of the study when compared to the controls. Comorbidity increased rates of infections by 176%. The results suggest that the risk of infections is elevated in the schizophrenia population and physical illness is an important risk factor.

The pathogenesis of Staphylococcus aureus in autoimmune diseases

Autoimmune disease are defined as the attacks on host tissue by the immune system. Several factors, e.g. genetic and environmental triggers (in particular, viruses, bacteria, and other infectious pathogens) play a role in the development of autoimmune diseases. Bacterial infections are related to several autoimmune diseases, e.g. chronic inflammations and demyelination. Nowadays, an estimated 20-30% of the general human population carry Staphylococcus aureus (S. aureus). This organism can asymptomatically colonize healthy individuals. S. aureus carriers show no sign of infection and can thus spread this bacterium in the community. Several studies investigated the potential involvement of this bacterium as the etiological agents of autoimmune diseases. The present review focused on the role of S. aureus infections in the pathogenesis of autoimmune, inflammatory, and demyelinating diseases. Possible modes of the pathogenic action of bacteria are discussed in association with the ways in which S. aureus can initiate or exacerbate autoimmunity.