Staphylococcal bacteraemia among human immunodeficiency virus positive patients at a screening center in Lagos, Nigeria

Plasma Virome of HIV-infected Subjects on Suppressive Antiretroviral Therapy Reveals Association of Differentially Abundant Viruses with Distinct T-cell Phenotypes and Inflammation

Background

The plasma virome represents the overall composition of viral sequences present in it. Alteration in plasma virome has been reported in treatment naïve and immunocompromised (CD4 count < 200) people with HIV (PWH). However, the effect of ART on virome composition in PWH on ART with preserved CD4 counts is poorly understood.

Objectives

We aimed to assess the alterations in plasma virome in PWH on ART in comparison to HIV-negative uninfected controls and to further investigate possible associations of plasma viruses with inflammation and immune dysfunction, namely, immunosenescence and immune exhaustion.

Methods

Plasma viral DNA from PWH on ART and controls was used for sequencing on the Illumina Nextseq500 platform, followed by the identification of viral sequences using an automated pipeline, VIROMATCH. Multiplex cytokine assay was performed to measure the concentrations of various cytokines in plasma. Immunophenotyping was performed on PBMCs to identify T cell markers of immunosenescence and immune exhaustion.

Results

In our observational, cross-sectional pilot study, chronically infected PWH on ART had significantly different viral species compositions compared to controls. The plasma virome of PWH showed a significantly high relative abundance of species Human gammaherpesvirus 4, also known as Epstein-Barr virus (EBV). Moreover, EBV emerged as a significant viral taxon differentially enriched in PWH on ART, which further correlated positively with the exhaustion phenotype of T cells and significantly increased TNF-α in PWH on ART. Additionally, a significantly increased proportion of senescent T cells and IL-8 cytokine was detected in PWH on ART.

Conclusion

Altered plasma virome influenced the inflammatory response and T-cell phenotype in PWH on ART.

The Role of the Oral Immune System in Oropharyngeal Candidiasis-Facilitated Invasion and Dissemination of Staphylococcus aureus

Candida albicans and Staphylococcus aureus account for most invasive fungal and bacterial bloodstream infections (BSIs), respectively. However, the initial point of invasion responsible for S. aureus BSIs is often unclear. Recently, C. albicans has been proposed to mediate S. aureus invasion of immunocompromised hosts during co-colonization of oral mucosal surfaces. The status of the oral immune system crucially contributes to this process in two distinct ways: firstly, by allowing invasive C. albicans growth during dysfunction of extra-epithelial immunity, and secondly following invasion by some remaining function of intra-epithelial immunity. Immunocompromised individuals at risk of developing invasive oral C. albicans infections could, therefore, also be at risk of contracting concordant S. aureus BSIs. Considering the crucial contribution of both oral immune function and dysfunction, the aim of this review is to provide an overview of relevant aspects of intra and extra-epithelial oral immunity and discuss predominant immune deficiencies expected to facilitate C. albicans induced S. aureus BSIs.

The global and regional prevalence, burden, and risk factors for methicillin-resistant Staphylococcus aureus colonization in HIV-infected people: A systematic review and meta-analysis

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) is among the most important opportunistic pathogens in HIV+ patients, resulting in considerable morbidity and mortality.

METHODS

The MEDLINE, Scopus, Web of Science, and EMBASE databases were comprehensively searched for studies that investigated the prevalence of MRSA colonization in HIV+ patients. We used a random effects model to calculate pooled prevalence estimates with 95% confidence intervals (CI) and analyzed data based on World Health Organization regions.

RESULTS

Among 9,772 records identified, 69 were included in the meta-analysis, comprising 30,050 HIV+ patients from 21 countries. We estimated the pooled worldwide prevalence of MRSA in people living with HIV to be 7% (95% CI 5%-9%, 1,623/30,050), with the highest prevalence in Southeast Asia (16%, 95% CI 9%-24%) and the region of the Americas (10%; 95% CI 7%-13%) and lowest prevalence in the European region (1%; 95% CI 0%-1%). Globally, we estimated approximately 2,659,000 (95% CI 1,835,000-3,303,000) HIV+ patients with colonized MRSA. Potential risk factors for MRSA colonization in HIV+ patients included previous MRSA infection (OR, 7.5; 95% CI, 3.91-14.37), hospitalization in the past year (OR, 1.87; 95% CI 1.11-3.16), and use of antibiotics (OR, 2.52; 95% CI 1.39-4.58).

CONCLUSIONS

Our findings emphasize the importance of routine screening for MRSA among all HIV+ patients throughout the world, especially in regions that have a high burden of disease.