Sinus microbiome diversity depletion and Corynebacterium tuberculostearicum enrichment mediates rhinosinusitis

Chronic rhinosinusitis in children

Chronic rhinosinusitis (CRS) affects nearly 37 million people in the United States each year and accounts for approximately $6 billion in direct and indirect health care costs. Despite its prevalence and significant impact, little is known about its exact cause and pathophysiology, and significant controversy remains regarding appropriate treatment options. Basic science research, however, has shown recent promise toward improving understanding of the innate and environmental factors underlying the pathophysiology of CRS. The hope is that this will also lead to advances in treatment for children adversely affected by this common yet complicated disease.

Medical therapy reduces microbiota diversity and evenness in surgically recalcitrant chronic rhinosinusitis

BACKGROUND

Chronic rhinosinusitis (CRS) is a highly prevalent and heterogeneous condition frequently treated with antibiotics and corticosteroid therapy. However, the effect of medical therapy on sinus microbiota remains unknown.

METHODS

We enrolled CRS patients (n = 6) with patent maxillary antrostomies and active mucosal inflammation, who had not received antibiotics or corticosteroids in the previous 8 weeks. A pretreatment and posttreatment maxillary sinus swab was collected, from which DNA was extracted, pyrosequenced, and analyzed using a naïve Bayesian classifier and ecological analyses.

RESULTS

Four patients showed significant improvement in endoscopic appearance. The shifts in microbiota in response to therapy were highly individualized. There was no single common microbiota profile among patients with similar clinical outcomes, but overall there was significant decrease in microbiota diversity (t(5) = 2.05, p = 0.10) and evenness (t(5) = 2.28, p = 0.07) after treatment.

CONCLUSION

Our findings strongly correlate with earlier studies that examined the impact of antibiotics on human microbiota. We observed that posttreatment, patients frequently became colonized by taxa that are less susceptible to the prescribed antibiotics. Our findings highlight the challenge in seeking generalizable diagnostic and therapeutic options in CRS, particularly regarding microbiological response and outcomes.

Tuning of skin immunity by skin commensal bacteria

Evaluation of: Naik S, Bouladoux N, Wilhelm C et al. Compartmentalized control of skin immunity by resident commensals. Science 337, 1115-1119 (2012). Most analyses of commensal microbiota have been directed toward the gut microbiota and its role in the development of the intestinal immune system, and in regulating the immune response at sites distant from the gut, including the joints or CNS. However, very little is known about how other niches of commensal microbiota affect local immunity and whether they are influenced by the gut microbiota. The current paper reveals that skin commensals are required for the development of protective immunity against a cutaneous pathogen. This immune response driven by skin commensals occurs independently of the gut microbiota and is mediated by MyD88 and IL-1 signaling that promotes protective effector T-cell responses.

From in vitro to in vivo Models of Bacterial Biofilm-Related Infections

The influence of microorganisms growing as sessile communities in a large number of human infections has been extensively studied and recognized for 30–40 years, therefore warranting intense scientific and medical research. Nonetheless, mimicking the biofilm-life style of bacteria and biofilm-related infections has been an arduous task. Models used to study biofilms range from simple in vitro to complex in vivo models of tissues or device-related infections. These different models have progressively contributed to the current knowledge of biofilm physiology within the host context. While far from a complete understanding of the multiple elements controlling the dynamic interactions between the host and biofilms, we are nowadays witnessing the emergence of promising preventive or curative strategies to fight biofilm-related infections. This review undertakes a comprehensive analysis of the literature from a historic perspective commenting on the contribution of the different models and discussing future venues and new approaches that can be merged with more traditional techniques in order to model biofilm-infections and efficiently fight them.