Differential Signature of the Microbiome and Neutrophils in the Oral Cavity of HIV-Infected Individuals.

HIV infection is associated with a wide range of changes in microbial communities and immune cell components of the oral cavity. The purpose of this study was to evaluate the oral microbiome in relationship to oral neutrophils in HIV-infected compared to healthy individuals. We evaluated oral washes and saliva samples from HIV-infected individuals (n=52) and healthy controls (n=43). Using 16S-rRNA gene sequencing, we found differential ß-diversity using Principal Coordinate Analysis (PCoA) with Bray-Curtis distances. The α-diversity analysis by Faith's, Shannon, and observed OTUs indexes indicated that the saliva samples from HIV-infected individuals harbored significantly richer bacterial communities compared to the saliva samples from healthy individuals. Notably, we observed that five species of Spirochaeta including Spirochaetaceae, Spirochaeta, Treponema, Treponema amylovorum, and Treponema azotonutricum were significantly abundant. In contrast, Helicobacter species were significantly reduced in the saliva of HIV-infected individuals. Moreover, we found a significant reduction in the frequency of oral neutrophils in the oral cavity of HIV-infected individuals, which was positively related to their CD4+ T cell count. In particular, we noted a significant decline in CD44 expressing neutrophils and the intensity of CD44 expression on oral neutrophils of HIV-infected individuals. This observation was supported by the elevation of soluble CD44 in the saliva of HIV-infected individuals. Overall, the core oral microbiome was distinguishable between HIV-infected individuals on antiretroviral therapy compared to the HIV-negative group. The observed reduction in oral neutrophils might likely be related to the low surface expression of CD44, resulting in a higher bacterial diversity and richness in HIV-infected individuals.

Bartonella quintana infective endocarditis in northern Alberta: A case report.

We present a case of Bartonella quintana infective endocarditis requiring valvular surgery in an Indigenous patient from northern Alberta that was identified months after initial presentation to hospital with undifferentiated laboratory abnormalities. Syndromes caused by B. quintana are often challenging to diagnose due to their non-specific presentation and the difficulty in detecting this organism using traditional culture methods. Additionally, risk factors for B. quintana include marginal housing and alcohol use disorder, which often impede access to health care. Indigenous patients in northern Canada often face worse health outcomes compared with other regions owing to poor economic conditions, substandard housing, and limited access to health care resources. Given that risk factors for B. quintana are prevalent throughout northern Canada and that this infection is difficult to diagnose, we surmise that the prevalence of B. quintana infection is underestimated in northern Canada.

Les auteurs présentent un cas d'endocardite infectieuse à Bartonella quintana exigeant une chirurgie valvulaire chez un patient autochtone du nord de l'Alberta, dépisté des mois après la première consultation à l'hôpital, alors que les anomalies de laboratoires étaient indifférenciées. Les syndromes causés par le Bartonella quintana sont souvent difficiles à diagnostiquer à cause de leur présentation non spécifique et de la difficulté à déceler cet organisme au moyen des méthodes de culture classiques. De plus, les facteurs de risque de Bartonella quintana incluent des logements inférieurs aux normes et des troubles de l'usage de l'alcool, qui nuisent souvent à l'accès aux soins. Les patients autochtones du nord du Canada présentent souvent des résultats cliniques pires que ceux d'autres régions à cause des mauvaises conditions économiques, des logements inférieurs aux normes et de l'accès limité aux ressources de santé. Puisque les facteurs de risque de Bartonella quintana prévalent dans tout le nord du Canada et que cette infection est difficile à diagnostiquer, les auteurs postulent que la prévalence d'infection à Bartonella quintana est sous-estimée dans cette région.