Design and validation of Dolosigranulum pigrum specific PCR primers using the bacterial core genome.

Dolosigranulum pigrum-a lactic acid bacterium that is increasingly recognized as an important member of the nasal microbiome. Currently, there are limited rapid and low-cost options for confirming D. pigrum isolates and detecting D. pigrum in clinical specimens. Here we describe the design and validation of a novel PCR assay targeting D. pigrum that is both sensitive and specific. We designed a PCR assay targeting murJ, a single-copy core species gene identified through the analysis of 21 D. pigrum whole genome sequences. The assay achieved 100% sensitivity and 100% specificity against D. pigrum and diverse bacterial isolates and an overall 91.1% sensitivity and 100% specificity using nasal swabs, detecting D. pigrum at a threshold of 1.0 × 104 D. pigrum 16S rRNA gene copies per swab. This assay adds a reliable and rapid D. pigrum detection tool to the microbiome researcher toolkit investigating the role of generalist and specialist bacteria in the nasal environment.

Geographic variability of antibiotic prescribing for acute respiratory tract infections within a direct-to-consumer telemedicine practice.

In this retrospective cohort study of patients presenting to a national direct-to-consumer medical practice, we found that provider geographic location is a stronger driver of antibiotic prescribing than patient location. Physicians in the Northeast and South are significantly more likely than physicians in the West to prescribe antibiotics for upper respiratory infection and bronchitis.

The Penis, the Vagina and HIV Risk: Key Differences (Aside from the Obvious).

Globally, most Human Immunodeficiency Virus type 1 (HIV) transmission occurs through vaginal-penile sex (heterosexual transmission). The local immune environment at the site of HIV exposure is an important determinant of whether exposure during sex will lead to productive infection, and the vaginal and penile immune milieus are each critically shaped by the local microbiome. However, there are key differences in the microbial drivers of inflammation and immune quiescence at these tissue sites. In both, a high abundance of anaerobic taxa (e.g., Prevotella) is associated with an increased local density of HIV target cells and an increased risk of acquiring HIV through sex. However, the taxa that have been associated to date with increased risk in the vagina and penis are not identical. Just as importantly, the microbiota associated with comparatively less inflammation and HIV risk-i.e., the optimal microbiota-are very different at the two sites. In the vagina, Lactobacillus spp. are immunoregulatory and may protect against HIV acquisition, whereas on the penis, "skin type" flora such as Corynebacterium are associated with reduced inflammation. Compared to its vaginal counterpart, much less is known about the dynamics of the penile microbiome, the ability of clinical interventions to alter the penile microbiome, or the impact of natural/induced microbiome alterations on penile immunology and HIV risk.

SARS-CoV-2 surveillance and outbreak response on an urban American college campus.

OBJECTIVE: The George Washington University (GW) in Washington, D.C., USA established the Public Health Laboratory and Campus COVID-19 Support Team (CCST) to develop and implement its SARS-CoV-2 surveillance testing and outbreak response for the 2020-2021 academic year. PARTICIPANTS AND METHODS: Approximately 4,000 GW members had access to campus for living accommodations, limited in-person instruction, athletics, research, and university operations. The outbreak response included daily risk assessment surveys, weekly surveillance testing, symptomatic and voluntary testing, case investigation, and contact tracing. RESULTS: Between August 17 - November 24, 2020, 42,350 SARS-CoV-2 PCR tests were performed, and 194 (0.46%) of tests were positive. Surveillance testing identified 59 (30.4%); voluntary testing 97 (50%); and symptomatic testing 30 (15.5%) of the cases, respectively. CONCLUSIONS: Robust testing of asymptomatic people and rapid isolation and quarantine of members who are exposed or infected effectively limited the spread of SARS-CoV-2 during the Fall 2020 semester.