Genome Sequence of \u3cem\u3eBacillus\u3c/em\u3e Phage Saddex

The complete genome of Bacillus phage Saddex was determined and annotated in this study. Saddex has distinct sections with similarities to other Bacillus phages, such as Kida, even though these phages were isolated more than 800 km apart by separate laboratories

SARS‑CoV‑2 entry into and evolution within a skilled nursing facility

SARS-CoV-2 belongs to the family Coronaviridae which includes multiple human pathogens that have an outsized impact on aging populations. As a novel human pathogen, SARS-CoV-2 is undergoing continuous adaptation to this new host species and there is evidence of this throughout the scientific and public literature. However, most investigations of SARS-CoV-2 evolution have focused on largescale collections of data across diverse populations and/or living environments. Here we investigate SARS-CoV-2 evolution in epidemiologically linked individuals within a single outbreak at a skilled nursing facility beginning with initial introduction of the pathogen. The data demonstrate that SARSCoV- 2 was introduced to the facility multiple times without establishing an interfacility transmission chain, followed by a single introduction that infected many individuals within a week. This largescale introduction by a single genotype then persisted in the facility. SARS-CoV-2 sequences were investigated at both the consensus and intra-host variation levels. Understanding the variability in SARS-CoV-2 during transmission chains will assist in understanding the spread of this disease and can ultimately inform best practices for mitigation strategies

Barcoded viruses mimic virus population dynamics during transmission and infection events.

(A) Intrahost bottlenecks in Ae. aegypti rapidly reduce the complexity of a bcZIKV population during mosquito infection. (B) A more complex bcIAV population is transmitted between ferrets via contact infection than airborne infection. (Created with Biorender.com)</p

Barcoded viruses are highly effective mimics of RNA virus mutant swarms.

Marked clones and barcoded viruses allow investigators to study changes to population diversity in a variety of systems without the variable fitness observed between viruses in natural RNA virus swarms. (Created with Biorender.com).</p

Loss of West Nile virus genetic diversity during mosquito infection due to species-dependent population bottlenecks

Summary: Vector competence (VC) refers to the efficiency of pathogen transmission by vectors. Each step in the infection of a mosquito vector constitutes a barrier to transmission that may impose bottlenecks on virus populations. West Nile virus (WNV) is maintained by multiple mosquito species with varying VC. However, the extent to which bottlenecks and VC are linked is poorly understood. Similarly, quantitative analyses of mosquito-imposed bottlenecks on virus populations are limited. We used molecularly barcoded WNV to quantify tissue-associated population bottlenecks in three variably competent WNV vectors. Our results confirm strong population bottlenecks during mosquito infection that are capable of dramatically reshaping virus population structure in a non-selective manner. In addition, we found that mosquitoes with differing VC uniquely shape WNV population structure: highly competent vectors are more likely to contribute to the maintenance of rare viral genotypes. These findings have important implications for arbovirus emergence and evolution