Phase variable colony variants are conserved across spp. and exhibit different virulence-associated phenotypes.

The genus, comprising at least 13 species, is associated with the polymicrobial disorder bacterial vaginosis (BV). However, the details of BV pathogenesis are poorly defined, and the contributions made by individual species, including spp., are largely unknown.

Adaptation of the Mycobacterium tuberculosis transcriptome to biofilm growth.

Mycobacterium tuberculosis (M. tb), the causative agent of tuberculosis (TB), is a leading global cause of death from infectious disease. Biofilms are increasingly recognized as a relevant growth form during M.

Portrait of a generalist bacterium: pathoadaptation, metabolic specialization and extreme environments shape diversity of .

Unlabelled: is a Gram-positive, coagulase-negative staphylococcus found in diverse environments including soil and freshwater, meat, and dairy foods. is also an important cause of urinary tract infections (UTIs) in humans, and mastitis in cattle. However, the genetic determinants of virulence have not yet been identified, and it remains unclear whether there are distinct sub-populations adapted to human and animal hosts.

Adaptation of the transcriptome to biofilm growth.

Unlabelled: ( ), the causative agent of tuberculosis (TB), is a leading global cause of death from infectious disease. Biofilms are increasingly recognized as a relevant growth form during infection and may impede treatment by enabling bacterial drug and immune tolerance. has a complicated regulatory network that has been well-characterized for many relevant disease states, including dormancy and hypoxia.

The Gonococcal Genetic Island defines distinct sub-populations of .

The incidence of gonorrhoea is increasing at an alarming pace, and therapeutic options continue to narrow as a result of worsening drug resistance. is naturally competent, allowing the organism to adapt rapidly to selection pressures including antibiotics. A sub-population of carries the Gonococcal Genetic Island (GGI), which encodes a type IV secretion system (T4SS) that secretes chromosomal DNA.

Need for speed: Key driver of host cell migration varies among mycobacteria.

In this issue of Cell, Saelens et al. describe a new function for mycobacterial Type VII secretion systems: manipulation of host cell migration. They find that a substantial proportion of global TB cases arise from bacteria lacking this function, raising questions about its role in pathoadaptation of Mycobacterium tuberculosis.

Comparative Genomics of Streptococcus oralis Identifies Large Scale Homologous Recombination and a Genetic Variant Associated with Infection.

The viridans group streptococci (VGS) are a large consortium of commensal streptococci that colonize the human body. Many species within this group are opportunistic pathogens causing bacteremia and infective endocarditis (IE), yet little is known about why some strains cause invasive disease. Identification of virulence determinants is complicated by the difficulty of distinguishing between the closely related species of this group.

Rapid adaptation of a complex trait during experimental evolution of .

Tuberculosis (TB), caused by (), is a leading cause of death due to infectious disease. TB is not traditionally associated with biofilms, but biofilms are linked with drug and immune tolerance and there is increasing recognition of their contribution to the recalcitrance of TB infections. Here, we used experimental evolution to investigate this complex phenotype and identify candidate loci controlling biofilm formation.

Evolution of Tuberculosis Pathogenesis.

is a globally distributed, lethal pathogen of humans. The virulence armamentarium of appears to have been developed on a scaffold of antiphagocytic defenses found among diverse, mostly free-living species of . Pathoadaptation was further aided by the modularity, flexibility, and interactivity characterizing mycobacterial effectors and their regulators.

Genome reorganization during emergence of host-associated .

is a rapid growing, free-living species of bacterium that also causes lung infections in humans. Human infections are usually acquired from the environment; however, dominant circulating clones (DCCs) have emerged recently in both subsp. and subsp.

Transcriptional and Translational Responsiveness of the Neisseria gonorrhoeae Type IV Secretion System to Conditions of Host Infections.

The type IV secretion system of Neisseria gonorrhoeae translocates single-stranded DNA into the extracellular space, facilitating horizontal gene transfer and initiating biofilm formation. Expression of this system has been observed to be low under laboratory conditions, and multiple levels of regulation have been identified. We used a translational fusion of to , the gene for the type IV secretion system coupling protein, to screen for increased type IV secretion system expression.

Representing Tuberculosis Transmission with Complex Contagion: An Agent-Based Simulation Modeling Approach.

Objective: A recent study reported a tuberculosis (TB) outbreak in which, among newly infected individuals, exposure to additional active infections was associated with a higher probability of developing active disease. Referred to as , multiple reexposures to TB within a short period after initial infection is hypothesized to confer a greater likelihood of developing active infection in 1 y. The purpose of this article is to develop and validate an agent-based simulation model (ABM) to study the effect of complex contagion on population-level TB transmission dynamics.

Revealing fine-scale spatiotemporal differences in SARS-CoV-2 introduction and spread.

Evidence-based public health approaches that minimize the introduction and spread of new SARS-CoV-2 transmission clusters are urgently needed in the United States and other countries struggling with expanding epidemics. Here we analyze 247 full-genome SARS-CoV-2 sequences from two nearby communities in Wisconsin, USA, and find surprisingly distinct patterns of viral spread. Dane County had the 12 known introduction of SARS-CoV-2 in the United States, but this did not lead to descendant community spread.

Distinct patterns of SARS-CoV-2 transmission in two nearby communities in Wisconsin, USA.

Evidence-based public health approaches that minimize the introduction and spread of new SARS-CoV-2 transmission clusters are urgently needed in the United States and other countries struggling with expanding epidemics. Here we analyze 247 full-genome SARS-CoV-2 sequences from two nearby communities in Wisconsin, USA, and find surprisingly distinct patterns of viral spread. Dane County had the 12th known introduction of SARS-CoV-2 in the United States, but this did not lead to descendant community spread.

Lateral Gene Transfer Shapes Diversity of spp.

spp. are pathognomonic for bacterial vaginosis, which increases the risk of preterm birth and the transmission of sexually transmitted infections. spp.

Dispersal of Driven by Historical European Trade in the South Pacific.

() is a globally distributed bacterial pathogen whose population structure has largely been shaped by the activities of its obligate human host. Oceania was the last major global region to be reached by Europeans and is the last region for which the dispersal and evolution of remains largely unexplored. Here, we investigated the evolutionary history of the Euro-American L4.

Genetic susceptibility to severe childhood asthma and rhinovirus-C maintained by balancing selection in humans for 150 000 years.

Selective pressures imposed by pathogens have varied among human populations throughout their evolution, leading to marked inter-population differences at some genes mediating susceptibility to infectious and immune-related diseases. Here, we investigated the evolutionary history of a common polymorphism resulting in a Y529 versus C529 change in the cadherin related family member 3 (CDHR3) receptor which underlies variable susceptibility to rhinovirus-C infection and is associated with severe childhood asthma. The protective variant is the derived allele and is found at high frequency worldwide (69-95%).

Effects of Host, Sample, and Culture on Genomic Diversity of Pathogenic Mycobacteria.

(), an obligate human pathogen and the etiological agent of tuberculosis (TB), remains a major threat to global public health. Comparative genomics has been invaluable for monitoring the emergence and spread of TB and for gaining insight into adaptation of . Most genomic studies of are based on single bacterial isolates that have been cultured for several weeks .

Investigation of Genetic Susceptibility to Blastomycosis Reveals Interleukin-6 as a Potential Susceptibility Locus.

Genetic differences are hypothesized to underlie ethnic disparities in incidence rates of the endemic systemic mycoses, including blastomycosis. Individuals of Hmong ancestry display elevated risk for this serious fungal infection. Here, we interrogated the genomes of Wisconsin (WI) Hmong blastomycosis patients using homozygosity mapping to uncover regions of the genome that are likely shared among the greater Hmong population and filtered for variants with high potential to affect disease susceptibility.

Lineage specific histories of Mycobacterium tuberculosis dispersal in Africa and Eurasia.

Mycobacterium tuberculosis (M.tb) is a globally distributed, obligate pathogen of humans that can be divided into seven clearly defined lineages. An emerging consensus places the origin and global dispersal of M.

Multiple exposures, reinfection and risk of progression to active tuberculosis.

A recent study reported on a tuberculosis (TB) outbreak in a largely Inuit village. Among newly infected individuals, exposure to additional active cases was associated with an increasing probability of developing active disease within a year. Using binomial risk models, we evaluated two potential mechanisms by which multiple infections during the first year following initial infection could account for increasing disease risk with increasing exposures.