Genomic insights into the evolution of secondary metabolism of and its allies, specialized fungal symbionts of fungus-farming ants.

The metabolic intimacy of symbiosis often demands the work of specialists. Natural products and defensive secondary metabolites can drive specificity by ensuring infection and propagation across host generations. But in contrast to bacteria, little is known about the diversity and distribution of natural product biosynthetic pathways among fungi and how they evolve to facilitate symbiosis and adaptation to their host environment.

Development of an Amplicon Nanopore Sequencing Strategy for Detection of Mutations Conferring Intermediate Resistance to Vancomycin in Staphylococcus aureus Strains.

Staphylococcus aureus is a major cause of bacteremia and other hospital-acquired infections. The cell-wall active antibiotic vancomycin is commonly used to treat both methicillin-resistant (MRSA) and sensitive (MSSA) infections. Vancomycin intermediate S.

Species-Scale Genomic Analysis of Staphylococcus aureus Genes Influencing Phage Host Range and Their Relationships to Virulence and Antibiotic Resistance Genes.

Phage therapy has been proposed as a possible alternative treatment for infections caused by the ubiquitous bacterial pathogen Staphylococcus aureus. However, successful therapy requires understanding the genetic basis of host range-the subset of strains in a species that could be killed by a particular phage. We searched diverse sets of S.

Symbiont Genomic Features and Localization in the Bean Beetle .

A pervasive pest of stored leguminous products, the bean beetle Callosobruchus maculatus (Coleoptera: Chrysomelidae) associates with a simple bacterial community during adulthood. Despite its economic importance, little is known about the compositional stability, heritability, localization, and metabolic potential of the bacterial symbionts of C. maculatus.

Genes Influencing Phage Host Range in Staphylococcus aureus on a Species-Wide Scale.

is a human pathogen that causes serious diseases, ranging from skin infections to septic shock. Bacteriophages (phages) are both natural killers of , offering therapeutic possibilities, and important vectors of horizontal gene transfer (HGT) in the species. Here, we used high-throughput approaches to understand the genetic basis of strain-to-strain variation in sensitivity to phages, which defines the host range.

Gas gangrene-associated gliding motility is regulated by the Clostridium perfringens CpAL/VirSR system.

Clostridium perfringens strains cause a wide variety of human and animal disease, including gas gangrene or myonecrosis. Production of toxins required for myonecrosis, PFO and CPA, is regulated by the C. perfringens Agr-like (CpAL) system via the VirSR two-component system.

Interaction between Streptococcus pneumoniae and Staphylococcus aureus Generates OH Radicals That Rapidly Kill Staphylococcus aureus Strains.

rapidly kills by producing membrane-permeable hydrogen peroxide (HO). The mechanism by which -produced HO mediates killing was investigated. An model that mimicked - contact during colonization of the nasopharynx demonstrated that killing required outcompeting densities of Compared to the wild-type strain, isogenic Δ and Δ, both deficient in production of HO, required increased density to kill While residual HO activity produced by single mutants was sufficient to eradicate , an Δ Δ double mutant was unable to kill A collection of 20 diverse methicillin-resistant (MRSA) and methicillin-susceptible (MSSA) strains showed linear sensitivity ( = 0.

Determinants of Phage Host Range in Species.

Bacteria in the genus are important targets for phage therapy due to their prevalence as pathogens and increasing antibiotic resistance. Here we review outer surface features and specific phage resistance mechanisms that define the host range, the set of strains that an individual phage can potentially infect. Phage infection goes through five distinct phases: attachment, uptake, biosynthesis, assembly, and lysis.

Whole-Genome Sequences of Staphylococcus aureus Isolates from Cystic Fibrosis Lung Infections.

Staphylococcus aureus is an early colonizer in the lungs of individuals with cystic fibrosis (CF), but surprisingly, only a limited number of genomes from CF-associated S. aureus isolates have been sequenced. Here, we present the whole-genome sequences of 65 S.

MetaCRAST: reference-guided extraction of CRISPR spacers from unassembled metagenomes.

Clustered regularly interspaced short palindromic repeat (CRISPR) systems are the adaptive immune systems of bacteria and archaea against viral infection. While CRISPRs have been exploited as a tool for genetic engineering, their spacer sequences can also provide valuable insights into microbial ecology by linking environmental viruses to their microbial hosts. Despite this importance, metagenomic CRISPR detection remains a major challenge.

Determining virus-host interactions and glycerol metabolism profiles in geographically diverse solar salterns with metagenomics.

Solar salterns are excellent model ecosystems for studying virus-microbial interactions because of their low microbial diversity, environmental stability, and high viral density. By using the power of CRISPR spacers to link viruses to their prokaryotic hosts, we explored virus-host interactions in geographically diverse salterns. Using taxonomic profiling, we identified hosts such as archaeal , , and and bacterial , and we found that community composition related to not only salinity but also local environmental dynamics.

Biochemical characterization and zinc binding group (ZBGs) inhibition studies on the catalytic domain of MMP7 (cdMMP7).

Matrix metalloproteinase 7 (MMP7/matrilysin-1) has been implicated in many pathological conditions, such as in cancer and inflammatory diseases; therefore, MMP7 has been targeted for drugs. Success in developing a clinical inhibitor, which exhibits suitable specificity and selectivity, will likely require structural and/or kinetic evaluation of enzyme/inhibitor interactions. To enable these future studies we herein describe the over-expression, purification, and characterization of the catalytic domain of MMP7 (cdMMP7).

Investigating the position of the hairpin loop in New Delhi metallo-β-lactamase, NDM-1, during catalysis and inhibitor binding.

In an effort to examine the relative position of a hairpin loop in New Delhi metallo-β-lactamase, NDM-1, during catalysis, rapid freeze quench double electron electron resonance (RFQ-DEER) spectroscopy was used. A doubly-labeled mutant of NDM-1, which had one spin label on the invariant loop at position 69 and another label at position 235, was prepared and characterized. The reaction of the doubly spin labeled mutant with chromacef was freeze quenched at 500μs and 10ms.

Biochemical, mechanistic, and spectroscopic characterization of metallo-β-lactamase VIM-2.

This study examines metal binding to metallo-β-lactamase VIM-2, demonstrating the first successful preparation of a Co(II)-substituted VIM-2 analogue. Spectroscopic studies of the half- and fully metal loaded enzymes show that both Zn(II) and Co(II) bind cooperatively, where the major species present, regardless of stoichiometry, are apo- and di-Zn (or di-Co) enzymes. We determined the di-Zn VIM-2 structure to a resolution of 1.

Structural and kinetic studies on metallo-β-lactamase IMP-1.

In an effort to probe for metal binding to metallo-β-lactamase (MβL) IMP-1, the enzyme was overexpressed, purified, and characterized. The resulting enzyme was shown to bind 2 equiv of Zn(II), exhibit significant catalytic activity, and yield EXAFS results similar to crystallographic data previously reported. Rapid kinetic studies showed that IMP-1 does not stabilize a nitrocefin-derived reaction intermediate; rather, the enzyme follows a simple Michaelis mechanism to hydrolyze nitrocefin.