OSIRIS-REx Contamination Control Strategy and Implementation.

OSIRIS-REx will return pristine samples of carbonaceous asteroid Bennu. This article describes how pristine was defined based on expectations of Bennu and on a realistic understanding of what is achievable with a constrained schedule and budget, and how that definition flowed to requirements and implementation. To return a pristine sample, the OSIRIS-REx spacecraft sampling hardware was maintained at level 100 A/2 and <180 ng/cm of amino acids and hydrazine on the sampler head through precision cleaning, control of materials, and vigilance.

Expansion of the Clostridium perfringens toxin-based typing scheme.

Clostridium perfringens causes many different histotoxic and enterotoxic diseases in humans and animals as a result of its ability to produce potent protein toxins, many of which are extracellular. The current scheme for the classification of isolates was finalized in the 1960s and is based on their ability to produce a combination of four typing toxins - α-toxin, β-toxin, ε-toxin and ι-toxin - to divide C. perfringens strains into toxinotypes A to E.

Zoonotic Transfer of Clostridium difficile Harboring Antimicrobial Resistance between Farm Animals and Humans.

The emergence of as a significant human diarrheal pathogen is associated with the production of highly transmissible spores and the acquisition of antimicrobial resistance genes (ARGs) and virulence factors. Unlike the hospital-associated RT027 lineage, the community-associated RT078 lineage is isolated from both humans and farm animals; however, the geographical population structure and transmission networks remain unknown. Here, we applied whole-genome phylogenetic analysis of 248 RT078 strains from 22 countries.