All You Need is Pla (for Pneumonic Plague)

Yersinia pestis. By Mrs Robinson at bg.wikipedia (Transferred from bg.wikipedia) [Public domain], from Wikimedia Commons.
Writing about Yersinia pestis or the Black Death, has earned me a reputation among Promega Connections bloggers. I am interested in what researchers have been able to piece together about the causative agent of ancient plagues, what modern research shows about how Y. pestis spreads in the body and the continuing reservoirs in modern times, resulting in publication of eight blog posts on the subject. Understanding Y. pestis bacterium is of continuing interest to researchers. How did Yersinia pestis evolve from the humble Yersinia pseudotuberculosis, a pathogen that causes gastrointestinal distress, into a virulent pneumonic plague that is a global killer? One strategy for answering this question is to look at the genomic tree of Y. pestis and trace which strains had what characteristics. In a recent Nature Communications article, Zimbler et al. explored the role of the plasmid pPCP1 in Y. pestis evolution and the signature protease Pla it expresses. Continue reading “All You Need is Pla (for Pneumonic Plague)”

Dance Macabre: Will 14th Century Remains Reveal the Pandemic Secrets of the Black Death?

Last year, I reviewed a PLoS Pathogens paper that found European Black Plague victims from the mid 14th century were infected with more than one clone of Yersinia pestis. While the Y. pestis-specific sequences amplified from several skeletal samples from various countries were evidence of the bacterium as the etiological agent, questions still remained about the virulence of the outbreak. What allowed that ancient strain of Y. pestis to cause such widespread death? Another group of researchers decided to further analyze the causative agent of the Black Plague by enriching for and sequencing one of the extrachromasomal plasmids present in the bacterial genome: the 9.6kb virulence-associated pPCP1 plasmid. Continue reading “Dance Macabre: Will 14th Century Remains Reveal the Pandemic Secrets of the Black Death?”

Recycle or Compost? Sorting Out the Cornstarch from the Plastic

Environmental concerns have driven people to seek products that are not derived from petroleum. This has translated into people using products from renewable resources for serving food and beverages. Now you are drinking iced tea out of corn plastic cups or coffee from paper cups labeled as ecofriendly. What does this label mean and what do you do with them when you have consumed your beverage?

Corn plastic is called polylactic acid or PLA. It is derived from corn as well as other starch-rich crops like sugar beets and wheat. The starch is isolated from the source crop, and dextrose (a sugar) is then processed from the starch and fermented to lactic acid. Continue reading “Recycle or Compost? Sorting Out the Cornstarch from the Plastic”