Articles tagged Bacteria
(9 results)

Bacteria becoming antibiotic-resistant, insects becoming pesticide-resistant, and organisms adapting to hostile environments are all examples of adaptive evolution through natural selection. Each adaptive event leaves its mark in the organism’s DNA; beneficial alleles become fixed and can be detected in the majority of the population. By understanding this process, population geneticists and evolutionary biologists figure…

Guest authors C. Brandon Ogbunugafor and Rafael F. Guerrero demystify higher order epistasis through a short story about the perfect brew. Epistasis is the flavor of the month Epistasis is one of the most popular and provocative topics in modern genetics. It has many different definitions, but one especially useful one is that epistasis is…

Improved duplex sequencing identifies spontaneous mutations in bacteria without long-term culturing. Spontaneous mutations are the driving force of evolution, yet, our ability to detect and study them can be limited to mutations that accumulate clonally. Sequencing technology often cannot identify very rare variants or discriminate between bona fide mutations and errors introduced during sample preparation.…

A strain of Staphylococcus epidermidis isolated from a hotel room may provide insight into how resistance develops outside of medical settings. Although intense research and media interest has focused on drug-resistant bacteria in hospital settings, resistance can and does evolve outside the clinic. Methicillin-resistant Staphylococcus epidermidis is often isolated from infections of medical devices, but…

Guest post by Nina Wolff pays tribute to long-standing GSA member Margaret Lieb. Margaret (Peggy) Lieb died on March 8, 2018 in South Pasadena, California at the age of 94. After attending schools in New Rochelle, NY, she graduated magna cum laude from Smith College, and subsequently studied with  H.J. Muller at Indiana University and…

In the ruins of the Chernobyl Nuclear Power Plant—an area deemed unsafe for humans for the next 20,000 years after a catastrophic failure—life thrives. Fungi that reside there, along with other organisms that can survive large radiation doses, must have strategies to cope with the DNA-damaging effects of living at a meltdown site. In the…

Lurking in colonies of pathogenic bacteria are drug-resistant mutants. If the colony is exposed to antibiotics, these resistant mutants may survive, but they still face the challenge of recolonizing the host. Their success in this task depends on their diversity; a diverse population is more likely to harbor mutants that can withstand a second threat,…

Antibiotics, a vital tool for fighting infections, were originally products of nature—the first antibiotic was serendipitously discovered in mold contaminating a bacterial culture. As antibiotic resistance becomes an increasingly serious threat, scientists are attempting to wring another type of pathogen-fighting drug from the wild: antimicrobial peptides. Antimicrobial peptides, or AMPs, are found in almost every…

In the early 1940s, many biologists doubted bacteria had genes. After all, they seemed to play by their own genetic rules: they appeared to lack chromosomes, meiosis, mitosis, sex, and all the other trappings of Mendelian inheritance. They even seemed to show a kind of Lamarckian inheritance, in which an individual could pass on traits acquired…