Repeated evolution in sticklebacks, and adjacent possibles

“Researchers have documented repeated evolution in other organisms, but the sticklebacks are unique because the freshwater transition has occurred so many times. “Sticklebacks have been a phenomenal system for understanding rapid evolution,” says evolutionary biologist Erica Bree Rosenblum of the University of California, Berkeley, who wasn’t involved in the study. “This paper shows that repeated […]

The wacky world of horizontal gene transfer, genomic variants, and what we think are microbial species

“The main difference from eukaryotes is that prokaryotic reproduction is independent of DNA acquisition and recombination. Instead, DNA is obtained from fragmented chromosomes obtained via parasexual means (that is, without reproduction). These mechanisms of DNA exchange are not restricted to gene exchange within species, and therefore traits can and do come from highly divergent organisms. […]

The Impact of a Consortium of Fermented Milk Strains on the Gut Microbiome of Gnotobiotic Mice and Monozygotic Twins

“The results also showed that (i) consumption of an FMP containing five bacterial strains was not associated with a statistically significant change in the proportional representation of resident community members within and between individuals; (ii) the appearance and disappearance of strains comprising the FMP consortium did not exhibit familial patterns in the fecal microbiota; and […]

Genome Sequence of E. coli O104:H4 Leads to Rapid Development of a Targeted Antimicrobial Agent against This Emerging Pathogen – PLoS ONE

“A recent widespread outbreak of Escherichia coli O104:H4 in Germany demonstrates the dynamic nature of emerging and re-emerging food-borne pathogens, particularly STECs and related pathogenic E. coli. Rapid genome sequencing and public availability of these data from the German outbreak strain allowed us to identify an O-antigen-specific bacteriophage tail spike protein encoded in the genome. […]

Bacterial genomics: A new source of antimicrobial targets : Nature Reviews Microbiology

“Bacterial clone-based genome sequencing frequently results in gaps, which harbour hypothetical genes of unknown function. Sorek and colleagues show that these gaps contain a vast array of genes encoding proteins that are toxic to the sequencing host (Escherichia coli), including previously uncharacterized restriction enzymes, toxin–antitoxin systems and non-coding RNAs.” Of course, to me, this is […]

Macro and Micro Diversity of Clostridium difficile Isolates from Diverse Sources and Geographical Locations – PLoS ONE

“Clostridium difficile has emerged rapidly as the leading cause of antibiotic-associated diarrheal disease, with the temporal and geographical appearance of dominant PCR ribotypes. We have undertaken a breadth genotyping study using multilocus sequence typing (MLST) analysis of 385 C. difficile strains from diverse sources by host (human, animal and food), geographical locations (North America, Europe […]

Patterns of Gene Flow Define Species of Thermophilic Archaea: PLoS Biology

“Patterns of homologous gene flow among genomes of 12 strains from a single hot spring in Kamchatka, Russia, demonstrate higher levels of gene flow within than between two persistent, coexisting groups, demonstrating that these microorganisms fit the biological species concept. Furthermore, rates of gene flow between two species are decreasing over time in a manner […]

PLoS Biology: How Bacteria Turn Fiber into Food

“Now, a new study by Eric Martens, David Bolam, and colleagues has looked into how a pair of the most common species of gut bacteria metabolize polysaccharides, showing that each bacterium is highly specialized. Using a high-throughput system for feeding the bacteria dozens of kinds of carbohydrates, one at a time, and tracking the bacteria’s […]