Small Things Considered

Three to Tango

by Elio | How many symbioses that involve three partners can you think of? Surely, not many. But here is one, involving a pathogenic fungus, a bacterium, and a fungal virus. Read more →

Of Terms in Biology: Contagion

by Elio | A much used term nowadays, "con­ta­gi­on" or in ad­jec­tive form, "con­ta­gi­ous," is de­rived from La­tin con­tā­giō (touch­ing, con­tact, con­ta­gi­on) re­la­ted to con­tin­gō (touch clo­se­ly). In its ori­gi­nal mean­ing, the term re­fer­red so­le­ly to a dis­ease trans­mis­sible by di­rect phy­si­cal con­tact. Now­adays, its mean­ing has been broad­ened to in­clude all com­mu­ni­cable or in­fect­ious dis­ea­ses. As the Wi­ki­pe­dia says: "Of­ten the word... Read more →

Where Do Phages of Atypical Bacteria Come From? A Snippet.

by Elio | Some time ago, a piece in this blog dealt with the com­ple­xi­ties of the Gram stain. In brief, it said: "In a simp­ler world, all bac­te­ria with a single mem­brane, the mono­derms, would be Gram-po­si­tive, all those with two (the di­derms), Gram-ne­ga­tive... Hah! Were it that simple! Each of these groups... Read more →

Flagella By the Tail

by Elio | We now know that the site of delivery of the phage DNA is not the flagellar filament but rather a region near its base. When the phage reaches it, it can deliver its DNA into the host, as demonstrated by the presence of empty (DNA-less) phage heads at the base of the flagellum. The whole thing takes less than 5 minutes. Read more →

Will the real phage lambda please stand up?

by Nicholas Redmond | Phage infection of a bacterial cell typically begins when the phage’s tail fibers bind a receptor on the host cell, allowing for the ejection of genetic material. At this point, either the lytic or lysogenic cycle begins. Read more →

Secondary Metabolites

by Andy Bodnar, Michelle Prieto, and Carleen Villarreal | The war between bac­te­ria and pha­ges has been wa­ging for eons lon­ger than hu­mans have ex­ist­ed. Con­sequent­ly, ma­ny bacte­ria have de­ve­loped no­vel and unique ways for de­fen­ding them­selves against these fo­reign in­va­ders. Some change their sur­face pro­teins to pre­vent de­tec­tion, like chang­ing a lock on a door. Others give their own lives, ini­tia­ting... Read more →

Distributed virusing?

by Jamie | Viruses are very creative genetic entities. Their supersonic mutation rates (compared to ours) have allowed them to explore a wide range of possibilities in genome structure. Thus, while all cellular life has double-stranded DNA genomes, with options limited to circular or linear chromosomes, viruses are represented by just about every type of genome imaginable. Read more →

Phage Therapy – an Update

by Elio | Has there ever been a more perplexing topic in microbiology than phage therapy? Well, that of probiotics comes close. Both have an over 100-year history, both have proponents as well as detractors, both have seen major investments in research and commercialization. Read more →

Fungi, Toxins, and Fungal Viruses (A Snippet)

by Elio | Fungi make toxins (called, not surprisingly, mycotoxins). This won’t surprise you because you know that certain mushrooms are poisonous and you may know of the aflatoxins, noxious chemicals made by molds that grow on stored grains. Read more →

Phage Phactories

by Merry | it’s not news to STC readers that phages encode cytoskeletal proteins. Daniel Haeusser’s fine post related this story as it was known in 2012. Two key papers published that year investigated the tubulin homologs found in phage genomes. At that time, phage-encoded tubu­lin homologs fell into two phylogenetic clusters... Read more →