Microcosm carl zimmer12/3/2023 ![]() These genes did not evolve through the familiar rise of new mutations in old genes. Way #2: It turns out there are also a lot of genes in the spinach outbreak bacteria that are not found in any E. coli O157:H7’s ability to stick to surfaces, like those of sprouts. It also has mutant genes for cellulose and for hair-like projections from its surface, both of which have proven important to E. coli, from the chemical reactions it uses to break down food to the shape of its membrane. These mutations altered genes that carry out many functions in E. Way #1: New mutations arose spontaneously in individual microbes, were passed down from ancestors to descendants, and then spread through the population by natural selection or a more random process called genetic drift. The new study drives home a remarkable lesson: the bacteria that caused the spinach outbreak was different in many ways from other E. The scientists published their preliminary results last year (about which I wrote a piece for Slate), but now they’ve just published their detailed analysis in the journal Infection and Immunity. That was over three times the average rate in previous outbreaks, and so scientists have taken a closer look at these particular bacteria–this sub-sub-strain, as it were, to figure out what made it so nasty. Over the course of two months, 205 people got sick from tainted spinach, and 15% of them developed the more dangerous form of the infection (called hemolytic uremic syndrome). Then it was spinach that was ferrying the bacteria, not cookie dough or sprouts. ![]() I base that prediction on the last headline-making E. But chances are good that the story is going to be complicated, in a way that’s both disturbing and fascinating. There’s no official word for how the bacteria got from a cow to a cookie (or at least, a cookie in the making). And now the bacteria have turned up in cookie dough. coli O157:H7 infected thousands of school children in Japan. In 1996, for example, radish sprouts contaminated with E. coli O157:H7 have not been caused by tainted beef. That’s why you should always cook hamburgers all the way through–just a few microbes are enough to get you sick. People can get sick from an infected cow if its intestines are nicked during slaughter and the bacteria can contaminate the muscle. The bacteria can survive for months in a barn or a corral, and can then get blown onto grass or other food eaten by another cow. The bacteria can spread from cow to cow by passing out of one host with their droppings. coli O157:H7 suggest that it emerged and spread in parallel with the spread of cattle over the past 1000 years. ![]() In those animals, this strain doesn’t seem to do much harm and may even benefit its host. coli O157:H7 is livestock–especially cows and sheep. It’s a mysterious new move from a mysterious microbe. coli O157:H7 in a batch of Nestle chocolate cookie dough. On rare occasion, however, the bacteria unleash toxins that can spread through the blood stream, killing cells and leading to kidney failure.Īt the end of June the Centers for Disease Control detected E. Typically this manipulation leads to painful, bloody diarrhea but little more. coli O157:H7, can stick to the walls of the intestines and build needles through which it can inject molecules into host cells that can alter them in many ways, so that the cells disgorge food the microbe can eat. coli dwelling inside you right now, quietly grazing on the extra sugar in your gut. coli share the same backbone of certain genes, they can be divvied up into a vast number of strains, each with a distinctive genetic profile. coli ” embraces a veritable empire of bacteria. Or, to be specific, some raw cookie dough carrying a dangerous cargo of toxic E. ![]() There’s no better way to kick off Microcosm Week than with some chocolate chip cookies. coli that may change the way you think about life as a whole. In celebration of the arrival of the paperback Microcosm, I’m going to take a look at some fresh-out-of-the-oven research on E. This is not actually a rhetorical stretch over the past century scientists have put a spectacular amount of work into understanding this bug. coli as a microscopic oracle that can reveal great secrets about how life in general works. ![]() Coli and the New Science of Life will be published. Next week the paperback edition of my book Microcosm: E. ![]()
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