Bloom

Wil McCarthy dares to combine two branches of scientific study--space-travel technology and biotechnology--to create a chilling and very believable future as Bloom pits humankind against an enemy of its own creation, grown rampantly out of control.

In the late twenty-first century, man-made, self-replicating organisms called mycora--smaller than the tiniest bacteria--mutated and swept across the globe in a chain reaction so swift and deadly there was no time to act. No time to do anything but flee an Earth destroyed by the very science created to nurture and sustain it. Soon the entire inner solar system was consumed, incorporated into the lethal psychedelic bloom of the Mycosystem.

Scant years later, the remnants of humanity cling to the asteroid belt and the inhospitable moons of Jupiter. As the society known as the Immunity ekes out a precarious existence, fighting off the invasion of deadly mycospores while working feverishly to build a starship that will carry them to safety, an ominous discovery alters everything. Mycora are incorporating gene sequences to elude Immunity defenses--perhaps even to thrive in the harsh environment of the outer system.

Synopsis from Open Library.