Olavi Kajander didn’t mean to discover the mysterious particles that have been called the most primitive organisms on Earth and that could be responsible for a series of painful and sometimes fatal illnesses.

He was simply trying to find out why certain cultures of mammalian cells in his lab would die no matter how carefully he prepared them.

So the Finnish biochemist and his colleagues slipped some of their old cultures under an electron microscope one day in 1988 and took a closer look. That’s when they saw the particles. Like bacteria but an astonishing 100 times smaller, they seemed to be thriving inside the dying cells.

Believing them to be a possible new form of life, Kajander named the particles “nanobacteria,” published a paper outlining his findings and spurred one of the biggest controversies in modern microbiology.

At the heart of the debate is the question of whether nanobacteria could actually be a new form of life. To this day, critics argue that a particle just 20 to 200 nanometers in diameter can’t possibly harbor the components necessary to sustain life. The particles are also incredibly resistant to heat and other methods that would normally kill bacteria, which makes some scientists wonder if they might be an unusual form of crystal rather than organisms.

In 1998, Kajander tried to prove the skeptics wrong by turning up what he believed to be an example of nanobacteria’s ribosomal RNA, something that only organisms have. But the claim was squashed two years later by a National Institutes of Health study, which found that the RNA was actually a remnant from a bacteria that often contaminates lab equipment.

The debate would have ended there, except for a steadily increasing number of studies linking nanobacteria to serious health problems, including kidney stones, aneurysms and ovarian cancer. The studies show that nanobacteria can infect humans, a find that has helped push nanobacteria back into the limelight. Now the pressure is on to resolve the controversy and expose how nanobacteria works — no matter what it is.

“It’s all pretty exciting stuff,” said David McKay, chief scientist for astrobiology at NASA’s Johnson Space Center. “Whether these are bacteria or not — it doesn’t matter at this point. What matters is if we can figure out the association between nanobacteria and kidney stones and develop some kind of countermeasure.”

The link between nanobacteria and human diseases was first noticed by Kajander and microbiologist Neva Çiftçioglu in 1998. The researchers had observed, through an electron microscope, nanobacteria particles building shells of calcium phosphate around themselves. They began to investigate whether such particles played a role in causing kidney stones, which are also made of calcium compounds. Sure enough, at the center of several stones was a nanobacteria particle.

Another breakthrough came in 2003 when a team from the University of Vienna Medical Center discovered nanobacteria in the calcified debris found in tissue samples from ovarian cancer patients. Meanwhile, several other studies revealed nanobacteria in samples of calcified arteries.

More here.