Some 11 percent of the cell culture-based projects housed in the NCBI Sequence Read Archive appear to be contaminated with mycoplasma, Anthony Olarerin-George and John Hogenesch from the University of Pennsylvania report.
Mycoplasma is often introduced accidentally into cell cultures by lab workers, and it cannot be killed by the antibiotics typically used to treat such cultures.
In a paper posted to bioRxiv, the duo recounts how they surveyed RNA-seq data from nearly 9,400 samples housed in the NCBI archives for evidence of mycoplasma sequences by mapping reads from those samples to the four complete mycoplasma genomes — M. hominis, M. hyorhinis, M. fermentans, and A. laidlawii.
The duo further calculated that mycoplasma contamination may cost some $350 million in wasted time and resources. Hogenesch's own lab has faced infections with one bout costing $100,000 and a year's worth of work, Nature News says.
"There's no magic 21st century bullet that's going to kill these things," Hogenesch tells Nature News. "We have to be continuously vigilant, clean up the cultures that have them, and destroy the bacteria altogether."