Accumulating data implicate mycoplasma contamination as the single biggest problem in the culture of continuous cell lines.
Mycoplasma infection can affect virtually every parameter and functional activity of the eukaryotic cells. A successful alternative to discarding infected cultures is to attempt to eliminate the contaminants by treatment with specific and efficient antimycoplasma
antibiotics. The addition of
antibiotics to the culture medium during a limited period of time (1-3 wk) is a simple, inexpensive, and very practical approach for decontaminating continuous cell lines. Here, we examined the effectiveness of several
antibiotic treatment protocols that we have employed routinely in our cell lines bank. On an aggregate, 673 cultures from 236 chronically mycoplasma-positive cell lines were exposed to one of the following five
antibiotic regimens:
mycoplasma removal agent (
quinolone; a 1-wk treatment),
enrofloxacin (
quinolone; 1 wk),
sparfloxacin (
quinolone; 1 wk),
ciprofloxacin (
quinolone; 2 wk), and
BM-Cyclin (alternating
tiamulin and
minocycline; 3 wk). The
mycoplasma infection was permanently (as determined by three solid mycoplasma detection assays) eliminated by the various
antibiotics in 66-85% of the cultures treated. Mycoplasma resistance was seen in 7-21%, and loss of the culture as a result of cytotoxically caused cell death occurred in 3-11% of the cultures treated. Overall, 223 of the 236 mycoplasma-positive cell lines could be cured in a first round of
antibiotic treatment with at least one regimen. Taken together, 95% of the mycoplasma-infected cell lines were permanently cleansed of the contaminants by
antibiotic treatment, which validates this approach as an efficient and technically simple mycoplasma eradication method.