We have been using 10 mg/L of chloroamphenicol to treat a gluconobacter
infection of our cultures (which also produced a mucoid slime surface
that "drowned" the flies), which we had found to be the most effective
antibiotic. This seems to have reduced (but not eliminated) the
problem, possibly because the bacteria may have developed some resistance.
However, I suspect that your research infection will be just as
susceptible to chloroamphenicol as to tetracycline.