Evaluation of AnaeroPack(AnP) Type as Tools of Plasmodium falciparum cultivation and Drug Sensitivity Tests.

The AnaeroPack (AnP) system (Mitsui Gas Co., Japan) was produced for the purpose of culturing anaerobic bacteria. The idea using AnP Campylo® for cultivation of Plasmodium falciparum and its successful results were firstly reported by Haruki et al. (1997). In the present study, characterisation of 3 products of AnPs, i.e., AnP CO2® (at a gas phase of 5% CO2 and 15% O2), AnP Campylo® (10% CO2 and 10% O2) and AnP Plas® (5% CO2 and 5% O2), in an AnaeroPack Box Jar® (22×16×10.5 cm) was studied comparing with conditions in a gas incubator or gas chamber (4% CO2 and 3% O2) and in a candle jar (5% CO2 and 15% O2). The growth curves of malaria parasites showed no difference among these four conditions by incubation for 48 hr except for AnP Plas. The observed IC50 levels of chloroquine were varied much by the difference of AnPs, gas phases, the pressure in a Box Jar and free space inside. For stabilisation of IC50 testing, free space in a Box Jar should be kept equal and minimal by placing the maximal 5 test plates by adding dummy plates. By the stable results of IC50, gas phases can be divided into two groups. The one involves the gas incubator, AnP Plas® and AnP Campylo®, and the other does the candle jar and AnP CO2®. Results of chloroquine sensitivity test in the candle jar group showed more drug sensitive than in the gas incubator group. These two groups should be used properly by the purpose of field experiments. The AnP® system is proven to be a practical tool for malaria culture in the field for occupying only a small space in an incubator.