Onchocerca parasites and Wolbachia endosymbionts: evaluation of a spectrum of antibiotic types for activity against Onchocerca gutturosa in vitro

Table 1 Summary of long-term trial 1: parasite mean motility scores and viability (MTT colorimetry)

Compound/drug and conc.	Mean motility scores over a period of 40 days									Motility	MTT
DAY	1	5	10	15	20	25	30	35	40	% reduction on day 40 (P)	% inhibition on day 40 (P)
Control	8.0	7.4	7.1	7.0	5.3	5.5	6.3	6.4	4.9
CGP 6140 1.25 × 10^-5M (positive control)	0.5	0.8	0.0	0.5	0.0	0.0	0.0	0.0	0.0	100.0 (0.005)	83.3 (0.098)
Rifampicin 5 × 10^-5M	7.7	6.8	6.7	6.8	3.2	1.7	0.2	0.2	0.0	100.0 (0.002)	89.6 (0.033)
Rifampicin 1.25 × 10^-5M	7.0	7.0	7.3	5.7	6.5	5.2	5.7	5.0	5.6	0.0 (0.647)	0.0 (0.798)
Minocycline 5 × 10^-5M	8.0	6.7	7.3	5.7	0.0	0.0	0.0	0.0	0.0	100.0 (0.002)	84.1 (0.042)
Minocycline 1.25 × 10^-5M	7.8	7.5	6.7	5.7	4.3	2.5	4.8	1.7	0.0	100.0 (0.002)	93.7 (0.026)
Doxycycline 5 × 10^-5M	8.3	8.0	8.0	5.7	0.3	0.0	0.0	0.0	0.0	100.0 (0.002)	93.0 (0.027)
Doxycycline 1.25 × 10^-5M	7.3	6.5	6.3	4.8	6.3	6.3	6.2	6.2	5.5	0.0 (0.699)	0.0 (0.801)
Ethambutol 5 × 10^-5M	6.8	6.8	6.5	6.7	4.0	4.8	4.3	5.0	2.7	44.9 (0.170)	73.0 (0.108)
Dapsone 5 × 10^-5M	7.3	7.3	7.7	5.0	6.8	7.0	7.2	7.3	6.5	0.0 (0.250)	0.0 (0.798)
Pyrazinamide 5 × 10^-5M	7.7	7.7	7.2	3.5	5.5	5.5	5.7	5.2	3.7	24.5 (0.503)	4.8 (0.949)

The effects of exposure to a range of antibiotics on the viability of Onchocerca gutturosa adult males in long-term (40 day) in vitro culture. Viability was assessed by measuring worm motility scores throughout the trial and by MTT colorimetry on day 40.