In vivo efficacy of the boron-pleuromutilin AN11251 against Wolbachia of the rodent filarial nematode Litomosoides sigmodontis

The elimination of filarial diseases such as onchocerciasis and lymphatic filariasis is hampered by the lack of a macrofilaricidal – adult worm killing – drug. In the present study, we tested the in vivo efficacy of AN11251, a boron-pleuromutilin that targets endosymbiotic Wolbachia bacteria from filarial nematodes and compared its efficacy to doxycycline and rifampicin. Doxycycline and rifampicin that were previously shown to deplete Wolbachia endosymbionts leading to a permanent sterilization of the female adult filariae and adult worm death in human clinical studies. Twice-daily oral treatment of Litomosoides sigmodontis-infected mice with 200 mg/kg AN11251 for 10 days achieved a Wolbachia depletion > 99.9% in the adult worms, exceeding the Wolbachia reduction by 10-day treatments with bioequivalent human doses of doxycycline and a similar reduction as high-dose rifampicin (35 mg/kg). Wolbachia reductions of > 99% were also accomplished by 14 days of oral AN11251 at a lower twice-daily dose (50 mg/kg) or once-per-day 200 mg/kg AN11251 treatments. The combinations tested of AN11251 with doxycycline had no clear beneficial impact on Wolbachia depletion, achieving a > 97% Wolbachia reduction with 7 days of treatment. These results indicate that AN11251 is superior to doxycycline and comparable to high-dose rifampicin in the L. sigmodontis mouse model, allowing treatment regimens as short as 10-14 days. Therefore, AN11251 is represents a promising pre-clinical candidate that was identified in the L. sigmodontis model, and could be further evaluated and developed as potential clinical candidate for human lymphatic filariasis and onchocerciasis.  AUTHOR SUMMARY Onchocerciasis and lymphatic filariasis are human filarial tropical diseases, which can cause blindness and severe dermatitis (onchocerciasis) or lymphedema and hydrocele (lymphatic filariasis). Current strategies to eliminate these diseases include the mass drug administration (MDA) of drugs that target the progeny of the filariae, the microfilariae, and temporarily inhibit filarial embryogenesis and, therefore, the transmission of the disease. However, MDA has several limitations that delay the goal of elimination including the lack of a drug with a short term regimen and a potent macrofilaricidal effect. As an alternative approach, the antibiotic doxycycline has been proven to be effective in depleting Wolbachia endosymbionts from adult filariae, which then leads to permanent sterilization and death of the adult worms. Due to contraindications for doxycycline and prolonged treatment regimen of at least 4 weeks, there is an urgent need for new anti-filarial drugs with an improved safety profile and shorter regimens. The current study demonstrates that the boron-pleuromutilin derivative AN11251 provides an excellent in vivo anti-Wolbachia depletion in the Litomosoides sigmodontis filarial mouse model that is superior to doxycycline and comparable to rifampicin, allowing for regimens as short as 10-14 days. Combination with doxycycline for 7 days had no significant beneficial effect on efficacy, achieving Wolbachia reductions of more than 97%. Therefore, AN11251 shows potent anti-Wolbachia activity in the L. sigmodontis mouse model and may also present an alternative pre-clinical candidate for filariasis treatment

A Geospatial Modelling Approach Integrating Archaeobotany and Genetics to Trace the Origin and Dispersal of Domesticated Plants

Background: The study of the prehistoric origins and dispersal routes of domesticated plants is often based on the analysis of either archaeobotanical or genetic data. As more data become available, spatially explicit models of crop dispersal can be used to combine different types of evidence. Methodology/Principal Findings: We present a model in which a crop disperses through a landscape that is represented by a conductance matrix. From this matrix, we derive least-cost distances from the geographical origin of the crop and use these to predict the age of archaeological crop remains and the heterozygosity of crop populations. We use measures of the overlap and divergence of dispersal trajectories to predict genetic similarity between crop populations. The conductance matrix is constructed from environmental variables using a number of parameters. Model parameters are determined with multiple-criteria optimization, simultaneously fitting the archaeobotanical and genetic data. The consilience reached by the model is the extent to which it converges around solutions optimal for both archaeobotanical and genetic data. We apply the modelling approach to the dispersal of maize in the Americas. Conclusions/Significance: The approach makes possible the integrative inference of crop dispersal processes, whil