Targeting of Wolbachia endobacteria in Litomosoides sigmodontis: comparison of tetracyclines with chloramphenicol, macrolides and ciprofloxacin

Endobacteria of the genus Wolbachia in filarial nematodes are related to Ri ckettsiaceae and can be depleted by tetracycline antibiotics. This depletio n blocks female worm development as well as early embryogenesis, in contras t to the currently used microfilaricidal ivermectin which blocks only the l ast stage of embryogenesis. Since targeting Wolbachia is becoming an area o f research for the treatment of human filariases, it was investigated if an tibiotics other than tetracyclines are able to deplete Wolbachia from filar iae. BALB/c mice infected with the rodent filaria Litomosoides sigmodontis were treated with erythromycin, chloramphenicol or ciprofloxacin. All drugs were well resorbed and resulted in serum levels clearly above breakpoint l evels for bacteria susceptible to the respective antibiotic. However, contr ary to tetracycline, none of these antibiotics depleted Wolbachia or altere d worm development and fertility, as evidenced by immunohistology, immunoel ectron microscopy and semiquantitative PCR.