Wolbachiaand the antifilarial properties of tetracycline. An untold story

Abstract

The idea that tetracycline may have antifilarial properties was first proposed in 1960. Data were subsequently published on the effects of tetracycline on the development and reproduction of Brugia pahangi in both the mosquito and mammalian hosts. These studies were apparently ignored until recently. In 1998, it was suggested that the antifilarial properties of tetracycline may derive from the presence of the bacterial endosymbiont Wolbachia in filarial worms. In view of this renewed interest, we would like to highlight an old study on the prophylactic activity of tetracycline against three filarial species. Although this work was performed at the begining of the seventies, and presented at a congress in 1973, it has never been published. This study showed that tetracycline had a prophylactic effect against infection of the mammalian host (the gerbil Meriones unguiculatus) with B. pahangi and Litomosoides sigmodontis. On the other hand, no significant prophylactic effect of the drug was observed against Acanthocheilonema viteae in the same host. The new data on the distribution and phylogeny of Wolbachia endosymbionts in filarial nematodes, showing that A. viteae is uninfected and that B. pahangi and L. sigmodontis are infected, suggest that the activity of tetracycline on the latter two species is related to the presence of Wolbachia.

Mapping the presence of Wolbachia pipientis on the phylogeny of filarial nematodes: evidence for symbiont loss during evolution

“…In this way, L. yutajensis could become a valid alternative to the use of A. viteae (which is negative for W. pipientis) as a sort of 'negative control' (e.g. see Hoerauf et al, 1999;McCall et al, 1999;Taylor et al, 2000 andSaint André et al, 2002), being more closely related to a filarial model which harbors W. pipientis (L. sigmodontis) than A. viteae (see Casiraghi et al, 2001b). Litomosoides species are thought to have evolved as parasites of bats in South America, and diversified in rodents only recently (about 3 millions years), when these migrated from North America during the Pliocene-Pleistocene; their passage into small marsupials is also believed to have occurred after the Pliocene-Pleistocene Philipp, 1991 andGuerrero et al, 2002).…”

“…In arthropods W. pipientis generally induces alterations in host reproduction (Werren, 1997;Stouthamer et al, 1999 andBandi et al, 2001). In filarial nematodes there is convincing evidence that these bacteria are required for the development and reproduction of their hosts Bandi et al, 1999;Hoerauf et al, 1999;McCall et al, 1999;Hoerauf et al, 2000 andCasiraghi et al, 2002).…”

Relationship between Psoroptes cuniculi and the Internal Bacterium Serratia marcescens

“…Various biological means of mange mite control are being explored including the use of entomopathogenic fungi Brooks and Wall 2001). In this context, the study of the internal bacterial flora of Psoroptes mites could also give useful information, because some recent studies on bacterial endo-symbionts of other mammalian parasites, such as those of filarial nematodes, have shown that bacteria of the genus Wolbachia are necessary for normal embryogenesis and are transmitted transovarially; this has led to the possibility of the use of tetracycline for the control of these parasites (Bosshardt et al 1993;Bandi et al 1999;McCall et al 1999).…”

Molecular identification of Wolbachia from the filarial nematode Mansonella ozzardi

“…This phylogenetic pattern suggests that ®larial nematodes and their Wolbachia share a long co-evolutionary history which should have led to reciprocal co-adaptation and dependence . Indeed, tetracycline treatments targeted towards Wolbachia are detrimental to those ®larial hosts harbouring Wolbachia (Bosshardt et al 1993;Genchi et al 1998;Hoerauf et al 1999;McCall et al 1999;Langworthy et al 2000). Intracellular bacteria have been observed, but not yet identi®ed, in the ®larial nematode Mansonella ozzardi (Kozek and Raccurt 1983), a parasite of the body cavity of humans in Latin America, from northern Argentina to the Yucatan peninsula and the West Indies.…”