Multilocus sequence analysis (MLSA) of ‘Rickettsiella costelytrae' and ‘Rickettsiella pyronotae’, intracellular bacterial entomopathogens from New Zealand
Article first published online: 24 AUG 2012
© 2012 The Authors Journal of Applied Microbiology © 2012 The Society for Applied Microbiology
Journal of Applied Microbiology
Volume 113, Issue 5, pages 1228–1237, November 2012
How to Cite
Leclerque, A., Kleespies, R.G., Schuster, C., Richards, N.K., Marshall, S.D.G. and Jackson, T.A. (2012), Multilocus sequence analysis (MLSA) of ‘Rickettsiella costelytrae' and ‘Rickettsiella pyronotae’, intracellular bacterial entomopathogens from New Zealand. Journal of Applied Microbiology, 113: 1228–1237. doi: 10.1111/j.1365-2672.2012.05419.x
- Issue published online: 17 OCT 2012
- Article first published online: 24 AUG 2012
- Accepted manuscript online: 1 AUG 2012 04:56AM EST
- Manuscript Accepted: 28 JUL 2012
- Manuscript Revised: 12 JUL 2012
- Manuscript Received: 5 JUN 2012
- German Federal Office for Agriculture and Food. Grant Number: NZL 3/10-11
- microbial phylogenetics;
- molecular genetic;
Larvae of scarab beetles live in the soil and are frequently hosts for microbial pathogens. In New Zealand, larvae of the grass grub, Costelytrae zealandica (Coleoptera: Scarabaeidae), and manuka beetles, Pyronota spp. (Coleoptera: Scarabaeidae), have been collected from field populations showing loss of vigour and a whitened appearance. Diagnosis indicated an intracellular infection of fat body tissues by Rickettsiella-like micro-organisms. Rickettsiella bacteria are under evaluation as a possible new source of insect bio-control agents for important agricultural pests as, e.g. scarabaeid and elaterid larvae. The present study aimed at the unequivocal molecular taxonomic identification and comparison of the bacteria associated with Costelytra and Pyronota.
Methods and Results
Electron microscopy and phylogenetic reconstruction using a multilocus sequence analysis approach based on the 16S ribosomal RNA gene together with four protein-encoding markers (ftsY, gidA, rpsA, and sucB) demonstrated that both bacteria from New Zealand are phylogenetically closely related, but not identical, and belong to the taxonomic genus Rickettsiella.
The bacteria under study should be referred to as pathotypes ‘Rickettsiella costelytrae’ and ‘Rickettsiella pyronotae’, respectively. Moreover, on the basis of the currently accepted systematic organization of the genus Rickettsiella, both pathotypes should be considered synonyms of the nomenclatural type species, Rickettsiella popilliae.
Significance and Impact of the Study
The study demonstrates that Rickettsiella bacteria are geographically widespread pathogens of scarabaeid larvae. Implications of the phylogenetic findings presented for the stability of host adaptation by Rickettsiella bacteria are critically discussed.