Applied and Environmental Microbiology (2004) 70, 2596-2602

Tiziana Beninati, Nathan Lo, Luciano Sacchi, Claudio Genchi, Hiroaki Noda and Claudio Bandi (2004)
A novel alpha-proteobacterium resides in the mitochondria of ovarian cells of the tick Ixodes ricinus
Applied and Environmental Microbiology 70 (5), 2596-2602
Abstract: An intracellular bacterium from Ixodes ricinus ticks collected in Italy was characterized by electron microscopy (EM), PCR sequencing of the 16S rRNA gene, molecular phylogenetic analysis, and in situ hybridization (ISH). This bacterium was shown by EM to be present in the cytoplasm, as well as in the mitochondria of ovarian cells. When universal 16S rRNA bacterial primers were used, PCR amplification of ovarian DNA followed by cloning and sequencing resulted in the same sequence being found in each sample. Phylogenetic analysis of this sequence showed that the bacterium from which it was derived, tentatively designated IricES1, is part of a novel clade in the alpha subdivision of the Proteobacteria. ISH and PCR assays of various tissues performed with oligonucleotides specific for the IricES1 16S rRNA showed that IricES1 is restricted to ovarian cells. Based on the results obtained, we inferred that the bacteria seen by EM in ovarian cells are a single type of bacteria, corresponding to IricES1. PCR screening of 166 ticks from various parts of Italy and one site in England showed that IricES1 was present in 96% of adult females and 44% of nymphs (unsexed). No adult males were found to be infected. Despite the apparent parasitism of host mitochondria by IricES1, the available information suggests that the bacterium has an obligate relationship with its host, although this must be confirmed.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Nathan Lo

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Ixodes ricinus		Italy
	Ixodes ricinus		United Kingdom