Downloaded from www.microbiologyresearch.org by IP: 93.91.26.109 On: Wed, 06 Jan 2016 13:55:39 Photorhabdus heterorhabditis sp. nov., a symbiont of the entomopathogenic nematode Heterorhabditis zealandica Tiarin Ferreira, 1 Carol A. van Reenen, 2 Akihito Endo, 2 Patrick Tailliez, 3,4 Sylvie Page ` s, 3,4 Cathrin Spro ¨ er, 5 Antoinette P. Malan 1 and Leon M. T. Dicks 2 Correspondence Leon M. T. Dicks lmtd@sun.ac.za 1 Department of Conservation Ecology and Entomology, Stellenbosch University, Private Bag X1, 7602 Matieland, Stellenbosch, South Africa 2 Department of Microbiology, Stellenbosch University, Private Bag X1, 7602 Matieland, Stellenbosch, South Africa 3 Universite ´ Montpellier 2, UMR1333 Diversite ´ , Ge ´ nomes & Interactions Microorganismes-Insectes (DGIMI), F-34000 Montpellier, France 4 INRA, UMR1333 Diversite ´, Ge ´ nomes & Interactions Microorganismes-Insectes (DGIMI), F-34000 Montpellier, France 5 DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen, Inhoffenstrasse 7B, 38124 Braunschweig, Germany The bacterial symbionts SF41 T and SF783 were isolated from populations of the insect pathogenic nematode Heterorhabditis zealandica collected in South Africa. Both strains were closely related to strain Q614 isolated from a population of Heterorhabditis sp. collected from soil in Australia in the 1980s. Sequence analysis based on a multigene approach, DNA–DNA hybridization data and phenotypic traits showed that strains SF41 T , SF783 and Q614 belong to the same species of the genus Photorhabdus with Photorhabdus temperata subsp. cinerea as the most closely related taxon (DNA–DNA hybridization value of 68 %). Moreover, the phylogenetic position of Photorhabdus temperata subsp. cinerea DSM 19724 T initially determined using the gyrB sequences, was reconsidered in the light of the data obtained by our multigene approach and DNA–DNA hybridization experiments. Strains SF41 T , SF783 and Q614 represent a novel species of the genus Photorhabdus, for which the name Photorhabdus heterorhabditis sp. nov. is proposed (type strain SF41 T 5ATCC BAA-2479 T 5DSM 25263 T ). Photorhabdus bacteria are symbiotically associated with entomopathogenic nematodes of the genus Heterorhabditis, contributing actively to the biological cycle of their host. The Heterorhabditidae family of nematodes consists of obligate insect pathogens. The nematodes and bacteria work together to overcome the immune response of their insect host, thus allowing the bacteria to proliferate. Developing nematodes feed on a mixture of bacteria and bioconverted host tissue, enabling them to produce one to three generations until the food resources in the cadaver are depleted (Koppenho ¨fer, 2007). At the time of writing, three species of the genus Photor- habdus have been described, Photorhabdus luminescens (Thomas & Poinar, 1979, Boemare et al., 1993), Photor- habdus asymbiotica and Photorhabdus temperata (Fischer-Le Saux et al., 1999). In addition, nine subspecies of Photorhabdus luminescens, three subspecies of Photorhabdus temperata and two subspecies of Photorhabdus asymbiotica have been described. The subspecies of Photorhabdus luminescens are: Photorhabdus luminescens subsp. akhurstii and Photorhabdus luminescens subsp. laumondii (Fischer-Le Saux et al., 1999), Photorhabdus luminescens subsp. caribbea- nensis and Photorhabdus luminescens subsp. hainanensis (Tailliez et al., 2010), Photorhabdus luminescens subsp. kayaii (Hazir et al., 2004), Photorhabdus luminescens subsp. kleinii (An & Grewal, 2011), Photorhabdus luminescens subsp. luminescens (Thomas & Poinar, 1979; Boemare et al., 1993), Photorhabdus luminescens subsp. noenieputensis (Ferreira et al. , 2013a) and ‘Photorhabdus luminescens subsp. sonorensis’ The GenBank/EMBL/DDBJ accession numbers for the partial 16S rRNA gene, recA, dnaN, gltX, gyrB and infB sequences of strain SF41 T are HQ142626, and KF418141–KF418145, respectively, and those for strain SF783 are KF418146–KF418151, respectively. Seven supplementary figures and a supplementary table are available with the online version of this paper. International Journal of Systematic and Evolutionary Microbiology (2014), 64, 1540–1545 DOI 10.1099/ijs.0.059840-0 1540 059840 G 2014 IUMS Printed in Great Britain