title: Real-time PCR detection and phylogenetic relationships of Neorickettsia spp. in digeneans from Egypt, Philippines, Thailand, Vietnam and the United States.
abstract: Neorickettsia (Rickettsiales, Anaplasmataceae) is a genus of obligate intracellular bacterial endosymbionts of digeneans (Platyhelminthes, Digenea). Some Neorickettsia are able to invade cells of the digenean's vertebrate host and are known to cause diseases of domestic animals, wildlife, and humans. In this study we report the results of screening digenean samples for Neorickettsia collected from bats in Egypt and Mindoro Island, Philippines, snails and fishes from Thailand, and fishes from Vietnam and the USA. Neorickettsia were detected using a real-time PCR protocol targeting a 152bp fragment of the heat shock protein coding gene, GroEL, and verified with nested PCR and sequencing of a 1853bp long region of the GroESL operon and a 1371bp long region of 16S rRNA. Eight unique genotypes of Neorickettsia were obtained from digenean samples. Neorickettsia sp. 8 obtained from Lecithodendrium sp. from Egypt; Neorickettsia sp. 9 and 10 obtained from two species of Paralecithodendrium from Mindoro, Philippines; Neorickettsia sp. 11 from Lecithodendrium sp. and Neorickettsia sp. 4 (previously identified from Saccocoelioides lizae, from China) from Thailand; Neorickettsia sp. 12 from Dicrogaster sp. Florida, USA; Neorickettsia sp. 13 and SF agent from Vietnam. Sequence comparison and phylogenetic analysis demonstrated that the forms, provisionally named Neorickettsia sp. 8-13, represent new genotypes. We have for the first time detected Neorickettsia in a digenean from Egypt (and the African continent as a whole), the Philippines, Thailand and Vietnam based on PCR and sequencing evidence. Our findings suggest that further surveys from the African continent, SE Asia, and island countries are likely to reveal new Neorickettsia lineages as well as new digenean host associations.
authors: Department of Biology, Georgia Southern University, Statesboro, Georgia 30460, USA; Department of Biology, University of North Dakota, Grand Forks, North Dakota 58202, USA.
authors: Stephen E
authors: SE
authors: Greiman
authors: Department of Biology, University of North Dakota, Grand Forks, North Dakota 58202, USA.
authors: Jefferson A
authors: JA
authors: Vaughan
authors: Department of Zoology, Tanta University, 31527 Tanta, Egypt.
authors: Rasha
authors: R
authors: Elmahy
authors: Department of Helminthology, Mahidol University, Bangkok 10400, Thailand.
authors: Poom
authors: P
authors: Adisakwattana
authors: Institute of Ecology and Biological Resources, VAST, Nghiado, Caugiay, Hanoi, Vietnam.
authors: Nguyen
authors: N
authors: Van Ha
authors: Department of Coastal Sciences, University of Southern Mississippi, Ocean Springs, Mississippi, USA.
authors: Thomas J
authors: TJ
authors: Fayton
authors: Department of Zoology, Tanta University, 31527 Tanta, Egypt.
authors: Amal I
authors: AI
authors: Khalil
authors: Department of Biology, University of North Dakota, Grand Forks, North Dakota 58202, USA. Electronic address: vasyl.tkach@und.edu.
authors: Vasyl V
authors: VV
authors: Tkach
mesh_terms: D000818:Animals; D002590:Cestode Infections / Q000469:parasitology / Q000662:veterinary; D018834:Chaperonin 60 / Q000235:genetics; D002685:Chiroptera / Q000382:microbiology / Q000469:parasitology; D004534:Egypt; D005399:Fishes / Q000382:microbiology / Q000469:parasitology; D005838:Genotype; D006790:Host-Parasite Interactions; D006801:Humans; D041102:Neorickettsia / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D010679:Philippines; D010802:Phylogeny; D010986:Platyhelminths / Q000382:microbiology*; D016133:Polymerase Chain Reaction / Q000379:methods; D012336:RNA, Ribosomal, 16S; D017422:Sequence Analysis, DNA; D013785:Thailand / Q000453:epidemiology; D014201:Trematode Infections / Q000469:parasitology / Q000662:veterinary; D014481:United States / Q000453:epidemiology; D014744:Vietnam / Q000453:epidemiology
chemical_list: D018834:Chaperonin 60; D012336:RNA, Ribosomal, 16S
keywords: Africa; Digenea; Molecular phylogeny; Neorickettsia; North America; Real-time PCR; Southeast Asia