Publications

4690

Two strains (JC85T and JC108) of Gram-stain-negative, motile bacteria were isolated from endolithic beach sand samples on an oligotrophic medium. Based on the 16S rRNA gene sequence analysis, both strains were identified as belonging to the genus Rhizobium . Strain JC108 had 16S rRNA gene sequence similarity of 100 % with Rhizobium pusense NRCPB10T and formed a cluster with this strain. Strain JC85T had 96.9 % 16S rRNA gene sequence similarity and was 18 % related (based on DNA–DNA hybridization) to Rhizobium borbori DN316T. With other strains of the genus Rhizobium , the 16S rRNA gene sequence similarity was less than 96.3 %. Strain JC85T could tolerate up to 3 % salinity, fix N2, was resistant to ampicillin (10 µg) and was positive for catalase and oxidase. The major fatty acid was C18 : 1ω7c (69 %) with minor amounts of C19 : 0 cyclo ω8c (8.9 %), C16 : 0 (6.9 %), C12 : 0 (5.7 %) and C19 : 1ω7c/C19 : 1ω6c (2.2 %). Polar lipids of strain JC85T include two unidentified aminophospholipids (APL1,2), two unidentified phospholipids (PL1,2), phosphatidylcholine and four unidentified lipids (L1–4). Q-10 is the major quinone of strain JC85T. Based on polyphasic taxonomic analysis, strain JC85T represents a novel species for which, the name Rhizobium subbaraonis JC85T is proposed. The type strain is JC85T ( = DSM 24765T = KCTC 23614T).

ABSTRACT “ Candidatus Neoehrlichia mikurensis” was detected by PCR in 4.0% (34/841) of the rodents tested in this study. The 34 rodents represented nine species from seven regions of China. Phylogenetic analyses based on the partial groEL and nearly entire 16S rRNA gene sequences of the agent revealed genetic diversity, which was correlated with its geographic origins.

A phytoplasma was identified in naturally infected wild Balanites triflora plants exhibiting typical witches’ broom symptoms (Balanites witches’ broom: BltWB) in Myanmar. The 16S rRNA gene sequence revealed that BltWB phytoplasma had the highest similarity to that of ‘Candidatus Phytoplasma ziziphi’ and it was also closely related to that of ‘Candidatus Phytoplasma ulmi ’. Phylogenetic analysis of the 16S rRNA gene sequences indicated that the BltWB phytoplasma clustered as a discrete subclade with Elm yellows phytoplasmas. RFLP analysis of the 16S rRNA gene including the 16S–23S spacer region differentiated the BltWB phytoplasma from ‘Ca. P. ziziphi ’, ‘Ca. P. ulmi ’ and ‘Candidatus Phytoplasma trifolii ’. Analysis of additional ribosomal protein (rp) and translocase protein (secY) gene sequences and phylogenetic analysis of BltWB showed that this phytoplasma was clearly distinguished from those of other ‘Candidatus Phytoplasma ’ taxa. Taking into consideration the unique plant host and the restricted geographical occurrence in addition to the 16S rRNA gene sequence similarity, the BltWB phytoplasma is proposed to represent a novel taxon, ‘Candidatus Phytoplasma balanitae’.

X-disease is one of the most serious diseases known in peach (Prunus persica). Based on RFLP analysis of 16S rRNA gene sequences, peach X-disease phytoplasma strains from eastern and western United States and eastern Canada were classified in 16S rRNA gene RFLP group 16SrIII, subgroup A. Phylogenetic analyses of 16S rRNA gene sequences revealed that the X-disease phytoplasma strains formed a distinct subclade within the phytoplasma clade, supporting the hypothesis that they represented a lineage distinct from those of previously described ‘Candidatus Phytoplasma ’ species. Nucleotide sequence alignments revealed that all studied X-disease phytoplasma strains shared less than 97.5 % 16S rRNA gene sequence similarity with previously described ‘Candidatus Phytoplasma ’ species. Based on unique properties of the DNA, we propose recognition of X-disease phytoplasma strain PX11CT1R as representative of a novel taxon, ‘Candidatus Phytoplasma pruni’. Results from nucleotide and phylogenetic analyses of secY and ribosomal protein (rp) gene sequences provided additional molecular markers of the ‘Ca. Phytoplasma pruni’ lineage. We propose that the term ‘Ca. Phytoplasma pruni’ be applied to phytoplasma strains whose 16S rRNA gene sequences contain the oligonucleotide sequences of unique regions that are designated in the formally published description of the taxon. Such strains include X-disease phytoplasma and - within the tolerance of a single base difference in one unique sequence - peach rosette, peach red suture, and little peach phytoplasmas. Although not employed for taxon delineation in this work, we further propose that secY, rp, and other genetic loci from the reference strain of a taxon, and where possible oligonucleotide sequences of unique regions of those genes that distinguish taxa within a given 16Sr group, be incorporated in emended descriptions and as part of future descriptions of ‘Candidatus Phytoplasma ’ taxa.

ABSTRACT Bemisia tabaci (Hemiptera: Aleyrodidae) is a species complex containing >28 cryptic species, some of which are important crop pests worldwide. Like many other sap-sucking insects, whiteflies harbor an obligatory symbiont, “ Candidatus Portiera aleyrodidarum,” and a number of secondary symbionts. So far, six genera of secondary symbionts have been identified in B. tabaci . In this study, we report and describe the finding of an additional bacterium in the indigenous B. tabaci cryptic species China 1 (formerly known as B. tabaci biotype ZHJ3). Phylogenetic analysis based on the 16S rRNA and gltA genes showed that the bacterium belongs to the Alphaproteobacteria subdivision of the Proteobacteria and has a close relationship with human pathogens of the genus Orientia . Consequently, we temporarily named it Orientia -like organism (OLO). OLO was found in six of eight wild populations of B. tabaci China 1, with the infection rate ranging from 46.2% to 76.8%. Fluorescence in situ hybridization (FISH) of B. tabaci China 1 in nymphs and adults revealed that OLOs are confined to the bacteriome and co-occur with “ Ca . Portiera aleyrodidarum.” The vertical transmission of OLO was demonstrated by detection of OLO at the anterior pole end of the oocytes through FISH. Quantitative PCR analysis of population dynamics suggested a complex interaction between “ Ca . Portiera aleyrodidarum” and OLO. Based on these results, we propose “ Candidatus Hemipteriphilus asiaticus” for the classification of this symbiont from B. tabaci .

A novel bacterial strain designated HA-01T was isolated from a freshwater terrestrial hot spring located at Hot Springs National Park, Arkansas, USA. Cells were Gram-negative-staining, rod-shaped, aerobic, chemo-organotrophic, oxidase- and catalase-positive, non-spore-forming and motile by means of a single polar flagellum. Growth occurred at 37–60 °C, with an optimum between 45 and 50 °C, and at pH 6.5–8.5, with an optimum between pH 6.5 and 7.0. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the closest relatives of strain HA-01T were Solimonas aquatica NAA-16T (93.8 %), Solimonas flava CW-KD 4T (94.1 %), Solimonas soli DCY12T (93.1 %), Solimonas variicoloris MN28T (94.0 %), Nevskia ramosa Soe1T (91.2 %) and Hydrocarboniphaga effusa AP103T (91.1 %). Major fatty acids consisted of C16 : 0, iso-C16 : 0, C16 : 1ω5c and summed feature 8 (C18 : 1ω9c, C18 : 1ω7c and C18 : 1ω6c). Polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine, and the major isoprenoid quinone was Q-8. The DNA G+C content was 64.4 mol%. Based on phylogenetic, phenotypic and chemotaxonomic evidence, it is proposed that strain HA-01T represents a novel species in a new genus for which the name Fontimonas thermophila gen. nov., sp. nov. is proposed. The type strain of the type species is HA-01T ( = DSM 23609T = CCUG 59713T). A new family, Solimonadaceae fam. nov., is also proposed to replace Sinobacteriaceae Zhou et al. 2008.