Publications

4685

Two Gram-negative, facultatively anaerobic, rod-shaped bacteria, strains EF212Tand PS125T, were isolated from the octocoralsEunicea fuscaandPlexaurasp., respectively. EF212Twas isolated from a specimen ofE. fuscacollected off the coast of Florida, USA, and PS125Twas isolated from a specimen ofPlexaurasp. collected off the coast of Bimini, Bahamas. Analysis of the nearly full-length 16S rRNA gene sequences showed that these novel strains were most closely related toEndozoicomonas montiporaeCL-33T,E. elysicolaMKT110TandE. numazuensisHC50T(EF212T, 95.6–97.2 % identity; PS125T, 95.1–96.4 % identity). DNA–DNA hybridization values among EF212T, PS125T,E. montiporaeLMG 24815TandE. elysicolaKCTC 12372Twere far below the 70 % cut-off, with all values for duplicate measurements being less than 35 %. Both EF212Tand PS125Trequired NaCl for growth and showed optimal growth at 2–3 % NaCl, 22-30 °C and pH 8.0. The predominant cellular fatty acids were summed feature 3 (C16 : 1ω6cand/or C16 : 1ω7c), summed feature 8 (C18 : 1ω6cand/or C18 : 1ω7c), C16 : 0and C14 : 0. The DNA G+C content of EF212Twas 48.6 mol% and that of PS125Twas 47.5 mol%. In addition to the genotypic differences observed between the two novel strains and related type strains, phenotypic and chemotaxonomic experiments also revealed differences between strains. Thus, strains EF212Tand PS125Trepresent novel species of the genusEndozoicomonas, for which the namesEndozoicomonas euniceicolasp. nov. andEndozoicomonas gorgoniicolasp. nov., respectively, are proposed. The type strains are EF212T( = NCCB 100458T = DSM 26535T) forEndozoicomonas euniceicolasp. nov. and PS125T( = NCCB 100438T = CECT 8353T) forEndozoicomonas gorgoniicolasp. nov. An emended description of the genusEndozoicomonasis also provided to encompass differences observed in the results of genotypic, chemotaxonomic and phenotypic tests compared from the original and amended genus descriptions.

ABSTRACT A recently described clinical isolate, “ Candidatus Bartonella ancashi,” was obtained from a blood sample of a patient presenting with verruga peruana in the Ancash region of Peru. This sample and a second isolate obtained 60 days later from the same patient were molecularly typed using multilocus sequence typing (MLST) and multispacer sequence typing (MST). The isolates were 100% indistinguishable from each other but phylogenetically distant from Bartonella bacilliformis and considerably divergent from other known Bartonella species, confirming their novelty.

ABSTRACT “ Candidatus Cardinium hertigii” ( Bacteroidetes ) is a maternally inherited endosymbiont known from several arthropods. Its mechanisms for persistence in host populations are mostly reproductive manipulation, though it has been occasionally reported to improve fitness parameters in several hosts. In Culicoides (Diptera: Ceratopogonidae) biting midges, the prevalence of “ Candidatus Cardinium” infection was documented as moderate, with no detectable sex bias. We therefore investigated whether “ Candidatus Cardinium” affects important fitness parameters, such as survival and body size, in Culicoides imicola , a dominant vector species. Field-collected midges were trapped and analyzed for survival under different environmental conditions and antibiotic treatment, taking into account “ Candidatus Cardinium” infection status and parity status (i.e., parous or nulliparous). Additionally, wing lengths were measured as a proxy parameter for body size and analyzed together with “ Candidatus Cardinium” infection data. The findings revealed no difference in survival of Culicoides infected with “ Candidatus Cardinium” and that of uninfected midges in both parity states and under all tested conditions: optimal, starvation, heat, and antibiotic treatment. Beyond survival, no wing length difference was found for “ Candidatus Cardinium”-infected versus uninfected midges. In aggregate, these findings support our conclusion that “ Candidatus Cardinium” does not have an overt effect on the survival and size of adult C. imicola midges. “ Candidatus Cardinium” may affect immature stages or may alter adult reproductive performance.

A new species of Hassallia (Cyanobacteria, Nostocales, Microchaetaceae) from a supralittoral tropical marine biotope is described. Hassallia littoralis is a false-branched nostocalean cyanobacterium with caespitose free filaments or with fasciculated individual filaments not in a common sheath. Filaments are mainly heteropolar, bearing mono- and bi-pored heterocysts and isopolar or heteropolar hormogonia. The sheath is often widening, with pronounced rounded terminals. This new species is defined according to molecular, morphological and ecological criteria, considering data from different stages of its life cycle as well as the 16S rRNA partial gene sequence.

Based on an earlier survey of putative psyllid vectors of apple proliferation (AP), carried out in 2009 and 2010, Cacopsylla picta (Förster) populations infected with ‘Candidatus Phytoplasma mali’ were detected in at least two commercial apple (Malus domestica Borkh.) orchards in southern Finland (1). To establish the presence of ‘Ca. P. mali’ in apple trees, a survey was conducted in 17 commercial apple orchards in August 2012. Phytosanitary inspectors tracked the source of the ‘Ca. P. mali’ by collecting 33 leaf samples from trees showing probable symptoms. Typical symptoms, including elongated stipules and witches' broom, were rare. Total DNA was extracted from leaves using a DNeasy Plant Mini Kit (Qiagen, Hilden, Germany) and screened for ‘Ca. P. mali’ with real-time PCR (2) and the commercial Apple Proliferation Group – complete PCR reaction kit (Loewe Biochemica GmbH, Sauerlach, Germany). Two samples tested positive and results were confirmed with TaqMan PCR and conventional PCR assays and DNA sequencing in the Food and Environment Research Agency (Fera), in the United Kingdom. One positive sample was taken from an orchard in Lohja, southern Finland, where high ‘Ca. P. mali’ incidence in overwintered C. picta was observed in 2010 (1). ‘Ca. P. mali’ was found in a >40-year-old ‘Red Melba’ tree with witches' broom but without elongated stipule symptoms. The other positive sample was collected from an orchard in the Aland Islands, where the infected ‘Lobo’ tree showed symptoms of elongated stipules. This orchard was not monitored for AP vectors. No small fruit symptoms were noted by inspectors or growers in either of the orchards. The positive samples were further analyzed for subtypes using PCR/RFLP and primers AP13/AP10 (3). The amplicons (776 bp) were sequenced and digested with HincII and BspHI (New England BioLabs Inc., Ipswich, MA) following manufacturer's instructions. Both samples proved to be apple proliferation subtypes AT-1 on the basis of RFLP and the sequenced 776-bp region. Sequences of the 776-bp amplicon of the Lohja and Aland isolates showed 100% and 99% identity, respectively, with sequences of apple proliferation isolates (accession nos. L22217.1 and CU469464.1) in GenBank. Both suspected psyllid vectors of ‘Ca. P. mali’ C. picta and C. melanoneura (Förster) occur in Finland, but their distribution, abundance, and transmission specificity is inadequately documented. The next step to evaluate the risk of spread of apple proliferation in commercial orchards is an extensive survey of the occurrence of Cacopsylla species infected with ‘Ca. P. mali’. References: (1) A. Lemmetty et al. B. Insectol. 64:257, 2011. (2) P. Nikolić et al. Mol. Cell. Probes. 24:303, 2010. (3) W. Jarausch et al. Mol. Cell. Probes 14:17, 2000.

Cyanobacteria were responsible for the oxygenation of the ancient atmosphere; however, the evolution of this phylum is enigmatic, as relatives have not been characterized. Here we use whole genome reconstruction of human fecal and subsurface aquifer metagenomic samples to obtain complete genomes for members of a new candidate phylum sibling to Cyanobacteria, for which we propose the designation ‘Melainabacteria’. Metabolic analysis suggests that the ancestors to both lineages were non-photosynthetic, anaerobic, motile, and obligately fermentative. Cyanobacterial light sensing may have been facilitated by regulators present in the ancestor of these lineages. The subsurface organism has the capacity for nitrogen fixation using a nitrogenase distinct from that in Cyanobacteria, suggesting nitrogen fixation evolved separately in the two lineages. We hypothesize that Cyanobacteria split from Melainabacteria prior or due to the acquisition of oxygenic photosynthesis. Melainabacteria remained in anoxic zones and differentiated by niche adaptation, including for symbiosis in the mammalian gut.