Publications

4468

A comparison of the quantification of a specific microbial group in activated sludge by fluorescent in‐situ hybridization, coupled with either direct microscopic counting or flow cytometry, was performed using an enhanced‐biological‐phosphorus‐removal, sequencing‐batch reactor. The population dynamics of Candidatus Accumulibacter phosphatis (Cand. A. phosphatis) was evaluated during two separate runs of the reactor. With the operational conditions used, Cand. A. phosphatis was enriched until a failure in the pH controller eliminated its ecological advantage. As a result, the comparison of quantification techniques included Cand. A. phosphatis concentrations as low as 11% and as high as 96% of the total cells in the samples. The analysis demonstrated that, regardless of the particular limitations of each technique, both provided similar results when the activated‐sludge flocs were easily dispersed. However, when the activated‐sludge samples contained flocs that were difficult to disperse, flow cytometry failed to provide quantitative results.

ABSTRACT Wild deer are one of the important natural reservoir hosts of several species of Ehrlichia and Anaplasma that cause human ehrlichiosis or anaplasmosis in the United States and Europe. The primary aim of the present study was to determine whether and what species of Ehrlichia and Anaplasma naturally infect deer in Japan. Blood samples obtained from wild deer on two major Japanese islands, Hokkaido and Honshu, were tested for the presence of Ehrlichia and Anaplasma by PCR assays and sequencing of the 16S rRNA genes, major outer membrane protein p44 genes, and groESL . DNA representing four species and two genera of Ehrlichia and Anaplasma was identified in 33 of 126 wild deer (26%). DNA sequence analysis revealed novel strains of Anaplasma phagocytophilum , a novel Ehrlichia sp., Anaplasma centrale , and Anaplasma bovis in the blood samples from deer. None of these have been found previously in deer. The new Ehrlichia sp., A. bovis , and A. centrale were also detected in Hemaphysalis longicornis ticks from Honshu Island. These results suggest that enzootic cycles of Ehrlichia and Anaplasma species distinct from those found in the United States or Europe have been established in wild deer and ticks in Japan.

A moderately thermophilic, anaerobic bacterium (strain SB91T) was isolated from a freshwater hot spring at Barguzin Valley, Buryatiya, Russia. Cells of strain SB91Twere straight to slightly curved rods, 0·5–0·6 μm in diameter and 3·0–7·0 μm in length. Formation of endospores was not observed. The temperature range for growth was 26–62 °C, with an optimum at 50 °C. The pH range for growth was 5·5–9·5, with an optimum at pH 7·5–8·0. The substrates utilized by strain SB91Tin the presence of 9,10-anthraquinone 2,6-disulfonate included peptone, tryptone, Casamino acids, yeast extract, beef extract, casein hydrolysate, alanine plus glycine, alanine plus proline,l-valine and n-propanol. Carbohydrates were not utilized. Strain SB91Treduced amorphous Fe(III) oxide, Fe(III) citrate, Fe(III) EDTA or Fe(III) nitrilotriacetate with peptone,l-valine or n-propanol as an electron donor. Strain SB91Treduced 9,10-anthraquinone 2,6-disulfonate, thiosulfate, elemental sulfur, fumarate and selenite. Strain SB91Tsurvived after exposure to gamma-radiation at a dose of 5·4 kGy. The G+C content of the DNA of strain SB91Twas 33 mol%. Analysis of the 16S rRNA gene sequence revealed that the isolated organism belonged to cluster XII of the clostridia. On the basis of its physiological properties and the results of phylogenetic analyses, it is proposed that strain SB91Trepresents the sole species of a novel genus,Tepidimicrobium; the nameTepidimicrobium ferriphilumgen. nov., sp. nov. is proposed, with strain SB91T(=DSM 16624T=VKM B-2348T) as the type strain.

Abstract: Phylogenetic analysis of five rickettsial genes (17‐kDa gene, gltA, ompB, ompA, and sca4) from two molecular isolates of Candidatus Rickettsia andeanae from two ticks (Amblyomma maculatum and Ixodes boliviensis) collected from two domestic horses living in two separate locations in northern Peru (Coletas and Naranjo) was conducted to more clearly characterize this recently reported novel spotted fever group (SFG) rickettsia. Following nested polymerase chain reaction (PCR) amplification of the17‐kDa gene, gltA, ompB, ompA, and sca4, amplicons were purified, sequenced, and compared to those downloaded from GenBank. Phylogenetic analyses of the Candidatus Rickettsia andeanae sequences generated from17‐kDa gene (483 bp), gltA (1185 bp), ompA (1598 bp), ompB (4839 bp), and sca4 (2634 bp) demonstrated that they aligned strongly with those of SFG rickettsiae. Moreover, the sequences of these five genes most closely aligned with the following rickettsiae: ompA: Rickettsia sp RpA4 (98.03%), R. sp DnS28 (97.90%), and R. rhipicephali and R. massiliae (97.11%); ompB: R. aeschlimannii (97.22%), R. rhipicephali (97.20%), and R. sp Bar 29 (97.10%); and sca4: R. massiliae (97.8%), R. rhipicephali, and R. slovaca (97.7%). These results from the additional phylogenetic analyses of Candidatus Rickettsia andeanae confirm its inclusion within, and distance and uniqueness from, other known SFG rickettsiae.