Publications

4476

Cacti (Opuntia spp.) are perennial, evergreen, succulent plants native to arid areas of the Americas. Because of their aesthetic appearance, many cacti have been cultivated and introduced to other parts of the world as ornamentals. Cacti are susceptible to phytoplasma infections and develop witches'-broom (WB) disease. Currently, all reported cactus WB cases are associated with infections by phytoplasmas in the peanut witches'-broom group (16SrII) (1,2,4). During a phytoplasma diversity survey carried out during 2004 in Yunnan, China, we collected 29 malformed and 14 healthy-looking naturally occurring cactus plants from 14 locations representing five geographical regions. Each of the 29 malformed plants exhibited stunted growth and possessed clusters of highly proliferating cladodia, typical symptoms of cactus WB disease. Nested-PCR was carried out on the DNA samples extracted from young cladodia of these plants using phytoplasma-universal 16S rDNA primers P1A/P7A and R16F2n/R16R2 (3). Results revealed that all 29 diseased plants that were examined were infected by phytoplasmas, whereas all 14 healthy-looking plants were negative for phytoplasmas. Subsequent restriction fragment length polymorphism (RFLP) analysis of the PCR-amplified 1.25-kb 16S rDNA fragments indicated that 28 diseased plants were infected by a phytoplasma of group 16SrII, whereas one plant (from Suan Village) was infected by a ‘Candidatus Phytoplasma asteris’-related (group 16SrI) phytoplasma designated as strain YN26. Nucleotide sequence analysis of the strain YN26 partial rRNA operon (GenBank Accession No. EF190970), covering a near full-length 16S rRNA gene, a 16S-23S rRNA intergenic spacer, a tRNA-Ile gene, and a partial 23S rRNA gene, suggested that this phytoplasma is most closely related to an ash witches'-broom phytoplasma (GenBank Accession No. AY566302, 99.7% identity) and an epilobium phyllody phytoplasma (GenBank Accession No. AY101386, 99.7% identity), both members of subgroup16SrI-B. This YN26-infected cactus plant was transferred to a greenhouse and maintained for more than 2 years, during which time DNA samples were extracted and tested two additional times. The same 16S rDNA RFLP pattern type was consistently obtained in these tests, confirming that the plant remained infected by the 16SrI phytoplasma. To our knowledge, this is the first report of a natural infection of a cactus species by a group 16SrI phytoplasma. Since this 16SrI-cactus WB phytoplasma was found in the same geographical location where 16SrII-cactus WB phytoplasma was detected both in this and a previous study (1), the findings raised the question whether 16SrI- and 16SrII-cactus WB phytoplasmas have overlapping geo- and bioecological niches. References: (1) H. Cai et al. Plant Pathol. 51:394, 2002. (2) E. Choueiri et al. Plant Dis. 89:1129, 2005. (3) I. M. Lee et al. Int. J. Syst. Evol. Microbiol 54:337, 2004. (4) N. Leyva-Lopez et al. Phytopathology (Abstr.) 89(suppl):S45, 1999.

A Gram-negative, chemoheterotrophic, facultatively anaerobic coccus, designated IMCC1545T, was isolated from the digestive tract of a marine clamworm, Periserrula leucophryna, inhabiting a tidal flat of the Yellow Sea. Cells of strain IMCC1545T are non-motile, dividing by binary fission. The predominant fatty acids are anteiso-C15 : 0 and C18 : 0. The respiratory quinone is menaquinone-7 and the DNA G+C content is 52.1 mol%. Phylogenetic analyses based on 16S rRNA gene sequences using three treeing algorithms revealed that the strain formed a novel genus-level lineage within the phylum ‘Verrucomicrobia’. The most closely related named organisms to strain IMCC1545T are ‘Fucophilus fucoidanolyticus’ SI-1234 (86.5 % 16S rRNA gene sequence similarity), Alterococcus agarolyticus ADT3T (81.8 %) and Opitutus terrae PB90-1T (80.3 %), which belong to subdivision 4 of the ‘Verrucomicrobia’. Subdivision 4 of the ‘Verrucomicrobia’ (here named Opitutae classis nov.) was divided into two clades, a clade containing strain IMCC1545T and a clade containing Opitutus terrae. From the taxonomic data obtained in this study, it is proposed that the new marine isolate be placed into a novel genus and species named Puniceicoccus vermicola gen. nov., sp. nov. (the type strain of Puniceicoccus vermicola is IMCC1545T=KCCM 42343T=NBRC 101964T) within Puniceicoccaceae fam. nov and Puniceicoccales ord. nov in the class Opitutae. The family Opitutaceae fam. nov. and order Opitutales ord. nov. are also formally proposed.

ABSTRACTThe primary endosymbiotic bacteria from three species of parasitic primate lice were characterized molecularly. We have confirmed the characterization of the primary endosymbiont (P-endosymbiont) of the human head/body lousePediculus humanusand provide new characterizations of the P-endosymbionts fromPediculus schaeffifrom chimpanzees andPthirus pubis, the pubic louse of humans. The endosymbionts show an average percent sequence divergence of 11 to 15% from the most closely related known bacterium “CandidatusArsenophonus insecticola.” We propose that two additional species be added to the genus “CandidatusRiesia.” The new species proposed within “CandidatusRiesia” have sequence divergences of 3.4% and 10 to 12% based on uncorrected pairwise differences. Our Bayesian analysis shows that the branching pattern for the primary endosymbionts was the same as that for their louse hosts, suggesting a long coevolutionary history between primate lice and their primary endosymbionts. We used a calibration of 5.6 million years to date the divergence between endosymbionts from human and chimpanzee lice and estimated an evolutionary rate of nucleotide substitution of 0.67% per million years, which is 15 to 30 times faster than previous estimates calculated forBuchnera, the primary endosymbiont in aphids. Given the evidence for cospeciation with primate lice and the evidence for fast evolutionary rates, this lineage of endosymbiotic bacteria can be evaluated as a fast-evolving marker of both louse and primate evolutionary histories.

ABSTRACT Both Helicobacter pylori and “ Candidatus Helicobacter heilmannii” infections are associated with peptic ulcers, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue (MALT) lymphomas. However, good animal models of H. pylori clinical diseases are rare. In this study, we aimed to establish an animal model of “ Candidatus Helicobacter heilmannii” gastric MALT lymphoma. We used a urease-positive gastric mucosal and mucus homogenate from a cynomolgus monkey maintained in C57BL/6 mouse stomachs. The bacterium in the homogenate was identified as “ Candidatus Helicobacter heilmannii” based on a DNA sequence analysis of the 16S rRNA and urease genes. Mucosal and mucus homogenates were used to inoculate C57BL/6 mice, which were then examined for 24 months. We observed a gradual increase in the surface area of protrusive lesions in almost all infected C57BL/6 mouse fundic stomachs 6 months after infection. Light microscopic observations revealed an accumulation of B lymphocytes along with destruction of glandular elements and the presence of lymphoepithelial lesions consistent with low-grade MALT lymphomas. Electron microscopic observation revealed numerous “ Candidatus Helicobacter heilmannii” bacilli in the fundic glandular lumen, the intracellular canaliculi, and the cytoplasm of intact cells, as well as damaged parietal cells. In conclusion, “ Candidatus Helicobacter heilmannii” induced gastric MALT lymphomas in almost 100% of infected C57BL/6 mice after a 6-month period associated with the destruction of parietal cells.

The purpose of this announcement is to effect the valid publication of the following new names and new combinations under the procedure described in the Bacteriological Code (1990 Revision). Authors and other individuals wishing to have new names and/or combinations included in future lists should send three copies of the pertinent reprint or photocopies thereof, or an electronic copy of the published paper, to the IJSEM Editorial Office for confirmation that all of the other requirements for valid publication have been met. It is also a requirement of IJSEM and the ICSP that authors of new species, new subspecies and new combinations provide evidence that types are deposited in two recognized culture collections in two different countries (i.e. documents certifying deposition and availability of type strains). It should be noted that the date of valid publication of these new names and combinations is the date of publication of this list, not the date of the original publication of the names and combinations. The authors of the new names and combinations are as given below, and these authors' names will be included in the author index of the present issue and in the volume author index. Inclusion of a name on these lists validates the publication of the name and thereby makes it available in bacteriological nomenclature. The inclusion of a name on this list is not to be construed as taxonomic acceptance of the taxon to which the name is applied. Indeed, some of these names may, in time, be shown to be synonyms, or the organisms may be transferred to another genus, thus necessitating the creation of a new combination.

Four formate-utilizing methanogens were isolated from ovine (strain KM1H5-1PT) and bovine (strains AK-87, OCP and ZA-10T) rumen contents. Based on 16S rRNA gene sequence analysis, the methanogen strains were found to belong to the orderMethanobacterialesin the genusMethanobrevibacter. Strains ZA-10Tand KM1H5-1PTgained energy for growth by the reduction of CO2to CH4using H2or formate exclusively as electron donors. Increasing formate concentrations to 220 mM in batch cultures increased the growth of strain KM1H5-1PTbut did not affect the growth of strain ZA-10T. Substrate specificity and resistance to cell-wall lysis supported the affiliation of the strains to the genusMethanobrevibacter. Strains ZA-10Tand KM1H5-1PTshowed 16S rRNA gene sequence similarity of 98.0 and 98.6 % to their closest recognized relatives,Methanobrevibacter thaueriCWTandMethanobrevibacter ruminantiumM1T, respectively. DNA–DNA hybridization experiments indicated that the strains were not affiliated at the species level to their closest recognized relatives, with DNA reassociation values of only 28 % between strains ZA-10TandMethanobrevibacter thaueriCWTand <25 % between strains KM1H5-1PTandMethanobrevibacter ruminantiumM1T. Based on the data presented, the new strains are considered to represent two novel species of the genusMethanobrevibacter, for which the namesMethanobrevibacter milleraesp. nov. (type strain ZA-10T=DSM 16643T=OCM 820T) andMethanobrevibacter olleyaesp. nov. (type strain KM1H5-1PT=DSM 16632T=OCM 841T) are proposed.

Hemoplasmas are known causes of anemia in some cats and some Bartonella species have been associated with anemia in people and in dogs. In this retrospective study, we used polymerase chain reaction (PCR) assays to determine the prevalence rates of Mycoplasma haemofelis, ‘ Candidatus M haemominutum’, A phagocytophilum, Ehrlichia species, and Bartonella species DNA in the blood of cats with anemia and a control group of healthy cats. DNA of the organisms was amplified from 22 of 89 cats with anemia (24.7%) and 20 of 87 healthy cats (23.0%). DNA of a hemoplasma was amplified from 18 of 89 cats with anemia (20.2%) and 13 of 87 healthy cats (14.9%); DNA of a Bartonella species was amplified from five of 89 cats with anemia (5.6%) and seven of 87 healthy cats (8.0%). There were no statistically significant differences detected between groups.

Summary Studies were conducted in opposing gradients of oxygen and sulfide in microslide capillaries to (i) characterize the chemical microenvironment preferred by Candidatus Arcobacter sulfidicus, a highly motile, sulfur‐oxidizing bacterium that produces sulfur in filamentous form, and (ii) to develop a model describing the mechanism of filamentous‐sulfur formation. The highly motile microorganisms are microaerophilic, with swarms effectively aggregating within oxic‐anoxic interfaces by exhibiting a chemotactic response. The position of the band was found to be largely independent of the sulfide concentration as it always formed at the oxic‐anoxic interface. Flux calculations based on steady state gradients of oxygen and sulfide indicate that sulfide is incompletely oxidized to sulfur, in line with the formation of filamentous sulfur by these organisms. It is proposed that Candidatus Arcobacter sulfidicus effectively competes with other sulfur‐oxidizing bacteria in the environment by being able to tolerate higher concentrations of hydrogen sulfide (1–2 mM) and by possessing the ability to grow at very low oxygen concentrations (1–10 μM). The formation of mat‐like structures from filamentous sulfur appears to be a population mediated effort allowing these organisms to effectively colonize environments characterized by high sulfide, low oxygen and dynamic fluid movement.