Publications

3843

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.

ABSTRACT The 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 louse Pediculus humanus and provide new characterizations of the P-endosymbionts from Pediculus schaeffi from chimpanzees and Pthirus 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 “ Candidatus Arsenophonus insecticola.” We propose that two additional species be added to the genus “ Candidatus Riesia.” The new species proposed within “ Candidatus Riesia” 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 for Buchnera , 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.

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 order Methanobacteriales in the genus Methanobrevibacter. Strains ZA-10T and KM1H5-1PT gained energy for growth by the reduction of CO2 to CH4 using H2 or formate exclusively as electron donors. Increasing formate concentrations to 220 mM in batch cultures increased the growth of strain KM1H5-1PT but 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 genus Methanobrevibacter. Strains ZA-10T and KM1H5-1PT showed 16S rRNA gene sequence similarity of 98.0 and 98.6 % to their closest recognized relatives, Methanobrevibacter thaueri CWT and Methanobrevibacter ruminantium M1T, 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-10T and Methanobrevibacter thaueri CWT and <25 % between strains KM1H5-1PT and Methanobrevibacter ruminantium M1T. Based on the data presented, the new strains are considered to represent two novel species of the genus Methanobrevibacter, for which the names Methanobrevibacter millerae sp. nov. (type strain ZA-10T=DSM 16643T=OCM 820T) and Methanobrevibacter olleyae sp. nov. (type strain KM1H5-1PT=DSM 16632T=OCM 841T) are proposed.

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.

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.