Publications

4525

ABSTRACT Here, we present the draft genome of the endosymbiont “ Candidatus Ruthia magnifica” UCD-CM, a member of the phylum Proteobacteria , found from the gills of a deep-sea giant clam, Calyptogena magnifica . The assembly consists of 1,160,249 bp contained in 18 contigs.

ABSTRACT “ Candidatus Arthromitus” sp. strain SFB-mouse-NL (SFB, segmented filamentous bacteria) is a commensal bacterium necessary for inducing the postnatal maturation of homeostatic innate and adaptive immune responses in the mouse gut. Here, we report the genome sequence of this bacterium, which sets it apart from earlier sequenced mouse SFB isolates.

ABSTRACT The endosymbiont of Acanthamoeba strain UWC8 is an obligate amoeba endosymbiont belonging to the family of “ Candidatus Midichloriaceae” in Rickettsiales. We report here the complete genome sequence of this bacterium, which should catalyze future studies of amoeba-symbiont interactions.

Candidatus Liberibacter asiaticus is a fastidious prokaryotic α-proteobacterium that has not been cultured as yet. It is the causative agent of Citrus Huanglongbing (HLB) is a disease that infects citrus plants causing huge losses to the citrus industry. The plants employ a variety of defense mechanisms to combat the pathogen attack which mainly involves the formation of reactive oxygen species (ROS) mainly hydrogen peroxide, peroxynitrite and organic hydroperoxides. The microbe on the other hand has antioxidant proteins that counter the reactive oxygen species. Peroxiredoxin (Prx) which is known to play a crucial role in peroxide detoxification is a super family of one of such antioxidant proteins. In this work, we have determined the crystal structure of Bacterioferritin Comigratory Protein (BCP) that belongs to 1-Cys Prx enzyme having peroxidatic/sulfenic acid cysteine (C-47) but lacks the resolving cysteine. Furthermore, we are investigating structural aspects to gain insight into the binding of different peroxide substrates at the active site. Site directed mutagenesis has been done to introduce the non-conserved resolving cysteine to study its effect on peroxidase activity in both wild type and mutant form. Biochemically, both BCP 1-cys and BCP 2-cys have shown peroxidase activity. DNA protection activity against oxidative damage and cell-line based assays has implicated its protective role towards the hypoxic condition of cells. Hence, the protein becomes a lucrative target for ligands which might be potential antimicrobials.

Anaplasma platys ( Apl), ‘ Candidatus Mycoplasma haemominutum’ ( CMh), Bartonella henselae ( Bh) and Bartonella koehlerae ( Bk) were confirmed by polymerase chain reaction (PCR) amplification and DNA sequencing in a cat diagnosed with multiple myeloma. Other inconsistently documented hematologic abnormalities included anemia, thrombocytopenia, eosinophilia and hypoglycemia. Persistent Apl infection was confirmed for the first time in a North American cat by sequencing three bacterial genes ( 16S rRNA, p44 and GroEL) in peripheral blood samples collected 100 days apart. Following doxycycline treatment for Apl, multiple myeloma was diagnosed based upon a monoclonal gammopathy and splenic plasmacytosis, and the cat was treated with melphalan, chlorambucil and prednisolone. Apl DNA was not amplified from post-treatment blood samples and the hyperglobulinemia resolved temporarily following chemotherapy. Retrospective PCR analysis of stored DNA extracts identified CMh, Bk and Bh infections. Retrospective PCR for antigen receptor rearrangements (PARR) of splenic aspirates did not confirm B- or T-cell clonality. Co-infection with multiple vector-borne pathogens should be a diagnostic consideration in cats with chronic hypergammaglobulinemia, monoclonal gammopathy and splenic plasmacytosis.

A thermotolerant, Gram-strain-negative, non-spore-forming and strictly aerobic bacterium, designated GU51T, was isolated from Guhai hot spring in Jimsar county, Xinjiang province, north-west China. Each cell of strain GU51Tconsisted of an oval body and two symmetrical long (3–6 µm) prosthecae. The strain moved by polar flagellum. Oxidase and catalase were produced. Strain GU51Tgrew within the ranges of 37–65 °C (optimum 48–50 °C), 0.5–7.5 % (w/v) NaCl (optimum 2–3 %) and pH 6.0–9.0 (optimum pH 7.5). The major respiratory quinone detected was ubiquinone 10 (U-10) and the genomic DNA G+C content was 66.7±0.4 mol%. Major fatty acids (>5 %) were C16 : 0, C18 : 1ω7cand 11-methyl C18 : 1ω7c. The polar lipids consisted of diphosphatidylglycerol, five glycolipids, phosphatidylglycerol and an unknown phospholipid. Phylogenetic analysis showed the closest relatives of strain GU51Twere members of the genusParvularculawith 92.3 % 16S rRNA gene sequence similarity. On the basis of this polyphasic taxonomic characterization, it is suggested that strain GU51Trepresents a novel species of a new genus in the family ‘Parvularculaceae’, for which the nameAmphiplicatus metriothermophilusgen. nov., sp. nov. is proposed. The type strain of the type species is GU51T( = CGMCC 1.12710T = JCM 19779T).

ABSTRACT In Europe, human infections with “ Candidatus Neoehrlichia mikurensis” have mainly been restricted to immunocompromised patients. We report here the first cases of asymptomatic “ Ca . Neoehrlichia mikurensis” infection in immunocompetent humans (5/316 [1.6%] were infected). Due to the potential threats of infections with “ Ca . Neoehrlichia mikurensis” in healthy persons to the safety of the blood supply, further study of this phenomenon is required.

A new symptomatology was observed in celery (Apium graveolens) in Villena, Spain in 2008. Symptomatology included an abnormal amount of shoots per plant and curled stems. These vegetative disorders were associated with ‘Candidatus Liberibacter solanacearum’ and not with phytoplasmas. Samples from plant sap were immobilized on membranes based on the spot procedure and tested using a newly developed real-time polymerase chain reaction assay to detect ‘Ca. L. solanacearum’. Then, a test kit was developed and validated by intralaboratory assays with an accuracy of 100%. Bacterial-like cells with typical morphology of ‘Ca. Liberibacter’ were observed using electron microscopy in celery plant tissues. A fifth haplotype of ‘Ca. L. solanacearum’, named E, was identified in celery and in carrot after analyzing partial sequences of 16S and 50S ribosomal RNA genes. From our results, celery (family Apiaceae) can be listed as a new natural host of this emerging bacterium.