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Michel Drancourt - One of the best experts on this subject based on the ideXlab platform.
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RNA polymerase β-subunit-based phylogeny of Ehrlichia spp., Anaplasma spp., Neorickettsia spp. and Wolbachia pipientis
International Journal of Systematic and Evolutionary Microbiology, 2003Co-Authors: Anne-véronique Taillardat-bisch, Michel DrancourtAbstract:Sequence analysis of rpoB, the gene encoding the β-subunit of RNA polymerase, was used in a phylogenetic investigation of nine species from the genera Ehrlichia, Neorickettsia, Wolbachia and Anaplasma. The complete nucleotide sequences obtained for Anaplasma phagocytophilum (HGE agent), Ehrlichia chaffeensis, Neorickettsia sennetsu, Neorickettsia risticii, Anaplasma marginale and Wolbachia pipientis were amongst the longest rpoB sequences in GenBank and ranged from 4074 bp for N. sennetsu to 4311 bp for W. pipientis. Additional partial rpoB sequences were obtained for Ehrlichia canis, Ehrlichia ruminantium and Ehrlichia muris. Identical phylogenetic trees were inferred from multiple sequence alignments of the nucleotide sequences and the derived amino acid sequences using either distance, maximum-likelihood or parsimony methods. This study confirms the phylogeny previously inferred from sequence analyses of the 16S rRNA gene, groESL and gltA and allows the confirmation of four monophyletic clades. The rpoB nucleotide sequences were more variable than the 16S rRNA gene and groESL sequences at the species level.
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RNA polymerase beta-subunit-based phylogeny of Ehrlichia spp., Anaplasma spp., Neorickettsia spp. and Wolbachia pipientis.
International journal of systematic and evolutionary microbiology, 2003Co-Authors: Anne-véronique Taillardat-bisch, Michel DrancourtAbstract:Sequence analysis of rpoB, the gene encoding the beta-subunit of RNA polymerase, was used in a phylogenetic investigation of nine species from the genera Ehrlichia, Neorickettsia, Wolbachia and Anaplasma. The complete nucleotide sequences obtained for Anaplasma phagocytophilum (HGE agent), Ehrlichia chaffeensis, Neorickettsia sennetsu, Neorickettsia risticii, Anaplasma marginale and Wolbachia pipientis were amongst the longest rpoB sequences in GenBank and ranged from 4074 bp for N. sennetsu to 4311 bp for W. pipientis. Additional partial rpoB sequences were obtained for Ehrlichia canis, Ehrlichia ruminantium and Ehrlichia muris. Identical phylogenetic trees were inferred from multiple sequence alignments of the nucleotide sequences and the derived amino acid sequences using either distance, maximum-likelihood or parsimony methods. This study confirms the phylogeny previously inferred from sequence analyses of the 16S rRNA gene, groESL and gltA and allows the confirmation of four monophyletic clades. The rpoB nucleotide sequences were more variable than the 16S rRNA gene and groESL sequences at the species level.
Paul N. Newton - One of the best experts on this subject based on the ideXlab platform.
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Neorickettsia sennetsu as a Neglected Cause of Fever in South-East Asia
PLoS neglected tropical diseases, 2015Co-Authors: Sabine Dittrich, Weerawat Phuklia, Gareth D. H. Turner, Sayaphet Rattanavong, Vilada Chansamouth, Stephen J. Dumler, David J. P. Ferguson, Daniel H. Paris, Paul N. NewtonAbstract:Neorickettsia sennetsu infection is rarely recognized, with less than 100 globally reported patients over the last 50 years. The disease is thought to be contracted by eating raw fish, a staple of many South-East Asian cuisines. In 2009, the first patient with sennetsu was identified in the Lao PDR (Laos), raising the question as to how common this organism and related species are in patients presenting with fever. We investigated the frequency of N. sennetsu infection at hospitals in diverse areas of Laos. Consenting febrile hospital inpatients from central (Vientiane: n = 1,013), northern (Luang Namtha: n = 453) and southern (Salavan: n = 171) Laos were screened by PCR for N. sennetsu, if no previous positive direct diagnostic test was available. A PCR-restriction fragment length polymorphism assay was developed to differentiate between N. sennetsu, Ehrlichia chaffeensis and Anaplasma phagocytophilum. To allow more detailed studies of N. sennetsu, culture was successfully established using a reference strain (ATCC VR-367), identifying a canine-macrophage cell line (DH82) to be most suitable to visually identify infection. After screening, N. sennetsu was identified and sequence confirmed in four (4/1,637; 0.2%) Lao patients. Despite the previously identified high seroprevalence of N. sennetsu antibodies in the Lao population (~17%), acute N. sennetsu infection with sufficient clinical signs to prompt hospitalization appears to be rare. The reservoir, zoonotic cycle and pathogenicity of N. sennetsu remain unclear and require further investigations.
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sennetsu Neorickettsiosis: A Probable Fish-Borne Cause of Fever Rediscovered in Laos
2015Co-Authors: Address Correspondence To Paul Newton, Paul N. Newton, Jean-marc Rolain, Bouachanh Rasachak, Mayfong Mayxay, Khamtanh Vathanatham, Piseth Seng, Rattanaphone Phetsouvanh, Wellcome Trust-mahosot, Te ThammavongAbstract:Abstract. Neorickettsia sennetsu has been described from Japan and Malaysia, causing a largely forgotten infectious mononucleosis-like disease. Because it is believed to be contracted from eating raw fish, frequently consumed in the Lao PDR, we looked for evidence of N. sennetsu among Lao patients and fish. A buffy coat from 1 of 91 patients with undiffer-entiated fever was positive by 16S rRNA amplification and sequencing and real-time polymerase chain reactions (PCR) targeting two N. sennetsu genes. Lao blood donors and patients with fever, hepatitis, or jaundice ( N = 1,132) had a high prevalence (17%) of immunofluorescence assay IgG anti- N. sennetsu antibodies compared with 4 % and 0 % from febril
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sennetsu Neorickettsiosis: A Probable Fish-Borne Cause of Fever Rediscovered in Laos
American Journal of Tropical Medicine and Hygiene, 2009Co-Authors: Paul N. Newton, Jean-marc Rolain, Bouachanh Rasachak, Mayfong Mayxay, Khamtanh Vathanatham, Piseth Seng, Rattanaphone Phetsouvanh, Te Thammavong, Jamaayah Zahidi, Yupin SuputtamongkolAbstract:Neorickettsia sennetsu has been described from Japan and Malaysia, causing a largely forgotten infectious mononucleosis-like disease. Because it is believed to be contracted from eating raw fish, frequently consumed in the Lao PDR, we looked for evidence of N. sennetsu among Lao patients and fish. A buffy coat from 1 of 91 patients with undiffer- entiated fever was positive by 16S rRNA amplification and sequencing and real-time polymerase chain reactions (PCR) targeting two N. sennetsu genes. Lao blood donors and patients with fever, hepatitis, or jaundice ( N = 1,132) had a high prevalence (17%) of immunofluorescence assay IgG anti- N. sennetsu antibodies compared with 4% and 0% from febrile patients ( N = 848) in Thailand and Malaysia, respectively. We found N. sennetsu DNA by PCR, for the first time, in a fish ( Anabas testudineus ). These data suggest that sennetsu may be an under-recognized cause of fever and are consistent with the hypothesis that it may be contracted from eating raw fish. 1-6 The disease was char- acterized by fever, weakness, anorexia, generalized lymph- adenopathy, hepatosplenomegaly, and peripheral blood mononucleosis with atypical lymphocytes. The incubation period was ~14 days, and no fatalities were reported. The causative agent was isolated from patients' peripheral blood, lymph nodes, and bone marrow and subsequently renamed Ehrlichia sennetsu and most recently Neorickettsia sennetsu . 1-9 Neorickettsia are obligate intracellular bacteria closely related to Ehrlichia and Anaplasma and, unlike Rickettsia , grow in host membrane-lined cytoplasmic vacuoles. 5 The disease on Kyushu came to be known as sennetsu fever from the Japanese for infectious mononucleosis and was the first agent shown to cause this syndrome; Epstein-Barr virus as a cause was described 14 years later. The other described Neorickettsia spe- cies parasitize trematode flukes and mammals. N. helminthoeca infects flukes and canids, causing salmon poisoning disease in dogs in the Unites States, whereas N. risticii causes Poto- mac horse fever in North America and Europe and is prob- ably transmitted by trematodes of snails, insects, bats, and swallows. 5,9 sennetsu was shown to be transmissible to mice and then to humans in Japan. The feeding of raw gray mullet ( Mugil cephalus, a diadromous fish) to 96 people caused a sennetsu- like illness in 5% of subjects, and N. sennetsu was cultured from the blood of 4 of those who became ill, suggesting that the infection was linked to eating raw fish. Investigation of the epidemiology of sennetsu in Japan identified a closely related organism, the "SF agent," in Stellantchasmus falcatus fluke metacercaria in M. cephalus, but this agent is not known to cause human disease, and in non-human primates, oral inges- tion of the SF agent was not infectious. 3-6,10,11 Analysis of the 16S rRNA sequence of the SF agent suggests that it is most closely related to N. risticii and N. sennetsu . 10
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sennetsu Neorickettsiosis: A Probable Fish-Borne Cause of Fever Rediscovered in Laos
The American journal of tropical medicine and hygiene, 2009Co-Authors: Paul N. Newton, Jean-marc Rolain, Bouachanh Rasachak, Mayfong Mayxay, Khamtanh Vathanatham, Piseth Seng, Rattanaphone Phetsouvanh, Te Thammavong, Jamaayah Zahidi, Yupin SuputtamongkolAbstract:Neorickettsia sennetsu has been described from Japan and Malaysia, causing a largely forgotten infectious mononucleosis-like disease. Because it is believed to be contracted from eating raw fish, frequently consumed in the Lao PDR, we looked for evidence of N. sennetsu among Lao patients and fish. A buffy coat from 1 of 91 patients with undifferentiated fever was positive by 16S rRNA amplification and sequencing and real-time polymerase chain reactions (PCR) targeting two N. sennetsu genes. Lao blood donors and patients with fever, hepatitis, or jaundice (N = 1,132) had a high prevalence (17%) of immunofluorescence assay IgG anti-N. sennetsu antibodies compared with 4% and 0% from febrile patients (N = 848) in Thailand and Malaysia, respectively. We found N. sennetsu DNA by PCR, for the first time, in a fish (Anabas testudineus). These data suggest that sennetsu may be an under-recognized cause of fever and are consistent with the hypothesis that it may be contracted from eating raw fish.
Anne-véronique Taillardat-bisch - One of the best experts on this subject based on the ideXlab platform.
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RNA polymerase β-subunit-based phylogeny of Ehrlichia spp., Anaplasma spp., Neorickettsia spp. and Wolbachia pipientis
International Journal of Systematic and Evolutionary Microbiology, 2003Co-Authors: Anne-véronique Taillardat-bisch, Michel DrancourtAbstract:Sequence analysis of rpoB, the gene encoding the β-subunit of RNA polymerase, was used in a phylogenetic investigation of nine species from the genera Ehrlichia, Neorickettsia, Wolbachia and Anaplasma. The complete nucleotide sequences obtained for Anaplasma phagocytophilum (HGE agent), Ehrlichia chaffeensis, Neorickettsia sennetsu, Neorickettsia risticii, Anaplasma marginale and Wolbachia pipientis were amongst the longest rpoB sequences in GenBank and ranged from 4074 bp for N. sennetsu to 4311 bp for W. pipientis. Additional partial rpoB sequences were obtained for Ehrlichia canis, Ehrlichia ruminantium and Ehrlichia muris. Identical phylogenetic trees were inferred from multiple sequence alignments of the nucleotide sequences and the derived amino acid sequences using either distance, maximum-likelihood or parsimony methods. This study confirms the phylogeny previously inferred from sequence analyses of the 16S rRNA gene, groESL and gltA and allows the confirmation of four monophyletic clades. The rpoB nucleotide sequences were more variable than the 16S rRNA gene and groESL sequences at the species level.
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RNA polymerase beta-subunit-based phylogeny of Ehrlichia spp., Anaplasma spp., Neorickettsia spp. and Wolbachia pipientis.
International journal of systematic and evolutionary microbiology, 2003Co-Authors: Anne-véronique Taillardat-bisch, Michel DrancourtAbstract:Sequence analysis of rpoB, the gene encoding the beta-subunit of RNA polymerase, was used in a phylogenetic investigation of nine species from the genera Ehrlichia, Neorickettsia, Wolbachia and Anaplasma. The complete nucleotide sequences obtained for Anaplasma phagocytophilum (HGE agent), Ehrlichia chaffeensis, Neorickettsia sennetsu, Neorickettsia risticii, Anaplasma marginale and Wolbachia pipientis were amongst the longest rpoB sequences in GenBank and ranged from 4074 bp for N. sennetsu to 4311 bp for W. pipientis. Additional partial rpoB sequences were obtained for Ehrlichia canis, Ehrlichia ruminantium and Ehrlichia muris. Identical phylogenetic trees were inferred from multiple sequence alignments of the nucleotide sequences and the derived amino acid sequences using either distance, maximum-likelihood or parsimony methods. This study confirms the phylogeny previously inferred from sequence analyses of the 16S rRNA gene, groESL and gltA and allows the confirmation of four monophyletic clades. The rpoB nucleotide sequences were more variable than the 16S rRNA gene and groESL sequences at the species level.
Yupin Suputtamongkol - One of the best experts on this subject based on the ideXlab platform.
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sennetsu Neorickettsiosis: A Probable Fish-Borne Cause of Fever Rediscovered in Laos
American Journal of Tropical Medicine and Hygiene, 2009Co-Authors: Paul N. Newton, Jean-marc Rolain, Bouachanh Rasachak, Mayfong Mayxay, Khamtanh Vathanatham, Piseth Seng, Rattanaphone Phetsouvanh, Te Thammavong, Jamaayah Zahidi, Yupin SuputtamongkolAbstract:Neorickettsia sennetsu has been described from Japan and Malaysia, causing a largely forgotten infectious mononucleosis-like disease. Because it is believed to be contracted from eating raw fish, frequently consumed in the Lao PDR, we looked for evidence of N. sennetsu among Lao patients and fish. A buffy coat from 1 of 91 patients with undiffer- entiated fever was positive by 16S rRNA amplification and sequencing and real-time polymerase chain reactions (PCR) targeting two N. sennetsu genes. Lao blood donors and patients with fever, hepatitis, or jaundice ( N = 1,132) had a high prevalence (17%) of immunofluorescence assay IgG anti- N. sennetsu antibodies compared with 4% and 0% from febrile patients ( N = 848) in Thailand and Malaysia, respectively. We found N. sennetsu DNA by PCR, for the first time, in a fish ( Anabas testudineus ). These data suggest that sennetsu may be an under-recognized cause of fever and are consistent with the hypothesis that it may be contracted from eating raw fish. 1-6 The disease was char- acterized by fever, weakness, anorexia, generalized lymph- adenopathy, hepatosplenomegaly, and peripheral blood mononucleosis with atypical lymphocytes. The incubation period was ~14 days, and no fatalities were reported. The causative agent was isolated from patients' peripheral blood, lymph nodes, and bone marrow and subsequently renamed Ehrlichia sennetsu and most recently Neorickettsia sennetsu . 1-9 Neorickettsia are obligate intracellular bacteria closely related to Ehrlichia and Anaplasma and, unlike Rickettsia , grow in host membrane-lined cytoplasmic vacuoles. 5 The disease on Kyushu came to be known as sennetsu fever from the Japanese for infectious mononucleosis and was the first agent shown to cause this syndrome; Epstein-Barr virus as a cause was described 14 years later. The other described Neorickettsia spe- cies parasitize trematode flukes and mammals. N. helminthoeca infects flukes and canids, causing salmon poisoning disease in dogs in the Unites States, whereas N. risticii causes Poto- mac horse fever in North America and Europe and is prob- ably transmitted by trematodes of snails, insects, bats, and swallows. 5,9 sennetsu was shown to be transmissible to mice and then to humans in Japan. The feeding of raw gray mullet ( Mugil cephalus, a diadromous fish) to 96 people caused a sennetsu- like illness in 5% of subjects, and N. sennetsu was cultured from the blood of 4 of those who became ill, suggesting that the infection was linked to eating raw fish. Investigation of the epidemiology of sennetsu in Japan identified a closely related organism, the "SF agent," in Stellantchasmus falcatus fluke metacercaria in M. cephalus, but this agent is not known to cause human disease, and in non-human primates, oral inges- tion of the SF agent was not infectious. 3-6,10,11 Analysis of the 16S rRNA sequence of the SF agent suggests that it is most closely related to N. risticii and N. sennetsu . 10
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sennetsu Neorickettsiosis: A Probable Fish-Borne Cause of Fever Rediscovered in Laos
The American journal of tropical medicine and hygiene, 2009Co-Authors: Paul N. Newton, Jean-marc Rolain, Bouachanh Rasachak, Mayfong Mayxay, Khamtanh Vathanatham, Piseth Seng, Rattanaphone Phetsouvanh, Te Thammavong, Jamaayah Zahidi, Yupin SuputtamongkolAbstract:Neorickettsia sennetsu has been described from Japan and Malaysia, causing a largely forgotten infectious mononucleosis-like disease. Because it is believed to be contracted from eating raw fish, frequently consumed in the Lao PDR, we looked for evidence of N. sennetsu among Lao patients and fish. A buffy coat from 1 of 91 patients with undifferentiated fever was positive by 16S rRNA amplification and sequencing and real-time polymerase chain reactions (PCR) targeting two N. sennetsu genes. Lao blood donors and patients with fever, hepatitis, or jaundice (N = 1,132) had a high prevalence (17%) of immunofluorescence assay IgG anti-N. sennetsu antibodies compared with 4% and 0% from febrile patients (N = 848) in Thailand and Malaysia, respectively. We found N. sennetsu DNA by PCR, for the first time, in a fish (Anabas testudineus). These data suggest that sennetsu may be an under-recognized cause of fever and are consistent with the hypothesis that it may be contracted from eating raw fish.
Yasuko Rikihisa - One of the best experts on this subject based on the ideXlab platform.
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Proteomic Analysis of Neorickettsia sennetsu Surface-Exposed Proteins and Porin Activity of the Major Surface Protein P51
Journal of bacteriology, 2010Co-Authors: Kathryn E. Gibson, Yumi Kumagai, Yasuko RikihisaAbstract:ABSTRACT Neorickettsia sennetsu is an obligate intracellular bacterium of monocytes and macrophages and is the etiologic agent of human sennetsu neorickettsiosis. Neorickettsia proteins expressed in mammalian host cells, including the surface proteins of Neorickettsia spp., have not been defined. In this paper, we isolated surface-exposed proteins from N. sennetsu by biotin surface labeling followed by streptavidin-affinity chromatography. Forty-two of the total of 936 (4.5%) N. sennetsu open reading frames (ORFs) were detected by liquid chromatography-tandem mass spectrometry (LC/MS/MS), including six hypothetical proteins. Among the major proteins identified were the two major β-barrel proteins: the 51-kDa antigen (P51) and Neorickettsia surface protein 3 (Nsp3). Immunofluorescence labeling not only confirmed surface exposure of these proteins but also showed rosary-like circumferential labeling with anti-P51 for the majority of bacteria and polar to diffuse punctate labeling with anti-Nsp3 for a minority of bacteria. We found that the isolated outer membrane of N. sennetsu had porin activity, as measured by a proteoliposome swelling assay. This activity allowed the diffusion of l-glutamine, the monosaccharides arabinose and glucose, and the tetrasaccharide stachyose, which could be inhibited with anti-P51 antibody. We purified native P51 and Nsp3 under nondenaturing conditions. When reconstituted into proteoliposomes, purified P51, but not Nsp3, exhibited prominent porin activity. This the first proteomic study of a Neorickettsia sp. showing new sets of proteins evolved as major surface proteins for Neorickettsia and the first identification of a porin for the genus Neorickettsia.
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Analysis of p51, groESL, and the Major Antigen P51 in Various Species of Neorickettsia, an Obligatory Intracellular Bacterium That Infects Trematodes and Mammals
Journal of clinical microbiology, 2004Co-Authors: Yasuko Rikihisa, Chunbin Zhang, Manuel Kanter, Zhihui Cheng, Norio Ohashi, Takeo FukudaAbstract:The p51 gene that encodes the major antigenic 51-kDa protein in Neorickettsia risticii was identified in strains of Neorickettsia sennetsu and the Stellantchasmus falcatus agent but not in Neorickettsia helminthoeca, suggesting that p51-based diagnosis would be useful to distinguish among them. groESL sequencing results delineated the phylogenic relationships among Neorickettsia spp.