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Selwyn Arlington Headley - One of the best experts on this subject based on the ideXlab platform.
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Neorickettsia helminthoeca associated lymphoid, enteric, and pulmonary lesions in dogs from Southern Brazil: An immunohistochemical study
Transboundary and Emerging Diseases, 2019Co-Authors: Selwyn Arlington Headley, Mariana De Mello Zanim Michelazzo, Nayara Emily Viana, Ana Aparecida Correa Xavier, Cícero Júlio Silva Costa, Felipe Pinho, Marcelo Diniz Dos SantosAbstract:Neorickettsia helminthoeca (NH), the agent of salmon poisoning disease or canine neorickettiosis (CN), is a bacterial endosymbiont of the nematode Nanophyetus salmincola, and infections are spreading among specific fish-eating mammalians. This article describes the pathologic and immunohistochemical findings associated with spontaneous NH-induced infections in dogs from Southern Brazil. The principal pathologic findings were hypertrophy of Peyer patches and lymphadenopathy with lymphocytic proliferation, chronic interstitial pneumonia, and chronic enteritis associated with positive intralesional immunoreactivity to antigens of NH within macrophages and histiocytes. Positive immunoreactivity against canine parvovirus-2 (CPV-2) or/and canine distemper virus was not detected in the evaluated intestinal segments or in the samples from the cerebellum and lungs, respectively, from the dogs evaluated. These findings demonstrated that NH was involved in the enteric, pulmonary, and lymphoid lesions herein described, and provide additional information to confirm the occurrence of this bacterial endosymbiont within this geographical location. It is proposed that chronic pneumonia should be considered as a pathologic manifestation of NH-induced infections. Additionally, our results show that the occurrences of CN seem to be underdiagnosed in Southern Brazil due to the confusion with the incidence of CPV-2.
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IMMUNOHISTOCHEMICAL AND MOLECULAR EVIDENCE OF PUTATIVE Neorickettsia INFECTION IN COATIS ( NASUA NASUA) FROM SOUTHERN BRAZIL.
Journal of zoo and wildlife medicine : official publication of the American Association of Zoo Veterinarians, 2018Co-Authors: Selwyn Arlington Headley, Wanderlei De Moraes, Zalmir Silvino Cubas, Thalita Evani Silva De Oliveira, Mariana De Mello Zanim Michelazzo, Juliana Torres Tomazi Fritzen, Amauri Alcindo Alfieri, Odilon VidottoAbstract:Abstract The pathologic, molecular, and immunohistochemical findings associated with Neorickettsia helminthoeca are described in coatis (Nasua nasua). Tissue sections (small intestine, lungs, kidney, liver, and spleen) of coatis (n = 3) that died at the Bela Vista Biological Refuge, Foz do Iguacu, Parana, southern Brazil were routinely processed from histopathology. Selected formalin-fixed paraffin-embedded (FFPE) tissue sections of the small intestine, lungs, and spleen were used in an immunohistochemical (IHC) assay designed to identify the antigens of N. helminthoeca. Additionally, FFPE tissue sections of the small intestine were used to demonstrate antigens of canine parvovirus-2 (CPV-2) by IHC. Histopathology revealed chronic enteritis in all coatis. Parasitic enteritis was diagnosed in two coatis; one of these contained examples of a trematode within the lumen of the small intestine and the ovum of a trematode encysted in the intestinal mucosa. Other significant pathologic findings included intersti...
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Neorickettsia helminthoeca and salmon poisoning disease: A review
Veterinary journal (London England : 1997), 2009Co-Authors: Selwyn Arlington Headley, Odilon Vidotto, Diana G. Scorpio, J. Stephen DumlerAbstract:Neorickettsia helminthoeca is an obligate intra-cytoplasmic bacterium that causes salmon poisoning disease (SPD), an acute, febrile, fatal disease of dogs. The complex life-cycle of this pathogen involves stages in an intestinal fluke (Nanophyetus salmincola), a river snail (Oxytrema silicula), in fish, and in fish-eating mammals. This complexity has created confusion with respect to the various bacterial and parasitic infections associated with the disease and its significance in dogs in specific geographical locations has likely to have previously been under-estimated. This paper addresses the history, taxonomy, microbiology of N. helminthoeca and summarises the pathogenesis, clinical signs and pathological features associated with infection. Furthermore, the biological cycles, treatment, control, and both public and veterinary health impacts associated with this pathogen and the intestinal fluke N. salmincola are discussed.
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Neorickettsia helminthoeca in Brazilian dogs: a cytopathological, histopathological and immunohistochemical study.
Clinical Microbiology and Infection, 2009Co-Authors: Selwyn Arlington Headley, Ana Paula Frederico Rodrigues Loureiro Bracarense, Odilon Vidotto, Diana G. Scorpio, Nicole C. Barat, Flora Satiko Kano, Katia Tamekuni, J. Stephen DumlerAbstract:Pathology, The Johns Hopkins University School of Medicine, Baltimore, MD,USAINTRODUCTIONNeorickettsia helminthoeca is an intracellular bacte-rium of reticuloendothelial cells of dogs thatcauses salmon poisoning disease (SPD), whichwas considered endemic only to specific geo-2graphical locations of North America [1–3].However, 20 mature dogs demonstrated lesionsconsistent with this infection in Southern Braziland intracytoplasmic and intralesional neorickett-sial bodies were identified within reticuloendo-thelial cells by Giemsa stain [4]. Additionally, bymolecular biology methods, it was shown that themesenteric lymph node of one dog containedDNA that was similar to N. helminthoeca as knownin the USA [5].This article describes the cytological, histopath-ological and immunohistochemical findings asso-ciated with N. helminthoeca in additional casesfrom Brazil.MATERIALS AND METHODS
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Neorickettsia helminthoeca in dog brazil
Emerging Infectious Diseases, 2006Co-Authors: Selwyn Arlington Headley, Odilon Vidotto, Diana G. Scorpio, Nicole C. Barat, Stephen J. DumlerAbstract:To the Editor: Neorickettsia helminthoeca causes salmon poisoning disease (SPD) in canids. SPD has been described only in the United States and the northwestern Pacific region of Canada (1). This report complements previous pathologic findings (2) and identifies SPD beyond the known disease-endemic region. From 2001 to 2005, 20 dogs (5 mongrels and 15 beagles) showed pathologic lesions consistent with SPD. All beagles were born in coastal Florianopolis, Santa Catarina, Brazil, and later transferred to Maringa, Parana, Brazil, for the last 3–4 years of life. Lymph nodes, spleen, liver, and intestines from 10 beagles were aseptically obtained at necropsy in Maringa and frozen at -20°C until used at the Johns Hopkins Medical Institutions in Baltimore, Maryland. Genomic DNA was extracted from frozen tissues with QIAamp DNA Mini Kits (Qiagen, Valencia, CA, USA). DNA from N. helminthoeca and Anaplasma phagocytophilum was used as a positive control. Nuclease-free water was used as a negative control. We used gene-specific primers for Neorickettsia spp. 16S rRNA (rrs) (NeoSH-F; 5´-TAGGCCCGCGTTAGATTAGCTTGT-3´ and NeoSH-R; 5´-TACAACCCAAGGGCCTTCATCACT-3´) and N. helminthoeca RNA polymerase β-subunit (rpoB) (NH-rpoB-F: 5´-TGTCTTCGAAGGCCCAAAGACAGA-3´ and NH-rpoB-R: 5´-AGAACCGATAGAGCGGGCATGAAT-3´) (3) and heat-shock protein groESL (NH-groESL-F: 5´-AGGCTACTTCGCAGGCAAATGAGA-3´ and NH-groESL-R: 5´-CACGCTTCATTCCGCCCTTTAACT-3´) (4,5). Citrate synthase (gltA) gene primers (6) were also used. Two PCRs were conducted to maximize sensitivity. Specificity of N. helminthoeca–specific primers was shown by amplification studies of genomic DNA of A. phagocytophilum, Ehrlichia chaffeensis, E. canis, N. risticii, N. sennetsu, and N. helminthoeca. All amplicons were separated by electrophoresis in 1% agarose gels and purified before cloning (pGEM-T and pGEM-T Easy Vector Systems, Promega, Madison, WI, USA) and sequencing. The Maringa sequences obtained were compared with those in GenBank by using BLAST (http://www.ncbi.nlm.nih.gov/BLAST). Phylogenetic trees, sequence alignments, and identity tables were created by using Vector NTI Advance10 Software (Invitrogen, Carlsbad, CA, USA). GenBank accession numbers of Anaplasmataceae and their phylogenetic relationships are shown in the Figure. Figure Neighbor-joining phylogenetic trees of the 16S rRNA (rrs), RNA polymerase β-subunit (rpoB), and heat-shock protein (groESL) gene sequences of Anaplasmataceae families. Trees were constructed with Vector NTI Advance10 Software (Invitrogen, Carlsbad, ... Two dogs (N40–05, mesenteric lymph node, Maringa 1 and N20–04, Peyer's patch, Maringa 2) contained Neorickettsia spp. rrs, rpoB, or groESL genes. Both samples produced partial sequences for Neorickettsia spp. rrs gene; a similarity of 99% was observed for the 2 Maringa dog rrs sequences with N. sennetsu, N. risticii, and the Stellantchasmus falcatus (SF) agent. However, N. helminthoeca rpoB and groESL partial sequences were obtained only from dog 1. DNA identities of 100%, 82%, and 81% were observed between Maringa dog 1 sequences and N. helminthoeca, N. risticii, and N. sennetsu for the rpoB genes, respectively. All dogs were negative when tested with gltA gene primers. We observed 100% identity between the Maringa dog 1 sequence and N. helminthoeca groESL gene sequences. Similarities of 84%, 80%, and 79% were observed with N. sennetsu, the SF agent, and N. risticii, respectively. All positive controls showed bands of appropriate sizes, whereas negative controls yielded no products, confirming lack of amplicon contamination. This study demonstrates that 2 dogs from Maringa, Brazil, with pathologic lesions consistent with SPD (7) were infected with a Neorickettsia sp. The partial sequences from dog 1 were identical to N. helminthoeca rrs, groESL, and rpoB genes, confirming infection with this organism (2). To our knowledge, this is the first confirmed description of this organism beyond the known geographic area of SPD. The organism identified in Brazil has been named N. helminthoeca Maringa strain. Because of difficulty in recovering DNA from samples, need for a highly efficient PCR targeting small DNA regions, and limited sensitivity of the amplifications, sequences obtained for N. helminthoeca Maringa dog 1 (112 bp for rrs, 92 bp for groESL, 143 bp for rpoB) were short compared with those in GenBank (rrs 1,453 bp, groESL 1,914 bp, rpoB, 464 bp). Efficiency and sensitivity of targeting small DNA regions was necessary since storage and shipment of frozen samples were not optimal. Small DNA sequences are often suboptimal for delineation of phylogenetic relationships. Bootstrapping analyses showed poor resolution (<380/1,000 iterations) below the genus level for the short rrs region examined. However, both the short rpoB and groESL regions examined had high bootstrap values (941/1,000 and 995/1,000 iterations, respectively). This finding allowed differentiation of N. helminthoeca and the Brazilian dog strain from N. sennetsu, N. risticii, and other related Anaplasmataceae and provided a high degree of confidence in the identification. More work is being implemented to obtain longer sequences to confirm and extend these genotypic comparisons. We propose further study to isolate the pathogen from other dogs for comparative biologic analyses. Although SPD is caused by N. helminthoeca, infections by other Neorickettsia spp., including N. risticii (Potomac horse fever) and N. sennetsu (sennetsu fever), illustrate the potential of these widely distributed species to infect and cause disease in mammals and humans. Detection of N. helminthoeca in Brazilian dogs extends the range of this species and warrants a broad search for infections and spectrum of disease of Neorickettsia in animals and humans.
Odilon Vidotto - One of the best experts on this subject based on the ideXlab platform.
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IMMUNOHISTOCHEMICAL AND MOLECULAR EVIDENCE OF PUTATIVE Neorickettsia INFECTION IN COATIS ( NASUA NASUA) FROM SOUTHERN BRAZIL.
Journal of zoo and wildlife medicine : official publication of the American Association of Zoo Veterinarians, 2018Co-Authors: Selwyn Arlington Headley, Wanderlei De Moraes, Zalmir Silvino Cubas, Thalita Evani Silva De Oliveira, Mariana De Mello Zanim Michelazzo, Juliana Torres Tomazi Fritzen, Amauri Alcindo Alfieri, Odilon VidottoAbstract:Abstract The pathologic, molecular, and immunohistochemical findings associated with Neorickettsia helminthoeca are described in coatis (Nasua nasua). Tissue sections (small intestine, lungs, kidney, liver, and spleen) of coatis (n = 3) that died at the Bela Vista Biological Refuge, Foz do Iguacu, Parana, southern Brazil were routinely processed from histopathology. Selected formalin-fixed paraffin-embedded (FFPE) tissue sections of the small intestine, lungs, and spleen were used in an immunohistochemical (IHC) assay designed to identify the antigens of N. helminthoeca. Additionally, FFPE tissue sections of the small intestine were used to demonstrate antigens of canine parvovirus-2 (CPV-2) by IHC. Histopathology revealed chronic enteritis in all coatis. Parasitic enteritis was diagnosed in two coatis; one of these contained examples of a trematode within the lumen of the small intestine and the ovum of a trematode encysted in the intestinal mucosa. Other significant pathologic findings included intersti...
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Neorickettsia helminthoeca and salmon poisoning disease: A review
Veterinary journal (London England : 1997), 2009Co-Authors: Selwyn Arlington Headley, Odilon Vidotto, Diana G. Scorpio, J. Stephen DumlerAbstract:Neorickettsia helminthoeca is an obligate intra-cytoplasmic bacterium that causes salmon poisoning disease (SPD), an acute, febrile, fatal disease of dogs. The complex life-cycle of this pathogen involves stages in an intestinal fluke (Nanophyetus salmincola), a river snail (Oxytrema silicula), in fish, and in fish-eating mammals. This complexity has created confusion with respect to the various bacterial and parasitic infections associated with the disease and its significance in dogs in specific geographical locations has likely to have previously been under-estimated. This paper addresses the history, taxonomy, microbiology of N. helminthoeca and summarises the pathogenesis, clinical signs and pathological features associated with infection. Furthermore, the biological cycles, treatment, control, and both public and veterinary health impacts associated with this pathogen and the intestinal fluke N. salmincola are discussed.
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Neorickettsia helminthoeca in Brazilian dogs: a cytopathological, histopathological and immunohistochemical study.
Clinical Microbiology and Infection, 2009Co-Authors: Selwyn Arlington Headley, Ana Paula Frederico Rodrigues Loureiro Bracarense, Odilon Vidotto, Diana G. Scorpio, Nicole C. Barat, Flora Satiko Kano, Katia Tamekuni, J. Stephen DumlerAbstract:Pathology, The Johns Hopkins University School of Medicine, Baltimore, MD,USAINTRODUCTIONNeorickettsia helminthoeca is an intracellular bacte-rium of reticuloendothelial cells of dogs thatcauses salmon poisoning disease (SPD), whichwas considered endemic only to specific geo-2graphical locations of North America [1–3].However, 20 mature dogs demonstrated lesionsconsistent with this infection in Southern Braziland intracytoplasmic and intralesional neorickett-sial bodies were identified within reticuloendo-thelial cells by Giemsa stain [4]. Additionally, bymolecular biology methods, it was shown that themesenteric lymph node of one dog containedDNA that was similar to N. helminthoeca as knownin the USA [5].This article describes the cytological, histopath-ological and immunohistochemical findings asso-ciated with N. helminthoeca in additional casesfrom Brazil.MATERIALS AND METHODS
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Neorickettsia helminthoeca in dog brazil
Emerging Infectious Diseases, 2006Co-Authors: Selwyn Arlington Headley, Odilon Vidotto, Diana G. Scorpio, Nicole C. Barat, Stephen J. DumlerAbstract:To the Editor: Neorickettsia helminthoeca causes salmon poisoning disease (SPD) in canids. SPD has been described only in the United States and the northwestern Pacific region of Canada (1). This report complements previous pathologic findings (2) and identifies SPD beyond the known disease-endemic region. From 2001 to 2005, 20 dogs (5 mongrels and 15 beagles) showed pathologic lesions consistent with SPD. All beagles were born in coastal Florianopolis, Santa Catarina, Brazil, and later transferred to Maringa, Parana, Brazil, for the last 3–4 years of life. Lymph nodes, spleen, liver, and intestines from 10 beagles were aseptically obtained at necropsy in Maringa and frozen at -20°C until used at the Johns Hopkins Medical Institutions in Baltimore, Maryland. Genomic DNA was extracted from frozen tissues with QIAamp DNA Mini Kits (Qiagen, Valencia, CA, USA). DNA from N. helminthoeca and Anaplasma phagocytophilum was used as a positive control. Nuclease-free water was used as a negative control. We used gene-specific primers for Neorickettsia spp. 16S rRNA (rrs) (NeoSH-F; 5´-TAGGCCCGCGTTAGATTAGCTTGT-3´ and NeoSH-R; 5´-TACAACCCAAGGGCCTTCATCACT-3´) and N. helminthoeca RNA polymerase β-subunit (rpoB) (NH-rpoB-F: 5´-TGTCTTCGAAGGCCCAAAGACAGA-3´ and NH-rpoB-R: 5´-AGAACCGATAGAGCGGGCATGAAT-3´) (3) and heat-shock protein groESL (NH-groESL-F: 5´-AGGCTACTTCGCAGGCAAATGAGA-3´ and NH-groESL-R: 5´-CACGCTTCATTCCGCCCTTTAACT-3´) (4,5). Citrate synthase (gltA) gene primers (6) were also used. Two PCRs were conducted to maximize sensitivity. Specificity of N. helminthoeca–specific primers was shown by amplification studies of genomic DNA of A. phagocytophilum, Ehrlichia chaffeensis, E. canis, N. risticii, N. sennetsu, and N. helminthoeca. All amplicons were separated by electrophoresis in 1% agarose gels and purified before cloning (pGEM-T and pGEM-T Easy Vector Systems, Promega, Madison, WI, USA) and sequencing. The Maringa sequences obtained were compared with those in GenBank by using BLAST (http://www.ncbi.nlm.nih.gov/BLAST). Phylogenetic trees, sequence alignments, and identity tables were created by using Vector NTI Advance10 Software (Invitrogen, Carlsbad, CA, USA). GenBank accession numbers of Anaplasmataceae and their phylogenetic relationships are shown in the Figure. Figure Neighbor-joining phylogenetic trees of the 16S rRNA (rrs), RNA polymerase β-subunit (rpoB), and heat-shock protein (groESL) gene sequences of Anaplasmataceae families. Trees were constructed with Vector NTI Advance10 Software (Invitrogen, Carlsbad, ... Two dogs (N40–05, mesenteric lymph node, Maringa 1 and N20–04, Peyer's patch, Maringa 2) contained Neorickettsia spp. rrs, rpoB, or groESL genes. Both samples produced partial sequences for Neorickettsia spp. rrs gene; a similarity of 99% was observed for the 2 Maringa dog rrs sequences with N. sennetsu, N. risticii, and the Stellantchasmus falcatus (SF) agent. However, N. helminthoeca rpoB and groESL partial sequences were obtained only from dog 1. DNA identities of 100%, 82%, and 81% were observed between Maringa dog 1 sequences and N. helminthoeca, N. risticii, and N. sennetsu for the rpoB genes, respectively. All dogs were negative when tested with gltA gene primers. We observed 100% identity between the Maringa dog 1 sequence and N. helminthoeca groESL gene sequences. Similarities of 84%, 80%, and 79% were observed with N. sennetsu, the SF agent, and N. risticii, respectively. All positive controls showed bands of appropriate sizes, whereas negative controls yielded no products, confirming lack of amplicon contamination. This study demonstrates that 2 dogs from Maringa, Brazil, with pathologic lesions consistent with SPD (7) were infected with a Neorickettsia sp. The partial sequences from dog 1 were identical to N. helminthoeca rrs, groESL, and rpoB genes, confirming infection with this organism (2). To our knowledge, this is the first confirmed description of this organism beyond the known geographic area of SPD. The organism identified in Brazil has been named N. helminthoeca Maringa strain. Because of difficulty in recovering DNA from samples, need for a highly efficient PCR targeting small DNA regions, and limited sensitivity of the amplifications, sequences obtained for N. helminthoeca Maringa dog 1 (112 bp for rrs, 92 bp for groESL, 143 bp for rpoB) were short compared with those in GenBank (rrs 1,453 bp, groESL 1,914 bp, rpoB, 464 bp). Efficiency and sensitivity of targeting small DNA regions was necessary since storage and shipment of frozen samples were not optimal. Small DNA sequences are often suboptimal for delineation of phylogenetic relationships. Bootstrapping analyses showed poor resolution (<380/1,000 iterations) below the genus level for the short rrs region examined. However, both the short rpoB and groESL regions examined had high bootstrap values (941/1,000 and 995/1,000 iterations, respectively). This finding allowed differentiation of N. helminthoeca and the Brazilian dog strain from N. sennetsu, N. risticii, and other related Anaplasmataceae and provided a high degree of confidence in the identification. More work is being implemented to obtain longer sequences to confirm and extend these genotypic comparisons. We propose further study to isolate the pathogen from other dogs for comparative biologic analyses. Although SPD is caused by N. helminthoeca, infections by other Neorickettsia spp., including N. risticii (Potomac horse fever) and N. sennetsu (sennetsu fever), illustrate the potential of these widely distributed species to infect and cause disease in mammals and humans. Detection of N. helminthoeca in Brazilian dogs extends the range of this species and warrants a broad search for infections and spectrum of disease of Neorickettsia in animals and humans.
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Suspected cases of Neorickettsia-like organisms in Brazilian dogs.
Annals of the New York Academy of Sciences, 2004Co-Authors: Selwyn Arlington Headley, Odilon Vidotto, Diana G. Scorpio, J. Stephen Dumler, Joseph L. MankowskiAbstract:Preliminary findings of gross and histopathological lesions consistent with salmon poisoning disease in 10 dogs from southern Brazil are described. Lesions were restricted to the spleen, lymph nodes, and intestinal lymphoid tissues. Grossly, there was marked hyperplasia of mesenteric lymph nodes and Peyer's patches. Microscopic alterations were characterized by diffuse hyperplasia of intestinal lymphoid tissues and Peyer's patches. Intracytoplasmic organisms consistent with Neorickettsia helminthoeca were demonstrated by Giemsa stain in reticuloendothelial cells of the intestine, spleen, Peyer's patches, and lymph nodes. We have named this organism Neorickettsia helminthoeca-like because of its marked similarity with the agent described in the United States.
J. Stephen Dumler - One of the best experts on this subject based on the ideXlab platform.
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Neorickettsia helminthoeca and salmon poisoning disease: A review
Veterinary journal (London England : 1997), 2009Co-Authors: Selwyn Arlington Headley, Odilon Vidotto, Diana G. Scorpio, J. Stephen DumlerAbstract:Neorickettsia helminthoeca is an obligate intra-cytoplasmic bacterium that causes salmon poisoning disease (SPD), an acute, febrile, fatal disease of dogs. The complex life-cycle of this pathogen involves stages in an intestinal fluke (Nanophyetus salmincola), a river snail (Oxytrema silicula), in fish, and in fish-eating mammals. This complexity has created confusion with respect to the various bacterial and parasitic infections associated with the disease and its significance in dogs in specific geographical locations has likely to have previously been under-estimated. This paper addresses the history, taxonomy, microbiology of N. helminthoeca and summarises the pathogenesis, clinical signs and pathological features associated with infection. Furthermore, the biological cycles, treatment, control, and both public and veterinary health impacts associated with this pathogen and the intestinal fluke N. salmincola are discussed.
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Neorickettsia helminthoeca in Brazilian dogs: a cytopathological, histopathological and immunohistochemical study.
Clinical Microbiology and Infection, 2009Co-Authors: Selwyn Arlington Headley, Ana Paula Frederico Rodrigues Loureiro Bracarense, Odilon Vidotto, Diana G. Scorpio, Nicole C. Barat, Flora Satiko Kano, Katia Tamekuni, J. Stephen DumlerAbstract:Pathology, The Johns Hopkins University School of Medicine, Baltimore, MD,USAINTRODUCTIONNeorickettsia helminthoeca is an intracellular bacte-rium of reticuloendothelial cells of dogs thatcauses salmon poisoning disease (SPD), whichwas considered endemic only to specific geo-2graphical locations of North America [1–3].However, 20 mature dogs demonstrated lesionsconsistent with this infection in Southern Braziland intracytoplasmic and intralesional neorickett-sial bodies were identified within reticuloendo-thelial cells by Giemsa stain [4]. Additionally, bymolecular biology methods, it was shown that themesenteric lymph node of one dog containedDNA that was similar to N. helminthoeca as knownin the USA [5].This article describes the cytological, histopath-ological and immunohistochemical findings asso-ciated with N. helminthoeca in additional casesfrom Brazil.MATERIALS AND METHODS
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Suspected cases of Neorickettsia-like organisms in Brazilian dogs.
Annals of the New York Academy of Sciences, 2004Co-Authors: Selwyn Arlington Headley, Odilon Vidotto, Diana G. Scorpio, J. Stephen Dumler, Joseph L. MankowskiAbstract:Preliminary findings of gross and histopathological lesions consistent with salmon poisoning disease in 10 dogs from southern Brazil are described. Lesions were restricted to the spleen, lymph nodes, and intestinal lymphoid tissues. Grossly, there was marked hyperplasia of mesenteric lymph nodes and Peyer's patches. Microscopic alterations were characterized by diffuse hyperplasia of intestinal lymphoid tissues and Peyer's patches. Intracytoplasmic organisms consistent with Neorickettsia helminthoeca were demonstrated by Giemsa stain in reticuloendothelial cells of the intestine, spleen, Peyer's patches, and lymph nodes. We have named this organism Neorickettsia helminthoeca-like because of its marked similarity with the agent described in the United States.
Diana G. Scorpio - One of the best experts on this subject based on the ideXlab platform.
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Neorickettsia helminthoeca and salmon poisoning disease: A review
Veterinary journal (London England : 1997), 2009Co-Authors: Selwyn Arlington Headley, Odilon Vidotto, Diana G. Scorpio, J. Stephen DumlerAbstract:Neorickettsia helminthoeca is an obligate intra-cytoplasmic bacterium that causes salmon poisoning disease (SPD), an acute, febrile, fatal disease of dogs. The complex life-cycle of this pathogen involves stages in an intestinal fluke (Nanophyetus salmincola), a river snail (Oxytrema silicula), in fish, and in fish-eating mammals. This complexity has created confusion with respect to the various bacterial and parasitic infections associated with the disease and its significance in dogs in specific geographical locations has likely to have previously been under-estimated. This paper addresses the history, taxonomy, microbiology of N. helminthoeca and summarises the pathogenesis, clinical signs and pathological features associated with infection. Furthermore, the biological cycles, treatment, control, and both public and veterinary health impacts associated with this pathogen and the intestinal fluke N. salmincola are discussed.
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Neorickettsia helminthoeca in Brazilian dogs: a cytopathological, histopathological and immunohistochemical study.
Clinical Microbiology and Infection, 2009Co-Authors: Selwyn Arlington Headley, Ana Paula Frederico Rodrigues Loureiro Bracarense, Odilon Vidotto, Diana G. Scorpio, Nicole C. Barat, Flora Satiko Kano, Katia Tamekuni, J. Stephen DumlerAbstract:Pathology, The Johns Hopkins University School of Medicine, Baltimore, MD,USAINTRODUCTIONNeorickettsia helminthoeca is an intracellular bacte-rium of reticuloendothelial cells of dogs thatcauses salmon poisoning disease (SPD), whichwas considered endemic only to specific geo-2graphical locations of North America [1–3].However, 20 mature dogs demonstrated lesionsconsistent with this infection in Southern Braziland intracytoplasmic and intralesional neorickett-sial bodies were identified within reticuloendo-thelial cells by Giemsa stain [4]. Additionally, bymolecular biology methods, it was shown that themesenteric lymph node of one dog containedDNA that was similar to N. helminthoeca as knownin the USA [5].This article describes the cytological, histopath-ological and immunohistochemical findings asso-ciated with N. helminthoeca in additional casesfrom Brazil.MATERIALS AND METHODS
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Neorickettsia helminthoeca in dog brazil
Emerging Infectious Diseases, 2006Co-Authors: Selwyn Arlington Headley, Odilon Vidotto, Diana G. Scorpio, Nicole C. Barat, Stephen J. DumlerAbstract:To the Editor: Neorickettsia helminthoeca causes salmon poisoning disease (SPD) in canids. SPD has been described only in the United States and the northwestern Pacific region of Canada (1). This report complements previous pathologic findings (2) and identifies SPD beyond the known disease-endemic region. From 2001 to 2005, 20 dogs (5 mongrels and 15 beagles) showed pathologic lesions consistent with SPD. All beagles were born in coastal Florianopolis, Santa Catarina, Brazil, and later transferred to Maringa, Parana, Brazil, for the last 3–4 years of life. Lymph nodes, spleen, liver, and intestines from 10 beagles were aseptically obtained at necropsy in Maringa and frozen at -20°C until used at the Johns Hopkins Medical Institutions in Baltimore, Maryland. Genomic DNA was extracted from frozen tissues with QIAamp DNA Mini Kits (Qiagen, Valencia, CA, USA). DNA from N. helminthoeca and Anaplasma phagocytophilum was used as a positive control. Nuclease-free water was used as a negative control. We used gene-specific primers for Neorickettsia spp. 16S rRNA (rrs) (NeoSH-F; 5´-TAGGCCCGCGTTAGATTAGCTTGT-3´ and NeoSH-R; 5´-TACAACCCAAGGGCCTTCATCACT-3´) and N. helminthoeca RNA polymerase β-subunit (rpoB) (NH-rpoB-F: 5´-TGTCTTCGAAGGCCCAAAGACAGA-3´ and NH-rpoB-R: 5´-AGAACCGATAGAGCGGGCATGAAT-3´) (3) and heat-shock protein groESL (NH-groESL-F: 5´-AGGCTACTTCGCAGGCAAATGAGA-3´ and NH-groESL-R: 5´-CACGCTTCATTCCGCCCTTTAACT-3´) (4,5). Citrate synthase (gltA) gene primers (6) were also used. Two PCRs were conducted to maximize sensitivity. Specificity of N. helminthoeca–specific primers was shown by amplification studies of genomic DNA of A. phagocytophilum, Ehrlichia chaffeensis, E. canis, N. risticii, N. sennetsu, and N. helminthoeca. All amplicons were separated by electrophoresis in 1% agarose gels and purified before cloning (pGEM-T and pGEM-T Easy Vector Systems, Promega, Madison, WI, USA) and sequencing. The Maringa sequences obtained were compared with those in GenBank by using BLAST (http://www.ncbi.nlm.nih.gov/BLAST). Phylogenetic trees, sequence alignments, and identity tables were created by using Vector NTI Advance10 Software (Invitrogen, Carlsbad, CA, USA). GenBank accession numbers of Anaplasmataceae and their phylogenetic relationships are shown in the Figure. Figure Neighbor-joining phylogenetic trees of the 16S rRNA (rrs), RNA polymerase β-subunit (rpoB), and heat-shock protein (groESL) gene sequences of Anaplasmataceae families. Trees were constructed with Vector NTI Advance10 Software (Invitrogen, Carlsbad, ... Two dogs (N40–05, mesenteric lymph node, Maringa 1 and N20–04, Peyer's patch, Maringa 2) contained Neorickettsia spp. rrs, rpoB, or groESL genes. Both samples produced partial sequences for Neorickettsia spp. rrs gene; a similarity of 99% was observed for the 2 Maringa dog rrs sequences with N. sennetsu, N. risticii, and the Stellantchasmus falcatus (SF) agent. However, N. helminthoeca rpoB and groESL partial sequences were obtained only from dog 1. DNA identities of 100%, 82%, and 81% were observed between Maringa dog 1 sequences and N. helminthoeca, N. risticii, and N. sennetsu for the rpoB genes, respectively. All dogs were negative when tested with gltA gene primers. We observed 100% identity between the Maringa dog 1 sequence and N. helminthoeca groESL gene sequences. Similarities of 84%, 80%, and 79% were observed with N. sennetsu, the SF agent, and N. risticii, respectively. All positive controls showed bands of appropriate sizes, whereas negative controls yielded no products, confirming lack of amplicon contamination. This study demonstrates that 2 dogs from Maringa, Brazil, with pathologic lesions consistent with SPD (7) were infected with a Neorickettsia sp. The partial sequences from dog 1 were identical to N. helminthoeca rrs, groESL, and rpoB genes, confirming infection with this organism (2). To our knowledge, this is the first confirmed description of this organism beyond the known geographic area of SPD. The organism identified in Brazil has been named N. helminthoeca Maringa strain. Because of difficulty in recovering DNA from samples, need for a highly efficient PCR targeting small DNA regions, and limited sensitivity of the amplifications, sequences obtained for N. helminthoeca Maringa dog 1 (112 bp for rrs, 92 bp for groESL, 143 bp for rpoB) were short compared with those in GenBank (rrs 1,453 bp, groESL 1,914 bp, rpoB, 464 bp). Efficiency and sensitivity of targeting small DNA regions was necessary since storage and shipment of frozen samples were not optimal. Small DNA sequences are often suboptimal for delineation of phylogenetic relationships. Bootstrapping analyses showed poor resolution (<380/1,000 iterations) below the genus level for the short rrs region examined. However, both the short rpoB and groESL regions examined had high bootstrap values (941/1,000 and 995/1,000 iterations, respectively). This finding allowed differentiation of N. helminthoeca and the Brazilian dog strain from N. sennetsu, N. risticii, and other related Anaplasmataceae and provided a high degree of confidence in the identification. More work is being implemented to obtain longer sequences to confirm and extend these genotypic comparisons. We propose further study to isolate the pathogen from other dogs for comparative biologic analyses. Although SPD is caused by N. helminthoeca, infections by other Neorickettsia spp., including N. risticii (Potomac horse fever) and N. sennetsu (sennetsu fever), illustrate the potential of these widely distributed species to infect and cause disease in mammals and humans. Detection of N. helminthoeca in Brazilian dogs extends the range of this species and warrants a broad search for infections and spectrum of disease of Neorickettsia in animals and humans.
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Suspected cases of Neorickettsia-like organisms in Brazilian dogs.
Annals of the New York Academy of Sciences, 2004Co-Authors: Selwyn Arlington Headley, Odilon Vidotto, Diana G. Scorpio, J. Stephen Dumler, Joseph L. MankowskiAbstract:Preliminary findings of gross and histopathological lesions consistent with salmon poisoning disease in 10 dogs from southern Brazil are described. Lesions were restricted to the spleen, lymph nodes, and intestinal lymphoid tissues. Grossly, there was marked hyperplasia of mesenteric lymph nodes and Peyer's patches. Microscopic alterations were characterized by diffuse hyperplasia of intestinal lymphoid tissues and Peyer's patches. Intracytoplasmic organisms consistent with Neorickettsia helminthoeca were demonstrated by Giemsa stain in reticuloendothelial cells of the intestine, spleen, Peyer's patches, and lymph nodes. We have named this organism Neorickettsia helminthoeca-like because of its marked similarity with the agent described in the United States.
Philippe Brouqui - One of the best experts on this subject based on the ideXlab platform.
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Citrate synthase gene sequence: a new tool for phylogenetic analysis and identification of Ehrlichia.
Journal of clinical microbiology, 2001Co-Authors: Hisashi Inokuma, Philippe Brouqui, Michel DrancourtAbstract:The sequence of the citrate synthase gene (gltA) of 13 ehrlichial species (Ehrlichia chaffeensis, Ehrlichia canis, Ehrlichia muris, an Ehrlichia species recently detected from Ixodes ovatus, Cowdria ruminantium, Ehrlichia phagocytophila, Ehrlichia equi, the human granulocytic ehrlichiosis [HGE] agent, Anaplasma marginale, Anaplasma centrale, Ehrlichia sennetsu, Ehrlichia risticii, and Neorickettsia helminthoeca) have been determined by degenerate PCR and the Genome Walker method. The ehrlichial gltA genes are 1,197 bp (E. sennetsu and E. risticii) to 1,254 bp (A. marginale and A. centrale) long, and GC contents of the gene vary from 30.5% (Ehrlichia sp. detected from I. ovatus) to 51.0% (A. centrale). The percent identities of the gltA nucleotide sequences among ehrlichial species were 49.7% (E. risticii versus A. centrale) to 99.8% (HGE agent versus E. equi). The percent identities of deduced amino acid sequences were 44.4% (E. sennetsu versus E. muris) to 99.5% (HGE agent versus E. equi), whereas the homology range of 16S rRNA genes was 83.5% (E. risticii versus the Ehrlichia sp. detected from I. ovatus) to 99.9% (HGE agent, E. equi, and E. phagocytophila). The architecture of the phylogenetic trees constructed by gltA nucleotide sequences or amino acid sequences was similar to that derived from the 16S rRNA gene sequences but showed more-significant bootstrap values. Based upon the alignment analysis of the ehrlichial gltA sequences, two sets of primers were designed to amplify tick-borne Ehrlichia and Neorickettsia genogroup Ehrlichia (N. helminthoeca, E. sennetsu, and E. risticii), respectively. Tick-borne Ehrlichia species were specifically identified by restriction fragment length polymorphism (RFLP) patterns of AcsI and XhoI with the exception of E. muris and the very closely related ehrlichia derived from I. ovatus for which sequence analysis of the PCR product is needed. Similarly, Neorickettsia genogroup Ehrlichia species were specifically identified by RFLP patterns of RcaI digestion. If confirmed this technique will be useful in rapidly identifying Ehrlichia spp.
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Cytopathic effect, plaque formation, and lysis of Ehrlichia chaffeensis grown on continuous cell lines.
Infection and Immunity, 1994Co-Authors: Philippe Brouqui, Marie-laure BirgAbstract:Ehrlichiae are strict intracellular bacterial pathogens that parasitize leukocytes or other blood cells. Only six agents of the tribe Ehrlichieae, namely, Cowdria ruminantium, Neorickettsia helminthoeca, Ehrlichia risticii, Ehrlichia sennetsu, Ehrlichia canis, and Ehrlichia chaffeensis, have been adapted to growth in continuous cell lines. E. chaffeensis, the agent of human ehrlichiosis, has been cultured only in a cell line of canine origin. We adapted purified cell-free E. chaffeensis for growth in human embryonic lung (HEL) fibroblasts (HEL 299), green monkey kidney cells (Vero), and a human cervical epithelioid carcinoma (HeLa) cell line. We observed a cytopathic effect with both Vero cells and HEL cells and plaque formation with cellular lysis when infected Vero cells were cultured in agar. Human fibroblasts are already commonly used for the isolation of viruses, coexiellae, and rickettsiae. Furthermore, the capability of these cells to support the growth of ehrlichiae suggests that they may be useful for primary isolation of ehrlichiae as well. The cytopathic effect produced in Vero or HEL cells offers a very helpful indicator of the infection. Plaque formation in Vero cells is a new phenomenon not yet reported for ehrlichiae and will allow the titration of inocula and clonal purification of this bacterium.