Sequence and phylogenetic analysis of the 16S rRNA gene of Ehrlichia canis strains in dogs with clinical monocytic ehrlichiosis

Siarkou, Victoria I.; Mylonakis, Mathios E.; Bourtzi-Hatzopoulou, E.; Koutinas, A. F.

doi:10.1016/j.vetmic.2007.05.021

Cited by 42 publications

(33 citation statements)

References 28 publications

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“…Molecular characterization of evolutionarily conserved genes such as 16S rRNA has provided little information on strain diversity and suggests a high level of conservation (39,40,43,47,48). Similarly, the immunoreactive major outer membrane proteins p28 and p30 in U.S. and Venezuelan strains of E. canis appear to be highly conserved (13,29,30,46), an observation that was extended to characterized E. canis strains from six human patients from Venezuela (38).…”

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confidence: 99%

Genetic and Antigenic Diversities of Major Immunoreactive Proteins in Globally DistributedEhrlichia canisStrains

Zhang

Luo

Keysary

et al. 2008

Clin Vaccine Immunol

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The extent of knowledge regarding the diversity of globally distributed Ehrlichia canis strains has been limited to information gained from a few evolutionarily conserved genes. In this study, E. canis strains from the United States (strain Jake [US]), Brazil (strain São Paulo [BR]), and Israel (strain 611 [IS] and Ranana [IS-R]) were used to examine the antigenic and genetic diversities of four well-characterized major immunoreactive protein genes/proteins. gp36 and gp200 were the most divergent genes, and nucleotide substitutions in the gp36 tandem repeat region of the IS strain, but not the IS-R strain, resulted in two amino acid differences (S3P and P3T) in each nine-amino-acid repeat (epitope-containing region). DNA sequences of gp19 and gp140 were completely conserved in the US and BR strains, but differences were found in the Israeli strains, including two fewer tandem repeats in gp140 and a single amino acid substitution in gp19 from the IS strain. E. canis whole-cell lysates from each isolate were examined by Western immunoblotting using sera from naturally infected dogs from each country, and four major immunoreactive proteins (gp19, gp36, gp140, and gp200) were identified in each strain using protein-specific antisera. The US and BR strains exhibited highly conserved immunoreactive protein profiles, while some differences were identified in the IS strain. Sera from naturally infected Israeli dogs confirmed gene sequencing information, which demonstrated two distinct E. canis strains, defined by the gp36 gene. Conversely, gp19 was strongly reactive and present in all E. canis isolates. gp140 and gp200 were also present in all strains, although gp140 in the IS strain had two fewer tandem repeats and exhibited a smaller mass.

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confidence: 99%

Genetic and Antigenic Diversities of Major Immunoreactive Proteins in Globally DistributedEhrlichia canisStrains

Zhang

Luo

Keysary

et al. 2008

Clin Vaccine Immunol

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“…Mε βάση τα αποτελέσματα κυτταρολογικών, ορο-λογικών και μοριακών (PCr) εξετάσεων σε μια σειρά μελετών, έχει εξακριβωθεί η παρουσία των E. canis, A. phagocytophilum και A. platys (Κontos et al 1991, Mylοnakis et al 2004, Siarkou et al 2007). …”

Section: συχνες ερωτησεις πανω στην κλινικη χρησιμοτητα των ορολογικωunclassified

“…ωστόσο, στην Ελλάδα δεν υφίσταται τέτοιο πρόβλημα επειδή οι παραπάνω μικροοργα-νισμοί όπως και οι κρόττωνες που τους μεταδίδουν (Amblyomma americanum, A. hebraeum, Dermacentor variabilis) πιθανότατα δεν υπάρχουν (Papadopoulos et al 1996, Papazahariadou et al 2003, Siarkou et al 2007. Aσθενείς διασταυρούμενες ορολογικές αντι-δράσεις έχουν διαπιστωθεί μεταξύ της E. canis και των Neorickettsia helminthoeca and N. risticii που επίσης δεν έχουν αναφερθεί στην Ελλάδα (Harrus and Waner 2011).…”

Section: ποια είναι η ερμηνεία του αρνητικού ορολογικού αποτελέσματοςunclassified

Η κλινική χρησιμότητα των ορολογικών δοκιμών στη μονοκυτταρική ερλιχίωση (Ehrlichia canis) του σκύλου

Mylonakis

Koutinas

Θεοδώρου

et al. 2017

J Hellenic Vet Med Soc

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Canine monocytic ehrlichiosis (CME) is primarily caused by Ehrlichia canis, a member of the genus Ehrlichia (family: Anaplasmataceae). Serology is the most frequently used diagnostic modality in CME. Indirect fluorescent antibody (IFA) testing remains the “gold standard” for the detection and titration of the E. canis-specific antibodies; in addition, several user-friendly, in-clinic assays have recently gained tremendous popularity due to their practical and cost-effective nature. The latter assays provide mostly qualitative results and have a high diagnostic specificity; however, their sensitivity usually declines when the IFA-titers are lower than 1/320, suggesting a suboptimal performance in acutely infected dogs.Overall, a positive IgG antibody titer indicates past exposure to and infection by Ehrlichia canis or a closely related agent (e.g. E. chaffeensis, E. ewingii), while rarely, true false positives may adversely affect the interpretation. As a rule, a negative IgG antibody titer rules out exposure to E. canis, with the notable exception of the acute CME in which clinical and clinicopathological manifestations may preceed seroconversion which occurs 7-35 days post-infection. The latter problem may be overcome by testing paired serum samples obtained 2-3 weeks apart. Unlike IgG antibodies, IgM titers develop inconsistently in the course of the infection, thus, not justifying their routine measurement for diagnostic purposes. Importantly, IgG antibody titers do not reliably correlate with the duration of infection, the current carrier status, or the presence and severity of clinical disease. Because of the prolonged latent period and the persistent seropositivity following therapy or self-eradication of the infection, clinicians should be well aware that seroreactivity to E. canis, especially in an endemic area, does not unequivocally confirm that the clinical manifestations and the clinicopathological abnormalities are due to E. canis infection. The decision to treat a clinically healthy, seropositive dog may be particularly challenging, especially in endemic areas.A positive or negative polymerase chain reaction (PCR) result dictates towards or against treatment, respectively. If PCR is not available, the proper course of action should be decided on a case-by-case basis. The authors suggest treating these dogs if they are thrombocytopenic and/or hyperglobulinemic and no other potential causes of these abnormalities (e.g. pseudothrombocytopenia and/or comorbid conditions) can be demonstrated. The antibody kinetics is quite unpredictable, frequently persisting several months to years following eradication of the organism, which limits the value of serology as a post-treatment monitoring tool. This review article addresses a series of questions pertaining to the interpretation of E. canisspecific serology in the context of the clinical phase of the disease, the antibody kinetics, the sensitivity and specificity of the assays and the prior treatment status. The ultimate goal is to facilitate the clinical decision-making towards the diagnosis and post-treatment monitoring of the CME.

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“…The clinical symptoms commonly seen with this disease in infected dogs are fever, vomiting, arthralgia, rash, and diarrhea (5). Diagnosis is based on visualization of the morula in monocyte and enzymatic-immunoassay (4); however, as molecular tools 16SrRNA gene detection by PCR and sequencing have been successfully used for diagnosis (6,7). In Venezuela, E. canis was isolated from blood of an asymptomatic patient, and another study in infected dogs and ticks from the same region suggest that it is a zoonotic pathogen (2.8).…”

Section: Introductionmentioning

confidence: 99%

“…Las manifestaciones clínicas en los perros infectados son: fiebre, vómito, artralgia, rash, y diarrea (5). El diagnóstico se basa en la visualización de la mórula dentro del monocito e inmunoensayo-enzimático (4); sin embargo, las herramientas moleculares como la detección del gene 16SrRNA mediante PCR y secuenciación han sido utilizadas exitosamente para el diagnóstico (6,7). En Venezuela, se aisló E. canis en sangre de humano con presentación clínica asintomática; y posteriormente, otro estudio en perros y garrapatas infectadas de la misma región geográfica sugiriendo que es un patógeno de comportamiento zoonótico (2,8).…”

Section: Introductionunclassified

Primer análisis filogenético de Ehrlichia canis en perros y garrapatas de México. Estudio preliminar

Sosa-Gutiérrez¹,

Quintero-Martinez

Vargas-Sandoval

et al. 2016

Rev MVZ Córdoba

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Objective. Phylogenetic characterization of Ehrlichia canis in dogs naturally infected and ticks, diagnosed by PCR and sequencing of 16SrRNA gene; compare different isolates found in American countries. Materials and methods. Were collected Blood samples from 139 dogs with suggestive clinical manifestations of this disease and they were infested with ticks; part of 16SrRNA gene was sequenced and aligned, with 17 sequences reported in American countries. Two phylogenetic trees were constructed using the Maximum likelihood method, and Maximum parsimony. Results. They were positive to E. canis 25/139 (18.0%) dogs and 29/139 (20.9%) ticks. The clinical manifestations presented were fever, fatigue, depression and vomiting. Rhipicephalus sanguineus Dermacentor variabilis and Haemaphysalis leporis-palustris ticks were positive for E. canis. Phylogenetic analysis showed that the sequences of dogs and ticks in Mexico form a third group diverging of sequences from South America and USA. Conclusions. This is the first phylogenetic analysis of E. canis in Mexico. There are differences in the sequences of Mexico with those reported in South America and USA. This research lays the foundation for further study of genetic variability.

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Sequence and phylogenetic analysis of the 16S rRNA gene of Ehrlichia canis strains in dogs with clinical monocytic ehrlichiosis

Cited by 42 publications

References 28 publications

Genetic and Antigenic Diversities of Major Immunoreactive Proteins in Globally DistributedEhrlichia canisStrains

Genetic and Antigenic Diversities of Major Immunoreactive Proteins in Globally DistributedEhrlichia canisStrains

Η κλινική χρησιμότητα των ορολογικών δοκιμών στη μονοκυτταρική ερλιχίωση (Ehrlichia canis) του σκύλου

Primer análisis filogenético de Ehrlichia canis en perros y garrapatas de México. Estudio preliminar

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