Dog blood parasite infection in upland and lowland communities of northern Thailand: The role of environment and care of dog owners.

Dogs play an important role as hosts and reservoirs for many zoonotic diseases. Ehrlichiosis, babesiosis and hepatozoonosis are a group of canine vector-borne diseases that can be transmitted via ectoparasites from dog to dog and also from dog to humans. This study focused on three main blood parasites of dog (i.e., Babesia spp., Ehrlichia spp. and Hepatozoon spp.) among two different landscape types of eight villages of Santhong Sub-district, Nan Province, Thailand. In this study, 149 dogs were surveyed and blood samples were collected. Blood parasite infections in dogs were assessed using molecular detection approach. Babesia canis vogeli, Babesia gibsoni, Ehrlichia canis and Hepatozoon canis were detected with prevalence of infection at 10.7%, 8.1%, 3.4% and 0.7%, respectively. In terms of landscape type, prevalence of overall blood parasites, particularly Babesia spp. infections were higher in dogs living in upland forested areas (28.3%) compared to dogs from lowland agricultural areas (12.3%). Data obtained from the questionnaires on perceptions of dog owners showed that dogs raised all the time outside owner's house, and those dogs whose owners have never bathed and cleaned were more likely to be exposed to blood parasites. As infected dogs could play an important role as reservoirs of the blood parasites, attitude of dog owners may affect public health in terms of zoonotic disease transmission. Effective control measures and surveillance program of arthropod vectors and blood parasite infection in dogs still need to be advocated to minimize zoonotic disease transmission.

Anaplasma phagocytophilum in urban and peri-urban passerine birds in Ile-de-France.

Wild animals in general, birds in particular, play a key role in transporting ticks and propagating tick-borne pathogens. Several studies have confirmed the infection of birds with Anaplasma phagocytophilum, with overall prevalence varying widely from country to country and/or study to study. This zoonotic bacterium, transmitted mainly by ticks of the genus Ixodes, is responsible for granulocytic anaplasmosis in humans (HGA) and domestic animals (cats, dogs, horses). The disease is also called tick-borne fever (TBF) in ruminants. Extremely rare in the USA, TBF is very common in Europe, where it causes economic losses in livestock. Conversely, HGA is well established in the USA whereas only a few less severe cases have been observed in Europe. Current typing techniques support the existence of multiple variants with differences in virulence/pathogenicity and tropism for certain tick and host species. However, epidemiological cycles remain difficult to characterize in Europe. Several studies describe a cycle apparently involving only birds in Europe, but no such study has been conducted in mainland France. Our objectives were to search for A. phagocytophilum in passerine birds in the Ile-de-France region and to explore their diversity using groEL and ankA gene typing and multilocus sequence typing (MLST). Various tissues (spleen, liver, and skin) were collected from cadavers of 680 passerines between March and December 2021. The presence of A. phagocytophilum was detected by qPCR Taqman targeting the msp2 gene. Three blackbirds (Turdus merula) were found positive, representing detection rates of 0.4 % in all birds tested and 3.3 % in blackbirds. The higher frequency of detection in blackbirds could be at least partially explained by their lifestyle, as they feed on the ground. Analysis of the results of groEL and ankA typing and MLST from positive blackbirds support the hypothesis that the avian A. phagocytophilum strains in Ile-de-France are distinct from those found in mammals, and that they form their own cluster in Europe.

Detection of Anaplasma and Ehrlichia bacteria in humans, wildlife, and ticks in the Amazon rainforest.

Tick-borne bacteria of the genera Ehrlichia and Anaplasma cause several emerging human infectious diseases worldwide. In this study, we conduct an extensive survey for Ehrlichia and Anaplasma infections in the rainforests of the Amazon biome of French Guiana. Through molecular genetics and metagenomics reconstruction, we observe a high indigenous biodiversity of infections circulating among humans, wildlife, and ticks inhabiting these ecosystems. Molecular typing identifies these infections as highly endemic, with a majority of new strains and putative species specific to French Guiana. They are detected in unusual rainforest wild animals, suggesting they have distinctive sylvatic transmission cycles. They also present potential health hazards, as revealed by the detection of Candidatus Anaplasma sparouinense in human red blood cells and that of a new close relative of the human pathogen Ehrlichia ewingii, Candidatus Ehrlichia cajennense, in the tick species that most frequently bite humans in South America. The genome assembly of three new putative species obtained from human, sloth, and tick metagenomes further reveals the presence of major homologs of Ehrlichia and Anaplasma virulence factors. These observations converge to classify health hazards associated with Ehrlichia and Anaplasma infections in the Amazon biome as distinct from those in the Northern Hemisphere.

Molecular diagnosis and characterization of Anaplasma marginale and Ehrlichia ruminantium infecting beef cattle of Maputo Province, Mozambique.

BACKGROUND: Members of the Anaplasmataceae family, such as the Anaplasma and Ehrlichia species, cause economic losses and public health risks. However, the exact economic impact has not been comprehensively assessed in Mozambique due to limited data available on its basic epidemiology. Therefore, we investigated the molecular occurrence and identity of Anaplasma and Ehrlichia spp. infecting beef cattle in Maputo province, Mozambique. METHODS: A total of 200 whole blood samples were collected from apparently healthy beef cattle. Whole blood DNA was extracted and tested for presence of Anaplasma spp. and Ehrlichia ruminantium DNA through amplification of the 16S rRNA and map1 genes. Positive samples to Anaplasma spp. were subject to PCR assay targeting the A. marginale-msp5 gene. Amplicons obtained were purified, sequenced and subject to phylogenetic analyses. RESULTS: Anaplasma spp., A. marginale and E. ruminantium were detected in 153 (76.5%), 142 (71%) and 19 (9.5%) of all the samples analyzed, respectively. On this same sample group, 19 (9.5%) were co-infected with A. marginale and E. ruminantium. The 16S rRNA sequences of Anaplasma spp. obtained were phylogenetically related to A. marginale, A. centrale and A. platys. Phylogenetic analysis revealed that A. marginale-msp5 nucleotide sequences were grouped with sequences from Asia, Africa and Latin America, whereas E. ruminantium-map1 DNA nucleotide sequences were positioned in multiple clusters. CONCLUSION: Cattle in Maputo Province are reservoirs for multiple Anaplasma species. A high positivity rate of infection by A. marginale was observed, as well as high genetic diversity of E. ruminantium. Furthermore, five new genotypes of E. ruminantium-map1 were identified.

Assessment of the effect of long-term serum storage for retrospective serologic diagnosis of canine monocytic ehrlichiosis (Ehrlichia canis).

There is currently sparse information on the possible effect of long-term storage of serum specimens for the retrospective serodiagnosis of canine monocytic ehrlichiosis (CME). The aim of this study was to assess the agreement between the original serologic outcome and the results of a repeat indirect fluorescent antibody (IFA) assay for the detection of IgG antibodies against E. canis. A secondary aim was to compare the diagnostic performance of two commercially available point-of-care (POC) immunochromatographic (IC) assays. Archived serum samples originally tested as positive (n=66) or negative (n=19) for E. canis IgG antibodies and kept frozen at -20°C for a median of 22 years, were retrospectively examined by IFA and by two POC IC assays. Cohen's Kappa coefficient (0.748, p < 0.0001), indicated a substantial agreement between the original and repeat serologic testing results. An almost identical high sensitivity and moderate specificity were established for the two POC IC assays. Canine serum specimens on long-term storage may still be of value for seroepidemiologic surveys investigating the exposure to E. canis.

Anaplasma phagocytophilum infection associated with strong inflammatory response in 3 cats.

Anaplasmosis is a vector-borne disease caused by Anaplasma (A.) spp. which currently is still rarely diagnosed in cats. This article describes 3 independent cases of anaplasmosis in cats from different regions of Germany presented to veterinarians in 2021. All cats showed unspecific clinical signs, such as fever, reduced general condition, and decreased appetite. One cat additionally had generalized limb pain, another showed reluctance to move as well as vomiting. On complete blood cell count, only 1 of 3 cats showed mild thrombocytopenia. A. phagocytophilum was detected in blood samples of all 3 cats by polymerase chain reaction. Additionally, in 2 cats (in which blood smears were evaluated) morulae could be detected within neutrophilic granulocytes. Initially, all 3 cats had highly elevated serum amyloid A (SAA) concentrations. Treatment with doxycycline caused a rapid improvement of clinical signs, followed by a decrease of SAA concentrations to normal levels as well as negative PCR results after a treatment duration of at least 28 days. In cats with fever, otherwise unspecific clinical signs with only mild or no hematological changes, elevated SAA concentrations, and previous exposure to ticks, attending veterinarians should consider anaplasmosis as differential diagnosis.

A canine case of Ehrlichia canis infection without a history of being in an endemic area in Japan.

A mixed-breed, 8-year-old male dog developed neutropenia, thrombocytopenia, and hyperglobulinemia. Bone marrow hyperplasia and splenic plasmacytosis were cytologically observed. The dog had never been outside of Tokyo or Shizuoka Prefecture. Splenectomy was performed to confirm and remove the cause of splenic plasmacytosis. A histopathological diagnosis of splenic plasmacytoma was made; however, serum protein electrophoresis showed polyclonal gammopathy. Further screening was performed, and Ehrlichia canis infection was confirmed. The dog was treated with doxycycline for 5 weeks. After the antibiotic therapy, no relapse of neutropenia, thrombocytopenia, hyperglobulinemia, or positive polymerase chain reaction result of E. canis infection was observed for 3 years. Careful attention should be given to ehrlichiosis when exploring the cause of pancytopenia or hyperglobulinemia, regardless of the travel history.

Prevalence of subclinical infectious agents in a blood donor population tested on every donation.

OBJECTIVES: This study aimed to assess the prevalence of blood-borne infectious agents in healthy, client-owned dogs from a blood donor population in Portugal and Spain, and to address the importance of a screening protocol on every donation. MATERIALS AND METHODS: Client-owned healthy dogs were tested before each donation on a veterinary blood bank. Blood samples from new potential donors, and from regular donors, were tested by real-time polymerase chain reaction for Leishmania species, Ehrlichia species, Brucella species, Babesia species and Anaplasma species Serological tests were also performed for Leishmania species, Ehrlichia species and Dirofilaria immitis. All donors were tested for every infectious agent in each donation. RESULTS: The study found that out of a total of 8036 donors and 35,120 samples tested, 3.9% of blood donors tested positive for at least one of the agents, with the most prevalent being Anaplasma species (2.1%). Serological tests also revealed positive results in 14.0% of donors, with the highest percentage for Leishmania species (7.7%). Moreover, the study found that 28.2% of positive results were from dogs with negative results in donations performed 3 to 12 months before, and 18.0% of positive results were recent infections. CLINICAL SIGNIFICANCE: These findings indicate a high prevalence of infectious agents in seemingly healthy, selected dogs eligible to become blood donors in the Iberian Peninsula, highlighting the importance of regular testing on every donation. This study emphasises the importance of a regular screening protocol for every donation instead of annual testing, as is commonly performed in veterinary medicine.

Molecular Evidence of Ehrlichia canis (Rickettsiales: Anaplasmataceae) in Ticks (Ixodida: Ixodidae) Associated with Dogs (Carnivora: Canidae) from Nuevo Leon, Mexico.

Background: Ehrlichia canis is transmitted by ticks causing Canine monocytic ehrlichiosis, which is considered one of the most critical tickborne pathogens. Materials and Methods: This study aimed to identify by PCR technique E. canis in ticks associated with dogs from urban and rural homes in Nuevo Leon, Mexico. The study was conducted at 13 localities in eight municipalities from 2012 to 2021. Results: A total of 1873 ticks of three species were captured: Amblyomma tenellum, Dermacentor variabilis, and Rhipicephalus sanguineus s.l. The overall infection rate of E. canis in ticks was 59.12% (149/252). Of the 15 sequences, three haplotypes were identified. Conclusion: The urban transmission cycle of canine ehrlichiosis is demonstrated, where the potential vector is the tick R. sanguineus s.l.

Common and atypical presentations of Anaplasma phagocytophilum infection in equids with emphasis on neurologic and muscle disease.

BACKGROUND: Comprehensive descriptions of equids with granulocytic anaplasmosis (EGA) with neurologic or muscle disease and other atypical presentations are scarce in the literature. OBJECTIVE: Describe the clinical signs, laboratory findings, treatment, and outcome of equids with EGA with emphasis on neurologic and muscle disease. ANIMALS: Thirty-eight horses, 1 donkey. METHODS: Retrospective study. Equids with EGA were included. The electronic data base was searched from January 2000 to December 2022 using the words anaplasmosis, ehrlichiosis, granulocytic, and rickettsia. Signalment and clinical data were reviewed. Data were evaluated for normality using Shapiro-Wilk test. Parametric and nonparametric statistics were used for normally and non-normally distributed data. RESULTS: Common (41%) and other (59%) presentations were seen in horses ≥ 4 years of age (median, 14 years) with an overrepresentation of males (77%). Neurologic disease was common (41%), mainly presenting as diffuse symmetrical proprioceptive ataxia. Brain disease was less common manifesting as obtundation and cranial nerve deficits. Muscle disease was less common, with QH breeds with the variant causing myosin heavy chain myopathy (MYHM) having severe disease. Cavitary effusion, cardiomyopathy and disseminated intravascular coagulation (DIC) were uncommon. Clinical laboratory results varied depending on disease stage. Muscle enzyme activities were significantly higher in horses with muscle disease. Outcome was favorable with prompt tetracycline treatment. Death and long-term sequelae were not reported. CONCLUSIONS AND CLINICAL IMPORTANCE: Common and atypical presentations of EGA have a favorable outcome with prompt tetracycline treatment. Quarter horse breeds with muscle disease should be genotyped for MYHM.

Novel renal injury markers in dogs with ehrlichiosis.

Canine monocytic ehrlichiosis (CME) has been observed to impact renal function. Currently, the recognition of acute kidney injury is through the nonspecific biomarker serum creatinine (sCr). Novel markers of renal injury such as urinary clusterin (uClust) and urinary cystatin B (uCysB) may increase our understanding of the relationship between ehrlichiosis and renal cellular injury. The aim of this study was to evaluate novel renal injury biomarkers in dogs with acute CME. Twenty healthy dogs were enrolled in the control group (CG), and 16 dogs naturally infected with Ehrlichia canis were included in the Ehrlichia Group (EG). All dogs were followed for 45 days. EG dogs were treated with doxycycline twice daily for the first 30 days. Urine and serum were collected at: 0, 0.5, 1, 15, 30, and 45 days after start of treatment. Urine concentrations of uClust and uCysB were determined using a research ELISA immunoassay. A linear mixed model was used to estimate population mean of renal injury markers with patient as the random effect, and day and treatment as fixed effects. EG was observed to have higher uClust values compared to CG (estimated population mean EG: 213 ng/dL vs. CG: 84 ng/dL, P < 0.001). EG was observed to have higher uCysB values compared to CG (estimated population mean EG: 248 ng/dL vs. CG: 38 ng/dL, P < 0.001). Increases in uCysB and uClust suggest the presence of renal injury and a possible mechanism for the observed predisposition to chronic kidney disease in dogs with ehrlichiosis.

Mathematical model of Ehrlichia chaffeensis transmission dynamics in dogs.

Ehrlichia chaffeensis is a tick-borne disease transmitted by ticks to dogs. Few studies have mathematical modelled such tick-borne disease in dogs, and none have developed models that incorporate different ticks' developmental stages (discrete variable) as well as the duration of infection (continuous variable). In this study, we develop and analyze a model that considers these two structural variables using integrated semigroups theory. We address the well-posedness of the model and investigate the existence of steady states. The model exhibits a disease-free equilibrium and an endemic equilibrium. We calculate the reproduction number (T0). We establish a necessary and sufficient condition for the bifurcation of an endemic equilibrium. Specifically, we demonstrate that a bifurcation, either backward or forward, can occur at T0=1, leading to the existence, or not, of an endemic equilibrium even when T0<1. Finally, numerical simulations are employed to illustrate these theoretical findings.

Clinical and pathological factors associated with Ehrlichia canis in companion dogs.

INTRODUCTION: Canine monocytic ehrlichiosis (CME) is a disease caused by the Gram-negative bacteria Ehrlichia canis, a bacterium that affects domestic dogs but can also infect humans. The diagnosis implies a challenge due to its diversity in clinical manifestations. METHODOLOGY: The frequency of E. canis infection, risk factors, and clinical-pathological parameters associated with seropositivity were calculated with the PROC FREQ TABLES and PROC LOGISTIC procedures of the SAS statistical software. RESULTS: The study showed a seroprevalence of 26.62% (156/586). Association between seropositivity and risk factors was found. The age and the presence of ticks including clinical signs such as anorexia, seizures, cough, petechiae, epistaxis, and hematochezia, as well as multiple blood and biochemical alterations were analyzed. The logistic regression analysis showed a high predictive power (c = 0.98) for CME for thrombocytopenia, leukopenia, and anemia. CONCLUSIONS: The high prevalence of E. canis in endemic areas makes its diagnosis difficult. Thus, clinical signs must be considered, along with blood and biochemical alterations, as a possible predictor of the disease.

Phylogenetic analysis of Ehrlichia species isolated from horses and dogs in Iran.

This study aimed to determine the prevalence and phylogenetic analysis of Ehrlichia spp. in horses and dogs in Iran. Blood samples were collected from 400 animals, including 200 horses and 200 dogs, from five different provinces in Iran. Polymerase chain reaction (PCR) was used to detect Ehrlichia spp. based on amplification of the 16S rRNA gene. The semi-nested PCR method was used to amplify the dsb, TRP36, and gltA genes. The results showed that 4.5 % of the samples (3 % horses and 6 % dogs) were positive for Ehrlichia sp. The highest prevalence was observed in Kerman and Khuzestan, while the lowest was found in West Azerbaijan, Golestan, and Mazandaran. The study suggests that the populations of dogs and horses in the country should be considered important factors in the epidemiology of ehrlichiosis. Phylogenetic analysis based on the dsb and TRP36 genes revealed that the prevalent species were E. canis and E. ruminantium.

Molecular occurrence and genetic diversity of Ehrlichia canis in naturally infected dogs from Thailand.

Canine monocytic ehrlichiosis is cause by Ehrlichia canis resulting in hematologic disorders and severe clinical signs. The aim of this study was to scrutinize the molecular detection and genetic diversity of E. canis based on the trp36 gene in dogs from Thailand's northern and central regions. A total of 120 dogs blood samples were amplified for trp36 gene of E. canis using the polymerase chain reaction (PCR). Forty-seven out of 120 dog blood samples (39.16%, 47/120) were positive for E. canis the trp36 DNA with 790 bp of PCR amplicon size. The factor significantly associated with E. canis infection is animal housing status (p < 0.05). Sequence and phylogenetic analysis showed that E. canis trp36 gene of Thailand isolates was clustered into 1st clade with similarity ranging from 95.65 to 100% together with the US genogroup. The 14 haplotypes of the trp36 gene shown in TCS network exhibited that haplotype #1-4 was found in Thailand. The entropy analysis of the trp36 gene illustrated 751 polymorphic sites and 271 entropy peaks of nucleic and amino acid sequences, respectively. Hence, these findings are crucial for better understanding the epidemiology of Ehrlichia infection and could be helpful for implementing control measures in Thailand.

Evaluation of Anaplasma spp. seroprevalence in dogs and association with incidence of human anaplasmosis.

Point-of-care (POC) ELISA tests are routinely used in US veterinary practices to screen canine patients for antibodies to tick-transmitted pathogens. Results are also used to monitor spatial and temporal trends in canine seroprevalence, and these data can build awareness of the risk to humans of tick-transmitted diseases such as Lyme disease and anaplasmosis. This study utilized a second-generation test that has incorporated additional Anaplasma-specific peptides into a commercial POC ELISA test to allow detection of Anaplasma spp. antibodies earlier post-infection. A convenience population consisting of 19,894 canine samples from a US commercial diagnostic laboratory were tested using the second-generation POC ELISA test to describe regional Anaplasma spp. canine seroprevalence and assess correlation to anaplasmosis cases reported to Centers for Disease Control and Prevention by state. Antibodies to Anaplasma spp. were detected in 1646 samples (8.3%) with the Northeast and Midwest US census regions having the highest proportion of positive samples. At the state level, a significant correlation was found between canine Anaplasma spp. seroprevalence and human anaplasmosis incidence (r2 = 0.64). Although estimates of canine Anaplasma spp. seroprevalence presented here using the second-generation POC ELISA are generally increased, especially in the Northeast and Midwest, the regional distribution of canine samples testing positive for Anaplasma spp. antibodies is consistent with previous reports. The observed correlation with human anaplasmosis incidence indicates that results from the second-generation POC ELISA will continue to add value in epidemiological assessment of human anaplasmosis risk.

Canine ehrlichiosis seropositivity and associated factors in Kenya and Tanzania: a retrospective study.

Canine ehrlichiosis is an important tick-borne disease caused by bacteria in the Ehrlichia genus with species such as E. canis, E. ewingii and E. chaffeensis resulting in a severe dog illness. This study determined the occurrence of canine ehrlichiosis antibodies and its associated factors in Kenya and Tanzania. This was a retrospective study that evaluated laboratory records of 400 samples from Kenya and Tanzania submitted to Pathologists Lancet Kenya for the IDEXX SNAP 4Dx™ Plus test between the years 2016 and 2021. Records of all samples submitted to the Pathologists Lancet Kenya veterinary laboratory for the diagnostic tests were retrieved, examined, and compiled. Descriptive statistics and univariable and multivariable logistic regression were considered during analysis. The overall proportion of samples that tested positive for canine ehrlichiosis was 23% (92/400). Samples from Kenya accounted for 61% (245/400) of samples, and the percent positive was 31% (29/245). The samples from Tanzania accounted for 39% (155/400), and the percent positive was 69% (63/155). In the final model, the odds of a sample testing positive was 1.7 times for those submitted from July to December compared with those submitted from January to June. Blood samples of dogs from Tanzania had 5.31 times the odds of testing positive on the SNAP test when compared with those from Kenya. This study reports high percent positive in samples originating from Tanzania and those received during the year's second half.

Molecular Detection of Tick-Borne Pathogens in Dogs from Indigenous Communities, Amazon, Brazil.

Background: There are few reports of tick-borne pathogens infecting dogs living in indigenous communities of Brazil. Herein, we aimed to molecularly detect vector-borne pathogens in dogs from two indigenous communities in the Brazilian Amazon. Materials and Methods: We surveyed 327 dogs raised in Amazon region at 2 distinct indigenous ethnicities for the molecular detection of tick-borne pathogens (114 from Tapirapé and 213 from Karajá indigenous ethnicity). Whole blood samples were subjected to PCR and sequencing for Ehrlichia, Babesia, and Hepatozoon. Univariate and multivariate analyses were used to investigate the factors affecting the pathogen infection patterns in dogs. Results: Among the 327 blood samples, 40 were positive for Ehrlichia canis (12.2%), 2 for Anaplasma platys (0.61%), and 204 were positive for Hepatozoon canis (66.5%). Binary Logistic Regression showed association between E. canis infection and ethnicity (p = 0.010) and tick attachment (p = 0.041). Karajá dogs were 3.4 times (95% CI 1.3-8.5) more likely to be positive for E. canis than Tapirapé dogs. Dogs with ticks were 2.5 times more likely (95% CI 1.0-7.6) to be positive for E. canis than dogs without ticks. Conclusions: Our survey expands the knowledge regarding the presence of vector-borne pathogens in dogs from indigenous communities in the Amazon region.

Detection of Hemopathogens in Chelonoidis carbonaria: Microscopic, Molecular, Hematological, and Clinical Biochemistry Aspects.

Background: The growing contact between men and wild animals, caused by the increase in the population in urban centers and the destruction of the habitat of these animals, has been leading to a greater circulation of pathogens between humans and wildlife. Chelonoidis carbonaria, a tortoise found throughout South America, is one of the animals most rescued from animal trafficking and illegal breeding. Considering this situation, this study aimed to verify the occurrence of hemoparasites in C. carbonaria. Materials and Methods: Blood samples from 73 C. carbonaria were collected from animals located in (1) a rural commercial breeding unit, (2) an urban zoo, and (3) a center of rescued animal screening. Genomic DNA was extracted from these animals and used in PCRs to detect specific genomic fragments of haemogregarines (i.e., Hepatozoon and Hemolivia), and members of the Anaplasmataceae Family (i.e., Ehrlichia sp. and Anaplasma sp.). Blood samples were screened for hemopathogens by direct microscopy and were used for hematological assays, and serum samples were analyzed to determine the concentration of serum components. Results: It was found that 34.2% of the tortoises presented Sauroplasma sp. in their blood samples; these animals showed clinical biochemistry changes that indicate altered liver function. Two zoo animals were positive for Ehrlichia sp. in PCR, and also presented clinical biochemistry and hematological changes. Conclusion: The present project is pioneer in the detection of Ehrlichia sp. in C. carbonaria, and was able to identify changes in clinical biochemistry that can be a result of the infection by hemopathogens in this species.

Correlation between canine biochemical analytes and TRP36 ELISA seropositivity for Ehrlichia canis in Brazil.

BACKGROUND: Synthetic peptides of tandem repeat proteins (TRPs) have been employed in the serologic analysis of canine monocytic ehrlichiosis (CME) and used in epidemiological studies in Brazil. Based on molecular studies of TRPs, different genotypes of Ehrlichia canis have been described, but data on their pathogenicity remain unknown. OBJECTIVES: To correlate hepatic, renal, and muscular alterations in relation to different genotypes of E. canis in naturally exposed dogs using enzyme-linked immunosorbent assay (ELISA) with TRP19 and TRP36 synthetic protein antigens. METHODS: Two hundred serum samples were subjected to ELISA with the antigens of TRP19 and three genotypes (US, Br, and CR) of TRP36 of E. canis circulating in Brazil. Positive sera were evaluated through eight biochemical parameters, and the results were evaluated by principal component analysis and canonical correlation. RESULTS: ELISA revealed that 47 (23.5%) serum samples reacted to the BrTRP36 peptide, 36 (18%) reacted to the TRP19 peptide, and 8 (4%) reacted to the USTRP36 and CRTRP36 peptides separately. The most frequent biochemical alterations observed were for CK (59.4%), ALB (31.8%), GLO (28.9%), TP (28.9%), ALP (26%), urea (24.6%), creatinine (14.4%), and ALT (14.4%). The most prominent diagnostic method in canonical correlation analysis was BrTRP36, followed by TRP19, which correlated with hyperglobulinemia and hypoalbuminemia. CONCLUSIONS: Antibodies that reacted against the Brazilian genotype of E. canis correlated positively with hyperglobulinemia and increases in serum urea and creatinine. According to our results, the Brazilian genotype of E. canis is related to the chronic phase of CME.