Ehrlichia chaffeensis infection of sika deer, Japan

Hemopathogens in naturally infected bovine fetuses in Brazil

The transplacental transmission of parasites and hemoparasites is crucial for understanding the epidemiology of diseases. This study aimed to assess the prevalence of hemopathogens in bovine fetuses at various gestational periods. Samples were obtained from a slaughterhouse in the state of Minas Gerais, Brazil, and a total of 236 fetuses were collected. DNA extracted from blood samples (145) and organ samples (a pool of brain and spleen) (236) underwent a nested PCR (nPCR) assay to detect Babesia spp., Theileria spp., Trypanosoma vivax, Anaplasma marginale, Anaplasma bovis, Anaplasma phagocytophilum, Ehrlichia minasensis, and hemotropic Mycoplasma spp. Additionally, serological analysis of 145 plasma samples was conducted using the indirect fluorescent antibody test-IFAT to detect IgG against Babesia bovis, Babesia bigemina, A. marginale, and Trypanosoma vivax. The observed prevalence of transplacental transmission was 19.3 %, 6.2 %, 42.7 % and 2.7 %, for A. marginale, B. bigemina, 'Candidatus M. haemobos', and Mycoplasma wenyonii, respectively. The prevalence of A. marginale by gestational trimester was 16 % (13/81) in the second trimester and 23 % (14/60) in the third trimester, with no positive samples in the first trimester. Regarding the species B. bovis and B. bigemina, all evaluated animals tested negative by nPCR, and no serological evidence for B. bovis was found by the IFAT. Babesia bigemina demonstrated an overall seroprevalence of 6.2 % (9/145), with 4.8 % (7/145) in the last trimester and 1.3 % (2/145) in the second trimester of pregnancy. In total, 42.7 % (62/145) of blood samples were positive for 'Candidatus M. haemobos', with 42 % (34/81) in the middle trimester, and 43 % (26/60) in the final trimester of pregnancy. Mycoplasma wenyonni was detected in 2.7 % (4/145) blood samples, all in coinfection with 'C. M. haemobos'. The prevalence by pregnancy trimester was 25 % (1/4) in the first trimester; 1.2 % (1/81) in the second trimester and 3.3 % (2/60) in the third trimester of pregnancy. Hemopathogen DNA was detected in fetus blood samples but not the brain or spleen samples. All the samples were negative for T. vivax, Theileria spp., Anaplasma spp. and Ehrlichia spp. Overall, in this study, approximately 70 % of fetuses were positive for one or more of the studied parasites. No significant associations were observed between pairs of pathogens, except 'C. M. haemobos' and A. marginale.

Preparing Collared Peccary (Pecari tajacu Linnaeus, 1758) for Reintroduction into the Wild: A Screening for Parasites and Hemopathogens of a Captive Population

The reintroduction of captive animals to the wild helps restore endangered species, but it risks pathogen transmission, harming wild populations. Such transmission can impact the genetic diversity and long-term viability of these populations. This study assessed parasite diversity and load in captive Pecari tajacu, a species native to the Americas and culturally significant to Brazilian indigenous culture, prior to reintroduction. Samples from 24 peccaries were analyzed for ectoparasites, hemopathogens, and stool parasites with direct and molecular analysis. Findings showed that various parasites were present. Two peccaries (8.3%) were infested by the adult tick Amblyomma sculptum. Six (25.0%) tested positive for Trypanosoma evansi, four (16.7%) for hemobacteria of the family Anaplasmataceae, twelve (50.0%) for hemotropic Mycoplasma, and seven (29.2%) for Leishmania braziliensis. Stool samples indicated multiple parasites, with sixteen (66.7%) peccaries infected by Strongylida order parasites, Spiruridae in three (12.5%), and Ascaris suum in one (4.2%) animal. Cysts of Balantidium sp. were found in twenty (83.3%), Entamoeba polecki in five (20.8%), and Iodamoeba bütschlii in two (8.3%) peccaries. To our current knowledge, this is the first global report of Leishmania braziliensis, Iodamoeba bütschlii, and Entamoeba polecki in P. tajacu, irrespective of the environment, including both captivity and wild conditions. Some of these parasites are common in domestic animals, and others are zoonotic, indicating potential interspecies pathogen transmission.

Molecular survey of Anaplasma phagocytophilum and related variants in water buffaloes: The first detection of Anaplasma phagocytophilum-like 1

Anaplasma phagocytophilum infects various hosts and lead to mild to severe infection. Currently, two A.phagocytophilum-related variants have been documented in different countries. Although limited, there are studies revealing the presence of A.phagocytophilum in water buffaloes, but no study investigating A.phagocytophilum-like 1 and -like 2. A.phagocytophilum and related variants were investigated using PCR, PCR-RFLP, and DNA sequence analysis in water buffaloes in Türkiye. 364 buffalo blood samples were examined for A.phagocytophilum and related strains. Seven buffaloes were determined to be positive with PCR and PCR-RFLP revealed that all samples were A.phagocytophilum-like 1. According to the partial sequence of 16 S rRNA gene, A.phagocytophilum like-1 may split into two different variants. This work supplies the first molecular report of A.phagocytophilum-like 1 in water buffaloes. However, a lack of information is present on the pathogen's clinical manifestations and vector species. There is still a need to investigate vectors and clinical signs of the pathogen.

Candidatus Lariskella arthopodarum endosymbiont is the main factor differentiating the microbiome communities of female and male Borrelia-positive Ixodes persulcatus ticks

Ixodes persulcatus, a hard-bodied tick species primarily found in Asia and Eastern Europe, is a vector of pathogens to human and livestock hosts. Little research has been done on the microbiome of this species, especially using individual non-pooled samples and comparing different geographical locations. Here, we use 16S rRNA amplicon sequencing to determine the individual microbial composition of 85 Borrelia-positive I. persulcatus from the Japanese islands of Hokkaido and Honshu. The resulting data (164 unique OTUs) were further analyzed to compare the makeup and diversity of the microbiome by sex and location, as well as to determine the presence of human pathogens. We found that, while location had little influence, the diversity of I. persulcatus microbiome was predominantly dependent on sex. Males were seen to have higher microbiome diversity than females, likely due to the high presence of endosymbiotic Candidatus Lariskella arthropodarum within the female microbial communities. Furthermore, high read counts for five genera containing potentially human pathogenic species were detected among both male and female microbiomes: Ehrlichia, Borrelia, Rickettsia, Candidatus Neoehrlichia and Burkholderia and co-infections between different pathogens were frequent. We conclude that the microbiome of I. persulcatus depends mainly on sex and not geographical location and that the major difference between sexes is due to the high abundance of Ca. L. arthropodarum in females. We also stress the importance of this tick species as a vector of potential human pathogens frequently found in co-infections.

Molecular detection of vector-borne pathogens in semen from dogs in southeastern Brazil

Vector-borne pathogens (VBPs) are primarily transmitted by arthropod vectors, but secondary ways of transmission have been described, including via venereal route. Nonetheless, there is still limited research on possible sexual transmission of VBPs in dogs. We molecularly investigated the presence of vector-borne pathogens in semen from dogs living in an area where these agents are endemic. Upon PCR testing, seven out of 22 (31.8%) semen samples tested positive for at least one VBP, whereas simultaneous positivity to two or more pathogens was detected in three (13.6%) dogs. Among pathogens detected in semen, Trypanosoma cruzi (n = 1) and Leishmania infantum (n = 3) were identified to species level by restriction fragment length polymorphism analysis. Attempts to sequence PCR products from other pathogens were unsuccessful, but coupled epidemiological and molecular data suggest the presence of Anaplasma platys (n = 5), Babesia vogeli (n = 1) and Ehrlichia canis (n = 1) in semen from dogs. Further experimental studies would be needed to confirm the sexual transmission hypothesis for these VBPs and also the possible implications of these findings for canine reproduction.

Diversity unearthed by the estimated molecular phylogeny and ecologically quantitative characteristics of uncultured Ehrlichia bacteria in Haemaphysalis ticks, Japan

Ehrlichia species are obligatory intracellular bacteria transmitted by arthropods, and some of these species cause febrile diseases in humans and livestock. Genome sequencing has only been performed with cultured Ehrlichia species, and the taxonomic status of such ehrlichiae has been estimated by core genome-based phylogenetic analysis. However, many uncultured ehrlichiae exist in nature throughout the world, including Japan. This study aimed to conduct a molecular-based taxonomic and ecological characterization of uncultured Ehrlichia species or genotypes from ticks in Japan. We first surveyed 616 Haemaphysalis ticks by p28-PCR screening and analyzed five additional housekeeping genes (16S rRNA, groEL, gltA, ftsZ, and rpoB) from 11 p28-PCR-positive ticks. Phylogenetic analyses of the respective genes showed similar trees but with some differences. Furthermore, we found that V1 in the V1-V9 regions of Ehrlichia 16S rRNA exhibited the greatest variability. From an ecological viewpoint, the amounts of ehrlichiae in a single tick were found to equal approx. 6.3E+3 to 2.0E+6. Subsequently, core-partial-RGGFR-based phylogenetic analysis based on the concatenated sequences of the five housekeeping loci revealed six Ehrlichia genotypes, which included potentially new Ehrlichia species. Thus, our approach contributes to the taxonomic profiling and ecological quantitative analysis of uncultured or unidentified Ehrlichia species or genotypes worldwide.

Comparative Analysis of Genome of Ehrlichia sp. HF, a Model Bacterium to Study Fatal Human Ehrlichiosis

BACKGROUND

The genus Ehrlichia consists of tick-borne obligatory intracellular bacteria that can cause deadly diseases of medical and agricultural importance. Ehrlichia sp. HF, isolated from Ixodes ovatus ticks in Japan [also referred to as I. ovatus Ehrlichia (IOE) agent], causes acute fatal infection in laboratory mice that resembles acute fatal human monocytic ehrlichiosis caused by Ehrlichia chaffeensis. As there is no small laboratory animal model to study fatal human ehrlichiosis, Ehrlichia sp. HF provides a needed disease model. However, the inability to culture Ehrlichia sp. HF and the lack of genomic information have been a barrier to advance this animal model. In addition, Ehrlichia sp. HF has several designations in the literature as it lacks a taxonomically recognized name.

RESULTS

We stably cultured Ehrlichia sp. HF in canine histiocytic leukemia DH82 cells from the HF strain-infected mice, and determined its complete genome sequence. Ehrlichia sp. HF has a single double-stranded circular chromosome of 1,148,904 bp, which encodes 866 proteins with a similar metabolic potential as E. chaffeensis. Ehrlichia sp. HF encodes homologs of all virulence factors identified in E. chaffeensis, including 23 paralogs of P28/OMP-1 family outer membrane proteins, type IV secretion system apparatus and effector proteins, two-component systems, ankyrin-repeat proteins, and tandem repeat proteins. Ehrlichia sp. HF is a novel species in the genus Ehrlichia, as demonstrated through whole genome comparisons with six representative Ehrlichia species, subspecies, and strains, using average nucleotide identity, digital DNA-DNA hybridization, and core genome alignment sequence identity.

CONCLUSIONS

The genome of Ehrlichia sp. HF encodes all known virulence factors found in E. chaffeensis, substantiating it as a model Ehrlichia species to study fatal human ehrlichiosis. Comparisons between Ehrlichia sp. HF and E. chaffeensis will enable identification of in vivo virulence factors that are related to host specificity, disease severity, and host inflammatory responses. We propose to name Ehrlichia sp. HF as Ehrlichia japonica sp. nov. (type strain HF), to denote the geographic region where this bacterium was initially isolated.

Genetic profiling for Anaplasma and Ehrlichia species in ticks collected in the Eastern Cape Province of South Africa

Background

Anaplasma and Ehrlichia are emerging tick-borne pathogens that cause anaplasmosis and ehrlichiosis in humans and other animals worldwide. Infections caused by these pathogens are deadly if left untreated. There has been relatively no systematic survey of these pathogens among ticks in South Africa, thus necessitating this study. The presence of Anaplasma and Ehrlichia species were demonstrated by PCR in ticks collected from domestic ruminants at some selected communities in the Eastern Cape of South Africa. The ticks were identified by morphological characteristics and thereafter processed to extract bacterial DNA, which was analyzed for the presence of genetic materials of Anaplasma and Ehrlichia.

Results

Three genera of ticks comprising five species were identified. The screening yielded 16 positive genetic materials that were phylogenetically related to Ehrlichia sequences obtained from GenBank, while no positive result was obtained for Anaplasma. The obtained Ehrlichia sequences were closely related to E. chaffeensis, E. canis, E. muris and the incompletely described Ehrlichia sp. UFMG-EV and Ehrlichia sp. UFMT.

Conclusion

The findings showed that ticks in the studied areas were infected with Ehrlichia spp. and that the possibility of transmission to humans who might be tick infested is high.

Post-mortem hemoparasite detection in free-living Brazilian brown brocket deer (Mazama gouazoubira, Fischer 1814)

Tick-borne infections can result in serious health problems for wild ruminants, and some of these infectious agents can be considered zoonosis. The aim of the present study was the post-mortem detection of hemoparasites in free-living Mazama gouazoubira from Minas Gerais state, Brazil. The deer samples consisted of free-living M. gouazoubira (n = 9) individuals that died after capture. Necropsy examinations of the carcasses were performed to search for macroscopic alterations. Organ samples were collected for subsequent imprint slides, and nested PCR assays were performed to detect hemoparasite species. Imprint slide assays from four deer showed erythrocytes infected with Piroplasmida small trophozoites, and A. marginale corpuscles were observed in erythrocytes from two animals. A. marginale and trophozoite co-infections occurred in two deer. A nested PCR analysis of the organs showed that six of the nine samples were positive for Theileria sp., five were positive for A. phagocytophilum and three were positive for A. marginale, with co-infection occurring in four deer. The results of the present study demonstrate that post-mortem diagnostics using imprint slides and molecular assays are an effective method for detecting hemoparasites in organs.

Detection of Rickettsia and Ehrlichia spp. in Ticks Associated with Exotic Reptiles and Amphibians Imported into Japan

One of the major routes of transmission of rickettsial and ehrlichial diseases is via ticks that infest numerous host species, including humans. Besides mammals, reptiles and amphibians also carry ticks that may harbor Rickettsia and Ehrlichia strains that are pathogenic to humans. Furthermore, reptiles and amphibians are exempt from quarantine in Japan, thus facilitating the entry of parasites and pathogens to the country through import. Accordingly, in the current study, we examined the presence of Rickettsia and Ehrlichia spp. genes in ticks associated with reptiles and amphibians originating from outside Japan. Ninety-three ticks representing nine tick species (genera Amblyomma and Hyalomma) were isolated from at least 28 animals spanning 10 species and originating from 12 countries (Ghana, Jordan, Madagascar, Panama, Russia, Sri Lanka, Sudan, Suriname, Tanzania, Togo, Uzbekistan, and Zambia). None of the nine tick species are indigenous in Japan. The genes encoding the common rickettsial 17-kDa antigen, citrate synthase (gltA), and outer membrane protein A (ompA) were positively detected in 45.2% (42/93), 40.9% (38/93), and 23.7% (22/93) of the ticks, respectively, by polymerase chain reaction (PCR). The genes encoding ehrlichial heat shock protein (groEL) and major outer membrane protein (omp-1) were PCR-positive in 7.5% (7/93) and 2.2% (2/93) of the ticks, respectively. The p44 gene, which encodes the Anaplasma outer membrane protein, was not detected. Phylogenetic analysis showed that several of the rickettsial and ehrlichial sequences isolated in this study were highly similar to human pathogen genes, including agents not previously detected in Japan. These data demonstrate the global transportation of pathogenic Rickettsia and Ehrlichia through reptile- and amphibian-associated ticks. These imported animals have potential to transfer pathogens into human life. These results highlight the need to control the international transportation of known and potential pathogens carried by ticks in reptiles, amphibians, and other animals, in order to improve national and international public health.

The first clinical and laboratory evidence of co-infection by Anaplasma phagocytophilum and Ehrlichia canis in a Brazilian dog

Information on Anaplasma phagocytophilum in Brazil is very restricted. The aim of this study was to report clinical, parasitological, hematological and molecular evidence of a natural A. phagocytophilum infection of an urban Brazilian dog. The dog was an eight-month-old male French bulldog. Veterinary clinical examinations were performed three times: in April, June and December 2013. Biochemical and hematological analyses were performed during all examinations, and blood samples were collected for parasitological surveys in June and December. Morulae were present within neutrophils in blood smears from June. Both samples were PCR positive for A. phagocytophilum and Ehrlichia spp. Phylogenetic analysis revealed that the phylogenetic topology placed samples from this study in close proximity to other A. phagocytophilum isolates. Ehrlichia isolates from this dog were 100% identical to E. canis isolates, thus E. canis and A. phagocytophilum co-infection was diagnosed in this dog. Lethargy and skin lesions were the clinical signs observed in this dog. Abnormal hematological parameters, among those, severe thrombocytopenia, were observed in all three occasions. This finding highlights the growing importance of A. phagocytophilum in South America.

Human granulocytic Anaplasmosis, Japan

We retrospectively confirmed 2 cases of human Anaplasma phagocytophilum infection. Patient blood samples contained unique p44/msp2 for the pathogen, and antibodies bound to A. phagocytophilum antigens propagated in THP-1 rather than HL60 cells. Unless both cell lines are used for serodiagnosis of rickettsiosis-like infections, cases of human granulocytic anaplasmosis could go undetected.

Molecular detection of tick-borne pathogens of the family Anaplasmataceae in Brazilian brown brocket deer (Mazama gouazoubira, Fischer, 1814) and marsh deer (Blastocerus dichotomus, Illiger, 1815)

Deer are important natural reservoir hosts of Anaplasmataceae. The present study used nested PCR and nucleotide sequencing to evaluate the occurrence of Anaplasmataceae species in 23 free-living and six captive specimens of the cervids Mazama gouazoubira and Blastocerus dichotomus in Minas Gerais State, Brazil. Blood samples were tested for the presence of Ehrlichia and Anaplasma spp. using nPCR assays and sequencing of the msp4, msp1 and 16S rRNA genes. The identity of each sequence was confirmed by comparison with sequences available from GenBank using BLAST software. Of the animals investigated, 93.1% (27/29) were infected with haemoparasites including Anaplasma marginale (79.3%), Ehrlichia chaffeensis (3.4%), Anaplasma bovis (3.4%) and Anaplasma spp. (assigned to A. platys and A. phagocytophilum) (17.2%). Co-infection occurred in 20% (6/29) of the deer examined. Four (13.8%) were infected with A. marginale and Anaplasma sp., one (3.4%) was infected with A. marginale and E. chaffeensis, and one (3.4%) was infected with A. marginale and A. bovis. The results of the present study suggest that cross-protection does not occur in these deer. Immunological cross-reaction occurs when sera are tested diagnostically because these bacteria are closely related taxonomically, reinforcing the importance of molecular diagnosis followed by nucleotide sequencing.

Ehrlichiosis in Brazil

Ehrlichiosis is a disease caused by rickettsial organisms belonging to the genus Ehrlichia. In Brazil, molecular and serological studies have evaluated the occurrence of Ehrlichia species in dogs, cats, wild animals and humans. Ehrlichia canis is the main species found in dogs in Brazil, although E. ewingii infection has been recently suspected in five dogs. Ehrlichia chaffeensis DNA has been detected and characterized in mash deer, whereas E. muris and E. ruminantium have not yet been identified in Brazil. Canine monocytic ehrlichiosis caused by E. canis appears to be highly endemic in several regions of Brazil, however prevalence data are not available for several regions. Ehrlichia canis DNA also has been detected and molecularly characterized in three domestic cats, and antibodies against E. canis were detected in free-ranging Neotropical felids. There is serological evidence suggesting the occurrence of human ehrlichiosis in Brazil but its etiologic agent has not yet been established. Improved molecular diagnostic resources for laboratory testing will allow better identification and characterization of ehrlichial organisms associated with human ehrlichiosis in Brazil.

Molecular survey of Anaplasma and Ehrlichia infections of feral raccoons (Procyon lotor) in Hokkaido, Japan

Infection by Anaplasma and Ehrlichia in feral raccoons (Procyon lotor) in Hokkaido, Japan, was examined by molecular methods. A polymerase chain reaction (PCR) screen for Anaplasmataceae, based on 16S rRNA, showed that 38 (5.4%) of 699 raccoons examined were positive. These 38 positive samples were examined for Anaplasma phagocytophilum, Anaplasma bovis, Ehrlichia chaffeensis, and Ehrlichia canis infection by species-specific nested PCR. Nested PCR results indicated that 36 of the 38 samples were positive for A. bovis. All 38 samples were PCR negative for A. phagocytophilum, E. chaffeensis, and E. canis. This is the first report of the detection of A. bovis in the peripheral blood of raccoons. A total of 124 raccoons were infested with ticks, including Ixodes ovatus, Ixodes persulcatus, and Haemaphysalis spp. The rate of A. bovis infection in raccoons infested with Haemaphysalis spp. (46.7%, 7/15) was significantly higher than that in raccoons without Haemaphysalis spp. infestation (3.7%, 4/109, p < 0.001). No significant differences were observed in A. bovis infection rates between raccoons infested with I. ovatus or I. persulcatus and those not so infested. A total of four ticks (two males and two nymphs) and one larval pools from four raccoons showed positive for A. bovis-specific nested PCR. This results support the correlation between the A. bovis infection of raccoons and Haemaphysalis infestation. In conclusion, raccoons could be possible reservoir animals for A. bovis, and A. bovis infection in raccoons may be related to infestation with Haemaphysalis spp.