Development of a quadruplex PCR amplicon next generation sequencing assay for detection and differentiation of Bartonella spp

The genus Bartonella includes a group of species that are associated with a wide range of mammalian species, including human. It is challenging to detect all Bartonella species using a single molecular target due to its high genetic diversity. To solve this issue, we developed a quadruplex PCR amplicon sequencing assay using next-generation sequencing (NGS) technology for the detection and differentiation of Bartonella species. Our objective was to obtain the specific sequences of a minimum of two of the four target genes as confirmation of the identity of a particular Bartonella species using the assay. Four pairs of primers targeting specific regions on gltA, groEL, rpoB, and ssrA were evaluated for their capability of differentiating Bartonella species individually and collectively by performing singular PCR amplicon sequencing and quadruplex PCR amplicon sequencing. Using the quadruplex PCR amplicon sequencing, 24 Bartonella reference species were tested, all of which were successfully differentiated by at least two targets. Bartonella species were accurately identified from the artificially mixed DNA templates developed to simulate coinfections. The limit of detection was determined to be 1 fg based on testing a series of 10-fold dilutions of DNA from the Bartonella species. Testing of high DNA concentrations of 19 non-Bartonella species showed high specificity with none of the non-Bartonella species misclassified as Bartonella. Finally, the assay was evaluated by testing DNA extracts from field-collected body lice (Pediculus humanus humanus) and Norway rats (Rattus norvegicus): Bartonella quintana was detected and confirmed by three targets in the lice and Bartonella tribocorum was detected and confirmed by two targets in the rats. These results demonstrated that Bartonella species could be accurately and rapidly detected and differentiated into different tissue types using the quadruplex sequencing assay.

Prospective serological and molecular cross-sectional study focusing on Bartonella and other blood-borne organisms in cats from Catalonia (Spain)

Background

There is limited clinical or epidemiological knowledge regarding Bartonella infection in cats, and no serological studies have compared the presence of antibodies against different Bartonella species. Moreover, there are limited feline Bartonella studies investigating co-infections with other vector-borne pathogens and the associated risk factors. Therefore, the objective of this study was to investigate Bartonella spp. infections and co-infections with other pathogens in cats from Barcelona (Spain) based on serological and/or molecular techniques and to determine associated risk factors.

Methods

We studied colony and owned cats (n = 135). Sera were tested for Bartonella henselae-, Bartonella quintana-, and Bartonella koehlerae-specific antibodies using endpoint in-house immunofluorescence antibody assays. Bartonella real-time PCR (qPCR) and conventional PCR (cPCR) were performed. In addition, cPCR followed by DNA sequencing was performed for other pathogenic organisms (Anaplasma, Babesia, Cytauxzoon, Ehrlichia, Hepatozoon, hemotropic Mycoplasma, and Theileria spp.).

Results

From 135 cats studied, 80.7% were seroreactive against at least one Bartonella species. Bartonella quintana, B. koehlerae, and B. henselae seroreactivity was 67.4, 77.0, and 80.7%, respectively. Substantial to almost perfect serological agreement was found between the three Bartonella species. Colony cats were more likely to be Bartonella spp.-seroreactive than owned cats. Moreover, cats aged ≤ 2 years were more likely to be Bartonella spp.-seroreactive. Bartonella spp. DNA was detected in the blood of 11.9% (n = 16) of cats. Cats were infected with B. henselae (n = 12), B. clarridgeiae (n = 3), and B. koehlerae (n = 1). Mycoplasma spp. DNA was amplified from 14% (n = 19) of cat blood specimens. Cats were infected with Mycoplasma haemofelis (n = 8), Candidatus M. haemominutum (n = 6), Candidatus Mycoplasma turicensis (n = 4), and Mycoplasma wenyonii (n = 1). Anaplasma, Babesia, Cytauxzoon, Ehrlichia spp., Hepatozoon, and Theileria spp. DNA was not amplified from any blood sample. Of the 16 Bartonella spp.-infected cats based on PCR results, six (37%) were co-infected with Mycoplasma spp.

Conclusions

Bartonella spp. and hemoplasma infections are prevalent in cats from the Barcelona area, whereas infection with Anaplasma spp., Babesia, Cytauxzoon, Ehrlichia spp., Hepatozoon, and Theileria infections were not detected. Co-infection with hemotropic Mycoplasma appears to be common in Bartonella-infected cats. To our knowledge, this study is the first to document M. wenyonii is infection in cats.

Graphical Abstract

Ticks and Tick-Borne Pathogens Abound in the Cattle Population of the Rabat-Sale Kenitra Region, Morocco

Tick-borne pathogens cause the majority of diseases in the cattle population in Morocco. In this study, ticks were collected from cattle in the Rabat-Sale-Kenitra region of Morocco and identified morphologically, while tick-borne pathogens were detected in cattle blood samples via polymerase chain reaction assay and sequencing. A total of 3394 adult ixodid ticks were collected from cattle and identified as eight different tick species representing two genera, Hyalomma and Rhipicephalus. The collected ticks consisted of Hyalomma marginatum, Hyalomma anatolicum excavatum, Rhipicephalus sanguineus sensu lato, Rhipicephalus bursa, Hyalomma detritum, Hyalomma lusitanicum, Hyalomma dromedarii, and Hyalomma impeltatum. The overall prevalence of tick-borne pathogens in blood samples was 63.8%, with 29.3% positive for Babesia/Theileria spp., 51.2% for Anaplasma/Ehrlichia spp., and none of the samples positive for Rickettsia spp. Sequencing results revealed the presence of Theileria annulata, Babesia bovis, Anaplasma marginale, Theileria buffeli, Theileria orientalis, Babesia occultans, Anaplasma phagocytophilum, Anaplasma capra, Anaplasma platys, Anaplasma bovis, Ehrlichia minasensis, and one isolate of an unknown bovine Anaplasma sp. Crossbreeds, females, older age, and high tick infestation were the most important risk factors for the abundance of tick-borne pathogens, which occurred most frequently in Jorf El Melha, Sidi Yahya Zaer, Ait Ichou, and Arbaoua locations.

Molecular detection and characterization of Anaplasma platys and Ehrlichia canis in dogs from the Caribbean

Anaplasma platys is a tick-transmitted rickettsial pathogen, which is known to be the etiologic agent for cyclic thrombocytopenia in its primary canine host. Infections with this pathogen are also reported in cats, cattle and people. Similarly, Ehrlichia canis is another tick-borne rickettsial pathogen responsible for canine monocytic ehrlichiosis and is also reported to cause infections in people. We describe infections in dogs with these two pathogens on the Caribbean island of Grenada, West Indies by detection using molecular methods. We utilized a 16S rRNA gene-based PCR assay to detect both Ehrlichia and Anaplasma species by screening 155 canine blood samples from asymptomatic dogs. We found 18.7 % of the dogs to be positive for A. platys and 16.8 % for E. canis. Samples that tested positive for A. platys were further assessed by sequence analysis targeting 16S rRNA, 23S rRNA, citrate synthase (gltA) and heat shock protein (groEL) genes. Phylogenetic analysis revealed high correlation of A. platys 16S rRNA and gltA gene sequences with the geographic origins, while 23S rRNA and groEL gene sequences clustered independent of the geographic origins. This study represents an important step in defining the widespread distribution of active rickettsial infections in Caribbean dogs with no apparent clinical signs, thus posing a high risk for canine health and to a lesser extent to humans, as most dogs in the Caribbean are free-roaming.

Comparison of Anaplasma and Ehrlichia species-specific peptide ELISAs with whole organism-based immunofluorescent assays for serologic diagnosis of anaplasmosis and ehrlichiosis in dogs

OBJECTIVE

To compare the performance of 5 synthetic peptide-based ELISAs with that of 3 commercially available immunofluorescent assays (IFAs) for serologic diagnosis of anaplasmosis and ehrlichiosis in dogs.

SAMPLE

A convenience set of 109 serum samples obtained before and at various times after inoculation for 23 dogs that were experimentally infected with Anaplasma phagocytophilum, Anaplasma platys, Ehrlichia canis, Ehrlichia chaffeensis, or Ehrlichia ewingii and 1 uninfected control dog in previous studies.

PROCEDURES

All serum samples were assessed with 5 synthetic peptide-based ELISAs designed to detect antibodies against A phagocytophilum, A platys, E canis, E chaffeensis, and E ewingii and 3 whole organism-based IFAs designed to detect antibodies against A phagocytophilum, E canis, and E chaffeensis. The species-specific seroreactivity, cross-reactivity with the other tick-borne pathogens (TBPs), and diagnostic sensitivity and specificity were calculated for each assay and compared among assays.

RESULTS

All serum samples obtained from dogs experimentally infected with a TBP yielded positive results on a serologic assay specific for that pathogen. In general, sensitivity was comparable between ELISAs and IFAs and tended to increase with duration after inoculation. Compared with the IFAs, the corresponding ELISAs were highly specific and rarely cross-reacted with antibodies against other TBPs.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that peptide-based ELISAs had enhanced specificity relative to whole organism-based IFAs for detection of antibodies against Anaplasma and Ehrlichia spp, which should facilitate accurate diagnosis and may help detect dogs coinfected with multiple TBPs.

Role of vector-borne pathogens in the development of fever in cats: 1. Flea-associated diseases

PRACTICAL RELEVANCE

There has been increasing identification of vector-borne pathogens in cats presented to veterinary clinics around the world for evaluation of fever and the associated secondary effects, such as signs of depression and loss of appetite.

AIM

The aim of this article is to summarize the clinically relevant information concerning fever in cats that is associated with pathogens known or suspected to be vectored by fleas, with an emphasis on presenting clinical abnormalities and optimal diagnostic, treatment and prevention strategies. Fever in cats that is associated with pathogens vectored by ticks or sandflies is discussed in Part 2 of this article series.

Role of vector-borne pathogens in the development of fever in cats: 2. Tick- and sandfly-associated diseases

PRACTICAL RELEVANCE

There has been increasing identification of vector-borne pathogens in cats presented to veterinary clinics around the world for evaluation of fever and the associated secondary effects, such as signs of depression and loss of appetite.

AIM

The aim of this article is to summarize the clinically relevant information concerning fever in cats that is associated with pathogens vectored by ticks or sandflies, with an emphasis on presenting clinical abnormalities and optimal diagnostic, treatment and prevention strategies. Fever in cats associated with pathogens known or suspected to be vectored by fleas was discussed within Part 1 of this two-part article series.

Molecular and serological survey of carnivore pathogens in free-roaming domestic cats of rural communities in southern Chile

Owned, free-roaming domestic cats are abundant in the Chilean countryside, having high probability of contact with wildlife and potentially participating as reservoirs of zoonotic pathogens. In the present study, 131 cats from two remote study areas (Valdivia and Chiloe Island) in southern Chile were analyzed for infection/exposure to eight pathogens. Serum samples from 112 cats were tested for antigens against feline leukemia virus (FeLV antigen-ELISA) and antibodies against feline immunodeficiency virus (FIV-ELISA) and canine distemper virus (CDV-serum neutralization), yielded occurrence of 8.9, 1.7 and 0.8% respectively. The presence of DNA of five vector-borne pathogens, piroplasmids, Ehrlichia spp., Anaplasma spp., Rickettsia spp. and Bartonella spp. was investigated in thirty cats. Overall observed occurrence was 6.6% (2/30) for both Anaplasma platys, and B. henselae, and 3.3% (1/30) for both Bartonella sp. and Theileria equi. Observed occurrence for all vector-borne pathogens in Valdivia area was significantly higher than in Chiloe Island (5/15 vs 0/15; P=0.04). Our results represent the first description of exposure to CDV and DNA detection of T. equi and A. platys in domestic cats in Chile. The results highlight the importance of performing pathogen screening in owned, free-roaming rural cats to evaluate their potential role as reservoirs of infection and vectors for disease transmission to wildlife.

Feline Vector-Borne Diseases in North America

"In North America, with the exceptions of Bartonella henselae and Cytauxzoon felis, feline vector-borne diseases (FVBDs) have been minimally studied in domestic cats. Cats can be infected with many of the same vector-borne pathogens that infect dogs. Nonspecific clinical signs linked to FVBDs and low prevalence of certain vector-borne pathogens contribute to a limited awareness of FVBDs in sick cats. As clinicians become informed about FVBDs and as vector-borne disease diagnostics are routinely applied to evaluate sick cats, we will gain a stronger understanding of vector-borne pathogens in cats. This article focuses on recent findings related to FVBDs."

Molecular detection, characterization of Anaplasma spp. in domestic cats from Rio de Janeiro state

Species of the genus Anaplasma, in the family Anaplasmatacae, are responsible to vector-borne diseases that affecting animals and humans. Feline anaplasmosis is poorly reported in Brazil. This study aimed at investigating the occurrence of Anaplasma spp. in domestic cats from Greater Rio de Janeiro, and evaluating hematological changes associated with this rickettsial infection. Were sampled 216 cats, we performed nested PCR (nPCR) and real-time PCR (qPCR) assays targeting A. platys-16S-rDNA, A. platys-gltA and A. phagocytophilum-msp2 sequences. As evaluated with gltA-qPCR the frequency of cats positive for A. platys was 3.7% (n = 8/216) and by 16S-rDNA nested-PCR it was 0.9% (n = 2/216). No cats were positive to msp2-qPCR to A. phagocytophilum. The sequences of A. platys presented 100% similarity with previously described isolates around the world and Brazil. Two cats that were positive in the gltA-qPCR reactions have platelet inclusions in the microscopic examination. However, no significant (p > 0.05) hematological changes were observed, probably due to low parasite load. This study showed that A. platys occur in domestic cats from Greater Rio de Janeiro. Further studies are needed to more precisely characterize these organisms.

Bartonellosis, One Health and all creatures great and small

BACKGROUND

Bartonellosis is a zoonotic infectious disease of worldwide distribution, caused by an expanding number of recently discovered Bartonella spp.

OBJECTIVES

This review serves as an update on comparative medical aspects of this disease, including the epidemiology, pathogenesis, clinical diagnosis, treatment and challenges.

RESULTS

Of comparative medical importance, Bartonella spp. are transmitted by several arthropod vectors, including fleas, keds, lice, sand flies, ticks and, potentially, mites and spiders. Prior to 1990, there was only one named Bartonella species (B. bacilliformis), whereas there are now over 36, of which 17 have been associated with an expanding spectrum of animal and human diseases. Recent advances in diagnostic techniques have facilitated documentation of chronic bloodstream and dermatological infections with Bartonella spp. in healthy and sick animals, in human blood donors, and in immunocompetent and immunocompromised human patients. The field of Bartonella research remains in its infancy and is rich in questions, for which patient relevant answers are badly needed. Directed Bartonella research could substantially reduce a spectrum of chronic and debilitating animal and human diseases, and thereby reduce suffering throughout the world.

CONCLUSION

A One Health approach to this emerging infectious disease is clearly needed to define disease manifestations, to establish the comparative infectious disease pathogenesis of this stealth pathogen, to validate effective treatment regimens and to prevent zoonotic disease transmission.

Anaplasma, Ehrlichia and Rickettsia species infections in cats: European guidelines from the ABCD on prevention and management

OVERVIEW

Anaplasma species, Ehrlichia species and Rickettsia species are vector-borne pathogens infecting a wide variety of mammals, but causing disease in very few of them. Infection in cats: Anaplasma phagocytophilum is the most important feline pathogen among these rickettsial organisms, and coinfections are possible. Little information is available on the pathogenesis of these agents in cats. Clinical signs are usually reported soon after tick infestation. They are mostly non-specific, consisting of fever, anorexia and lethargy. Joint pain may occur. Infection in humans: Some rickettsial species ( A phagocytophilum, Ehrlichia chaffeensis, Ehrlichia ewingii, Rickettsia conorii, Rickettsia rickettsii, Rickettsia felis, Rickettsia typhi and Candidatus Neoehrlichia mikurensis) are of zoonotic concern. Direct contact with cat saliva should be avoided because of potential contamination by R felis. Infected cats are 'sentinels' of the presence of rickettsial pathogens in ticks and fleas in a given geographical area, and they signal a risk for people exposed to vectors.

Prevalence study and risk factor analysis of selected bacterial, protozoal and viral, including vector-borne, pathogens in cats from Cyprus

Background

Feline infectious agent studies are lacking in Cyprus. The aims of this study were to determine the prevalence and risk factors for various feline infectious agents, including feline vector-borne pathogens (FVBP), in cats from Cyprus.

Methods

A cross-sectional, descriptive, multicentre study was performed on 174 feline samples [138 owned and 36 shelter-feral, including both healthy (43) and non-healthy (131), cats] from private veterinary clinics from all six districts of Cyprus. Real-time quantitative polymerase chain reaction (qPCR) assays were used to detect Mycoplasma haemofelis (Mhf), “Candidatus Mycoplasma haemominutum” (CMhm) and “Candidatus Mycoplasma turicensis” (CMt). The population was tested for four FVBP including Bartonella henselae and Leishmania spp. using qPCR, while conventional PCR assays were used to detect Ehrlichia/Anaplasma spp. and Hepatozoon spp. Serological assays were performed to detect Leishmania infantum antibodies, feline leukaemia virus (FeLV) antigen and feline immunodeficiency virus (FIV) antibodies. Statistical analysis was performed to test associations and possible risk factors between variables and infectious agents.

Results

Ninety-six (55.2%) of the 174 cats were PCR-positive for at least one infectious agent. Forty-six cats (26.4%) were haemoplasma positive, including 13 (7.5%) for Mhf, 36 (20.7%) for CMhm and 12 (6.9%) for CMt. Sixty-six cats (37.9%) were positive for Hepatozoon spp., while 19 (10.9%) were positive for B. henselae, four (2.3%) for Leishmania spp. and one (0.6%) for Ehrlichia/Anaplasma spp. Sequencing revealed the presence of Hepatozoon felis, L. infantum and Anaplasma platys. Of the 164 cats that underwent retroviral serology, 10 (6.1%) were FeLV-positive and 31 (18.9%) were FIV-positive, while L. infantum serology was positive in 7 (4.4%) of the 160 cats tested. Multivariable logistic regression revealed significant associations for various infectious agents including L. infantum with each of Hepatozoon spp. and CMt infection.

Conclusions

A high prevalence of infectious agents was found in cats from Cyprus with Mhf, CMhm, CMt, L. infantum, B. henselae, H. felis, A. platys, FeLV and FIV infections reported for the first time. The significant associations between different pathogens provide a better understanding of similarities in the epidemiology of these pathogens and interactions between them.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-017-2063-2) contains supplementary material, which is available to authorized users.

Genetic diversity and molecular epidemiology of Anaplasma

Anaplasma are obligate intracellular bacteria of cells of haematopoietic origin and are aetiological agents of tick-borne diseases of both veterinary and medical interest common in both tropical and temperate regions. The recent disclosure of their zoonotic potential has greatly increased interest in the study of these bacteria, leading to the recent reorganisation of Rickettsia taxonomy and to the possible discovery of new species belonging to the genus Anaplasma. This review is particularly focused on the common and unique characteristics of Anaplasma marginale and Anaplasma phagocytophilum, with an emphasis on genetic diversity and evolution, and the main distinguishing features of the diseases caused by the different Anaplasma spp. are described as well.

PCR screening of tick-borne agents in sensitive conservation areas, Southeast Portugal

The Southeast region of Portugal, particularly the Guadiana valley, is currently the reintroduction territory of Lynx pardinus (Iberian lynx), one of the most endangered felids in the world that is only found in the Iberian Peninsula. Over the last century, populations have declined, placing L. pardinus at extremely high risk of extinction in the wild and relying on reintroduction projects. Among the aspects taken into account in the establishment of new populations is the sanitary status of the selected habitats, especially concerning infectious diseases, including tick-borne pathogens (TBPs). This study presents the results of TBPs survey on ticks collected at sensitive conservation areas of Southeast Portugal. From 2012 to 2014, 231 ticks obtained from vegetation, sympatric domestic and wild animals were submitted for analysis. The presence of Babesia spp., Cytauxzoon spp., Theileria spp., Hepatozoon spp., Anaplasma spp., Ehrlichia spp., Candidatus Neoehrlichia mikurensis, among other Anaplasmataceae, and Coxiella burnetii were investigated by PCR. Six tick species were recorded, Dermacentor marginatus (n = 13/5.6%), Hyalomma lusitanicum (n = 175/75.8%), Ixodes ricinus (n = 4/1.7%), Rhipicephalus bursa (n = 7/3.0%), R. pusillus (n = 21/9.1%) and R. sanguineus sensu lato (n = 11/4.8%). The molecular screening confirmed the presence of two tick-borne pathogens, C. burnetii (N = 34) and Anaplasma platys (N = 1), and one tick-endosymbiont, Candidatus Midichloria mitochondrii (N = 45). The results obtained provide new information on the circulation of ticks and TBPs with potential veterinary importance in Iberian lynx habitat.

Alpha proteobacteria of genusAnaplasma(Rickettsiales: Anaplasmataceae): Epidemiology and characteristics ofAnaplasmaspecies related to veterinary and public health importance

TheAnaplasmaspecies are important globally distributed tick-transmitted bacteria of veterinary and public health importance. These pathogens, cause anaplasmosis in domestic and wild animal species including humans.Rhipicephalus, Ixodes, DermacentorandAmblyommagenera of ticks are the important vectors ofAnaplasma.Acute anaplasmosis is usually diagnosed upon blood smear examination followed by antibodies and nucleic acid detection. All age groups are susceptible but prevalence increases with age. Serological cross-reactivity is one of the important issues amongAnaplasmaspecies. They co-exist and concurrent infections occur in animals and ticks in same geographic area. These are closely related bacteria and share various common attributes which should be considered while developing vaccines and diagnostic assays. Movement of susceptible animals from non-endemic to endemic regions is the major risk factor of bovine/ovine anaplasmosis and tick-borne fever. Tetracyclines are currently available drugs for clearance of infection and treatment in humans and animals. Worldwide vaccine is not yet available. Identification, elimination of reservoirs, vector control (chemical and biological), endemic stability, habitat modification, rearing of tick resistant breeds, chemotherapy and tick vaccination are major control measures of animal anaplasmosis. Identification of reservoirs and minimizing the high-risk tick exposure activities are important control strategies for human granulocytic anaplasmosis.

Prevalence of selected rickettsial infections in cats in Southern Germany

Prevalence of Anaplasma, Ehrlichia, Neorickettsia, and Wolbachia DNA in blood of 479 cats collected in different veterinary clinics in Southern Germany was determined using a previously published conventional PCR using 16S-23S intergenic spacer primers (5' CTG GGG ACT ACG GTC GCA AGA C 3' - forward; 5' CTC CAG TTT ATC ACT GGA AGT T 3' - reverse). Purified amplicons were sequenced to confirm genus and species. Associations between rickettsial infections, and feline immunodeficiency virus (FIV), as well as feline leukemia virus (FeLV) status were evaluated. Rickettsial prevalence was 0.4% (2/479; CI: 0.01-1.62%). In the two infected cats, Anaplasma phagocytophilum DNA was amplified. These cats came from different environment and had outdoor access. Both were ill with many of their problems likely related to other diseases. However, one cat had neutrophilia with left shift and the other thrombocytopenia potentially caused by their A. phagocytophilum infection. There was no significant difference in the FIV and FeLV status between A. phagocytophilum-negative and -positive cats. A. phagocytophilum can cause infection in cats in Southern Germany, and appropriate tick control is recommended.

Evidence of Anaplasma phagocytophilum and Borrelia burgdorferi infection in cats after exposure to wild-caught adult Ixodes scapularis

Cats are infected by Anaplasma phagocytophilum and Borrelia burgdorferi when exposed to infected Ixodes scapularis (black-legged ticks). The purpose of our study was to allow wild-caught I. scapularis to feed on healthy research cats (n = 4) and temporally evaluate for A. phagocytophilum DNA in blood by a polymerase chain reaction (PCR) assay as well as for antibody responses to the B. burgdorferi C6 peptide, to the A. phagocytophilum P44 peptide, and to a novel A. phagocytophilum peptide (P44-4). Prior to I. scapularis infestation, all cats were negative for antibodies against both organisms based on a kit optimized for dog serum, and negative for A. phagocytophilum DNA in blood using a conventional PCR assay. Using the pre-infestation samples, an enzyme-linked immunosorbent assay for detecting antibodies against the P44-4 peptide was optimized. Cats were infested with wild-caught I. scapularis for 7 days. Genomic DNA of A. phagocytophilum was amplified from the blood before antibodies were detected in all 4 cats. Antibodies against the C6 peptide, P44 peptide, and P44-4 peptide were detected in the sera of all 4 cats. Antibodies against P44-4 were detected prior to those against P44 in 3 out of 4 cats. The results suggest that a PCR assay should be considered in acutely ill cats with suspected anaplasmosis that are seronegative.

Serological and molecular analysis of feline vector-borne anaplasmosis and ehrlichiosis using species-specific peptides and PCR

Background

With the exception of Bartonella spp. or Cytauxzoon felis, feline vector-borne pathogens (FVBP) have been less frequently studied in North America and are generally under-appreciated as a clinical entity in cats, as compared to dogs or people. This study investigated selected FVBP seroreactivity and PCR prevalence in cats using archived samples.

Methods

Feline blood samples submitted to the Vector Borne Diseases Diagnostic Laboratory (VBDDL) at North Carolina State University College of Veterinary Medicine (NCSU-CVM) between 2008 and 2013 were tested using serological assays and PCR. An experimental SNAP® Multi-Analyte Assay (SNAP® M-A) (IDEXX Laboratories, Inc. Westbrook, Maine, USA) was used to screen all sera for antibodies to Anaplasma and Ehrlichia genus peptides and A.phagocytophilum, A.platys, B.burgdorferi, E.canis, E.chaffeensis, and E.ewingii species-specific peptides. PCR assays were used to amplify Anaplasma or Ehrlichia DNA from extracted ethylenediaminetetraacetic acid (EDTA)-anti-coagulated blood samples. Amplicons were sequenced to identify species.

Results

Overall, 7.8 % (56/715) of cats were FVBP seroreactive and 3.2 % (13/406) contained Anaplasma or Ehrlichia DNA. Serologically, B.burgdorferi (5.5 %) was the most prevalent FVBP followed by A.phagocytophilum (1.8 %). Ehrlichia spp. antibodies were found in 0.14 % (12/715) of cats with species-specific seroreactivity to E.canis (n = 5), E.ewingii (n = 2) and E.chaffeensis (n = 1). Of seropositive cats, 16 % (9/56) were exposed to more than one FVBP, all of which were exposed to B.burgdorferi and either A.phagocytophilum (n = 7) or E.ewingii (n = 2). Based upon PCR and DNA sequencing, 4, 3, 3, 2, and 1 cat were infected with A.phagocytophilum, A.platys, E. ewingii, E. chaffeensis and E.canis, respectively.

Conclusions

Cats are exposed to and can be infected with vector-borne pathogens that commonly infect dogs and humans. To our knowledge, this study provides the first evidence for E.chaffeensis and E.ewingii infection in naturally-exposed cats in North America. Results from this study support the need for regional, serological and molecular FVBP prevalence studies, the need to further optimize serodiagnostic and PCR testing for cats, and the need for prospective studies to better characterize clinicopathological disease manifestations in cats infected with FVBP.

Guideline for veterinary practitioners on canine ehrlichiosis and anaplasmosis in Europe

Canine ehrlichiosis and anaplasmosis are important tick-borne diseases with a worldwide distribution. Information has been continuously collected on these infections in Europe, and publications have increased in recent years. Prevalence rates are high for Ehrlichia and Anaplasma spp. infections in dogs from different European countries. The goal of this article was to provide a practical guideline for veterinary practitioners on the diagnosis, treatment, and prevention of ehrlichiosis and anaplasmosis in dogs from Europe. This guideline is intended to answer the most common questions on these diseases from a practical point of view.

Anaplasma platys in bone marrow megakaryocytes of young dogs

Anaplasma platys is an obligate intracellular rickettsial pathogen that infects platelets of dogs, forming basophilic intracellular morulae. In the present report, cellular inclusions were documented in bone marrow thrombocyte precursors of two young naturally infected dogs, indicating that A. platys can infect megakaryocytes and promegakaryocytes.