Improved sensitivity of PCR for diagnosis of human granulocytic ehrlichiosis using epank1 genes of Ehrlichia phagocytophila-group ehrlichiae

First molecular evidence of Anaplasma platys infection in a dog (Labrador retriever) from Bulgaria

Background

In recent years, the One Health approach and vector-borne diseases have become an increasingly topical problem around the world. In addition, climate change has a significant impact on zoonoses and public health. We present a case report of tick-borne disease in a dog.

Case Description

A clinical case of Anaplasma platys infection in a 10-year-old female dog (Labrador retriever) is described. Clinical, hematological, biochemical, serological, cytological, and polymerase chain reaction tests supporting the diagnosis have been performed.

Conclusion

To the best of our knowledge, this is the first report of A. platys from Bulgaria. This report adds to the overall knowledge of Anaplasma spp. in our country and the region of Southeastern Europe.

Association between Increased the De Ritis Quotient and Renal Azotaemia in Canine Babesiosis

Simple Summary

This study investigated the association between increased serum aspartate aminotransferase (AST) activity and renal indices such as renal failure index, sodium fractional excretion, and urinary creatinine to serum creatinine ratio in dogs with renal azotaemia infected with Babesia canis. This research revealed that increased serum AST activity in azotaemic dogs may be of renal origin, and the de Ritis quotient may be a convenient and useful tool in the recognition of renal azotaemia in canine babesiosis.

Abstract

Previous studies of azotaemia in canine babesiosis revealed pre-renal and renal azotaemia in infected dogs, and an association between an increased de Ritis quotient (aspartate aminotransferase to alanine aminotransferase activity; AST/ALT ratio) and azotaemia in affected animals. Serum activities of AST and ALT, and AST/ALT ratio were compared between azotaemic and non-azotaemic dogs infected with Babesia canis, and between affected dogs with pre-renal and renal azotaemia. Statistical analyses revealed higher AST activity and an increased AST/ALT ratio in azotaemic dogs, and an increase of these two parameters in infected dogs with renal azotaemia in comparison to dogs with pre-renal azotaemia. Moreover, AST activity and AST/ALT ratio were correlated with renal indices such as renal failure index, sodium fractional excretion, and urinary creatinine to serum creatinine ratio. The study also revealed a lack of correlation between AST and ALT activities in azotaemic dogs, although a correlation was observed when including all dogs in this study (azotaemic and non-azotaemic dogs treated as one group). The results of this study indicate that increased serum AST activity in azotaemic dogs infected with B. canis may have a renal origin, and the AST/ALT ratio could be considered as a simple and convenient renal index that is useful in the recognition of renal azotaemia in canine babesiosis.

Disorders in blood circulation as a probable cause of death in dogs infected with Babesia canis

Introduction

The purpose of the study was to investigate post-mortem changes in dogs infected with Babesia canis and to establish the probable cause of death of the affected animals.

Material and Methods

Cadavers of six dogs that did not survive babesiosis were collected. Necropsies were performed and samples of various organs were collected for histological examination.

Results

Necropsies and histological examinations revealed congestion and oedemata in various organs. Most of the dogs had ascites, hydrothorax or hydropericardium, pulmonary oedema, pulmonary, renal, hepatic, and cerebral congestion, and necrosis of cardiomyocytes.

Conclusion

These results suggested disorders in blood circulation as the most probable cause of death. However, the pulmonary inflammatory response and cerebral babesiosis observed in some of these dogs could also be considered possible causes of death. This study also showed a possible role for renal congestion in the development of renal hypoxia and azotaemia in canine babesiosis.

Wentzel J, Wills-Berriman S, Boni LD, Weyer J, Rossouw J, Oosthuizen MC. Anaplasma phagocytophilum and Other Anaplasma spp. in Various Hosts in the Mnisi Community, Mpumalanga Province, South Africa

DNA samples from 74 patients with non-malarial acute febrile illness (AFI), 282 rodents, 100 cattle, 56 dogs and 160 Rhipicephalus sanguineus ticks were screened for the presence of Anaplasma phagocytophilum DNA using a quantitative PCR (qPCR) assay targeting the msp2 gene. The test detected both A. phagocytophilum and Anaplasma sp. SA/ZAM dog DNA. Microbiome sequencing confirmed the presence of low levels of A. phagocytophilum DNA in the blood of rodents, dogs and cattle, while high levels of A. platys and Anaplasma sp. SA/ZAM dog were detected in dogs. Directed sequencing of the 16S rRNA and gltA genes in selected samples revealed the presence of A. phagocytophilum DNA in humans, dogs and rodents and highlighted its importance as a possible contributing cause of AFI in South Africa. A number of recently described Anaplasma species and A. platys were also detected in the study. Phylogenetic analyses grouped Anaplasma sp. SA/ZAM dog into a distinct clade, with sufficient divergence from other Anaplasma species to warrant classification as a separate species. Until appropriate type-material can be deposited and the species is formally described, we will refer to this novel organism as Anaplasma sp. SA dog.

First detection of Anaplasma ovis in sheep and Anaplasma platys-like variants from cattle in Menoufia governorate, Egypt

Tick-borne diseases are of global economic importance, especially due to the costs associated with disease treatment and productivity losses in livestock. In this study, 244 livestock animals (cattle N = 92, buffaloes N = 86 and sheep N = 66) from Menoufia, Egypt were tested for Anaplasma, Ehrlichia and Babesia species using PCR. Results revealed detection of A. ovis (9.1%) in sheep while Anaplasma spp. (14.1%), A. marginale (15.2%), B. bigemina (6.5%) and B. bovis (5.4%) in cattle. On the other hand, Anaplasma spp. (1.2%), A. marginale (1.2%) and B. bovis (1.2%), were detected in buffaloes. Significantly higher detection rates were observed in cattle for Anaplasma spp. (P = .020), A. marginale (P = .001) and B. bigemina (P = .022) than in buffaloes. Sequence analysis of Anaplasma spp. isolates from cattle, revealed A. platys-like strains. Phylogenetic analyses of the A. platys-like isolates revealed variation among the strains infecting cattle. The A. marginale buffalo isolate, on the other hand, showed some level of divergence from the cattle isolates. This study reports the first detection of A. ovis in sheep and A. platys-like strains in cattle in Menoufia and Egypt at large. The results of the current study provide valuable information on the epidemiology and genetic characteristics of tick-borne pathogens infecting livestock in Egypt.

Hyponatraemia and Syndrome of Inappropriate Antidiuretic Hormone Secretion in Non-azotaemic Dogs with Babesiosis Associated with Decreased Arterial Blood Pressure

Introduction

A previous study on canine babesiosis showed low serum tonicity in affected dogs, which may result from syndrome of inappropriate antidiuretic hormone secretion (SIADH). This endocrine disorder was recognised in human malaria which is considered a disease with similar pathogenesis to canine babesiosis. The aim of this study was to investigate the occurrence of SIADH in babesiosis-afflicted dogs.

Material and Methods

Serum and urinary sodium and urine specific gravity (USG) were determined in dogs with babesiosis. Mean arterial pressure (MAP) was measured at the beginning of the clinical examination. Serum tonicity and osmolality were calculated. Correlations were calculated between MAP and serum and urinary sodium concentrations, USG, serum tonicity, and calculated serum osmolality.

Results

Statistically significant correlations were observed between MAP and tonicity, calculated osmolality, USG, and serum and urinary sodium concentrations in non-azotaemic dogs. In three non-azotaemic dogs SIADH was recognised.

Conclusion

SIADH develops in non-azotaemic dogs with babesiosis. It is probably associated with decreased blood pressure in infected dogs. Thus, it seems that in fact it may be appropriate vasopressin secretion in canine babesiosis as a protective mechanism in hypotension which leads to hypoxia and renal failure in affected dogs.

Epidemiology, risk factors, and co-infection of vector-borne pathogens in goats from Sistan and Baluchestan province, Iran

Several vector-borne pathogens restrict livestock farming and have significant economic impact worldwide. In endemic areas livestock are exposed to different tick species carrying various pathogens which could result in co-infection with several tick-borne pathogens in a single host. Although the co-infection of and the interaction among pathogens are critical factors to determine the disease outcome, pathogen interactions in the vector and the host are poorly understood. In this study, we surveyed the presence of Babesia ovis, Theileria ovis, Theileria lestoquardi, Anaplasma ovis, Anaplasma phagocytophilum, and Anaplasma marginale in 200 goats from 3 different districts in Sistan and Baluchestan province, Iran. Species-specific diagnostic PCRs and sequence analysis revealed that 1.5%, 12.5%, and 80% of samples were positive for T. lestoquardi, T. ovis, and A. ovis, respectively. Co-infections of goats with up to 3 pathogens were seen in 22% of the samples. We detected a significant association between T. ovis infection and age, T. ovis infection and location (Zabol), and A. ovis infection and location (Sarbaz) by multivariate logistic regression analysis. In addition, by analyzing the data with respect to Plasmodium caprae infection in these goats, a negative correlation was found between P. caprae and A. ovis infection. This study contributes to understanding the epidemiology of vector-borne pathogens and their interplay in goats.

Molecular analysis of tick-borne protozoan and rickettsial pathogens in small ruminants from two South African provinces

Tick-borne protozoan and rickettsial diseases are a major threat to livestock in tropical and sub-tropical regions of Africa. In this study we investigated the presence and distribution of Theileria spp., Babesia ovis, Anaplasma ovis, Anaplasma phagocytophilum, Ehrlichia ruminantium and SFG Rickettsia in sheep and goats from Free State and KwaZulu-Natal provinces. A total of 91 blood samples were screened in this study, 61 from goats and 30 from sheep. PCR assay was conducted using primers based on Theileria spp. 18S rRNA, Babesia ovis (BoSSU rRNA), Anaplasma ovis (AoMSP4), Anaplasma phagocytophilum epank1, Ehrlichia ruminantium pCS20 and SFG Rickettsia OmpA. Overall infection rates of Theileria spp., Anaplasma ovis and Ehrlichia ruminantium were 18 (19.8%), 33 (36.3%) and 13 (14.3%), respectively. The co-infection of two pathogens were detected in 17/91 (18.7%) of all samples, goats having higher rates of co-infection compared to sheep. Phylogenetic tree analysis sequence of pCS20 gene of E. ruminantium of this study was found to be in the same clade with Kumm2 and Riverside strains both from South Africa. The phylogram of SSU rRNA of Theileria ovis had longer branch length compared to all other sequences most of which were from Asia and Middle East. This study provides important data for understanding the tick-borne diseases occurrence in the study area and it is expected to improve the approach for the diagnosis and control of these diseases.

Altitude-Dependent Prevalence of Canine Granulocytic Anaplasmosis in Romania

Canine granulocytic anaplasmosis (CGA) is an important tick-borne disease with worldwide distribution. The importance of this disease resides in the ability of Anaplasma phagocytophilum to infect humans and several animal species. The aim of the study was to evaluate the prevalence rate of CGA in different altitudinal areas of Romania. A total of 357 canine blood samples were collected during 2010-2013 from eight counties. To assess the influence of the altitude on A. phagocytophilum prevalence, the samples were collected from four different altitude areas (coastal 0-5 meters; lowland 6-100 meters; hilly areas 200-300 meters; low mountain areas >500 meters). These samples were evaluated for the presence of A. phagocytophilum DNA by amplifying part of the Ankyrin repeat protein (AnkA) gene. A higher prevalence was obtained for coastal compared with remaining areas, suggesting an influence of altitude on the CGA. Moreover, the results suggest an influence of climate and rainfall. In the present research work, we highlight the risk of granulocytic anaplasmosis in Central and Southern Romania, with a greater risk associated to Southern lowland region, especially in coastal areas. The importance of these results resides in the zoonotic potential of the canine A. phagocytophilum strains. In conclusion, the altitude and precipitation level may be risk factors for A. phagocytophilum infection in dogs and other hosts, including humans.

Molecular detection of Anaplasma phagocytophilum and Borrelia burgdorferi sensu lato genospecies in red foxes (Vulpes vulpes) from Romania

BACKGROUND

Red foxes (Vulpes vulpes) are one of the most widespread wild carnivores in the world, being recognized to harbor and transmit a wide range of vector-borne diseases. Anaplasma phagocytophilum and Borrelia burgdorferi sensu lato are zoonotic tick-borne pathogens causing emerging diseases. Wild animals play an essential role in the transmission of diseases and pathogens maintenance in nature. Epidemiological studies regarding the prevalence of tick-borne pathogens in red foxes are of public health importance, as they may successfully act as a pathogen transmission interface between wildlife, domestic animals and humans.

FINDINGS

This study included 14 counties from Romania. A total number of 353 red foxes (Vulpes vulpes) were examined. Heart tissue samples were collected during necropsy and stored at -20 °C. Genomic DNA extraction was performed and all samples were examined by polymerase chain reaction (PCR). Specific primers for A. phagocytophilum, A. platys, E. canis and Borrelia burgdorferi s.l. were used. Sequence analysis was performed (Macrogen Europe, Amsterdam) and obtained sequences are available at GenBank™. Out of the 353 samples, 9 (2.55 %; 95 % CI: 1.25-4.96 %) were positive for A. phagocytophilum. Positive animals originated from 5 counties. In total, 5 out of 353 heart tissue samples (1.42 %; 95 % CI: 0.52-3.47 %) collected from red foxes were positive for B. burgdorferi s.l. Red foxes originated from 4 counties. None of the samples were positive for A. platys or E. canis. No co-infection with A. phagocytophilum and B. burgdorferi s.l. was found.

CONCLUSION

This first report of A. phagocytophilum and B. burgdorferi s.l. in red foxes from Romania suggests a limited role of foxes in the maintenance of the two related pathogens, but may represent a potential risk from a public health perspective.

Low T3 syndrome in canine babesiosis associated with increased serum IL-6 concentration and azotaemia

Low triiodothyronine (T3) syndrome, also named euthyroid sick syndrome or non-thyroidal illness syndrome, has been recognized in canine babesiosis caused by Babesia rossi, where it manifested by lowering of the serum thyrotropin (TSH), total thyroxin (TT4) and free thyroxin (FT4) concentrations. This syndrome has also been observed in critical diseases in humans and animals, and the severity of the disease is considered an important factor in lowering of thyroid hormone concentrations. Interleukin-6 (IL-6) plays a role in the development of low T3 syndrome by causing a decrease in deiodinases 1 and 2 activity and increased activity of deiodinase 3, enzymes involved in the conversion of thyroxin (T4) to T3. The purpose of this study was to compare the concentrations of serum thyroid hormones and TSH between healthy dogs and dogs with babesiosis, and to determine correlations between serum IL-6 concentration and serum total T3 (TT3), TT4, FT4, and TSH concentrations, and the level of azotaemia in dogs with babesiosis. The concentrations of IL-6, TT3, TT4, FT4, TSH, urea and creatinine were determined in 13 dogs with canine babesiosis caused by Babesia canis and in 10 healthy dogs. The results of this study showed decreases in TT3, TT4, FT4, and TSH and increases in IL-6, urea and creatinine concentrations in affected dogs in comparison to healthy dogs. The concentration of IL-6 was negatively correlated with TT3 and TSH concentrations and the TT3 concentration was negatively correlated with serum urea and creatinine concentrations. This study showed low T3 syndrome in canine babesiosis, which was confirmed by the determination of the T3 concentration, and demonstrates that in canine babesiosis the T3 concentration is associated with IL-6 concentration.

Human granulocytic anaplasmosis in the United States from 2008 to 2012: a summary of national surveillance data

Human granulocytic anaplasmosis is an acute, febrile illness transmitted by the ticks Ixodes scapularis and Ixodes pacificus in the United States. We present a summary of passive surveillance data for cases of anaplasmosis with onset during 2008-2012. The overall reported incidence rate (IR) was 6.3 cases per million person-years. Cases were reported from 38 states and from New York City, with the highest incidence in Minnesota (IR = 97), Wisconsin (IR = 79), and Rhode Island (IR = 51). Thirty-seven percent of cases were classified as confirmed, almost exclusively by polymerase chain reaction. The reported case fatality rate was 0.3% and the reported hospitalization rate was 31%. IRs, hospitalization rates, life-threatening complications, and case fatality rates increased with age group. The IR increased from 2008 to 2012 and the geographic range of reported cases of anaplasmosis appears to have increased since 2000-2007. Our findings are consistent with previous case series and recent reports of the expanding range of the tick vector I. scapularis.

Anaplasma phagocytophilum in questing Ixodes ricinus ticks from Romania

Granulocytic anaplasmosis is a common vector-borne disease of humans and animals with natural transmission cycle that involves tick vectors, among which Ixodes ricinus is the most important. The present paper reports the prevalence and geographical distribution of A. phagocytophilum in 10,438 questing Ixodes ricinus ticks collected at 113 locations from 40 counties of Romania. The unfed ticks were examined for the presence of A. phagocytophilum by PCR targeting a portion of ankA gene. The overall prevalence of infection was 3.42%, with local prevalences ranging between 0.29% and 22.45%, with an average prevalence of 5.39% in the infected localities. The infection with A. phagocytophilum was detected in 72 out of 113 localities and in 34 out of 40 counties. The highest prevalence was recorded in females followed by males and nymphs. The results and the distribution model have shown a large distribution of A. phagocytophilum, covering Romania's entire territory. This study is the first large scale survey of the presence of A. phagocytophilum in questing I. ricinus ticks from Romania.

Chronic Lyme Disease and Co-infections: Differential Diagnosis

In Lyme disease concurrent infections frequently occur. The clinical and pathological impact of co-infections was first recognized in the 1990th, i.e. approximately ten years after the discovery of Lyme disease. Their pathological synergism can exacerbate Lyme disease or induce similar disease manifestations. Co-infecting agents can be transmitted together with Borrelia burgdorferi by tick bite resulting in multiple infections but a fraction of co-infections occur independently of tick bite. Clinically relevant co-infections are caused by Bartonella species, Yersinia enterocolitica, Chlamydophila pneumoniae, Chlamydia trachomatis, and Mycoplasma pneumoniae. In contrast to the USA, human granulocytic anaplasmosis (HGA) and babesiosis are not of major importance in Europe. Infections caused by these pathogens in patients not infected by Borrelia burgdorferi can result in clinical symptoms similar to those occurring in Lyme disease. This applies particularly to infections caused by Bartonella henselae, Yersinia enterocolitica, and Mycoplasma pneumoniae. Chlamydia trachomatis primarily causes polyarthritis. Chlamydophila pneumoniae not only causes arthritis but also affects the nervous system and the heart, which renders the differential diagnosis difficult. The diagnosis is even more complex when co-infections occur in association with Lyme disease. Treatment recommendations are based on individual expert opinions. In antibiotic therapy, the use of third generation cephalosporins should only be considered in cases of Lyme disease. The same applies to carbapenems, which however are used occasionally in infections caused by Yersinia enterocolitica. For the remaining infections predominantly tetracyclines and macrolides are used. Quinolones are for alternative treatment, particularly gemifloxacin. For Bartonella henselae, Chlamydia trachomatis, and Chlamydophila pneumoniae the combination with rifampicin is recommended. Erythromycin is the drug of choice for Campylobacter jejuni.

Wild boars as hosts of human-pathogenic Anaplasma phagocytophilum variants

To investigate the potential of wild boars to host Anaplasma phagocytophilum, we analyzed bacterial 16S rRNA and ank genes. DNA sequencing identified several A. phagocytophilum variants, including a predominance of strains known to cause human disease. Boars are thus hosts for A. phagocytophilum, notably, strains associated with human granulocytic anaplasmosis.

Detection of the DNA of Borrelia afzelii, Anaplasma phagocytophilum and Babesia canis in blood samples from dogs in Warsaw

Each month, from March 2003 to February 2004, 34 blood samples from dogs were randomly selected from the blood samples delivered to two veterinary laboratories in Warsaw and tested for the DNA of Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, Babesia canis and Hepatozoon canis. Borrelia DNA was detected in seven of the 408 dogs, A phagocytophilum DNA was found in two, and B canis DNA was found in 48 (11.8 per cent). The DNA of H canis was not found in any of the blood samples. Sequencing of the seven Borrelia amplicons showed that only the genospecies Borrelia afzelii was present, the first time it has been detected in dogs in Poland.

Larvae of chigger mites Neotrombicula spp. (Acari: Trombiculidae) exhibited Borrelia but no Anaplasma infections: a field study including birds from the Czech Carpathians as hosts of chiggers

Chigger mites were collected from 1,080 wild birds of 37 species at Certak (Czech Republic), in the western Carpathian Mountains, from 29 July to 24 September 2005. The prevalence of infestation with chigger larvae was 7%. A total of 325 chigger specimens from 10 bird species was identified and three chigger species were found: Neotrombicula autumnalis, N. carpathica, and N. inopinata, the latter two species being reported on new hosts. Neotrombicula carpathica is reported in the Czech Republic for the first time. A total of 509 chigger larvae found on 79 host specimens were examined by polymerase chain reaction (PCR) for the presence of Borrelia burgdorferi s.l. DNA (fragments of the rrf (5S)--rrl (23S) intergenic spacer), and Anaplasma phagocytophilum DNA (epank1 gene). A fragment of specific Borrelia DNA was amplified through PCR in one sample, and the PCR product was further analyzed by reverse line blotting assay, whereby both genospecies of B. garinii and B. valaisiana were proved. This sample pooled five chigger larvae collected from one Sylvia atricapilla on 11 August 2005. No A. phagocytophilum DNA was amplified. We conclude that larvae of the genus Neotrombicula can be infected with Borrelia genospecies originated from their present or former hosts.

Prevalence of Babesia canis, Borrelia afzelii, and Anaplasma phagocytophilum infection in hard ticks removed from dogs in Warsaw (central Poland)

The purposes of this study were to specify the occurrence and prevalence of Babesia canis, Borrelia burgdorferi sensu lato, and Anaplasma phagocytophilum in ticks removed from dogs in Warsaw, and to determine the Borrelia species occurring in Ixodes ricinus ticks. Among 590 collected ticks, 209 were identified as I. ricinus, and 381 as Dermacentor reticulatus. DNA of B. canis was detected in 11% of D. reticulatus ticks. We found that 6.2% of I. ricinus ticks harbored B. burgdorferi s.l. specific DNA and 2.9% harbored A. phagocytophilum DNA. In these samples sequencing of the detected Borrelia amplicon confirmed infection with Borrelia afzelii genospecies. New sequences were submitted to the GenBank database (accession no. EU152128, EU152127, EU152126). This work is the first detection of B. afzelii and A. phagocytophilum in ticks from Warsaw, and the first survey for the prevalence of B. canis, B. afzelii, and A. phagocytophilum in ticks in central Poland.

Contribution of polymorphisms in ankA, gltA, and groESL in defining genetic variants of Anaplasma phagocytophilum

Analysis of several nucleotide polymorphisms in polymorphic genes (ankA, gltA, and groESL) from 16S rRNA gene-based genetic variants of Anaplasma phagocytophilum from dogs in the western United States defined at least two sets of multigene polymorphisms to further characterize these variants. The multigene polymorphism approach holds promise for development of a genotyping scheme for this important pathogen.

Immune-mediated haemolytic anaemia and thrombocytopenia associated with Anaplasma phagocytophilum in a dog

A 10-year-old, crossbreed dog was presented with a history of severe lethargy, pyrexia and inappetence of several days' duration. Clinical examination revealed pallor of the mucous membranes, petechiae, generalised lymphadenopathy and effusions in multiple joints. Laboratory evaluation showed severe anaemia and thrombocytopenia, with positive in-saline agglutination and the presence of antiplatelet antibodies. The DNA of Anaplasma phagocytophilum, an endemic granulocytic rickettsial parasite, was detected by PCR. A poor response to doxycycline and immunosuppressive therapy with corticosteroids was seen. Euthanasia was performed after the development of disseminated intravascular coagulation. Postmortem examination demonstrated changes consistent with the development of disseminated intravascular coagulation and infection with granulocytic ehrlichiosis. This case documents the presence of canine granulocytic ehrlichiosis caused by A phagocytophilum in the U.K., and highlights the range of clinical signs and clinicopathological abnormalities that may be observed in infected dogs.

A real-time combined polymerase chain reaction assay for the rapid detection and differentiation of Anaplasma phagocytophilum, Ehrlichia chaffeensis, and Ehrlichia ewingii

A rapid real-time polymerase chain reaction (PCR) assay capable of the simultaneous detection and differentiation of Anaplasma phagocytophilum, Ehrlichia chaffeensis, and Ehrlichia ewingii was developed using the LightCyclertrade mark instrument (Roche Applied Sciences, Indianapolis, IN). The assay targets the operon groEL of the heat shock protein. Base pair mismatches in amplified DNA in regions of detection probe hybridization allowed organism differentiation by melting curve analysis. The analytical sensitivity was at least 10 copies per reaction. DNA extracts from 59 specimens previously confirmed positive for A. phagocytophilum (n = 37), E. chaffeensis (n = 19), or E. ewingii (n = 3) were used to evaluate the assay. All of the specimens positive for 1 of the 3 organisms by conventional PCR were likewise positive by the LightCycler method. Sensitivity and specificity were at least 100% compared with conventional PCR. This assay provides a rapid method for the detection and differentiation of the causative agents of human ehrlichiosis in the United States.

First detection of Anaplasma phagocytophilum in quill mites (Acari: Syringophilidae) parasitizing passerine birds

Forest passerine birds and their ectoparasites: Ixodes ricinus ticks and Syringophilidae quill mites were surveyed for infection with Anaplasma phagocytophilum in west-central Poland. Of 126 birds captured from May to June of 2002, 71 (56.3%) comprising eight species, hosted immature I. ricinus ticks. A total of 383 ticks and 71 blood samples collected from tick-infested birds were investigated by PCR. The pathogen was not detected in either bird-derived ticks or in blood samples. Among the captured birds, a total of 14 individuals representing four species hosted quill mites from the family Syringophilidae. Three of the 14 mite pools recovered from the 14 mite-infested birds harbored A. phagocytophilum DNA by amplifying both the epank1 and p44 gene. The PCR-positive pools originated from one blackbird and two starlings. The specific biology of syringophilid mites, which parasitize exclusively inside the quill of feathers, feeding on host subcutaneous fluids, implies that they must have acquired the pathogen from a bacteremic bird. These results provide the first indirect evidence that at least some passerine hosts are prone to develop systemic infection with A. phagocytophilum under natural conditions. Consequently, the infected quill mites may serve as a "biological marker" of past or current infection with the agent within birds.

Ehrlichiosis y anaplasmosis humana

Human ehrlichiosis and anaplasmosis are acute febrile tick-borne diseases caused by various species of the genera Ehrlichia and Anaplasma (Anaplasmataceae). To date, only cases of human granulocytic anaplasmosis (HGA) caused by Anaplasma phagocytophilum (formerly human granulocytic Ehrlichia, Ehrlichia phagocytophila, and E. equi) have been diagnosed in Europe. HGA and Lyme borreliosis are closely related diseases that share vector and reservoirs. In addition to HGA, human monocytic ehrlichiosis caused by E. chaffeensis has been reported in North America, as well as cases of infection due to E. ewingii in immunocompromised hosts. Ehrlichia spp. and A. phagocytophilum have tropism for blood cells, especially leukocytes and platelets, causing a considerable decrease of both components in these patients. HGA should be suspected in tick-bitten patients or those who have visited an endemic area and show symptoms of flu-like fever, leukopenia and thrombocytopenia.

Guidelines for the diagnosis of tick-borne bacterial diseases in Europe

Ticks are obligate haematophagous acarines that parasitise every class of vertebrate (including man) and have a worldwide distribution. An increasing awareness of tick-borne diseases among clinicians and scientific researchers has led to the recent description of a number of emerging tick-borne bacterial diseases. Since the identification of Borrelia burgdorferi as the agent of Lyme disease in 1982, 11 tick-borne human bacterial pathogens have been described in Europe. Aetiological diagnosis of tick-transmitted diseases is often difficult and relies on specialised laboratories using very specific tools. Interpretation of laboratory data is very important in order to establish the diagnosis. These guidelines aim to help clinicians and microbiologists in diagnosing infection transmitted by tick bites and to provide the scientific and medical community with a better understanding of these infectious diseases.

Multiplex real-time PCR for detection of anaplasma phagocytophilum and Borrelia burgdorferi

A multiplex real-time PCR assay was developed for the simultaneous detection of Anaplasma phagocytophilum and Borrelia burgdorferi. The assay was tested on various Anaplasma, Borrelia, Erhlichia, and Rickettsia species, as well as on Bartonella henselae and Escherichia coli, and the assay was found to be highly specific for A. phagocytophilum and the Borrelia species tested (B. burgdorferi, B. parkeri, B. andersonii, and B. bissettii). The analytical sensitivity of the assay is comparable to that of previously described nested PCR assays (A. phagocytophilum, 16S rRNA; B. burgdorferi, fla gene), amplifying the equivalent of one-eighth of an A. phagocytophilum-infected cell and 50 borrelia spirochetes. The dynamic range of the assay for both A. phagocytophilum and B. burgdorferi was >/=4 logs of magnitude. Purified DNA from A. phagocytophilum and B. burgdorferi was spiked into DNA extracted from uninfected ticks and from negative control mouse and human bloods, and these background DNAs were shown to have no significant effect on sensitivity or specificity of the assay. The assay was tested on field-collected Ixodes scapularis ticks and shown to have 100% concordance compared to previously described non-probe-based PCR assays. To our knowledge, this is the first report of a real-time multiplex PCR assay that can be used for the simultaneous and rapid screening of samples for A. phagocytophilum and Borrelia species, two of the most common tick-borne infectious agents in the United States.

Diagnosis of human granulocytic ehrlichiosis: state of the art

Human granulocytic ehrlichiosis is an emerging zoonosis caused by Anaplasma phagocytophilum and transmitted through the bite of infected Ixodes scapularis. It is prevalent in the Midwest and Northeast United States and also in Europe, and it presents as a nonspecific febrile illness a few days after a tick bite usually between late spring and fall. Most cases present in adult patients with a mild form of the disease, although it can be severe with multiorgan failure, particularly in the elderly and in the immunocompromised. Routine laboratory abnormalities include leukopenia with a left shift, lymphopenia, and thrombocytopenia. These abnormalities are more frequently present during the first week of illness and then tend to normalize; therefore their absence should not exclude the diagnosis. Specific tests to confirm the diagnosis during the acute phase include microscopic detection of morulae in granulocytes, culture of A. phagocytophilum, and polymerase chain reaction. Of these methods, culture appears to have the greatest sensitivity during the acute phase prior to antimicrobial treatment. Serology has an important role in the confirmation of the diagnosis when used in paired specimens and when high cutoff titers by indirect fluorescence antibody assay (> or = 640) are used to diagnose a recent infection.

Molecular methods for ehrlichiosis and Lyme disease

This article reviews molecular techniques that have been developed and are effective in the clinical laboratory for the emerging tick-borne infections, ehrlichiosis and Lyme disease.

Identification of Ehrlichia chaffeensis, Anaplasma phagocytophilum, and A. bovis in Haemaphysalis longicornis and Ixodes persulcatus ticks from Korea

A total of 1,467 tick (1,463 of Haemaphysalis longicornis, three of Ixodes persulcatus and one of I. turdus) collected from nine provinces of Korea were examined by TaqMan real-time PCR for the presence of Ehrlichia and Anaplasma species. One set of primers and a probe were designed for detection of all of the Ehrlichia and Anaplasma species. Template DNAs (total 803) were prepared either from pools of larvae, nymphs, adult males and females, or from the salivary gland and midgut of adult ticks. Only DNAs positive in TaqMan PCR were examined for A. phagocytophilum with nested PCR and for E. chaffeensis with PCR. Four A. phagocytophilum 16S rRNA gene PCR products were sequenced for comparison with sequences previously reported. Amplification of a 16S rRNA gene fragment of Ehrlichia and Anaplasma species was observed in 364 tick DNAs (45.3% of the total). Of these 364 positive ticks, species-specific PCRs confirmed that 35 H. longicornis and one I. persulcatus were positive for A. phagocytophilum and one I. persulcatus was positive in E. chaffeensis. Except for one (AB-GGHL, GenBank accession number [GAN] AF470698), three of the four 16S rRNA gene fragment sequences of the A. phagocytophilum-positive samples were similar or identical to the sequences of variants of A. phagocytophilum deposited in GenBank. The 16S rRNA gene fragment sequence of AB-GGHL was similar to that of Anaplasma (Ehrlichia) bovis 16S rRNA (GAN U03775). The identities of the Anaplasmataceae genus and species DNA in the 327 ticks that could not be confirmed infected with either E. chaffeensis, A. phagocytophilum, or A. bovis are not known. This study is the first to demonstrate the presence of E. chaffeensis, A. phagocytophilum and A. bovis in Korean ticks.

Serotyping isolates of Anaplasma phagocytophilum by using monoclonal antibodies

Ten mouse monoclonal antibodies (MAbs) that react with Anaplasma phagocytophilum (the human granulocytic ehrlichiosis agent) Webster isolates were developed. Seven different isolates of A. phagocytophilum were subtyped with these MAbs. Western blot analysis revealed that these MAbs reacted mainly with 41- to 46-kDa Msp2 proteins. Six MAbs reacted with all isolates. Four other MAbs reacted with human isolates from Wisconsin, but not with human isolates from New York or with animal isolates. Three different serotypes were identified. These features may lead to the development of other specific MAbs in order to provide tools for antigenic characterization of human isolates of A. phagocytophilum.

Human Granulocytic Ehrlichiosis in Belgium: an underestimated cause of disease

OBJECTIVES

Human Granulocytic Ehrlichiosis (HGE) is a recently discovered zoonosis and, in Europe, not always included in laboratory testing when a patient presents with a history of tick bite. The available serology results indicate that HGE should be included in the screening panel when a tick-borne disease is suspected.

METHODS

Serological methods were applied; i.e. indirect immunofluorescence and Western Blot analysis. Sixty-five serum samples from 47 patients were analysed, of six patients sequential samples were available.

RESULTS

33.8% of the submitted samples were found positive in indirect immunofluorescence, Western Blot confirmed 46.1% of these positive samples.

CONCLUSIONS

Although the causative agent and the vector for HGE, Ixodes ticks, are present in Belgium, serology for HGE is seldom solicited. Ehrlichiosis is apparently not always considered as a plausible or possible cause for illness, even when the patient presents with a history of tick bite. We present here a, true be it, incomplete picture of the present situation in Belgium, but nevertheless indicating that it is warranted to test patients with a history of tick bite not only for Lyme disease, but also for HGE.

Comparison of PCR assays for detection of the agent of human granulocytic ehrlichiosis, Anaplasma phagocytophilum

Human granulocytic ehrlichiosis is an emerging infectious disease in the United States and Europe, and PCR methods have been shown to be effective for the diagnosis of acute infections. Numerous PCR assays and primer sets have been reported in the literature. The analytical sensitivities (limits of detection) of 13 published PCR primer sets were compared using DNA extracted from serial dilutions of Anaplasma phagocytophilum-infected HL-60 cells. The specificity of the assays that were able to detect <or=2.5 infected cells was tested by the use of template DNA extracted from Ehrlichia chaffeensis, Rickettsia rickettsii, and Bartonella henselae. The assays with the lowest limits of detection were shown to be a nested assay that amplifies the 16S rRNA gene (primer pairs ge3a-ge10 [primary] and ge9-ge3 [nested]; detects 0.25 infected cell), a direct assay that amplifies the major surface protein gene msp2 (primer pair msp2-3f-msp2-3r; detects 0.25 infected cell), and a direct assay that amplifies the 16S rRNA gene (primer pair ehr521-ehr790; detects 0.25 infected cell). The specificity and limit of detection of the MSP2 and 16S rRNA direct assays were further tested by use of A. phagocytophilum template DNA from both North America and Europe and from human, tick, white-footed mouse, equine, deer, bovine, and wood rat samples and of template DNA from closely related species (Anaplasma marginale, the white-tailed deer agent, and additional E. chaffeensis-positive samples). Three manufacturers' PCR kits were tested and showed distinct variations in the limit of detection, specificity, and nonspecific background amplification. The importance of these results for the molecular diagnosis of human granulocytic ehrlichiosis is discussed.

Prevalence of granulocytic Ehrlichia and Borrelia burgdorferi sensu lato in Ixodes ricinus ticks collected from Southwestern Finland and from Vormsi Island in Estonia

Altogether, 343 adult and 111 nymphal Ixodes ricinus ticks collected from parks in Turku and suburban and rural islands of the Turku archipelago, Finland, and 100 adult I. ricinus ticks collected from Vormsi Island, Estonia, were included in this study. Using the polymerase chain reaction the ticks were examined for 16S rDNA of the Ehrlichia phagocytophila genogroup and for Borrelia burgdorferi sensu lato recA and flagellin genes. None of the Finnish ticks was found to be infected with E. phagocytophila, whereas 3% of the Estonian ticks were positive for this organism. The rate of Finnish ticks infected with B. burgdorferi sensu lato varied from 0% to 11.6% (mean 5%; 9% for adult and 4% for nymphal ticks). The corresponding rate for Estonian ticks was 15%. Borrelia afzelii was the most common genospecies in both Finnish (2.6%) and Estonian (12%) ticks. B. burgdorferi sensu stricto was detected in 2.0% of the Finnish ticks, but in none of the Estonian ticks. These results suggest that the E. phagocytophila genogroup is very rare in Finnish ticks, although the ticks were collected from an area endemic for Lyme borreliosis. In Estonia, E. phagocytophila is found in ticks and may cause disease.

High prevalence of granulocytic Ehrlichiae and Borrelia burgdorferi sensu lato in Ixodes ricinus ticks from Bulgaria

Bulgarian Ixodes ricinus ticks were examined for Ehrlichia and Borrelia coinfection: 34 and 32% of adult ticks and at least 2 and 10% of nymphs were positive for these infections, respectively. Coinfections and dual or triple Borrelia infections were frequent, although Ehrlichia phagocytophila heterogeneity was minimal. Multiple tick-borne bacteria coexist in I. ricinus ticks in southeastern Europe.

Citrate synthase gene sequence: a new tool for phylogenetic analysis and identification of Ehrlichia

The sequence of the citrate synthase gene (gltA) of 13 ehrlichial species (Ehrlichia chaffeensis, Ehrlichia canis, Ehrlichia muris, an Ehrlichia species recently detected from Ixodes ovatus, Cowdria ruminantium, Ehrlichia phagocytophila, Ehrlichia equi, the human granulocytic ehrlichiosis [HGE] agent, Anaplasma marginale, Anaplasma centrale, Ehrlichia sennetsu, Ehrlichia risticii, and Neorickettsia helminthoeca) have been determined by degenerate PCR and the Genome Walker method. The ehrlichial gltA genes are 1,197 bp (E. sennetsu and E. risticii) to 1,254 bp (A. marginale and A. centrale) long, and GC contents of the gene vary from 30.5% (Ehrlichia sp. detected from I. ovatus) to 51.0% (A. centrale). The percent identities of the gltA nucleotide sequences among ehrlichial species were 49.7% (E. risticii versus A. centrale) to 99.8% (HGE agent versus E. equi). The percent identities of deduced amino acid sequences were 44.4% (E. sennetsu versus E. muris) to 99.5% (HGE agent versus E. equi), whereas the homology range of 16S rRNA genes was 83.5% (E. risticii versus the Ehrlichia sp. detected from I. ovatus) to 99.9% (HGE agent, E. equi, and E. phagocytophila). The architecture of the phylogenetic trees constructed by gltA nucleotide sequences or amino acid sequences was similar to that derived from the 16S rRNA gene sequences but showed more-significant bootstrap values. Based upon the alignment analysis of the ehrlichial gltA sequences, two sets of primers were designed to amplify tick-borne Ehrlichia and Neorickettsia genogroup Ehrlichia (N. helminthoeca, E. sennetsu, and E. risticii), respectively. Tick-borne Ehrlichia species were specifically identified by restriction fragment length polymorphism (RFLP) patterns of AcsI and XhoI with the exception of E. muris and the very closely related ehrlichia derived from I. ovatus for which sequence analysis of the PCR product is needed. Similarly, Neorickettsia genogroup Ehrlichia species were specifically identified by RFLP patterns of RcaI digestion. If confirmed this technique will be useful in rapidly identifying Ehrlichia spp.

Serodiagnosis of human granulocytic ehrlichiosis by using novel combinations of immunoreactive recombinant proteins

A panel of seven recombinant antigens, derived from Ehrlichia phagocytophila (the agent of human granulocytic ehrlichiosis), was evaluated by class-specific enzyme-linked immunosorbent assays (ELISAs) for utility in the diagnosis of the infection. Fourteen genomic fragments, obtained by serologic expression screening, contained open reading frames (ORFs) encoding 16 immunodominant antigens. Eleven of these antigens were members of the major surface protein (MSP) multigene family. Alignment of their predicted protein sequences revealed a pattern of conserved sequences, which contained short direct repeats, flanking a variable region. In addition, two genomic clones contained two and three MSP ORFs, respectively, indicating that these genes are clustered in tandem copies. The implications for this pattern of both genomic and protein arrangements in antigenic variations of MSPs and in their utilities in a diagnostic assay are discussed. In addition to two MSP recombinant antigens (rHGE-1 and -3) and a fusion protein of these antigens (rErf-1), five further recombinants were evaluated by ELISA. Two of these antigens (rHGE-14 and -15) were novel, while a third (rHGE-2), with no known function, has been described. The final two recombinant antigens (rHGE-9 and -17) represent overlapping segments of the ankyrin gene (ank). The addition of rHGE-9 ELISA data resulted in the detection of 78% (21 of 27) of acute-phase sera. When serologic data for all recombinants are combined, 96.2% (26 of 27) of convalescent-phase patient serum samples and 85.2% (23 of 27) of acute-phase patient serum samples are detected, indicating the potential of these antigens for use in the development of a rapid serologic assay for the detection of E. phagocytophila infection.