Transmission of 'Candidatus Anaplasma camelii' to mice and rabbits by camel-specific keds, Hippobosca camelina.

Anaplasmosis, caused by infection with bacteria of the genus Anaplasma, is an important veterinary and zoonotic disease. Transmission by ticks has been characterized but little is known about non-tick vectors of livestock anaplasmosis. This study investigated the presence of Anaplasma spp. in camels in northern Kenya and whether the hematophagous camel ked, Hippobosca camelina, acts as a vector. Camels (n = 976) and > 10,000 keds were sampled over a three-year study period and the presence of Anaplasma species was determined by PCR-based assays targeting the Anaplasmataceae 16S rRNA gene. Camels were infected by a single species of Anaplasma, 'Candidatus Anaplasma camelii', with infection rates ranging from 63-78% during the dry (September 2017), wet (June-July 2018), and late wet seasons (July-August 2019). 10-29% of camel keds harbored 'Ca. Anaplasma camelii' acquired from infected camels during blood feeding. We determined that Anaplasma-positive camel keds could transmit 'Ca. Anaplasma camelii' to mice and rabbits via blood-feeding. We show competence in pathogen transmission and subsequent infection in mice and rabbits by microscopic observation in blood smears and by PCR. Transmission of 'Ca. Anaplasma camelii' to mice (8-47%) and rabbits (25%) occurred readily after ked bites. Hence, we demonstrate, for the first time, the potential of H. camelina as a vector of anaplasmosis. This key finding provides the rationale for establishing ked control programmes for improvement of livestock and human health.

Seasonal dynamics of Anaplasma spp. in goats in warm-temperate zone of China.

Anaplasma are tick-borne obligate intracellular bacteria that can endanger human and animal health, and until now, there have been few reports on the seasonal dynamics of Anaplasma species in China. In this study, a total of 491 goat blood samples were collected in spring (n = 124), summer (n = 135), autumn (n = 110), and winter (n = 122) from Shaanxi provinces. Single and mixed infections of Anaplasma spp. from warm-temperate regions of China were analyzed according to seasons using a nested PCR method. Positive samples were sequenced to observe the molecular and phylogenetic characteristics of the Anaplasma species, and we determined the co-infection rates of Anaplasma spp. for each season. A molecular survey of Anaplasma phagocytophilum, A. bovis, A. ovis, and A. capra in goats showed average prevalences of 71.6 % (maximum 86.7 % in summer and minimum 48.4 % in winter), 62.2 % (minimum 38.7 % in spring and maximum 94.1 % in summer), 25.5 % (minimum 0% in summer and maximum 51.6 % in spring), and 26.6 % (minimum 8.2 % in winter and maximum 55.6 % in summer), respectively. In the phylogenetic analysis, A. phagocytophilum and A. capra occupied two separate groups, Chinese A. bovis and foreign isolates appeared to be geographically isolated, and all A. ovis isolates were in the same branch as the previously described sequences. The survey indicated that goats in warm-temperate regions of China are frequently exposed to Anaplasma spp. all year round, and thus prevention and treatment efforts for anaplasmosis in the region should be strengthened.

Vector competence of Rhipicephalus sanguineus sensu stricto for Anaplasma platys.

Anaplasma platys is a Gram-negative, obligate intracellular bacteria that causes canine infectious cyclic thrombocytopenia in dogs. The brown dog tick Rhipicephalus sanguineus sensu lato is presumed to be the vector of A. platys based on the overlap in distribution of R. sanguineus and A. platys infections, detection of A. platys DNA in both flat and engorged field-collected R. sanguineus, and the fact that dogs are primary hosts of both brown dog ticks and A. platys. However, the only study evaluating the vector competence of R. sanguineus for A. platys under controlled laboratory conditions reported an apparent inability of ticks to acquire or maintain the pathogen. In 2016, engorged female Rhipicephalus sanguineus sensu stricto ticks were collected off dogs to start a laboratory tick colony. After one generation of colony maintenance on tick-naïve and pathogen-free New Zealand White rabbits, a rabbit used to feed F1 adults seroconverted to Anaplasma phagocytophilum antigen. PCR and subsequent DNA sequencing identified the presence of A. platys in both the adult ticks fed on this rabbit and their resulting F2 progenies. Retrospective testing of all previous (P and F1) life stages of this colony demonstrated that the infection originated from one field-collected A. platys-infected female whose progeny was propagated in the laboratory and produced the PCR-positive F1 adults. Over the following (F2-F4) generations, the prevalence of A. platys in this colony reached 90-100 % indicating highly efficient transovarial and horizontal transmission, as well as transstadial maintenance, of this pathogen by R. sanguineus s.s.

The co-infection with Ehrlichia minasensis, Anaplasma marginale and Anaplasma platys is not associated with anemia in beef cattle in the Brazilian Pantanal.

The Anaplasmataceae family is composed of obligatory intracellular Gram-negative bacteria transmitted by arthropod vectors. In Brazil, with the exception of Anaplasma marginale, little is known about the occurrence of other Anaplasma and Ehrlichia species infecting cattle. The present study aimed at investigating the occurrence of Anaplasma spp. and Ehrlichia spp. in beef cattle (Bos indicus) sampled in the Brazilian Pantanal, an area prone to periodic flooding and endemic for bovine trypanosomiasis. Blood samples from 400 cattle were collected and screened by PCR assays based on rrs and dsb genes from Anaplasma spp. and Ehrlichia spp., respectively. Positive samples for Anaplasma spp. were subjected to qPCR assays based on the msp-2 gene and nPCR based on the groEL gene. As a result, 4.75% (19/400) and 48.12% (167/347) were positive for Anaplasma platys and Ehrlichia minasensis, respectively. Besides, positivity of 56.75% (227/400) for A. marginale and seropositivity of 90.75% (363/400) for Trypanosoma vivax were found. A high rate of co-infection was observed (67.25%), from which the co-infection by A. marginale and E. minasensis was more frequently found in calves than cows. Interestingly, none of the animals presenting co-infection showed anemia or other clinical signs. The present study showed, for the first time, the occurrence of A. platys and E. minasensis in beef cattle in the southern Pantanal, as well as a high rate of co-infection by A. marginale, E. minasensis and T. vivax in the sampled animals.

First Report on Molecular Characterization of Anaplasmosis in Small Ruminants in Pakistan.

Anaplasmosis is caused by a Gram-negative obligate intracellular bacterium of the genus Anaplasma with the pathogen having a zoonotic impact. The study aimed to estimate the prevalence of anaplasmosis in Pakistan, to unravel the association of potential risk factors, and to investigate the effect on hematological parameters in affected small ruminants. A total of 150 (n = 75 sheep; n = 75 goats) blood samples were initially screened microscopically and then subjected to PCR targeting the amplification of the 16S rRNA gene fragment of Anaplasma. The PCR-based positive samples were then processed for sequencing. Statistical analysis regarding risk factors was performed using R software. The study revealed an overall 29.33% (44/150) prevalence of anaplasmosis in small ruminants. Sheep had higher (P > 0.05) prevalence (32%) as compared to goats (25.30%). The final statistical model resulting from backward elimination showed only tick infestation as a significant predictor of infection status. The phylogenetic analysis of 16S rRNA gene of Anaplasma spp. revealed 9 study isolates clustered together and showed a close resemblance (99%) with Anaplasma ovis isolate (DQ837600) from Hungary. One of the isolates showed (99%) similarity with the isolate of Anaplasma marginale (MH155594) from Iraq. Furthermore, the hematological parameters pack cell volume, red blood cells, hemoglobin, white blood cells, granulocytes, monocytes, lymphocytes, and platelet count were decreased in Anaplasma-positive animals. This is the first study at the molecular level to characterize Anaplasma spp. in small ruminants of Pakistan, and it will be useful in developing control strategies for anaplasmosis.

Molecular identification of Ehrlichia, Anaplasma, Babesia and Theileria in African elephants and their ticks.

Although historical records indicate the presence of Ehrlichia and Babesia in African elephants, not much is known about their prevalence and diversity in elephants and their ticks, Amblyomma thollonii and Rhipicephalus humeralis. We amplified and sequenced the hypervariable V4 region of the 18S rRNA gene of Babesia and Theileria and the heat shock protein gene (groEL) of Ehrlichia/Anaplasma in DNA extracted from elephant blood (n = 104) and from elephant ticks (n = 52). Our results showed that the African elephants were infected with a novel Babesia spp. while A. thollonii was infected with Theileria bicornis and Theileria cf. velifera. This is the first record of T. bicornis; a protozoan that is linked to fatal infection in rhinoceros in a tick. Elephants and their ticks were all infected with a species of Ehrlichia like that identified in Japanese deer. The prevalence of Babesia spp., Theileria spp. and Ehrlichia spp. in ticks was higher than that of their elephant hosts. About 13.5% of elephants were positive for Theileria or Babesia while 51% of A. thollonii ticks and 27% of R. humeralis ticks were positive for Theileria or Babesia. Moreover, 5.8% of elephants were positive for Ehrlichia or Anaplasma compared to 19.5% in A. thollonii and 18% in R. humeralis. There was no association between the positive result in ticks and that of their elephant hosts for either Babesia spp., Theileria spp. or Ehrlichia spp. Our study reveals that the African elephants are naturally infected with Babesia spp and Ehrlichia spp and opens up an opportunity for further studies to determine the role of elephant as reservoirs of tick-borne pathogens, and to investigate their potential in spreading these pathogens as they range extensively. The presence of T. bicornis in A. thollonii also suggests a need for experiments to confirm its vector competence.

Epidemiology and Diversity of Rickettsiales Bacteria in Humans and Animals in Jiangsu and Jiangxi provinces, China.

Diseases caused by Rickettsiales bacteria are a global public health problem. To better understand the diversity and origins of Rickettsiales infection in humans and animals, we sampled 134 febrile patients, 173 rodents and 43 shrews, as well as 358 ticks, from two cities in Jiangsu and Jiangxi provinces, China. Our data revealed a relatively high prevalence of scrub typhus cases in both localities. In addition, both serological tests and genetic analysis identified three patients infected with Anaplasma bovis, Rickettsia monacensis, and Orientia tsutsugamushi bacteria. Molecular epidemiological investigation revealed the co-circulation of multiple species of Rickettsiales bacteria in small mammals and ticks in both provinces, potentially including novel bacterial species. In sum, these data demonstrate the ongoing importance of Rickettsiales infection in China and highlight the need for the regular surveillance of local arthropods, mammals and humans.

A molecular survey of Anaplasma, Ehrlichia, Bartonella and Theileria in ticks collected from southeastern China.

To investigate the prevalence of Anaplasma, Ehrlichia, Bartonella and Theileria, we collected ticks from small mammals in six counties of Zhejiang Province in southeastern China. Polymerase chain reaction (PCR) amplification was performed to test Anaplasma, Ehrlichia, Bartonella and Theileria in tick samples. Positive PCR products were sequenced and then compared with previously published sequences deposited in GenBank using BLAST. About 292 adult ticks were captured and the dominant tick species were Ixodes sinensis and Haemaphysalis longicornis. Overall, 34 ticks (11.6%) were tested positive for at least one pathogen of Anaplasma, Ehrlichia, Bartonella and Theileria. Rates of PCR-positivity to Anaplasma, Ehrlichia, Bartonella and Theileria were 5.5, 1.7, 2.4 and 2.4%, respectively. Positive rates of Anaplasma, Bartonella and Theileria were significantly different among ticks of different species. Prevalence of Anaplasma and Theileria varied significantly among ticks of different counties. Anaplasma, Ehrlichia, Bartonella and Theileria were widely prevalent in ticks in Zhejiang Province suggesting other tick-borne pathogens should also be suspected if patients had history of tick bites.

Arthropods and associated pathogens from native and introduced rodents in Northeastern Italy.

Introduced Siberian chipmunks Eutamias sibiricus have been reported to be important reservoirs for human Lyme disease, as they may host high numbers of hard ticks carrying Borrelia spp. and other pathogens. In the present study, we assessed the prevalence of Borrelia spp. and other pathogenic bacteria in ectoparasite arthropod species infesting Siberian chipmunks and coexisting native small rodents. Small rodents were trapped with Sherman traps in Veneto (NE Italy), where the largest Italian populations of chipmunks occur. A total of 14 individual ticks were found on 223 rodents, with 6 more ticks obtained from stored dead chipmunks from the same study area. Ectoparasites were screened for pathogens by molecular analyses including species-specific PCR amplifications. Rickettsia monacensis, Borrelia lusitaniae, and Anaplasma platys were present in the parasites of both native rodents and introduced chipmunks. The present findings suggest a role for the invasive species E. sibiricus in the maintenance of the Ixodes ricinus life cycle, which may result in the modification of the transmission dynamics of tick-borne pathogens. Moreover, the presence of Rickettsia in urban populations of chipmunks may represent a serious risk for human health and should be investigated further.

Bacterial and protozoal pathogens found in ticks collected from humans in Corum province of Turkey.

BACKGROUND: Tick-borne diseases are increasing all over the word, including Turkey. The aim of this study was to determine the bacterial and protozoan vector-borne pathogens in ticks infesting humans in the Corum province of Turkey. METHODOLOGY/PRINCIPAL FINDINGS: From March to November 2014 a total of 322 ticks were collected from patients who attended the local hospitals with tick bites. Ticks were screened by real time-PCR and PCR, and obtained amplicons were sequenced. The dedected tick was belonging to the genus Hyalomma, Haemaphysalis, Rhipicephalus, Dermacentor and Ixodes. A total of 17 microorganism species were identified in ticks. The most prevalent Rickettsia spp. were: R. aeschlimannii (19.5%), R. slovaca (4.5%), R. raoultii (2.2%), R. hoogstraalii (1.9%), R. sibirica subsp. mongolitimonae (1.2%), R. monacensis (0.31%), and Rickettsia spp. (1.2%). In addition, the following pathogens were identified: Borrelia afzelii (0.31%), Anaplasma spp. (0.31%), Ehrlichia spp. (0.93%), Babesia microti (0.93%), Babesia ovis (0.31%), Babesia occultans (3.4%), Theileria spp. (1.6%), Hepatozoon felis (0.31%), Hepatozoon canis (0.31%), and Hemolivia mauritanica (2.1%). All samples were negative for Francisella tularensis, Coxiella burnetii, Bartonella spp., Toxoplasma gondii and Leishmania spp. CONCLUSIONS/SIGNIFICANCE: Ticks in Corum carry a large variety of human and zoonotic pathogens that were detected not only in known vectors, but showed a wider vector diversity. There is an increase in the prevalence of ticks infected with the spotted fever group and lymphangitis-associated rickettsiosis, while Ehrlichia spp. and Anaplasma spp. were reported for the first time from this region. B. microti was detected for the first time in Hyalomma marginatum infesting humans. The detection of B. occultans, B. ovis, Hepatozoon spp., Theileria spp. and Hemolivia mauritanica indicate the importance of these ticks as vectors of pathogens of veterinary importance, therefore patients with a tick infestation should be followed for a variety of pathogens with medical importance.

Chlamydiales, Anaplasma and Bartonella: persistence and immune escape of intracellular bacteria.

Intracellular bacteria, such as Chlamydiales, Anaplasma or Bartonella, need to persist inside their host in order to complete their developmental cycle and to infect new hosts. In order to escape from the host immune system, intracellular bacteria have developed diverse mechanisms of persistence, which can directly impact the health of their host.

Molecular evidence for trans-stadial transmission of Anaplasma platys by Rhipicephalus sanguineus sensu lato under field conditions.

This study investigated the transmission of Anaplasma platys by Rhipicephalus sanguineus sensu lato (Ixodida: Ixodidae). Engorged nymphs (n = 404) removed from A. platys-infected dogs were incubated at 28 °C until moulting. Unfed adults were obtained and divided into 48 pools. Unfed ticks collected from the grounds of the dog shelter, comprising 1800 larvae (n = 18 pools), 3100 nymphs (n = 62 pools) and 85 adults (n = 10 pools, including three male and seven female pools) were sorted into 90 pools. All pools were screened by polymerase chain reaction for the 16S rRNA gene of A. platys. Of 48 pools of unfed adults obtained from engorged nymphs, 12 were positive for A. platys; the infection rate maximum likelihood estimate (MLE) was 3.36 [95% confidence interval (CI) 1.84-5.68]. Anaplasma platys was detected in five of 23 male pools (MLE 2.82, 95% CI 1.06-6.20) and seven of 25 female pools (MLE 3.83, 95% CI 1.72-7.57). Of seven pools of unfed adult females collected from the shelter grounds, one was positive for A. platys (MLE 1.74, 95% CI 0.11-8.22). Among 62 unfed nymph pools, eight were infected with A. platys (MLE 0.27, 95% CI 0.13-0.52). No A. platys DNA was detected in the larva pools. The present results reveal molecular evidence for the trans-stadial transmission of A. platys by R. sanguineus s.l.

Occurrence of four Anaplasma species with veterinary and public health significance in sheep, northwestern China.

The members of the genus Anaplasma are important tick-borne rickettsial bacteria of veterinary and public health significance. Domestic ruminants are important reservoir hosts for several Anaplasma species. In this study, the occurrence of Anaplasma spp. was investigated by PCR in domestic small ruminants from Gansu, northwestern China. The results showed a high prevalence of Anaplasma spp. (46.2%, 201/435) in sheep. The average infection rates were 5.7%, 24.4%, 28.0% and 18.2% for A. ovis, A. bovis, A. phagocytophilum and A. capra, respectively. Coinfection of different Anaplasma species occurred in 96 (22.1%) sheep. The infections of Anaplasma species in sheep were confirmed by sequencing of msp4, 16S rRNA and gltA genes. Sequence analysis revealed a novel A. capra genotype in sheep that was distinct from the isolates identified from patients in northeastern China. This study gives the first insight of presence of four distinct Anaplasma species with veterinary and medical significance in sheep in northwestern China.

A novel zoonotic Anaplasma species is prevalent in small ruminants: potential public health implications.

BACKGROUND: Tick-borne diseases currently represent an important issue for global health. A number of emerging tick-transmitted microbes continue to be discovered, and some of these are already identified as the cause of human infections. Over the past two decades, Anaplasma phagocytophilum is considered to be mainly responsible for human anaplasmosis. However, a novel zoonotic pathogen provisionally named "Anaplasma capra" has recently been identified in China. In this study, we did an active surveillance of A. capra in goats and sheep in different geographical regions of China. METHODS: The presence of A. capra was determined by nested PCR in 547 blood samples collected from goats and sheep from 24 counties distributed in 12 provinces in China. The molecular characterization of A. capra isolates in sheep and goats was achieved based on four conventional genetic markers (16S rRNA, gltA, groEL and msp4 genes). RESULTS: Anaplasma capra was identified in 75 of 547 animals, with an overall prevalence of 13.7%. The infection rates in the survey sites ranged from 0 to 78.6%, and were significantly different (P < 0.01). Phylogenetic analysis revealed that the isolates obtained from goats, sheep, Ixodes persulcatus ticks and humans create a separate clade within the genus Anaplasma and distinct from other recognized Anaplasma species. These findings indicated that these A. capra isolates possess the same molecular characteristics, suggesting that this organism could be a substantial health threat to both animals and humans. CONCLUSIONS: Anaplasma capra is an emerging tick-transmitted zoonotic pathogen. This novel Anaplasna species is widespread across China with an overall prevalence of 13.7% in goats and sheep with isolates indistinguishable from those found in humans. These findings warrant increased public health awareness for human anaplasmosis.

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.

Evaluation of Gulf Coast Ticks (Acari: Ixodidae) for Ehrlichia and Anaplasma Species.

Amblyomma maculatum Koch (the Gulf Coast tick) is an aggressive, human-biting ixodid tick distributed throughout much of the southeastern United States and is the primary vector for Rickettsia parkeri, an emerging human pathogen. Amblyomma maculatum has diverse host preferences that include white-tailed deer, a known reservoir for Ehrlichia and Anaplasma species, including the human pathogens E. ewingii and E. chaffeensis. To examine more closely the potential role of A. maculatum in the maintenance of various pathogenic Ehrlichia and Anaplasma species, we screened DNA samples from 493 questing adult A. maculatum collected from six U.S. states using broad-range Anaplasmataceae and Ehrlichia genus-specific PCR assays. Of the samples tested, four (0.8%) were positive for DNA of Ehrlichia ewingii, one (0.2%) was positive for Anaplasma platys, and one (0.2%) was positive for a previously unreported Ehrlichia species closely related to Ehrlichia muris and an uncultivated Ehrlichia species from Haemaphysalis longicornis ticks in Japan. No ticks contained DNA of Ehrlichia chaffeensis, Ehrlichia canis, the Panola Mountain Ehrlichia, or Anaplasma phagocytophilum. This is the first identification of E. ewingii, A. platys, and the novel Ehrlichia in questing Gulf Coast ticks; nonetheless the low prevalence of these agents suggests that A. maculatum is not likely an important vector of these zoonotic pathogens.

Molecular and phylogenetic analysis of Anaplasma spp. in sheep and goats from six provinces of China.

Members of the genus Anaplasma are important emerging tick-borne pathogens in both humans and animals in tropical and subtropical areas. Here, we investigated the presence of Anaplasma spp. in 621 sheep and 710 goats from six provinces of China. Polymerase chain reaction (PCR) and DNA sequencing were conducted to determine the prevalence of Anaplasma (A.) phagocytophilum, A. ovis and A. bovis targeting the 16S ribosomal RNA or the major surface protein 4 gene. PCR revealed Anaplasma in 39.0% (240/621) of sheep and 45.5% (323/710) of goats. The most frequently detected species was A. ovis (88/621, 14.2% for sheep; 129/710, 18.2% for goats), followed by A. bovis (60/621, 9.7% for sheep; 74/710, 10.4% for goats) and A. phagocytophilum (33/621, 5.3% for sheep; 15/710, 2.1% for goats). Additionally, eight sheep and 20 goats were found to be infected with three pathogens simultaneously. DNA sequencing confirmed the presence of these three Anaplasma species in the investigated areas, and phylogenetic analysis indicated that there was geographic segregation to a certain extent, as well as a relationship between the host and cluster of A. ovis. The results of the present study provide valuable data that helps understand the epidemiology of anaplasmosis in ruminants from China.

Vertical transmission of Anaplasma platys and Leishmania infantum in dogs during the first half of gestation.

BACKGROUND: Leishmania infantum is a canine zoonotic vector-borne protozoan pathogen transmitted by phlebotomine sand flies, whereas Anaplasma platys is a bacterium most likely transmitted by ticks. While vertical transmission of L. infantum from pregnant bitches to their offspring has been documented, thus far no studies have explored the possibility of vertical transmission of A. platys in dogs. This study investigated the occurrence of vertical transmission of L. infantum and A. platys in sheltered dogs during the first half of gestation, in an area of southern Italy characterised by a high incidence of infection by both pathogens. METHODS: The study population included 20 bitches (n = 10 pregnant, at 25-35 days of pregnancy; n = 10 non-pregnant), all subjected to ovariohysterectomy, which were examined for the presence of L. infantum and A. platys via cytological screening of bone marrow and whole blood samples. Infection by L. infantum and A. platys was also tested by immunofluorescence antibody test (IFAT) and quantitative real-time PCR (qPCR) targeting both pathogens. Selected tissue samples (n = 210) collected during surgical procedures from bitches and foetuses (n = 20) were assessed for the presence of L. infantum and A. platys by qPCR targeting a fragment of the kinetoplast minicircle DNA (kDNA) and the 16S rRNA gene, respectively. RESULTS: Leishmania infantum DNA was not amplified from either uteri or ovaries from pregnant bitches or foetal tissue samples, whereas a subset of ovarian (n = 2) and uterine (n = 4) tissue samples from non-pregnant bitches were infected, with parasite loads of up to 3.09 × 10 and 7.51 parasite/PCR reaction, respectively. Conversely, uterine (n = 10) and ovarian (n = 8) tissues from both pregnant and non-pregnant bitches, together with a subset (n = 5) of foetal tissue samples were qPCR positive for A. platys. Leishmania infantum and A. platys nucleic acids were amplified from two uteri from non-pregnant bitches, with parasite loads of up to 2.32 × 10(-3) and 2.05 parasite/per PCR reaction, respectively. CONCLUSIONS: Results from this study suggest that, in contrast to L. infantum, A. platys can be transmitted from pregnant dogs to their offspring during the first half of gestation. This hypothesis remains to be verified, for instance via direct observation of parasites in postpartum foetal tissues.

Tick-borne pathogens of zoonotic and veterinary importance in Nigerian cattle.

BACKGROUND: Ticks and tick-borne diseases undermine cattle fitness and productivity in the whole of sub-Saharan Africa, including Nigeria. In this West African country, cattle are challenged by numerous tick species, especially during the wet season. Consequently, several TBDs are known to be endemic in Nigerian cattle, including anaplasmosis, babesiosis, cowdriosis and theilerioris (by Theileria mutans and Theileria velifera). To date, all investigations on cattle TBDs in Nigeria have been based on cytological examinations and/or on serological methods. This study aimed to ascertain the occurrence of tick-borne pathogens of veterinary and zoonotic importance in cattle in Nigeria using molecular approaches. METHODS: In October 2008, 704 whole blood samples were collected from indigenous cattle in the Plateau State, Nigeria. Analysis for tick-borne pathogens was conducted by means of PCR-based reverse line blotting (RLB) and sequencing targeting a panel of five genera of microorganisms (i.e. Babesia, Theileria, Anaplasma, Ehrlichia and Rickettsia spp.). RESULTS: In total, 561/704 (82.6%) animals were found infected, with 465 (69.6%) of them being infected by two or more microorganisms, with up to 77 possible combinations of pathogens detected. Theileria mutans was the most prevalent microorganism (66.3%), followed by Theileria velifera (52.4%), Theileria taurotragi (39.5%), Anaplasma marginale (39.1%), Anaplasma sp. (Omatjenne) (34.7%), Babesia bigemina (7.9%), Anaplasma centrale (6.3%), Anaplasma platys (3.9%), Rickettsia massiliae (3.5%), Babesia bovis (2.0%) and Ehrlichia ruminantium (1.1%). Calves were found significantly less infected than juvenile and adult cattle. CONCLUSIONS: This study provides updated, molecular-based information on cattle TBDs in Nigeria. The molecular approach employed allowed the diagnosis of numerous positive cases including carrier statuses, multiple infections and novel pathogen detections within the indigenous cattle population. Moreover, the RLB method here described enabled the detection of veterinary agents not only pertaining to bovine health, including also those of zoonotic importance. The high prevalence recorded for T. mutans, T. velifera, A. marginale, T. taurotragi and Anaplasma sp. (Omatjenne), suggests they may be endemically established in Nigeria, whereas the lower prevalence recorded for other microorganisms (i.e. A. centrale and B. bovis) highlights a less stable epidemiological scenario, requiring further investigations.

Alpha proteobacteria of genus Anaplasma (Rickettsiales: Anaplasmataceae): Epidemiology and characteristics of Anaplasma species related to veterinary and public health importance.

The Anaplasma species 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, Dermacentor and Amblyomma genera of ticks are the important vectors of Anaplasma. 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 among Anaplasma species. 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.