RESUMO
Ticks can transmit viruses, bacteria, and parasites to humans, livestock, and pet animals causing tick-borne diseases (TBDs) mechanically or biologically in the world. Lumpy skin disease virus, Anaplasma marginale, and Theileria annulata inflict severe infections in cattle, resulting in significant economic losses worldwide. The study investigated the potential transmissions of LSDV, A. marginale, and T. annulata through male Hyalomma anatolicum ticks in cattle calves. Two 6-month-old Holstein crossbred calves designated as A and B were used. On day 1, 15 uninfected female ticks (IIa) and infected batch of 40 male ticks (I) were attached on calf A for 11 days. Filial transmission of the infections was observed in female ticks (IIb) collected from calf A, where 8 female ticks had been co-fed with infected male ticks. The blood sample of calf B was found positive through PCR for the infections. The larvae and egg pools obtained from the infected ticks were also tested positive in PCR. The study confirmed the presence of these mixed pathogens and potential intra-stadial and transovarial transmissions of A. marginale, T. annulata, and LSDV in male and female ticks of H. anatolicum and experimental calves to establish the feasibility of infections through an in vivo approach.
Assuntos
Anaplasma marginale , Anaplasmose , Ixodidae , Vírus da Doença Nodular Cutânea , Theileria annulata , Theileriose , Animais , Bovinos , Masculino , Anaplasma marginale/isolamento & purificação , Ixodidae/virologia , Ixodidae/microbiologia , Theileria annulata/isolamento & purificação , Vírus da Doença Nodular Cutânea/fisiologia , Vírus da Doença Nodular Cutânea/isolamento & purificação , Feminino , Anaplasmose/transmissão , Theileriose/transmissão , Doença Nodular Cutânea/transmissão , Doença Nodular Cutânea/virologia , Doenças dos Bovinos/virologia , Doenças dos Bovinos/parasitologia , Doenças dos Bovinos/microbiologia , Doenças dos Bovinos/transmissão , Larva/virologiaRESUMO
Tick-borne bacteria of the genera Ehrlichia and Anaplasma cause several emerging human infectious diseases worldwide. In this study, we conduct an extensive survey for Ehrlichia and Anaplasma infections in the rainforests of the Amazon biome of French Guiana. Through molecular genetics and metagenomics reconstruction, we observe a high indigenous biodiversity of infections circulating among humans, wildlife, and ticks inhabiting these ecosystems. Molecular typing identifies these infections as highly endemic, with a majority of new strains and putative species specific to French Guiana. They are detected in unusual rainforest wild animals, suggesting they have distinctive sylvatic transmission cycles. They also present potential health hazards, as revealed by the detection of Candidatus Anaplasma sparouinense in human red blood cells and that of a new close relative of the human pathogen Ehrlichia ewingii, Candidatus Ehrlichia cajennense, in the tick species that most frequently bite humans in South America. The genome assembly of three new putative species obtained from human, sloth, and tick metagenomes further reveals the presence of major homologs of Ehrlichia and Anaplasma virulence factors. These observations converge to classify health hazards associated with Ehrlichia and Anaplasma infections in the Amazon biome as distinct from those in the Northern Hemisphere.
Assuntos
Anaplasma , Animais Selvagens , Ehrlichia , Filogenia , Floresta Úmida , Carrapatos , Anaplasma/genética , Anaplasma/isolamento & purificação , Anaplasma/patogenicidade , Anaplasma/classificação , Ehrlichia/genética , Ehrlichia/isolamento & purificação , Ehrlichia/classificação , Humanos , Animais , Carrapatos/microbiologia , Animais Selvagens/microbiologia , Anaplasmose/microbiologia , Anaplasmose/epidemiologia , Anaplasmose/transmissão , Guiana Francesa , Ehrlichiose/microbiologia , Ehrlichiose/epidemiologia , Ehrlichiose/veterinária , Ehrlichiose/transmissão , Metagenômica/métodos , Genoma Bacteriano/genética , RNA Ribossômico 16S/genéticaRESUMO
The genus Anaplasma includes A. marginale, A. centrale, A. bovis, A. ovis, A. platys, and A. phagocytophilum transmitted by ticks, some of which are zoonotic and cause anaplasmosis in humans and animals. In 2012, a new species was discovered in goats in China. In 2015, the same agent was detected in humans in China, and it was provisionally named Anaplasma capra, referring to 2012. The studies conducted to date have revealed the existence of A. capra in humans, domestic animals, wild animals, and ticks from three different continents (Asia, Europe, and Africa). Phylogenetic analyses based on gltA and groEL sequences show that A. capra clearly includes two different genotypes (A. capra genotype-1 and A. capra genotype-2). Although A. capra human isolates are in the genotype-2 group, goat, sheep, and cattle isolates are in both groups, making it difficult to establish a host genotype-relationship. According to current data, it can be thought that human isolates are genotype-2 and while only genotype-1 is found in Europe, both genotypes are found in Asia. Anaplasma capra causes clinical disease in humans, but the situation is not yet sufficient to understand the zoonotic importance and pathogenicity in animals. In the present review, the history, hosts (vertebrates and ticks), molecular prevalence, pathogenic properties, and genetic diversity of A. capra were evaluated from a broad perspective.
Assuntos
Anaplasma , Anaplasmose , Animais , Anaplasmose/microbiologia , Anaplasmose/epidemiologia , Anaplasmose/transmissão , Anaplasma/genética , Anaplasma/isolamento & purificação , Anaplasma/classificação , Anaplasma/patogenicidade , Humanos , Cabras , Zoonoses/microbiologia , Doenças Transmitidas por Carrapatos/microbiologia , Doenças Transmitidas por Carrapatos/epidemiologia , Doenças Transmitidas por Carrapatos/veterinária , Doenças Transmitidas por Carrapatos/transmissão , Filogenia , Doenças das Cabras/microbiologia , Doenças das Cabras/epidemiologia , Carrapatos/microbiologia , Doenças Transmissíveis Emergentes/microbiologia , Doenças Transmissíveis Emergentes/veterinária , Doenças Transmissíveis Emergentes/epidemiologiaRESUMO
This study assessed the duration of tick attachment necessary for a successful transmission of Anaplasma phagocytophilum by an infected I. scapularis nymph. Individual nymphs were placed upon BALB/c mice and allowed to feed for predetermined time intervals of 4 to 72 h. Ticks removed from mice at predetermined intervals were tested by PCR for verification of infection and evaluation of the bacterial load. The success of pathogen transmission to mice was assessed by blood-PCR at 7, 14 and 21 days postinfestation, and IFA at 21 days postinfestation. Anaplasma phagocytophilum infection was documented in 10-30 % of mice, from which ticks were removed within the first 20 h of feeding. However, transmission success was ≥70% if ticks remained attached for 36 h or longer. Notably, none of the PCR-positive mice that were exposed to infected ticks for 4 to 8 h and only half of PCR-positive mice exposed for 24 h developed antibodies within 3 weeks postinfestation. On the other hand, all mice with detectable bacteremia after being infested for 36 h seroconverted. This suggests that although some of the ticks removed prior to 24 h of attachment succeed in injecting a small amount of A. phagocytophilum, this amount is insufficient for stimulating humoral immunity and perhaps for establishing disseminated infection in BALB/c mice. Although A. phagocytophilum may be present in salivary glands of unfed I. scapularis nymphs, the amount of A. phagocytophilum initially contained in saliva appears insufficient to cause sustainable infection in a host. Replication and, maybe, reactivation of the agent for 12-24 h in a feeding tick is required before a mouse can be consistently infected.
Assuntos
Anaplasma phagocytophilum/fisiologia , Ehrlichiose/transmissão , Ixodes/fisiologia , Anaplasmose/microbiologia , Anaplasmose/transmissão , Animais , Ehrlichiose/microbiologia , Comportamento Alimentar , Feminino , Ixodes/crescimento & desenvolvimento , Camundongos , Camundongos Endogâmicos BALB C , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologiaRESUMO
Ehrlichioses and anaplasmosis have undergone dramatic increases in incidence, and the geographic ranges of their occurrence and vectors have also expanded. There is marked underreporting of these diseases owing to deficient physician awareness and knowledge of the illnesses as well as limited access to appropriate diagnostic tests. Human monocytic ehrlichiosis and anaplasmosis are life threatening diseases with estimated case fatality rates of 2.7 and 0.3%, respectively. However, knowledge of their full range of signs and symptoms is incomplete, and the incidence of subclinical infections is unknown. Currently available laboratory diagnostic methods are poorly utilized, and with the exception of nucleic acid amplification tests are not useful for diagnosis during the acute stage of illness when timely treatment is needed. The Ehrlichiosis and Anaplasmosis Subcommittee of the Tick-Borne Disease Working Group recommended active clinical surveillance to determine the true incidence, full clinical spectrum, and risk factors for severe illness, as well as standardized surveillance of ticks for these pathogens, and enhanced education of primary medical caregivers and the public regarding these diseases. The subcommittee identified the needs to develop sensitive, specific acute stage diagnostic tests for local clinical laboratories and point-of-care testing, to develop approaches for utilizing electronic medical records, data mining, and artificial intelligence for assisting early diagnosis and treatment, and to develop adjunctive therapies for severe disease.
Assuntos
Anaplasmose , Ehrlichiose , Monitoramento Epidemiológico , Vigilância da População , Anaplasmose/epidemiologia , Anaplasmose/microbiologia , Anaplasmose/transmissão , Ehrlichiose/epidemiologia , Ehrlichiose/microbiologia , Ehrlichiose/transmissão , Humanos , Incidência , Prevalência , Relatório de PesquisaRESUMO
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.
Assuntos
Anaplasma/fisiologia , Anaplasmose/microbiologia , Camelus/microbiologia , Dípteros/microbiologia , Camundongos/microbiologia , Coelhos/microbiologia , Doenças dos Roedores/microbiologia , Anaplasma/genética , Anaplasmose/transmissão , Animais , Camelus/parasitologia , Vetores de Doenças , Quênia , Doenças dos Roedores/transmissãoRESUMO
Vector-borne pathogens commonly establish multistrain infections, also called complex infections. How complex infections are established, either before or after the development of an adaptive immune response, termed coinfection or superinfection, respectively, has broad implications for the maintenance of genetic diversity, pathogen phenotype, epidemiology, and disease control strategies. Anaplasma marginale, a genetically diverse, obligate, intracellular, tick-borne bacterial pathogen of cattle, commonly establishes complex infections, particularly in regions with high transmission rates. Both coinfection and superinfection can be established experimentally; however, it is unknown how complex infections develop in a natural transmission setting. To address this question, we introduced naive animals into a herd in southern Ghana with a high infection prevalence and high transmission pressure and tracked the strain acquisition of A. marginale through time using multilocus sequence typing. As expected, the genetic diversity among strains was high, and 97% of animals in the herd harbored multiple strains. All the introduced naive animals became infected, and three to four strains were typically detected in an individual animal prior to seroconversion, while one to two new strains were detected in an individual animal following seroconversion. On average, the number of strains acquired via superinfection was 16% lower than the number acquired via coinfection. Thus, while complex infections develop via both coinfection and superinfection, coinfection predominates in this setting. These findings have broad implications for the development of control strategies in high-transmission settings.
Assuntos
Anaplasma marginale/genética , Anaplasmose/microbiologia , Coinfecção/microbiologia , Superinfecção/microbiologia , Alelos , Anaplasmose/etiologia , Anaplasmose/transmissão , Animais , Bovinos , Coinfecção/etiologia , Superinfecção/etiologiaRESUMO
Tick-borne illnesses pose a serious concern to human and veterinary health and their prevalence is on the rise. The interactions between ticks and the pathogens they carry are largely undefined. However, the genus Anaplasma, a group of tick-borne bacteria, has been instrumental in uncovering novel paradigms in tick biology. The emergence of sophisticated technologies and the convergence of entomology with microbiology, immunology, metabolism and systems biology has brought tick-Anaplasma interactions to the forefront of vector biology with broader implications for the infectious disease community. Here, we discuss the use of Anaplasma as an instrument for the elucidation of novel principles in arthropod-microbe interactions. We offer an outlook of the primary areas of study, outstanding questions and future research directions.
Assuntos
Anaplasma , Anaplasmose , Vetores Artrópodes/microbiologia , Interações Hospedeiro-Patógeno , Ixodes/microbiologia , Anaplasmose/microbiologia , Anaplasmose/transmissão , Animais , Biologia Computacional , Humanos , CamundongosRESUMO
The Asian longhorned tick, Haemaphysalis longicornis Neumann (Acari: Ixodidae), was recently introduced into the United States and is now established in at least 15 states. Considering its ability for parthenogenetic propagation and propensity for creating high-density populations, there is concern that this tick may become involved in transmission cycles of endemic tick-borne human pathogens. Human granulocytic anaplasmosis (HGA) caused by Anaplasma phagocytophilum is one of the more common tick-borne diseases in the United States, especially in the northeastern and midwestern states. There is considerable geographical overlap between HGA cases and the currently known distribution of H. longicornis, which creates a potential for this tick to encounter A. phagocytophilum while feeding on naturally infected vertebrate hosts. Therefore, we evaluated the ability of H. longicornis to acquire and transmit the agent of HGA under laboratory conditions and compared it to the vector competence of I. scapularis. Haemaphysalis longicornis nymphs acquired the pathogen with the bloodmeal while feeding on infected domestic goats, but transstadial transmission was inefficient and PCR-positive adult ticks were unable to transmit the pathogen to naïve goats. Results of this study indicate that the Asian longhorned tick is not likely to play a significant role in the epidemiology of HGA in the United States.
Assuntos
Anaplasma phagocytophilum/fisiologia , Anaplasmose/transmissão , Vetores Aracnídeos/microbiologia , Ehrlichiose/transmissão , Ixodidae/microbiologia , Animais , Feminino , Cabras , Ixodidae/crescimento & desenvolvimento , Masculino , Ninfa/crescimento & desenvolvimento , Ninfa/microbiologia , Estados UnidosRESUMO
BACKGROUND: Tick-borne diseases (TBDs) constitute a major constraint for livestock development in sub-Saharan Africa, with East Coast fever (ECF) being the most devastating TBD of cattle. However, in Burundi, detailed information is lacking on the current prevalence of TBDs and on the associated economic losses from mortality and morbidity in cattle as well as the costs associated with TBD control and treatment. The aim of this study was, therefore, to assess the prevalence and spatial distribution of tick-borne pathogens (TBPs) in cattle across the major agro-ecological zones (AEZs) in Burundi. METHODS: In a cross-sectional study conducted in ten communes spanning the five main AEZs in Burundi, blood samples were taken from 828 cattle from 305 farms between October and December 2017. Evidence of Theileria parva infection was assessed by antibody level, measured using a polymorphic immunodominant molecule (PIM) antigen-based enzyme-linked immunosorbent assay (ELISA) and by a T. parva-specific p104 gene-based nested PCR. Antibodies against Theileria mutans infection were detected using the 32-kDa antigen-based indirect ELISA, while the 200-kDa antigen and the major surface protein 5 (MSP5)-based indirect ELISA were used to detect antibodies against Babesia bigemina and Anaplasma marginale, respectively. RESULTS: The prevalence of T. parva across the ten communes sampled ranged from 77.5 to 93.1% and from 67.8 to 90.0% based on the ELISA and PCR analysis, respectively. A statistically significant difference in infection was observed between calves and adult cattle; however, T. parva infection levels were not significantly associated with sex and breed. The seroprevalence indicating exposure to T. mutans, B. bigemina and A. marginale ranged from 30 to 92.1%, 33.7 to 90% and 50 to 96.2%, respectively. Mixed infections of TBPs were detected in 82.91% of cattle sampled, with 11 different combinations of pathogen species detected . CONCLUSIONS: The findings indicate that T. parva, A. marginale and B. bigemina infections are endemic in Burundi. Knowledge of the spatial distribution of TBPs will facilitate the design of effective targeted strategies to control these diseases. There is a need for further investigations of the distribution of tick vectors and the population structure of TBPs in order to identify the key epidemiological factors contributing to TBD outbreaks in Burundi.
Assuntos
Anaplasmose/epidemiologia , Babesiose/epidemiologia , Doenças dos Bovinos/epidemiologia , Theileriose/epidemiologia , Doenças Transmitidas por Carrapatos/epidemiologia , Carrapatos/parasitologia , Anaplasma marginale/imunologia , Anaplasmose/transmissão , Distribuição Animal , Animais , Anticorpos Antiprotozoários/sangue , Babesia/imunologia , Babesiose/transmissão , Burundi/epidemiologia , Bovinos , Doenças dos Bovinos/parasitologia , Doenças dos Bovinos/transmissão , Estudos Transversais , Doenças Endêmicas , Feminino , Masculino , Prevalência , Estudos Soroepidemiológicos , Theileria parva/imunologia , Theileriose/imunologia , Theileriose/transmissão , Doenças Transmitidas por Carrapatos/transmissãoRESUMO
BACKGROUND: The density of Ixodes ricinus nymphs infected with Anaplasma phagocytophilum is one of the parameters that determines the risk for humans and domesticated animals to contract anaplasmosis. For this, I. ricinus larvae need to take a bloodmeal from free-ranging ungulates, which are competent hosts for A. phagocytophilum. METHODS: Here, we compared the contribution of four free-ranging ungulate species, red deer (Cervus elaphus), fallow deer (Dama dama), roe deer (Capreolus capreolus), and wild boar (Sus scrofa), to A. phagocytophilum infections in nymphs. We used a combination of camera and live trapping to quantify the relative availability of vertebrate hosts to questing ticks in 19 Dutch forest sites. Additionally, we collected questing I. ricinus nymphs and tested these for the presence of A. phagocytophilum. Furthermore, we explored two potential mechanisms that could explain differences between species: (i) differences in larval burden, which we based on data from published studies, and (ii) differences in associations with other, non-competent hosts. RESULTS: Principal component analysis indicated that the density of A. phagocytophilum-infected nymphs (DIN) was higher in forest sites with high availability of red and fallow deer, and to a lesser degree roe deer. Initial results suggest that these differences are not a result of differences in larval burden, but rather differences in associations with other species or other ecological factors. CONCLUSIONS: These results indicate that the risk for contracting anaplasmosis in The Netherlands is likely highest in the few areas where red and fallow deer are present. Future studies are needed to explore the mechanisms behind this association.
Assuntos
Anaplasma phagocytophilum/fisiologia , Cervos/parasitologia , Ixodes/microbiologia , Ninfa/microbiologia , Ninfa/fisiologia , Infestações por Carrapato/veterinária , Anaplasmose/epidemiologia , Anaplasmose/transmissão , Distribuição Animal , Animais , Animais Selvagens/parasitologia , Estudos Transversais , Cervos/classificação , Florestas , Humanos , Ixodes/fisiologia , Países BaixosRESUMO
The objective of this study was to investigate evidence of emerging anaplasmosis and bartonellosis in rodents from endemic areas of Nakhon Ratchasima, Thailand. Rodent trapping was undertaken in 13 sub-districts of Muang District. The live-capture traps were set up in three locations of selected scrub typhus patient houses for three consecutive nights. Wild-caught rodent whole blood samples and associated ticks and fleas were collected and tested for Anaplasma spp. and Bartonella spp. In addition, heat maps using GIS software were used to determine the density of infection of positive wild-caught rodents. A total of 347 wild-caught rodents of nine species was captured. Rattus rattus (38.6%) was the dominant species. A total of 1,518 Heamaphysalis bandicota ticks and 57 Xenopsylla cheopis fleas was removed. Twenty-two of the 347 tested blood samples (6.3%) were Anaplasma bovis-positive and 121 blood samples and five out of 27 pools of X. cheopis fleas were Bartonella queenslandensis-positive. Of these infected rodents, dual-infections between A. bovis and B. queenslandensis were found in three B. indica rodents. Our results offer new information concerning the infections of A. bovis and B. queenslandensis in both rodents and their ectoparasites collected in high-risk areas of rodent-borne diseases in Thailand.
Assuntos
Anaplasma/isolamento & purificação , Bartonella/isolamento & purificação , Ixodidae/microbiologia , Murinae/parasitologia , Xenopsylla/microbiologia , Anaplasmose/transmissão , Animais , Infecções por Bartonella/transmissão , Insetos Vetores/microbiologiaRESUMO
Ticks are important vectors that transmit several pathogens including human anaplasmosis agent, Anaplasma phagocytophilum. This bacterium is an obligate intracellular rickettsial pathogen. An infected reservoir animal host is often required for maintenance of this bacterial colony and as a source for blood to perform needle inoculations in naïve animals for tick feeding studies. In this study, we report an efficient microinjection method to generate A. phagocytophilum-infected ticks in laboratory conditions. The dense-core (DC) form of A. phagocytophilum was isolated from in vitro cultures and injected into the anal pore of unfed uninfected Ixodes scapularis nymphal ticks. These ticks successfully transmitted A. phagocytophilum to the murine host. The bacterial loads were detected in murine blood, spleen, and liver tissues. In addition, larval ticks successfully acquired A. phagocytophilum from mice that were previously infected by feeding with DC-microinjected nymphal ticks. Transstadial transmission of A. phagocytophilum from larvae to nymphal stage was also evident in these ticks. Taken together, our study provides a timely, rapid, and an efficient method not only to generate A. phagocytophilum-infected ticks but also provides a tool to understand acquisition and transmission dynamics of this bacterium and perhaps other rickettsial pathogens from medically important vectors.
Assuntos
Anaplasma phagocytophilum/fisiologia , Anaplasmose/transmissão , Ixodes/microbiologia , Técnicas Microbiológicas/métodos , Microinjeções/métodos , Animais , Vetores Aracnídeos/microbiologia , Carga Bacteriana , Sangue/microbiologia , Feminino , Células HL-60 , Humanos , Ixodes/crescimento & desenvolvimento , Fígado/microbiologia , Camundongos , Ninfa/microbiologia , Baço/microbiologiaRESUMO
As one of the important tick-borne zoonotic pathogens, Anaplasma has both veterinary and public health significance. Here, we performed a survey of Anaplasma infection in the goats from a farm in Beijing, China, and found 44.6% (41/92) were infected with Anaplasma capra, and 22.8% (21/92) were infected with Anaplasma sp. This Anaplasma sp. bacterium was close to a recently emerging Anaplasma platys strain based on gltA and groEL gene phylogenetic analysis. As to further understand the characteristics of Anaplasma sp., we raised a couple of positive goats (n = 2) in the laboratory with tick-free settings. We observed inappetence, vomiting, high fever, and weakness of limbs in the goat's offspring (n = 3). In addition, the blood samples from all offspring were all positive of this Anaplasma spp. We did not see any intracellular morulae in neutrophils, monocytes, and erythrocytes, but we identified some in the platelets of the blood smears from the positive goats by light microscopy. We named it A. platys-like and suggested it may infect platelets and be transmitted vertically through the placenta of goats. These findings deserve further evaluation.
Assuntos
Anaplasma/classificação , Anaplasma/isolamento & purificação , Anaplasmose/epidemiologia , Anaplasma/genética , Anaplasma/patogenicidade , Anaplasmose/transmissão , Animais , Pequim/epidemiologia , Plaquetas/microbiologia , Feminino , Doenças das Cabras/microbiologia , Doenças das Cabras/transmissão , Cabras , Transmissão Vertical de Doenças Infecciosas/veterinária , Masculino , FilogeniaRESUMO
Climate change ranks among the most important issues globally, affecting geographic distributions of vectors and pathogens, and inducing losses in livestock production among many other damaging effects. We characterized the potential geographic distribution of the ticks Rhipicephalus (Boophilus) microplus, an important vector of babesiosis and anaplasmosis globally. We evaluated potential geographic shifts in suitability patterns for this species in two periods (2050 and 2070) and under two emissions scenarios (RCPs 4.5 and 8.5). Our results anticipate increases in suitability worldwide, particularly in the highest production areas for cattle. The Indo-Malayan region resulted in the highest cattle exposure under both climate change projections (2050), with increases in suitability of > 30%. This study illustrates how ecological niche modeling can be used to explore probable effects of climate change on disease vectors, and the possible consequences on economic dimensions.
Assuntos
Distribuição Animal , Vetores Aracnídeos/fisiologia , Mudança Climática , Rhipicephalus/fisiologia , Anaplasmose/transmissão , Animais , Vetores Aracnídeos/microbiologia , Vetores Aracnídeos/parasitologia , Babesiose/transmissão , Ecossistema , Modelos Biológicos , Rhipicephalus/microbiologia , Rhipicephalus/parasitologiaRESUMO
BACKGROUND: Domestic dogs (Canis familiaris) have the potential to act as disease reservoirs for wildlife and are important sentinels for common circulating pathogens. Therefore, the infectious disease seroprevalence among domestic dogs in northern Botswana may be indicative of pathogen exposure of various wildlife species. The objective of this study was to assess the seroprevalence of Ehrlichia spp., Borrelia burgdorferi, Anaplasma spp., Dirofilaria immitis, canine adenovirus, canine parvovirus, and canine distemper virus in domestic dogs as proxies of disease prevalence in the local wildlife in the Okavango Delta region of Botswana. Statistical analysis assessed crude and factor-specific seroprevalence proportions in relation to age, sex, and geographical location as predictors of seropositivity. Logistic regression was used to identify adjusted predictors of seropositivity for each of the pathogens of interest. RESULTS: Samples from 233 dogs in a total of seven locations in Maun, Botswana, and surrounding villages were collected and serologically analyzed. No dogs were seropositive for B. burgdorferi, while low seroprevalence proportions were observed for Anaplasma spp. (2.2%) and D. immitis (0.9%). Higher seroprevalence proportions were observed for the tick-borne pathogen Ehrlichia spp. (21.0%), and 19.7% were seropositive for canine adenovirus (hepatitis). The highest seroprevalence proportions were for canine parvovirus (70.0%) and canine distemper virus (44.8%). The predictors of seropositivity revealed that adults were more likely to be seropositive for canine adenovirus, canine distemper virus, and canine parvovirus than juveniles, and location was a risk factor for canine adenovirus, canine distemper virus, canine parvovirus, and Ehrlichia spp. CONCLUSIONS: Results indicate that increasing tick control and vaccination campaigns for domestic dogs may improve the health of domestic animals, and potentially wildlife and humans in the Okavango Delta since viral and vector-borne bacterial pathogens can be transmitted between them.
Assuntos
Anaplasmose/epidemiologia , Dirofilariose/epidemiologia , Cinomose/epidemiologia , Doenças do Cão/epidemiologia , Ehrlichiose/veterinária , Doença de Lyme/veterinária , Infecções por Parvoviridae/veterinária , Anaplasma/isolamento & purificação , Anaplasma/patogenicidade , Anaplasmose/microbiologia , Anaplasmose/transmissão , Animais , Anticorpos Antibacterianos/sangue , Anticorpos Anti-Helmínticos/sangue , Anticorpos Antivirais/sangue , Vetores Aracnídeos/microbiologia , Borrelia burgdorferi/isolamento & purificação , Borrelia burgdorferi/patogenicidade , Botsuana/epidemiologia , Dirofilaria immitis/isolamento & purificação , Dirofilaria immitis/patogenicidade , Dirofilariose/microbiologia , Dirofilariose/transmissão , Cinomose/microbiologia , Cinomose/transmissão , Vírus da Cinomose Canina/isolamento & purificação , Vírus da Cinomose Canina/patogenicidade , Doenças do Cão/microbiologia , Doenças do Cão/transmissão , Cães , Ehrlichia/isolamento & purificação , Ehrlichia/patogenicidade , Ehrlichiose/epidemiologia , Ehrlichiose/microbiologia , Ehrlichiose/transmissão , Feminino , Humanos , Doença de Lyme/epidemiologia , Doença de Lyme/microbiologia , Doença de Lyme/transmissão , Masculino , Infecções por Parvoviridae/epidemiologia , Infecções por Parvoviridae/microbiologia , Infecções por Parvoviridae/transmissão , Parvovirus Canino/isolamento & purificação , Parvovirus Canino/patogenicidade , Animais de Estimação/microbiologia , Animais de Estimação/parasitologia , Animais de Estimação/virologia , Estudos Soroepidemiológicos , Carrapatos/microbiologiaRESUMO
Anaplasma capra is an emerging zoonotic tick-borne pathogen with a broad host range, including many mammals. Dogs have close physical interactions with humans and regular contact with the external environment. Moreover, they have been previously reported to be hosts of Anaplasma phagocytophilum, A. platys, A. ovis, and A. bovis. To confirm whether dogs are also hosts of A. capra, pathogen DNA was extracted from blood samples of 521 dogs, followed by PCR amplification of the citrate synthase (gltA) gene, heat shock protein (groEL) gene, and major surface protein 4 (msp4) gene of the A. capra. A total of 12.1% (63/521) of blood samples were shown to be A. capra-positive by PCR screening. No significant differences were observed between genders (P = 0.578) or types (P = 0.154) of dogs with A. capra infections. However, significantly higher A. capra infections occurred in dogs with regular contact with vegetation (P = 0.002), those aged over 10 years (P = 0.040), and during the summer season (P = 0.006). Phylogenetic analysis based on gltA, groEL, and msp4 sequences demonstrated that the isolates obtained in this study were clustered within the A. capra clade, and were distinct from other Anaplasma species. In conclusion, dogs were shown to be a host of the human pathogenic A. capra. Considering the affinity between dogs and humans and the zoonotic tick-borne nature of A. capra, dogs should be carefully monitored for the presence of A. capra.
Assuntos
Anaplasma/classificação , Anaplasmose/epidemiologia , Anaplasmose/microbiologia , Doenças Transmissíveis Emergentes/epidemiologia , Doenças do Cão/epidemiologia , Doenças do Cão/microbiologia , Anaplasma/genética , Anaplasmose/transmissão , Animais , China/epidemiologia , Doenças do Cão/transmissão , Cães , Filogenia , Análise de Sequência de DNA , Doenças Transmitidas por Carrapatos , ZoonosesRESUMO
Anaplasma phagocytophilum is the agent of tick-borne fever, equine, canine and human granulocytic anaplasmosis. The common route of A. phagocytophilum transmission is through a tick bite, the main vector in Europe being Ixodes ricinus. Despite the apparently ubiquitous presence of the pathogen A. phagocytophilum in ticks and various wild and domestic animals from Europe, up to date published clinical cases of human granulocytic anaplasmosis (HGA) remain rare compared to the worldwide status. It is unclear if this reflects the epidemiological dynamics of the human infection in Europe or if the disease is underdiagnosed or underreported. Epidemiologic studies in Europe have suggested an increased occupational risk of infection for forestry workers, hunters, veterinarians, and farmers with a tick-bite history and living in endemic areas. Although the overall genetic diversity of A. phagocytophilum in Europe is higher than in the USA, the strains responsible for the human infections are related on both continents. However, the study of the genetic variability and assessment of the difference of pathogenicity and infectivity between strains to various hosts has been insufficiently explored to date. Most of the European HGA cases presented as a mild infection, common clinical signs being pyrexia, headache, myalgia and arthralgia. The diagnosis of HGA in the USA was recommended to be based on clinical signs and the patient's history and later confirmed using specialized laboratory tests. However, in Europe since the majority of cases are presenting as mild infection, laboratory tests may be performed before the treatment in order to avoid antibiotic overuse. The drug of choice for HGA is doxycycline and because of potential for serious complication the treatment should be instituted on clinical suspicion alone.
Assuntos
Anaplasma phagocytophilum/efeitos dos fármacos , Anaplasmose/tratamento farmacológico , Antibacterianos/administração & dosagem , Anaplasma phagocytophilum/classificação , Anaplasma phagocytophilum/genética , Anaplasma phagocytophilum/isolamento & purificação , Anaplasmose/epidemiologia , Anaplasmose/microbiologia , Anaplasmose/transmissão , Animais , Europa (Continente)/epidemiologia , Cavalos , Humanos , Ixodes/parasitologia , Ixodes/fisiologiaRESUMO
Aerobic organisms evolved conserved mechanisms controlling the generation of reactive oxygen species (ROS) to maintain redox homeostasis signaling and modulate signal transduction, gene expression and cellular functional responses under physiological conditions. The production of ROS by mitochondria is essential in the oxidative stress associated with different pathologies and in response to pathogen infection. Anaplasma phagocytophilum is an intracellular pathogen transmitted by Ixodes scapularis ticks and causing human granulocytic anaplasmosis. Bacteria multiply in vertebrate neutrophils and infect first tick midgut cells and subsequently hemocytes and salivary glands from where transmission occurs. Previous results demonstrated that A. phagocytophilum does not induce the production of ROS as part of its survival strategy in human neutrophils. However, little is known about the role of ROS during pathogen infection in ticks. In this study, the role of tick oxidative stress during A. phagocytophilum infection was characterized through the function of different pathways involved in ROS production. The results showed that tick cells increase mitochondrial ROS production to limit A. phagocytophilum infection, while pathogen inhibits alternative ROS production pathways and apoptosis to preserve cell fitness and facilitate infection. The inhibition of NADPH oxidase-mediated ROS production by pathogen infection appears to occur in both neutrophils and tick cells, thus supporting that A. phagocytophilum uses common mechanisms for infection of ticks and vertebrate hosts. However, differences in ROS response to A. phagocytophilum infection between human and tick cells may reflect host-specific cell tropism that evolved during pathogen life cycle.
Assuntos
Anaplasma phagocytophilum/patogenicidade , Anaplasmose/microbiologia , Vetores de Doenças , Interações Hospedeiro-Patógeno , Ixodes/microbiologia , Redes e Vias Metabólicas , Neutrófilos/microbiologia , Anaplasma phagocytophilum/metabolismo , Anaplasmose/metabolismo , Anaplasmose/transmissão , Animais , Regulação da Expressão Gênica , Células HL-60 , Humanos , Neutrófilos/metabolismo , Oxirredução , Estresse Oxidativo , Coelhos , Ovinos , Transdução de SinaisRESUMO
BACKGROUND: Four species within Anaplasma genus are emerging zoonotic pathogens, which are transmitted by ticks and generate veterinary and public health concerns. Here, we performed a molecular survey of Anaplasma in Ankang, Northwest China. METHODS: Hard ticks were collected and identified using morphological and molecular methods. Human-pathogenic Anaplasma species were tested using nested polymerase chain reaction. The nearly complete rrs, gltA, and groEL genes sequences from revealed Anaplasma species were amplified and sequenced to determine their molecular characteristics and their phylogeny. RESULTS: All ticks collected in Ankang belonged to the Rhipicephalus microplus. Novel unclassified Anaplasma strains genetically related to A. platys and A. capra were detected in these ticks. Co-infection of these two organisms was also found. The novel unclassified Anaplasma strains identified in this study formed a distinct phylogenetic lineage based on the groEL gene and two lineages based on the gltA gene within A. platys and related strains group. The revealed A. capra strains identified in this study were most closely related to those detected in humans and other vertebrate animals. CONCLUSION: We revealed the presence of A. capra, a novel human pathogens in R. microplus ticks in previously unrecognized endemic regions. We also detected a novel unclassified Anaplasma species genetically related to A. platys. The epidemiology of anaplasmosis caused by these two Anaplasma species in humans should be assessed in future studies.