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1.
Anaplasma phagocytophilum, the causative agent of human granulocytotropic anaplasmosis, can infect white-tailed deer (WTD; Odocoileus virginianus), and this species is a crucial host for adult Ixodes scapularis, the primary vector of A. phagocytophilum. The goal of this study was to determine the geographic distribution of A. phagocytophilum among WTD across a 19 state region and to evaluate the utility of WTD as natural sentinels. Serologic testing using the indirect fluorescent antibody (IFA) assay was conducted on WTD serum samples and molecular and xenodiagnostic tests were performed to confirm serologic results. The surveillance system was assessed through examination of vital attributes including WTD age and gender associations with serologic status, sample size adequacy for accurate infection status classification, and presence of the vector, I. scapularis. Six hundred thirty-three of 2,666 (24%) WTD in 17 states tested positive for antibodies (>or=128) when tested by IFA assay. Testing for p44 and/or 16S rRNA gene targets identified 73 (16%) PCR positive WTD among 458 animals tested, all of which originated from seropositive populations. Attempts to culture A. phagocytophilum from WTD were unsuccessful; however, xenodiagnostic mice inoculated with blood from 3 WTD became infected. Seroprevalence did not differ by deer age or gender; however, WTD相似文献   

2.
In the northeastern United States, Anaplasma phagocytophilum, the agent of human granulocytic ehrlichiosis (HGE), is transmitted by the tick vector Ixodes scapularis. The white-footed mouse Peromyscus leucopus is a competent reservoir for this agent, but the reservoir competence of non-Peromyscus hosts of I. scapularis has not been studied. Here, we report data confirming reservoir competence of medium-sized mammals for A. phagocytophilum. Raccoons, Virginia opossums, gray squirrels, and striped skunks were live-trapped in June-August of 1998-1999 at two locations in Connecticut. Captured animals were kept for several days at the laboratory in wire-mesh cages over water to allow naturally attached ticks to drop off. Samples of blood and serum were taken from each animal prior to its release at the site of capture. Engorged ticks collected from each animal were allowed to molt. Resulting I. scapularis nymphs and adults were tested for the presence of A. phagocytophilum DNA by polymerase chain reaction, as were the blood samples from the animals. A. phagocytophilum DNA was detected in the blood of >10% of the raccoons tested. Raccoons, opossums, squirrels, and skunks produced adult I. scapularis infected with the agent of HGE. Prevalence of infection was the highest in adult ticks fed as nymphs upon raccoons (23%) and the lowest in those fed upon skunks and opossums (5-7%). The agent was present in nymphal I. scapularis fed as larvae upon raccoons and squirrels, but not in ticks fed upon skunks or opossums. We also tested the ability of I. scapularis to transmit A. phagocytophilum to laboratory-reared white-footed mice after acquiring it from medium-sized mammals. Ticks that acquired the agent from raccoons and squirrels successfully transmitted it to mice. Thus, raccoons and gray squirrels are reservoir-competent for the agent of HGE-they become naturally infected, and are capable of transmitting the infection to feeding ticks.  相似文献   

3.
This study is part of a project that aimed to better understand the role of small mammals in the maintenance of the tick-borne encephalitis virus at four different sites in Switzerland. Here we focused on the detection of three intracellular pathogens, Anaplasma phagocytophilum, Rickettsia spp., and Babesia spp., in field-derived ticks that detached from 79 small mammals. We analyzed 465 Ixodes ricinus larvae after their molt and 14 semiengorged I. trianguliceps that were feeding on rodents. No pathogen was detected in I. trianguliceps. In I. ricinus, the most frequently detected pathogen was Rickettsia spp. (7.3%). All Rickettsia spp. identified DNA belonged to R. helvetica except one DNA sample that was identified as R. monacensis. The prevalence of Babesia spp. reached 2.4% and identification at the species level revealed B. venatorum (1.7%) and B. microti (0.4%). A. phagocytophilum was not detected in I. ricinus that detached from rodents. To verify the absence of A. phagocytophilum at the four sites, additional questing nymphs collected at these sites were analyzed for A. phagocytophilum. This pathogen was detected at one site only, where 2% (2/100) of questing ticks were infected. Some of these emerging pathogens are described for the first time in molted larvae that fed on rodents. The presence of medically relevant pathogens, with a global prevalence of 9.9%, highlights the importance to inform the medical corporation on the risk for human health in these areas.  相似文献   

4.
Carlyon JA  Akkoyunlu M  Xia L  Yago T  Wang T  Cummings RD  McEver RP  Fikrig E 《Blood》2003,102(9):3387-3395
Anaplasma phagocytophilum causes human granulocytic ehrlichiosis, the second most common tick-borne disease in the United States. Mice are natural reservoirs for this bacterium and man is an inadvertent host. A phagocytophilum's tropism for human neutrophils is linked to neutrophil expression of P-selectin glycoprotein ligand-1 (PSGL-1), as well as sialylated and alpha1,3-fucosylated glycans. To determine whether A phagocytophilum uses similar molecular features to infect murine neutrophils, we assessed in vitro bacterial binding to neutrophils from and infection burden in wild-type mice; mice lacking alpha 1,3-fucosyltransferases Fuc-TIV and Fuc-TVII; or mice lacking PSGL-1. Binding to Fuc-TIV-/-/Fuc-TVII-/- neutrophils and infection of Fuc-TIV-/-/Fuc-TVII-/- mice were significantly reduced relative to wild-type mice. A phagocytophilum binding to PSGL-1-/- neutrophils was modestly reduced, whereas sialidase treatment significantly decreased binding to both wild-type and PSGL-1-/- neutrophils. A phagocytophilum similarly infected PSGL-1-/- and wild-type mice in vivo. A phagocytophilum induced comparable levels of chemokines from wild-type and PSGL-1-/- neutrophils in vitro, while those induced from Fuc-TIV-/-/Fuc-TVII-/- neutrophils were appreciably reduced. Therefore, A phagocytophilum infection in mice, as in humans, requires sialylation and alpha1,3-fucosylation of neutrophils. However, murine infection does not require neutrophil PSGL-1 expression, which has important implications for understanding how A phagocytophilum binds and infects neutrophils.  相似文献   

5.
Anaplasma phagocytophilum is an emerging tick-borne pathogen with both veterinary and human health implications. The role of wildlife hosts for this pathogen are not well defined, even thought roe deer (Capreolus capreolus) has been suggested to contribute to the occurrence of this tick-borne diseases in Europe. Therefore the aim of the present study was to investigate the potential role of this ungulate species as a reservoir of human pathogenic strains of A. phagocytophilum in a tick-borne diseases endemic area in Northeastern Italy. Ixodes ricinus feeding on roe deer were collected and analyzed for the presence for A. phagocytophilum by a molecular approach targeting 16S rRNA and groEL genes. The mean prevalence of A. phagocytophilum recorded was 5.11%, highlighting the ability of roe deer to infect the I. ricinus larval stage. The results of further genetic characterization of the strains of A. phagocytophilum herein isolated, based on phylogenetic information contained in groEL gene sequences, showed substantial heterogeneity among sequences analyzed. Nevertheless, these findings suggest that the roe deer population of the Trentino region of Italy harbors strains of A. phagocytophilum of unknown pathogenicity for humans.  相似文献   

6.
7.
目的 了解北京东北部山区人群嗜吞噬细胞无形体的感染状况,为制定相应的防控策略提供依据。方法 在北京密云与怀柔区采集人群血清,采用间接免疫荧光法检测嗜吞噬细胞无形体IgG抗体,进行血清流行病学调查。结果 801份血清中嗜吞噬细胞无形体IgG抗体阳性者106份,阳性率13.23%,其中密云区为13.48%,怀柔区为12.70%,差异无统计学意义(P>0.05)。结论 北京密云与怀柔区正常人群中均有嗜吞噬细胞无形体感染的存在,应加强人粒细胞无形体病的监测和防控工作。  相似文献   

8.
The natural history of Ehrlichia chaffeensis, the causative agent of human monocytotropic ehrlichiosis, includes the lone star tick (LST, Amblyomma americanum) as a vector and white-tailed deer (WTD; Odocoileus virginianus) as both a natural reservoir of E. chaffeensis and a major host of LST. The goal of the current study was to implement and evaluate a prototype surveillance system to delineate the geographic distribution of E. chaffeensis using WTD as natural sentinels. To accomplish this goal, serologic testing using the indirect immunofluorescent antibody (IFA) test was performed on WTD serum samples, and to confirm serologic results, polymerase chain reaction (PCR) assays and culture isolation were conducted. Considerations relevant to the applicability of a surveillance system utilizing WTD were analyzed (e.g., age and gender relationships to serologic status, adequacy of sample sizes needed to distinguish between uninfected and infected populations, presence of LST, and ability to detect stability and spread of E. chaffeensis in WTD populations). Of 3275 WTD serologically tested, 549 (47%) from 17 of 18 states had antibodies reactive to E. chaffeensis (IFA titer > or = 1:128). No difference between age groups or gender was noted with serologic testing, thus these variables would not be a concern for a surveillance system using WTD. Significantly more deer in younger age groups (< or = 1.5 yr) were PCR and culture positive, and 46% of 122 seropositive WTD populations were confirmed positive by PCR or culture isolation. A significant association between LST infestation and E. chaffeensis seroreactivity was noted. Furthermore, the surveillance system was able to detect stability of E. chaffeensis within WTD populations and also spread to new populations, both of which were associated with LST status. These data clearly demonstrate that WTD are useful as natural sentinels for this emerging human pathogen, and establish a prototypical framework for a WTD surveillance system.  相似文献   

9.
目的调查新疆地区人、家畜动物包括羊、牛、马及野生动物旱獭、大尾黄鼠及家养马鹿等无形体感染及病原16SrRNA序列特征。方法采集伊犁地区正常人、牛、马、羊及野生啮齿动物大尾黄鼠、旱獭血液。 微量间接免疫荧光检测方法(mIFA)检测血清无形体IgM、IgG抗体。巢氏PCR扩增无形体16SrRNA基因并分析序列特征。结果当地人群无形体IgG抗体阳性率为5.3%;羊、牛及马为6.9%、6.3%及9.1%。 PCR结果发现羊、牛及马无形体16SrRNA基因检出率为38.9%、37.5%及36.4%。16SrRNA(228bp)序列分析显示存在明显变异株,同源比较结果提示这些变异株在我国其他地区及周边国家媒介及动物宿主中均有广泛分布。结论新疆伊犁地区存在人及家畜无形体感染。 开展发热病人无形体实验室调查及进一步人群、媒介种类、宿主与无形体生态学关系研究十分必要。  相似文献   

10.
BACKGROUND: Most epidemiologic studies of tick-borne rickettsial diseases in the United States are small and have limited demographic scope, making broader risk assessment difficult. METHODS: We conducted a seroprevalence study of spotted fever group rickettsiae and Anaplasma phagocytophilum, the agent of human granulocytic anaplasmosis. Specimens were selected randomly from the Department of Defense Serum Repository for 10,000 diverse military personnel at various stages in their careers who were serving with active duty status in 1997. Antibody testing included enzyme-linked immunosorbent assay for Rickettsia rickettsii and A. phagocytophilum, and Western blot confirmation for A. phagocytophilum. Risk factors were assessed using logistic regression. RESULTS: Subjects were mostly male and young and were diverse ethnically and geographically. Spotted fever group rickettsiae seropositivity was 6.0% (95% confidence interval, 5.5%-6.4%). In univariable logistic regression, seroprevalence was significantly higher among older subjects, men (6.5%, compared with 3.3% among women), black individuals (8.7%, compared with 5.6% among white individuals), subjects from states with above-average Rocky Mountain spotted fever incidence, and subjects in ground combat specialties. Associations remained significant in multivariable analysis for age, sex, black versus white race, home state with high incidence, and ground combat specialty. Among 696 subjects with serum samples obtained within 7 days after entering the military, the rate of seropositivity was 3.4% (95% confidence interval, 2.1%-4.8%). Seroprevalence was nonsignificantly lower in men (3.4%, compared with 3.7% in women ) and in black individuals (3.4%, compared with 4.1% in white individuals). A. phagocytophilum seropositivity, as determined by by enzyme-linked immunosorbent assay and Western blot, was 2.6% and 0.11% (95% confidence interval, 0.05%-0.18%), respectively. Western blot seropositivity was not significantly associated with subject characteristics in univariable analysis. CONCLUSIONS: Spotted fever group rickettsiae exposure was common and A. phagocytophilum exposure was rare in a US population with broad demographic diversity.  相似文献   

11.
Organisms in the genus Anaplasma are obligate intracellular pathogens that multiply in both vertebrate and invertebrate hosts. The type species, A. marginale, causes bovine anaplasmosis and only infects ticks and ruminants. A. phagocytophilum causes human and animal granulocytic anaplasmosis, and genetically closely related strains show a wide host range, including ticks, ruminants, rodents, equids, canids, birds, and humans. Recent reports demonstrated that A. marginale and A. phagocytophilum co-exist in geographic areas and that concurrent infections occur in ruminants and ticks. In this study, we characterized A. marginale and A. phagocytophilum infections in wild and domestic animals, and ticks collected in central Spain by serology, PCR, and sequence of 16S rRNA genotypes. Species tested included humans, cattle, dogs, rodents, Iberian red deer, European wild boar, birds, and ticks. Species of hematophagous Diptera were analyzed as potential mechanical vectors of Anaplasma spp. A. marginale was detected in tabanids, ticks, cattle, and deer, while A. phagocytophilum was detected in ticks, deer, cattle, and birds. Concurrent infections of the two Anaplasma were found in cattle and deer. These results illustrate the complexity of the epizootiology of A. marginale and A. phagocytophilum in regions where both pathogens co-exist and share common reservoir hosts and vectors. The increasing contact between wildlife, domestic animals, and human populations increases the risk of outbreaks of human and bovine anaplasmosis, and the difficulty of implementing surveillance and control measures.  相似文献   

12.
目的 嗜吞噬细胞无形体和伯氏疏螺旋体是由媒介蜱传播的引起人粒细胞无形体病和莱姆病的病原。目前,对两种病原在蜱体内共感染流行情况的研究相对较少。方法 以甘肃、湖南和广东三个省采集到3个蜱种、共543份样品为研究对象,检测嗜吞噬细胞无形体和伯氏疏螺旋体在蜱体内的感染情况。结果 嗜吞噬细胞无形体和伯氏疏螺旋体在不同地区采集到的蜱体内的感染率不同,分别为3.2%~20.0%和2.3%~19.3%。在检测的样品中,共发现有7份样品中同时感染嗜吞噬细胞无形体和伯氏疏螺旋体。青海血蜱、血红扇头蜱和微小牛蜱中均检测到这两种病原。结论 青海血蜱、血红扇头蜱和微小牛蜱均能够携带嗜吞噬细胞无形体和伯氏疏螺旋体,可能为这两种病原在自然界的持续存在和循环提供了条件。此研究结果丰富了人粒细胞无形体病和莱姆病的流行病学信息,有利于提高这两种病的防控策略。  相似文献   

13.
A seroprevalence study of Anaplasma infection was conducted in a stratified random sample of goats and sheep in Cyprus in which the sample locations were recorded using a geographical information system (GIS). The aim of the study was to estimate the prevalence of Anaplasma phagocytophilum and other Anaplasma species in sheep and goats, and to identify high-risk regions. A total of 689 serum samples (343 from sheep and 346 from goats) were randomly collected and tested for the detection of antibodies against A. phagocytophilum antigen using an indirect immunofluorescent assay. The polymerase chain reaction followed by sequencing analysis was used for the detection and molecular characterization of Anaplasma sp DNA in the blood samples. The prevalence of IgG antibodies against A. phagocytophilum antigen was 18% for goats, and 31% for sheep. Six new genotypes were detected in goats and sheep; by sequence analysis one was identified as A. phagocytophilum, one as Anaplasma platys and the remaining four as Anaplasma species. The results provide evidence for the presence of A. phagocytophilum and Anaplasma species in sheep and goats in Cyprus.  相似文献   

14.
Ticks are recently regarded as ones of the most important vectors of emerging diseases. One of these diseases is human granulocytic ehrlichiosis caused by obligatory intracellular microorganism recently named as Anaplasma phagocytophilum. 334 sera from forestry workers and 56 sera from blood donors (as a control group) were collected and examined for antibodies to A. phagocytophilum and B. burgdorferi. The antibodies were found statistically more frequently in sera from foresters compared to sera of the control group, both to A. phagocytophilum (19.8% vs. 5.4%, p < 0.001) and B. burgdorferi (32.0% vs. 7.1%, p < 0.01). Only 15 sera (4.5%) were found positive for both examined bacteria suggesting inhibition of coexistence although it was not statistically significant. No correlation was found between percentages of antibodies to A. phagocytophilum and to B. burgdorferi from different locations.  相似文献   

15.
Rabbits have been shown to harbor a suite of zoonotic organisms, including a Babesia species, Borrelia burgdorferi, and Anaplasma phagocytophilum. In this study, we conducted a molecular survey for various tick-borne pathogens in three species of rabbits from Texas and Georgia. Of 18 black-tailed jackrabbits (Lepus californicus) tested from Texas, six (28%) were polymerase chain reaction (PCR) positive for Babesia, and nucleotide sequencing revealed two distinct species or strains. Two jackrabbits were infected with a Babesia species or strain (Babesia sp. A) that was nearly identical (99.9%) to a piroplasm previously detected in humans from Washington state, and the remaining four jackrabbits were infected with a Babesia species (Babesia sp. B) that was most similar (99.7%) to a Babesia species detected in cottontail rabbits from Massachusetts and humans from Kentucky and Missouri. Eleven (61%) black-tailed jackrabbits were positive for A. bovis, and one was positive for A. phagocytophilum. Two of four desert cottontails (Sylvilagus audubonii) from Texas were positive for the Babesia sp. B, and one desert cottontail each was positive for A. bovis and A. phagocytophilum. One of these desert cottontails was coinfected with the Babesia sp. B and A. phagocytophilum, and five jackrabbits were coinfected with Babesia species and A. bovis. Of 19 eastern cottontails (S. floridanus) from Georgia, only one (5.3%) was positive for A. phagocytophilum, and three (15.8%) were positive for A. bovis. No rabbits from Texas or Georgia were positive for Borrelia species. The only tick species detected on the Texas and Georgia rabbits was the rabbit tick, Haemaphysalis leporispalustris. These data extend the geographic and host range of these pathogens, and because both the Babesia species and A. phagocytophilum are potential zoonotic pathogens, it is important to be aware that these organisms are enzootic in parts of the southern United States.  相似文献   

16.
The specimens of 3552 questing adult Ixodes persulcatus and 1698 blood/tissue samples of small mammals collected in Ural, Siberia, and Far East of Russia were assayed for the presence of Anaplasma phagocytophilum by nested PCR based on the 16S rRNA gene. Totally, A. phagocytophilum was detected in 112 tick and 88 mammalian samples. The nucleotide sequences of the 16S rRNA gene and groESL operon (1244-1295?bp) were determined for A. phagocytophilum samples from 65 ticks and 25 small mammals. Six different 16S rRNA gene variants differing by 1-5 nucleotide substitutions were detected, and only one variant matched the sequences deposited in GenBank. Analysis of groESL sequences allowed the A. phagocytophilum samples to be divided into three groups; moreover, the samples from different groups also differed in the 16S rRNA gene sequences. The A. phagocytophilum sequences from group I were detected in 11 Myodes spp. samples from West Siberia and Far East and in 19 I. persulcatus samples from all examined regions; from group II, in 10 samples of Myodes spp. and common shrews (Sorex araneus) from Ural; and from group III, in four samples of Asian chipmunks (Tamias sibiricus) from West Siberia and Far East; and in 46 I. persulcatus samples from all examined regions. The nucleotide sequences of A. phagocytophilum groESL operon from groups I and II were strictly conserved and formed with A. phagocytophilum groESL sequence from a Swiss bank vole (Myodes glareolus) (GenBank accession no. AF192796), a separate cluster on the phylogenetic tree with a strong bootstrap support. The A. phagocytophilum groESL operon sequences from group III differed from one another by 1-4 nucleotides and formed a separate branch in the cluster generated by European A. phagocytophilum strains from roe deer (Capreolus capreolus) and Ixodes ricinus ticks.  相似文献   

17.
Anaplasma phagocytophilum is an emerging pathogen throughout much of the Holarctic, where Ixodes spp. tick vectors occur. This organism was expected to be present at study sites in Humboldt County, north-western California, based on the presence of appropriate tick vectors, seropositivity in sentinel hosts, and previously reported human infections. However, despite high seroprevalence suggesting circulating A. phagocytophilum, active infections in dogs and wildlife (including suspected reservoir species) were rare using published polymerase chain reaction (PCR) protocols. This finding was possible if the published PCR protocol lacked sensitivity for strains in the study areas. We report a new TaqMan-PCR (TM-PCR) assay targeting the msp2 gene that has greater sensitivity and specificity for diverse A. phagocytophilum strains from this region. The new assay detected as few as one plasmid copy and a range of genetically diverse strains of A. phagocytophilum. Specificity was confirmed by failure to amplify targets of closely related bacteria. Application of the TM-PCR to samples from northern California confirmed PCR-positivity in 94 woodrats (71%; n=134), three (4%; n=80) bears, and seven (7%; n=97) domestic dogs. The msp2 TM-PCR protocol appears to be more sensitive for use in assays of samples from parts of western North America and possibly in other regions where populations are genetically diverse or divergent from eastern United States strains of A. phagocytophilum.  相似文献   

18.
This study was conducted to determine the prevalence and geographic distribution of Anaplasma phagocytophilum, the causative agent of human granulocytic anaplasmosis, in wild deer and boars in Japan. We analyzed the blood samples of the study animals using PCR-targeting the 16S rDNA followed by DNA sequencing. Wild deer infected with Anaplasma spp., including Anaplasma bovis and Anaplasma centrale were detected in the region from Hokkaido to Kyushu. The infection rates of A. phagocytophilum, A. bovis, and A. centrale in deer were 15.6, 21.9, and 37.5%, respectively, and the corresponding infection rates in wild boar were 3.6, 17.9, and 3.6%, respectively. However, p44/msp2 genes specific to A. phagocytophilum were not detected among the 16S rDNA-positive samples on PCR analysis. In addition, the 16S rDNA sequences of A. phagocytophilum were 100% similar to those detected previously in the deer in Japan and 98.6% similar to those of A. phagocytophilum detected in the United States and Europe, and from the tick, Ixodes ovatus and Ixodes persulcatus in Japan. These findings suggested that the A. phagocytophilum-related sequences detected from deer and wild boars in Japan were different from those of typical A. phagocytophilum strains.  相似文献   

19.
Anaplasma phagocytophilum is a vector-borne, obligate intracellular bacterium that invades the neutrophils and eosinophils of infected individuals, causing granulocytic anaplasmosis. Equine cases have previously been reported in the United States from California, Florida, and Connecticut, but limited surveillance studies in the Southeast have been conducted. The objective of this study was to determine A. phagocytophilum prevalence in Ixodes scapularis ticks at southeastern U.S. horse-inhabited sites to evaluate the potential risk for equine exposure to A. phagocytophilum-infected ticks in these areas. Samples of I. scapularis were collected from selected barrier islands and Georgia mainland sites where feral and domestic equine populations are present, respectively. Ticks were individually tested for infection by amplification of the A. phagocytophilum ankA gene. The collective prevalence of A. phagocytophilum in I. scapularis ticks was 20% (n=808).  相似文献   

20.
The aim of our study was to investigate the presence of Borrelia burgdorferi sensu lato (s.l.) and Anaplasma phagocytophilum in small mammals and ticks using polymerase chain reaction and to gain information about the prevalence and possible coexistence of these pathogens at a selected site in Hungary. Two hundred seventy-seven small mammals were trapped in South-Eastern Hungary during 2009. Tissue samples and a total of 831 ectoparasites (Ixodes ricinus, Ixodes acuminatus, Haemaphysalis concinna, Ctenophtalmus assimilis, and Nosopsyllus fasciatus) were collected from small mammals. One thousand one hundred and six I. ricinus and 476 H. concinna were collected from the vegetation during the investigation. Neither A. phagocytophilum nor B. burgdorferi s.l. was detected in any of the mammal tissue samples. A. phagocytophilum was not found in ticks collected from small mammals. Very low minimum prevalence was found for all pathogens (0.62% for Borrelia afzelii in ticks collected from small mammals, and 0.57%, 0.06%, and 0.19% for A. phagoctyophilum, B. afzelii, and Borrelia garinii, respectively, in questing ticks). The present study is the first report of borreliae from I. acuminatus and H. concinna from Hungary.  相似文献   

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