| amblyomma americanum: a potential vector of human ehrlichiosis. | polymerase chain reaction primers specific for ehrlichia chaffeensis were used to amplify dna from extracts of pooled ticks. amplification was performed on extracts from 140 pools (1,579 total ticks) consisting of three tick genera collected from five states. the characteristic 389-basepair product was observed after amplification of extracts from seven different pools of adult amblyomma americanum (117 pools, 1,462 ticks), but not from pools of nymphs. no specific product was observed after amp ... | 1993 | 8357086 |
| hemocytic rickettsia-like organisms in ticks: serologic reactivity with antisera to ehrlichiae and detection of dna of agent of human granulocytic ehrlichiosis by pcr. | ixodid ticks were collected from connecticut, massachusetts, missouri, pennsylvania, rhode island, and british columbia (canada) during 1991 to 1994 to determine the prevalence of infection with hemocytic (blood cell), rickettsia-like organisms. hemolymph obtained from these ticks was analyzed by direct and indirect fluorescent antibody (fa) staining methods with dog, horse, or human sera containing antibodies to ehrlichia canis, ehrlichia equi, or rickettsia rickettsii. of the 693 nymphal and a ... | 1995 | 8567911 |
| characterization of an immunoreactive protein from the agent of human granulocytic ehrlichiosis. | a gene that is homologous to the ehrlichia chaffeensis groel operon was recovered and characterized by broad-range pcr amplification of whole blood from patients with human granulocytic ehrlichiosis (hge) and from infected hl60 cell cultures. sequence analysis of an 820-bp dna fragment recovered directly from human blood showed 76.5 and 76.3% identity with cognate sequences from e. chaffeensis and cowdria ruminantium, respectively. analysis of a 1.6-kb dna fragment derived from an hge agent-infe ... | 1997 | 9114402 |
| natural coinfection of a white-tailed deer (odocoileus virginianus) population with three ehrlichia spp. | the ticks amblyomma americanum and ixodes scapularis, strongly implicated vectors of ehrlichia chaffeensis and the human granulocytic ehrlichiosis (hge) agent, respectively, commonly are found on white-tailed deer (odocoileus virginianus). as deer can be infected with e. chaffeensis, the hge agent, and another ehrlichia-like organism, a deer population parasitized by both tick species in coastal georgia was tested for evidence of ehrlichia spp. infection using serologic, molecular, and culture t ... | 1998 | 9794627 |
| prevalence of infection in ticks submitted to the human tick test kit program of the u.s. army center for health promotion and preventive medicine. | in 1997, ticks removed from humans and received alive by the tick-borne disease laboratory of the u.s. army center for health promotion and preventive medicine (usachppm) were tested for pathogens by polymerase chain reaction (pcr). thirty-three of 222 (15%) amblyomma americanum (l.) dnas produced amplicons of the expected size of ehrlichia chaffeensis anderson, dawson & wilson and 26/222 (12%) produced amplicons indicating borrelia burgdorferi johnson, schmid, hyde, steigalt & brenner. five (2% ... | 2001 | 11268694 |
| risk of lyme disease: perceptions of residents of a lone star tick-infested community. | lone star ticks (amblyomma americanum) have been suggested as a vector of the agent of lyme disease (borrelia burgdorferi sensu lato) in the usa, based on associations with an infection manifesting mainly as erythema migrans. in laboratory experiments, however, they failed to transmit b. burgdorferi sensu stricto. | 2001 | 11693973 |
| acarologic risk of exposure to emerging tick-borne bacterial pathogens in a semirural community in northern california. | an acarologic study was conducted in a semirural community in northern california to determine the relative abundance of, and the prevalence of infection with, three emerging bacterial pathogens in the western black-legged tick (ixodes pacificus). these included the agents causing lyme disease (borrelia burgdorferi), human granulocytic ehrlichiosis [ehrlichia phagocytophila (formerly ehrlichia equi)], and human monocytic ehrlichiosis (ehrlichia chaffeensis). the study area in sonoma county consi ... | 2001 | 12653148 |
| survey of ticks collected in mississippi for rickettsia, ehrlichia, and borrelia species. | from november 1999 through october 2000, we tested ticks collected from vegetation as well as from deer, dogs, and humans for spotted fever group (sfg) rickettsiae, ehrlichia chaffeensis, and borrelia spp. spirochetes. a total of 149 adult ticks representing four species was collected from 11 collection sites from southwestern to northern mississippi. amblyomma americanum was most commonly collected (n=68), followed by ixodes scapularis (n=53). the bird tick, ixodes brunneus (usually rare), was ... | 2003 | 14714667 |
| human behaviors elevating exposure to ixodes pacificus (acari: ixodidae) nymphs and their associated bacterial zoonotic agents in a hardwood forest. | epidemiological evidence suggests that the nymph of the western black-legged tick, ixodes pacificus cooley and kohls, is the primary vector of the lyme disease spirochete, borrelia burgdorferi johnson, schmid, hyde, steigerwalt, and brenner, to humans in northwestern california. in spring 2002, six different human behaviors were evaluated as potential risk factors for acquiring i. pacificus nymphs in a deciduous woodland in mendocino county, california. also, the prevalence of b. burgdorferi sen ... | 2004 | 15061284 |
| anaplasma phagocytophilum has a functional msp2 gene that is distinct from p44. | the msp2 and p44 genes encode polymorphic major outer membrane proteins that are considered unique to the intraerythrocytic agent of anaplasma marginale and the intragranulocytic agent of anaplasma phagocytophilum, respectively. in the present study, however, we found an msp2 gene in a. phagocytophilum that was remarkably conserved among a. phagocytophilum strains from human granulocytic anaplasmosis (hga) patients, ticks, and a horse from various regions in the united states, but the gene was d ... | 2004 | 15213131 |
| unique macrophage and tick cell-specific protein expression from the p28/p30-outer membrane protein multigene locus in ehrlichia chaffeensis and ehrlichia canis. | ehrlichia chaffeensis and ehrlichia canis are tick-transmitted rickettsial pathogens that cause human and canine monocytic ehrlichiosis respectively. we tested the hypothesis that these pathogens express unique proteins in response to their growth in vertebrate and tick host cells and that this differential expression is similar in closely related ehrlichia species. evaluation of nine e. chaffeensis isolates and one e. canis isolate demonstrated that protein expression was host cell-dependent. t ... | 2006 | 16922866 |
| laboratory maintenance of ehrlichia chaffeensis and ehrlichia canis and recovery of organisms for molecular biology and proteomics studies. | tick-borne illnesses are emerging as a major concern for human health in recent years. these include the human monocytic ehrlichiosis caused by the amblyomma americanum tick-transmitted bacterium, ehrlichia chaffeensis; human ewingii ehrlichiosis caused by ehrlichia ewingii (also transmitted by a. americanum ticks); and human granulocytic anaplasmosis caused by the ixodes scapularis tick-transmitted pathogen, anaplasma phagocytophilum. likewise, tick-borne rickettsial pathogens are also a major ... | 2008 | 18770537 |
| ticks and tick-borne pathogens and putative symbionts of black bears (ursus americanus floridanus) from georgia and florida. | ticks were collected from 38 black bears (ursus americanus floridanus) from northwestern florida (n = 18) from 2003 to 2005 and southern georgia (n = 20) in 2006. five species (amblyomma americanum, a. maculatum, dermacentor variabilis, ixodes scapularis, and i. affinis) were collected from florida bears, and 4 species (a. americanum, a. maculatum, d. variabilis, i. scapularis) were collected from bears in georgia. ixodes scapularis was the most frequently collected tick, followed by d. variabil ... | 2009 | 19413369 |
| prevalence of ehrlichia chaffeensis and ehrlichia ewingii in ticks from tennessee. | human ehrlichiosis is the second most common tick-borne disease reported in tennessee after rocky mountain spotted fever. two closely related ehrlichiae, ehrlichia chaffeensis and ehrlichia ewingii, are both causative agents of human disease and are transmitted by amblyomma americanum, the lone star tick. prevalence rates and distribution patterns of these pathogens among ticks in tennessee are currently unknown. to understand prevalence and exposure risk of ehrlichia spp., we tested 616 ticks ( ... | 2010 | 19877819 |
| [ehrlichiosis/anaplasmosis]. | ehrlichiosis and anaplasmosis are zoonoses caused by bacteria from the family anaplasmataceae, including human and animal pathogens. the human pathogens are ehrlichia chaffeensis, the causative agent of human monocytic ehrlichiosis (hme), anaplasma phagocytophilum, the pathogen causing human granulocytic anaplasmosis (hga), e. ewingii and neorickettsia sennetsu, granulocytotropic and monocytotropic ehrlichia species, respectively. ehrlichia spp. are small, gram-negative, obligate intracellular b ... | 2009 | 20077398 |
| bacterial pathogens in ixodid ticks from a piedmont county in north carolina: prevalence of rickettsial organisms. | in north carolina, reported human cases of tick-borne illness, specifically rocky mountain spotted fever, have escalated over the past decade. to determine the relative abundance of vectors and to estimate the risk of acquiring a tick-borne illness in peri-residential landscapes, ticks were collected in chatham county, a typical piedmont county and, samples of the ticks were tested for infection with selected bacterial pathogens using real-time quantitative polymerase chain reaction assays. tick ... | 2010 | 20455778 |
| emergence of a new pathogenic ehrlichia species, wisconsin and minnesota, 2009. | ehrlichiosis is a clinically important, emerging zoonosis. only ehrlichia chaffeensis and e. ewingii have been thought to cause ehrlichiosis in humans in the united states. patients with suspected ehrlichiosis routinely undergo testing to ensure proper diagnosis and to ascertain the cause. | 2011 | 21812671 |
| saliva, salivary gland, and hemolymph collection from ixodes scapularis ticks. | ticks are found worldwide and afflict humans with many tick-borne illnesses. ticks are vectors for pathogens that cause lyme disease and tick-borne relapsing fever (borrelia spp.), rocky mountain spotted fever (rickettsia rickettsii), ehrlichiosis (ehrlichia chaffeensis and e. equi), anaplasmosis (anaplasma phagocytophilum), encephalitis (tick-borne encephalitis virus), babesiosis (babesia spp.), colorado tick fever (coltivirus), and tularemia (francisella tularensis) (1-8). to be properly trans ... | 2012 | 22371172 |
| the prevalence of zoonotic tick-borne pathogens in ixodes scapularis collected in the hudson valley, new york state. | ixodes scapularis, the blacklegged tick, is capable of transmitting the pathogens that cause lyme disease (borrelia burgdorferi), babesiosis (babesia microti), anaplasmosis (anaplasma phagocytophilum), and to a lesser extent powassan encephalitis (deer tick virus [dtv]). these pathogens represent significant public health problems, but little is known about the occurrence and co-infection prevalence of these pathogens in i. scapularis. here, we used standard pcr and pathogen-specific primers to ... | 2014 | 24689680 |
| detection of borrelia miyamotoi and other tick-borne pathogens in human clinical specimens and ixodes scapularis ticks in new york state, 2012-2015. | borrelia miyamotoi (bm) is a recently emerging bacterial agent transmitted by several species of ixodid ticks. diagnosis of bm infection can be challenging, as the organism is not easily cultivable. we have developed and validated a multiplex real-time pcr to simultaneously identify bm infection and the agents causing human granulocytic anaplasmosis and human monocytic ehrlichiosis, anaplasma phagocytophilum and ehrlichia chaffeensis, respectively. the assay is 100% specific; highly sensitive, d ... | 2017 | 28131594 |
| risk of encountering ticks and tick-borne pathogens in a rapidly growing metropolitan area in the u.s. great plains. | the prevalence of tick-borne diseases has increased dramatically in many urban areas of the u.s., yet little is known about the ecology of ticks and tick-borne pathogens in relation to characteristics of north american urban and suburban landscapes. this study aimed to begin identification of the risk of encountering ticks and tick-borne pathogens within a rapidly expanding metropolitan area in the u.s. great plains region. ten sites across oklahoma city, oklahoma were selected for tick sampling ... | 2017 | 27773826 |
| prevalence of babesia spp., ehrlichia spp., and tick infestations in oklahoma black bears (ursus americanus). | american black bears (ursus americanus) are commonly infested with ticks throughout their range, but there are few surveys for tick-borne disease agents in bears. to characterize tick infestations and determine the prevalence of current infection with babesia spp. and past or current infection with ehrlichia spp. in newly re-established populations of black bears in east central and southeastern oklahoma, we identified adult (n=1,048) and immature (n=107) ticks recovered from bears (n=62). we ev ... | 2017 | 28657860 |