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PubMed2006

Molecular analysis of microbial communities identified in different developmental stages of Ixodes scapularis ticks from Westchester and Dutchess Counties, New York.

Ixodes scapularis ticks play an important role in the transmission of a wide variety of pathogens between various mammalian species, including humans. Pathogens transmitted by ticks include Borrelia, Anaplasma and Babesia. Although ticks may harbour both pathogenic and non-pathogenic microflora, little is known about how the diversity of the microflora within ticks may influence the transmission of pathogens. To begin addressing this question, we examined the composition of bacterial communities present in Ixodes scapularis collected from Westchester and Dutchess Counties, New York State, at different developmental and nutritional stages. Genetic fingerprints of bacterial populations were generated by temporal temperature gradient gel electrophoresis (TTGE) separation of individual polymerase chain reaction (PCR)-amplified 16S rRNA gene fragments, followed by DNA sequence analysis for bacterial identification. The fingerprints of the TTGE bands were grouped into five clusters. The most abundant DNA sequence found in all the samples was Rickettsia, followed by Pseudomonas and Borrelia. Ralstonia, Anaplasma, Enterobacterias, Moraxella, Rhodococcus and uncultured proteobacterium were present as well. We also determined the prevalence of Anaplasma phagocytophilum and Borrelia burgdorferi by PCR and DNA sequence analysis. Statistical analyses indicated significant variations in the bacterial communities depending on tick developmental stage and degree of engorgement. We suggest that these two elements affect microbial diversity within the tick and may in turn influence pathogen transmission to humans and animals after tick bite.

Animals↗

PubMed2003

Predominance of Ehrlichia ewingii in Missouri dogs.

To investigate the species distribution of Ehrlichia present in Missouri dogs, we tested 78 dogs suspected of having acute ehrlichiosis and 10 healthy dogs. Blood from each dog was screened with a broad-range 16S rRNA gene PCR assay that detects known pathogenic species of Ehrlichia and ANAPLASMA: The species was determined by using species-specific PCR assays and nucleotide sequencing. Ehrlichia antibody testing was performed by using an indirect immunofluorescence assay with Ehrlichia chaffeensis as the antigenic substrate. The broad-range assay detected Ehrlichia or Anaplasma DNA in 20 (26%) of the symptomatic dogs and 2 (20%) of the asymptomatic dogs. E. ewingii accounted for 20 (91%), and E. chaffeensis accounted for 1 (5%) of the positives. Anaplasma phagocytophilum DNA was detected in one dog, and the sequences of regions of the 16S rRNA gene and the groESL operon amplified from the blood of this dog matched the published sequences of this organism. Antibodies reactive with E. chaffeensis were detected in 14 (67%) of the 21 PCR-positive dogs and in 12 (19%) of the 64 PCR-negative dogs. Combining the results of PCR and serology indicated that 33 (39%) of 85 evaluable dogs had evidence of past or current Ehrlichia infection. We conclude that E. ewingii is the predominant etiologic agent of canine ehrlichiosis in the areas of Missouri included in this survey. E. canis, a widely recognized agent of canine ehrlichiosis, was not detected in any animal. The finding of E. ewingii in asymptomatic dogs suggests that dogs could be a reservoir for this Ehrlichia species.

Animals↗

PubMed2003

Detection of Ehrlichia spp. in the blood of wild white-tailed deer in Missouri by PCR assay and serologic analysis.

Blood samples collected from wild deer in Missouri in November of 2000 and 2001 were positive by PCR assays for Ehrlichia chaffeensis (50 of 217; 23%), Ehrlichia ewingii (44 of 217; 20%), and Anaplasma species (214 of 217; 99%). Nucleotide sequences of selected amplicons from the assay for anaplasma matched sequences of the white-tailed deer agent. Serologic analysis of 112 deer sampled in 2000 showed a very high prevalence of antibodies to E. chaffeensis (97 of 112; 87%) and a low prevalence of antibodies reactive with Anaplasma phagocytophila (2 of 112; 2%).

Animal Diseases↗

PubMed2005

Detection and identification of Ehrlichia spp. in ticks collected in Tunisia and Morocco.

A broad-range 16S rRNA gene PCR assay followed by partial sequencing of the 16S rRNA gene was used for the detection of members of the family Anaplasmataceae in ticks in North Africa. A total of 418 questing Ixodes ricinus ticks collected in Tunisia and Morocco, as well as 188 Rhipicephalus ticks from dogs and 52 Hyalomma ticks from bovines in Tunisia, were included in this study. Of 324 adult I. ricinus ticks, 16.3% were positive for Ehrlichia spp., whereas only 3.4 and 2.8% of nymphs and larvae, respectively, were positive. A large heterogeneity was observed in the nucleotide sequences. Partial sequences identical to that of the agent of human granulocytic ehrlichiosis (HGE) were detected in I. ricinus and Hyalomma detritum, whereas partial sequences identical to that of Anaplasma platys were detected in Rhipicephalus sanguineus. However, variants of Anaplasma, provisionally designated Anaplasma-like, were predominant in the I. ricinus tick population in Maghreb. Otherwise, two variants of the genus Ehrlichia were detected in I. ricinus and H. detritum. Surprisingly, a variant of Wolbachia pipientis was evidenced from I. ricinus in Morocco. These results emphasized the potential risk of tick bites for human and animal populations in North Africa.

Anaplasmataceae↗

PubMed2006

Tick-transmitted diseases in dogs: clinicopathological findings.

In this article we describe the main clinicopathological findings of some tick-transmitted diseases observed in Italy, due to Ehrlichia canis and Babesia canis, and most rarely Anaplasma phagocytophilum and Anaplasma platys. Canine monocytic ehrlichiosis (CME) is a multisystemic disorder that is characterized by various clinical signs. Acutely-infected dogs show various clinical and haematological abnormalities including fever, lymphadenopathy, anorexia, lethargy, depression and thrombocytopenia. Many dogs with CME evolve in to an asymptomatic or chronically symptomatic carrier states. In Italy there are very few cases of Canine Granulocytic Ehrlichiosis (CGE) and all are attributed to A. phagocytophilum. The early manifestations of CGE are usually mild and consist in acute onset of fever and depression with or without thrombocytopenia. Lameness due to polyarthritys is also possible. Other clinical manifestations most rarely described are very similar to those reported in chronic form of E. canis infections. There are very few studies about clinicopathological findings of canine babesiosis in Italy. In our country this infection is caused by Babesia canis (large form of parasite) subspecies B. canis canis and B. canis vogeli. These two subspecies are morphologically indistinguishable. Clinical signs reflect the intravascular and extravascular haemolysis due to the life cycle of the parasite. The most common haematological abnormalities found in canine babesiosis are anaemia and thrombocytopenia. It is important to point out that co-infection between two or more agents is possible. In this case it is very difficult to attribute the clinical signs and haematological and/or biochemical abnormalities to a single specific agent.

Anaplasma↗

PubMed2006

Rickettsial agents from parasitic dermanyssoidea (Acari: Mesostigmata).

Mites are often overlooked as vectors of pathogens, but have been shown to harbor and transmit rickettsial agents such as Rickettsia akari and Orientia tsutsugamushi. We screened DNA extracts from 27 mites representing 25 species of dermanyssoids for rickettsial agents such as Anaplasma, Bartonella, Rickettsia, and Wolbachia by PCR amplification and sequencing. DNA from Anaplasma spp., a novel Bartonella sp., Spiroplasma sp., Wolbachia sp., and an unclassified Rickettsiales were detected in mites. These could represent mite-borne bacterial agents, bacterial DNA from blood meals, or novel endosymbionts of mites.

Anaplasma↗

PubMed2026

Hemotropic mono- and coinfections in Colombian ruminants: descriptive occurrence and host-related factors associated with coinfection in cattle.

Hemotropic pathogens such as Anaplasma, Babesia, Mycoplasma, and Trypanosoma are endemic to cattle and can cause coinfections, complicating disease dynamics and control. However, the host-related factors influencing these infections under tropical conditions remain poorly understood. This study aimed to investigate the occurrence of hemotropic monoinfections and coinfections in ruminants tested for hemotropic pathogens and to identify host-related factors associated with coinfection in cattle under field conditions in Colombia. A total of 104 animals were included: 91 cattle, 10 buffaloes, and 3 goats. Among the cattle, 34 (37.4%) exhibited monoinfections, 47 (51.6%) had coinfections, and 10 tested negative. In buffaloes, seven (70%) presented monoinfections, and two (20%) presented coinfections; in goats, one had a monoinfection, and one had a coinfection, most frequently involving Mycoplasma spp. The predominant coinfection patterns were Anaplasma + Mycoplasma and Mycoplasma + Trypanosoma, particularly in Bos indicus cattle. Bivariate and multivariable analyses revealed that breed was the strongest predictor of coinfection, with animals of less common breeds showing 93% lower odds (aOR = 0.07; 95% CI: 0.02-0.30; p < 0.001). Bos taurus individuals also tended toward lower odds of coinfection in the multivariable model, although this trend did not reach statistical significance. Our findings demonstrate a high frequency of hemotropic coinfections in cattle, particularly those involving Mycoplasma spp., and highlight the influence of host-related factors on infection dynamics. These results underscore the importance of integrating demographic and genetic information into surveillance and prevention strategies to improve the management of hemotropic infections in tropical livestock systems.

Animals↗

PubMed1983

Observations on anaplasmosis following field exposure to heavy and light infestations with Boophilus microplus.

Two groups of Normandy calves were exposed to heavy (mean half body count = greater than 300) or light (mean half body count = 9) natural infestations with Boophilus microplus. All of the calves became infected with Anaplasma marginale. Despite the difference in tick challenge level, there was no significant difference in the incubation period, increase in body temperature, level or duration of Anaplasma parasitemia, decrease in packed cell volume, or complement-fixing antibody response, between the heavily and lightly infected calves. Neither the incubation period nor the clinical severity of anaplasmosis was significantly influenced by the number of infested tick vectors.

Anaplasma↗

PubMed1985

Observations on erythrocytic acetylcholinesterase activity in experimentally induced anaplasmosis in calves.

Erythrocytic acetylcholinesterase (AChE) activity was assessed in splenectomized bovine calves inoculated with Anaplasma marginale. Other parameters, i.e., haematological values (haemoglobin, packed-cell volume, and total erythrocytic count), percentage parasitaemia and the ensuing host reactions during Anaplasma infection were also studied in relation to AChE activity. There was significant inhibition of red blood cell-AChE activity commencing soon after inoculation of infected blood; this preceded a substantial decrease in haematological values along with high parasitaemia. The changes in AChE activity may possibly be associated with increased cell membrane permeability, thus triggering the entry of A. marginale organisms into red blood cells.

Acetylcholinesterase↗

PubMed1995

Live vaccines against hemoparasitic diseases in livestock.

Live vaccines against hemoparasitic diseases in livestock are based on parasites derived from culture (Theileria annulata), from blood of infected animals (Babesia bovis, Babesia bigemina, Anaplasma centrale, (attenuated) Anaplasma marginale and Cowdria ruminantium), and from ticks (Theileria parva). The T. annulata attenuated cultured schizont vaccine is safe for all varieties of cattle. Blood derived vaccines are recommended mainly for young cattle, the age limit varying with the different vaccines and breeds of cattle. In older animals, monitoring of the individual response is needed. Immunization against T. parva requires simultaneous or postinoculation chemotherapy. The potential for accidental transmission of disease agents exists with all blood derived vaccines. Various degrees of resistance to field infection have been reported in animals immunized with live vaccines. Nevertheless, all of them engender a level of protection against natural challenge that justifies their use in field vaccination. Chemotherapy or chemoprophylaxis may prevent establishment of infection with the vaccinal parasites, and thus may interfere with elaboration of immunity. Outbreaks of disease in vaccinated herds, caused by antigenic variants among the tick-transmitted parasites, have been observed mainly in Babesia infections. In recent years, the main efforts towards improvement of live vaccines have been in the direction of replacing blood- and tick-derived parasites by those cultured in vitro under controlled standardized conditions.

Anaplasma↗

PubMed2005

Seroprevalence of anaplasmosis among cattle in Switzerland in 1998 and 2003: no evidence of an emerging disease.

Anaplasma marginale infection in Europe has been limited to the Mediterranean and eastern countries, to Austria and to very sporadic cases in Switzerland. There are no reports of its occurrence in the countries north of Switzerland. A severe outbreak of anaplasmosis in August 2002 in a cattle farm in the canton Grisons, Switzerland, north of the Alps, with more than 300 cattle that had to be culled, came unexpected and gave reason to hypothesize presence of an increased yet undetected prevalence of A. marginale in Switzerland. Randomly selected bovine serum samples collected in 1998 and 2003 were tested using a competitive inhibitory ELISA (cELISA) to test the hypothesis. Our validation of the diagnostic sensitivity and specificity of this test, done in the outbreak herd, yielded 99.2 and 83.3%, respectively, probably underestimating the true specificity. The true seroprevalence of anaplasmosis in Swiss cattle determined by cELISA was likely to be zero with upper 95% confidence limits of 2.49% in the canton Grisons and 1.17% in the rest of Switzerland, respectively, in 1998. For 2003, these estimates were even lower. There was no significant difference in apparent prevalences between 1998 and 2003. In search of a possible reservoir, three chamoises out of 46 free ranging wild ruminants from the Swiss National Park, Grisons, tested positive in the cELISA. This reaction is in accordance with A. marginale or a cross reacting agent such as Anaplasma ovis. From our results we conclude that the hypothesis of an increased prevalence of anaplasmosis in cattle in Switzerland must be rejected.

Anaplasma marginale↗

PubMed2003

Ehrlichiosis and related infections.

Ehrlichiosis is a term that has been used to describe infection with any of a number of related intracellular, vector-borne pathogens. A recent reclassification has resulted in the transfer of several species previously known as Ehrlichia to the genus Anaplasma or Neorickettsia. Ehrlichia and Anaplasma are transmitted largely through the bite of infected ticks, while vectors for Neorickettsia include trematodes and the intermediate hosts (i.e., fish, snails, and insects) involved in the trematode life cycle. Dogs (and cats) are susceptible to infection with several of these pathogens, and veterinarians should be aware of the similarities and differences between E canis and related infections. Pets with suggestive clinical signs and laboratory abnormalities may be started on doxycycline pending specific diagnostic testing. The veterinarian practicing in endemic areas must understand the implications and limitations of serologic and molecular testing to confirm a diagnosis. For animals in endemic areas, prevention of exposure to vectors can lessen the risk of disease for pets and might lessen the potential for animals to become carriers of disease for their human companions.

Anaplasma↗

PubMed2001

Detection of haemoparasites in cattle by reverse line blot hybridisation with a note on the distribution of ticks in Sicily.

A reverse line blot hybridisation (RLB) of 21 oligonucleotides with polymerase chain reaction (PCR) amplified regions of 16S rRNA (Ehrlichia/Anaplasma group) or 18S rRNA (Babesia/Theileria group) genes of haemoparasites detected Theileria annulata, T. buffeli/orientalis, Babesia bovis, B. bigemina, B. divergens, Ehrlichia bovis, Anaplasma marginale, A. centrale and unknown species within the Rickettsia tribe.A very high prevalence of mixed infections was detected, which indicated that animals infected with Babesia spp. were also infected with Theileria spp. and/or Anaplasma spp. The tick distribution appeared to be seasonal with Hyalomma marginatum as the most frequently observed tick and Boophilus annulatus and Ixodes ricinus as the least frequently observed ticks. Other species identified in the 818 ticks collected during the five sampling periods between April 1998 and November 1999 included H. lusitanicum, Rhipicephalus sanguineus group, R. bursa, Dermacentor marginatus, Haemaphysalis punctata, B. annulatus and I. ricinus.

Anaplasma↗

PubMed1990

The indirect fluorescent antibody test for bovine anaplasmosis.

An indirect fluorescent antibody test was used successfully for the serodiagnosis of experimental Anaplasma infections in cattle. Specific antibodies were detected three to ten days after anaplasma bodies were found in the blood, and persisted at least 15 weeks post-infection. An American and an African stock of A. marginale were used to prepare antigens, and gave comparable results when tested on sera positive to either of these stocks, as well as to an A. central-like stock from Korea. There were no cross-reactions with several Theileria, Babesia, Trypanosoma and Eperythrozoon species.

Anaplasma↗

PubMed2005

Environmental factors associated with Bartonella vinsonii subsp. berkhoffii seropositivity in free-ranging coyotes from northern California.

Bartonella vinsonii subsp. berkhoffii is a newly recognized pathogen of domestic dogs and humans. Coyotes (Canis latrans) are considered an important reservoir of this bacterium in the western United States, but its vectors are still unknown. Our objective was to identify environmental factors associated with Bartonella antibody prevalence in 239 coyotes from northern California, using an enzyme-linked immunosorbent assay. In addition, associations were evaluated between B. v. berkhoffii and two pathogens with known vectors and habitat requirements, Dirofilaria immitis and Anaplasma phagocytophilum. Overall, B. v. berkhoffii seroprevalence was 28% (95% confidence interval [CI], 22.3%, 33.7%) and Bartonella seropositive coyotes were more likely than seronegative coyotes to be positive for Anaplasma phagocytophilum (Odds ratio = 3.3; 95% CI = 1.8, 5.9) and Dirofilaria immitis (Odds ratio = 2.1; 95% CI = 1.2, 3.8). The most likely geographic clusters of Bartonella and Dirofilaria overlapped. Bartonella seropositivity was associated with higher precipitation (p = 0.003) and proximity to the coast (p = 0.007) in univariate analysis. The association with precipitation varied with season, based on a logistic regression model.

Anaplasma phagocytophilum↗

PubMed2005

Detection of Ehrlichia spp. in raccoons (Procyon lotor) from Georgia.

Raccoons (Procyonis lotor) and opossums (Didelphis virginianus) acquired from six contiguous counties in the Piedmont physiographic region of Georgia were investigated for their potential role in the epidemiology of ehrlichial and anaplasmal species. Serum was tested by indirect fluorescent antibody (IFA) assay for the presence of antibodies reactive to Ehrlichia chaffeensis, E. canis, and Anaplasma phagocytophilum (HGA agent). Nested polymerase chain reaction (PCR) assay was used to test whole blood or white blood cell preparations for the presence of Ehrlichia and Anaplasma spp. 16S rRNA (rDNA) gene fragments. In addition, ticks were collected from these animals and identified. Twenty-three of 60 raccoons (38.3%) had E. chaffeensis-reactive antibodies (>1:64), 13 of 60 raccoons (21.7%) had E. canis-reactive antibodies, and one of 60 raccoons (1.7%) had A. phagocytophilum- reactive antibodies. A sequence confirmed E. canis product was obtained from one of 60 raccoons and a novel Ehrlichia-like 16S rDNA sequence was detected in 32 of 60 raccoons. This novel sequence was most closely related to an Ehrlichia-like organism identified from Ixodes ticks and rodents in Asia and Europe. Raccoons were PCR negative for E. chaffeensis and E. ewingii DNA. Five tick species, including Dermacentor variabilis, Amblyomma americanum, Ixodes texanus, I. cookei, and I. scapularis, were identified from raccoons and represent potential vectors for the ehrlichiae detected. Opossums (n = 17) were free of ticks and negative on all IFA and PCR assays. This study suggests that raccoons are potentially involved in the epidemiology of multiple ehrlichial organisms with known or potential public health and veterinary implications.

Anaplasma↗

PubMed2001

Immunity following use of Australian tick fever vaccine: a review of the evidence.

OBJECTIVE: To review the evidence available on the degree and duration of immunity provided by Australian tick fever vaccines against Babesia bovis, B. bigemina and Anaplasma marginale infections in Australia and overseas. BACKGROUND: Vaccines containing attenuated strains of B bovis and B bigemina as well as A. centrale grown in splenectomised calves have been used in Australia since 1964 to immunise cattle against tick fever. About 800,000 doses of vaccine are supplied annually and much of the evidence for protection is field evidence rather than conventional immunological measures or pen trials. CONCLUSIONS: Immunity to Babesia bovis and B. bigemina--A single inoculation generally provides sound, long-lasting protection both in Australia and overseas. No evidence was found of a loss of immunity with time. Vaccine failures to B. bovis do occur, but are uncommon and evidently caused by a number of factors, including immune responsiveness of the vaccinated animals, and immunogenicity of the vaccine strain. Immunity to Anaplasma marginale--The vaccine containing A. centrale provides partial, variable protection against A. marginale. Protection against challenge in Australia is adequate in most cases to prevent disease and use of the vaccine in this country appears to be justified. Protection against antigenically diverse, highly virulent stocks of A. marginale in other countries is, at times, clearly inadequate and better vaccines are required in situations where the challenge is severe.

Anaplasma↗

PubMed1960

Detection of an Amplasma marginale antibody complex formed in vivo.

A naturally occurring anaplasma-antibody complex was detected by exposing erythrocytes of infected cattle to fluorescein-labeled bovine antiglobulin. This technique revealed not only the classical marginal bodies but also the initial Anaplasma bodies in the erythrocytes of acutely infected animals. Singly occurring initial bodies were observed in the erythrocytes of healthy carriers.

Anaplasma↗