PCR detection of Anaplasma platys in blood and tissue of dogs during acute phase of experimental infection

Eddlestone, Susan M.; Gaunt, Stephen D.; Neer, T.M.; Boudreaux, Charles M.; Gill, Amy F.; Haschke, E; Corstvet, Richard E.

doi:10.1016/j.exppara.2006.08.006

Cited by 33 publications

(31 citation statements)

References 25 publications

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“…The acute phase of experimental CME begins approximately 10 days postinoculation (dpi) and involves leukopenia, thrombocytopenia, fever, depression, and anorexia. Notably, reports of experimental infection with E. canis document that dogs presented signs of severe acute CME when they were inoculated with carrier blood (8,20,23,24,42,57) while other investigators reported less severe disease when dogs were inoculated with E. canis-infected cell cultures (17,20,28,30,40). Clinical signs subside approximately 20 to 30 dpi, which is usually followed by a subclinical phase that can last from months to years.…”

mentioning

confidence: 99%

Efficacy of a Doxycycline Treatment Regimen Initiated during Three Different Phases of Experimental Ehrlichiosis

McClure

Crothers

Schaefer

et al. 2010

Antimicrob Agents Chemother

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Doxycycline is the treatment of choice for canine monocytic ehrlichiosis (CME), a well-characterized disease and valuable model for tick-borne zoonoses. Conflicting reports of clearance of Ehrlichia canis after treatment with doxycycline suggested that the disease phase during which treatment is initiated influences outcomes of these treatments. The purpose of this study was to evaluate the efficacy of a 28-day doxycycline regimen for clearance of experimental E. canis infections from dogs treated during three phases of the disease. Ten dogs were inoculated with blood from E. canis carriers and treated with doxycycline during acute, subclinical, or chronic phases of CME. Daily rectal temperatures and semiweekly blood samples were monitored from each dog, and Rhipicephalus sanguineus ticks were acquisition fed on each dog for xenodiagnosis. Blood collected from dogs treated during acute or subclinical CME became PCR negative for E. canis as clinical parameters improved, but blood samples collected from dogs treated during chronic CME remained intermittently PCR positive. R. sanguineus ticks fed on dogs after doxycycline treatments became PCR positive for E. canis, regardless of when treatment was initiated. However, fewer ticks became PCR positive after feeding on two persistently infected dogs treated with doxycycline followed by rifampin, suggesting that antibiotic therapy can reduce tick acquisition of E. canis.

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mentioning

confidence: 99%

Efficacy of a Doxycycline Treatment Regimen Initiated during Three Different Phases of Experimental Ehrlichiosis

McClure

Crothers

Schaefer

et al. 2010

Antimicrob Agents Chemother

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show abstract

“…Both experimental and field studies have pointed out the utility of molecular laboratory diagnosis for sensitive and specific identification of Anaplasma infections (Eriks et al 1989, Palmer et al 1998, Eddlestone et al 2007, Haigh et al 2008, Hing et al 2014. The growing number of highperformance molecular protocols with increased potential for automation and multiplex detection has resulted in these becoming indispensable laboratory tools.…”

Section: Molecular Detectionmentioning

confidence: 99%

“…However, it has limited value in persistently infected animals that usually present low-level bacteremia (Eriks et al 1989, Palmer et al 1998, Kocan et al 2010. For A. platys, light microscopy presents low sensitivity due to the cyclic character of thrombocytopenia and the low percentage of infected cells (between 0.5% and 5%); therefore, it is recommended to examine between 2,000 and 20,000 platelets (Kontos et al 1991, Chang et al 1996, Brown et al 2006, Eddlestone et al 2007). For the granulocytotropic species, morulae can also be sparsely distributed and difficult to detect, particularly in human samples from which at least 800-1,000 granulocytes should be examined (Aguero-Rosenfeld 2002), although at least one study demonstrates identification in all human cases after examination of only 200 granulocytes (Rand et al 2014).…”

Section: Microscopymentioning

confidence: 99%

“…Ethylenediaminetetraacetic acid or citrate are preferred to heparin as anticoagulant, since the latter is considered to interfere with PCR (Hebels et al 2014, Sánchez-Fito andOltra 2015). Spleen samples are equally good and highly recommended for persistently infected animals, especially in wildlife studies or as an additional sample to rule out intermittent or low-level bacteremia in bloodnegative individuals (Eddlestone et al 2007). Other samples reported in the literature with variable results for Anaplasma screening include serum/plasma, liver, lung, lymph nodes, bone marrow, and skin biopsies (Massung et al 1998, Eddlestone et al 2007, Gaunt et al 2010, Blaňarová et al 2014, Szekeres et al 2015.…”

Section: Molecular Detectionmentioning

confidence: 99%

“…For leukocytotropic species (A. bovis and A. phagocytophilum), buffy coat smears are preferred to regular whole blood preparations, as due to leukopenia very few infected leukocytes may be present. Representing a leukocyte-and plateletenriched fraction, buffy coat is also considered useful for detection of A. platys morulae within platelets (Eddlestone et al 2007). In any case, bacterial detection is best achieved if smears are prepared immediately after blood collection.…”

Section: Microscopymentioning

confidence: 99%

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