Laboratory findings in cows after experimental infection with Ehrlichia phagocytophila

Abstract

The goal of this study was to assess various hematological variables in 10 cows after experimental infection with Ehrlichia phagocytophila. Blood samples were collected at regular intervals for examination of leukocytes for Ehrlichia organisms and for determination of hematological and biochemical variables. In addition, PCR amplification was performed throughout the disease period on blood and milk samples for the detection of E. phagocytophila organisms. The time of seroconversion and the duration of serum titers indicating positivity were determined by indirect immunofluorescence. For all cows, E. phagocytophila organisms were first detected microscopically in leukocytes 5 to 8 days postinfection and could be demonstrated for a period of 6 to 14 days. For all cows, the appearance of E. phagocytophila organisms in leukocytes coincided with transient erythropenia, leukopenia, and thrombocytopenia and a decrease in hematocrit and hemoglobin concentration. For five lactating cows, E. phagocytophila organisms were identified in leukocytes of milk samples during the acute phase of the disease, which, we believe, has not previously been reported. E. phagocytophila DNA was detected in blood samples by nested PCR from 1 to 2 days before to 2 to 12 days after the organisms were identified microscopically. In milk samples, E. phagocytophila DNA was detected for an average of 11 days.

Granulocytic ehrlichiosis in two dogs in Switzerland

“…Over the last several years, the diagnosis of ehrlichiosis has been improved with the introduction of PCR (1,3,5). The two primer pairs used in this study allowed us to extend the diagnostic spectrum to the entire E. phagocytophila group (10). As expected, DNA fragments of equal size were amplified from samples from both dogs and from the E. phagocytophila and E. equi isolates.…”

“…The procedures used for nested PCR have been previously described (10). Products from nested PCR were resolved on 1.2% agarose gels, stained with ethidium bromide, and examined under UV illumination.…”

High Prevalence ofAnaplasmaspp. in Small Ruminants in Morocco

“…Alternatively, bacteraemia in A. phagocytophilum infection may be of shorter duration than for A. marginale and A. ovis . In fact, PCR and microscopy give peak sensitivity in the acute stage of disease, between the 4th and 22nd day post‐infection (PI) for PCR (Pusterla et al., ) and between 2nd and 14th day PI for microscopy (Schotthoefer et al., ). It is also possible that the sample size was too small to detect a disease with such a low prevalence, even though there have been up to now no reports of A. phagocytophilum in Morocco.…”

Detection of Ehrlichia phagocytophila DNA in Ixodes ricinus Ticks from Areas in Switzerland Where Tick-Borne Fever Is Endemic

“…Nested PCR. The methods used for nested PCR for identification of the members of the E. phagocytophila group have been described previously (2,13). The sensitivity of the PCR method was assessed by dilution of an Escherichia coli-cloned 16S rRNA gene segment from E. phagocytophila of approximately 1,200 bp.…”