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  • Molecular identification of Ehrlichia in the blood and urine of horses in northern Iran
  • Shiva Seifi,1,* Mohsen Soltani kojori,2 Amir Tukmachi,3 Abdolghafar Ownagh,4 Peyman Khademi,5
    1. urmia university
    2. urmia university
    3. urmia university
    4. Urmia University
    5. urmia university


  • Introduction: The Anaplasmataceae family is responsible for the newly discovered zoonotic disease ehrlichiosis. Equine ehrlichiosis is indeed a seasonal disease of horses that was initially detected in 1969 by Gribble in horses in northern California. Ehrlichia is a genus of tick-borne bacterial diseases that infect people, domestic and wild animals, and are mainly made up of Gram-negative, obligate intracellular bacteria. Ehrlichia is a genus in the Rickettsiales order with six identified species: Ehrlichia canis, Ehrlichia chaffeensis, Ehrlichia ewingii, Ehrlichia muris, Ehrlichia ruminantium, and Ehrlichia minasensis. Ehrlichia equi is the main agent. The equine species, especially donkeys, are the natural hosts of E. equi. Any age of horse is vulnerable, however clinical symptoms are less severe in horses under the age of 2 to 3 years. Agents from the genera Neorickettsia (also known as N. risticii) and Anaplasma have mostly been linked to equine ehrlichiosis (i.e., A. phagocytophilum). Rhipicephalus microplus, Amblyomma hebraeum, Hyalomma marginatum, and Haemaphysalis have been found to parasitize horses among the tick species that potentially vector this bacterium, implying that infection by E. minasensis could further transfer to other hosts, such as equines. The most noticeable symptoms of acute granulocytic ehrlichiosis in both dogs and horses are high temperature and exhaustion, usually accompanied by inappetence. Furthermore, horses frequently suffer distal limb edema, ataxia, and are hesitant to move. particularly in comparison to serological approaches, the specialized identification of granulocytic Ehrlichia DNA in blood and urine utilizing PCR method is extremely sensitive and specific, and active infectious disease caused by this pathogen may be swiftly recognized and treated attributed to the ability to trace the parasite. The PCR test was performed four days after the illness began
  • Methods: In the summer of 2022, 400 horse samples (200 serum and 200 urine) were gathered at random in three distinct geographical districts of Mazandaran province. Six races were represented in the population examined. The Caspian horse was the most common, accompanied by Turkmen, Kurd and Dukhon, Karabagh, and Arabian horses. Mares (n=180) and stallions (n=220) were the gender distribution. The animals were categorized into three age groups: (less than 6) (170 individuals), (6-12) (140 people), and above 12 years old (80 people). Each horse had a 10 ml blood sample taken from the jugular vein and placed in dry tubes without EDTA. After centrifugation (10 minutes, 3000 g), the serum was recovered, and catheters were used to aseptically take urine samples from horses. The urine sample was then transferred into 10 ml collection tubes (Tarsons). The gathered samples were transported to the microbiology lab in sterile tubes that had been kept on ice. The samples' genomic DNA was extracted using a commercial DNA extraction kit (Favogen, Taiwan), and following extraction, the samples were kept at -20 °C. Nano Drop analyzed the DNA that was extracted in terms of both quality and quantity (Termo Scientific, USA). Additionally, 16s rRNA gene primers were employed for the first identification of Ehrlichia. The primer was created using Amplifx software (version 1.7.0) for the 16s rRNA gene's nesting stage. Using the chi square test and SPSS software, the acquired data were statistically evaluated (SPSS Inc., Chicago, IL). P 0.05 was regarded as a significant value
  • Results: Forty samples (10%) of the 400 collected blood and urine samples were positive for Ehrlichia after PCR amplification of a 357 bp fragment of the 16s rRNA gene. A total of 12 (6%) and 28 (14%) urine and blood samples were positive for Ehrlichia, respectively. The presence of Ehrlichia in the blood and urine of the test subjects was statistically significant. A statistical analysis was performed in this study regarding animal age, gender, and breed. According to the data based on age, gender, and race, the Caspian horse race has the greatest amount of contamination. This disparity may be attributable to the small number of samples collected from the Caspian horse race
  • Conclusion: In the northern part of Iran, ehrlichiosis should be regarded as a serious health risk, and tick and cattle infections should be continuously monitored. The prevalence of ticks and stray dogs close to the horse shelter in the region is likely one of the primary causes of Ehrlichia in the horses.
  • Keywords: Ehrlichia, Caspian horse, Mazandaran, 16s rRNA