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Iranian journal of veterinary research2025; 26(2); 145-151; doi: 10.22099/ijvr.2025.51028.7553

Molecular detection and genotyping of Theileria equi infection within the equine population in Giza, Egypt, using real-time PCR as compared with conventional detection methods.

Abstract: Equine piroplasmosis represents one of the main and serious health problems affecting the equines industry globally, caused by a tick-borne protozoa called and . This study aimed to identify and genotype within the equine population from Giza Governorate, Egypt, by comparing the obtained results using the available diagnostic methods. Unassigned: We collected 116 apparently healthy horses from the study area during the first half of 2019 to identify using real-time PCR (qPCR), targeting the gene. The results were compared with those from microscopic examination of Giemsa-stained blood smears and conventional PCR. Genotyping of the obtained sequences was also conducted to explore the genetic diversity of the detected strains. Unassigned: Through sequencing and phylogenetic analysis, our samples were grouped into clusters corresponding to genotype A and genotype E. Our results demonstrated that the qPCR had the highest sensitivity (100%) followed by conventional PCR (68%) while microscopic examination had the lowest sensitivity (38%). Furthermore, the negative predictive value (NPV) of qPCR was the highest (100%) compared with conventional PCR and microscopical examination (80.49% and 68.04%, respectively) which revealed that negative cases detected by qPCR were certainly correct compared with the other two diagnostic assays. Unassigned: It is highly recommended to incorporate PCR diagnostic assays alongside microscopic examination to evaluate the epidemiological status of equine piroplasmosis. Also, our study demonstrated that genotype A and genotype E are circulating among Egyptian horses.
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Publication Date: 2025-10-31 PubMed ID: 41170307PubMed Central: PMC12571432DOI: 10.22099/ijvr.2025.51028.7553Google Scholar: Lookup
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Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

Overview

  • This study evaluated the presence and genetic diversity of Theileria equi, a parasite causing equine piroplasmosis, in horses from Giza, Egypt.
  • The research compared the effectiveness of real-time PCR (qPCR), conventional PCR, and microscopic examination for detecting the infection and performed genotyping to understand parasite diversity.

Background

  • Equine piroplasmosis is a tick-borne disease affecting horses worldwide, primarily caused by the protozoa Theileria equi and Babesia caballi.
  • This disease poses significant health problems for equines and economic challenges to the equine industry.
  • Accurate detection and understanding of parasite genotypes are crucial for effective disease management and control.

Study Objectives

  • To detect Theileria equi infection among apparently healthy horses in Giza Governorate, Egypt.
  • To compare the diagnostic performance of three detection methods: qPCR, conventional PCR, and microscopic examination of blood smears.
  • To genotype the identified T. equi strains to investigate their genetic diversity and epidemiological distribution.

Methods

  • 116 horses, apparently healthy, were sampled from Giza during the first half of 2019.
  • Real-time PCR (qPCR) targeting the ema-1 gene of T. equi was performed for sensitive detection of the parasite.
  • Microscopic examination involved analyzing Giemsa-stained blood smears for parasite visualization.
  • Conventional PCR assays were also conducted to compare results with qPCR and microscopy.
  • Positive samples underwent genetic sequencing and phylogenetic analysis to identify genotypes and assess their diversity.

Results

  • Theileria equi infection was detected in the horses with variable sensitivity depending on the method used:
    • qPCR detected 100% of cases, showing the highest sensitivity.
    • Conventional PCR detected 68% of cases.
    • Microscopic examination detected only 38% of cases, indicating lower sensitivity.
  • Negative predictive value (NPV) was highest for qPCR (100%), indicating that negative test results with qPCR were reliable.
  • Conventional PCR showed NPV of 80.49%, and microscopy had 68.04%, both less reliable in ruling out infection than qPCR.
  • Phylogenetic analysis grouped the detected T. equi sequences into genotype A and genotype E clusters, confirming genetic diversity within the Egyptian equine population.

Conclusions and Recommendations

  • Real-time PCR demonstrated superior sensitivity and accuracy for detecting T. equi infection compared to conventional PCR and microscopy.
  • Microscopic examination alone is insufficient due to low sensitivity and might miss many infected cases.
  • The study recommends integrating PCR-based diagnostic techniques with microscopic methods to effectively screen and monitor equine piroplasmosis epidemiology.
  • The discovery of genotype A and E circulating among Giza horses highlights the importance of genotype monitoring for understanding transmission dynamics and potentially guiding targeted control strategies.

Significance

  • This work provides valuable epidemiological data on the prevalence and genetic diversity of T. equi in Egypt.
  • It underscores the importance of molecular diagnostics in veterinary parasitology for improved disease control.
  • Supports the use of qPCR as the preferred diagnostic tool for future surveillance and research on equine piroplasmosis.

Cite This Article

APA
Soliman AM, Elhawary NM, Helmy NM, El-Seify MA, Amer MM, Mohamed S, Memon FU, Rashid MHO, Gadelhaq SM. (2025). Molecular detection and genotyping of Theileria equi infection within the equine population in Giza, Egypt, using real-time PCR as compared with conventional detection methods. Iran J Vet Res, 26(2), 145-151. https://doi.org/10.22099/ijvr.2025.51028.7553

Publication

Iranian journal of veterinary research
ISSN: 1728-1997
NlmUniqueID: 101660030
Country: Iran
Language: English
Volume: 26
Issue: 2
Pages: 145-151

Researcher Affiliations

Soliman, A M
  • Biotechnology Department, Animal Health Research Institute, Agricultural Research Center, Dokki 12618, Giza, Egypt.
Elhawary, N M
  • arasitology Department, Faculty of Veterinary Medicine, Kafrelsheikh University, 33516 Kafrelsheikh, Egypt.
Helmy, N M
  • Biotechnology Department, Animal Health Research Institute, Agricultural Research Center, Dokki 12618, Giza, Egypt.
El-Seify, M A
  • arasitology Department, Faculty of Veterinary Medicine, Kafrelsheikh University, 33516 Kafrelsheikh, Egypt.
Amer, M M
  • Biotechnology Department, Animal Health Research Institute, Agricultural Research Center, Dokki 12618, Giza, Egypt.
Mohamed, S
  • Graduated from Faculty of Medicine, Mansoura University, 35516 Mansoura, Egypt.
Memon, F U
  • Department of Poultry Husbandry, Faculty of Animal Husbandry and Veterinary Sciences, Sindh Agriculture University, Tando Jam 70060, Pakistan.
Rashid, M H O
  • Ph.D. Student in Infectious Diseases, Transboundary Animal Diseases Center, Joint Faculty of Veterinary Medicine, Kagoshima University, Korimoto, Kagoshima 8900065, Japan.
Gadelhaq, S M
  • Parasitology Department, Faculty of Veterinary Medicine, Minia University, Minya, Egypt.

Conflict of Interest Statement

The authors declare that they have no competing interests.

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