Preliminary Detection of Rickettsiae Using PCR Targeting OmpA Gene Among Dogs and Horses in Cairo, Egypt

BACKGROUND: Rickettsioses are intracellular bacterial infectious diseases causing high morbidity and sometime high mortality with public health importance.Aim: The aim of present study was to detect rickettsiae in dogs and horses in Cairo, Egypt by using Polymerase Chain Reaction (PCR) targeting OmpA gene.Methods: A total number of 200 blood samples (100 from dogs and 100 from horses) were collected from Cairo province, Egypt. All blood samples were investigated by PCR using OmpA gene to detect the rickettsial infection. Furthermore, hematological examination for all blood samples was performed.Results: PCR detection of rickettsiae using OmpA gene amplification revealed that the infection rate was 18 % and 72 % in dogs and horses, respectively. Regarding hematological changes, hypochromic anemia, significant increase in neutrophils, lymphopenia and monocytopenia were recorded in rickettsiae positive dogs. Meanwhile, thrombocytopenia, leucopenia and monocytosis were recorded in rickettsiae positive horses.Conclusion: The detection of rickettsiae in dogs and horses indicated that dogs and horses play a critical role as sentinels in an epidemiological approach of rickettsiae in Cairo, Egypt.