Identification of a Cyclospora cayetanensis Oocyst Antigens and Their Validity in the Detection of Immunogenic Patterns

  • PDF / 1,170,896 Bytes
  • 12 Pages / 595.276 x 790.866 pts Page_size
  • 69 Downloads / 147 Views

DOWNLOAD

REPORT


ORIGINAL PAPER

Identification of a Cyclospora cayetanensis Oocyst Antigens and Their Validity in the Detection of Immunogenic Patterns of Cyclosporiasis Patients Eman M. Hussein1   · Eman K. El‑Gayar1 · Ola A. Ismail1 · Amira B. Mokhtar1 · Maha M. Al‑Abbassy1 Received: 17 April 2020 / Accepted: 22 September 2020 © Witold Stefański Institute of Parasitology, Polish Academy of Sciences 2020

Abstract Introduction  The diagnosis of cyclosporiasis is currently based on the microscopic detection of oocysts, which may provide invalid results. The availability of simple, objective immunological screening tests would facilitate epidemiological studies of cyclosporiasis. Therefore, the present study aimed to identify the antigens of Cyclospora cayetanensis oocysts and their validity in serodiagnosis. Methods  According to parasitological and molecular diagnoses, three study groups were specified. Group (G) I included 30 patients with cyclosporiasis, GII included 12 patients with other parasitic infections, and GIII included 16 healthy subjects. SDS-PAGE was used to analyse C. cayetanensis antigens, and the validity of western blotting and enzyme-linked immunosorbent assays (ELISAs) was then assessed amongst the sera of all study groups. Results The C. cayetanensis antigenic profile showed eight characteristic bands with molecular weights ranging from 14 to 175 kDa. Western blot analysis of sera revealed 93.3% (28/30 of GI) and 92.8% (26/28 of GII and III) sensitivity and specificity, respectively, dividing the patients in GI into four subgroups. The most frequent diagnostic bands (71.4% of GI sera) showed weights of 26–28 kDa, followed by 71 kDa (53.6%). ELISA sensitivity was 90% (27/30), and specificity was 78.6%. Validation showed perfect agreement between the PCR and western blot results, and ELISA presented substantial agreement with both the PCR and western blot results. Conclusions  Our findings suggest the existence of high immunogenic diversity in C. cayetanensis and indicate that the 26–28 kDa immunogenic groups may potentially be used as a diagnostic marker of cyclosporiasis. Due to the high validity of ELISA, it might be the test of choice for the routine serodiagnosis of cyclosporiasis. Keywords  C. cayetanensis · Oocysts · Antigens · SDS-PAGE · Western blotting · ELISA

Introduction Coccidian protozoa of the genus Cyclospora are obligate intracellular Apicomplexan parasites that infect a variety of hosts, amongst which Cyclospora cayetanensis is the only species infecting humans [26]. The prevalence rate of C. cayetanensis infection ranges from 4 to 41.6% amongst patients with gastroenteritis, whereas during epidemics, the rate ranges from 10.3 to 86% of diarrhoeal cases [5]. Cyclosporiasis has been identified as a leading cause * Eman M. Hussein [email protected] 1



Medical Parasitology Department, Faculty of Medicine, Suez Canal University, Ismailia 41522, Egypt

of significant morbidity in both immunocompetent and immunocompromised patients, resulting from the ingestion of sporulated oocysts in contami