الفهرس 
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Abstract
Cephalopina titillator larvae (Diptera: Oestridae) are considered an important nasal myiasis-producing agent of camels that causing different economic losses. Diagnosis of this parasite is very difficult and such a myiasis is mostly underestimated in living animal. Therefore, our recent study attempts to elucidate the five different C. titillator larvae antigens; L3CE, L2CE, DTc, ESP and SGc in detection of anti-C. titillator antibodies in camel’s sera. Moreover, the role of antigens as modulators of the host immune response has been investigated to determine the most immunogenic antigen which may be used for serodiagnosis or protection of camels against C. titillator infestation. Additionally, the partial mitochondrial genes of C. titillator larvae were investigated as a novel study at the molecular level in order to enhance our knowledge about C. titillator genetic structure.
The obtained results revealed that apparent prevalence of C. titillator infestation among camels using ELISA differed according to the used antigen. The higher values 89.66% and 79.31% were recorded with L2CE and SGc antigens, respectively. However, low apparent prevalence percentages 53.45%, 46.55% and 13.22% were demonstrated with ESP, DTc and L3CE antigens, respectively.
The present study was considered the first preliminary investigation of ELISA assay parameters; sensitivity, specificity, positive predictive value and negative predictive value of the different C. titillator prepared antigens used in diagnosis of C. titillator infestation among camels. Concerning obtained results of L2CE and SGc antigens indicated that both induced the highest specificity and positive predictive value reported 100% for each however, the sensitivity and negative predictive value recorded (51.72% and 53.57%) and (6.66% and 13.33%), respectively. Moreover, DTc and ESP antigens showed 52.38%, 55.55%, 33.33% and 73.3% and 90.90%, 73.68%, 93.33% and 66.66% for specificity, sensitivity, positive predictive value and negative predictive value, respectively. However, L3CE antigen indicated the highest sensitivity and negative predictive value demonstrated 100% for each, the lowest positive predictive value recorded 26.66% and specificity reported 57.6%.
The obtained data of SDS-PAGE revealed that there was a noticed universality among protein bands and its molecular weights in each antigen prepared from C. titillator larvae. The SDS-PAGE demonstrated the presence of 3 common bands at molecular weights ranged 15-20 kDa, 24-26 kDa and 46-49 kDa among different C. titillator prepared antigens. Moreover, 3 the protein bands at molecular weights ranged 9-10 kDa, 30-32 kDa and 33-35 kDa were detected among different C. titillator antigens except ESP antigen. Furthermore, the 40-43 kDa protein bands were demonstrated among different C. titillator antigens except L2CE antigen. As well as the bands at molecular weights ranged 38-39 kDa, 50-53 kDa and 60-63 kDa were demonstrated between L3CE, L2CE and DTc, L3CE, L2CE and ESP and L3CE, L2CE and SGc antigens, respectively. However, the polypeptides at molecular weights ranged 55-58 kDa and 70-71 kDa were detected between L3CE and SGc antigens only. In addition to 4 bands noticed as specific bands at molecular weights 21, 37 and 44 and 88 kDa within ESP, L2CE and SGc antigens, respectively.
Concerning evaluation of C. titillator antigens, the present study was the first that using PIS and PNIS sera plus to rabbit anti-sera in western blot analysis of different C. titillator antigens. The present data revealed that PIS and specific hyperimmune sera of different antigens presented complex polypeptides array ranged between 45-48 kDa as a common band contained in different C. titillator larvae antigens with different immunogenic theme. The colorimetric reaction of SGc antigen demonstrated a noticeable intensely stained band rather than the other antigens which showed weakly stained bands at the same molecular weight when evaluated against PIS and PNIS sera. This result confirmed the result of high percentage of antibodies obtained in ELISA assay evaluating SGc antigen. This interpretation was strengthened that polypeptides in the salivary glands content had the capability to induce the host immune response due to its preferential relationship against this antigen. Moreover, ESP antigen presented somewhat similar image of SGc antigen where ESP antigen presented less marked bands as those demonstrated by SGc antigen when evaluated against PIS serum.
Although L2CE showed highest specificity and positive predictive value in ELISA assay parameters, the immunoblotting analyses revealed that L2CE was less immunogenic where it fairly recognized by PIS serum.
In spite of the faint immunogenic theme of L3CE antigen when tested against PIS serum via western blotting analysis, it showed the highest antigenicity where it presented the great number of polypeptides bands when evaluated against PIS and different prepared hyperimmune sera.
Concerning the immunogenic profile of DTc antigen when tested against PIS serum, these fairly stained bands were produced under constraints conditions of lowest serum dilution 1:50 and longer developing time 30 minutes in substrate buffer. On contrary, when this antigen evaluated against its specific hyperimmune serum, it presented an excellent immunogenic profile under highest serum dilution 1:800 and shorter developing time 10 minutes in substrate buffer.