الفهرس 
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Abstract
The present study explored the impact of anti-sandfly saliva antibodies formed in a sensitized vertebrate hosts on the biological aspects of Phlebotomus papatasi.
A laboratory colony of the sandfly P. papatasi was established based on the sandfly sampling collection from El-Agamy-Alexandria, in May 2014. Sandfly colonies were maintained in the walk-in insectary at the Research and Training Centre on Vectors of Diseases (RTC) of Ain Shams University. Also, a total of twelve laboratory-reared male golden hamsters (100-120 gm) were obtained from Nile Pharmaceutical Company by adapted car. Hamsters were housed in an animal room, at (RTC) according to the Ethics committee at the Faculty of science, Ain Shams University, Egypt Institutional Animal Care and Use Committee (I A C U C).
Hamsters were divided into four groups each of three (group A (GA), group B (GB), group C (GC), and group D (GD)). All hamsters were intra-peritoneal anesthetized to allow group of 25 experimental female
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P. papatasi (3-day old) to feed on the four groups of hamsters for the experiments of the study.
1. Biological studies:
1.1. Effect of repeated sandfly bites on hamsters on their attraction to hamster’s blood:
In order to test the ability of sandflies to feed on same hamster after repeating bites, 25 P. papatasi adult females were allowed to feed on each hamster in each of three groups of experiment. Results revealed that the feeding response of completely-fed flies was decreased significantly from 98.7% at the 1st week to 6.7% at the 18th week. However, a significant increase was observed in the feeding response of half-fed flies ranged from 1.3% at the 1st week to 18.7% at the 18th week. Also, a significant increase was recorded in the feeding response of non-fed flies ranged from 0% at the 1st week to 74.6% at the 18th week. The obtained results indicated that the repeated bits of flies on the same hamster causes significant changes in feeding response of flies.
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1.2. Effect of immunization of hamsters by bites on sandflies fecundity:
The total number of eggs laid by experimental female groups was compared to those in control groups at week 3, 6, 9, 12, 15 and 18.
Females fed on the control animals (non-exposed for biting) laid the highest number of eggs while females fed on the 18th weeks exposed hamster (immunized) laid the lowest number of eggs. The results revealed a significant decrease in the number of egg laying by females P. papatasi fed on immunized hamster by bites compared to control one (P > 0.00).
1.3. Effect of feeding on immunized host on sandflies mortality:
The effect of immunization by bites on sandflies survival was determined by recording the dead adult females post feeding on the hamsters at days-1, 3, 5, 7, and 9 through weeks 9, and 18 post feeding and comparing with control ones. It was observed that more than 90% of 70 (number of tested females) females fed on hamster was survived until day-9 post feeding till
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week 18 of experiment. Similar mortality rates were recorded at day-5 in the groups of experiment. Comparable rates of dead sandflies among three groups during days of recording mortality were shown (i.e. day-1, 4.3, 7.9, and 12.9% mortality among control, week-9, and week-18, respectively). In contrast, remarkable decrease in mortality rate was observed at day-9 post feeding in three groups especially in those fed on hamster till week 18.
2. Immunological and Biochemical studies:
2.1. Electrophoretic protein patterns of sandflies’s salivary gland homogenate (SGH):
A total of 80 pairs of salivary glands from females P. papatasi dissected. The SDS protein patterns of sandfly’s SGH revealed different numbers of protein bands according to their molecular weights in both unfed and blood fed ones., The total number of protein bands in SGH of non-fed sandflies samples were 20 bands appeared with percentage amount values ranged between 2.39 – 7.27 and molecular weights ranged between 5.24 – 97.52kDa. However, protein of salivary gland homogenates in blood-fed sandflies were analyzed to 14 bands with percentage amount values
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ranged between 2.72-6.45 and molecular weights ranged between 9.12-77.5kDa. There are only three protein bands had similar electrophoretic fractions with molecular weights ranged between 14.55, and 70.00 kDa which represented to the conserved proteins exist in both SGH of blood-fed, and non-fed ones.
2.2. Serum protein patterns in non-immunized and immunized hamsters:
The SDS protein patterns of hamster serum revealed different numbers of protein bands according to their molecular weights. In the serum of normal hamster, the total number of protein bands were 14 with percentage amount values ranged between 2.46 – 14.90 and molecular weights ranged between 10.12 – 96.67kDa. However, in immunized hamster, the collected sera were analyzed into 17 and 16 bands along week9, and 18, respectively with percentage amount values, and molecular weight ranged between 2.86-9.97 and 1.92-8.52 from those collected at week 9, and (15.21–96.67) and (12.21-96.67) kDa at week 18.
As compared with control, almost all protein fractions in the immunized group, either at week 9, or
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18, had more proteins bands than those found in the non-immunized group.
2.3. Salivary gland antigen versus Serum antibody:
There were six common bands with respective M.wts 69, 60, 47, 34, 20, and 12 kDa were detected in both the antigen protein of SGH of blood-fed female sandflies and the antibodies of 18 weeks-exposed hamsters (Fig. 25). Detection of these common bands confirmed the production of antibodies in hamster sera resulting from repeated exposure to sandflies bites.
In conclusion, the effect of anti-sandfly saliva antibodies on the biological aspects of P. papatasi needs further investigations to uncover how relevant target macromolecules function. These investigations could contribute to defining the salivary gland proteins that might be useful for vaccination against leishmaniasis.
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