Identification of Echinococcus Granulosus Strains in Isolated Hydatid Cyst Specimens from Animals by PCR-RFLP Method in West Azerbaijan – Iran

Background: The aim of this study was DNA extraction from protosco­lecses of Echinococcus granulosus and identification of these strains in West-Azerbai­jan Province, north western Iran.Methods: Thirty one livestock isolates from sheep and cattle were collected from abattoirs of the province. To investigate the genetic variation of the isolates, after DNA extraction by Glass beads-phenol chloroform method; PCR-RLFP analysis of rDNA-ITS1 was performed using three different restric­tion enzymes of Taq 1, Rsa 1 and Alu 1.Result: Amplified PCR products for all isolates were 1000bp band which is expected band in sheep strains (G1-G3 complex). The results of RFLP analy­sis also were the same for all isolates. PCR-RFLP patterns restriction en­zymes were identical as follows, Rsa1 bands under UV showed two bands approximately 655bp and 345bp. Alu1 bands were as follows: two approx­imately 800bp and 200bp and Taq1 did not cut any region and bands were approximately 1000 bp in all samples.Conclusions: Based on PCR-RFLP patterns of ITS1 fragment produced with endonucleases enzyme digestion in animal isolates, it can be concluded that a single strain of E. granulosus (sheep strain or G1-G3 complex) is domi­nant genotype in this provinc

Intensity of <i>Plasmodium berghei</i> oocyst infection per midgut in different biological forms of <i>Anopheles stephensi</i>.

<p>All batches of mosquitoes were artificially fed on BALB/c blood with equalized parasitaemas. Each dot represents the number of oocysts in an individual midgut, and the graph shows pooled data from four experiments. The horizontal bars indicate median infection intensity. Asterisks denote significant differences at <i>p</i><0.05 between the different mosquito forms (Mann-Whitney non-parametric t-test). The pooled data exhibit significantly different variances. Additional analyses were performed (by Kruskal-Wallis 1-way ANOVA with Dunn's multiple comparisons post test) on log-transformed oocyst counts from infected midguts (ignoring uninfected midguts), and did not find significant differences between the mosquito types.</p

Prevalence of <i>Plasmodium berghei</i> oocysts in different biological forms of <i>Anopheles stephensi</i>.

<p>All batches of mosquitoes were artificially fed on BALB/c blood with equalized parasitaemas. The percentage of fed mosquitoes exhibiting oocyst formation in their midguts was then determined. Each bar represents the geometric mean of four experiments, +/− 95% confidence intervals (<i>n</i> = 4; each experiment included 17–24 fed mosquitoes per test group). There were no significant differences in oocyst prevalence between the forms of mosquito.</p

Prevalence of <i>Plasmodium berghei</i> sporozoites in different biological forms of <i>Anopheles stephensi</i>.

<p>All batches of mosquitoes were artificially fed on BALB/c blood with equalized parasitaemas. The percentage of fed mosquitoes with sporozoites formation in their salivary glands was then determined. Each bar represents the geometric mean of four experiments, +/−95% confidence intervals (<i>n</i> = 4; each experiment included 17–24 fed mosquitoes per test group). Asterisk denotes significance (P = 0.0286, non-parametric Mann-Whitney t-test).</p

Effects of anti-mosquito midgut antiserum on the prevalence of <i>P. berghei</i> oocysts and sporozoites in two populations of <i>A. stephensi</i>.

<p>Antiserum was raised against midgut antigens from the Beech type form <i>of A. stephensi</i> and then a mixture of antiserum and <i>P. berghei</i> were fed to both the Beech type form and to intermediate form mosquitoes. The bars represent the percentage of fed mosquitoes exhibiting (a) oocysts in their midguts, and (b) sporozoites in their salivary glands. The mean of three replicate experiments is presented, +/− SEM. Asterisks denote significance at <i>p</i><0.05 (calculated by the Mann-Whitney non-parametric t-test).</p

Comparative Susceptibility of Different Biological Forms of Anopheles stephensi to Plasmodium berghei ANKA Strain

BACKGROUND: There are varying degrees of compatibility between malaria parasite-mosquito species, and understanding this compatibility may be crucial for developing effective transmission-blocking vaccines. This study investigates the compatibility of different biological forms of a malaria vector, Anopheles stephensi, to Plasmodium berghei ANKA strain. METHODS: Several biologically different and allopatric forms of A. stephensi were studied. Three forms were isolated from different regions of southern Iran: the variety mysorensis, the intermediate form and the native type form, and an additional type form originated from India (Beech strain).The mosquitoes were experimentally infected with P. berghei to compare their susceptibility to parasitism. Anti-mosquito midgut antiserum was then raised in BALB/cs mice immunized against gut antigens from the most susceptible form of A. stephensi (Beech strain), and the efficacy of the antiserum was assessed in transmission-blocking assays conducted on the least susceptible mosquito biological form. RESULTS: The susceptibility of different biological forms of A. stephensi mosquito to P. berghei was specifically inter-type varied. The Beech strain and the intermediate form were both highly susceptible to infection, with higher oocyst and sporozoite infection rates than intermediate and mysorensis forms. The oocyst infection, and particularly sporozite infection, was lowest in the mysorensis strain. Antiserum raised against midgut proteins of the Indian Beech type form blocked infection in this mosquito population, but it was ineffective at blocking both oocyst and sporozoite development in the permissive but geographically distant intermediate form mosquitoes. This suggests that a strong degree of incompatibility exists between the mosquito strains in terms of midgut protein(s) acting as putative ookinete receptors. CONCLUSIONS: The incompatibility in the midgut protein profiles between two biological forms of A. stephensi demonstrates a well-differentiated population structure according to geographical origin. Therefore, the design of potential transmission-blocking strategies should incorporate a more thorough understanding of intra-species variations in host-parasite interactions