The diagnosis of patients with cystic echinococcosis (CE) by means of serology has a limited support in clinical practice due to cross-reactivity with other helminthes leading to overestimation of the parasite's true prevalence. A wealth of reports on the diagnostic performance of antigen B (AgB) has been produced. This study was designed to comparatively assess the diagnostic efficacy of crude sheep hydatid cyst fluid (HCF), AgB and its subunit (12 KDa) to detect IgG or IgG4 antibodies in CE patients' sera using enzyme-linked immunosorbent assay (ELISA).The best diagnostic performance was obtained with anti-HCF IgG ELISA which gave 92.4% sensitivity and 92.6% specificity. Despite the low sensitivity of anti AgB IgG ELISA (84%), it gave the best specificity (94.4%) with less cross-reaction with sera of subjects infected with other parasites. In conclusion, it is recommended to use anti-HCF IgG ELISA for initial screening in large seroprevalence studies. Further analysis of positive serum samples with anti AgB IgG ELISA would allow the confirmation of true positives. Specific IgG4 ELISA may represent a complementary assay, useful as secondary confirmatory tests for patients with suspected CE and negative for total IgG ELISA.

Acanthamoebae are the most common opportunistic amphizoic protozoa that cause life-threatening granulomatous amoebic encephalitis in immunocompromised individuals and sight-threatening amoebic keratitis (AK) in contact lens wearers. The present work aimed to determine the presence of Acanthamoeba isolates in different environmental sources: water, soil, and dust in Cairo, Egypt and to characterize the pathogenic potential of the isolated Acanthamoeba using physiological and biochemical assays as well as determination of the genotypes in an attempt to correlate pathogenicity with certain genotypes. The study included the collection of 22 corneal scrapings from patients complaining of symptoms and signs indicative of acanthamoeba keratitis (AK) and 75 environmental samples followed by cultivation on non-nutrient agar plates preseeded with E. coli. Positive samples for Acanthamoeba were subjected to osmo- and thermo-tolerance assays and zymography analysis. Potentially pathogenic isolates were subjected to PCR amplification using genus-specific primer pair. Isolates were classified at the genotype level based on the sequence analysis of Acanthamoeba 18S rRNA gene (diagnostic fragment 3). The total detection rate for Acanthamoeba in environmental samples was 33.3 %, 31.4 % in water, 40 % in soil, and 20 % in dust samples. Three and two Acanthamoeba isolates from water and soil sources, respectively, had the potential for pathogenicity as they exhibited full range of pathogenic traits. Other 12 isolates were designated as weak potential pathogens. Only ten of the environmental isolates were positive in PCR and were classified by genotype analysis into T4 genotype (70 %), T3 (10 %) and T5 (20 %). Potential pathogens belonged to genotypes T4 (from water) and T5 (from soil) while weak potential pathogens belonged to genotypes T3 (from water) and T4 (from water and soil). Additionally, T7 genotype was isolated from keratitis patients. There is a considerable variation in the response of Acanthamoeba members of the same genotype to pathogenicity indicator assays making correlation of pathogenicity with certain genotypes difficult. Presence of potentially pathogenic Acanthamoeba isolates in habitats related directly to human populations represent a risk for human health. Isolation of Acanthamoeba genotype T7 from AK cases, which is commonly considered as nonpathogenic, might draw the attention to other Acanthamoeba genotypes considered as non pathogenic and reevaluate their role in production of human infections. To our knowledge, this is the first study on the presence and distribution of Acanthamoeba genotypes in the environment, Cairo, Egypt.

The aim of the present work was to apply and evaluate a dipstick assay for the serodiagnosis of human hydatidosis as well as human and experimental trichinosis using camel hydatid cyst fluid (HCF) and Trichinella spiralis muscle larval (TSML) antigens, respectively, and compare this to enzyme-linked immunoelectrotransfer blot (EITB) and Falcon assay screening test-enzyme-linked immunosorbent assay (FAST-ELISA). Sera samples were collected from patients with confirmed hydatidosis and trichinosis and with other parasitic diseases as well as from normal healthy individuals. Also, sera samples were collected from mice experimentally infected with T. spiralis which were sacrificed at different time points post-infection (PI). HCF and TSML antigens were used in EITB after separation and characterization of their antigenic components using 5-22.5% sodium dodecyl sulphate-polyacrylamide gel electrophoresis under non-reducing condition. For the diagnosis of hydatidosis, the sensitivity, specificity and diagnostic accuracy of the dipstick assay and EITB were 100, 91.4 and 95.1% while those of FAST-ELISA were 96.2, 100 and 98.4%, respectively. For the diagnosis of human trichinosis, the sensitivity, specificity and diagnostic accuracy of the dipstick assay and EITB were 100% while those of FAST-ELISA were 85.7%. FAST-ELISA proved to be more sensitive in the early diagnosis of experimental T. spiralis infection (100% sensitivity from the second week PI) than the dipstick and EITB (100% sensitivity from the third week PI). All tests retained their sensitivity till the 12th week PI. Since the dipstick assay is extremely easy to perform with a visually interpreted result within 15 min, in addition to being both sensitive and specific, the test could be an acceptable alternative for use in clinical laboratories lacking specialized equipment and the technological expertise needed for EITB and FAST-ELISA.

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Genetic polymorphisms of encoding antigen B2 gene (AgB2) in Echinococcus granulosus were studied using PCR-RFLP and DNA sequencing among 20 Egyptian isolates. Five isolates from different host origins (humans, camels, pigs, and sheep) were collected and used. All examined isolates of each host group gave very similar patterns of PCR-RFLP after restriction enzyme digestion with AluI, with the gene size of approximately 140 bp and 240 bp for sheep and human isolates, and approximately 150 bp and 250 bp for pig and camel isolates. No digestion pattern was obtained after incubation of all studied isolates with EcoRI. These results reveal high intra-group homogeneity. DNA sequence analysis highlighted that human infecting strain showed 100% identity with respect to sheep infecting isolate, 96% and 99% with pig and camel infecting isolates, respectively.

The aim of the present work was to design praziquantel (PZQ) loaded chitosan nanoparticles (PZQ-Cs) to improve the oral bioavailability and overcome the drawbacks of conventional PZQ therapy. The synthesized chitosan nanoparticles (CsNPs) were physico-chemically characterized by TEM and dynamic light scattering (DLS) with the calculation of the encapsulation efficiency (EE). PZQ was loaded into CsNPs in three different doses; reduced dose (250 mg/kg), high dose (500 mg/kg) and fully effective dose (1000 mg/ kg). Infected treated groups received either oral PZQ-Cs or oral PZQ alone 42 days post-infection and were sacrificed 2 weeks post-treatment. The current study revealed that PZQ-Cs induced a significant anti-schistosomal effect, compared to the infected non-treated control. However, on comparison with conventional PZQ treatment at the corresponding doses, oral PZQ-Cs showed a lower anti-schistosomal potential as reflected by the total worm burden, tissue ova count and oogram pattern. PZQ-Cs was significantly effective in attenuating the oxidative insult associated with S. mansoni infection, compared to the infected non-treated and PZQ treated groups. Genotoxicity assessment proved the safety of CsNPs, as they did not induce a significant DNA fragmentation in non-infected mice treated with blank CsNPs. The present work highlights CsNPs as safe, effective anti-inflammatory and antioxidant agents that could find a clinical use in the treatment of schistosomiasis induced oxidative stress and hepatic dysfunction. Further studies are recommended, however, to investigate how PZQ-Cs could be further modified to increase its anti-schistosomal potential.