CL users were more exposed to AK and should gain enough health education regarding proper lens hygiene and dangers of tap water exposure.

SUMMARYSteam distillation of essential oils of aerial parts of Thymus capitatus and Marrubium vulgare L. collected at North cost of Egypt yielded 0.5% and 0.2%, respectively. Results of Gas chromatography-mass spectrometry analyses of the two samples identified 96.27% and 90.19% of the total oil composition for T. capitatus and M. vulgare, respectively. The two oil samples appeared dominated by the oxygenated constituents (88.22% for T. capitatus and 57.50% for M. vulgare), composed of phenols, mainly carvacrol (32.98%) and thymol (32.82%) in essential oil of T. capitatus, and thymol (34.55%) in essential oil of M. vulgare. It was evaluated the molluscicidal activity of T. capitatus and M. vulgare essential oils on adult and eggs of Biomphalaria alexandrina as well as their mosquitocidal activity on Culex pipiens. The LC 50 and LC 90 of T. capitatus essential oil against adult snails was 200 and 400 ppm/3hrs, respectively, while for M. vulgare it was 50 and 100 ppm/3hrs, respectively. Moreover, M. vulgare showed LC 100 ovicidal activity at 200 ppm/24 hrs while T. capitatus oil showed no ovicidal activity. It was verified mosquitocidal activity, with LC 50 and LC 90 of 100 and 200 ppm/12hrs respectively for larvae, and 200 and 400 ppm/12hrs respectively for pupae of C. pipiens.

No abstract

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 present study spotted some light on human fascioliasis in Kafr El-Sheikh Governorate in the west of the Nile Delta in Egypt, its species, its intermediate host (IMH) snail and tried to answer previous questions about development of Fasciola (F.) species in new snail hosts other than that known for animal fascioliasis in Egypt. The study recorded a percentage of infection by Fasciola eggs reached up to 6.02% in 1810 randomly collected human stool samples from 6 climatically selected sites in this governorate using fluke-finder technique. The incidence was high in Sedi Salem and Motobus than in the other study sites. Micrometry measuring of 100 eggs from each locality showed that egg size cannot be used as a main criterion in differentiation between F. hepatica and gigantica. Wide range of egg size varied between 130-162.5 µ X 75-87.5 µ with a mean length and width of 144.24 ± 11.33 µ X 80± 6.55µ, was recorded. Upon dissection of 1972 Lymnaea (L.) cailliaudi, 268 L. alexandrina, 502 Bulinus species, 11316 Biomphalaria alexandrina, 1398 Cleopatra species, 8520 Physa acuta, 420 Melania tuberculata, 2132 Vivipara (Bellamya) unicolar, 144 Neritina nilotica and 1570 Planorbis philippi, Fasciola parthenitae were not detected in snails other than L. cailliaudi (the known IMH of Fasciola in Egypt). The results proved that there is no accommodation has occurred in any of the surrounding snails to transmit Fasciola to man. The present study proved that human fascioliasis in the study sites was due to Fasciola gigantica not F. hepatica. This appeared in its tendency to develop in L. cailliaudi not in other tested snails with successive radial generations as that described previously for F. gigantica. Moreover, early mature flukes extracted from laboratory infected rabbits by the produced encysted metacercariae had the characteristic features described previously for F. gigantica.

No abstract

Egyptian native plants continue to provide a wealth of potential sources for biologically active agents that may have a promising role in the production of safe, biodegradable eco-friendly and natural molluscicidal and insecticidal agents.

No abstract