Scanning electron microscopic study of trophozoite and cyst stages of naegleria fowleri

Whole trophozoites and cysts of axenically cultivated Naegleria fowleri were prepared for study of their surface morphology by scanning electron microscopy [SEM]. Trophozoites and cyst stages were studied from Chang's culture media. Some trophozoites were examined after animal inoculation and brain isolation to compare the changes in surface features. Photomicrographs of freeze-dried and critical point-dried organisms fixed with glutaraldehyde were presented along with views of both isolates of trophozoites to compare the surface features. SEM revealed the surface of trophozoites to be undulating, wrinkled and covered at irregular intervals by protruding vesicles. There were also surface extensions which were long and thin in brain isolates which may help in the contact and cytolysis of host cells at some distance from the trophozoite Some cysts appeared wrinkled while others smooth, and empty cysts were also seen with many pores on the surface

preliminary study on the prevalence of parasitic Infections in immunocompromised children

Parasitic infections might become life threatening in immuno-compromised children' The study assessed the parasites' prevalence in different groups of Immuno-compromised children. It was conducted on 120 children of whom 90 were inpatients in Tanta University Pediatric Hospital and were divided into 6 groups. GI: malignant diseases, GII: renal diseases, GIII: aggressive corticosteroid therapy, GIV: malnourished, GV: diabetic and GVI: miscellaneous. GVII comprised healthy children as control. Each child was subjected to history taking, clinical examination and examination of 3 stool samples by direct wet smear and a concentration technique. Coproculture and smear staining by a special stain, as well as examination of one blood sample for anti-Toxoplasma antibodies were done. The diagnostic efficacy of an immuno-chromatographic test for Giardial Cryptosporidiurn coproantigen was also assessed. The results revealed parasitic infections in 62.2% of the children in the test groups. Cryptosporidium was the most prevalent [33.3%]. Cryptosporidium and Microsporidia were significantly prevalent in GI, Giardia was significantly high in GII, and Strongyloides stercoralis was detected in GIII. Coproantigen detection test showed 100% sensitivity, 87.5% specificity and 95% accuracy for Giardia; and 13.3%, l00%, 35% for Cryptosporidium respectively

Seroprevalence study of Toxocara canis in selected Egyptian patients

This study was conducted in order to reveal the seroprevalence of T. canis infection in selected 150 Egyptian patients with presumptive clinical syndromes. They were children [128] with respiratory symptoms or pyrexia of unknown origin [PUO] and adults [22] with PUO. Anti-Toxocara antibodies [IgG] were detected in sera by ELISA. The results showed 6.2% positivity in children. The frequency increased in male gender, those in rural residence and in 6-12 years group versus 1-6 years, and 4% and 13.3% positivity in those with respiratory symptoms and PUO respectively. Adults positivity was 18%. So, male gender and residence in rural regions could be considered as risk factors for transmission of toxocariasis in children

Hypothalamic origin of reproductive failure in chronic experimental toxoplasmosis

Laboratory bred female mice were used to study the effect of chronic toxoplasmosis on reproductive performance. The animals were infected with small dose [3 x 103] tachyzoites of Toxoplasma parasites. The female mice were mixed with normal males for one week, then separated to monitor their reproductive performance one and two months post- infection [pi]. Mice bred one-month pi showed reproductive failure with one of twenty females delivered two sick newborns. The others did not complete pregnancy and fetal wastage occurred. Mice bred two months pi were infertile. Histopathological examination of the ovaries revealed impaired folliculogenesis and atropic degeneration. Coronal sections of cerebrum showed widespread vasculitis and focal disruption of the ependymal cells lining both lateral and third ventricles. The supraoptic and paraventricular hypothalamic nuclei were deformed and showed pyknotic neurons. Immunoperoxidase staining was used to detect IgG and IgM deposits in brain tissue. IgG deposits were found on the vicinity of Toxoplasma cysts and focally in the paraventricular zone. So, the reproductive failure of infected mice was due to hypogonadotrophic hypogonadism secondary to hypothalamic dysfunction as a result of chronic toxoplasmosis

Morphometric and histopathological studies of bile duct in experimental schistosomiasis

This study was done to investigate the effect of Schistosoma mansoni infection on the morphology of bile ducts and liver tissue in experimental animals. Thirty-six golden hamsters were infected with 300 cercaria of Schistosoma mansoni. Six animals were sacrificed every four weeks post infection till the 16th week. The livers were dissected and the parts of common bile ducts were cut and were examined microscopically. Paraffin sections were prepared and stained with hematoxylin and eosine and with Van Gieson stains. The wall thickness of bile ducts were compared between infected and non infected. Extensive dilatation and thickening of bile duct walls were found in comparison with noninfected liver sections. In infected animals, there was four times increase in the thickness of duct wall in late weeks of infection. Focal necrotic lesions, and lymphocytic infiltration were scattered throughout liver parenchyma of infected animals. It has been suggested that Schistosoma mansoni which is a common parasite in Egypt release large amounts of proline and induces collagen deposition in bile ducts leading to marked periductal fibrosis

Experimental trichinosis in alloxan induced diabetes in mice

The course of Trichinella spiralis infection was studied in Alloxan induced diabetes in mice. The number of Trichinella larvae in muscles of infected animals was estimated by digestion of whole carcases and compared with control non diabetic group. Histopathological study of infected muscles was also done. It was found that diabetic mice developed very heavy muscle parasitism and their larval count was high compared with non diabetic animals. Besides, there was heavy inflammatory cellular reaction around poorly encapsulated larvae. Mortality rate was 100% by day 45 in diabetic mice while control animals survived during the period of observation which was 3 months. These data indicated that hyperglycaemia significantly increased parasitisaemia and mortality in mice infected with T. spiralis

Isolation of soil amoebae from the nasal mucosa of children in Tanta - Egypt

Forty children attending the outpatient clinic, Tanta University Hospitals were examined by nasal swabing in order to discover the healthy free-living amoebae carriers. The swabs were cultured on non-nutrient agar with active E-coli and incubated at 37°C and 45°C. Two species of free-living amoebae were identified: Hartmannella agricola and Acanthamoeba polyphaga. Pathogenicity of these amoebae was tested by intranasal instillation in mice. During the observation period of two months, 20% of mice died within 21 days post inoculation. The possible role of these amoebae in the nasal cavity and the way of contamination are discussed

Experimental amoebic meningoencephalitis: light microscopic and ultrastructure studies in mice

Heamorrhagic meningoencephalitis was found in the animals which died in 5-7 days post infection. The olfactory lobes and the base of the frontal lobes were congested and full of pus. Gray and white matter were both affected and were invaded with macrophages and leukocytes. Trophozoites were located between the neurons and adjacent to blood vessels. Ultrastructural study showed some amoebae with evidence of vigorous motility and feeding abilities. Erythrocytes and portions of myelin were seen within amoebae. The whole picture of the disease was similar to that observed in man which makes the mice an excellent model for further understanding of the disease

Incidence, clinical picture and treatment of giardiasis in childhood

A random sample of 300 children attending the inpatient clinics of Banha and Tanta Universities Hospitals were examined for Giardia lamblia infection. 71 were positive for Giardia giving an incidence of 23.6%.Mixed infection with other parasites were found in 12 cases. The clinical picture was variable 22.5% were asymptomatic. Foul smelling stools, anorexia, abdominal pain and diarrhea were the frequent symptoms of infection specially in the pre-school aged children. Anemia and eosinophilia were also present. The children were given metronidazole as treatment which proved effective in 80.2% of them