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Microsporidial infections have been recognized as an increasingly important infection in immunocompromized patients, particularly those infected with HIV/AIDS. This study was designed to study immune responses associated with experimental Encephalitozoon intestinalis infection in immunecompetent rats.Thirty-four rats in 3 groups, A (Control), B (Intraperitoneal) and C (Oral) were given injections of 0.5 ml of 2 x 10(6) of purified spores of Encephalitotozoon intestinalis spores and were observed for serum specific IgG for 21 days using both Direct and Indirect ELISA.In indirect ELISA, specific lgG were detected on days 7, 14 and 21 for the group B rats and on day 21 for group C and in direct ELISA method, specific lgG were detected in-group B rats on days 7 and 21, for group C rats on day 21 only, while in the control rats, specific lgG were not detected. There was no significant difference between the direct and indirect methods (df=1, X(2), P0.05). E. intestinalis was observed in stool samples of rats in 1/12 (08.33%) on days 14 and 21 in group B and in 4/10 (33.33%), 3/10 (25.00%) and 2/10 (16.67%) on days 7, 14 and 21 respectively in group C. In-group, A which is the control rats, no microsporidia were observed on days 0, 7, 14 and 21.There were no changes in the T-lymphocyte counts of rats prior to and after inoculation with spores. Extensive lesions were observed along the intestinal walls especially on the middle and lower sections of group C rats only.

Cuticular lipids were extracted in hexane from the females of four strains of Anopheles stephensi and separated by capillary gas chromatography. When the chromatograms produced were quantified and compared by discriminant analysis, compositional variations in the hydrocarbons indicated that two of the strains, 'Russ' (originally isolated in the former (U.S.S.R.) and 'Iraq' (from Iraq), both of which were susceptible to DDT and malathion, could be confidently separated from 'Beech' from India and 'St Mal' from Pakistan, both of which were resistant to DDT and malathion. A high degree of hydrocarbon segregation between each of the four strains might be associated with geographical variation. It appears that there are significant and real differences in the hydrocarbons of these strains and these may be at least partially related to genetic alterations resulting from prior insecticide exposure. However, far more analysis is required if any relationship with prior exposure is to be confirmed.

(1997). Hydrocarbon variation/discrimination between two strains of Anopheles albimanus Wied from El Salvador. Annals of Tropical Medicine & Parasitology: Vol. 91, No. 5, pp. 493-497.

Cuticular lipids were removed from adult female .inophries stephensi Liston and the cuticular hydrocarbons present were separated and quantified by gas chromatography. Comparison was made between the hydracarbons of four .-la. stephensi strains: Russ, sensitive to DDT and malathion and originally isolated in the former U.S.S.R.; Beech, a DDT-resistant Indian strain with high sensitivity to Piasnrodilrm species; St 41a1, a strain from Pakistan shown to be resistant to malathion; and Iraq, a DDT-susceptible strain from Iraq. Discriminant Analysis indicated that the four groups were distinct And that, on Average, X”,, of the population could beseparated on the basis ofthe quantities ofsome ofthe cuticular hydrocarbons. The profiles ofBeech and Russ or Russ and St Ma1 could be separated in 98”,, ofthe cases. There was reduced segregation between the profiles of St Ma1 and Iraq, suggesting greater similarity in the hydrocarbons of these two strains. The usef‘uiness of-cuticular hydrocarbon in determining species relationships is discussed.

Examination of chromatograms of karyotyped larvae of Anopheles gambiae s.s. and Anopheles arabiensis has revealed that there are differences in the profile of their epicuticular hydrocarbons. A discriminant analysis of the quantitative hydrocarbon data has shown that the An. gambiae Mopti 2Rbc/bc karyotype from Mali could be separated from the Forest 2La/a karyotype from Liberia in80% of cases. Similar analysis permitted80% separation of individuals of two karyotypes of Anopheles arabiensis: 2Rab/ + from Burkina Faso, and 2Rb/b from Madagascar.

Cuticular hydrocarbons of larvae of individual strains of the Anopheles gambiae sensu stricto were investigated using gas liquid chromatography. Biomedical discriminant analysis involving multivariate statistics suggests that there was clear hydrocarbon difference between the Gambian(G3), the Nigerian (16CSS and, its malathion resistant substrain, REFMA) and the Tanzanian (KWA) strains. The high degree of segregation (95%) in hydrocarbons among the four strains investigated indicates that further analysis is needed to enable understanding of hydrocarbon variation in samples of An. gambiae especially from areas where these populations co-exist.