Diagnostic importance of female external genital structure of phlebotomine sand flies (Diptera: Psychodidae) as observed by scanning electron microscopy

Morphological description of sand flies has remained a neglected area. The different organs used in taxonomy have not yet been described adequately with the scanning electron microscopy (SEM). We have examined the external genital structures of females of three Old World phlebotomine sand flies under SEM and recorded the morphological variations of the organs. We have found the female external genital strutures of the three species varied considerably in morphology. The importance of the female external genital structures in sand fly identification is indicated.

Blood meal analysis of Phlebotomus argentipes in eight districts of West Bengal.

Eight districts of West Bengal (India) were surveyed for the biting habit of Phlebotomus argentipes using agar gel diffusion method. Blood meal indices were found different in the two biotopes, human dwellings and cowsheds. A total of 395 blood meals were analyzed. The blood meal indices in the human dwellings were human 68.8 per cent, cow 38.9 per cent, both human and cow 10.2 per cent, others 2.5 per cent and in the cowsheds: human 19.7 per cent, cow 91.6 per cent, human and cow 13.9 per cent and others 2.5 per cent. These indicated that P. argentipes did not show preference to any blood meal.

Characterization of potentially pathogenic free-living amoebae in sewage samples of Calcutta, India

1. It is widely accepted that foul or polluted environments are the principal sources of potentially pathogenic species of free-living amoebae. The present paper is the first report of occurrence of potentially pathogenic free-living amoebae in sewage sample of Calcutta, India. 2. We describe the occurrence, isolation, specific identification and comaprative mouse pathogenicity test of two pathogenic amoebae, viz., Naegleria fowleri (N. aerobia) carter, 1970, causing human meningoencephalitis and Acanthamoeba castellanii Douglas, 1930, causing granulomatous amoebic encephalitis, and one non-pathogenic amoeba, viz., A astronyxis Ray and Hayes, 1959, in sewage samples of Calcuta, India. 3. The existence of both pathogenic and non-pathogenic amoebae living side by side is of considerable epidemiological relevance

Excreted factors and membrane-associated carbohydrates of Indian leishmaniae.

Antigenic identity between the cell surface carbohydrate ligands and their excreted factor (EF) in all forms of Indian leishmaniasis were assessed by 11 carbohydrate-specific lectins. Our results demonstrated that 3 lectins, viz. PNA, SBA and WFA showed unique selectivity towards skin-dwelling parasites. The EFs of visceral leishmaniasis (VL), post-kala-azar dermal leishmaniasis (PKDL) and cutaneous leishmaniasis (CL) formed band against ConA at 1000, and 500 micrograms/ml concentration, respectively. RCA-120 at 3 mg/ml concentration was positive to both Leishmania tropica and L. major, whereas SBA was specific to L. tropica, L. major and PKDL strains at the same concentration. Antisera directed against the EFs (EF-As) induced agglutination to homologous promastigotes suspension. Cross-reactivity of agglutination was observed in different strains but highest was found among PKDL and CL strains. Although PKDL cases are normally found in patients with the history of visceral leishmaniasis (kala-azar), surprisingly in this study, the surface saccharides of PKDL strains had close affinity to CL type instead of VL.