A modification of Diamond's medium for the axenic culture of Entamoeba histolytica.

The use of casein hydrolysate in Diamond's axenic culture medium TPS-1 in replacement of trypticase allowed good growth of the trophozoites of Entamoeba histolytica. This modified medium also supported growth of trophozoites preserved for 16 months in liquid nitrogen. Considerable labour and cost of serum can be saved by using 5% instead of 10% bovine serum in combination with this modified medium.

Use of monoclonal antibodies for the differential detection of Trypanosoma cruzi and T. rangeli in epidemiological studies and xenodiagnosis.

T. cruzi and T. rangeli have the same insect and mammalian hosts, including man, and in addition share approximately half the antigenic determinants recognised by the humoral response. Thus serodiagnosis of T. cruzi infection in areas where T. rangeli is endemic may include an unknown rate of false positives due to this antigenic cross-reactivity. Similarly, the results of xenodiagnostic procedures and epidemiological surveys of insect vectors are prone to distortion because of the close morphological resemblance of the epimastigote stages. The description of a T. cruzi epimastigote specific monoclonal antibody, 2A2, which reacts with both culture and insect derived epimastigotes provides a more reliable basis for differential diagnosis of these two parasites.

The affinity of the lectins Ricinus communis and Glycine maxima to carbohydrates on the cell surface of various forms of Trypanosoma cruzi and Trypanosoma rangeli, and the application of these lectins for the identification of T. cruzi in the feces of Rhodnius prolixus.

Flagellates of Trypanosoma cruzi (stock Molino 1), obtained from the intestine of experimentally infected Rhodnius prolixus, grown in cellular or acellular culture, as well as from the blood of infected mice, were examined by a direct fluorescence test using the lectins RCA (Ricinus communis-120) and SBA (soy bean agglutinin; Glycine maxima), conjugated with fluorescein isothiocyanate, for the detection of beta-D-galactose and alpha,beta-N-acetyl-D-galactosamine on the membranes of the flagellates. The same reactions were carried out using Trypanosoma rangeli (stock San Agustin), obtained from the intestine, hemo-lymph or salivary glands of experimentally infected R. prolixus, as well as from cultures and from the blood of experimentally infected CFW mice. The results indicate that the membrane of T. rangeli in the salivary glands of the vector contains beta-D-galactose, but that this sugar is absent from all other developmental stages of this trypanosome. All stages of intestinal and cultured. T. cruzi presented positive reactions with RCA-FITC and SBA-FITC. The high specificity of this technique makes it useful for the examination of R. prolixus, previously used in xenodiagnosis of Chagas' disease and for the examination of intradomiciliary or sylvatic vectors in epidemiological surveys in areas where T. cruzi and T. rangeli coexist. Formaldehyde fixed samples can be examined months later and false reports due to T. rangeli can be avoided.

Antibody response to experimental Trypanosoma rangeli infection and its implications for immunodiagnosis of South American trypanosomiasis.

Differential immunodiagnosis of T. rangeli and T. cruzi infections in man poses a particular problem, not only because these parasites share antigenic determinants, as detected by immunofluorescence, but also because they have a similar geographical distribution, the same host range and often identical insect vectors. We show here that whereas mouse anti-T. rangeli sera have significant cross reactivity with T. cruzi by immunofluorescence, they are entirely specific when tested by ELISA, using apparently similar antigen preparations. Immunoprecipitation analysis detected relatively little cross-reactivity between heterologous antisera and parasite combinations. Intriguingly, immunization with T. rangeli epimastigotes was much more powerful than similar immunization with trypomastigotes, and the majority of the antibody was directed against a single polypeptide of apparent Mr 73kDa.

Trypanosoma magdalenae sp. n (Protozoa: Kinetoplastida) from a freshwater teleost, Petenia kraussii, in Colombia.

A new, monomorphic trypanosome, Trypanosoma magdalenae sp. n. was found in five of 38 fish, Petenia kraussii, from the Río Magdalena in Colombia, South America. It is the first trypanosome species designated from freshwater teleosts in Colombia. The trypomastigotes measured in 42.4 micron +/- 2.05 SD (range, 39.8 - 45.6) by 2.1 micron +/- 0.20 (2.0 - 2.5). Their nuclear index was 1.6 micron +/- 0.22 (1.25 - 1.84) and their kinetoplastic index equaled 1.1 micron +/- 0.02 (1.08 - 1.15). Infection intensity was usually limited to two or three flagellates per 40 microliter of packed blood cells.

Babesia sp. in Colombian bats (Microchiroptera).

Two leaf-chinned bats (Mormoops megalophylla) collected in 1963 in central Colombia were heavily infected with Babesia sp., probably Babesia vesperuginis. Both bats had pronounced splenomegaly. This is the first report of a Babesia sp. infection of a bat in the Americas.

Trypanosoma (Herpetosoma) longiflagellum sp.n. from the tomb rat, Taphozous nudiventris, from Iraq.

Trypanosoma (Herpetosoma) longiflagellum sp.n. (Protozoa: Trypanosomatidae) from a bat, Taphozous nudiventris, from Iraq is described. The trypanosome measures 24.0 to 34.2 micron (mean 26.4 micron, SD 2.5) in total length, 13.8 to 18.2 micron (mean 15.2 micron, SD 1.0) in body length, is 1.5 to 2.9 micron (mean 2.0 micron, SD 0.3) in breadth and has a free flagellum of 10.2 to 16.0 micron (mean 11.2 micron, SD 1.6). The nuclear index is 1.4 to 2.1 (mean 1.7 SD 0.1) and the kinetoplastic index is 1.5 to 2.6 (mean 1.9, SD 0.2). This is the second report of a bat trypanosome belonging to the subgenus Herpetosoma and the first report of trypanosomes from bats from Iraq.

Trypanosoma (Herpetosoma) longiflagellum Sp.N. from the tomb bat, Taphozous nudiventris, from Iraq.

Trypanosoma (Herpetosoma) longiflagellum sp.n. (Protozoa: Trypanosomatidae) from a bat, Taphozous nudiventris, from Iraq is described. The trypanosome measures 24.0 to 34.2 micron (mean 26.4 micron, SK 2.5) in total length, 13.8 to 18.2 micron (mean 15.2 micron, SD 1.0) in body length, is 1.5 to 2.9 micron (mean 2.0 micron,SD 0.3) in breadth and has a free flagellum of 10.2 to 16.0 micron (mrsn 11.2 micron, SD 1.6). The nuclear index is 1.4 to 2.1 (mean 1.7 SD 0.1) and the kinetoplastic index is 1.5 to 2.6 (mean 1.9, SD 0.2). This is the second report of a bat trypanosome belonging to the subgenus Herpetosoma and the first report of trypanosomes from bats from Iraq.

The multiplication stages of Trypanosoma (Herpetosoma) xeri in the liver of the Sudanese ground squirrel Xerus (Euxerus) erythropus.

Blood and organ smears from 24 of 98 ground squirrels (Xerus erythropus) from the Sudan were infected with a trypanosome resembling Trypanosoma (Herpetosoma) xeri. The developmental stages are described from the liver of one heavily infected ground squirrel. Multiplication was by binary fission and numerous triangular amastigotes, sphaeromastogotes and trypomastigotes were observed. A tentative development cycle in the final host is presented.

Oswaldofilaria medemi n. sp. (Nematoda: Filarioidea), from the smooth-fronted caiman, Paleosuchus trigonatus from Colombia.

A filarial worm, Oswaldofilaria medemi n. sp., obtained from the thoracic wall of an adult colombian caiman, Paleosuchus trigonatus (Schneider, 1801) is described. The new filaria differs from all other species of the genus by the long oesophagus and by differences in size and shape of the spiculae in the male. Microfilariae could not be found in the blood of six P. trigonatus.

Developmental stages of Trypanosoma cruzi-like flagellates in Cavernicola pilosa.

The developmental stages of Trypanosoma cruzi ssp., found in the intestinal tract of Cavernicola pilosa, are described and measurements given for nine life stages. The frequencies of the various stages in foregut, midgut and hindgut of the triatomines are provided; parasites were rare in the foregut and metatrypomastigotes were seen only in the mid- and hindguts. All adult bugs examined harboured intestinal infections of T. cruzi-like flagellates, large clumps of amastigotes were frequently observed in the midgut. The faeces of C. pilosa, containing metacyclic trypomastigotes, did not produce patent parasitaemia when inoculated into mice. Inoculated mice were not protected against subsequent challenge infections with the highly virulent Tulahuen stock of T. c. cruzi. The blood of bats also failed to produce parasitaemia when inoculated into mice, nor were the mice protected against subsequent challenges with T. c. cruzi. Although the developmental stages described were very similar to those of T. c. cruzi it is presumed that they were stages of T. c. marinkellei because of their failure to infect mice and Rhodnius prolixus, and their failure to protect inoculated mice against challenge with T. c. cruzi.

A list of ectoparasites of Colombian bats.

Of 3,860 Colombian bats, belonging to 109 species, 1,235 individuals (32%) of 100 species were infected with ectoparasites. A total of 3,545 ectoparasites pertaining to 88 species were obtained (Mesostigmata: 1 Halarachnidae; 19 Macronyssidae; 4 Spelaeorhynchidae; 104 Spinturnicidae. Ixodides: 449 Argasidae. Trombidiformes: 1 Spelognathidae; 340 Trombiculidae. Sarcoptiformes: 170 Listrophoridae. Hemiptera: 16 Cimidae; 4 Polyctenidae. Diptera: 7 Nycteribiidae; 2405 Streblidae, Siphonaptera: 25 Pulicidae). No ectoparasites were recovered from 9 species of bats.

[Laboratory maintenance of Trypanosoma (Herpetosoma) rangeli Tejera, 1920]. / Mantenimiento en el laboratorio de Trypanosoma (Herpetosoma) rangeli Tejera, 1920.

Two laboratory maintenance systems of Trypanosoma rangeli were compared. The maintenance by weekly subinoculations in Tobie's culture medium and the intrafemoral inoculation of Rhodnius prolixus with cultured flagellates, resulted in loss of infectivity of the metacyclic salivarian trypomastigotes for mice, ten months after maintenance in culture. With the system of cyclical passes through culture-Rhodnius-mouse-culture-Rhodnius, the infectivity of the metacyclic trypomastigotes for mice, was maintained during the three years of the experiment. The number and percentage of metacyclic trypomastigotes formed in the salivary glands of R. prolixus, previously inoculated intrafemorally or intracoelomically with culture forms of T. rangeli, did not show correlation with the inoculated dose, however the inoculated quantity demonstrated a direct relation with the mortality rate of the insects. The results indicate that T. rangeli requires an adequate maintenance system, so that under experimental condition the biological characteristics, normally expressed under natural conditions, are conserved.

The control of leishmaniases.

Human leishmaniases are caused by at least 13 different species and subspecies of parasite of the genus Leishmania. These parasites are transmitted to man from other infected persons or mammals by sandflies when taking a blood meal. Leishmaniases have been reported from about 80 countries and probably some 400 000 new cases occur each year. Clinically the leishmaniases can be divided into three major groups: visceral leishmaniases, which are usually fatal if untreated; cutaneous leishmaniases, which often produce permanent facial disfigurement; and mucocutaneous leishmaniasis of the New World, which produces severe mutilation by destruction of the naso-oro-pharyngeal cavity and sometimes death. Since the various forms of leishmaniasis differ substantially from each other in their epidemiology, the strategy for control must be adapted to the local situation in each endemic area, after thorough ecological and epidemiological studies of the vectors, the hosts, and the landscape. If insufficient baseline information is available, failure of haphazardly applied control measures can be expected. Peridomestic insecticide spraying together with treatment of patients is effective in certain foci of anthroponotic cutaneous leishmaniasis, urban visceral leishmaniasis, and uta. Extensive programmes to eradicate desert rodents, combined with land reclamation, resulted in a considerable decrease in the incidence of zoonotic cutaneous leishmaniasis in vast areas of the USSR. Since control of zoonotic cutaneous/mucocutaneous leishmaniasis of the New World is hardly feasible at present, the only rational approach to prevent some of mucosal lesions is early diagnosis and radical treatment of patients with the rather unsatisfactory drugs at present available.

The effect of Lampit on Trypanosoma rangeli in experimentally infected mice.

Mice experimentally inoculated with metacyclic forms of Trypanosoma rangeli were given orally 10, 25, 50 or 100 mg/kg of body weight/day of Lampit on 20 consecutive days. The results of combined examinations of fresh blood, Giemsa stained blood preparations, blood cultures, blood concentration, repeated xenodiagnosis with Rhodnius prolixus and blind passages via triatomine bites to other mice demonstrated that a dose of 50 to 100 mg/kg/day of the drug eliminated T. rangeli from the blood of all mice in the first seven days of treatment. In mice receiving 10 or 25 mg/kg/day of drug, 60% and 30% respectively still harboured trypanosomes 90 days after infection. The results indicate that Lampit is at least as effective against T. rangeli as it is against T. cruzi in mice.

[Presence of neuraminidase in Rhodnius prolixus infected with Trypanosoma rangeli]. / Estudio sobre la presencia de neuraminidasa en Rhodnius prolixus infectado con Trypanosoma rangeli.

Using three different methods, the activity of neuraminidase was studied in the promesenteron, postmesenteron, rectal ampulla, haemolymph and salivary glands in 600 Rhodnius prolixus experimentally infected with Trypanosoma rangeli stock San Agustín. The haemagglutination method with peanut lectin, and the fluorescence test with peanut lectin conjugated with fluorescein isothiocyanate, and the fluorescence emitted by 4-methylumbelliferone showed in all cases the presence of neuraminidase in the supernatant culture of T. rangeli in Tobie's medium between 8 to 15 days growth. None of the three methods was able to detect the presence of neuraminidase in R. prolixus infected with T. Rangeli, thus suggesting that this enzyme is not produced in vivo, and consecutively is not implicated in the pathogenicity that this trypanosome has to its vector.