The isoenzyme characteristics of Trypanosoma evansi and Trypanosoma equiperdum isolated from domestic stocks in China.

Twelve stocks of Trypanosoma evansi and one of Trypanosoma equiperdum isolated from domestic animals in China were examined for 16 enzymes using cellulose acetate and thin-layer starch gel electrophoresis. Differences were seen between stocks in only two of the enzymes, MDH and ALAT. Three of the T. evansi stocks, isolated from buffalo, and the T. equiperdum stock had the unusual pattern MDH-3, while all the other Chinese stocks had the common MDH-1. Two other stocks of T. evansi and again the T. equiperdum, all from equines, showed a new pattern ALAT-14. Otherwise the Chinese stocks had the same enzyme profile as T. evansi from elsewhere.

A simplified method for identifying subspecies and strain groups in Trypanozoon by isoenzymes.

To characterize trypanosomes from the subgenus Trypanozoon, 272 stocks in 111 zymodemes were analysed by the polymorphisms seen in a rationalized range of nine enzymes, resolved by electrophoresis, mostly on cellulose acetate. Several highly polymorphic or invariant enzymes used previously were omitted, while two new enzymes, NHD and SOD were included; the isoenzymes seen for SOD were interpreted as two separate enzymes, SODA and SODB. Isoenzyme band patterns were analysed by two complementary numerical methods to elucide taxonomic relationships within the subgenus; groups of zymodemes corresponding to subspecies and strain groups were defined, which agreed closely with previous studies. Except for one zymodeme, Trypanosoma evansi could not be clearly distinguished from the bouaflé strain group. This strain group had enzymic features that overlapped to some extent those of the busoga group. Trypanosoma brucei gambiense and the zambezi, kakumbi, kiboko and sindo groups were clearly defined. Eight zymodemes could not be classified. A rapid identification system using a limited number of enzymes is presented.

The substitution of procyclic for bloodstream form Trypanosoma brucei gambiense in isoenzyme studies.

Examination of 10 enzymes from 8 stocks of Trypanosoma brucei showed that procyclic forms could be substituted for bloodstream forms in isoenzyme studies. T. b. gambiense procyclic forms cultured in vitro offer a better source of material for genetic investigations because this species is usually of low infectivity and virulence to laboratory rodents. Using 6 stocks of T. b. gambiense and 2 stocks of T. b. brucei, enzyme patterns of bloodstream and procyclic forms were identical for isocitrate dehydrogenase, malic enzyme, two nucleoside hydrolases (utilizing inosine and deoxyinosine respectively), phosphoglucomutase and superoxide dismutase. Procyclic forms appeared to have greater threonine dehydrogenase activity than bloodstream forms. Consistent differences between bloodstream and culture forms were observed for alanine aminotransferase, aspartate aminotransferase and malate dehydrogenase. These agreed with known differences in the metabolism of procyclic and bloodstream forms.

Isoenzyme characterization of Trypanosoma evansi isolated from capybaras and dogs in Brazil.

Trypanosoma evansi was seen in blood samples taken randomly from both wild and semi-captive capybaras caught in Mato Grosso do Sul State, Brazil and in sick dogs brought into local veterinary clinics. Trypanosome stocks from capybaras and dogs were significantly different in their patterns of growth in mice, while the trypanosomes from dogs were mostly dyskinetoplastic. By isoenzyme electrophoresis all the trypanosomes were of the most common type of T. evansi found elsewhere.

Further enzyme polymorphism in Trypanosoma cruzi from Colombia.

The electrophoretic behavior of eleven soluble enzymes from three Colombian stocks of Trypanosoma cruzi was compared with representative stocks of three reference Brazilian zymodemes. Although separated by geographical barriers, the Colombian stocks showed the same isoenzyme profiles in 7 and 8 out of the eleven enzymes analyzed as the Brazilian reference zymodemes. The genetic distance separating the Colombian from the Brazilian zymodemes ranged from 0.25 to 0.46. However, even for this small sample, six new enzyme patterns and new combinations in enzyme profile were found. The existence of new zymodemes is indicated and a wider variation in T. cruzi isoenzyme types is demonstrated.

The isolation and isoenzyme characterization of Leishmania braziliensis subsp. from patients with cutaneous leishmaniasis acquired in Belize.

Leishmanial organisms were cultivated from cutaneous lesions of British military personnel returning from Belize. Isoenzyme profiles of the freshly isolated organisms and 'marker' strains of New World Leishmania spp. were compared using 10 enzymes (ALAT, ASAT, ME, GPI, MPI, PGM, SOD, 6-PGDH, G-6-PDH and MDH), by starch gel electrophoresis. 19 of the 22 new isolates from Belize were isoenzymically indistinguishable from Leishmania braziliensis braziliensis (10 out of 10 enzymes) and clearly differentiated from L. b. guyanensis and L. b. panamensis (different in 6 out of 10 enzymes) and from L. mexicana mexicana and L. m. amazonensis (9 out of 10 enzymes). Two isolates closely resembled L. m. mexicana and one could not be positively identified. This is the first report of autochthonous human leishmaniasis caused by L. braziliensis group organisms as far north as latitude 16 degrees N.

Aspartate aminotransferase in Leishmania is a broad-spectrum transaminase.

The substrate specificity of aspartate aminotransferase (ASAT, E.C. 2.6.1.1.) from Leishmania was examined following observations of artefacts on gels stained for alanine aminotransferase (ALAT, E.C. 2.6.1.2.) after thin-layer starch-gel electrophoresis. Leishmanial ASAT acted on L-aspartate, L-alanine, L-tryptophan and L-tyrosine. Interpretation of ALAT zymograms must thus take into account the presence of interfering ASAT bands, and the need is emphasized for rigorous controls in isoenzyme electrophoresis.

Anion-exchange separation for neotropical trypanosomes: a preliminary trial and a description of Trypanosoma devei from the tamarin Saguinus midas niger.

Anion-exchange separation trials using DEAE-cellulose columns were performed with blood from two single species of marsupial and edentate, three species of rodent and single species of carnivore, primate, cayman and lizard. Trypanosoma cruzi was isolated from Didelphis marsupialis, Dasypus novemcinctus and Coendou sp. T. (Megatrypanum) devei was isolated from the tamarin Saguinus midas niger and the mensural characters of the organism were redescribed. Anion-exchange separation was considered to be a valuable procedure for the taxonomist searching for new or little-known trypanosomes.

Isoenzymes in two species of Acholeplasma.

The reference strains Type A and Type B and two equine strains of Acholeplasma laidlawii were examined for a wide range of isoenzymes using thin-layer starch-gel electrophoresis; in addition two isoenzymes were examined in two strains of A. equifetale. The type strains A and B of A. laidlawii were differentiated by their lactate dehydrogenase, phosphoglucomutase and aspartate aminotransferase patterns and the two equine strains by their hexokinase, lactate dehydrogenase and phosphoglycerate kinase patterns. The two pairs of strains differed from one another with respect to hexokinase, phosphoglucomutase, adenylate kinase and glucose-6-phosphate dehydrogenase. The two strains of A. equifetale could be distinguished by their isoenzymes of hexokinase. The two species were differentiated by their hexokinase and phosphoglucomutase patterns.

The identification of Trypanosoma brucei gambiense in Liberian pigs and dogs by isoenzymes and by resistance to human plasma.

29 Trypanozoon stocks from Liberian pigs and dogs were screened for human plasma resistance and electrophoretic isoenzyme patterns of eleven enzymes. Two stocks from pigs were found both to be resistant to human plasma and to have an isoenzyme marker, a slow alanine aminotransferase (ALAT) pattern, previously found only in Trypanosoma brucei gambiense from man. This constitutes evidence that the pig is a reservoir of human trypanosomiasis in West Africa. The T.b.gambiense ALAT was also found in stocks from 5 other pigs and a dog, but none of these stocks was resistant to human plasma; conversely, 9 further isolations from pigs and 2 from dogs were plasma resistant but did not have the T.b.gambiense ALAT. The lack of correspondence between the two characteristics is discussed. A T.b.gambiense stock from man in Zaire had the ALAT pattern characteristic of T.b.gambiense from Senegal and Nigeria, together with the ASAT triplet found in most T.b.gambiense stocks. Peptidase polymorphism was shown in trypanosomes for the first time.