Trypanosomes In Blood Research Articles

Fluorescent Antibody Reactions in Trypanosoma rhodesiense and T. gambiense in Experimental Animals

A fluorescent antibody technique for the serodiagnosis of African trypanosomiasis in experimental animals is described. The indirect fluorescent antibody test employing the trypanosome form from rats as antigen appears to be highly sensitive in rabbits infected with T. rhodesiense and T. gambiense. Results of 29 sera from rabbits infected with T. rhodesiense organisms yielded 29 positive reactions, whereas 21 positive reactions and one weak reaction were obtained from 22 rabbits infected with T. gambiense organisms. The reproducibility of this test employing different lots of trypanosomes and labeled antiglobulin was good. Animals were inoculated with varying doses from 4 X to 5 X 106 trypanosomes and were bled at weekly intervals. Antibodies were detected between 1 and 2 weeks after inoculation with no apparent correlation between the early appearance of antibodies and the size of the inoculum as previously reported with helminthic infections. The similarity of observable reactions between the African trypanosomes and T. lewisi as antigen is of great interest. Since T. lewisi is nonpathogenic for humans and can be maintained readily in most laboratories, it is of great importance in areas where sufficient precautions cannot be taken to prevent human infections. Several parasitic protozoans have been stained with fluorescent antibody techniques (Goldman, 1953, 1957; Ristic et al., 1957; McEntegard et al., 1958). However, only rarely (Fife and Muschel, 1959; Tobie et al., 1961) has this procedure been successfully utilized for the immunodiagnosis of human protozoan infections. Recently a reliable and practical fluorescent antibody technique has been described for the serodiagnosis of schistosomiasis (Sadun et al., 1960). Adaptations of this test to permit the utilization of minute amounts of dried blood on filter paper and of preserved organisms have provided simple, rapid, and reliable serological techniques for the laboratory diagnosis of schistosomiasis (Sadun et al., 1961; Anderson et al., 1961a, 1961b) and trichinosis (Sadun et al., 1962b). The current report presents the results of studies in which the indirect fluorescent antibody technique was used to stain the various stages in the life cycle of T. rhodesiense and T. gambiense. Furthermore, attempts were made to determine the reproducibility of speReceived for publication 21 December 1962. cific immunological staining, to determine the time of initial appearance of antibodies in experimentally infected animals, and to determine whether organisms which are not pathogenic for man, such as T. lewisi, could be used as a source of antigen for the serological diagnosis of African trypanosomiasis. MATERIALS AND METHODS Trypanosoma rhodesiense (Wellcome strains) and T. gambiense (Wellcome and Cheick strains) maintained in albino rats and in cultures were used as the source of antigen. The rats were inoculated intraperitoneally with approximately 100,000 trypanosomes in rat blood diluted with 0.85% saline and subinoculated into healthy rats twice weekly. Trypanosome cultures were maintained on a diphasic blood agar medium (Tobie et al., 1950) and subinoculated into fresh cultures every 10 to 12 days. Antisera were obtained by bleeding rabbits from the medial artery of the ear at various intervals following a single intraperitoneal inoculation of varying numbers of trypanosomes. Estimates of the number of organisms in the inoculum were based on counts of trypanosomes in Hayem's red blood cell diluting fluid in a Neubauer cell-counting chamber. Thin smears were made on clean slides from rat tail blood or from the supernate of trypanosome cultures. Usually, 48 to 72 hr were required for

FLUORESCENCE MICROSCOPE EXAMINATION OF TRYPANOSOMES IN BLOOD

With acridinorange it is possible to stain selectively trypanosomes in blood intra-vitam. In subsequent examination by means of a fluorescence microscope only leucocytes and trypanosomes are visible (as shining bright green bodies), while the erythrocytes are not visible. Living and dead trypanosomes, too, may be distinguished in this way.With the fluorescent dye auramine, trypanosomes in blood may be selectively stained (showing up in golden fluorescence) so that diagnosis for trypanosomes is very greatly facilitated. Even in difficult cases a decision on the presence of trypanosomes in blood is possible.

A Trypanosome of Panamanian Cattle and a Method for concentrating Trypanosomes in Peripheral Blood

We have been able to show that a large percentage of the beef cattle brought to Panama City from various parts of the Republic of Panama carry in their blood a large trypanosome. Since these animals are apparently in good health, the presumption is that the trypanosome is nonpathogenic; however, another possibility is that the trypanosome is pathogenic, but that the cattle have developed an immunity against it.

On the Occurrence of Trypanosomes in the Blood of Rana clamata

On the Occurrence of Trypanosomes in the Blood of Rana clamata

Note on the Discovery of the Human Trypanosome

WE have recently seen in the medical Press several very inaccurate accounts regarding the authorship of the important new discovery of trypanosomes in human blood, and of the disease caused by them. For instance, the Journal of Tropical Medicine for November I (in giving an anonymous description, supported by an editorial, of a case just observed by Drs. Daniels and Manson) attributes the original discovery to Dr. R. M. Forde. It does not mention even the name of Dr. J. Everett Dutton. Dr. Dutton is an old student and assistant in this Laboratory, and is now away on the West African Coast; and we are of opinion that he has a claim to be considered in the matter of this discovery. Another periodical, The Hospital for November 8, while also omitting Dr. Dutton's name, states that the discovery was made “within the last few days” by the London School of Tropical Medicine. We believe that such statements are calculated to distort the history of the discovery, and should therefore like to have an opportunity for correcting them promptly in your pages.

Note on the Discovery of the Human Trypanosome

WE have recently seen in the medical Press several very inaccurate accounts regarding the authorship of the important new discovery of trypanosomes in human blood, and of the disease caused by them. For instance, the Journal of Tropical Medicine for November I (in giving an anonymous description, supported by an editorial, of a case just observed by Drs. Daniels and Manson) attributes the original discovery to Dr. R. M. Forde. It does not mention even the name of Dr. J. Everett Dutton. Dr. Dutton is an old student and assistant in this Laboratory, and is now away on the West African Coast; and we are of opinion that he has a claim to be considered in the matter of this discovery. Another periodical, The Hospital for November 8, while also omitting Dr. Dutton's name, states that the discovery was made “within the last few days” by the London School of Tropical Medicine. We believe that such statements are calculated to distort the history of the discovery, and should therefore like to have an opportunity for correcting them promptly in your pages.