RESUMEN
We studied Aotus lemurinus, Panamanian night monkeys, for susceptibility to Toxoplasma infection and for their capacity to develop immunity using either sufadiazine prophylaxis or the non-persistent ts-4 vaccine. The animals were highly susceptible to infection with a mouse pathogenic (T265) and a mouse nonpathogenic (T163) Toxoplasma isolate. A calculated single bradyzoite by mouth gave rise to infection which was fatal in nine to 12 days. Chemoprophylaxis with 60-300 of sulfadiazine mg per day for up to 40 days protected the animals; however this was followed by fatal reactivation of infection between 11 and 70 days after treatment was stopped. Vaccination was carried out in two or three doses subcutaneously. Challenge was performed in 26 animals using both Toxoplasma isolates. Five monkeys (19%) survived for over a year, 10 died after a prolonged illness, and 11 died as rapidly as the seven controls. Safety tests showed the vaccine to be nonpathogenic in 111 adults except for slight fever and local inflammation, although one of four juveniles died from disseminated infection. Vaccination of 25 pregnant monkeys was non-pathogenic; however two of 25 fetuses were aborted, one of which was infected and one newborn had microphthalmia, retinitis and a cataract; four of the offspring were not tested. When six lactating monkeys were vaccinated, Toxoplasma was not transmitted to the infants. The high susceptibility to Toxoplasma and the low immunizability was circumstantially attributed to absence of exposure and lack of selection by Toxoplasma of these arboreal monkeys even though about 50% of terrestrial animals from the same area were infected.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Aotus trivirgatus , Modelos Animales de Enfermedad , Vacunas Antiprotozoos , Toxoplasma/inmunología , Toxoplasmosis Animal/prevención & control , Animales , Anticuerpos Antiprotozoarios/análisis , Femenino , Hipersensibilidad Tardía , Lactancia , Embarazo , Complicaciones Infecciosas del Embarazo/inmunología , Complicaciones Infecciosas del Embarazo/prevención & control , Vacunas Antiprotozoos/inmunología , Sulfadiazina/uso terapéutico , Toxoplasmosis Animal/inmunología , VacunaciónRESUMEN
We have compared the growth of the wild type Plasmodium falciparum strain Honduras 1 and a previously isolated temperature sensitive mutant of it, AP1-16, in Panamanian owl monkeys. We examined serially infected splenectomized and normal animals that were initially infected with cultured parasites that had been grown in a mixture of owl monkey and human erythrocytes. Initial infections in splenectomized monkeys were marked by multiple recrudescences. The mutant grew less well than the wild type in the splenectomized monkeys, as determined by lower peak and total parasitemias. In the splenectomized monkeys tested by rechallenge with the wild type parasite, the mutant stimulated a comparable degree of protection. That protection was manifested in 2 ways. There was a marked reduction in the level of the primary parasitemia in the rechallenged monkeys and an absence of recrudescent parasitemias after the primary parasitemia. The potential value of generating and studying temperature sensitive P. falciparum strains that show attenuated growth is considered.
Asunto(s)
Malaria/parasitología , Plasmodium falciparum/crecimiento & desarrollo , Animales , Aotus trivirgatus , Malaria/sangre , Malaria/inmunología , Mutación , Plasmodium falciparum/genética , Plasmodium falciparum/inmunología , Esplenectomía , TemperaturaRESUMEN
The effects of four halogenated analogs of histidine on in vitro growth of Plasmodium falciparum malaria parasites were monitored by measurement of the incorporation of 3H-labeled amino acids into parasite proteins and by light and electron microscopy. The uptake of [3H]isoleucine was reduced to 50% of the control value by addition of 70 microM 2-fluoro-L-histidine (2-F-HIS) or 420 microM 2-iodo-L-histidine (2-I-HIS). [3H]histidine uptake into acid-insoluble material was affected equally by these two compounds, 50% inhibition resulting at 200 microM concentration. Morphological analysis of parasite development proved a sensitive assay, since development of mature trophozoites was inhibited 50% by 25 microM 2-F-HIS or 100 2-I-HIS. Electron microscopy studies suggested different mechanisms of action of 2-F-HIS and 2-I-HIS on P. falciparum. 2-F-HIS produced a decrease in knob number at the erythrocyte surface and accumulation of electron-dense material under the parasite membrane. 2-I-HIS had no obvious effect on knobs or electron-dense material but affected parasite morphology. Surprisingly, 2-chloro-L-histidine and 2-bromo-L-histidine did not inhibit P. falciparum in vitro, even though their halogen atom substituents are intermediate in size between F and I atoms. 2-F-HIS and 2-I-HIS were tested in vivo against P. falciparum in owl monkeys (Aotus sp.) but were ineffective at doses that were nontoxic.
Asunto(s)
Antimaláricos , Histidina/análogos & derivados , Plasmodium falciparum/efectos de los fármacos , Aminoácidos/metabolismo , Animales , Aotus trivirgatus , Membrana Celular/ultraestructura , Histidina/farmacología , Técnicas In Vitro , Malaria/prevención & control , Microscopía Electrónica , Plasmodium falciparum/metabolismo , Plasmodium falciparum/parasitologíaRESUMEN
Seemingly intact cysts and sequential stages of disintegrating cysts of Toxoplasma were identified immunohistologically within developing microglial nodules in a Panamanian night monkey (Aotus lemurinus). This monkey had been successfully immunized and challenged 5 months earlier. This supports the hypothesis that glial nodules unassociated with Toxoplasma tachyzoites may represent the tombstone of a Toxoplasma cyst. Disintegration of cysts may give rise to clinical encephalitis in the presence of apparently adequate immunity.
Asunto(s)
Encéfalo/parasitología , Encefalitis/etiología , Toxoplasma/citología , Toxoplasmosis Animal/parasitología , Animales , Aotus trivirgatus , Encéfalo/patología , Encefalitis/parasitología , Encefalitis/patología , Hipersensibilidad Tardía , Médula Espinal/parasitología , Médula Espinal/patología , Toxoplasmosis Animal/inmunología , Toxoplasmosis Animal/patologíaRESUMEN
Clinical observation has suggested that iron deficiency may be protective in malaria, and we have found that desferrioxamine (DF), an iron-specific chelating agent, inhibited Plasmodium falciparum growth in vitro. It was difficult to be confident that DF would be effective in an intact animal, however, because continuous exposure to DF was required in vitro and, in vivo, DF is rapidly excreted. Also, the in vitro effect of DF was overcome by addition of iron to the culture and in vivo there are potentially high local iron concentrations when iron is absorbed from the diet or released from reticuloendothelial cells. We now show that DF given by constant subcutaneous infusion does suppress parasitemia in P. falciparum-infected Aotus monkeys.
Asunto(s)
Deferoxamina/farmacología , Malaria/tratamiento farmacológico , Plasmodium falciparum/crecimiento & desarrollo , Animales , Aotus trivirgatus , Deferoxamina/uso terapéutico , Plasmodium falciparum/efectos de los fármacosRESUMEN
Parameters of blood-induced infections of the Vietnam Oak Knoll, Vietnam Smith, and Uganda Palo Alto strains of Plasmodium falciparum studied in 395 Panamanian owl monkeys in this laboratory between 1976-1984 were compared with those reported from another laboratory for 665 Colombian owl monkeys, studied between 1968-1975, and, at the time, designated Aotus trivirgatus griseimembra. The virulence of these strains was less in Panamanian than in Colombian owl monkeys, as indicated by lower mortality rates of the Panamanian monkeys during the first 30 days of patency. Maximum parasitemias of the Vietnam Smith and Uganda Palo Alto strain, in Panamanian owl monkeys dying during the first 15 days of patent infection, were significantly higher than in Colombian owl monkeys. Panamanian owl monkeys that survived the primary attack had significantly higher maximum parasitemias than the surviving Colombian owl monkeys. Peak parasitemias were attained significantly earlier after patency in Panamanian than in Colombian owl monkeys, irrespective of the strain of P. falciparum. More Panamanian than Colombian owl monkeys evidenced self-limited infection after the primary attack of either the Vietnam Smith or Uganda Palo Alto strain. The duration of the primary attacks and recrudescences were significantly shorter in Panamanian than in Colombian owl monkeys. Mean peak parasitemias during recrudescence were usually higher in Panamanian owl monkeys than in Colombian monkeys. Differences of infection parameters were probably attributable, in part, to geographical origin of the two monkey hosts and parasite strains.
Asunto(s)
Aotus trivirgatus , Cebidae/parasitología , Modelos Animales de Enfermedad , Malaria/parasitología , Animales , Colombia , Susceptibilidad a Enfermedades , Malaria/sangre , Malaria/mortalidad , Panamá , Plasmodium falciparum/patogenicidad , Especificidad de la Especie , VirulenciaAsunto(s)
Antimaláricos/uso terapéutico , Aotus trivirgatus , Cebidae , Modelos Animales de Enfermedad , Malaria/tratamiento farmacológico , Plasmodium falciparum/efectos de los fármacos , Animales , Antimaláricos/farmacología , Aotus trivirgatus/parasitología , Cebidae/parasitología , Farmacorresistencia Microbiana , Plasmodium falciparum/crecimiento & desarrolloRESUMEN
Retrospective pathology data from necropsies of 162 marmosets, Saguinus oedipus, were studied to determine the nature of chronic wasting syndrome, a poorly defined entity associated with a high mortality rate in many marmoset colonies. Paraffin sections of the gastroenteric organs of 116 of these marmosets were re-examined in detail; lesions were identified, quantitated, and analyzed with a method of multiple chi-square testing for possible associations between findings. Five distinct disease entities were identified: prosthenorchosis, amebiasis, paramyxovirus disease, sepsis, and chronic colitis. Lesions of several of these often occurred in the same monkey, and all but the first were associated with cachexia. Lesions of chronic colitis were crypt abscesses, mononuclear and polymorphonuclear infiltration of the lamina propria, epithelial cell atypia, karyorrhexis, and lymphoid hyperplasia. The cause of chronic colitis was not identified, nor was any explanation found for weight loss and increased susceptibility to disease.
Asunto(s)
Callitrichinae , Sistema Digestivo/patología , Enfermedades de los Monos/patología , Animales , Peso Corporal , Colitis/veterinaria , Colon/patología , Femenino , Mucosa Intestinal/patología , Ganglios Linfáticos/patología , Masculino , Peritonitis/veterinaria , Infecciones por Respirovirus/veterinaria , Estadística como Asunto , Estómago/patología , Tricomoniasis/veterinariaRESUMEN
Retrospective pathology data from necropsies of 162 marmosets, Saguinus oedipus, were studied to determine the nature of chronic wasting syndrome, a poorly defined entity associated with a high mortality rate in many marmoset colonies. Paraffin sections of the gastroenteric organs of 116 of these marmosets were re-examined in detail; lesions were identified, quantitated, and analyzed with a method of multiple chi-square testing for possible associations between findings. Five distinct disease entities were identified: prosthenorchosis, amebiasis, paramyxovirus disease, sepsis, and chronic colitis. Lesions of several of these often occurred in the same monkey, and all but the first were associated with cachexia. Lesions of chronic colitis were crypt abscesses, mononuclear and polymorphonuclear infiltration of the lamina propria, epithelial cell atypia, karyorrhexis, and lymphoid hyperplasia. The cause of chronic colitis was not identified, nor was any explanation found for weight loss and increased susceptibility to disease.
Asunto(s)
Caquexia/veterinaria , Callithrix , Colitis/veterinaria , Enfermedades Gastrointestinales/veterinaria , Animales , Caquexia/etiología , Caquexia/mortalidad , Enfermedad Crónica , Colitis/complicaciones , Colitis/patología , Femenino , Enfermedades Gastrointestinales/complicaciones , Enfermedades Gastrointestinales/patología , Masculino , Estudios RetrospectivosRESUMEN
The presence of antibody to hepatitis A virus (anti-HAV) in 60% of procured owl monkeys (Aotus trivirgatus) held within the United States prompted a study of recently captured A trivirgatus in Panama. Only 2 of 145 newly captured monkeys, but all of 35 A trivirgatus held within a colony for over 100 days, were found to have anti-HAV. Of 41 sero-negative, newly captured monkeys followed prospectively, 25 became infected with hepatitis A virus (HAV) as evidenced by seroconversion or demonstration of virus in the liver at death. Only one monkey that survived over 60 days within the colony was not infected. HAV was identified in the feces of most infected monkeys prior to the development of antibody and was antigenically indistinguishable from human HAV in cross-blocking radioimmunoassays. This colony-centered epizootic provides strong evidence that A trivirgatus is susceptible to HAV and should be investigated further as a potential model of human hepatitis A.
Asunto(s)
Aotus trivirgatus/microbiología , Cebidae/microbiología , Hepatitis A/veterinaria , Enfermedades de los Monos/transmisión , Animales , Anticuerpos Antivirales/análisis , Antígenos Virales/análisis , Heces/microbiología , Femenino , Hepatitis A/microbiología , Hepatitis A/transmisión , Anticuerpos de Hepatitis A , Hepatovirus/inmunología , Humanos , Masculino , Enfermedades de los Monos/microbiología , Panamá , Estudios ProspectivosRESUMEN
Four cotton-top tamarins were fed a commercial biscuit diet and three others a commercial canned diet for 12 weeks. Thereafter, all seven were fed a purified diet for 12 weeks. General health, body weight, food intake, fecal output, serum biochemistry, blood count, and colonic histopathology were evaluated at various times during the experiments. The diets did not affect these parameters except the purified diet was associated with relatively reduced fecal output. Diarrhea and chronic colitis occurred independently of the diet in three tamarins in the course of the study.