Histopathology of murine toxoplasmosis under treatment with dialyzable leukocyte extract.

BACKGROUND: Dialyzable leukocyte extracts (DLEs) contain molecules smaller than 10 kDa with biological activity in receptor organisms. Primarily, they participate in the regulation of the Th1 immune response, which is essential for the control of several intracellular infections, such as toxoplasmosis. This disease is associated with congenital infection, encephalitis or systemic infections in immunocompromised individuals. The clinical course of this infection fundamentally depends on a well-regulated immune response and timely treatment with the appropriate drugs. OBJECTIVE: The aim of this study was to evaluate the effect of treatment with a leukocyte extract, derived from crocodile lymphoid tissue, on the histopathology and brain parasite load in NIH mice that had been infected with cysts of Toxoplasma gondii (ME-49 strain). METHODS: The treatment was applied during the acute and chronic stages of the infection. Histopathological changes were evaluated in the ileum, liver and spleen at one, four and eight weeks after infection and in the brain at week 8. The parasite load was evaluated by counting the cysts of T. gondii found in the brain. FINDINGS: Compared to the control mouse group, the mice infected with T. gondii and under treatment with DLE showed less tissue damage, mainly at the intestinal, splenic and hepatic levels. In addition, a greater percentage of survival was observed, and there was a considerable reduction in the parasite load in the brain. CONCLUSIONS: The results suggest that DLE derived from crocodile is a potential adjunctive therapy in the conventional treatment of toxoplasmosis.

Histopathology of murine toxoplasmosis under treatment with dialyzable leukocyte extract

BACKGROUND Dialyzable leukocyte extracts (DLEs) contain molecules smaller than 10 kDa with biological activity in receptor organisms. Primarily, they participate in the regulation of the Th1 immune response, which is essential for the control of several intracellular infections, such as toxoplasmosis. This disease is associated with congenital infection, encephalitis or systemic infections in immunocompromised individuals. The clinical course of this infection fundamentally depends on a well-regulated immune response and timely treatment with the appropriate drugs. OBJECTIVE The aim of this study was to evaluate the effect of treatment with a leukocyte extract, derived from crocodile lymphoid tissue, on the histopathology and brain parasite load in NIH mice that had been infected with cysts of Toxoplasma gondii (ME-49 strain). METHODS The treatment was applied during the acute and chronic stages of the infection. Histopathological changes were evaluated in the ileum, liver and spleen at one, four and eight weeks after infection and in the brain at week 8. The parasite load was evaluated by counting the cysts of T. gondii found in the brain. FINDINGS Compared to the control mouse group, the mice infected with T. gondii and under treatment with DLE showed less tissue damage, mainly at the intestinal, splenic and hepatic levels. In addition, a greater percentage of survival was observed, and there was a considerable reduction in the parasite load in the brain. CONCLUSIONS The results suggest that DLE derived from crocodile is a potential adjunctive therapy in the conventional treatment of toxoplasmosis.

Analysis of Kinetoplast DNA from Mexican Isolates of Leishmania (L.) mexicana.

This study analyzed DNA minicircles of Mexican isolates of L. (Leishmania) mexicana to look for genetic differences between strains isolated from patients with diffuse cutaneous (DCL) and localized (LCL) leishmaniasis. The kDNA was analyzed using polymerase chain reaction (PCR), restriction fragment polymorphism analysis of the PCR products (PCR-RFLP) and the PCR products were sequenced. In the PCR with primers specific for the subgenus Leishmania, the Mexican isolates gave higher amplification products than the other L. mexicana complex strains and with specific primers for the L. mexicana complex they were poorly amplified. In the PCR-RFLP analysis with the Eco RV, Hae III, and Mbo I endonucleases, the Mexican isolates displayed similar restriction patterns, but different from the patterns of the other members of the L. mexicana complex. In the phylogenetic tree constructed, the kDNA sequences of the Mexican clones formed two groups including sequences of LCD or LCL clones, apart from the other L. mexicana complex members. These results suggest that the kDNA minicircles of the Mexican isolates are more polymorphic than the kDNA of other members of the L. mexicana complex and have different recognition sites for the restriction enzymes used in this study.

The intraperitoneal inoculation of Lactobacillus casei in mice induces total protection against Trichinella spiralis infection at low challenge doses.

The following effects of Lactobacillus casei in NIH mice were evaluated: the establishment of Trichinella spiralis adult worms in the intestine (AWI), larvae per gram of muscle tissue (LPG), levels of IgG and IgA, and levels of IL-4 and IFN-γ. One hundred and eight mice were allocated at random into 18 groups of six mice each. Each mouse in treated or non-treated groups was inoculated intraperitoneally once a week during 6 weeks with L. casei or phosphate-buffered solution. Later each mouse was challenged either with 200, 50, or 25 T. spiralis infective larvae. When the infection dose was 200 T. spiralis infective larvae, the reductions in AWI were 78.6% at 4 days after infection (dai) and 76.7% at 10 dai; while the reduction of LPG was 80.9% with respect to control groups. When the infection dose was 50 or 25 T. spiralis infective larvae, the reductions of AWI were 100% both at 4 and 10 dai; while the reduction of LPG at 30 dai was also 100% with respect to control groups. The levels of IgG and IgA anti-T. spiralis and IL-4 were significantly higher (P < 0.01) at 4 and 10 dai in mice from groups treated with L. casei than in animals in control groups; while at 10 dai, the levels of IFN-γ were higher in control mice (P < 0.01) than in L. casei-treated animals. The results suggest that frequent treatment of mice with L. casei induces a total protection against infection with low doses of T. spiralis.

Effect of Lactobacillus casei Shirota strain intraperitoneal administration in CD1 mice on the establishment of Trichinella spiralis adult worms and on IgA anti-T. spiralis production.

The effect of the intraperitoneal (ip) administration of Lactobacillus casei Shirota strain (LcS) in CD1 mice on the establishment of Trichinella spiralis adult worms (TSAW), and on the generation of intestinal IgA anti-T. spiralis after challenge (AC) were evaluated. One hundred and twenty mice were allocated at random into two groups of 60 mice each: Treated group (T) and Non-treated group (NT). Each mouse in T group was inoculated with LcS at days -21, -14, and -7. On day 0 each mouse was challenged with 200 larvae of T. spiralis. At days 3, 5, 7, 10, 12, 14, 17, 19, 21, and 28 AC, six mice from each group were sacrificed to obtain TSAW. At days 7, 14, 21, and 28 IgA-s anti-T. spiralis levels in intestinal washings were evaluated by ELISA. From day five on AC, mice in LcS group showed significantly less TSAW (P<0.05) than animals from NT group. At days 7, 14, 21, and 28 AC IgA anti-T. spiralis levels were higher in mice from T group (P<0.05) than in the NT group. The results indicate that LcS inoculated into mice induces protection against T. spiralis and an increase in the production of IgA anti-T. spiralis.

Protection against Toxoplasma gondii brain cyst formation in mice immunized with Toxoplasma gondii cytoskeleton proteins and Lactobacillus casei as adjuvant.

The aim of the study was to evaluate the protection generated in mice against Toxoplasma gondii brain cyst burden by vaccination with T. gondii cytoskeleton proteins using Lactobacillus casei as adjuvant. One hundred and sixty-eight NIH mice were randomly allocated into eight groups of 21 mice each. Animals were immunized as follows: in group 1 with Toxoplasma lysate antigen (TLA) in Freund's modified adjuvant, containing L. casei (FMA), in group 2 with Toxoplasma cytoskeleton proteins (TCPs) in FMA, in group 3 with FMA, in group 4 with phosphate buffered saline (PBS), in group 5 with L. casei dead by heath (Lc), in group 6 with Freund's complete adjuvant (FCA), in group 7 with TLA in FCA, and in group 8 with TCP in FCA. Mean brain cyst burden (+/-S.E.M.) was assessed in mice 8 weeks after challenge with T. gondii Me49 strain (20 cysts per mouse). The percentages of reduction in cyst burden per brain (P<0.01) as compared with the group 4 (control: mean 3181+/-97.5) were 77.25% (724+/-98) in group 1, 88.02% (381+/-97.5) in group 2, 38.92% (1943+/-130.3) in group 3, 44.31% (1771.4+/-102) in group 5, 59.28% (1295.2+/-99.1) in group 7 and 55.69% (1409.5+/-89.9) in group 8. In order of importance, the best protection was obtained in groups 2, 1, 7, 8, 5 and 3. Noticeably the mice inoculated with L. casei alone showed a significant reduction in T. gondii brain cysts (P<0.01), while those animals treated with FCA alone did not. Additionally, IgM anti-T. gondii antibody levels, as determined by ELISA 2 weeks after challenge, were highest in group 2 (P<0.01) than in the other seven groups. Results suggest that T. gondii cytoskeleton proteins with L. casei as adjuvant constitute a good anti-toxoplasmosis vaccine candidate.

La inoculación de Lactobacillus casei en ratones NIH induce una respuesta protectora contra la infección por Trypanosoma cruzi (cepa Ninoa) / The inoculation of Lactobacillus casei in NIH mice induces a protective response against Trypanosoma cruzi(Ninoa strain) infection

The aim of the present study was to evaluate the effect of Lactobacillus casei administered orally or intraperitoneally to NIH mice, on the experimental infection with Trypanosoma cruzi Ninoa strain. Twenty three NIH mice were randomly distributed into three groups, which were treated seven days before the infection with 12 x 10(4) Trypanosoma cruzi, Ninoa strain. The animals in the control group (n = 7) received sterile saline solution by intraperitoneal (ip) route; those in the Lc-O group (n = 8) were treated with Lactobacillus casei by oral route, and those in the Lc-IP group (n = 8) received L. casei by ip. The mice treated with the lactobacilli showed a reduced number of blood parasites after challenge, as compared with those of the control group (P < 0.01). Similarly, the mice treated with L. casei by ip route showed a significant minor total number of parasites after challenge, than those of the group treated with L. casei by oral route (P < 0.05). The results suggest that the treatment of mice with L. casei, both orally and intraperitoneally, induces a protective response against the experimental infection with Trypanosoma cruzi Ninoa strain.

El objetivo del presente estudio fue evaluar el efecto de Lactobacillus casei administrado por vía oral o intraperitoneal a ratones NIH, en la infección experimental con Trypanosoma cruzi cepa Ninoa. Se distribuyeron al azar 23 ratones NIH en tres grupos, los cuales fueron tratados siete días antes de la infección con 12 x 10(4) Trypanosoma cruzi, cepa Ninoa. Los animales en el grupo testigo (n = 7) recibieron solución salina estéril por vía intraperitoneal (ip); los del grupo Lc-O (n = 8), Lactobacillus casei vía oral, y los del grupo Lc-IP (n = 8) recibieron L. casei vía ip. Los ratones tratados con lactobacilos mostraron un número reducido de parásitos sanguíneos después de la confrontación, en comparación con el grupo testigo (P < 0.01). A su vez, los ratones tratados con L. casei vía ip mostraron un número total significativamente menor de parásitos sanguíneos después de la confrontación, que el observado en el grupo tratado con L. casei vía oral (P < 0.05). Los resultados sugieren que el tratamiento de ratones, tanto por vía oral como ip con L. casei, induce respuesta protectora contra la infección experimental con Trypanosoma cruzi cepa Ninoa.

Lactobacillus casei ssp. rhamnosus enhances non specific protection against Plasmodium chabaudi AS in mice

OBJECTIVE: To evaluate the capacity of Lactobacillus casei ssp. rhamnosus to enhance resistance against Plasmodium chabaudi chabaudi AS. MATERIAL AND METHODS: NIH mice were IP injected with viable lactobacillus casei seven days (LC1 group) or 7 and 14 days (LC2 group) before the challenge (day 0) with Plasmodium chabaudi parasitized red blood cells (pRBC). Control mice were inoculated with pRBC only. When parasitaemia was resolved, naive mice were injected with spleen cells from each group. The parasitaemia was measured. Nitric oxide (NO.) in serum was determined. RESULTS: Mice from the LC1 group presented a reduction in parasitaemia, with a prepatent period of five days, parasitaemia lasted 11 days, and the peak was (36.3 percent pRBC) on the 12th day post-infection. Mice from the LC2 group showed a prepatent period of five days, parasitaemia lasted eight days, and the peak (30 percent pRBC) was of on the 11th day. In the control, the prepatent period was three days, the parasitaemia lasted 15 days, and the peak (51 percent pRBC) was on day nine. Mice inoculated with spleen cells from the LC2 group showed a prepatent period of 21 days, parasitaemia lasted seven days, and the peak (13.5 percent pRBC) was on the 26th day. CONCLUSION: L. casei enhanced nonspecific resistance to P. chabaudi, as indicated by longer prepatent periods, reduced parasitaemia, and reduction in the viability of the parasites recovered from the spleen of infected mice, along with high concentrations of NO. in serum.

OBJETIVO: Evaluar la capacidad de Lactobacillus casei de aumentar la resistencia a la infección con Plasmodium chabaudi en ratones. MATERIAL Y MÉTODOS: Ratones NIH fueron inyectados intraperitonealmente con L. casei viable 7 días (grupo LC1) o 7 y 14 días (grupo LC2) antes del reto (día 0) con glóbulos rojos parasitados (GRP) con P. chabaudi. Los testigos fueron inoculados con GRP solamente. Cuando la parasitemia se resolvió, se inocularon ratones limpios con células de bazo de cada grupo. Se midió la concentración de óxido nítrico (NO.) en suero. RESULTADOS: El grupo LC1 presentó un periodo prepatente de 5 días, una parasitemia de 11 días con el máximo (36.3 por ciento de GRP) el día 12. Los ratones del grupo LC2 mostraron un periodo prepatente de 5 días, una parasitemia de 8 días con el pico (30 por ciento de GRI) el día 11. En los testigos el periodo prepatente fue de 3 días, la parasitemia de 15 y su máximo (51 por ciento de GRI) el día 9. Los ratones que recibieron células de bazo del grupo LC2, mostraron un período prepatente de 21 días, una parasitemia de 7 con su máximo (13.5 por ciento de GRI) el día 26. CONCLUSION: L. casei aumenta la resistencia no específica hacia P. chabaudi a juzgar por los periodos prepatentes más largos, las bajas parasitemias, la reducción en la viabilidad y la elevación de la concentración de NO. en el suero, que presentaron los ratones estimulados con lactobacilos.

Lactobaciilus casei ssp. rhamnosus enhances non specific protection against Plasmodium chabaudi AS in mice.

OBJECTIVE: To evaluate the capacity of Lactobacillus casei ssp. rhamnosus to enhance resistance against Plasmodium chabaudi chabaudi AS. MATERIAL AND METHODS: NIH mice were IP injected with viable lactobacillus casei seven days (LC1 group) or 7 and 14 days (LC2 group) before the challenge (day 0) with Plasmodium chabaudi parasitized red blood cells (pRBC). Control mice were inoculated with pRBC only. When parasitaemia was resolved, naive mice were injected with spleen cells from each group. The parasitaemia was measured. Nitric oxide (NO*) in serum was determined. RESULTS: Mice from the LC1 group presented a reduction in parasitaemia, with a prepatent period of five days, parasitaemia lasted 11 days, and the peak was (36.3 % pRBC) on the 12th day post-infection. Mice from the LC2 group showed a prepatent period of five days, parasitaemia lasted eight days, and the peak (30 % pRBC) was of on the 11th day. In the control, the prepatent period was three days, the parasitaemia lasted 15 days, and the peak (51% pRBC) was on day nine. Mice inoculated with spleen cells from the LC2 group showed a prepatent period of 21 days, parasitaemia lasted seven days, and the peak (13.5% pRBC) was on the 26th day. CONCLUSION: L. casei enhanced nonspecific resistance to P. chabaudi, as indicated by longer prepatent periods, reduced parasitaemia, and reduction in the viability of the parasites recovered from the spleen of infected mice, along with high concentrations of NO* in serum.

Inducción de resistencia contra Toxoplasma gondii en ratones NIH tratados con concanavalina A / Induction of resistence against Toxoplasma gondii in NIH mice treated with concanavalin A

Se evaluó el efecto de la administración de concanavalina A (Con A) en ratones expuestos a Toxoplasma gondii. Cuarenta y ocho ratones, cepa NIH (hembras de 22 a 24 g), libres de parásitositos, fueron distribuidos al azar en ocho grupos (A1, A2, B1, B2, C1, C2, D1, D2) de seis animales cada uno. Estos, fueron inoculados por vía intraperitoneal (i.p.) de la siguiente manera: los de los grupos A, B y C recibieron 10, 20 y 40 µg de Con A, respectivamente, mientras que los del grupo D recibieron 0.1 ml de solución salina fisiológica. Todos los ratones fueron confrontados por vía i.p. con 2 LD DE T. gondii, cepa RH. Los de los grupos A1, B1, C1 y D1 fueron expuestos al protozoario dos días después del tratamiento; mientras que los de los grupos A2, B2, C2 y D2, siete días después de éste. Los porcentajes de animales sobrevivientes obtenidos 15 días después de la infección, fueron 16.66, 16.66, 0, 0, 33.33, 50, 16.66 y 0 para los grupos A1, B1, C1, D1, A2, B2, C2 y D2, respectivamente. Para corroborar los resultados obtenidos en los últimos cuatro grupos, se repitió el experimento, después del cual se observaron consecuencias similares, excepto que en el grupo tratado con 40 µg de Con A, se obtuvo una sobrevivencia del 33.33 por ciento. Los datos obtenidos indican que la inyección i.p. de Con A en ratones NIH genera una protección parcial insepecífica contra T. gondii cepa RH, la cual aumenta si se aplican 20 µg del mitógeno siete días antes de la confrontación