RESUMEN
The effect of L. acidophilus supplementation to reduce fecal shedding of Cryptosporidium parvum oocysts was compared to L. reuteri using C57BL/6 female mice immunosuppressed by murine leukemia virus (strain LP-BM5) inoculation. After 12 weeks post LP-BM5 inoculation, 15 immunosuppressed mice each were randomly assinged to one of the following treatment groups: historical control (group A), LP-BM5 control (group B), C. parvum (group C), L. reuteri plus C. parvum (group D) or L. acidophilus plus C. parvum (group E). Mice were pre-fed the L. reuteri or L. acidophilus bacteria strains daily for 13 days, challenged with C. parvum oocysts and thereafter fed the specified Lactobacillus regimens daily during the experimental period. Animals supplemented with L. reuteri shed fewer (p<0.05) oocysts on day-7 post C. parvum challenge compared to controls. Mice supplemented with L. acidophilus also shed fewer (p<0.05) oocysts on days 7 and 14 post-challenge compared to controls. Overall, Lactobacillus supplementation reduced C. parvum shedding in the feces but failed to suppress the production of T-helper type 2 cytokines [interleukin-4 (IL-4), IL-8)] which are associated with immunosuppression. Additionally, Lactobacillus supplementation did not restore T-helper type 1 cytokines (interleukin-2 (IL-2) and gamma interferon (IFN-gamma), which are required for recovery from parasitic infections. Altered T-helper types 1 and 2 cytokine production as a consequence of immunodysfunction permitted the development of persistent cryptosporidiosis while mice with intact immune system were refractory to infection with C. parvum. Reduction in shedding of oocysts observed in the Lactobacillus supplemented mice during deminished IL-2 and IFN-gamma production may be mediated by factors released into the intestinal lumen by the Lactobacillus and possibly other host cellular mechanisms. These observations suggest that L. reuteri or L. acidophilus can reduce C. parvum parasite burdens in the intestinal epithelium during cryptosporidiosis and may serve potential benefits as probiotics for host resistance to intestinal parasitic infections. L. acidophilus was more efficacious in reducing fecal shedding than L. reuteri and therefore may also have implication in the therapy of cryptosporidiosis during immunosuppressive states including human AIDS.
Asunto(s)
Criptosporidiosis/terapia , Cryptosporidium parvum/parasitología , Lactobacillus , Ratones Endogámicos C57BL/parasitología , Síndrome de Inmunodeficiencia Adquirida del Murino/complicaciones , Probióticos/uso terapéutico , Infecciones Oportunistas Relacionadas con el SIDA/terapia , Animales , Peso Corporal , Criptosporidiosis/complicaciones , Cryptosporidium parvum/crecimiento & desarrollo , Ingestión de Líquidos , Ingestión de Alimentos , Heces/parasitología , Femenino , Intestinos/parasitología , Lactobacillus acidophilus , Virus de la Leucemia Murina , Ratones , Ratones Endogámicos C57BL/virología , Síndrome de Inmunodeficiencia Adquirida del Murino/inmunología , Síndrome de Inmunodeficiencia Adquirida del Murino/metabolismo , Tamaño de los Órganos , Probióticos/farmacología , Bazo/anatomía & histología , Esparcimiento de VirusRESUMEN
Efficacy of Lactobacillus reuteri as a probiotic for the control of Cryptosporidium parvum infection was evaluated in C57BL/6 female mice that were immunosuppressed by intraperitoneal inoculation with the LP-BM5 leukemia virus. Four months after inoculation, mice developed lymphadenopathy, splenomegaly, and susceptibility to C. parvum infection. After daily prefeeding with L. reuteri (10(8) cfu/day) for 10 days, mice were challenged with 6.5 x 10(6) C. parvum oocysts and fed L. reuteri during the entire study. Mice supplemented with L. reuteri and challenged with C. parvum cleared parasite loads from the gut epithelium. However, unsupplemented animals developed persistent cryptosporidiosis and shed high levels of oocysts in the feces. L. reuteri feeding increased its colonization of the intestinal tract, which was inversely related to the fecal shedding of oocysts. These findings suggest that L. reuteri may help prevent C. parvum infection in immunodeficient subjects.
Asunto(s)
Infecciones Oportunistas Relacionadas con el SIDA/prevención & control , Antibiosis , Criptosporidiosis/prevención & control , Cryptosporidium parvum/crecimiento & desarrollo , Lactobacillus/fisiología , Síndrome de Inmunodeficiencia Adquirida del Murino/complicaciones , Infecciones Oportunistas Relacionadas con el SIDA/parasitología , Animales , Criptosporidiosis/parasitología , Cryptosporidium parvum/aislamiento & purificación , Ingestión de Líquidos , Ingestión de Alimentos , Heces/microbiología , Heces/parasitología , Mucosa Intestinal/parasitología , RatonesRESUMEN
The LP-BM5 murine leukemia virus causes acquired immunodeficiency syndrome in C57BL/6J mice (MAIDS), similar to that of AIDS in humans. The objective of this study was to determine the effect of LP-BM5 viral infection on cellular activation and membrane integrity of splenocytes. Oxidative burst in splenocytes in response to exposure to PMA (20 microg/ml) was significantly higher (p<.02) in infected than in control mice at two weeks post-infection using luminol-enhanced chemiluminescence. By 13 weeks post-infection superoxide anion production in infected mice was significantly lower when compared to controls coinciding with decreased proliferative response to mitogens. The extent of cell membrane damage as indicated by lactic dehydrogenase (LDH) activity in serum was significantly higher in infected than in control mice (p<.001). The results from this study suggests that LP-BM5 virus causes an initial stimulation of cellular activity followed by a decreased cell activation characterized by decreased proliferation of splenocytes and decreased oxygen radical production. Decreased cell membrane integrity indicated by increased LDH activity may partly be responsible for these changes.
Asunto(s)
L-Lactato Deshidrogenasa/biosíntesis , Virus de la Leucemia Murina/fisiología , Especies Reactivas de Oxígeno/metabolismo , Bazo/enzimología , Bazo/metabolismo , Animales , Concanavalina A/farmacología , Activación Enzimática , Femenino , Activación de Linfocitos , Ratones , Ratones Endogámicos C57BL , Bazo/citología , Bazo/inmunologíaRESUMEN
The effects of inoculation of LP-BM5 murine leukemia retrovirus and chronic ethanol (5% v/v) ingestion on immunomodulation and Cryptosporidium parvum infection in C57BL/6 female mice were evaluated. The intestinal mucosae of retrovirally immunosuppressed animals were heavily colonized by Cryptosporidium parasites, and oocysts shedding in the feces persisted throughout the duration of the study. Mortality was exacerbated by murine retrovirus infection alone and exacerbated with concomitant chronic alcohol feeding (42.8 and 69.4%). Chronic ethanol ingestion decreased production of interferon-gamma and soluble interleukin-2 receptor released in supernatants of splenocytes when stimulated with concanavalin A, compared with the control group. Decreased production of interferon-gamma and interleukin-2 receptor was further exacerbated due to retrovirus infection. Tumor necrosis factor production by splenocytes stimulated with lipopolysaccharide, however, was significantly increased because of retrovirus infection. LP-BM5 retrovirus infection alone as well as with concomitant ethanol feeding altered cytokine production, which might have led to immunodeficiency. These changes may help explain the enhanced persistence of Cryptosporidiosis.
Asunto(s)
Alcoholismo/inmunología , Cryptosporidium parvum/inmunología , Citocinas/biosíntesis , Síndrome de Inmunodeficiencia Adquirida del Murino/inmunología , Animales , Heces/microbiología , Femenino , Interferón-alfa/biosíntesis , Interleucina-2/biosíntesis , Ratones , Ratones Endogámicos C57BL , Síndrome de Inmunodeficiencia Adquirida del Murino/parasitología , Recuento de Huevos de Parásitos , Factor de Necrosis Tumoral alfa/biosíntesisRESUMEN
Significant immunological changes occur following LP-BM5 murine leukemia retrovirus infection as well as chronic alcohol consumption. Retrovirus infection which has proceeded to murine AIDS permitted persistent Cryptosporidium infection, while non-retrovirus infected mice were resistant. Dietary alcohol provided until the day before parasite challenge did not affect resistance in controls, but increased the numbers of oocysts in the feces of retrovirus suppressed mice. Mortality was significant in retrovirus infected mice, and exacerbated slightly by dietary ethanol, while all controls survived parasite challenge. The retrovirus infected mice had greatly reduced numbers of intestinal CD4+ T helper cells and IgA+ B cells, which may explain their loss of intestinal resistance. Clearly, the severely immunosuppressed animals with murine AIDS were more sensitive to alcohol consumption than uninfected controls. This suggests that alcohol can synergize with murine retrovirus infection to exacerbate loss of resistance to an opportunistic pathogen common in human AIDS patients.
Asunto(s)
Criptosporidiosis/inmunología , Etanol/farmacología , Inmunidad Innata/efectos de los fármacos , Síndrome de Inmunodeficiencia Adquirida del Murino/complicaciones , Animales , Criptosporidiosis/complicaciones , Criptosporidiosis/parasitología , Cryptosporidium/crecimiento & desarrollo , Cryptosporidium/aislamiento & purificación , Heces/parasitología , Femenino , Intestinos/parasitología , Ratones , Ratones Endogámicos C57BL , Síndrome de Inmunodeficiencia Adquirida del Murino/inmunología , RetroviridaeRESUMEN
Eight groups of 5 rats were fed 8 differing liquid diets with and without ethanol, cod liver oil and/or increased levels of vitamin E. Hepatic levels of vitamins A and E were determined following the 28-day feeding time. Ethanol consumption decreased the levels of hepatic vitamin E (p less than 0.05), vitamin A (p less than 0.05) and the ratio of vitamin A/E (p less than 0.05). Hepatic levels of vitamins A and E were unaffected in rats fed cod liver oil. Supplementation of the normal dietary level of 30 IU of vitamin E per kg diet, with an additional 142 IU alpha tocopherol/kg diet, restored hepatic concentrations of vitamin E to normal levels in alcohol-fed rats. The hepatic levels of vitamin A in rats fed ethanol diets supplemented with vitamin E were less than that of control rats but were 4.3 times greater than that of rats on ethanol diets unsupplemented with vitamin E. However, the vitamin A and E ratio was equal to normal in this group of rats. The vitamin A/E ratio was reduced in liver of rats fed non-alcoholic diets supplemented with vitamin E due to increased levels of hepatic vitamin E. Additionally, rats fed cod liver oil diets containing ethanol also indicated decreased hepatic vitamin A and E levels. However, these levels were greater than that of rats fed only alcoholic diets suggesting that these vitamins are replaced by the vitamin A and E content in the cod liver oil.(ABSTRACT TRUNCATED AT 250 WORDS)