ABSTRACT
The murine model of actinomycetoma offers the potential of studying many unknown aspects of this infection. In this work, the model was used to investigate the temporal humoral immune response to actinomycetoma agents. Groups of 7- to 9-week-old female BALB/c mice were inoculated in one of the hind footpads with one of four different Nocardia strains. To mimic the constant exposure of infected humans to the virulent soil inhabiting agents, a second injection consisting of live nocardiae in incomplete Freund's adjuvant was administered five months after the first one. Murine serum samples were collected throughout the study and their IgM and IgM titers were determined by ELISA and the Western blot assay. The results obtained indicate that the ELISA titers increased as the infection progressed and this correlated with a greater number of antigen bands being recognized in the blots. Overall, however, the ELISA titers were lower for the N. brasiliensis infected mice than those of the N. asteroides ones. This observation may be indicative of an immunosuppressive state and is worthy of further investigation.
Subject(s)
Disease Models, Animal , Mycetoma/immunology , Nocardia Infections/immunology , Nocardia asteroides , Animals , Antibodies, Bacterial/blood , Antibody Formation , Blotting, Western , Enzyme-Linked Immunosorbent Assay , Female , Immunoglobulin G/blood , Immunoglobulin M/blood , Mice , Mice, Inbred BALB C , Nocardia/immunology , Nocardia asteroides/immunology , Time FactorsABSTRACT
The murine model of actinomycetoma offers the potential of studying many unknown aspects of this infection. In this work, the model was used to investigate the temporal humoral immune response to actinomycetoma agents. Groups of 7- to 9-week-old female BALB/c mice were inoculated in one of the hind footpads with one of four different Nocardia strains. To mimic the constant exposure of infected humans to the virulent soil inhabiting agents, a second injection consisting of live nocardiae in incomplete Freund's adjuvant was administered five months after the first one. Murine serum samples were collected throughout the study and their IgM and IgM titers were determined by ELISA and the Western blot assay. The results obtained indicate that the ELISA titers increased as the infection progressed and this correlated with a greater number of antigen bands being recognized in the blots. Overall, however, the ELISA titers were lower for the N. brasiliensis infected mice than those of the N. asteroides ones. This observation may be indicative of an immunosuppressive state and is worthy of further investigation
Subject(s)
Animals , Female , Mice , Disease Models, Animal , Mycetoma/immunology , Nocardia asteroides , Nocardia Infections/immunology , Antibodies, Bacterial/blood , Antibody Formation , Blotting, Western , Enzyme-Linked Immunosorbent Assay , Immunoglobulin G/blood , Immunoglobulin M/blood , Mice, Inbred BALB C , Nocardia asteroides/immunology , Nocardia/immunology , Time FactorsABSTRACT
Three morphologically different pupal phenotypes (green, striped, brown) were selected from a parent strain of Anopheles albimanus Wiedemann collected from the Suchiate region in the state of Chiapas, Mexico. Significant differences in susceptibility to coindigenous Plasmodium vivax Grassi & Feletti were observed when striped was compared with the parent colony as well as with brown and with green phenotypes. Differences in susceptibility were not significant between the other phenotypes and the parent colony.
Subject(s)
Anopheles/parasitology , Plasmodium vivax/isolation & purification , Animals , Anopheles/classification , Female , Humans , Insect Vectors/parasitology , Malaria, Vivax/transmission , Phenotype , Pupa/parasitology , Species SpecificityABSTRACT
Studies of host selection patterns of Anopheles pseudopunctipennis were conducted in villages in foothills near Tapachula, Mexico. Based on 2 years of collections, 53.8 and 86.1% of all engorged females resting inside houses were found to contain human blood. Estimates of weighted and unweighted human blood indices, including data from outdoor resting collections, varied from 29.5 to 54.7%. Humans and dogs were the more common blood sources for all An. pseudopunctipennis mosquitoes, accounting for 96% of blood meals tested. Results of analyses of host preference through estimates of forage ratios (FRs) indicated that the large numbers of blood meals from humans and dogs were more reflective of host availability than host preference. An FR of less than 1 indicated that, in terms of host availability, proportionately fewer An. pseudopunctipennis females fed on humans than other large animal hosts. In contrast, FRs of 15-20 and 5-7 revealed strong selective biases for horses and pigs as sources of blood meals, respectively. The proportion of outdoor-resting, blood-engorged females containing human blood declined markedly after houses were sprayed with DDT. This response to house spraying is attributed to an excito-repellency effect of DDT.