Search this site:

Research Grants Approved :

Presentation of the Successful Projects for the Period 2001 - 2003

Nine proposals were selected for participation in the NeTropica project 2001-2003. Priority was given to scientists who have previously participated as students or tutors in the various Graduate Programs in Biomedical Sciences in Central America. Research teams were selected on the basis of scientific and academic achievement, demonstrated leadership, and existing infrastructure.  

Abstracts of the nine selected research projects:  

PROJECT 1
Effects of tissue damage toxins from the venom of the snake Bothrops asper on infection of muscle tissue by Staphylococcus aureus  

PROJECT 2
Antimicrobial activity of cationic peptides derived from tropical snake venom 

PROJECT 3
Rotavirus gastrointestinal infection in Nicaraguan, Panamanian and Honduras children  

PROJECT 4
Clinical Epidemiological and Seroepidemiological aspects of Shigellosis  

PROJECT 5 
Molecular typing of mycobacterium tuberculosis in Honduras and Guatemala  

PROJECT 6
Cytomegalovirus genotypes circulating in Honduras and Costa Rica in different patient populations.  

PROJECT 7
Morphometric and genetic characterization for sylvatic and domestic Triatoma dimidiata populations in Guatemala, Honduras and Nicaragua to understand the migration and reinfestation pattern of the species. 

PROJECT 8
Preparation and characterization of monoclonal antibodies against a Trypanosoma rangeli Sialidase  

PROJECT 9 
Trypanosoma Cruzi minicircle DNA detection among cardiac patients from Guatemala endemic area hospitals.

Research contracts were written for the Responsible Investigator and the Principal Investigator(s) for each of the nine research projects. Signed copies of the contracts in Spanish and English are kept on file at the office of NeTropica ; copies were also sent to the Karolinska Institute in Sweden.

PROJECT 1

Effects of tissue damage toxins from the venom of the snake Bothrops asper on infection of muscle tissue by Staphylococcus aureus .  

Comparative study on the biochemistry, toxicology and immunology of snake venom in Central America. This project is a comparative analysis of the biochemistry and toxicology of the venom's of three species of snakes common in Central America, as an initial step in understanding the interspecies variability of snake venom's in this region. The venom's of Bothrops asper, Crotalus durissus and Atropoides nummifer will be studied, as they constitute three of the most important snakes from a medical point of view in Central America. The second stage in the project will be a comparative toxicological and pharmacological characterization of venoms from Guatemala and Costa Rica. The third stage in the project will be an evaluation of the ability of anti-venoms produced in México and Costa Rica to neutralize the most relevant toxic constituents of Guatemalan and Costa Rican snake venoms. This part of the project will provide the information required to decide if there is a need to design novel immunization mixtures to produce anti-venoms of higher efficiency than those already available for the neutralization of Guatemalan snake venoms. The methodologies and conclusions of this project will be the basis of a more complete and comprehensive characterization of snake venoms from Central America.    

PROJECT 2

Antimicrobial activity of Cationic Peptides derived from tropical snake venom.

Previous studies have shown that myotoxic phospholipases A2 (PLA2s) present in the venom of the snake Bothrops asper from Costa Rica are capable of killing bacteria in vitro. In this project, we propose to further characterize the bactericidal activity and anti-microbial spectrum of venom myotoxins.

PROJECT 4

Clinical Epidemiological and Seroepidemiological aspects of Shigellosis

Shigellosis plays an important role in rates of morbidity and mortality in developing countries and is still an important disease in industrialized nations. Shigella is prevalent in overcrowded areas with poor sanitation. Transmission of Shigella is person-to-person by the fecal oral route. Shigellosis or bacillary dysentery is mainly a disease of young children, but all age groups can be affected. Symptoms of the disease include acute, severe gastrointestinal infection with fever, tenesmus, abdominal cramps and in particular frequent small, mucous depositions containing visible blood and leukocytes. As Shigella is prevalent in Costa Rica, particularly among poor, urban groups, we wish to continue our investigation of the epidemiological and clinical aspects of shigellosis in Costa Rica; specifically, its prevalence and seroprevalence, as well as to improve diagnostic methods. Our future goal is to study shigellosis in other Central American countries where the disease is common, but no studies are presently being conducted, due to the lack of laboratory facilities and researchers trained to work with enteric bacteria. 

PROJECT 5

Molecular typing of Mycobacterium tuberculosis strains from Honduras and Guatemala.  

This project is a comparative molecular analysis using DNA fingerprinting of Mycobacterium tuberculosis a genetic technique. Isolates will be obtained from tuberculosis patients from Honduras and Guatemala. Restriction Fragment Length Polymorphism (RFLP) with the insertion sequence IS 6110 will be used to compare all the fingerprinting of M. tuberculosis isolated. Additionally, this method will allow the identification of the specific clone circulating among tuberculosis patients. As an initial stage isolate strains from different kind of samples will be used. The second stage of the project will be the standardization of RFLP method and the molecular characterization of M. tuberculosis strains isolated from both countries. The last stage will be the analysis of fingerprints using Gel Compar system. Such data will provide information about the characterization of M. tuberculosis from Honduras and Guatemala or both. Other uses include the identification of outbreaks, the tracing noscomial infections and the investigations of ongoing spread of infections in a certain population such as drug-susceptible and drug-resistant patients.

PROJECT 6

Cytomegalovirus genotypes circulating in Honduras and Costa Rica in different patient populations.

The general objective of this proposal is to determine the gB genotypes circulating in Costa Rica and Honduras at the present time and compare them with genotypes of viruses isolated fifteen years ago in Costa Rican newborns. The specific objectives are to determine if there is a different distribution of genotypes in different patient populations and compare them with circulating genotypes of fifteen years ago. The glycoprotein B (gB) of the cytomegalovirus is considered to be a multifunctional envelope component responsible for the virion entry, cell to cell spread and syncytium formation, and it is also the major target for neutralizing antibodies. Sera samples will be used from a sera bank of alcoholics, neonatal patients, AIDS patients and blood donors. Amplified products by PCR will be analyzed by restriction fragment length polymorphism followed by electrophoresis and staining by ethidium bromide. This will allow the CMV isolates to be classified into four gB genotypes. To group specimens into further subtypes a single-stranded conformation polymorphism and heteroduplex mobility analysis will be done. Sequencing of selected specimens will also be performed. It is very important to determine the CMV genotypes circulating in Costa Rica and Honduras in the different populations to be able to implement more effective procedures for treatment and patient care.

PROJECT 7

Morphometric and genetic characterization for sylvatic and domestic Triatoma dimidiata populations in Guatemala, Honduras and Nicaragua to understand the migration and reinfestation pattern of the species.

This is a control-oriented study with the aim of obtaining information about the re-infestation pattern of T. dimidiata , T. nitida and Rhodnius prolixus in areas of Guatemala, Honduras and Nicaragua where CHAGAS disease is endemic. To support the Central American initiative on the control of CHAGAS disease vectors, further research is required to understand the re-infestation patterns of the main vectors. T. dimidiata, for example, is found in both urban and rural areas, and is one of the most important vectors of CHAGAS disease. In order to develop strategies to avoid re-infestation of treated houses, its migration pattern must be clarified. T. nitida is also among the important vectors in Guatemala and Honduras and nothing is known about the infestation pattern of this species. Rhodnius prolixus is the main vector in Honduras and is related to house construction; in Guatemala, R. prolixus is among the main vectors.

PROJECT 8

Preparation and Characterisation of Monoclonal Antibodies Against a Trypanosoma rangeli Sialidase

Trypanosoma rangeli is a human parasite closely related to T. cruzi, the etiologic agent of Chagas’ disease. Because of their common vectors and hosts, the comparative biochemical and immunological properties of the pathogen T. cruzi and apparently non-pathogenic T. rangeli are of significant interest. Experimental studies have established that these haemoflagelates share common and specific antigenic characteristics.; The identification and characterization of T. rangeli components able to elicit an immune response and the degree of similarity with those found in T. cruzi have until now been overlooked. Appropriate studies could help in the correct parasite identification, which is imperative if appropriate therapeutic measures are to be implemented. The study of the composition and characteristics of T. rangeli is likely to contribute to our understanding of the biochemical and regulatory changes which the parasite adopts in particular biological conditions. Such information could help in the understanding of important parasite-host interactions such as the pathogenic and harmless infections observed in the vector and mammalian respectively.

PROJECT 9

Trypanosoma Cruzi minicircle DNA detection among cardiac patients from Guatemala endemic area hospitals.

American trypanosomiasis, also called Chagas’ disease, is considered by the World Health Organization (WHO) to be one of the major health problems in Central and South America. An estimated 18 million persons are infected, and Chagas’ disease is a leading cause of cardiomyopathy and sudden cardiac death. Persons infected with T. cruzi have life long parasitemia. Most, however, are unaware that they are infected, but approximately 30% of them eventually develop the clinical manifestation of chronic Chagas´ disease, which is characterized by irreversible cardiac damage. The disease is fatal in 2-3% of cases involving young children who do not receive anti-parasitic treatment during the acute phase of the disease, thus early detection is very important. The main objective of this study is detecting T. cruzi infection among 3,500 school-aged children from endemic areas of Guatemala and to compare the efficacy of 4 different serologic techniques used for diagnosis.

Best viewed with Internet Explorer 6.0 800x600 pixels