The Characterization of Cardiac Explants Reveals Unique Fibrosis Patterns and a Predominance of CD8+ T Cell Subpopulations in Patients with Chronic Chagas Cardiomyopathy.

AIM: The present study aimed to characterize the histopathological findings and the phenotype of inflammatory cells in the myocardial tissue of patients with end-stage heart failure (ESHF) secondary to CCC in comparison with ESHF secondary to non-Chagas cardiomyopathies (NCC). METHODS: A total of 32 explanted hearts were collected from transplanted patients between 2014 and 2017. Of these, 21 were classified as CCC and 11 as other NCC. A macroscopic analysis followed by a microscopic analysis were performed. Finally, the phenotypes of the inflammatory infiltrates were characterized using flow cytometry. RESULTS: Microscopic analysis revealed more extensive fibrotic involvement in patients with CCC, with more frequent foci of fibrosis, collagen deposits, and degeneration of myocardial fibers, in addition to identifying foci of inflammatory infiltrate of greater magnitude. Finally, cell phenotyping identified more memory T cells, mainly CD8+CD45RO+ T cells, and fewer transitioning T cells (CD45RA+/CD45RO+) in patients with CCC compared with the NCC group. CONCLUSIONS: CCC represents a unique form of myocardial involvement characterized by abundant inflammatory infiltrates, severe interstitial fibrosis, extensive collagen deposits, and marked cardiomyocyte degeneration. The structural myocardial changes observed in late-stage Chagas cardiomyopathy appear to be closely related to the presence of cardiac fibrosis and the colocalization of collagen fibers and inflammatory cells, a finding that serves as a basis for the generation of new hypotheses aimed at better understanding the role of inflammation and fibrogenesis in the progression of CCC. Finally, the predominance of memory T cells in CCC compared with NCC hearts highlights the critical role of the parasite-specific lymphocytic response in the course of the infection.

Metabolomic Profiling of End-Stage Heart Failure Secondary to Chronic Chagas Cardiomyopathy.

Chronic Chagas cardiomyopathy (CCC) is the most frequent and severe clinical form of chronic Chagas disease, representing one of the leading causes of morbidity and mortality in Latin America, and a growing global public health problem. There is currently no approved treatment for CCC; however, omics technologies have enabled significant progress to be made in the search for new therapeutic targets. The metabolic alterations associated with pathogenic mechanisms of CCC and their relationship to cellular and immunopathogenic processes in cardiac tissue remain largely unknown. This exploratory study aimed to evaluate the potential underlying pathogenic mechanisms in the failing myocardium of patients with end-stage heart failure (ESHF) secondary to CCC by applying an untargeted metabolomic profiling approach. Cardiac tissue samples from the left ventricle of patients with ESHF of CCC etiology (n = 7) and healthy donors (n = 7) were analyzed using liquid chromatography-mass spectrometry. Metabolite profiles showed altered branched-chain amino acid and acylcarnitine levels, decreased fatty acid uptake and oxidation, increased activity of the pentose phosphate pathway, dysregulation of the TCA cycle, and alterations in critical cellular antioxidant systems. These findings suggest processes of energy deficit, alterations in substrate availability, and enhanced production of reactive oxygen species in the affected myocardium. This profile potentially contributes to the development and maintenance of a chronic inflammatory state that leads to progression and severity of CCC. Further studies involving larger sample sizes and comparisons with heart failure patients without CCC are needed to validate these results, opening an avenue to investigate new therapeutic approaches for the treatment and prevention of progression of this unique and severe cardiomyopathy.

A Genome-Wide Association Study Identifies Novel Susceptibility loci in Chronic Chagas Cardiomyopathy.

BACKGROUND: Chagas disease is an infectious disease caused by the parasite Trypanosoma cruzi and is endemic from Latin American countries. The goal of our study was to identify novel genetic loci associated with chronic Chagas cardiomyopathy development in Chagas disease patients from different Latin American populations. METHODS: We performed a cross-sectional, nested case-control study including 3 sample collections from Colombia, Argentina, and Bolivia. Samples were genotyped to conduct a genome-wide association study (GWAS). These results were meta-analyzed with summary statistic data from Brazil, gathering a total of 3413 Chagas disease patients. To identify the functional impact of the associated variant and its proxies, we performed an in silico analysis of this region. RESULTS: The meta-analysis revealed a novel genome-wide statistically significant association with chronic Chagas cardiomyopathy development in rs2458298 (OR = 0.90, 95%CI = 0.87-0.94, P-value = 3.27 × 10-08), nearby the SAC3D1 gene. In addition, further in silico analyses displayed functional relationships between the associated variant and the SNX15, BAFT2, and FERMT3 genes, related to cardiovascular traits. CONCLUSIONS: Our findings support the role of the host genetic factors in the susceptibility to the development of the chronic cardiac form of this neglected disease.

Lack of Association of IL6 polymorphism with the susceptibility to Chagas disease in Latin American populations.

The aim of the present study was to analyze IL6 rs1800795 genetic variant in the susceptibility to Trypanosoma cruzi infection and in the development of chronic Chagas cardiomyopathy (CCC), in five independent Latin American cohorts. A total of 3,087 individuals from Latin American countries (Argentina, Bolivia, Peru, and two cohorts from Colombia) were studied. In all cohorts, patients were classified as seropositive for T. cruzi antigens (n= 1,963) and seronegative (n= 1,124). Based on clinical evaluation, the seropositive patients, were classified as CCC (n= 900) and asymptomatic (n= 1,063). No statistically significant differences in the frequency of IL6 rs1800795 between seropositive and seronegative, or between CCC and asymptomatic patients, were found. Furthermore, after the meta-analysis no statistically significant differences were observed. Our results do not support a contribution of IL6 rs1800795 genetic variant in the susceptibility to the infection and the development of chronic Chagas cardiomyopathy in the studied populations.

Genetic polymorphisms of IL17A associated with Chagas disease: results from a meta-analysis in Latin American populations.

Genetic factors and the immunologic response have been suggested to determine the susceptibility against the infection and the outcome of Chagas disease. In the present study, we analysed three IL17A genetic variants (rs4711998, rs8193036 and rs2275913) regarding the predisposition to Trypanosoma cruzi infection and the development of chronic Chagas cardiomyopathy (CCC) in different Latin American populations. A total of 2,967 individuals from Colombia, Argentina, Bolivia and Brazil, were included in this study. The individuals were classified as seronegative and seropositive for T. cruzi antigens, and this last group were divided into asymptomatic and CCC. For T. cruzi infection susceptibility, the IL17A rs2275913*A showed a significant association in a fixed-effect meta-analysis after a Bonferroni correction (P = 0.016, OR = 1.21, 95%CI = 1.06-1.41). No evidence of association was detected when comparing CCC vs. asymptomatic patients. However, when CCC were compared with seronegative individuals, it showed a nominal association in the meta-analysis (P = 0.040, OR = 1.20, 95%CI = 1.01-1.45). For the IL17A rs4711998 and rs8193036, no association was observed. In conclusion, our results suggest that IL17A rs2275913 plays an important role in the susceptibility to T. cruzi infection and could also be implicated in the development of chronic cardiomyopathy in the studied Latin American population.

Efficacy of the Benznidazole+Posaconazole combination therapy in parasitemia reduction: An experimental murine model of acute Chagas.

INTRODUCTION: Benznidazole (BZL) and Nifurtimox (NFX) are the pharmacological treatment for acute phase Chagas Disease (CD); however, therapy resistance and residual mortality development remain important unresolved issues. Posaconazole (POS) has shown a trypanocidal effect in vivo and in vitro. Thus, this study aimed at comparing the T. Cruzi parasitic load-reducing effect of the combination of BZL+POS against that of monotherapy with either, during acute phase CD, in an experimental murine model. METHODS: Nineteen Wistar rats were randomly allocated to four groups and inoculated with the trypomastigotes of T. cruzi strain´s JChVcl1. The rats were administered anti-parasites from day 20-29 post-infection. The Pizzi and Brener method was used for parasitemia measurement. Longitudinal data analysis for the continuous outcome of repeated measures was performed using parasitemia as the outcome measured at days 20, 22, 24, 27, and 29 post-infection. RESULTS: All four groups had similar parasitic loads (p=0.143) prior to therapy initiation. Among the three treatment groups, the BZL+POS (n=5) group showed the highest mean parasitic load reduction (p=0.000) compared with the control group. Likewise, the BZL+POS group rats showed an earlier therapeutic effect and were the only ones without parasites in their myocardial samples. CONCLUSIONS: Treatment of acute phase CD with BZL+POS was more efficacious at parasitemia and myocardial injury reduction, compared with monotherapy with either.

Efficacy of the Benznidazole+Posaconazole combination therapy in parasitemia reduction: An experimental murine model of acute Chagas

Abstract INTRODUCTION: Benznidazole (BZL) and Nifurtimox (NFX) are the pharmacological treatment for acute phase Chagas Disease (CD); however, therapy resistance and residual mortality development remain important unresolved issues. Posaconazole (POS) has shown a trypanocidal effect in vivo and in vitro. Thus, this study aimed at comparing the T. Cruzi parasitic load-reducing effect of the combination of BZL+POS against that of monotherapy with either, during acute phase CD, in an experimental murine model. METHODS Nineteen Wistar rats were randomly allocated to four groups and inoculated with the trypomastigotes of T. cruzi strain´s JChVcl1. The rats were administered anti-parasites from day 20-29 post-infection. The Pizzi and Brener method was used for parasitemia measurement. Longitudinal data analysis for the continuous outcome of repeated measures was performed using parasitemia as the outcome measured at days 20, 22, 24, 27, and 29 post-infection. RESULTS All four groups had similar parasitic loads (p=0.143) prior to therapy initiation. Among the three treatment groups, the BZL+POS (n=5) group showed the highest mean parasitic load reduction (p=0.000) compared with the control group. Likewise, the BZL+POS group rats showed an earlier therapeutic effect and were the only ones without parasites in their myocardial samples. CONCLUSIONS: Treatment of acute phase CD with BZL+POS was more efficacious at parasitemia and myocardial injury reduction, compared with monotherapy with either.

Association of IL18 genetic polymorphisms with Chagas disease in Latin American populations.

Host genetic factors have been suggested to play an important role in the susceptibility to Chagas disease. Given the influence of interleukin 18 (IL-18) in the development of the disease, in the present study, we analyzed three IL18 genetic variants (rs2043055, rs1946518, rs360719) regarding the predisposition to Trypanosoma cruzi infection and the development of chronic Chagas cardiomyopathy (CCC), in different Latin America populations. Genetic data of 3,608 patients from Colombia, Bolivia, Argentina, and Brazil were meta-analyzed to validate previous findings with increased statistical power. Seropositive and seronegative individuals were compared for T. cruzi infection susceptibility. In the Colombian cohort, the allelic frequencies of the three variants showed a significant association, with adjustment for sex and age, and also after applying multiple testing adjustments. Among the Colombian and Argentinean cohorts, rs360719 showed a significant genetic effect in a fixed-effects meta-analysis after a Bonferroni correction (OR: 0.76, CI: 0.66-0.89, P = 0.001). For CCC, the rs2043055 showed an association with protection from cardiomyopathy in the Colombian cohort (OR: 0.79, CI: 0.64-0.99, P = 0.037), with adjustment for sex and age, and after applying multiple testing adjustments. The meta-analysis of the CCC vs. asymptomatic patients from the four cohorts showed no evidence of association. In conclusion, our results validated the association found previously in the Colombian cohort suggesting that IL18 rs360719 plays an important role in the susceptibility to T. cruzi infection and no evidence of association was found between the IL18 genetic variants and CCC in the Latin American population studied.

Association study between CCR2-CCR5 genes polymorphisms and chronic Chagas heart disease in Wichi and in admixed populations from Argentina.

Several studies have proposed different genetic markers of susceptibility to develop chronic Chagas cardiomyopathy (CCC). Many genes may be involved, each one making a small contribution. For this reason, an appropriate approach for this problematic is to study a large number of single nucleotide polymorphisms (SNPs) in individuals sharing a genetic background. Our aim was to analyze two CCR2 and seven CCR5 SNPs and their association to CCC in Argentina. A case-control study was carried out in 480 T. cruzi seropositive adults from Argentinean Gran Chaco endemic region (Wichi and Creole) and patients from Buenos Aires health centres. They were classified according to the Consensus on Chagas-Mazza Disease as non-demonstrated (non-DC group) or demonstrated (DC group) cardiomyopathy, i.e. asymptomatic or with CCC patients, respectively. Since, after allelic analysis, 2 out of 9 studied SNPs did not fit Hardy-Weinberg equilibrium in the unaffected non-DC group from Wichi patients, we analyzed them as a separate population. Only rs1800024T and rs41469351T in CCR5 gene showed significant differences within non-Wichi population (Creole + patients from Buenos Aires centres), being the former associated to protection, and the latter to risk of CCC. No evidence of association was observed between any of the analyzed CCR2-CCR5 gene polymorphisms and the development of CCC; however, the HHE haplotype was associated with protection in Wichi population. Our findings support the hypothesis that CCR2-CCR5 genes and their haplotypes are associated with CCC; however, depending on the population studied, different associations can be found. Therefore, the evolutionary context, in which the genes or haplotypes are associated with diseases, acquires special relevance.

Comprehensive analysis of three TYK2 gene variants in the susceptibility to Chagas disease infection and cardiomyopathy.

Tyrosine kinase 2 (TYK2) is a member of the Janus kinases family implicated in the signal transduction of type I interferons and several interleukins. It has been described that genetic mutations within TYK2 lead to multiple deleterious effects in the immune response. In this work, we have analyzed three functional independent variants from the frequency spectrum on the TYK2 gene (common and low-frequency variants) suggested to reduce the function of the gene in mediating cytokine signaling and the susceptibility to infections by Trypanosoma cruzi and/or the development of Chagas cardiomyopathy in the Colombian population. A total of 1,323 individuals from a Colombian endemic region for Chagas disease were enrolled in the study. They were classified as seronegative (n = 445), seropositive asymptomatic (n = 336), and chronic Chagas Cardiomyopathy subjects (n = 542). DNA samples were genotyped using TaqMan probes. Our results showed no statistically significant differences between the allelic frequencies of the three analyzed variants when seropositive and seronegative individuals were compared, therefore these variants were not associated with susceptibility to Chagas disease. Moreover, when Chagas cardiomyopathy patients were compared to asymptomatic patients, no significant associations were found. Previous reports highlighted the association of this gene in immune-related disorders under an autoimmunity context, but not predisposing patients to infectious diseases, which is consistent with our findings. Therefore, according to our results, TYK2 gene variants do not seem to play an important role in Chagas disease susceptibility and/or chronic Chagas cardiomyopathy.

Evaluation of VDR gene polymorphisms in Trypanosoma cruzi infection and chronic Chagasic cardiomyopathy.

Vitamin D is an important modulator of the immune response. It acts over several immune cell types where the Vitamin D receptor (VDR) is expressed. Due to the high relevance of this signaling pathway, several studies have investigated the possible influence of genes involved in the metabolism of Vitamin D and its receptor in different human diseases. Here, we analyzed whether four single-nucleotide polymorphisms of the VDR gene (rs731236, rs7975232, rs1544410 and rs2228570) are involved in the susceptibility to infection by Trypanosoma cruzi and/or to chronic Chagas cardiomyopathy (CCC) in a Colombian endemic population for this parasite. Our results showed that the rs2228570*A allele is associated with CCC development (P = 4.46E-03, OR = 1.51). In summary, the data presented in this report suggest that variation within the VDR gene may affect the immune response against T. cruzi, increasing the probability of cardiac complications in infected individuals.

IL18 Gene Variants Influence the Susceptibility to Chagas Disease.

Chagas disease is a parasitic disorder caused by the infection with the flagellated protozoan Trypanosoma cruzi. According to the World Health Organization, more than six million people are currently infected in endemic regions. Genetic factors have been proposed to influence predisposition to infection and development of severe clinical phenotypes like chronic Chagas cardiomyopathy (CCC). Interleukin 18 (IL18) encodes a proinflammatory cytokine that has been proposed to be involved in controlling T. cruzi infection. In this study, we analyzed the possible role of six IL18 gene variants (rs5744258, rs360722, rs2043055, rs187238, rs1946518 and rs360719), which cover most of the variation within the locus, in the susceptibility to infection by T. cruzi and/or CCC. In total, 1,171 individuals from a Colombian region endemic for Chagas disease, classified as seronegative (n = 595), seropositive asymptomatic (n = 175) and CCC (n = 401), were genotyped using TaqMan probes. Significant associations with T. cruzi infection were observed when comparing seronegative and seropositive individuals for rs187238 (P = 2.18E-03, OR = 0.77), rs360719 (P = 1.49E-03, OR = 0.76), rs2043055 (P = 2.52E-03, OR = 1.29), and rs1946518 (P = 0.0162, OR = 1.22). However, dependence analyses suggested that the association was mainly driven by the polymorphism rs360719. This variant is located within the promoter region of the IL18 gene, and it has been described that it creates a binding site for the transcription factor OCT-1 affecting IL-18 expression levels. In addition, no evidence of association was observed between any of the analyzed IL18 gene polymorphisms and the development of CCC. In summary, our data suggest that genetic variation within the promoter region of IL18 is directly involved in the susceptibility to infection by T. cruzi, which provides novel insight into disease pathophysiology and adds new perspectives to achieve a more effective disease control.

Laboratory genetic-based reference values for cholinesterase activity in a Colombian population: A step forward in personalized diagnostics.

INTRODUCTION: The determination of cholinesterase (ChE) activity has been commonly applied in the biomonitoring of exposure to organophosphate and carbamate pesticides. However, ChE activity is influenced by genetic factors. Integrating genotype and phenotype information in clinical laboratory tests would increase the accuracy of the reference values in well-defined populations. OBJECTIVE: To establish genetic-based reference values for acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activity in a Colombian population. MATERIALS AND METHODS: A total of 397 healthy adults from Bucaramanga were included in the study. AChE and BChE activities were measured in blood samples by potentiometry and spectrophotometry, respectively. Genotyping for ACHE rs17880573 and BCHE rs1803274 was performed using the TaqMan allelic discrimination assay. The statistical analyses to obtain the reference values were performed with the MedCalc® software. RESULTS: Allele frequencies were 10.58% for rs17880573 A and 8.82% for rs1803274 A. People with genotypes rs1803274 AA and AG showed a reduction of 20.69% and 10.92% respectively in mean BChE activity compared to people with genotype GG. No significant differences were identified in AChE activity between rs17880573 alleles or genotypes. In the overall sample, the corresponding reference values were as follows: for AChE activity, 0.62-0.98 D pH/h and for BChE activity, 4796.3-10321.1 U/L for people carrying the allele rs1803274A and 5768.2-11180.4 U/L for people carrying the genotype rs1803274 GG. CONCLUSION: We strongly recommend using these genetic-based reference values for ChE enzymes in our well-defined population in daily clinical practice.

Laboratory genetic-based reference values for cholinesterase activity in a Colombian population: A step forward in personalized diagnostics / Valores de referencia basados en el contexto genético de la actividad enzimática de la colinesterasa en una población colombiana: un paso hacia el diagnóstico personalizado

Introduction: The determination of cholinesterase (ChE) activity has been commonly applied in the biomonitoring of exposure to organophosphate and carbamate pesticides. However, ChE activity is influenced by genetic factors. Integrating genotype and phenotype information in clinical laboratory tests would increase the accuracy of the reference values in well-defined populations. Objective: To establish genetic-based reference values for acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activity in a Colombian population. Materials and methods: A total of 397 healthy adults from Bucaramanga were included in the study. AChE and BChE activities were measured in blood samples by potentiometry and spectrophotometry, respectively. Genotyping for ACHE rs17880573 and BCHE rs1803274 was performed using the TaqMan allelic discrimination assay. The statistical analyses to obtain the reference values were performed with the MedCalc® software. Results: Allele frequencies were 10.58% for rs17880573 A and 8.82% for rs1803274 A. People with genotypes rs1803274 AA and AG showed a reduction of 20.69% and 10.92% respectively in mean BChE activity compared to people with genotype GG. No significant differences were identified in AChE activity between rs17880573 alleles or genotypes. In the overall sample, the corresponding reference values were as follows: for AChE activity, 0.62-0.98 D pH/h and for BChE activity, 4796.3-10321.1 U/L for people carrying the allele rs1803274A and 5768.2-11180.4 U/L for people carrying the genotype rs1803274 GG. Conclusion: We strongly recommend using these genetic-based reference values for ChE enzymes in our well-defined population in daily clinical practice.

Introducción. La determinación de la actividad enzimática de la colinesterasa se utiliza comúnmente en la vigilancia biológica de la exposición a pesticidas organofosforados y carbamatos. Sin embargo, los factores genéticos afectan la actividad de la colinesterasa, por lo que la integración de la información sobre genotipos y fenotipos en las pruebas de laboratorio clínico, incrementaría la precisión de los valores de referencia. Objetivo. Establecer los valores de referencia basados en el contexto genético para la actividad enzimática de la acetilcolinesterasa (AChE) y la butirilcolinesterasa (BChE), en una población colombiana. Materiales y métodos. Se incluyeron 397 adultos sanos. La actividad de la acetilcolinesterasa y la de la butirilcolinesterasa, se determinaron en muestras de sangre por potenciometría y espectrofotometría, respectivamente. Los genotipos de los ACHE rs17880573 y BCHE rs1803274 se obtuvieron mediante el ensayo TaqMan y los valores de referencia se estimaron con el programa MedCalc®. Resultados. La frecuencia alélica fue de 10,58 % para rs17880573 A y de 8,82 % para rs1803274 A. Las personas con los genotipos rs1803274 AA y AG, mostraron una reducción en el promedio de la actividad de la butirilcolinesterasa de 20,69 % y de 10,92 %, respectivamente, comparados con aquellas con el genotipo GG. No se encontraron diferencias significativas en la actividad de la acetilcolinesterasa con respecto a los alelos y genotipos del rs17880573. Los valores de referencia determinados para esta población fueron de 0,62-0,98 D pH/h para acetilcolinesterasa y de 4796,3-10321,1 U/L para butirilcolinesterasa, en las personas portadoras del alelo rs1803274 A, y de 5768,2-11180,4 U/L, en las portadoras del genotipo rs1803274 GG. Conclusión. Se recomienda el uso de estos valores de referencia basados en el contexto genético para las colinesterasas, en la práctica clínica diaria en esta población.

SNP/haplotype associations of CCR2 and CCR5 genes with severity of chagasic cardiomyopathy.

BACKGROUND: Chronic inflammation plays a major role in the tissue injury seen in the chronic chagasic cardiomyopathy. The CCR2 and CCR5 chemokine receptors are involved with the type of cellular infiltrate present in cardiac tissue and CCR5-gene variants were previously associated with this pathology. METHODS AND RESULTS: This is a replication study in an independent cohort with larger sample size. Nine SNPs of CCR5 and CCR2 were typified to confirm the association previously found with Chagas disease. Evidence of association with severity was found for the A allele of rs1799864 of CCR2 (pad=0.02; OR=1.91, 95% CI=1.10-3.30), the T allele of the rs1800024 of CCR5 (pad=0.01; OR=1.95, 95% CI=1.13-3.38), and the HHF(∗)2 haplotype (p=0.03, OR=1.65, 95% CI=1.03-2.65). These results were replicated in the study combined with previous data. In this analysis it was replicated the allele T of rs2734648 (pad=0.009, OR=0.52, 95% CI=0.32-0.85) with protection. In addition, the allele G of rs1800023 (pad=0.043, OR=0.61, 95% CI=0.38-0.98), and the HHC haplotype (p=0.004, OR=0.62, 95% CI=0.44-0.86) were also associated with protection. In contrast, the allele A of rs1799864 of CCR2 (pad=0.009; OR=1.90, 95% CI=1.17-3.08); and the allele T of rs1800024 of CCR5 (pad=0.005, OR=1.98, 95% CI=1.22-3.23) were associated with greater severity. No evidence of association between symptomatic and asymptomatic patients was observed. CONCLUSIONS: These results confirm that variants of CCR5 and CCR2 genes and their haplotypes are associated with the severity but not with susceptibility to develop chagasic cardiomyopathy.

Comparison of seven diagnostic tests to detect Trypanosoma cruzi infection in patients in chronic phase of Chagas disease.

OBJECTIVE: To compare the diagnostic performance of seven methods to determine Trypanosoma cruzi infection in patients with chronic Chagas disease. METHODS: Analytical study, using the case-control design, which included 205 people (patients with Chagasic cardiomyopathy, n=100; control group, n=105). Three enzyme linked immunosorbent assays, one indirect hemagglutination assay and one immunochromatographic test were assessed. Additionally, DNA amplification was performed via the PCR method using kinetoplast and nuclear DNA as target sequences. For the comparative analysis of diagnostic tests, the parameters used were sensitivity, specificity, positive and negative predictive values, Receiver Operator Characteristic (ROC), positive and negative likelihood ratio, as well as κ quality analysis. RESULTS: The commercial Bioelisa Chagas test showed the highest sensitivity (98%), specificity (100%), and positive and negative predictive values; ​​additionally, it had the highest discriminatory power. Otherwise, the amplification of T. cruzi DNA in blood samples showed low values of sensitivity (kinetoplast DNA = 51%, nuclear DNA = 22%), but high values of specificity (100%), and moderate to low discriminatory ability. CONCLUSION: The comparative analysis among the different methods suggests that the diagnostic strategy of T. cruzi infection in patients with chronic Chagas disease can be performed using ELISA assays based on recombinant proteins and/or synthetic peptides, which show higher diagnosis performance and can confirm and exclude the diagnosis of T. cruzi infection. The molecular methods show poor performance when used in the diagnosis of patients with chronic Chagas disease.

OBJETIVO: Comparar la capacidad diagnóstica de siete métodos para determinar infección por Trypanosoma cruzi, en pacientes con enfermedad de Chagas crónica. MÉTODOS: Estudio analítico de casos y controles, que incluyó 205 personas (pacientes con miocardiopatía chagásica, n= 100; grupo control, n= 105). Se evaluaron tres inmunoensayos enzimáticos, una hemaglutinación indirecta y una inmunocromatografia. Adicionalmente, se realizó amplificación de ADN de T. cruzi por reacción en cadena de la polimerasa utilizando como secuencias diana ADN de kinetoplasto y nuclear. Para el análisis comparativo de las pruebas diagnósticas, los parámetros utilizados fueron sensibilidad, especificidad, valores predictivo positivo y negativo, análisis ROC, razón de verosimilitud positiva y negativa, así como análisis de calidad κ. RESULTADOS: La prueba de Chagas Bioelisa mostró la mayor sensibilidad (98%), especificidad (100%) y valores predictivos positivo y negativo; además tuvo el mayor poder discriminatorio. En contraste, los ensayos de amplificación de ADN de T. cruzi mostraron baja sensibilidad (ADN de kinetoplasto = 51%, ADN nuclear = 22%), alta especificidad (100%) y de moderada a baja capacidad discriminatoria. CONCLUSIÓN: El análisis comparativo entre los métodos sugiere utilizar como estrategia diagnóstica en pacientes crónicos con enfermedad de Chagas, los ensayos de ELISA con proteínas recombinantes y/o péptidos sintéticos por mostrar un rendimiento diagnóstico superior y tener la capacidad de confirmar y descartar el diagnóstico de infección por T. cruzi. Los métodos moleculares muestran pobre rendimiento para ser utilizados en el diagnóstico de pacientes en fase crónica con enfermedad de Chagas.

Methicillin-resistant Staphylococcus aureus causes both community-associated and health care-associated infections in children at the Hospital Universitario de Santander.

INTRODUCTION: Methicillin-resistant Staphylococcus aureus (MRSA) is a frequent cause of infection in the pediatric population. Initially, MRSA was restricted to hospitals; however, outbreaks in the community among people without health care-related risk factors have been reported worldwide. Currently, MRSA is a frequent cause of both hospital and community-associated infections. OBJECTIVE: To describe the relationships between the molecular characteristics of MRSA isolates (staphylococcal cassette chromosome mec (SCCmec) type and Panton-Valentine leukocidin (PVL) carriage) and the characteristics of infection (the origin and localization of infection) in pediatric patients at the Hospital Universitario de Santander in Bucaramanga, Colombia. MATERIALS AND METHODS: A total of 43 MRSA isolates were obtained from hospitalized pediatric patients. SCCmec typing (I-V), SCCmec IV subtyping and PVL carriage were determined and related to the clinical characteristics. RESULTS: Among the MRSA isolates studied, SCCmec IVc was present in 77%, followed by 16% for SCCmec I and 2% for SCCmec IVa. Two isolates were not typeable (NT). PVL genes were carried by 88% of the MRSA isolates, including the SCCmec IVc/IVa and SCCmec I isolates. SCCmec IV caused both community-acquired infection (CAI) (47%) and nosocomial infection (HAI) (53%). SCCmec IV, PVL-positive MRSA was associated with both CAI (47%) and HAI (53%) and caused mostly SSTI and osteoarticular infection. CONCLUSIONS: These findings suggest that the presence of community-associated MRSA (CA-MRSA) (SCCmec IV and PVL positive) causes both health care-associated infection (HCAI) and nosocomial infection (HAI) in pediatric patients in Colombia.

Methicillin-resistant Staphylococcus aureus causes both c ommunity-associated and health care-associated infections in children at the Hospital Universitario de Santander / Staphylococcus aureus resistente a meticilina causante de infecciones comunitarias y de infecciones asociadas a la atención en salud en pacientes pediátricos del Hospital Universitario de Santander

Introduction: Methicillin-resistant Staphylococcus aureus (MRSA) is a frequent cause of infection in the pediatric population. Initially, MRSA was restricted to hospitals; however, outbreaks in the community among people without health care-related risk factors have been reported worldwide. Currently, MRSA is a frequent cause of both hospital and community-associated infections. Objective: To describe the relationships between the molecular characteristics of MRSA isolates (staphylococcal cassette chromosome mec (SCCmec) type and Panton-Valentine leukocidin (PVL) carriage) and the characteristics of infection (the origin and localization of infection) in pediatric patients at the Hospital Universitario de Santander in Bucaramanga, Colombia. Materials and methods: A total of 43 MRSA isolates were obtained from hospitalized pediatric patients. SCCmec typing (I-V), SCCmec IV subtyping and PVL carriage were determined and related to the clinical characteristics. Results: Among the MRSA isolates studied, SCCmec IVc was present in 77%, followed by 16% for SCCmec I and 2% for SCCmec IVa. Two isolates were not typeable (NT). PVL genes were carried by 88% of the MRSA isolates, including the SCCmec IVc/IVa and SCCmec I isolates. SCCmec IV caused both community-acquired infection (CAI) (47%) and nosocomial infection (HAI) (53%). SCCmec IV, PVL-positive MRSA was associated with both CAI (47%) and HAI (53%) and caused mostly SSTI and osteoarticular infection. Conclusions: These findings suggest that the presence of community-associated MRSA (CA-MRSA) (SCCmec IV and PVL positive) causes both health care-associated infection (HCAI) and nosocomial infection (HAI) in pediatric patients in Colombia.

Introducción. Staphylococcus aureus resistente a la meticilina (SARM) es un agente frecuente de infección en la población pediátrica. Aunque inicialmente las cepas de SARM estaban restringidas a los hospitales, se han reportado a nivel mundial brotes de infección por SARM en individuos sin factores de riesgo y, actualmente, SARM es una causa frecuente de infecciones hospitalarias y comunitarias. Objetivo. Describir la relación entre las características moleculares de aislamientos de SARM (casete cromosómico estafilocócico mec SCCmec y leucocidina Panton-Valentine) y el origen de la infección y su presentación clínica en pacientes pediátricos del Hospital Universitario de Santander en Bucaramanga, Colombia. Materiales y métodos. Se incluyeron 43 aislamientos de SARM obtenidos de niños hospitalizados. La clasificación del SCCmec (I-V) y la subclasificación del SCCmec-IV se realizaron en todos los aislamientos. Además, los genes de la leucocidina Panton-Valentine se detectaron mediante amplificación por PCR. Las características moleculares fueron asociadas con las características clínicas de cada paciente. Resultados. Entre los 43 SARM tipificados, el SCCmec-IVc fue el más frecuente con 77 %, seguido por el SCCmec-I con 16 % y el SCCmec-IVa con 2 %. Tres aislamientos no pudieron ser tipificados. Los genes de la leucocidina Panton Valentine se detectaron en 88 % de los SARM en aislamientos portadores del SCCmec-IVc/IVa y el SCCmec-I. Los SARM SCCmec-IV positivos para la leucocidina Panton-Valentine se asociaron con infecciones adquiridas en la comunidad (47 %) y en el hospital (53 %) con compromiso de piel y tejidos blandos, y en los casos más graves, con compromiso osteoarticular. Conclusiones. Estos resultados sugieren la presencia de cepas SARM-CO (SCCmec-IV positiva para PVL) causantes de infecciones adquiridas en la comunidad y en el medio hospitalario en pacientes pediátricos en Colombia.

Comparison of seven diagnostic tests to detect Trypanosoma cruzi infection in patients in chronic phase of Chagas disease / Comparación de siete pruebas diagnósticas para detectar infección por Trypanosoma cruzi en pacientes en fase crónica de la enfermedad de Chagas

Objective: To compare the diagnostic performance of seven methods to determine Trypanosoma cruzi infection in patients with chronic Chagas disease. Methods: Analytical study, using the case-control design, which included 205 people (patients with Chagasic cardiomyopathy, n= 100; control group, n= 105). Three enzyme linked immunosorbent assays, one indirect hemagglutination assay and one immunochromatographic test were assessed. Additionally, DNA amplification was performed via the PCR method using kinetoplast and nuclear DNA as target sequences. For the comparative analysis of diagnostic tests, the parameters used were sensitivity, specificity, positive and negative predictive values, Receiver Operator Characteristic (ROC), positive and negative likelihood ratio, as well as κ quality analysis. Results: The commercial Bioelisa Chagas test showed the highest sensitivity (98%), specificity (100%), and positive and negative predictive values; additionally it had the highest discriminatory power. Otherwise, the amplification of T. cruzi DNA in blood samples showed low values of sensitivity (kinetoplast DNA= 51%, nuclear DNA= 22%), but high values of specificity (100%), and moderate to low discriminatory ability. Conclusion: The comparative analysis among the different methods suggests that the diagnostic strategy of T. cruzi infection in patients with chronic Chagas disease can be performed using ELISA assays based on recombinant proteins and/or synthetic peptides, which show higher diagnosis performance and can confirm and exclude the diagnosis of T. cruzi infection. The molecular methods show poor performance when used in the diagnosis of patients with chronic Chagas disease.

Objetivo: Comparar la capacidad diagnóstica de siete métodos para determinar infección por Trypanosoma cruzi, en pacientes con enfermedad de Chagas crónica. Métodos: Estudio analítico de casos y controles, que incluyó 205 personas (pacientes con miocardiopatía chagásica, n= 100; grupo control, n= 105). Se evaluaron tres inmunoensayos enzimáticos, una hemaglutinación indirecta y una inmunocromatografia. Adicionalmente, se realizó amplificación de ADN de T. cruzi por reacción en cadena de la polimerasa utilizando como secuencias diana ADN de kinetoplasto y nuclear. Para el análisis comparativo de las pruebas diagnósticas, los parámetros utilizados fueron sensibilidad, especificidad, valores predictivo positivo y negativo, análisis ROC, razón de verosimilitud positiva y negativa, así como análisis de calidad κ. Resultados: La prueba Bioelisa para Chagas mostró la mayor sensibilidad (98%), especificidad (100%) y valores predictivos positivo y negativo; además ésta tuvo el mayor poder discriminatorio. En contraste, los ensayos de amplificación de ADN de T. cruzi mostraron baja sensibilidad (ADN de kinetoplasto= 51%, ADN nuclear= 22%), alta especificidad (100%) y de moderada a baja capacidad discriminatoria. Conclusión: El análisis comparativo entre los métodos sugiere utilizar como estrategia diagnóstica en pacientes crónicos con enfermedad de Chagas, los ensayos de ELISA con proteínas recombinantes y/o péptidos sintéticos por mostrar un rendimiento diagnóstico superior y tener la capacidad de confirmar y descartar el diagnóstico de infección por T. cruzi. Los métodos moleculares muestran pobre rendimiento para ser utilizados en el diagnóstico de pacientes en fase crónica con enfermedad de Chagas.

Molecular typing and virulence characteristic of methicillin-resistant Staphylococcus aureus isolates from pediatric patients in Bucaramanga, Colombia.

BACKGROUND: Staphylococcus aureus is among the most common global nosocomial pathogens. The emergence and spread of methicillin-resistant Staphylococcus aureus (MRSA) is a public health problem worldwide that causes nosocomial and community infections. The goals of this study were to establish the clonal complexes (CC) of the isolates of MRSA obtained from pediatric patients in a university hospital in Colombia and to investigate its molecular characteristics based on the virulence genes and the genes of staphylococcal toxins and adhesins. METHODS: A total of 53 MRSA isolates from pediatric patients with local or systemic infections were collected. The MRSA isolates were typed based on the SCCmec, MLST, spa and agr genes. The molecular characterization included the detection of Panton-Valentine Leukocidin, superantigenic and exfoliative toxins, and adhesin genes. The correlation between the molecular types identified and the profile of virulence factors was determined for all isolates. RESULTS: Four CC were identified, including CC8, CC5, CC80 and CC78. The ST8-MRSA-IVc-agrI was the predominant clone among the isolates, followed by the ST5-MRSA-I-agrII and ST5-MRSA-IVc-agrII clones. Twelve spa types were identified, of which t10796 and t10799 were new repeat sequences. The isolates were carriers of toxin genes, and hlg (100%), sek (92%) and pvl (88%) were the most frequent. Ten toxin gene profiles were observed, and the most frequent were seq-sek-hlg (22.6%), sek-hlg (22.6%), seb-seq-sek-hlg (18.9%) and seb-sek-hlg (15.1%). The adhesion genes were present in most of the MRSA isolates, including the following: clf-A (89%), clf-B (87%), fnb-A (83%) and ica (83%). The majority of the strains carried SCCmec-IVc and were identified as causing nosocomial infection. No significant association between a molecular type and the virulence factors was found. CONCLUSION: Four major MRSA clone complexes were identified among the isolates. ST8-MRSA-IVc-agrI pvl+ (USA300-LV) was the most frequent, confirming the presence of community-associated MRSA in Colombian hospitals.