In vitro biological activity of extracts from marine bacteria cultures against Toxoplasma gondii and Mycobacterium tuberculosis.

AIMS: To evaluate the biological activity of extracts from cultures of marine bacteria against Toxoplasma gondii and Mycobacterium tuberculosis. METHODS AND RESULTS: Ethyl acetate extracts obtained from seven marine bacteria were tested against T. gondii GFP-RH and M. tuberculosis H37Rv. The cytotoxicity on HFF-1 cells was measured by a microplate resazurin fluorescent approach, and the haemolytic activity was determined photometrically. The extracts from Bacillus sp. (INV FIR35 and INV FIR48) affected the tachyzoite viability. The extracts from Bacillus, Pseudoalteromonas, Streptomyces and Micromonospora exhibited effects on infection and proliferation processes of parasite. Bacillus sp. INV FIR48 extract showed an minimum inhibitory concentration value of 50 µg ml-1 against M. tuberculosis H37Rv. All the extracts exhibited relatively low toxicity to HFF-1 cells and the primary culture of erythrocytes, except Bacillus sp. INV FIR35, which decreased cell viability under 20%. Liquid chromatography coupled to mass spectrometry analysis of the most active bacterial extract Bacillus sp. INV FIR48 showed the presence of peptide metabolites related to surfactin. CONCLUSIONS: The extract from culture of deep-sea Bacillus sp. INV FIR48 showed anti-T. gondii and anti-tuberculosis (TB) biological activity with low cytotoxicity. In addition, peptide metabolites were detected in the extract. SIGNIFICANCE AND IMPACT OF THE STUDY: Toxoplasmosis and TB are among the most prevalent diseases worldwide, and the current treatment drugs exhibit side effects. This study confirm that marine bacteria are on hand sources of anti-infective natural products.

Identification of Toxoplasma gondii adhesins through a machine learning approach.

Toxoplasma gondii, as other apicomplexa, employs adhesins transmembrane proteins for binding and invasion to host cells. Search and characterization of adhesins is pivotal in understanding Apicomplexa invasion mechanisms and targeting new druggable candidates. This work developed a machine learning software called ApiPredictor UniQE V2.0, based on two approaches: support vector machines and multilayer perceptron, to predict adhesins proteins from amino acid sequences. By using ApiPredictor UniQE V2.0, five SAG-Related Sequences (SRSs) were identified within the Toxoplasma gondii proteome. One of those candidates, TgSRS12B, was cloned in plasmid pEXP5-CT/TOPO and expressed in E. coli BL21 DE3. The resulting recombinant protein was purified via affinity chromatography. Co-precipitation assays in CaCo and Muller cells showed interactions between TgSRS12B-His-tagged and the membrane fractions from both human cell lines. In conclusion, we demonstrated that ApiPredictor UniQE V2.0, a bioinformatic free software, was able to identify TgSRS12B as a new adhesin protein.

Protein targets of thiazolidinone derivatives in Toxoplasma gondii and insights into their binding to ROP18.

BACKGROUND: Thiazolidinone derivatives show inhibitory activity (IC50) against the Toxoplasma gondii parasite, as well as high selectivity with high therapeutic index. To disclose the target proteins of the thiazolidinone core in this parasite, we explored in silico the active sites of different T. gondii proteins and estimated the binding-free energy of reported thiazolidinone molecules with inhibitory effect on invasion and replication of the parasite inside host cells. This enabled us to describe some of the most suitable structural characteristics to design a compound derived from the thiazolidinone core. RESULTS: The best binding affinity was observed in the active site of kinase proteins, we selected the active site of the T. gondii ROP18 kinase, because it is an important factor for the virulence and survival of the parasite. We present the possible effect of a derivative of thiazolidinone core in the active site of T. gondii ROP18 and described some characteristics of substituent groups that could improve the affinity and specificity of compounds derived from the thiazolidinone core against T. gondii. CONCLUSIONS: The results of our study suggest that compounds derived from the thiazolidinone core have a preference for protein kinases of T. gondii, being promising compounds for the development of new drugs with potential anti-toxoplasmosis activity. Our findings highlight the importance of use computational studies for the understanding of the action mechanism of compounds with biological activity.

Role of the 52 KDa thioredoxin protein disulfide isomerase of Toxoplasma gondii during infection to human cells.

Toxoplasma protein disulfide isomerase (PDI) is a 52 KDa thioredoxin of interest because have a great immunogenicity for humans. We cloned and produced a recombinant protein (recTgPDI) used to test its effect during infection to different human cell lines (epithelial and retinal). We also determine if there were differences in gen expression during in vitro infection. Expression of the gen was lower after entry into the host cells. PDI's inhibitors bacitracin and nitroblue tetrazolium reduced the percent of infected cells and small amounts of recTgPDI proteins interfered with the invasion step. All these results support a role of Toxoplasma PDI during the first steps of infection (adhesion and invasion). Toxoplasma PDI is a protein linked to early steps of invasion, it would be of importance to identify the host proteins substrates during invasion steps.

Detection by PCR of pathogenic protozoa in raw and drinkable water samples in Colombia.

We evaluated the presence of DNA of Giardia, Toxoplasma, and Cryptosporidium by PCR, and of Giardia and Cryptosporidium genera by immunofluorescence antibody test (IFAT), in water samples, before, during, and after plant treatment for drinkable water. We applied this method in 38 samples of 10 l of water taken from each of the water treatment steps and in 8 samples taken at home (only for Toxoplasma PCR) in Quindio region in Colombia. There were 8 positive samples for Cryptosporidium parvum (21 %), 4 for Cryptosporidium hominis (10.5 %), 27 for Toxoplasma gondii (58.6 %), 2 for Giardia duodenalis assemblage A (5.2 %), and 5 for G. duodenalis assemblage B (13.1 %). By IFAT, 23 % were positive for Giardia and 21 % for Cryptosporidium. An almost perfect agreement was found between IFAT and combined results of PCR, by Kappa composite proportion analysis. PCR positive samples were significantly more frequent in untreated raw water for C. parvum (p = 0.02). High mean of fecal coliforms, high pH values, and low mean of chlorine residuals were strongly correlated with PCR positivity for G. duodenalis assemblage B. High pH value was correlated with PCR positivity for C. parvum. Phylogenetic analysis of DNA sequences was possible, showing water and human clinical sequences for Toxoplasma within the same phylogenetic group for B1 repeated sequence. PCR assay is complementary to IFAT assay for monitoring of protozoa in raw and drinkable water, enabling species identification and to look for phylogenetic analysis in protozoa from human and environmental sources.

MSCA: a spectral comparison algorithm between time series to identify protein-protein interactions.

BACKGROUND: The interactions between pathogen proteins and their hosts allow pathogens to manipulate host cellular mechanisms to their advantage. The identification of host proteins that are targeted by virulent pathogen proteins is crucial to increase our understanding of infection mechanisms and to propose new therapeutics that target pathogens. Understanding the virulence mechanisms of pathogens requires a detailed molecular description of the proteins involved, but acquiring this knowledge is time consuming and prohibitively expensive. Therefore, we develop a statistical method based on hypothesis testing to compare the time series obtained from conversion of the physicochemical characteristics of the amino acids that form the primary structure of proteins and thus to propose potential functional relation between proteins. We called this algorithm the multiple spectral comparison algorithm (MSCA); the MSCA was inspired by the BLASTP tool and was implemented in R code. The algorithm compares and relates multiple time series according to their spectral similarities, and the biological relation between them could be interpreted as either a similar function or protein-protein interaction (PPI). RESULTS: A simulation study showed that the MSCA works satisfactorily well when we compare unequal time series generated from ARMA processes because its power was close to 1. The MSCA presented a 70% average accuracy of detecting protein interactions using a threshold of 0.7 for our spectral measure, indicating that this algorithm could predict novel PPIs and pathogen-host interactions (PHIs) with acceptable confidence. The MSCA also was validated by its identification of well-known interactions of the human proteins MAGI1, SCRIB and JAK1, as well as interactions of the virulence proteins ROP16, ROP18, ROP17 and ROP5. We verified the spectral similarities for human intraspecific PPIs and PHIs that were previously demonstrated experimentally by other authors. We suggest that human GBP (GTPase group induced by interferon) and the CREB transcription factor family could be human substrates for the complex of ROP18, ROP17 and ROP5. CONCLUSIONS: Using multiple-hypothesis testing between the spectral densities of a set of unequal time series, we developed an algorithm that is able to identify the similarities or interactions between a set of proteins.

Ocular cytokinome is linked to clinical characteristics in ocular toxoplasmosis.

PURPOSE: To determine the cytokine levels in aqueous humor (AH) of Colombian patients with active ocular toxoplasmosis (OT), and to correlate them with their clinical characteristics. METHODS: 27 Cytokines/chemokines were assayed in 15 AH samples (nine patients with diagnosis of OT biologically-confirmed and six controls that underwent cataract surgery). Correlations were assessed between cytokine/chemokine levels, type of inflammatory response (Th1, Th2, Th17, Treg), and clinical characteristics. RESULTS: Th2 predominant response was related to more severe clinical features. The presence of VEGF and IL-5 was related to higher number of recurrences. Growth factors (VEGF, FGF, PDGF-ß), were related to higher number of lesions. Patients infected by type-I/III strains had a particular intraocular cytokine-pattern. CONCLUSIONS: Th2 response was related to more severe clinical characteristics in patients infected by Type I/III strains. IL-5 and VEGF were associated with recurrences. We correlate for the first time, specific cytokine-patterns with clinical characteristics and with the infecting Toxoplasma strain.

Estimations of the number people with mental diseases associated with toxoplasmosis and identification of risk factors by continent.

Strong evidence exists based on metanalysis of the relationship between toxoplasmosis and many psychiatric diseases: schizophrenia, bipolar disorder, and suicidal behavior. Herein, we estimate the number of cases based on the attributable fraction due to toxoplasmosis on these diseases. The population attributable fraction of mental disease associated with toxoplasmosis was 20,4% for schizophrenia; 27,3% for bipolar disorder; and 0,29% for suicidal behavior (self-harm). The lower and upper estimated number of people with mental disease associated with toxoplasmosis was 4'816.491 and 5'564.407 for schizophrenia; 6'348.946 and 7'510.118,82 for bipolar disorder; and 24.310 and 28.151 for self-harm; for a global total lower estimated number of 11'189.748 and global total upper estimated number of 13'102.678 people with mental disease associated with toxoplasmosis for the year 2019. According to the prediction through the Bayesian model of risk factors for toxoplasmosis associated with mental disease, these varied in importance geographically; thus, in Africa, the most important risk factor was water contamination and in the European region, the cooking conditions of meats. Toxoplasmosis and mental health should be a research priority given the enormous potential impact of reducing this parasite in the general population.

Immune response against toxoplasmosis-some recent updates RH: Toxoplasma gondii immune response.

AIMS: Cytokines, soluble mediators of immunity, are key factors of the innate and adaptive immune system. They are secreted from and interact with various types of immune cells to manipulate host body's immune cell physiology for a counter-attack on the foreign body. A study was designed to explore the mechanism of Toxoplasma gondii (T. gondii) resistance from host immune response. METHODS AND RESULTS: The published data on aspect of host (murine and human) immune response against T. gondii was taken from Google scholar and PubMed. Most relevant literature was included in this study. The basic mechanism of immune response starts from the interactions of antigens with host immune cells to trigger the production of cytokines (pro-inflammatory and anti-inflammatory) which then act by forming a cytokinome (network of cytokine). Their secretory equilibrium is essential for endowing resistance to the host against infectious diseases, particularly toxoplasmosis. A narrow balance lying between Th1, Th2, and Th17 cytokines (as demonstrated until now) is essential for the development of resistance against T. gondii as well as for the survival of host. Excessive production of pro-inflammatory cytokines leads to tissue damage resulting in the production of anti-inflammatory cytokines which enhances the proliferation of Toxoplasma. Stress and other infectious diseases (human immunodeficiency virus (HIV)) that weaken the host immunity particularly the cellular component, make the host susceptible to toxoplasmosis especially in pregnant women. CONCLUSION: The current review findings state that in vitro harvesting of IL12 from DCs, Np and MΦ upon exposure with T. gondii might be a source for therapeutic use in toxoplasmosis. Current review also suggests that therapeutic interventions leading to up-regulation/supplementation of SOCS-3, IL12, and IFNγ to the infected host could be a solution to sterile immunity against T. gondii infection. This would be of interest particularly in patients passing through immunosuppression owing to any reason like the ones receiving anti-cancer therapy, the ones undergoing immunosuppressive therapy for graft/transplantation, the ones suffering from immunodeficiency virus (HIV) or having AIDS. Another imortant suggestion is to launch the efforts for a vaccine based on GRA6Nt or other similar antigens of T. gondii as a probable tool to destroy tissue cysts.

Toxoplasma gondii: P30 peptides recognition pattern in human toxoplasmosis.

In this study, human sera reactivity against nine peptides derived from the Toxoplasma gondii P30 protein was assessed by ELISA in patients with different clinical forms of toxoplasmosis. Same as has been reported in mice, sera from congenital, ocular and chronic asymptomatic toxoplasmosis patients recognized more strongly peptides from the protein's carboxy-terminus, being peptide 2017 (amino acids 301-320) the one most strongly recognized by sera from patients with ocular toxoplasmosis. Serum samples collected from 13 patients without ocular infection, 13 with inactive chorioretinal scars, 6 with active ocular infection and 10 seronegative individuals were then screened for anti-2017 IgG. Peptide 2017 was recognized by all patients' samples but not by sera from T. gondii-seronegative individuals. No statistically significant differences were found between the absorbance levels of groups with and without lesions or with active or inactive ocular lesions, as determined by ANOVA.

R Script Approach to Infer Toxoplasma Infection Mechanisms From Microarrays and Domain-Domain Protein Interactions.

Pathogen-host protein-protein interaction systems examine the interactions between the protein repertoires of 2 distinct organisms. Some of these pathogen proteins interact with the host protein system and may manipulate it for their own advantages. In this work, we designed an R script by concatenating 2 functions called rowDM and rowCVmed to infer pathogen-host interaction using previously reported microarray data, including host gene enrichment analysis and the crossing of interspecific domain-domain interactions. We applied this script to the Toxoplasma-host system to describe pathogen survival mechanisms from human, mouse, and Toxoplasma Gene Expression Omnibus series. Our outcomes exhibited similar results with previously reported microarray analyses, but we found other important proteins that could contribute to toxoplasma pathogenesis. We observed that Toxoplasma ROP38 is the most differentially expressed protein among toxoplasma strains. Enrichment analysis and KEGG mapping indicated that the human retinal genes most affected by Toxoplasma infections are those related to antiapoptotic mechanisms. We suggest that proteins PIK3R1, PRKCA, PRKCG, PRKCB, HRAS, and c-JUN could be the possible substrates for differentially expressed Toxoplasma kinase ROP38. Likewise, we propose that Toxoplasma causes overexpression of apoptotic suppression human genes.

Ciencia, salud pública y toma de decisiones: [Editorial] / Science, public health and decision making: [Editorial]

La pandemia por COVID-19 ha obligado a los gobiernos de todo el mundo a la toma de decisiones con información preliminar, insuficiente o discutible en argumentos científicos, algo que como académicos debemos entender y acompañar y se convierte en un reto mayor: ¿cómo dar recomendaciones con información limitada y reducir las incertidumbres? Para ello, primero que todo, se debe reconocer que estos procesos están sometidos a cambios según la evolución del conocimiento y la comunicación de la información se vuelve crucial para evitar minar la confianza pública ante los cambios. Es así como muchas recomendaciones para el manejo de COVID 19 han venido evolucionando a medida que se conoce mejor la patogénesis, sus mecanismos de transmisión y las particularidades en la respuesta inmune y, por ejemplo, pasamos de una recomendación inicial de medidas de prevención que incluía limpieza de superficies a una en la cual el énfasis es la limitación en número de personas en reunión. La Asociación Colombiana de infectología junto con otras 27 sociedades científicas lleva tres diferentes actualizaciones de recomendaciones basadas en evidencia en los primeros 12 meses de pandemia, es decir cada tres meses se han venido revisando las más de 250 recomendaciones, lo cual ha significado un trabajo enorme de revisión, discusión y presentación final las cuales, afortunadamente, han sido acogidas y tomadas como base de las decisiones gubernamentales.

The COVID-19 pandemic has forced governments around the world to take decisions on preliminary, insufficient The COVID-19 pandemic has forced governments around the world to make decisions with preliminary, insufficient or debatable information on scientific grounds, something that as academics we must understand and accompany and which becomes a major challenge: how to give recommendations with limited information and reduce uncertainties? To do this, first of all, it must be recognised that these processes are subject to change as knowledge evolves and the communication of information becomes crucial to avoid undermining public confidence in the face of change. Thus, many recommendations for the management of COVID 19 have evolved as the pathogenesis, transmission mechanisms and particularities of the immune response have become better understood and, for example, we have gone from an initial recommendation of measures to be taken in response to COVID 19 to a recommendation of measures to be taken in response to COVID 19, we have moved from an initial recommendation for prevention measures that included surface cleaning to one in which the emphasis is on limiting the number of people at a meeting. The Colombian Association of Infectious Diseases, together with 27 other scientific societies, has scientific societies has three different updates of evidence-based evidence-based recommendations in the first 12 months of a pandemic, i.e. every months of the pandemic, i.e. every three months, the more than 250 recommendations have been This has meant an enormous work of review, discussion and final presentation which, fortunately, have been accepted and taken as a basis for governmental decisions. and taken as a basis for governmental decisions.

Vacunas para COVID19: las lecciones de un triunfo de la ciencia biomédica: [Editorial] / Vaccines for COVID19: lessons from the triumph of the biomedical science: [Editorial]

Frente al escepticismo de encontrar una vacuna para COVID19, los resultados de los ensayos clínicos de Fase III dieron la sentencia: se lograron vacunas con alto grado de eficacia que llega al 70% a 95%. Al momento de escribir esta editorial, dos de ellas ya tienen autorización para uso de emergencia por el FDA. La OMS realiza un seguimiento cotidiano a los avances de candidatos vacunales, el reporte para el 22 de Diciembre encontraba 57 en fases de evaluación clínica (entre estas 11 en fase III) y 166 en fase preclínica.

In the face of skepticism about finding a vaccine for COVID19 , the results of the Phase III clinical trials were conclusive: vaccines with a high degree of efficacy of 70% to 95% were achieved. At the time of writing this editorial, two of them have already been authorized for emergency use by the FDA. The WHO monitors the progress of vaccine candidates on a daily basis; the report as of December 22nd found 57 in clinical evaluation phases (including 11 in Phase III) and 166 in preclinical phase.

Detection of protozoa in water samples by formalin/ether concentration method.

Methods to detect protozoa in water samples are expensive and laborious. We evaluated the formalin/ether concentration method to detect Giardia sp., Cryptosporidium sp. and Toxoplasma in water. In order to test the properties of the method, we spiked water samples with different amounts of each protozoa (0, 10 and 50 cysts or oocysts) in a volume of 10 L of water. Immunofluorescence assay was used for detection of Giardia and Cryptosporidium. Toxoplasma oocysts were identified by morphology. The mean percent of recovery in 10 repetitions of the entire method, in 10 samples spiked with ten parasites and read by three different observers, were for Cryptosporidium 71.3 ± 12, for Giardia 63 ± 10 and for Toxoplasma 91.6 ± 9 and the relative standard deviation of the method was of 17.5, 17.2 and 9.8, respectively. Intraobserver variation as measured by intraclass correlation coefficient, was fair for Toxoplasma, moderate for Cryptosporidium and almost perfect for Giardia. The method was then applied in 77 samples of raw and drinkable water in three different plant of water treatment. Cryptosporidium was found in 28 of 77 samples (36%) and Giardia in 31 of 77 samples (40%). Theses results identified significant differences in treatment process to reduce the presence of Giardia and Cryptosporidium. In conclusion, the formalin ether method to concentrate protozoa in water is a new alternative for low resources countries, where is urgently need to monitor and follow the presence of theses protozoa in drinkable water.

Evaluación de la prueba de avidez para el seguimiento de niños tratados por toxoplasmosis congénita durante el primer año de vida / Evaluation of the avidity test for the follow up on children treated for congenital toxoplasmosis during the first year of life

RESUMEN Objetivos: determinar la utilidad de la prueba de avidez en el seguimiento de los pacientes diagnosticados con toxoplasmosis congénita a través de la evaluación de su comportamiento en el tiempo. Metodología: estudio retrospectivo a partir de los datos en historias clínicas de niños que tuvieron confirmación diagnóstica y tratamiento para toxoplasmosis congénita, realizado en consulta de toxoplasmosis, tercer nivel de referencia en el centro de salud de la Universidad del Quindío. Se estudiaron 21 niños que fueron seleccionados de una cohorte inicial de 168 pacientes, reclutados en los programas de tamizaje prenatal y los programas de prevención o niños que acudieron para el diagnóstico neonatal. Resultados: no se encontró relación estadísticamente significativa entre el porcentaje de avidez baja en el primer mes y haber recibido tratamiento prenatal (p = 0,47). Tampoco entre la primera y los niveles de IgG o los meses de vida, a pesar de haber recibido tratamiento posnatal. Sin embargo, al estudiar específicamente el grupo de niños de 5 meses de edad, se encontró una correlación significativa con los niveles de IgG anti-Toxoplasma (p = 0,01). Conclusión: en esta cohorte de niños colombianos con toxoplasmosis congénita se encontraron los mismos resultados reportados en series previas con un mayor número de casos en Italia. La avidez no mostró ser útil para el seguimiento de los niños con toxoplasmosis congénita.

SUMMARY Objectives: To determine the use of avidity testing in the follow up of patients diagnosed with congenital toxoplasmosis, through the observation of its behavior in time. Methods: Retrospective study from clinical records of children with confirmed diagnosis and treatment for congenital toxoplasmosis, which took place on atoxoplasmosis consultation in the third reference level University of Quindío clinic. A total of 21 children were selected among an initial cohort of 168 patients, recruited during prenatal screening, neonatal screening or children that attended for neonatal diagnosis. Results: There was no statistical significance found between low avidity during the first month and having received prenatal treatment (p=0,47). There was no statistical relationship either between the percentage of avidity and the levels of IgG or the months of age, despite having received postnatal treatment. Nevertheless, when studying specifically the group of children > 5 months of age a significant correlation was found with levels of IgG (p=0,01). Conclusion: In this cohort of Colombian children with congenital toxoplasmosis, the same results were found comparing with those reported in series with greater number of cases. Avidity testing did not prove to be useful for the follow up of children with congenital toxoplasmosis.

Genetic and biologic characteristics of Toxoplasma gondii isolates in free-range chickens from Colombia, South America.

The prevalence of Toxoplasma gondii in free-ranging chickens is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. The prevalence of T. gondii in 77 free-range chickens (Gallus domesticus) from Colombia, South America was determined. Antibodies to T. gondii were assayed by the modified agglutination test (MAT), and found in 32 (44.4%) of 72 chickens with titers of 1:5 in 4, 1:10 in 3, 1:20 in 1, 1:40 in 1, 1:80 in 8, 1:160 in 8, 1:320 in 3, and 1:640 or higher in 4. Hearts and brains of 31 seropositive chickens were pooled and bioassayed in mice. Tissues from 32 (16+16) seronegative chickens were pooled and fed to two, T. gondii-free cats, and tissues from nine chickens without matching sera were fed to one T. gondii-free cat. Feces of cats were examined for oocysts. T. gondii oocysts were excreted by a cat that was fed tissues of 16 seronegative chickens. T. gondii was isolated by bioassay in mice from 23 chickens with MAT titers of 1:20 or higher. All infected mice from 16 of the 23 isolates died of toxoplasmosis. Overall, 82 (81.1%) of 101 mice that became infected after inoculation with chicken tissues died of toxoplasmosis. Genotyping of these 24 isolates using polymorphisms at the SAG2 locus indicated that seven T. gondii isolates were Type I, 17 were Type III, and none was Type II. Phenotypically, T. gondii isolates from chickens from Colombia were similar to isolates from Brazil but different from the isolates from North America; most isolates from chickens from Brazil and Colombia were lethal for mice whereas isolates from North America did not kill inoculated mice. Genetically, none of the T. gondii isolates from Colombia and Brazil was SAG2 Type II, whereas most isolates from chickens from North America were Type II. This is the first report of genetic characterization of T. gondii isolates from Colombia, South America.

[Risk factors for Toxoplasma gondii infection in pregnant women in Armenia, Colombia]. / Factores de riesgo en mujeres embarazadas, infectadas por Toxoplasma gondii en Armenia- Colombia.

OBJECTIVES: To determine the risk factors associated with acute toxoplasmosis during pregnancy in Armenia. METHODS: Case-control study; 14 cases and 34 controls (mean ages 23 +/- 5.5 and 23 +/- 5.1 respectively; p = 0.93). Cases were pregnant women with serological criteria for acute toxoplasmosis and controls were seronegative pregnant women for Toxoplasma IgG. RESULTS: The risk factors more strongly predictive of acute toxoplasmosis in pregnant women were: eating undercooked meat (OR: 13.2; 95% CI: 1.3-132; p = 0.01), drinking beverages prepared with un-boiled water (OR: 4.5; 95% CI: 1.1-17; p = 0.01), and contact with cats aged less than 6 months (OR: undefined, p = 0.01). Drinking of bottled water was a protective factor (OR: 0.24; 95% CI: 0.06-0.95; p = 0.02). CONCLUSIONS: 42% of Toxoplasma gondii infections in pregnant women Armenia were associated to contact with young cats and to consumption of undercooked meat. Drinking of bottled water to prevent toxoplasma infection during pregnancy is also recommended.

[Prevalence of giardiasis and intestinal parasites in pre-school children from homes being attended as part of a state programme in Armenia, Colombia]. / Prevalencia de giardiasis y parásitos intestinales en preescolares de hogares atendidos en un programa estatal en Armenia, Colombia.

OBJECTIVE: Determining the prevalence of giardiasis and intestinal parasitism in pre-school children from the Instituto Colombiano de Bienestar Familiar (ICBF). MATERIALS AND METHODS: Three serial faecal samples were collected from 328 children following informed consent from their legal guardians. Microscopic and macroscopic tests were made using 1% Lugol, 0.83% saline solution, saline-eosin solution and Kato Katz and Ritchie's test as a confirming test. Positive samples were preserved in saline formol solution. RESULTS: Pathogen parasites had the following prevalence frequencies: 2.4% for Ascaris lumbricoides, 0.6% for Hymenolepsis nana, 2.1% for Trichuris trichura, 6.1% for Blastocystis hominis and 13% for Giardia lamblia. CONCLUSIONS: The results of this work showed low helminth frequency compared to that for protozoa; control strategies using single doses of Albendazol are therefore not useful. The most prevalent pathogen parasite was Giardia lamblia in children from the ICBF in Armenia. Periodic surveillance of parasites in children is thereby recommended. The prevalence of Giardia lamblia was not statistically related to the children's nutritional state. Most Giardia-infected children were asymptomatic.

El proceso de validación del conocimiento: el indispensable valor de la revista científica: [Editorial] / The knowledge validation process: the fundamental value of the scientific journal: [Editorial]

Esta pandemia ha dejado grandes lecciones sobre la literatura científica y la evaluación crítica del conocimiento. Aunque grandes revistas, egidas del rigor para validar conocimiento, tuvieron errores estrepitosos, la lección final es que la revisión por pares es el mejor sistema, y hasta ahora el único, que puede garantizar que un trabajo de investigación se ha realizado dentro de las exigencias de la ciencia formal y como se escribe habitualmente, es el menos malo de todos los otros sistemas de evaluación del trabajo científico. En medicina esto es crítico por su implicación en vidas humanas, pero nunca se debe esperar que este proceso esté exento de equivocaciones, la revista JAMA al respecto tuvo una editorial con un título muy diciente: "errar es humano y corregirlo es divino"

This pandemic has left us great lessons regarding scientific literature and the critical evaluation of knowledge. Although important journals that are rigorous when validating knowledge, had resounding errors, the ultimate lesson is that peer review is the best system, and until now the only one, that can ensure that a research work has been carried following scientific requirements, and as it is usually stated, it is the least worse scientific work evaluation systems when compared to others3­5. In medicine, this is critical given the way it affects human lives, but one should never expect this process to be error-free; JAMA journal had an editorial with a very telling title in this regard: "To err is human and to correct it is divine".