Molecular Diagnosis as an Alternative for Public Health Surveillance of Leptospirosis in Colombia.

Leptospirosis represents a public health problem in Colombia. However, the underreporting of the disease is an unfortunate reality, with a clear trend towards a decrease in cases since 2019, when the guidelines for its confirmatory diagnosis changed with the requirement of two paired samples. The purpose of this review is to highlight the importance of leptospirosis. While the access to rapid diagnosis is available at practically all levels of care for dengue and malaria, leptospirosis-a doubly neglected disease-deserves recognition as a serious public health problem in Colombia. In this manner, it is proposed that molecular tests are a viable diagnostic alternative that can improve the targeted treatment of the patient and the timeliness of data and case reporting to SIVIGILA, and reduce the underreporting of the disease. Taking advantage of the strengthened technological infrastructure derived from the SARS-CoV-2 pandemic for molecular diagnosis in Colombia, with a network of 227 laboratories distributed throughout the national territory, with an installed capacity for PCR testing, it is proposed that molecular diagnosis can be used as an alternative for early diagnosis. This would allow case confirmation through the public health network in Colombia, and, together with the microagglutination (MAT) technique, the epidemiological surveillance of this disease in this country would be strengthened.

Bio-SELEX: A Strategy for Biomarkers Isolation Directly from Biological Samples.

Bio-SELEX is a revolutionary method for the discovery of novel biomarkers within biological samples, offering profound insights into diagnosing both infectious and non-infectious diseases. This innovative strategy involves three crucial steps: Traditional SELEX, Pull Down, and mass spectrometry. Firstly, Traditional SELEX involves the systematic selection of specific nucleic acid sequences (aptamers) that bind to the target molecules of interest. These aptamers are generated through iterative rounds of selection, amplification, and enrichment, ultimately yielding highly selective ligands. Secondly, the Pull-Down phase employs these aptamers to capture and isolate the target biomarkers from complex biological samples. This step ensures the specificity of the selected aptamers in binding to their intended targets. Lastly, mass spectrometry is utilized to identify and quantify the captured biomarkers, providing precise information about their presence and concentration in the sample. These quantitative data are invaluable in disease diagnosis and monitoring. Bio-SELEX's significance lies in its ability to discover biomarkers for a wide range of diseases, spanning infectious and non-infectious conditions. This approach holds great promise for early disease detection, personalized medicine, and the development of targeted therapies. By harnessing the power of aptamers and mass spectrometry, Bio-SELEX advances our understanding of disease biology and opens new avenues for improved healthcare.

Biomarkers for the diagnosis, treatment follow-up, and prediction of cardiac complications in Chagas disease in chronic phase: Recent advances.

Chagas disease is caused by the Trypanosoma cruzi parasite and is transmitted by infected triatomine bugs. This infection affects approximately 8 million people in the Americas, and due to globalisation and displacement, it is becoming increasingly common to find infected patients worldwide. Diagnosis of the disease in its acute form is relatively simple, as the parasite can be detected in peripheral blood smears, and symptoms are visible. However, in its chronic condition, the parasite is almost undetectable, and indirect tests are necessary to determine the presence of antibodies in infected patients. It is important to note that a single test is not enough to confirm the disease in this phase, as a second serological test should confirm the diagnosis. If the results are contradictory, a third test should be performed to confirm or discard the disease. Unfortunately, laboratories may not have access to all necessary tests in many rural areas where the disease is more frequent. Rapid tests to diagnose this disease present problems, such as significant variations in sensitivity and specificity in different countries. Therefore, searching for new biomarkers that allow for optimal correlation is essential. In this work, we have searched scientific literature from the last 10 years for mentions of novel biomarkers for diagnosis, treatment follow-up, and prediction of cardiac complications in Chagas disease in its chronic phase.

Biliary Tract Microbiota Similarities in Pancreatic Ductal Adenocarcinoma / Similitudes en la Microbiota de Tracto Biliar en Adenocarcinoma Ductal de Páncreas

Abstract Objective: to analyze microbiota profiles in the biliary tract, of pancreatic ductal adenocarcinoma (PDAC) patients and gallstones patients, in order to identify dif ferences, which may contribute to a better understanding of PDAC carcinogenesis. Methods: using microbiota analysis, a total of 25 samples from 14 patients were collected during surgery and compared. Samples were divided into three groups; one GS group (N = 3), and two PDAC groups; PDAC gallbladder group (N = 11) and PDAC brush group (N = 11). Results: upon comparison of bacterial communities' alpha and beta diversity indices and relative abundances by group (anatomic site) and condition (GS vs PDAC), we found no statistically significant results. However, we can highlight the high similarity of the compared parameters among the two different anatomic locations over the biliary tract in PDAC patients. Conclusion: to the best of our knowledge, this is the first study comparing two different anatomic locations over the biliary tract in PDAC patients. Among PDAC groups microbiota along the semi-closed duct system of the biliary tract showed substantial similarity, reflected in the alpha and beta diversity indices and relative abundances.

Resumen Objetivo: analizar los perfiles de microbiota en el tracto biliar de pacientes con adenocarcinoma ductal pancreático (PDAC) y pacientes con cálculos biliares (GS), con el fin de identificar diferencias, lo que puede contribuir a una mejor comprensión de la carcinogénesis de PDAC. Métodos: mediante análisis de microbiota, se recolectaron durante la cirugía un total de 25 muestras de 14 pacientes y se compararon. Las muestras se dividieron en tres grupos; Grupo GS (N = 3) y dos grupos PDAC; Grupo de vesícula biliar PDAC (N = 11) y grupo de cepillado PDAC (N = 11). Resultados: al comparar los índices de diversidad alfa y beta de las comunidades bacterianas y las abundancias relativas por grupo (sitio anatómico) y condición (GS vs PDAC), no encontramos diferencias estadísticamente significativas. Sin embargo, podemos destacar la gran similitud de los parámetros comparados entre las dos ubicaciones anatómicas diferentes en el tracto biliar en pacientes con PDAC. Conclusión: hasta donde sabemos, este es el primer estudio que compara dos ubicaciones anatómicas diferentes sobre el tracto biliar en pacientes con PDAC. Entre los dos grupos de PDAC, la microbiota del sistema de conductos semicerrados del tracto biliar, se encontró una similitud sustancial, reflejada en los índices de diversidad alfa y beta y en abundancias.

Evaluation of three Staphylococcus aureus proteins involved in the adhesion process as antigens for the detection of bovine intramammary infections.

Introduction. Fast and accurate diagnosis is one of the key strategies in the successful control of intramammary infections caused by Staphylococcus aureus. Immunoassays are one of the diagnostic tools that have been proposed for the detection of S. aureus infection because they offer an advantage in terms of cost and are fast and easy to use compared to other diagnostic tests.Gap statement. The main challenge of the immunoassays is to identify antigens or serological markers that allow accurate discrimination between infected and uninfected cows with S. aureus, since this bacterium can naturally colonize different areas of the animal body.Aim. To evaluate three S. aureus proteins (IsdA, ClfA, SdrD) involved in the adhesion process as antigens to detect indicator antibodies of bovine intramammary infections.Methodology. Ninety-six cows in lactation and not vaccinated against S. aureus were included. Forty-eight of these cows were infected with S. aureus, while the rest (n=48 cows) were uninfected. Blood and milk samples were collected from each animal to recover serum and whey. IgG titres against the three proteins individually and combined (Mix) were measured in each sample using an enzyme-linked immunosorbent assay (ELISA) test.Results. Significant differences in the IgG response against the proteins evaluated were observed, highlighting the antigenic potential of IsdA and demonstrating that some antigens can detect specific antibodies of infection better than others. According to receiver operating characteristic (ROC) curve analysis, the combined proteins showed the most remarkable capacity (sensitivity of 79 % and specificity of 77 %) to differentiate between infected and uninfected cows when blood samples were used. In addition, the combined proteins also showed the highest specificity (94 %) when using milk samples.Conclusion. Our findings provide information on the usefulness of three adhesion-associated S. aureus proteins in detecting serological markers of intramammary infections in bovines.

Epidemiological and Molecular Characterization of Blastocystis Infection in Children Attending Daycare Centers in Medellín, Colombia.

BACKGROUND: The present study aims to perform an epidemiological and molecular characterization of Blastocystis infection in a child population attending daycare centers of Medellín, Colombia. METHODS: A total of 265 children aged 0-5 years were enrolled in five children's centers in urban sectors of Medellín, northwestern Colombia. Stool samples were taken to identify intestinal parasites by direct examination, Ritchie-Frick concentration, and molecular identification of Blastocystis by conventional PCR and subtype (ST) identification by PCR barcoding with subsequent phylogenetic reconstruction. Kappa index was calculated to evaluate the agreement between microscopy and PCR for the diagnosis of Blastocystis. RESULTS: The prevalence of intestinal protozoa was 36.6% (97/265), with Blastocystis as the most frequent parasitic protozoan at 15.8% (42/265), followed by Giardia intestinalis at 15.5% (41/265) and Endolimax nana at 15.1% (40/265). The prevalence of Blastocystis by PCR was 53.2% (141/265), the subtypes identified were ST3 at 30.5% (18/59), ST2 at 23.7% (14/59), ST1 at 20.3% (12/59), and with less frequency, ST4 at 5.1% (3/59), ST6 at 1.7% (1/59) and ST16 at 15.3% (9/59) allele 162. CONCLUSION: This study provides the first genetic characterization of Blastocystis subtypes circulating in a population of Medellín, Colombia, and also updates the epidemiology of Blastocystis subtypes in the world with the first identification of ST16 in humans.

Immunoproteomics characterization of Leishmania panamensis proteins for potential clinical diagnosis of mucosal Leishmaniasis.

Diagnosis of leishmaniasis based on antibodies detection represents a challenge due to cross-reaction of sera with other infectious agents, which co-exist in endemic areas of Leishmania sp, especially patients with Trypanosoma cruzi. This work is aimed at searching for immunogenic proteins in sera from patients with cutaneous and mucosal leishmaniasis that may be potential candidates for the development of diagnostic tests and/or vaccines that help control the infection. Total protein extracts of L. panamensis promastigotes were put in contact with sera from patients with cutaneous and mucosal leishmaniasis (immunoblots). Immunoreactive proteins were identified by mass spectrometry and bioinformatics tools. 81 proteins were identified. One of these was uniquely recognized by the sera from patients with ML but not from sera from either CL or Chagas disease patients. MS analysis of this band pointed to the putative leishmanial 3-oxoacyl-(Acylcarrierprotein) reductase.

Primer caso confirmado de brucelosis humana por Brucella melitensis, una zoonosis presente en Colombia / First confirmed case of human brucellosis by Brucella melitensis, a zoonosis present in Colombia

Resumen La brucelosis, principal zoonosis a nivel mundial tiene alta prevalencia en varios países de Latinoamérica. Se asocia con la exposición a ganado infectado por distintas especies del género Brucella. B. melitensis la más virulenta para el humano, causa con frecuencia complicaciones de predominio osteoarticular. En Colombia se cree que la infección por B. melitensis es una entidad ausente, a pesar de su plausibilidad biológica en nuestro contexto; sin embargo, son escasos los estudios sobre su ocurrencia y mínimo el índice de sospecha de la enfermedad, por lo cual creemos está subdiagnosticada. Presentamos el primer caso confirmado de brucelosis por B. melitensis en Colombia en una joven embarazada, con diagnóstico incidental, en quien el análisis retrospectivo de su cuadro clínico alertó sobre puntos clave que pueden impactar en el diagnóstico y tratamiento oportuno de la enfermedad. Se plantean preguntas de prevalencia real de esta entidad en Colombia.

Summary Brucellosis, the principal zoonoses globally is highly prevalent in different countries of Latin America. It is associated with the exposition of livestock infected with different Brucella species, being B. melitensis the most virulent for humans, and frequently causing osteoarticular complications. In Colombia it is believed that B. melitensis infection is an absent entity, despite its biological plausibility in our context; however, there are few studies on its occurrence and a minimum index of suspicion of the disease, which is why we believe it is underdiagnosed. We present the first confirmed case of brucellosis by B. melitensis in Colombia diagnosed in a young pregnant patient, with an incidental diagnosis, in whom a retrospective analysis of her clinical outcome warned of key points that may impact on the diagnosis and timely treatment of the disease. We present several questions surrounding the real prevalence of this entity in Colombia.

Current Advances in the Development of Diagnostic Tests based on Aptamers in Parasitology: A Systematic Review.

Aptamers are single-stranded DNA or RNA sequences of 20-80 nucleotides that interact with different targets such as: proteins, ions, viruses, or toxins, through non-covalent interactions and their unique three-dimensional conformation. They are obtained in vitro by the systematic evolution of ligands by exponential enrichment (SELEX). Because of their ability of target recognition with high specificity and affinity, aptamers are usually compared to antibodies. However, they present many advantages that make them promising molecules for the development of new methods for the diagnosis and treatment of human diseases. In medical parasitology, aptamers also represent an attractive alternative for the implementation of new parasite detection methods, easy to apply in endemic regions. The aim of this study was to describe the current advances in the development of diagnostic tests based on aptamers in parasitology. For this, articles were selected following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, with specific inclusion and exclusion criteria. The 26 resulting articles deal with the use of aptamers for the detection of six important protozoa that affect human health. This systematic review clearly demonstrates the specificity, sensitivity and selectivity of aptamers and aptasensors, that certainly will soon become standard methods in medical parasitology.

Biliary Tract Carcinogenesis Model Based on Bile Metaproteomics.

Purpose: To analyze human and bacteria proteomic profiles in bile, exposed to a tumor vs. non-tumor microenvironment, in order to identify differences between these conditions, which may contribute to a better understanding of pancreatic carcinogenesis. Patients and Methods: Using liquid chromatography and mass spectrometry, human and bacterial proteomic profiles of a total of 20 bile samples (7 from gallstone (GS) patients, and 13 from pancreatic head ductal adenocarcinoma (PDAC) patients) that were collected during surgery and taken directly from the gallbladder, were compared. g:Profiler and KEGG (Kyoto Encyclopedia of Genes and Genomes) Mapper Reconstruct Pathway were used as the main comparative platform focusing on over-represented biological pathways among human proteins and interaction pathways among bacterial proteins. Results: Three bacterial infection pathways were over-represented in the human PDAC group of proteins. IL-8 is the only human protein that coincides in the three pathways and this protein is only present in the PDAC group. Quantitative and qualitative differences in bacterial proteins suggest a dysbiotic microenvironment in the PDAC group, supported by significant participation of antibiotic biosynthesis enzymes. Prokaryotes interaction signaling pathways highlight the presence of zeatin in the GS group and surfactin in the PDAC group, the former in the metabolism of terpenoids and polyketides, and the latter in both metabolisms of terpenoids, polyketides and quorum sensing. Based on our findings, we propose a bacterial-induced carcinogenesis model for the biliary tract. Conclusion: To the best of our knowledge this is the first study with the aim of comparing human and bacterial bile proteins in a tumor vs. non-tumor microenvironment. We proposed a new carcinogenesis model for the biliary tract based on bile metaproteomic findings. Our results suggest that bacteria may be key players in biliary tract carcinogenesis, in a long-lasting dysbiotic and epithelially harmful microenvironment, in which specific bacterial species' biofilm formation is of utmost importance. Our finding should be further explored in future using in vitro and in vivo investigations.

Diagnosis of human and canine Brucella canis infection: development and evaluation of indirect enzyme-linked immunosorbent assays using recombinant Brucella proteins.

Brucella canis, a Gram-negative coccobacilli belonging to the genus Brucellae, is a pathogenic bacterium that can produce infections in dogs and humans. Multiple studies have been carried out to develop diagnostic techniques to detect all zoonotic Brucellae. Diagnosis of Brucella canis infection is challenging due to the lack of highly specific and sensitive diagnostic assays. This work was divided in two phases: in the first one, were identified antigenic proteins in B. canis that could potentially be used for serological diagnosis of brucellosis. Human sera positive for canine brucellosis infection was used to recognize immunoreactive proteins that were then identified by performing 2D-GEL and immunoblot assays. These spots were analyzed using MALDI TOF MS and predicted proteins were identified. Of the 35 protein spots analyzed, 14 proteins were identified and subsequently characterized using bioinformatics, two of this were selected for the next phase. In the second phase, we developed and validated an indirect enzyme-linked immunosorbent assays using those recombinant proteins: inosine 5' phosphate dehydrogenase, pyruvate dehydrogenase E1 subunit beta (PdhB) and elongation factor Tu (Tuf). These genes were PCR-amplified from genomic DNA of B. canis strain Oliveri, cloned, and expressed in Escherichia coli. Recombinant proteins were purified by metal affinity chromatography, and used as antigens in indirect ELISA. Serum samples from healthy and B. canis-infected humans and dogs were used to evaluate the performance of indirect ELISAs. Our results suggest that PdhB and Tuf proteins could be used as antigens for serologic detection of B. canis infection in humans, but not in dogs. The use of recombinant antigens in iELISA assays to detect B. canis-specific antibodies in human serum could be a valuable tool to improve diagnosis of human brucellosis caused by B. canis.

Screening for intestinal parasites in adults from three different regions of Colombia / Tamizaje de parásitos intestinales en adultos de tres regiones de Colombia

Intestinal parasitosis (IP) is a public health problem in developing countries affecting one fourth of the global population. IP are common studied in children, ne glecting the adults that are also at high risk and source of transmission. A screening study was performed with a convenience sample in three Colombian regions: Guachené (Cauca), Quibdó (Chocó), and Urabá (Antioquia). Feces samples from 284 volunteers (older than 18 years old) were tested by microscopy to identify para site ova and cysts. The IP frequency was 14.5%, and 52.1% were males. 63.2% of the parasitized patients exhibited diarrhea, and/or abdominal pain with significant association. 39.5% had single parasitic infection and 60.5% had multiple parasites: Blastocystis hominis (63.9%), Entamoeba hystolitica/dispar (39.4%), Endolimax nana (33.3%), Ascaris lumbricoides (22.2%), Giardia lamblia (19.4%), Entamoeba coli (13.9%), Trichuris trichiura (11.1%), hookworm species (11.1%), Strongyloides stercolaris (5.6%), and Iodamoeba butschlii (2.8%). A multivariate approach was used to determine predictor factors for IP: male gender, rainwater as drinking sour ce, and feces disposal different to toilet, latrine or septic tank were positively associated with infection. This study evidences that adult population, not only children from vulnerable areas of Colombia, must have to include as a risk for intestinal parasitism.

La parasitosis intestinal (PI) es un problema de salud pública en países en desarrollo que afecta un cuarto de la población mundial. Las PI son comúnmente estudia das en niños, olvidando que los adultos están también en riesgo y a su vez pueden ser fuentes de transmisión. Se realizó un estudio de tamizaje con una muestra escogida por conveniencia en tres regiones de Colombia: Guachené (Cauca), Quibdó (Chocó) y Urabá (Antioquia). Las muestras de materia fecal de 284 voluntarios mayores de 18 años, fueron estudiadas por microscopía para identificar parásitos, huevos y quistes. La frecuencia de las PI fue del 14.5%, 52.1% de los positivos fueron hombres. 63.2% de los individuos parasitados tenían asociación significativa con diarrea, y/o dolor abdominal. 39.5% tuvieron infección por un solo parásito y 60.5% fueron positivos para varios parásitos: Blastocystis hominis (63.9%), Entamoeba hystolitica/dispar (39.4%), Endolimax nana (33.3%), Ascaris lumbricoides (22.2%), Giardia lamblia (19.4%), Entamoeba coli (13.9%), Trichuris trichiura (11.1%), Strongyloides stercolaris (5.6%), y Iodamoeba butschlii (2.8%). Se realizó un aná lisis multivariado para determinar factores predictores para PI: el género masculino, el agua lluvia para consumo, y la disposición de excretas diferente a sanitario, letrina o pozo séptico, están asociados positivamente a la PI. Este estudio evidencia que la población adulta, no solo la infantil, residentes en áreas vulnerables de Colombia, deben incluirse como población de riesgo al parasitismo intestinal.

Presencia de Salmonella spp. en tortugas de río en cautiverio y en libertad en Urabá, Colombia / Presence of Salmonella spp in captivity and wild river turtles in Urabá, Colombia / Presença de Salmonella spp. em tartarugas de rio em cativeiro e em liberdade em Urabá, Colômbia

Resumen La salmonelosis es una enfermedad infecciosa de alta prevalencia a nivel mundial en la cual las tortugas han sido reconocidas como portadores crónicos. Diferentes estudios han reportado la presencia de Salmonella spp. en tortugas de río en diferentes países, sin embargo, ha sido poco reportada en individuos en libertad. El objetivo de este estudio fue determinar la presencia de Salmonella spp. en tortugas de río en cautiverio (n= 55) y en libertad (n= 50) en el Urabá antioqueño (Colombia) entre 2015-2016. Se incluyeron las especies Trachemys venusta, Rhinoclemmys melanosterna y Kinosternon leucostomum. Se tomó la muestra de materia fecal por hisopado cloacal, se cultivó y de las colonias aisladas se realizó extracción de ADN y reacción en cadena de polimerasa (PCR). De la población muestreada (n=105) se encontraron dos individuos positivos a Salmonella spp., ambos en cautiverio, machos, adultos y pertenecientes a la especie R. melanosterna. Los resultados obtenidos no excluyen la posibilidad de infección debido a la intermitencia en la excreción de la bacteria en heces. Esta investigación aporta evidencia a la presencia de la bacteria en las tortugas de la región de estudio y la necesidad de implementar medidas preventivas que disminuyan el contacto con estas especies, y por lo tanto la probabilidad de transmisión de salmonelosis no tifoidea en la población humana de la región.

Abstract Salmonellosis is a high prevalence infectious diseases worldwide and turties have been recognized as chronic carriers. Studies have reported the presence of Salmonella spp in river turtles in different countries; however, studies in wild individuals are less common. The objective of this study was to identify the presence of Salmonella spp in wild (n=50) and in captivity (n=55) river turtles in Uraba Antioqueño (Colombia) between 201 5-2016. Trachemys venusta, Rhinoclemmys melanosterna, and Kinosternon leucosto-mum were included. Feces samples were taken by cloaca swab׳ cultures were performed, and DNA extraction and PCR were made from the colonies isolated. From total population(n=105) two male, adults in captivity were positive, the specie was R. melanosterna. The results obtained do not exclude infection due to the intermittence in the excretion of the bacteria in feces. This research provides evidence of the presence of the bacteria in turtles from the region and highlights the requirement to implement preventive activities to reduce contact with these species, and decrease the probability of transmission of nontyphoidal salmonellosis in human population around the region.

Resumo Salmonelose é uma doença de alta prevalência mundial. As tartarugas são reconhecidas como portadoras crônicas. Em diferentes países tem sido relatado a presença de Salmonella spp. em tartarugas de rios embora, poucos são os estudos em indivíduos selvagens. O objetivo deste estudo foi identificar na região do Urabá Antioqueño (Colombia) nos anos 2015 e 2016 a presença de Salmonella spp. em tartarugas selvagens (n = 50) e em cativeiro (n = 55). Foram incluídas tartarugas das espécies Trachemys venusta, Rhinoclemmys melanosterna e Kinosternon leucostomum. Foi coletada por esfregaço cloacal e para cultura uma amostra de fezes. A partir das colônias isoladas foi realizada extração de DNA para testes moleculares (PCR). Da população total (n = 105) foram positivos do grupo de cativeiro dois machos adultos da espécie R. melanosterna. Devido à intermitência na excreção das bactérias nas fezes os resultados obtidos não excluem a infecção. Esta pesquisa fornece evidências da presença da bactéria em tartarugas da região do Urabá e destaca a necessidade de implementar atividades preventivas para reduzir o contato com essas espécies selvagens e diminuir a probabilidade de transmissão zoonótica de salmonelose não tifoidal na população humana da região.

Detection of Salmonella human carriers in Colombian outbreak areas.

INTRODUCTION: Salmonellosis, a zoonotic and foodborne disease, is a public health problem in developing countries. With the aim of identifying human carriers of Salmonella, a survey was performed in five regions of Colombia with reported salmonellosis outbreaks. METHODOLOGY: The general population and cholecystectomy surgical patients were included in this study. Stool samples from 667 volunteers and gallbladder bile samples from 199 surgical patients were examined. Detection of Salmonella from cultured stool and bile samples was determined by polymerase chain reaction (PCR). Multiplex PCR and biochemical and serological tests were performed to identify the serovars of the isolates. RESULTS: Nine (1.35%) stool samples were positive for Salmonella: two S. Newport, two S. Anatum, one S. Sinstorf, and four Salmonella spp. A total of 11 gallbladder bile samples were positive: S. Enteritidis was isolated from 3 bile cultures (1.5%), and 8 samples (4%) were positive for Salmonella spp. CONCLUSIONS: Our results show the presence of Salmonella carriers in the inhabitants of regions with reported outbreaks and suggest that these carriers are potential sources of infection in endemic and epidemic cases. Carriers also suggest Salmonella zoonotic transmission, since broiler and beef cattle are hosts to the Salmonella serotypes isolated. It is important to establish the source of infection in regions where salmonellosis is endemic in order to control transmission.

Gallbladder microbiota variability in Colombian gallstones patients.

INTRODUCTION: Gallbladder stones are a very frequently occurring condition. Despite bile bactericidal activity, many bacteria have been detected inside the gallbladder, and gallstones facilitate their presence. Between 3% and 5% of the patients with Salmonella spp. infection develop the carrier stage, with the bacteria persisting inside the gallbladder, shedding bacteria in their feces without signs of infection. The aim of this study was to isolate bacteria from Colombian patients with gallstones, using standard culturing methods, and to identify Salmonella spp. carriers by molecular techniques. METHODOLOGY: A total of 149 patients (120 female and 29 male) diagnosed with gallstones who underwent cholecystectomy and who did not have symptoms of acute inflammation were included. Gallbladder tissue and bile were cultured and used for DNA extraction and Salmonella spp. hilA gene detection. RESULTS: Of the 149 patients 28 (19%) had positive cultures. Twenty-one (75%) patients with positive cultures were from Medellin's metropolitan area. In this geographical location, the most frequent isolations were Pseudomonas spp. (38%), Klebsiella spp. (23%), and Proteus spp. (9%) in addition to unique cases of other bacteria. In Apartado, the isolates found were Enterobacter cloacae (50%), Raoultella terrigena (32%), and both Enterobacter cloacae and Raoultella terrigena were isolated in one (18%) male patient. Five (3.3%) of the 149 patients had positive polymerase chain reaction (PCR) results for the hilA gene of Salmonella spp., all of whom were female and residents of the Medellín metropolitan area. CONCLUSIONS: The gallbladder microbiota variability found could be related to geographical, ethnic, and environmental conditions.

Conocimiento de la microbiota de la cavidad oral a través de la metagenómica / Knowledge of the microbiota of the oral cavity through the metagenomic

La microbiota oral es uno de los ecosistemas microbianos más antiguos en ser reconocido, y su descripción inicia en 1863 cuando Anton van Leeuwenhoek observa por primera vez en el microscopio a estos microorganismos en placas dentales. En la actualidad, las técnicas de secuenciación y el análisis del genoma a gran escala ha permitido construir bases de datos genómicas, realizar linajes microbianos específicos y conocer que no solamente hacen parte de la microbiota oral humana unos 600 o 700 taxones, sino que se estima que el número de filotipos podrían estar en alrededor de 19000. Todo este conocimiento es una herramienta valiosa para la identificación correcta de las bacterias que están involucradas en complejas biopelículas orales y nos facilitaría así comprender su potencial genético. Además, nos permitiría entender y dilucidar mejor la patología oral, y conocer si los cambios que predisponen a la enfermedad ocurren primero en el huésped o por el contrario a nivel microbiano. En conclusión, el estudio del metagenoma de la microbiota no solo de la cavidad oral es clave para la creación de herramientas diagnósticas y terapéuticas que repercutirán en la calidad de vida de los pacientes. Esta revisión pone en contexto lo que se ha publicado en los últimos años en este tema.

The oral microbiota is one of the oldest microbial ecosystems recognized. The oral microbiota description began in 1863 when Anton van Leeuwenhoek observed, using the microscope, microorganisms in dental plaque. Recently, DNA sequencing and genome analysis have allowed researchers to build large-scale genomic databases, characterize specific microbial lineages, and discover that the human oral microbiota is compose by approximately 600 to 700 taxa and 19000 phylotypes. All this knowledge is a valuable tool for the precise identification of the bacteria that are involved in complex oral biofilms. In addition, the characterization of oral microbiota will allow us to understand different oral pathologies, and to know whether changes that predispose to a disease, occur first in the host or conversely at the microbial level. In conclusion, the study of the metagenome of the oral cavity microbiota is key to develop new diagnostic and therapeutic tools that will improve the quality of the patients life. This review puts into context what has been published in recent years on this subject.

Comparison of Brucella canis genomes isolated from different countries shows multiple variable regions.

Brucella canis is a pathogenic bacterium for dogs and its zoonotic potential has been increasing in recent years. In this study, we report the sequencing, annotation and analysis of the genome of Brucella canis strain Oliveri isolated from a dog in a breeding kennel in Medellín, Colombia, South America. Whole genome shotgun sequencing was carried out using the ROCHE 454 GS FLX Titanium technology at the National Center for Genomic Sequencing-CNSG in Medellin, Colombia. The assembly procedure was performed using Newbler v2.6. In the genome annotation process, each contig was analyzed independently using as reference Brucella suis ATCC 1330 chromosomes. This new genome could be useful for the development of diagnostic tools and for vaccines search as well, in order to reduce the health impact of this infection in both, dogs and humans. The sequence was deposited in EMBL-EBI with accession numbers HG803175 and HG803176 for chromosomes 1 and 2, respectively.

Application of a polymerase chain reaction test for the detection of Brucella canis from clinical samples of canines and humans / Aplicación de una prueba de reacción en cadena de la polimerasa para detección de Brucella canis a partir de muestras clínicas de caninos y humanos / Aplicação de um teste de reacção em cadeia da polimerase para detecção de Brucella canis a partir de amostras clínicas de canino e humano

Background: laboratory diagnosis of canine brucellosis includes serological and bacteriological tests; the blood culture is considered the gold standard, but it presents issues of sensitivity and delay in results. Therefore, the polymerase chain reaction (PCR) could be useful to detect low amounts of bacterial DNA from clinical samples and provide results within hours. Objective: to evaluate the sensitivity and specificity of PCR for the detection of Brucella canis in whole blood samples. Methods: blood samples from 499 dogs from kennels in two Colombian regions and 91 co-inhabiting humans were used. The 2-mercaptoethanol rapid slide agglutination test (2ME-RSAT) from serum and blood culture and PCR tests from whole blood were performed on all samples. Bayes theorem was used to establish the sensitivity and specificity of the PCR test compared with the other tests performed. Results: 9.9% of the evaluated co-inhabiting humans yielded positive serological results and 0% were positive by PCR or blood culture tests. 10.8% of dog samples were positive by blood culture, 19% were positive by PCR and 13% were positive by 2ME-RSAT. 7% of the samples were positive by all tests. Compared with blood culture, PCR had a sensitivity of 92.6% and a specificity of 90% for canine samples. Compared with 2ME-RSAT, it had a sensitivity of 77.4% and a specificity of 89.2%. When PCR and 2ME-RSAT results were compared with blood culture, a higher number of positive samples were retrieved than when results of only individual tests were applied. Conclusions: PCR is useful to detect B. canis in clinical samples; however, it is preferable to include the 2ME-RSAT test, as this improves the accuracy of the diagnosis. The PCR results are obtained within 24 to 48 hours and do not require the presence of whole bacterial cells to detect DNA.

Antecedentes: el diagnóstico de laboratorio de brucelosis canina incluye pruebas serológicas y bacteriológicas. El hemocultivo se considera el estándar de oro, pero tiene problemas de sensibilidad y tiempo de entrega de los resultados. Por eso, la reacción en cadena de la polimerasa (PCR) podría ser útil para detectar pequeñas cantidades de ADN bacteriano de muestras clínicas y proporcionar resultados en horas. Objetivo: evaluar la sensibilidad y especificidad de una PCR para la detección de Brucella canis, en muestras de sangre total de 499 perros de perreras y 91 humanos cohabitantes de dos regiones de Colombia. Métodos: se realizaron pruebas de aglutinación rápida en placa con 2-mercaptoetanol (2ME-PARP) a partir de suero, PCR y hemocultivo a partir de sangre total. El teorema de Bayes se utilizó para establecer la sensibilidad y especificidad de la prueba de PCR respecto a las demás. Resultados: 9,9% de los humanos cohabitantes evaluados resultaron positivos para la prueba serológica, y el 0% fue positivo para PCR o hemocultivo. 10,8% de las muestras de perros fueron positivas para hemocultivo, 19% fueron positivas para PCR y 13% eran 2ME-PARP positivo. 7% de las muestras fueron positivas para todos los ensayos. En las muestras caninas, la PCR tuvo una sensibilidad del 92,6% y una especificidad del 90% en comparación con el hemocultivo. En comparación con 2ME-PARP, tuvo una sensibilidad del 77,4% y una especificidad del 89,2%. Cuando se compararon los resultados de la PCR y 2ME-PARP con el hemocultivo, un mayor número de muestras positivas fueron obtenidas que usando los resultados de cada una. Conclusiones: la PCR es útil para detectar B.canis en muestras clínicas, sin embargo, es recomendable incluir la prueba de 2ME-PARP, lo que mejora la exactitud del diagnóstico, se obtienen los resultados en 24 ó 48 horas y no requieren la presencia de células bacterianas completas para detectar ADN.

Antecedentes: o diagnóstico laboratorial da brucelose canina inclui testes sorológicos e bacteriológicos. O padrão ouro é a cultura de sangue, mas tem problemas com a sensibilidade e o tempo de entrega dos resultados. Por conseguinte, a reação em cadeia da polimerase (PCR), pode ser útil para detectar pequenas quantidades de ADN bacteriano diretamente a partir de amostras clínicas e fornecem resultados em 24 horas. Objetivo: para avaliar a sensibilidade e a especificidade da PCR para a detecção de Brucella canis em amostras de sangue total de 499 caninos provenientes de canis e 91 seres humanos em contato com estes cães em duas regiões da Colômbia. Métodos: foram realizados testes de aglutinação rápida em placa com 2-mercaptoetanol (2ME-PARP) a partir de soro, PCR y hemocultura a partir de sangue total. O teorema de Bayes utilizou-se para estabelecer a sensibilidade e especificidade da PCR em relação aos outros. Resultados: 9,9% (9) dos humanos avaliados resultaram positivos na prova sorológica, 100% foram negativos por PCR e hemocultura. 10.8% (54) das amostras de cães foram positivas na hemocultura, 19% (95) foram positivas na PCR e 13% (65) foram positivas no teste 2ME-PARP. 7% (35) das amostras foram positivas para todos os testes. Nas amostras caninas, a PCR teve sensibilidade do 92.6% e uma especificidade de 90% em comparação com a hemocultura. Em comparação com 2ME-PARP, teve uma sensibilidade de 77.4% e uma especificidade de 82.2%. Quando foram comparados os resultados da PCR e 2-ME-PARP com a hemocultura, um maior número de amostras positivas foram obtidas que quando foram usados os resultados de cada uma. Conclusões: a PCR é útil para detectar B. canis em amostras clínicas, porém, é recomendável incluir o teste de 2ME-PARP, para melhorar a acurácia do diagnóstico. Os resultados obtém-se em 24-48 horas e não requerem a presença de células bacterianas completas para detectar ADN.

Infección por Brucella canis en humanos: propuesta de un modelo teórico de infección a través de la ruta oral / Brucella canis infection in humans: Proposal of a theoretical model of infection through the oral route

La infección por Brucella canis en los humanos se ha reconocido recientemente como una zoonosis, pero frecuentemente es sub reportada debido a que los síntomas pueden confundirse con los de un resfriado común u otras infecciones causadas por otros patógenos. Los caninos son los hospederos primarios de Brucella canis ; el incremento en la tendencia de tener perros como mascotas podría también aumentar la posibilidad de transmisión de la infección a los humanos por el estrecho contacto entre la mascota infectada y su propietario. En Colombia, hay reportes de aislamientos de B. canis de caninos de criaderos y de un humano en contacto con perros infectados, al igual que reportes de caninos seropositivos a la infección. Sin embargo, no hay mucha información disponible sobre los mecanismos de interacción hospedero-patógeno que conduzcan al establecimiento de la infección por Brucella canis en perros y en humanos esta información es todavía menor. En esta revisión se propone un modelo para la infección humana con Brucella canis a través de la ruta oral utilizando la información disponible para otras especies de Brucella que infectan al humano, incluyendo B. abortu s y B. melitensis , que difieren de B. canis en la composición estructural de su lipopolisacárido. También se hipotetiza el mecanismo de infección celular que es usado por B. canis para invadir y establecer la infección en células no fagocíticas y fagocíticas.

Brucella canis infection in humans has recently been recognized as a zoonosis, but it is frequently under reported because the flu-like symptoms are often confused with the presence of other disease-causing pathogens. Dogs are the primary hosts for Brucella canis ; the increasing trend to adopt dogs as pets also enhances the likelihood of transmission of Brucella canis infection through contact between infected dogs and owners. In Colombia, there are reports of isolates of B. canis from kennel dogs and also from one human being along with seropositive results from dogs and humans. However, the mechanism of hostpathogen interactions leading to the infection of Brucella canis in dogs is still unknown and even less is known about human infections. This review proposes a model for human infection with Brucella canis through the oral route. We use the information available for other human-infecting Brucella species, including B. abortu s and B. melitensis, which differ from B. canis in the structural composition of the lipopolysaccharide molecule. The mechanism of cellular infection used by B. canis to invade and establish infection in nonphagocytic and phagocytic cells is also hypothesized.

[Factors associated with Brucella canis seropositivity in kennels of two regions of Antioquia, Colombia]. / Factores asociados con la seropositividad a Brucella canis en criaderos caninos de dos regiones de Antioquia, Colombia.

The objectives of this study were to determine Brucella canis seroprevalence in dogs and in humans living near kennels and to explore risk factors associated with seropositivity. Twenty kennels were included in a serological survey with RSAT-2ME, and samples were collected from 428 dogs and 91 humans. An interview was applied to determine risk factors, and the data were analyzed using logistic regression. Seroprevalence was 15% in dogs and 9% in humans. Factors associated with current canine seropositivity were: history of canine seropositivity, non-culling of seropositive dogs, history of abortion, poor hygiene and personal protection during reproductive service, and unsafe procedures during care for abortions. Protective factors included: rural location of kennels, ease of cleaning kennels, pre-mating RSAT-2ME, and safe procedures during care for delivery. Factors associated with seropositive status in humans were: kennels located in Valle de Aburrá and urban location.