Sistema de Gestión del Conocimiento ANLIS MALBRÁN
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Survival of an epidemic MDR strain of Mycobacterium tuberculosis and its non-prosperous variant within activated macrophages
No full textFil: Yokobori, Noemi. Instituto de Medicina Experimental (IMEX)-CONICET-Academia Nacional de Medicina, Pacheco de Melo 3081, C1425AUM Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires; Argentina.Fil: Monteserin, Johana. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Rearte, Bárbara. Instituto de Medicina Experimental (IMEX)-CONICET-Academia Nacional de Medicina, Pacheco de Melo 3081, C1425AUM Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires; Argentina.Fil: Paul, Roxana. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Simboli, Norberto. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: López, Beatriz. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Ritacco, Viviana. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Sasiain, María Del Carmen. Instituto de Medicina Experimental (IMEX)-CONICET-Academia Nacional de Medicina, Pacheco de Melo 3081, C1425AUM Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires; Argentina.The fitness of a pathogen results from the interaction of multiple factors favoring either epidemiological success or failure. Herein, we studied the performance of the M strain, a highly successful multidrug resistant Mycobacterium tuberculosis genotype, and its non-prosperous variant, the 410 strain, in activated human monocyte-derived macrophages. Both strains showed comparable ability to induce necrotic cell death and to survive in apoptotic macrophages. Of the various macrophage activation conditions tested, none led to an enhanced control of the outbreak strain. The combination of 1,25(OH)2 vitaminD3 and IFN-γ favored significantly the control of the non-prosperous 410 strain. These observations indicate that the ability of the M strain to survive within the hostile intracellular milieu is conserved, and the overall fitness cost paid by this genotype would be low. Our results provide additional evidence on bacterial traits that may have contributed to the epidemiological success of the M strain
Development and validation of an extended database for yeast identification by MALDI-TOF MS in Argentina
No full textMatrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) has revolutionized the identification of microorganisms in clinical laboratories because it is rapid, relatively simple to use, accurate, and can be used for a wide number of microorganisms. Several studies have demonstrated the utility of this technique in the identification of yeasts; however, its performance is usually improved by the extension of the database. Here we developed an in-house database of 143 strains belonging to 42 yeast species in the MALDI Biotyper platform, and we validated the extended database with 388 regional strains and 15 reference strains belonging to 55 yeast species. We also performed an intra- and interlaboratory study to assess reproducibility and analyzed the use of the cutoff values of 1.700 and 2.000 to correctly identify at species level. The creation of an in-house database that extended the manufacturer's database was successful in view of no incorrect identification was introduced. The best performance was observed by using the extended database and a cutoff value of 1.700 with a sensitivity of .94 and specificity of .96. A reproducibility study showed utility to detect deviations and could be used for external quality control. The extended database was able to differentiate closely related species and it has potential in distinguishing the molecular genotypes of Cryptococcus neoformans and Cryptococcus gattii
Experimental combination therapy using low doses of benznidazole and allopurinol in mouse models of Trypanosoma cruzi chronic infection
No full textThis study evaluated the effectiveness of low doses of benznidazole (BNZ) on continuous administration (BNZc), combined with allopurinol (ALO), in C57BL/6J and C3H/HeN mice infected with Trypanosoma cruzi Nicaragua strain and T. cruzi Sylvio-X10/4 clone. TcN-C57BL/6J was also treated with intermittent doses of BNZ (BNZit). The drug therapy started 3 months post infection (pi) in the chronic phase of mice with heart disease progression, followed-up at 6 months pi. TcN-C57BL/6J treated with BNZc was also monitored up to 12 months pi by serology and electrocardiogram. These mice showed severe electrical abnormalities, which were not observed after BNZc or BNZit. ALO only showed positive interaction with the lowest dose of BNZ. A clear parasitic effect, with significant reductions in antibody titres and parasitic loads, was achieved in all models with low doses of BNZ, and a 25% reduction of the conventional dose showed more efficacy to inhibit the development of the pathology. However, BNZ 75 showed partial efficacy in the TcSylvio-X10/4-C3H/HeN model. In our experimental designs, C57BL/6J allowed to clearly define a chronic phase, and through reproducible efficacy indicators, it can be considered a good preclinical model
A novel pathogenic frameshift variant of KAT6B identified by clinical exome sequencing in a newborn with the Say-Barber-Biesecker-Young-Simpson syndrome
No full textFil: Mendez, Rodrigo. ANLIS Dr. C. G. Malbrán. Centro Nacional de Genética Médica (CeNaGeM). Departamento de medicina genética; Argentina.Fil: Delea, Marisol. ANLIS Dr. C. G. Malbrán. Centro Nacional de Genética Médica (CeNaGeM). Departamento de genética médica; Argentina.Fil: Dain, Liliana. ANLIS Dr. C. G. Malbrán. Centro Nacional de Genética Médica (CeNaGeM). Departamento de genética molecular; Argentina.Fil: Rittler, Mónica. Hospital Materno Infantil "Ramón Sardá". Departamento de medicina genética; Argentina
Coccidioidomycosis in Latin America
No full textFil: Canteros, Cristina. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Servicio Micosis Profundas; Argentina.Fil: Muñiz-Salazar, Raquel. Universidad Autónoma de Baja California. Escuela de Ciencias de la Salud; México.Fil: Rendon, Adrián. Universidad Autónoma de Nuevo León. Hospital Universitario de Monterrey; México.Fil: Arathoon, Eduardo G. Hospital General San Juan de Dios. Asociación de Salud Integral; Guatemala.Fil: Laniado-Laborín, Rafael. Universdad Autónoma de Baja California. Facultad de Medicina y Psicología; México.Coccidioidomycosis is a highly prevalent systemic mycosis in Latin America and has been reported (human and zoonotic cases) in México, Guatemala, Honduras, Colombia, Venezuela, Brazil, Paraguay, Bolivia, and Argentina. The incidence of coccidioidomycosis in Latin America is unknown due to lack of clinical awareness and limited access to laboratory diagnosis. Coccidioidomycosis is as prevalent in Mexico as in the endemic regions of the United States. The number of cases reported in Brazil and Argentina has progressively increased during the last decade, including areas that were not considered as endemic. Genetic studies have shown that the prevalent species in Latin America is Coccidioides posadasii. Coccidioides immitis has been reported sporadically in indigenous cases from Mexico and Colombia. Coccidioidomycosis and tuberculosis share some risk factors such as immunosuppression and residing in areas endemic for these conditions, so their coexistence in the same patient is not uncommon in Latin America. In most regions, clinical diagnosis of coccidioidomycosis is based on direct sputum examination and histopathology results from biopsies or autopsies. This would explain why primary coccidioidomycosis is rarely diagnosed, and most cases published are about chronic pulmonary or disseminated disease
Study on the obtaining of Tityus trivittatus venom in Argentina
No full textFil: de Roodt, Adolfo Rafael. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Producción de Biológicos. Servicio antígenos y antisueros; Argentina.Fil: Lanari, Laura Cecilia. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Producción de Biológicos. Servicio antígenos y antisueros; Argentina.Fil: Laskowicz, Rodrigo Daniel. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Producción de Biológicos. Servicio antígenos y antisueros; Argentina.Fil: Costa de Oliveira, Vanessa. Primera Cátedra de Toxicología, Facultad de Medicina, Universidad de Buenos Aires, Argentina; Laboratorio de Toxinopatología, Centro de Patología Experimental y Aplicada, Facultad de Medicina, Universidad de Buenos Aires; Argentina.Fil: Litwin, Silvana. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Producción de Biológicos; Argentina.Fil: Calderon, Leandro. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Producción de Biológicos; Argentina.Fil: Damin, Carlos Fabián. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Producción de Biológicos; Argentina.Fil: Dokmetjian, Christian. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Producción de Biológicos; Argentina.Fil: Dolab, Jorge A. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Producción de Biológicos; Argentina.Fil: Lago, Néstor Rubén. Laboratorio de Toxinopatología, Centro de Patología Experimental y Aplicada, Facultad de Medicina, Universidad de Buenos Aires; Argentina.Fil: Lértora, Emiliano. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Producción de Biológicos; Argentina.Envenomation by scorpions of the genus Tityus is an important public health problem in Argentina, involving near 8000 stings and 2 deaths each year. Treatment for envenomation is the use of specific antivenom and intensive hospital care. Antivenom is produced by the Ministry of Health and freely distributed throughout the country. For antivenom production it is necessary to collect scorpion venom, which is a difficult task because although scorpions can be found in Argentina, they are less abundant than in warmer latitudes. For this reason venom collection constitutes a bottleneck for antivenom production. Although in Argentina several species of Tityus can be found, most of the accidents are caused by Tityus trivittatus, and the venom of this scorpion has historically been the venom used for antivenom production. We analyzed retrospectively 26 pools of telson homogenates (6964 telsons) and 37 pools of milked venom obtained by electrical stimulation (equivalent to 6841 milkings). Lethal potencies of samples from different provinces were very similar, although venom from scorpions of Buenos Aires city showed the lowest potency. The venom obtained by milking (median LD50 12.3 μg), provided batches containing LD50s more potent when compared with the venom obtained from telson homogenates (p < 0.0001). Many batches of telson homogenates (30%) showed lower potencies than acceptable for antivenom production and control. In addition to the study of the venom yield, the records of immunization of horses, the potency of the batches and the protein content of each batch of anti-scorpion antivenom produced were analyzed, comparing those produced using milked venom with those using telson homogenates as immunogens. Batches produced using milked venom required a shorter period of immunization (p < 0.0001), rendered higher neutralizing titers (p 0.0350) and possessed lower protein content (p 0.0092). Results clearly showed that the milking of scorpions is a more efficient tool to obtain venom for antivenom production in comparison to the use of telson homogenates
Frequency, characterization and genotypic analysis of Shiga toxin-producing Escherichia coli in beef slaughterhouses of Argentina
No full textThe objectives of this study were: (1) to estimate STEC frequency in hide and carcass samples taken from beef slaughterhouses supplying the domestic market in Argentina, (2) to establish the pheno-genotypic characteristics of STEC and non-toxigenic Escherichia coli of serogroups O26, O45, O103, O121, O111, O145 or O157 isolated from the analyzed samples and, (3) to study their clonal relatedness. Sixty hides and 60 carcasses were analyzed. At the screening step, 48% of hide and 80% of carcass samples tested positive for the stx gene by endpoint PCR. The STEC isolation rate was 5% for hides and 8% for carcasses. The isolation rate of STEC-positive for O26, O45, O103, O111, O145 or O157 serogroups was 0% for hides and 2% for carcasses. With the purpose of studying the clonal relatedness of isolates, macrorestriction fragment analysis by pulsed-field gel electrophoresis was performed. The results indicated cross-contamination between hides and between carcasses of animals in the same lot and, that the origin of carcass contamination was their own hide, or the hides of other animals in the same lot. The high detection rate at the screening step, especially in carcasses, and the evidence of cross-contamination show the need to apply additional in-plant intervention strategies aimed at preventing carcass contamination
Optimization of DNA Extraction from Individual Sand Flies for PCR Amplification
No full textFil: Caligiuri, Lorena G. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro Regional de Estudios Genómicos; Argentina.Fil: Sandoval, Adolfo E. Municipalidad de Posadas. Secretaría de Calidad de Vida. Laboratorio de Vectores, Posadas, Misiones; Argentina.Fil: Miranda, Jose C. Fundação Oswaldo Cruz. Instituto Gonçalo Moniz, Salvador, Bahía; Brasil.Fil: Pessoa, Felipe A. Fundação Oswaldo Cruz. Instituto Leonidas e Maria Deane, Manaos, Amazonas; Brasil.Fil: Santini, María Soledad. ANLIS Dr.C.G.Malbrán. Centro Nacional de Diagnóstico e Investigación en Endemo Epidemias; Argentina.Fil: Salomón, Oscar Daniel. Ministerio de Salud de la Nación. Instituto Nacional de Medicina Tropical, Puerto Iguazú, Misiones; Argentina.Fil: Secundino, Nagila F. C. Fundação Oswaldo Cruz. René Rachou Research Institute. Laboratory of Medical Entomology; Minas Gerais; Brasil.Fil: McCarthy, Christina B. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro Regional de Estudios Genómicos; Argentina.Numerous protocols have been published for extracting DNA from phlebotomines. Nevertheless, their small size is generally an issue in terms of yield, efficiency, and purity, for large-scale individual sand fly DNA extractions when using traditional methods. Even though this can be circumvented with commercial kits, these are generally cost-prohibitive for developing countries. We encountered these limitations when analyzing field-collected Lutzomyia spp. by polymerase chain reaction (PCR) and, for this reason, we evaluated various modifications on a previously published protocol, the most significant of which was a different lysis buffer that contained Ca2+ (buffer TESCa). This ion protects proteinase K against autolysis, increases its thermal stability, and could have a regulatory function for its substrate-binding site. Individual sand fly DNA extraction success was confirmed by amplification reactions using internal control primers that amplify a fragment of the cacophony gene. To the best of our knowledge, this is the first time a lysis buffer containing Ca2+ has been reported for the extraction of DNA from sand flies
Acute disseminated encephalomyelitis due to Mycoplasma pneumoniae in a previously healthy boy
No full textFil: Cadario, María Estela. ANLIS Dr. C. G. Malbrán. Instituto Nacional de Enfermedades Infecciosas (INEI); Argentina.Fil: Ellis, Alejandro. Sanatorio Mater Dei. Servicio de pediatría; Argentina.Fil: Garea, Mónica. Sanatorio Mater Dei. Servicio de pediatría; Argentina.Fil: Cairnie, Antonio. Sanatorio Mater Dei. Servicio de pediatría; Argentina.Fil: Mistchenko, Alicia. Hospital de niños "Dr. Ricardo Gutiérrez". Servicio de virología; Argentina.Fil: García Roig, Cristian. Sanatorio Mater Dei. Servicio de pediatría; Argentina.Fil: Freire, María Cecilia. ANLIS Dr. C. G. Malbrán. Instituto Nacional de Enfermedades Infecciosas (INEI); Argentina.Fil: Savy, Vilma. ANLIS Dr. C. G. Malbrán. Instituto Nacional de Enfermedades Infecciosas (INEI); Argentina.Fil: Sciarrotta, Juan Antonio. Sanatorio Mater Dei. Servicio de pediatría; Argentina.We present here the case of a previously healthy 5 year-old boy hospitalized in an intensive care unit due to tonic-clonic seizures focused on the face and right side of the body, and axillary temperature of 37.4°C. Common bacterial and viral etiology was ruled out through studies of cerebrospinal fluid (CSF) samples. Mycoplasma pneumoniae was suspected by a positive immunofluorescence serum test for IgM class antibodies. Finally, with a brain biopsy, M. pneumoniae was confirmed by polymerase chain reaction (PCR) and acute disseminated encephalomyelitis by pathological anatomy. The patient was treated with clarithromycin and had an uneventful evolution. At least to our knowledge, this is the first case in which M. pneumoniae DNA was detected by PCR in a brain biopsy
The epidemiological signature of influenza B virus and its B/Victoria and B/Yamagata lineages in the 21st century
Get PDFWe describe the epidemiological characteristics, pattern of circulation, and geographical distribution of influenza B viruses and its lineages using data from the Global Influenza B Study. We included over 1.8 million influenza cases occurred in thirty-one countries during 2000-2018. We calculated the proportion of cases caused by influenza B and its lineages; determined the timing of influenza A and B epidemics; compared the age distribution of B/Victoria and B/Yamagata cases; and evaluated the frequency of lineage-level mismatch for the trivalent vaccine. The median proportion of influenza cases caused by influenza B virus was 23.4%, with a tendency (borderline statistical significance, p = 0.060) to be higher in tropical vs. temperate countries. Influenza B was the dominant virus type in about one every seven seasons. In temperate countries, influenza B epidemics occurred on average three weeks later than influenza A epidemics; no consistent pattern emerged in the tropics. The two B lineages caused a comparable proportion of influenza B cases globally, however the B/Yamagata was more frequent in temperate countries, and the B/Victoria in the tropics (p = 0.048). B/Yamagata patients were significantly older than B/Victoria patients in almost all countries. A lineage-level vaccine mismatch was observed in over 40% of seasons in temperate countries and in 30% of seasons in the tropics. The type B virus caused a substantial proportion of influenza infections globally in the 21st century, and its two virus lineages differed in terms of age and geographical distribution of patients. These findings will help inform health policy decisions aiming to reduce disease burden associated with seasonal influenza