Evolution of SARS-CoV-2 during the first year of the COVID-19 pandemic in Northwestern Argentina.

Studies about the evolution of SARS-CoV-2 lineages in different backgrounds such as naive populations are still scarce, especially from South America. This work aimed to study the introduction and diversification pattern of SARS-CoV-2 during the first year of the COVID-19 pandemic in the Northwestern Argentina (NWA) region and to analyze the evolutionary dynamics of the main lineages found. In this study, we analyzed a total of 260 SARS-CoV-2 whole-genome sequences from Argentina, belonging to the Provinces of Jujuy, Salta, and Tucumán, from March 31st, 2020, to May 22nd, 2021, which covered the full first wave and the early second wave of the COVID-19 pandemic in Argentina. In the first wave, eight lineages were identified: B.1.499 (76.9%), followed by N.5 (10.2%), B.1.1.274 (3.7%), B.1.1.348 (3.7%), B.1 (2.8%), B.1.600 (0.9%), B.1.1.33 (0.9%) and N.3 (0.9%). During the early second wave, the first-wave lineages were displaced by the introduction of variants of concern (VOC) (Alpha, Gamma), or variants of interest (VOI) (Lambda, Zeta, Epsilon) and other lineages with more limited distribution. Phylodynamic analyses of the B.1.499 and N.5, the two most prevalent lineages in the NWA, revealed that the rate of evolution of lineage N.5 (7.9 × 10-4 substitutions per site per year, s/s/y) was a ∼40% faster than that of lineage B.1.499 (5.6 × 10-4 s/s/y), although both are in the same order of magnitude than other non-VOC lineages. No mutations associated with a biological characteristic of importance were observed as signatures markers of the phylogenetic groups established in Northwestern Argentina, however, single sequences in non-VOC lineages did present mutations of biological importance or associated with VOCs as sporadic events, showing that many of these mutations could emerge from circulation in the general population. This study contributed to the knowledge about the evolution of SARS-CoV-2 in a pre-vaccination and without post-exposure immunization period.

Human Monkeypox in People With HIV: Transmission, Clinical Features, and Outcome.

We describe the first 25 persons with HIV diagnosed with human monkeypox virus (MPXV) in our hospital in an ongoing outbreak in Spain. Proctitis was the predominant finding in 52%, and MPXV DNA was detected in rectal swabs from 90%. Proctitis and demonstration of MPXV in rectal swabs support the sexual transmission of MPXV.

[Detection of human bocavirus in children from Tucuman and Santa Fe, Argentina]. / Detección de bocavirus humano en la población infantil de Tucumán y Santa Fe, Argentina.

BACKGROUND: A large proportion of acute respiratory tract infections (ARTI) remain without etiologic diagnosis, reason why new pathogens are investigated continuously. Human bocavirus (HBoV) was discovered in 2005, as a new member of Parvoviridae family and proposed to cause ARTI. AIM: To know the prevalence of HBoV among pediatric populations hospitalized for ARTI in two provinces of Argentina: Santa Fe and Tucuman; and to describe epidemiological and clinical aspects associated to its detection. MATERIALS AND METHODS: We studied nasopharyn-geal aspirates of patients younger than 5 years old that were hospitalized during 2013 due ARTI. HBoV DNA was assayed using PCR described by Allander et al. Traditional virnses were studied by immunofluorescence. Personal, clinical and epidemiological data were collected in a standardized form. RESULTS: The HBoV was detected in 7% of the samples and was prevalent in spring and summer and in children younger of 2 years old. Other respiratory viruses were detected in 22% of HBoV positive samples. DISCUSSION: We detected HBoV in these two provinces of Argentina. Further studies should be performed to determine if it's a recent infection or prolonged viral shedding.

The methionine precursor DL-2-hydroxy-(4-methylthio)butanoic acid protects intestinal epithelial barrier function.

DL-2-hydroxy-(4-methylthio)butanoic acid (HMTBA) is a source of dietary methionine (Met) that is widely used in poultry nutrition. We have previously shown that HMTBA is preferentially diverted to the transsulfuration pathway, which gives antioxidant metabolites such as taurine and glutathione. Therefore, here we hypothesize that this Met source can protect epithelial barrier function in an in vitro model of intestinal inflammation of Caco-2 cells. The results show that HMTBA prevents the increase in paracellular permeability induced by H2O2 or tumour necrosis factor-α. This effect can be attributed to the increased production of taurine and reduced glutathione. Similar results were obtained for DL-Met, although the protective role of the amino acid was less pronounced than that of the hydroxy analogue. In conclusion, the diversion to the transsulfuration pathway means that this Met precursor is of greater value than previously thought, due to its capacity to improve intestinal homeostasis and the quality of poultry products destined for human consumption.

Mortality, severe acute respiratory infection, and influenza-like illness associated with influenza A(H1N1)pdm09 in Argentina, 2009.

INTRODUCTION: While there is much information about the burden of influenza A(H1N1)pdm09 in North America, little data exist on its burden in South America. METHODS: During April to December 2009, we actively searched for persons with severe acute respiratory infection and influenza-like illness (ILI) in three sentinel cities. A proportion of case-patients provided swabs for influenza testing. We estimated the number of case-patients that would have tested positive for influenza by multiplying the number of untested case-patients by the proportion who tested positive. We estimated rates by dividing the estimated number of case-patients by the census population after adjusting for the proportion of case-patients with missing illness onset information and ILI case-patients who visited physicians multiple times for one illness event. RESULTS: We estimated that the influenza A(H1N1)pdm09 mortality rate per 100,000 person-years (py) ranged from 1.5 among persons aged 5-44 years to 5.6 among persons aged ≥ 65 years. A(H1N1)pdm09 hospitalization rates per 100,000 py ranged between 26.9 among children aged <5 years to 41.8 among persons aged ≥ 65 years. Influenza A(H1N1)pdm09 ILI rates per 100 py ranged between 1.6 among children aged <5 to 17.1 among persons aged 45-64 years. While 9 (53%) of 17 influenza A(H1N1)pdm09 decedents with available data had obesity and 7 (17%) of 40 had diabetes, less than 4% of surviving influenza A(H1N1)pdm09 case-patients had these pre-existing conditions (p ≤ 0.001). CONCLUSION: Influenza A(H1N1)pdm09 caused a similar burden of disease in Argentina as in other countries. Such disease burden suggests the potential value of timely influenza vaccinations.

ß-Galactomannan and Saccharomyces cerevisiae var. boulardii modulate the immune response against Salmonella enterica serovar Typhimurium in porcine intestinal epithelial and dendritic cells.

Salmonella enterica serovar Typhimurium is a facultative intracellular pathogen that causes inflammation, necrosis, and diarrhea in pigs, as well as being an important source of food-borne diseases in humans. Probiotics and prebiotics are promising alternatives to antibiotics to control and prevent intestinal infections. The present work investigated a recently developed ß-galactomannan (ßGM) prebiotic compared to the proven probiotic Saccharomyces cerevisiae var. boulardii on porcine ileum intestinal epithelial cells (IECs) of the IPI-2I line and monocyte-derived dendritic cells (DCs) cocultured in vitro with Salmonella. We observed that both S. cerevisiae var. boulardii and ßGM inhibited the association of Salmonella with IECs in vitro. Our data indicated that ßGM has a higher ability than S. cerevisiae var. boulardii to inhibit Salmonella-induced proinflammatory mRNA (cytokines tumor necrosis factor alpha [TNF-α], interleukin-1α [IL-1α], IL-6, and granulocyte-macrophage colony-stimulating factor [GM-CSF] and chemokines CCL2, CCL20, and CXCL8) and at protein levels (IL-6 and CXCL8). Additionally, ßGM and S. cerevisiae var. boulardii induced some effects on DCs that were not observed on IECs: ßGM and S. cerevisiae var. boulardii showed slight upregulation of mRNA for TNF-α, GM-CSF, and CCR7 receptor on porcine monocyte-derived dendritic cells (DCs). Indeed, the addition of ßGM or S. cerevisiae var. boulardii on DCs cocultured with Salmonella showed higher gene expression (mRNA) for TNF-α, GM-CSF, and CXCL8 compared to that of the control with Salmonella. In conclusion, the addition of ßGM inhibits Salmonella-induced proinflammatory profiles in IECs but may promote DC activation, although associated molecular mechanisms remain to be elucidated.

Detección de bocavirus humano en la población infantil de Tucumán y Santa Fe, Argentina / Detection of human bocavirus in children from Tucuman and Santa Fe, Argentina

Background: A large proportion of acute respiratory tract infections (ARTI) remain without etiologic diagnosis, reason why new pathogens are investigated continuously. Human bocavirus (HBoV) was discovered in 2005, as a new member of Parvoviridae family and proposed to cause ARTI. Aim: To know the prevalence of HBoV among pediatric populations hospitalized for ARTI in two provinces of Argentina: Santa Fe and Tucuman; and to describe epidemiological and clinical aspects associated to its detection. Materials and Methods: We studied nasopharyn-geal aspirates of patients younger than 5 years old that were hospitalized during 2013 due ARTI. HBoV DNA was assayed using PCR described by Allander et al. Traditional virnses were studied by immunofluorescence. Personal, clinical and epidemiological data were collected in a standardized form. Results: The HBoV was detected in 7% of the samples and was prevalent in spring and summer and in children younger of 2 years old. Other respiratory viruses were detected in 22% of HBoV positive samples. Discussion: We detected HBoV in these two provinces of Argentina. Further studies should be performed to determine if it’s a recent infection or prolonged viral shedding.

Introducción: Un alto porcentaje de las infecciones respiratorias agudas (IRA) permanece sin diagnostico etiológico, por lo cual se investigan nuevos patógenos continuamente. Bocavirus humano (HBoV) fue descubierto en 2005, como un nuevo miembro de la familia Parvoviridae y propuesto como causante de IRA. Objetivos: Investigar la prevalencia de HBoV en niños bajo 5 años de edad, hospitalizados por IRA en dos provincias de Argentina: Santa Fe y Tucumán y describir aspectos epidemiológicos y clínicos asociados a su detección. Materiales y Métodos: Se estudiaron retrospectivamente los aspirados nasofaríngeos (ANF) de pacientes bajo 5 años de edad, con diagnóstico de IRA, hospitalizados durante el año 2013. La presencia de HBoV se detectó mediante la RPC de punto final descripta por Allander y cols. Los virus tradicionales se estudiaron mediante inmunofluorescencia. Datos personales, clínicos y epidemiológicos se recolectaron en una planilla estandarizada. Resultados: HBoV fue detectado en 7% de las muestras con prevalencia en primavera y verano; y principalmente en pacientes bajo 2 años de edad. Se registró co-detecciones en 22% de los casos. Discusión: Hemos detectado HBoV en estas dos provincias de Argentina; estudios posteriores deberán efectuarse para determinar si se trata de una infección reciente o una excreción prolongada del virus.

Optimización de un medio de cultivo para el crecimiento de Gardnerella vaginalis / Optimization of a cultural medium for growing Gardnerella vaginalis

Se presenta una técnica para la optimización del medio de cultivo Caldo Triptona Soya suplementado con suero equino para el crecimiento de Gardnerella vaginalis. Se utilizó un diseño experimental 2² donde se evaluó la influencia de dos componentes del medio y un diseño compuesto central para mejorar los rendimientos celulares. Con la mejor variante de este estudio se realizaron corridas para caracterizar el crecimiento bacteriano empleando diferentes estimaciones. Se obtuvo que la dirección hacia los mayores crecimientos se localizó hacia mayores concentraciones de triptona soya y suero equino. La variación en la concentración de los componentes evaluados no influyó en la expresión de las proteínas antigénicas dado por los perfiles electroforéticos obtenidos.

The optimization of the cultural medium Soy Triptone Broth supplemented with equine serum to grow Gardnerella vaginalis is presented in this paper. An experimental design 2² was used in which the influence of two components of this medium was evaluated; and a central design aimed at improving cell performances. With the best variant of this study, the runs allowed characterize the bacterial growth using different estimations. The greatest growths were observed in higher concentrations of soy triptone and equine serum. The variation of the evaluated component concentrations did not have an impact on the expression of antigenic proteins given by the obtained electrophoretic profiles.

Rubéola: un problema a resolver / Rubella: a problem to be solved

La recopilación de estos datos tuvo como objetivo conocer la incidencia de rubéola en Tucumán (Argentina) durante 1993 a 1997. En el mencionado período se recibieron 1.221 pedidos de investigación de anticuerpos antirubéola que correspondieron a pacientes con sintomatología compatible con infección rubeólica o con contactos intra o extrafamiliar, niños, adolescentes, adultos y embarazadas; niños con sintomatología por posible síndrome de rubéola congénita (SRC) y mujeres para evaluación del estado inmune, procedentes de diferentes localidades de la provincia de Tucumán. Los métodos utilizados para la detección sérica de anticuerpos de rubéola fueron: enzimoenmunoanálisis (ELISA) para IgM específica e Inhibición de la Hemaglutinación (IHA) para anticuerpos totales. Los resultados indicaron mayor número de confirmación de primoinfección rubeólica durante 1993 y 1997 y detección de 20,6 y 19,1 por ciento de mujeres de 22 a 24 años de edad seronegativas durante los años mencionados; además, en 5 de un total de 9 consultas se determinó infección congénita en 1993. A los años 1993 y 1997 se considera períodos epidémicos en esta región, coincidente con lo reportado para otras regiones de las Américas

Variación temporal de electroferotipos y serotipos de Rotavirus humanos en el noroeste argentino / Temporal variation of human rotavirus electropherotypes and serotypes in the northwest of Argentine

La epidemiología de los Rotavirus se investigó en Tucumán entre los años 1986 y 1991. Durante este período se estudiaron 1462 muestras fecales de niños con gastroenteritis, de edades comprendidas entre los 0 y 5 años. La detección viral se realizó por ELISA específico para Rotavirus del grupo A y electroforesis del ARN viral en gel de poliacrilamida (PAGE). Resultaron positivas 353 muestras (24,1 por ciento). El análisis de los electroferotipos (EFT) permitió establecer la prevalencia de cepas circulantes a patrón largo y corto, la permanencia de lagunas en años sucesivos, desaparición y presencia de nuevos EFT. Se detectaron brotes periódicos de EFT cortos en los años 1987 y 1990. Exceptuando un EFT, todos fueron característicos del grupo A de Rotavirus. Del total de muestras positivas, 127 fueron serotipificadas mediante técnica de ELISA, con anticuerpos monoclonales, dirigidos contra VP7, polipéptido principal de la cápside externa viral, con especificidad para los serotipos 1, 2, 3 y 4. Los resultados mostraron una predominancia variable en diferentes años. Los datos presentados sugieren: 1)cambios permanentes de los subpatrones electroforéticos; 2)variación cíclica de los serotipos en los 6 años estudiados

Determinación de niveles de anticuerpos para rubéola en Tucumán (Argentina) 1982-1992 / Levels of rubella antibodies in Tucuman (Argentine) 1982-1992

El presente estudio permitió conocer las fluctuaciones cronológicas de la rubéola, y su relación con los ciclos epidémicos e interepidémicos en la provincia de Tucumán. La valoración de anticuerpos fue realizada por inhibición de la Hemoaglutinación (IHA). Se atendieron durante los últimos 10 años 1570 consultas. Se realizó confirmación diagnóstica en pares de sueros de 550 embarazadas y 750 contactos. Se incluyen ademós los resultados obtenidos de dos encuestas serológicas en estudiantes secundarias y universitarias (270 muestras), detectándose en esta población 16 por ciento de susceptibles. El análisis de los datos revela que esta enfermedad adopta la forma endemoepidémica. Está presente durante durante todo el año y todos los años con brotes estacionales en primavera y picos periódicos de mayor magnitud cada cuatro-seis años aproximadamente. Se inician en julio-agosto, alcanzan su máximo entre octubre-diciembre y declinan en febrero-marzo. Por confirmación serológica y datos suministrados por el Sistema Provincial de Salud, se detectaron tres ondas epidémicas en nuestra provincia en 1983, 1988 y 1992, siendo la de mayor intensidad la de 1992