Fungal microbiota in newborn infants with and without respiratory distress syndrome.

BACKGROUND: Pneumocytis jirovecii infection in preterm newborns has recently been associated with neonatal respiratory distress syndrome and bronchopulmonary dysplasia. Changes in the bacterial microbiota of the airways have also been described in infants with bronchopulmonary dysplasia. However, until now there has been no information on the airway mycobiota in newborns. The purpose of this study was to describe the airway mycobiota in term and preterm newborns and its possible association with respiratory distress syndrome. METHODS: Twenty-six matched preterm newborns with and without respiratory distress syndrome were studied, as well as 13 term babies. The identification of the fungal microbiota was carried out using molecular procedures in aspirated nasal samples at birth. RESULTS: The ascomycota phylum was identified in 89.7% of newborns, while the basidiomycota phylum was found in 33.3%. Cladosporium was the predominant genus in both term and preterm infants 38.4% vs. 73% without statistical differences. Candida sake and Pneumocystis jirovecii were only found in preterm infants, suggesting a potential relationship with the risk of prematurity. CONCLUSIONS: This is the first report to describe the fungal microbiota of the airways in term and preterm infants with and without respiratory distress syndrome. Although no differences have been observed, the number of cases analyzed could be small to obtain conclusive results, and more studies are needed to understand the role of the fungal microbiota of the airways in neonatal respiratory pathology.

Biophysical evaluation of antiparallel triplexes for biosensing and biomedical applications.

Polypyrimidine sequences can be targeted by antiparallel clamps forming triplex structures either for biosensing or therapeutic purposes. Despite its successful implementation, their biophysical properties remain to be elusive. In this work, PAGE, circular dichroism and multivariate analysis were used to evaluate the properties of PPRHs directed to SARS-CoV-2 genome. Several PPRHs designed to target various polypyrimidine sites within the viral genome were synthesized. These PPRHs displayed varying binding affinities, influenced by factors such as the length of the PPRH and its GC content. The number and position of pyrimidine interruptions relative to the 4 T loop of the PPRH was found a critical factor, affecting the binding affinity with the corresponding target. Moreover, these factors also showed to affect in the intramolecular and intermolecular equilibria of PPRHs alone and when hybridized to their corresponding targets, highlighting the polymorphic nature of these systems. Finally, the functionality of the PPRHs was evaluated in a thermal lateral flow sensing device showing a good correspondence between their biophysical properties and detection limits. These comprehensive studies contribute to the understanding of the critical factors involved in the design of PPRHs for effective targeting of biologically relevant genomes through the formation of triplex structures under neutral conditions.

Colonización por Pneumocystis jirovecii en mujeres gestantes y recién nacidos en Lima, Perú / neumocystis jirovecii colonisation in pregnant women and newborns in Lima, Peru

ANTECEDENTES: La primoinfección por Pneumocystis jirovecii ocurre de forma asintomática antes de los 6 meses de edad, lo que sugiere que la infección se adquiere muy precozmente en la vida. Se ha descrito también la presencia de neumonía por Pneumocystis en recién nacidos, lo que indica la necesidad de estudiar la colonización en el binomio madre-hijo. OBJETIVOS: Evaluar la prevalencia de colonización de Pneumocystis en gestantes y explorar la potencial transmisión transplacentaria. MÉTODOS: Estudio transversal que incluyó a mujeres gestantes mayores de 18 años con 37 o más semanas de gestación y negativas para el VIH que acudieron al Hospital Cayetano Heredia en los años 2016-2017. Se obtuvo información clínica y demográfica de la gestante y del recién nacido. Se tomaron muestras de lavado orofaríngeo/hisopado nasal de la gestante, de placenta y de aspirado nasofaríngeo/hisopado nasal del recién nacido. Todas las muestras respiratorias fueron analizadas mediante PCR anidada. En el caso de las muestras de placenta solo fueron analizadas aquellas procedentes de mujeres con resultados positivos de PCR para Pneumocystis en las muestras respiratorias. RESULTADOS: De las 92 gestantes incluidas en el estudio cinco presentaban colonización por Pneumocystis (5,43%). Se evaluaron las muestras de 87 recién nacidos y las placentas de las cinco madres con PCR positiva, no encontrándose ADN de Pneumocystis en ninguna de ellas. CONCLUSIONES: Aunque el 5,43% de las mujeres gestantes estuvieran colonizadas por Pneumocystis no pudo determinarse el rol de esta colonización en la transmisión a sus recién nacidos, ya que en ninguno de ellos se demostró la presencia de Pneumocystis

BACKGROUND: Pneumocystisjirovecii primary infection occurs asymptomatically before 6 months of age, suggesting that the infection is acquired very early in life. Furthermore, Pneumocystis pneumonia has been described in newborns, which emphasizes the importance of studying Pneumocystis colonization in mother-infant pairs. AIMS: To evaluate the prevalence of Pneumocystis colonization among pregnant women and to determine the potential transplacental transmission. METHODS: A cross-sectional study was carried out on HIV-negative women over 18 years-old, and 37 or more weeks of pregnancy attending Hospital Cayetano Heredia Maternity unit during 2016-2017. Clinical and demographical information was collected on them and their newborns. Oropharyngeal washes, nasal swabs, and placenta samples were collected from women, as well as a nasopharyngeal aspirate and nasal swab from newborns. All respiratory samples were analysed by nested-PCR for the detection of Pneumocystis. Placenta samples from women with a positive PCR result in their respiratory samples were also analysed by nested-PCR. RESULTS: Of the 92 pregnant women included, five of them (5.43%) were colonized by Pneumocystis. Pneumocystis DNA was not found in any of the 87 available newborn samples or in the placentas of the five women who had a positive result by PCR in their upper respiratory samples. CONCLUSIONS: It was found that 5.43% of the pregnant women were colonized by Pneumocystis, there was no evidence of any role of this colonization in the transmission to their newborns, since none of them tested positive for Pneumocystis