Nasopharyngeal microbiota profiling of pregnant women with SARS-CoV-2 infection.

Abstract

We aimed to analyze the nasopharyngeal microbiota profles in pregnant women with and without SARS-CoV-2 infection, considered a vulnerable population during COVID-19 pandemic. Pregnant women were enrolled from a multicenter prospective population-based cohort during the frst SARS-CoV-2 wave in Spain (March-June 2020 in Barcelona, Spain) in which the status of SARSCoV-2 infection was determined by nasopharyngeal RT–PCR and antibodies in peripheral blood. Women were randomly selected for this cross-sectional study on microbiota. DNA was extracted from nasopharyngeal swab samples, and the V3-V4 region of the 16S rRNA of bacteria was amplifed using region-specifc primers. The diferential abundance of taxa was tested, and alpha/beta diversity was evaluated. Among 76 women, 38 were classifed as positive and 38 as negative for SARS-CoV-2 infection. All positive women were diagnosed by SARS-CoV-2 IgG and IgM/IgA antibodies, and 14 (37%) also had a positive RT–PCR. The overall composition of the nasopharyngeal microbiota difer in pregnant women with SARS-CoV-2 infection (positive SARS-CoV-2 antibodies), compared to those without the infection (negative SARS-CoV-2 antibodies) (p = 0.001), with a higher relative abundance of the Tenericutes and Bacteroidetes phyla and a higher abundance of the Prevotellaceae family. Infected women presented a diferent pattern of microbiota profling due to beta diversity and higher richness (observed ASV< 0.001) and evenness (Shannon index < 0.001) at alpha diversity. These changes were also present in women after acute infection, as revealed by negative RT–PCR but positive SARS-CoV-2 antibodies, suggesting a potential association between SARS-CoV-2 infection and long-lasting shift in the nasopharyngeal microbiota. No signifcant diferences were reported inmild vs. severe cases. This is the frst study on nasopharyngeal microbiota during pregnancy. Pregnant women with SARS-CoV-2 infection had a diferent nasopharyngeal microbiota profle compared to negative cases.