Data_Sheet_1_Anopheline mosquito saliva contains bacteria that are transferred to a mammalian host through blood feeding.zip

IntroductionMalaria transmission occurs when Plasmodium sporozoites are transferred from the salivary glands of anopheline mosquitoes to a human host through the injection of saliva. The need for better understanding, as well as novel modes of inhibiting, this key event in transmission has driven intense study of the protein and miRNA content of saliva. Until now the possibility that mosquito saliva may also contain bacteria has remained an open question despite the well documented presence of a rich microbiome in salivary glands.MethodsUsing both 16S rRNA sequencing and MALDI-TOF approaches, we characterized the composition of the saliva microbiome of An. gambiae and An. stephensi mosquitoes which respectively represent two of the most important vectors for the major malaria-causing parasites P. falciparum and P. vivax.ResultsTo eliminate the possible detection of non-mosquito-derived bacteria, we used a transgenic, fluorescent strain of one of the identified bacteria, Serratiamarcescens, to infect mosquitoes and detect its presence in mosquito salivary glands as well as its transfer to, and colonization of, mammalian host tissues following a mosquito bite. We also showed that Plasmodium infection modified the mosquito microbiota, increasing the presence of Serratia while diminishing the presence of Elizabethkingia and that both P. berghei and Serratia were transferred to, and colonized mammalian tissues.DiscussionThese data thus document the presence of bacteria in mosquito saliva, their transfer to, and growth in a mammalian host as well as possible interactions with Plasmodium transmission. Together they raise the possible role of mosquitoes as vectors of bacterial infection and the utility of commensal mosquito bacteria for the development of transmission-blocking strategies within a mammalian host.</p

Body weight, number of BALs, and baseline as well as post-BALs (respiratory failure) values of PaO₂ and C_dyn in adult rabbits included in the study.

<p>Body weight, number of BALs, and baseline as well as post-BALs (respiratory failure) values of PaO₂ and C_dyn in adult rabbits included in the study.</p

Dynamic compliance (C_dyn) of surfactant-depleted rabbits managed with non-invasive ventilation.

<p>To the left of the dashed line, the baseline and post-surfactant depletion C_dyn values of all the animals featured in the study are given. To the right of the dashed line, the C_dyn values of the different groups after 180 minutes of management with NIV are shown. Surfactant-treated groups are represented by the box-plots with a grey filling, whereas the groups merely treated with NIV are represented by the white box-plots. The small squares within each box-plot indicate the mean of the group. The whiskers indicate the maximum and minimum values observed for each group. ^# <i>P</i> < 0.01 vs. SNIPPV+SF group. NCPAP: nasal continuous positive airway pressure, SF: surfactant, NIPPV: nasal (non-synchronized) intermittent positive pressure ventilation, and SNIPPV: synchronized NIPPV.</p

Histological scores of surfactant-depleted adult rabbits.

<p>Histological scores of surfactant-depleted adult rabbits.</p

Mean PaO₂ values over time of surfactant-depleted rabbits managed with non-invasive ventilation.

<p>Surfactant-depleted adult rabbits were treated with nasal continuous positive pressure ventilation (NCPAP, white diamonds), with NCPAP + intratracheal surfactant (NCPAP+SF, black diamonds), with nasal non-synchronized intermittent positive ventilation (NIPPV, white squares), with NIPPV + intratracheal surfactant (NIPPV+SF, black squares), with Synchronized Intermittent Positive Pressure Ventilation (SNIPPV, white circles), or with SNIPPV + intratracheal surfactant (SNIPPV+SF, black circles). Surfactant-treated animals (black symbols) received a bolus of surfactant before extubation, immediately after the 0 time-point. Values are shown as the mean ± SEM. * <i>P</i> vs. NIPPV+SF group < 0.01; ^# <i>P</i> vs. SNIPPV group < 0.01; ^§ <i>P</i> vs. NCPAP group < 0.01; ^& <i>P</i> vs. NIPPV group < 0.01.</p

The oxygenation index (OI) and the ventilation efficacy index (VEI) of surfactant-depleted rabbits managed with non-invasive ventilation.

<p>To the left of the dashed line, the baseline and post-surfactant depletion OI (A) and VEI (B) values of all the animals featured in the study are given. To the right of the dashed line, the OI and VEI values of the different groups after 180 minutes of management with NIV are shown. Surfactant-treated groups are represented by the box-plots with a grey filling, whereas the groups treated with NIV only are represented by the white box-plots. The small squares within each box-plot indicate the mean of the group. The whiskers indicate the maximum and minimum values observed for each group. * <i>P</i> < 0.01 vs. any group not treated with surfactant; ^# <i>P</i> < 0.01 vs. SNIPPV+SF group. NCPAP: nasal continuous positive airway pressure, SF: surfactant, NIPPV: nasal (non-synchronized) intermittent positive pressure ventilation, and SNIPPV: synchronized NIPPV.</p

Histological microphotographs of surfactant-depleted rabbits managed with non-invasive ventilation.

<p>Histological overview of lung parenchyma presenting representative inflammatory infiltrate, hemorrhage, edema and atelectasis for all groups. SF: surfactant; NCPAP: nasal continuous positive airway pressure (A,B); NIPPV: nasal intermittent positive pressure ventilation (C,D); SNIPPV: synchronized NIPPV (E,F). Haematoxylin & Eosin staining, scale bar 250 μm.</p