Neisseria meningitidis, the causative agent of meningitis and septicemia, attaches to and invades various cell types. Both steps induce and/or require tyrosine phosphorylation of host cell proteins. Here, we used a phospho array platform to identify active receptor tyrosine kinases (RTKs) and key signaling nodes in N. meningitidis-infected brain endothelial cells to decipher RTKdependent signaling pathways necessary for bacterial uptake. We detected several activated RTKs, including the ErbB family receptors epidermal growth factor receptor (EGFR), ErbB2, and ErbB4. We found that pharmacological inhibition and genetic ablation of ErbB receptor tyrosine phosphorylation and expression resulted in decreased bacterial uptake and heterologous expression of EGFR, ErbB2, or ErbB4 in Chinese ovary hamster (CHO-K1) cells, which do not express of EGFR and ErbB4; the decrease caused a significant increase in meningococcal invasion. Activation of EGFR and ErbB4 was mediated by transactivation via the common ligand HB-EGF (heparin-binding EGF-like ligand), which was significantly elevated in infected cell culture supernatants. We furthermore determined that N. meningitidis induced phosphorylation of EGFR at Tyr845 independent of ligand binding, which required c-Src activation and was involved in mediating uptake of N. meningitidis into eukaryotic cells. Increased uptake was repressed by expression of EGFR Y845F, which harbored a point mutation in the kinase domain. In addition, activation of ErbB4 at its autophosphorylation site, Tyr1284, and phosphorylation of ErbB2 Thr686 were observed. Altogether, our results provide evidence that EGFR, ErbB2, and ErbB4 are activated in response to N. meningitidis infection and shed new light on the role of ErbB signaling in meningococcal infection biology. N eisseria meningitidis is a common colonizing bacterium of the human nasopharynx and can be found in 8 to 20% of healthy individuals (1). In rare cases, N. meningitidis overcomes the epithelial barrier and enters the bloodstream, followed by a severe septicemia or by an acute purulent meningitis (2). To cross cellular barriers, N. meningitidis has evolved with the ability to attach to and invade into a variety of cell types. N. meningitidis interacts with host cells by using several microbial structures, including type IV pili (TfP), the outer membrane adhesion proteins Opa and Opc, and the newly identified minor adhesion or adhesion-like proteins that mediate binding to different receptors (3-8). Subsequently, binding to receptors enables the pathogen to exploit the endocytotic capacity of the receptor to promote its internalization. In addition to the engagement of a specific receptor, microorganisms might indirectly activate signal transduction pathways and co-opt receptor signal transduction mechanisms to induce host cell signaling pathways that in turn lead to cytoskeleton rearrangements and bacterial uptake.It has been established that N. meningitidis can signal through receptor tyrosine kinases (RTKs) and non-RTKs to promote th...

IMPORTANCEClosure of day care centers has been implemented globally to contain the COVID-19 pandemic but has negative effects on children's health and psychosocial well-being. OBJECTIVE To investigate the feasibility of surveillance among children and childcare workers and to model the efficacy of surveillance on viral spread prevention. DESIGN, SETTING, AND PARTICIPANTS This nonrandomized controlled trial was conducted at 9 day care centers in Wuerzburg, Germany, from October 2020 to March 2021. Participants included children attending day care, childcare workers, and household members. Participating day care centers were assigned to different surveillance modules in a nonrandomized feasibility study. A mathematical model for SARS-CoV-2 spread in day care centers was developed to identify optimal surveillance. INTERVENTIONS Modules 1, 2, and 3 involved continuous surveillance of asymptomatic children and childcare workers by SARS-CoV-2 polymerase chain reaction testing of either midturbinate nasal swabs twice weekly (module 1) or once weekly (module 2) or self-sampled saliva samples twice weekly (module 3). Module 4 involved symptom-based, on-demand testing of children, childcare workers, and their household members by oropharyngeal swabs. All participants underwent SARS-CoV-2 antibody status testing before and after the sampling period. Questionnaires on attitudes and perception of the pandemic were administered in weeks 1, 6, and 12. Mathematical modeling was used to estimate SARS-CoV-2 spread in day care centers. MAIN OUTCOMES AND MEASURES The primary outcomes were acceptance of the respective surveillance protocols (feasibility study) and the estimated number of secondary infections (mathematical modeling). RESULTS Of 954 eligible individuals (772 children and 182 childcare workers), 592 (62%), including 442 children (median [IQR] age, 3 [2-4] years; 214 [48.6%] female) and 150 childcare workers (median [IQR] age, 29 [25-44] years; 129 [90.8%] female) participated in the surveillance. In total, 4755 tests for SARS-CoV-2 detected 2 infections (1 childcare worker and 1 adult household member). Acceptance for continuous surveillance was highest for biweekly saliva testing (150 of 221 eligible individuals [67.9%; 95% CI, 61.5%-73.7%]) compared with biweekly (51 of 117 individuals [43.6%; 95% CI, 35.0%-52.6%]) and weekly (44 of 128 individuals [34.4%; 95% CI, 26.7%-43.0%]) midturbinate swabbing (P < .001). Dropout rates were higher for midturbinate swabbing (biweekly, 11 of 62 participants [18%]; once weekly, 11 of 55 participants [20%]) than for saliva testing (6 of 156 (continued) Key Points Question Is continuous SARS-CoV-2 testing accepted by children, parents, and childcare workers and can it prevent viral spreading in day care centers? Findings In this nonrandomized controlled trial, surveillance testing for SARS-CoV-2 among 954 eligible individuals was well accepted by children, parents, and childcare workers if saliva sampling at home was used. Mathematical modeling based on study and literature data iden...