Even laypeople use legalese.

Whereas principles of communicative efficiency and legal doctrine dictate that laws be comprehensible to the common world, empirical evidence suggests legal documents are largely incomprehensible to lawyers and laypeople alike. Here, a corpus analysis (n = 59) million words) first replicated and extended prior work revealing laws to contain strikingly higher rates of complex syntactic structures relative to six baseline genres of English. Next, two preregistered text generation experiments (n = 286) tested two leading hypotheses regarding how these complex structures enter into legal documents in the first place. In line with the magic spell hypothesis, we found people tasked with writing official laws wrote in a more convoluted manner than when tasked with writing unofficial legal texts of equivalent conceptual complexity. Contrary to the copy-and-edit hypothesis, we did not find evidence that people editing a legal document wrote in a more convoluted manner than when writing the same document from scratch. From a cognitive perspective, these results suggest law to be a rare exception to the general tendency in human language toward communicative efficiency. In particular, these findings indicate law's complexity to be derived from its performativity, whereby low-frequency structures may be inserted to signal law's authoritative, world-state-altering nature, at the cost of increased processing demands on readers. From a law and policy perspective, these results suggest that the tension between the ubiquity and impenetrability of the law is not an inherent one, and that laws can be simplified without a loss or distortion of communicative content.

The multifunction Coxiella effector Vice stimulates macropinocytosis and interferes with the ESCRT machinery.

Intracellular bacterial pathogens divert multiple cellular pathways to establish their niche and persist inside their host. Coxiella burnetii, the causative agent of Q fever, secretes bacterial effector proteins via its Type 4 secretion system to generate a Coxiella-containing vacuole (CCV). Manipulation of lipid and protein trafficking by these effectors is essential for bacterial replication and virulence. Here, we have characterized the lipid composition of CCVs and found that the effector Vice interacts with phosphoinositides and membranes enriched in phosphatidylserine and lysobisphosphatidic acid. Remarkably, eukaryotic cells ectopically expressing Vice present compartments that resemble early CCVs in both morphology and composition. We found that the biogenesis of these compartments relies on the double function of Vice. The effector protein initially localizes at the plasma membrane of eukaryotic cells where it triggers the internalization of large vacuoles by macropinocytosis. Then, Vice stabilizes these compartments by perturbing the ESCRT machinery. Collectively, our results reveal that Vice is an essential C. burnetii effector protein capable of hijacking two major cellular pathways to shape the bacterial replicative niche.

Even lawyers do not like legalese.

Across modern civilization, societal norms and rules are established and communicated largely in the form of written laws. Despite their prevalence and importance, legal documents have long been widely acknowledged to be difficult to understand for those who are required to comply with them (i.e., everyone). Why? Across two preregistered experiments, we evaluated five hypotheses for why lawyers write in a complex manner. Experiment 1 revealed that lawyers, like laypeople, were less able to recall and comprehend legal content drafted in a complex "legalese" register than content of equivalent meaning drafted in a simplified register. Experiment 2 revealed that lawyers rated simplified contracts as equally enforceable as legalese contracts, and rated simplified contracts as preferable to legalese contracts on several dimensions-including overall quality, appropriateness of style, and likelihood of being signed by a client. These results suggest that lawyers who write in a convoluted manner do so as a matter of convenience and tradition as opposed to an outright preference and that simplifying legal documents would be both tractable and beneficial for lawyers and nonlawyers alike.

A cost comparison of liver acquisition fees for donation after circulatory death versus donation after brain death donors.

Donation after circulatory death (DCD) donors now represent over 30% of the deceased donor pool in the United States. Compared to donation after brain death, DCD is less likely to result in transplantation. For each potential donor whose organs cannot be utilized for transplantation (ie, dry run), fees are associated with the attempted donation, which add to the overall costs of organ acquisition. To better characterize the true costs of DCD liver acquisition, we performed a cost comparison of the fees associated with organ acquisition for DCD versus donation after brain death at a single transplant institute that comprises 2 liver transplant centers. Cost, recipient, and transportation data for all cases, including fees associated with liver acquisition from July 1, 2019, to October 31, 2021, were collected. We found that the total cost of DCD liver acquisition per liver transplant was $15,029 more than that for donation after brain death donation, with 18% of the costs of the DCD transplant attributed to dry runs. Overall, the costs associated with DCD transplantation accounted for 34.5% of the total organ acquisition costs; however, DCD transplantation accounted for 30.3% of the transplantation volume. Because the expansion of DCD is essential to increasing the availability of liver grafts for transplantation, strategies need to be implemented to decrease the costs associated with dry runs, including using local recovery, transferring donors to hospitals close to transplant centers, and performing more prerecovery organ analysis. Moreover, these strategies are needed to ensure that financial disincentives to DCD procurement and utilization do not reverse the gains made by expanding the organ donor pool using machine perfusion technologies.

Stepwise development and expansion of an abdominal normothermic regional perfusion program for donation after circulatory determination of death organ procurement.

INTRODUCTION: Normothermic regional perfusion (NRP) represents an innovative technology that improves the outcomes for liver and kidney recipients of donation after circulatory determination of death (DCD) organs but protocols for abdominal-only NRP (A-NRP) DCD are lacking in the US. METHODS: We describe the implementation and expansion strategies of a transplant-center-based A-NRP DCD program that has grown in volume, geographical reach, and donor acceptance parameters, presented as four eras. RESULTS: In the implementation era, two donors were attempted, and one liver graft was transplanted. In the local expansion era, 33% of attempted donors resulted in transplantation and 42% of liver grafts from donors who died within the functional warm ischemic time (fWIT) limit were transplanted. In the Regional Expansion era, 25% of attempted donors resulted in transplantation and 50% of liver grafts from donors who died within the fWIT limit were transplanted. In the Donor Acceptance Expansion era, 46% of attempted donors resulted in transplantation and 72% of liver grafts from donors who died within the fWIT limit were transplanted. Eight discarded grafts demonstrated a potential opportunity for utilization. CONCLUSION: The stepwise approach to building an A-NRP program described here can serve as a model for other transplant centers.

Uterus Transplant in Women With Absolute Uterine-Factor Infertility.

Importance: Uterus transplant in women with absolute uterine-factor infertility offers the possibility of carrying their own pregnancy. Objective: To determine whether uterus transplant is feasible and safe and results in births of healthy infants. Design, Setting, and Participants: A case series including 20 participants with uterine-factor infertility and at least 1 functioning ovary who underwent uterus transplant in a large US tertiary care center between September 14, 2016, and August 23, 2019. Intervention: The uterus transplant (from 18 living donors and 2 deceased donors) was surgically placed in an orthotopic position with vascular anastomoses to the external iliac vessels. Participants received immunosuppression until the transplanted uterus was removed following 1 or 2 live births or after graft failure. Main Outcomes and Measures: Uterus graft survival and subsequent live births. Results: Of 20 participants (median age, 30 years [range, 20-36]; 2 Asian, 1 Black, and 16 White), 14 (70%) had a successful uterus allograft; all 14 recipients gave birth to at least 1 live-born infant. Eleven of 20 recipients had at least 1 complication. Maternal and/or obstetrical complications occurred in 50% of the successful pregnancies, with the most common being gestational hypertension (2 [14%]), cervical insufficiency (2 [14%]), and preterm labor (2 [14%]). Among the 16 live-born infants, there were no congenital malformations. Four of 18 living donors had grade 3 complications. Conclusions and Relevance: Uterus transplant was technically feasible and was associated with a high live birth rate following successful graft survival. Adverse events were common, with medical and surgical risks affecting recipients as well as donors. Congenital abnormalities and developmental delays have not occurred to date in the live-born children. Trial Registration: ClinicalTrials.gov Identifier: NCT02656550.

Normothermic regional perfusion procurement for abdominal organ donors: techniques and troubleshooting.

PURPOSE OF REVIEW: Normothermic regional perfusion (NRP) is a novel procurement technique for donation after circulatory death (DCD) in the United States. It was pioneered by cardiothoracic surgery programs and is now being applied to abdominal-only organ donors by abdominal transplant programs. Multiple technical approaches can be used for abdominal-only NRP DCD donors and this review describes these techniques. RECENT FINDINGS: NRP has been associated with higher utilization of organs, particularly liver and heart grafts, from DCD donors and with better recipient outcomes. There are lower rates of delayed graft function in kidney transplant recipients and lower rates of ischemic cholangiopathy in liver transplant recipients. These benefits are driving increased interest from abdominal transplant programs in using NRP for DCD procurements. SUMMARY: This paper describes the technical aspects of NRP DCD that allow for maximization of its use based on different donor and policy characteristics.

Modulation of innate immune signaling by a Coxiella burnetii eukaryotic-like effector protein.

The Q fever agent Coxiella burnetii uses a defect in organelle trafficking/intracellular multiplication (Dot/Icm) type 4b secretion system (T4SS) to silence the host innate immune response during infection. By investigating C. burnetii effector proteins containing eukaryotic-like domains, here we identify NopA (nucleolar protein A), which displays four regulator of chromosome condensation (RCC) repeats, homologous to those found in the eukaryotic Ras-related nuclear protein (Ran) guanine nucleotide exchange factor (GEF) RCC1. Accordingly, NopA is found associated with the chromatin nuclear fraction of cells and uses the RCC-like domain to interact with Ran. Interestingly, NopA triggers an accumulation of Ran-GTP, which accumulates at nucleoli of transfected or infected cells, thus perturbing the nuclear import of transcription factors of the innate immune signaling pathway. Accordingly, qRT-PCR analysis on a panel of cytokines shows that cells exposed to the C. burnetii nopA::Tn or a Dot/Icm-defective dotA::Tn mutant strain present a functional innate immune response, as opposed to cells exposed to wild-type C. burnetii or the corresponding nopA complemented strain. Thus, NopA is an important regulator of the innate immune response allowing Coxiella to behave as a stealth pathogen.

Part of the solution yet part of the problem: factors of schizophrenia stigma in mental health professionals.

BACKGROUND: Stigma is highly prejudicial to persons with schizophrenia, their families, the society and the health care system. Mental health professionals (MHP) are considered to be one of the main sources of schizophrenia stigma. OBJECTIVES: The aim of the study was to identify individual and contextual factors associated with stigma in MHP in its three dimensions (stereotypes, prejudices, discrimination, Fiske, 1998). METHODS: An online survey was conducted with specific measures of MHP stigma (stereotypes, prejudices and discrimination). Four categories of potential associated factors were also measured: sociodemographic characteristics, contextual characteristics (e.g., Work setting), individual characteristics (e.g., Profession, Recovery-oriented practices) and theoretical beliefs (e.g., Biological beliefs, Perceived similarities, Continuum versus Categorical beliefs). RESULTS: Responses of 357 MHP were analysed. Factors that were the most strongly associated with MHP stigma were Perceived similarities, Categorical beliefs, Biological beliefs, Recovery-oriented practice and Work setting (independent practice). Conversely, Gender, Specific trainings in stigma or recovery and Cognitive aetiology beliefs showed no association with any of MHP stigma dimension. Remaining factors show associations with a weak effect size. CONCLUSIONS: The survey results suggest that MHP stigma is more influenced by individual factors such as theoretical beliefs and recovery-oriented practices than contextual factors. These original results provide perspectives for reducing stigma in mental health practices.Key pointsMental health professionals (MHP) considering they share similarities with persons with schizophrenia or believing that schizophrenia is not a discrete social category but rather the extreme on a continuum between 'normal' and 'pathologic' reported less stigmatisation.MHP holding higher professional utility beliefs and using recovery-oriented practice reported fewer stereotypes, prejudice and discrimination.Other factors such as age, academic level, contact frequency, familiarity and multidisciplinary practice show associations with a weak effect size.

Single-center analysis of organ offers and workload for liver and kidney allocation.

The volume of abdominal organ offers received by the Baylor Simmons Transplant Institute has increased over time, resulting in a higher workload for our donor call team. To quantify the increase in organ offers, determine the characteristics of these offers, and estimate the impact on our transplant center workload, we collected center-specific organ offer data from May 2019 to July 2021 using the UNOS Center Acceptance and Refusal Evaluation Report and performed a time study that collected the number of communications and time spent on communications for organ offers made during a typical week. The total offers per month increased by 140% (270/month to 648/month), while the number of transplanted organs remained stable. In addition, the percentage of offers for organs that were never transplanted increased from 54% to 75%. In a representative week-long time study, surgeons made 505, center coordinators 590, and answering service coordinators 318 distinct communications, averaging 3, 4, and 2 communications/hour. Between November 2019 and July 2021, offer-related workload increased by an estimated 97%. These results demonstrate a sizeable inefficiency in abdominal organ allocation associated with a nonrecoverable cost to our transplant center.

Early outcomes of kidney transplant recipients from donors with severe SARS-CoV-2 pneumonia: A report of 5 cases.

BACKGROUND: Transplanting kidneys from donors with a recent history of severe SARS-CoV-2 pneumonia is uncommon due to concerns about the risk of viral transmission and the quality of kidneys from these donors. To date, there are no conclusive data on viral transmission from extrapulmonary solid organ transplants. Given the prevalence of SARS-CoV-2 infections in potential donors, shortage of kidneys available for transplantation, and low risk of viral transmission, we developed a clinical protocol for accepting kidneys from donors with recent severe SARS-CoV-2 pneumonia who demonstrate preserved kidney function. MATERIALS AND METHODS: We collected data on early outcomes of 5 kidney transplant recipients from 4 deceased donors hospitalized for severe SARS-CoV-2 infection. RESULTS: Donor creatinine ranged from 0.51 to 0.60 mg/dL and kidney donor profile index (KDPI) from 14 to 52%. Three of the five kidneys were from donation after circulatory death. All recipients were fully vaccinated, and 4/5 received post-exposure prophylactic monoclonal antibody treatment. While 3 recipients had delayed graft function, all had excellent graft function at 3 or 4 weeks post-operatively. None of the recipients displayed signs or symptoms of SARS-CoV-2 infection post-transplant. CONCLUSION: Our findings suggest that kidney grafts from donors with a recent history of severe SARS-CoV-2 infection but with preserved kidney function can be safely used and have good early outcomes.

The secreted protein kinase CstK from Coxiella burnetii influences vacuole development and interacts with the GTPase-activating host protein TBC1D5.

The intracellular bacterial pathogen Coxiella burnetii is the etiological agent of the emerging zoonosis Q fever. Crucial to its pathogenesis is type 4b secretion system-mediated secretion of bacterial effectors into host cells that subvert host cell membrane trafficking, leading to the biogenesis of a parasitophorous vacuole for intracellular replication. The characterization of prokaryotic serine/threonine protein kinases in bacterial pathogens is emerging as an important strategy to better understand host-pathogen interactions. In this study, we investigated CstK (for Coxiella Ser/Thr kinase), a protein kinase identified in C. burnetii by in silico analysis. We demonstrate that this putative protein kinase undergoes autophosphorylation on Thr and Tyr residues and phosphorylates a classical eukaryotic protein kinase substrate in vitro This dual Thr-Tyr kinase activity is also observed for a eukaryotic dual-specificity Tyr phosphorylation-regulated kinase class. We found that CstK is translocated during infections and localizes to Coxiella-containing vacuoles (CCVs). Moreover, a CstK-overexpressing C. burnetii strain displayed a severe CCV development phenotype, suggesting that CstK fine-tunes CCV biogenesis during the infection. Protein-protein interaction experiments identified the Rab7 GTPase-activating protein TBC1D5 as a candidate CstK-specific target, suggesting a role for this host GTPase-activating protein in Coxiella infections. Indeed, CstK co-localized with TBC1D5 in noninfected cells, and TBC1D5 was recruited to CCVs in infected cells. Accordingly, TBC1D5 depletion from infected cells significantly affected CCV development. Our results indicate that CstK functions as a bacterial effector protein that interacts with the host protein TBC1D5 during vacuole biogenesis and intracellular replication.

Single center results of simultaneous pancreas-kidney transplantation in patients with type 2 diabetes.

Studies have found similar outcomes of Simultaneous Pancreas-Kidney transplantation (SPKT) in patients with Type 2 (T2D) and Type 1 diabetes (T1D). However, there are scarce data evaluating the association of recipient factors such as age, BMI, or pretransplant insulin requirements with outcomes, thus the criteria for the optimal recipient selection remains unclear. In this study, 284 T1D and 39 T2D patients, who underwent SPKT between 2006 and 2017 with 1 year of follow-up at minimum, were assessed for potential relationship of pretransplant BMI and insulin requirements with posttransplant diabetes and pancreatic graft failure. Kaplan-Meier analysis showed similar rates of freedom from posttransplant diabetes (94.7% T2D vs. 92.3% T1D at 1 yr, and 88.1% T2D vs. 81.1% T1D at 5 yrs) and graft survival (89.7% T2D vs. 90.4% T1D at 1 yr, and 89.7% T2D vs. 81.2% T1D at 5 yrs). There was no significant association between BMI or pretransplant insulin requirements with posttransplant diabetes occurrence in either T1D (p = .10, .43, respectively) or T2D (p = .12, .63) patients in the cohort; or with graft failure (T1D: p = .40, .09; T2D: p = .71, .28). These observations suggest a less restricted approach to selective use of SPKT in patients with T2D.

Selective screening imaging of the aortoiliac arterial system in kidney transplant candidates with non-contrast pelvic computed tomography.

Non-contrast pelvic computed tomography (CT) can detect severe iliac artery calcifications that present technical contraindications to kidney transplantation (TCT). We screened 454 asymptomatic patients with a history of any of the following: hemodialysis >10 years, diabetes mellitus >20 years, coronary artery disease (CAD) with percutaneous or surgical interventions, carotid disease, diabetes with below-/above-knee amputations, and heart-kidney transplantation candidacy. Patients with normal dorsalis pedis and/or tibialis posterior pulses were not screened. A total of 8.4% had severe calcifications with TCT; CT determined laterality for implantation in 13.9%. No patients with the following characteristics were classified as TCT: age <40 years, hemodialysis >10 years, carotid arterial disease, prior lower extremity amputation, or heart-kidney transplantation candidacy. CAD was associated with TCT in univariate though not multivariate analysis. Limiting screening to patients >40 years, with DM >20 years, or with CAD, 9.8% had a TCT and CT determined transplant laterality in 14.2%. Screening for severe iliac artery calcifications is useful for selected kidney transplantation candidates over age 40. It can assist with laterality choice or surgeon determination of TCT. Cost and radiation exposure risks should be weighed against the morbidity risks from unnecessary surgery.

The Evolution of Transplantation From Saving Lives to Fertility Treatment: DUETS (Dallas UtErus Transplant Study).

OBJECTIVE: We report the results of the first 20 uterus transplants performed in our institution. SUMMARY BACKGROUND DATA: Uterus transplantation (UTx) aims at giving women affected by absolute uterine-factor infertility the possibility of carrying their own pregnancy. UTx has evolved from experimental to an established surgical procedure. METHODS: The Dallas Uterus Transplant Study (DUETS) program started in 2016. The uterus was transplanted in orthotopic position with vascular anastomoses to the external iliac vessels and removed when 1 or 2 live births were achieved. Immunosuppression lasted only for the duration of the uterus graft. RESULTS: Twenty women, median age 29.7 years, enrolled in the study, with 10 in phase 1 and 10 in phase 2. All but 2 recipients had a congenital absence of the uterus. Eighteen recipients received uteri from living donors and 2 from deceased donors. In phase 1, 50% of recipients had a technically successful uterus transplant, compared to 90% in phase 2. Four recipients with a technical success in phase 1 have delivered 1 or 2 babies, and the fifth recipient with a technical success is >30 weeks pregnant. In phase 2, 2 recipients have delivered healthy babies and 5 are pregnant. CONCLUSIONS: UTx is a unique type of transplant; whose only true success is a healthy child birth. Based on results presented here, involving refinement of the surgical technique and donor selection process, UTx is now an established solution for absolute uterine-factor infertility.

Coxiella burnetii effector CvpB modulates phosphoinositide metabolism for optimal vacuole development.

The Q fever bacterium Coxiella burnetii replicates inside host cells within a large Coxiella-containing vacuole (CCV) whose biogenesis relies on the Dot/Icm-dependent secretion of bacterial effectors. Several membrane trafficking pathways contribute membranes, proteins, and lipids for CCV biogenesis. These include the endocytic and autophagy pathways, which are characterized by phosphatidylinositol 3-phosphate [PI(3)P]-positive membranes. Here we show that the C. burnetii secreted effector Coxiella vacuolar protein B (CvpB) binds PI(3)P and phosphatidylserine (PS) on CCVs and early endosomal compartments and perturbs the activity of the phosphatidylinositol 5-kinase PIKfyve to manipulate PI(3)P metabolism. CvpB association to early endosome triggers vacuolation and clustering, leading to the channeling of large PI(3)P-positive membranes to CCVs for vacuole expansion. At CCVs, CvpB binding to early endosome- and autophagy-derived PI(3)P and the concomitant inhibition of PIKfyve favor the association of the autophagosomal machinery to CCVs for optimal homotypic fusion of the Coxiella-containing compartments. The importance of manipulating PI(3)P metabolism is highlighted by mutations in cvpB resulting in a multivacuolar phenotype, rescuable by gene complementation, indicative of a defect in CCV biogenesis. Using the insect model Galleria mellonella, we demonstrate the in vivo relevance of defective CCV biogenesis by highlighting an attenuated virulence phenotype associated with cvpB mutations.

Prevalence and outcomes of cystic lesions of the transplant pancreas: The University of Wisconsin Experience.

Literature on the behavior of cystic lesions in pancreas transplants is scarce, and hence a better understanding is warranted. Data on recipients and their respective donors that underwent simultaneous kidney and pancreas, pancreas transplant alone, and pancreas after kidney between 1994 and 2015 were reviewed (n = 1185). Cystic lesions of the transplant pancreas developed in 22 patients (1.8%): 12 pseudocysts, 2 cysts/remnants, 4 intraductal papillary mucinous neoplasms (IPMN), 2 adenocarcinomas, 1 low-grade intraepithelial pancreatic neoplasia, and 1 case of polycystic kidney disease. The median size was 3.6 cm (1.6-5.5 cm), and occurred at a median time of 65.5 months (2-183 months) posttransplant. The median age of the graft at time of diagnosis was 42 years (25.7-54.5), with 17 of 22 grafts (77%) functioning at time of diagnosis. Triggers for investigation were elevations in pancreatic enzymes, re-admissions for abdominal pain, and incidentalomas. High-resolution imaging and diagnostic biopsy/aspiration with ancillary tests were the main diagnostic tests. Most pseudocysts were managed by percutaneous drainage, and although no firm inference can be made from such a small series, we have observed that the behavior and management of IPMN and adenocarcinoma in the pancreas graft appears congruent to that of the native pancreas.

Intraspecific ecological niche divergence and reproductive shifts foster cytotype displacement and provide ecological opportunity to polyploids.

Background and Aims: Niche divergence between polyploids and their lower ploidy progenitors is one of the primary mechanisms fostering polyploid establishment and adaptive divergence. However, within-species chromosomal and reproductive variability have usually been neglected in community ecology and biodiversity analyses even though they have been recognized to play a role in the adaptive diversification of lineages. Methods: We used Paspalum intermedium, a grass species with diverging genetic systems (diploidy vs. autopolyploidy, allogamy vs. autogamy and sexuality vs. apomixis), to recognize the causality of biogeographic patterns, adaptation and ecological flexibility of cytotypes. Chromosome counts and flow cytometry were used to characterize within-species genetic systems diversity. Environmental niche modelling was used to evaluate intraspecific ecological attributes associated with environmental and climatic factors and to assess correlations among ploidy, reproductive modes and ecological conditions ruling species' population dynamics, range expansion, adaptation and evolutionary history. Key Results: Two dominant cytotypes non-randomly distributed along local and regional geographical scales displayed niche differentiation, a directional shift in niche optima and signs of disruptive selection on ploidy-related ecological aptitudes for the exploitation of environmental resources. Ecologically specialized allogamous sexual diploids were found in northern areas associated with higher temperature, humidity and productivity, while generalist autogamous apomictic tetraploids occurred in southern areas, occupying colder and less productive environments. Four localities with a documented shift in ploidy and four mixed populations in a zone of ecological transition revealed an uneven replacement between cytotypes. Conclusions: Polyploidy and contrasting reproductive traits between cytotypes have promoted shifts in niche optima, and increased ecological tolerance and niche divergence. Ecologically specialized diploids maintain cytotype stability in core areas by displacing tetraploids, while broader ecological preferences and a shift from sexuality to apomixis favoured polyploid colonization in peripheral areas where diploids are displaced, and fostered the ecological opportunity for autotetraploids supporting range expansion to open southern habitats.

Identification of OmpA, a Coxiella burnetii protein involved in host cell invasion, by multi-phenotypic high-content screening.

Coxiella burnetii is the agent of the emerging zoonosis Q fever. This pathogen invades phagocytic and non-phagocytic cells and uses a Dot/Icm secretion system to co-opt the endocytic pathway for the biogenesis of an acidic parasitophorous vacuole where Coxiella replicates in large numbers. The study of the cell biology of Coxiella infections has been severely hampered by the obligate intracellular nature of this microbe, and Coxiella factors involved in host/pathogen interactions remain to date largely uncharacterized. Here we focus on the large-scale identification of Coxiella virulence determinants using transposon mutagenesis coupled to high-content multi-phenotypic screening. We have isolated over 3000 Coxiella mutants, 1082 of which have been sequenced, annotated and screened. We have identified bacterial factors that regulate key steps of Coxiella infections: 1) internalization within host cells, 2) vacuole biogenesis/intracellular replication, and 3) protection of infected cells from apoptosis. Among these, we have investigated the role of Dot/Icm core proteins, determined the role of candidate Coxiella Dot/Icm substrates previously identified in silico and identified additional factors that play a relevant role in Coxiella pathogenesis. Importantly, we have identified CBU_1260 (OmpA) as the first Coxiella invasin. Mutations in ompA strongly decreased Coxiella internalization and replication within host cells; OmpA-coated beads adhered to and were internalized by non-phagocytic cells and the ectopic expression of OmpA in E. coli triggered its internalization within cells. Importantly, Coxiella internalization was efficiently inhibited by pretreating host cells with purified OmpA or by incubating Coxiella with a specific anti-OmpA antibody prior to host cell infection, suggesting the presence of a cognate receptor at the surface of host cells. In summary, we have developed multi-phenotypic assays for the study of host/pathogen interactions. By applying our methods to Coxiella burnetii, we have identified the first Coxiella protein involved in host cell invasion.