20 research outputs found
The effects of vaccination and immunity on bacterial infection dynamics in vivo.
Salmonella enterica infections are a significant global health issue, and development of vaccines against these bacteria requires an improved understanding of how vaccination affects the growth and spread of the bacteria within the host. We have combined in vivo tracking of molecularly tagged bacterial subpopulations with mathematical modelling to gain a novel insight into how different classes of vaccines and branches of the immune response protect against secondary Salmonella enterica infections of the mouse. We have found that a live Salmonella vaccine significantly reduced bacteraemia during a secondary challenge and restrained inter-organ spread of the bacteria in the systemic organs. Further, fitting mechanistic models to the data indicated that live vaccine immunisation enhanced both the bacterial killing in the very early stages of the infection and bacteriostatic control over the first day post-challenge. T-cell immunity induced by this vaccine is not necessary for the enhanced bacteriostasis but is required for subsequent bactericidal clearance of Salmonella in the blood and tissues. Conversely, a non-living vaccine while able to enhance initial blood clearance and killing of virulent secondary challenge bacteria, was unable to alter the subsequent bacterial growth rate in the systemic organs, did not prevent the resurgence of extensive bacteraemia and failed to control the spread of the bacteria in the body.This work was supported by the Biotechnology and Biological Sciences Research Council [grant number BB/I002189/1].This is the published manuscript. It was originally published by PLOS One here: http://www.plospathogens.org/article/info%3Adoi%2F10.1371%2Fjournal.ppat.1004359
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The Suicide Prevention, Depression Awareness, and Clinical Engagement Program for Faculty and Residents at the University of California, Davis Health.
ObjectiveThe objective of the study is to present results of a depression and suicide screening and treatment referral program for physicians at an academic medical center.MethodsAn anonymous web-based screening questionnaire was sent to all physicians at a large academic center. Responses were classified as indicating either high, moderate, or low risk for depression and suicide. Physicians at high and moderate risk were contacted by a counselor through a messaging system. The counselor's message contained information on risk level and an invitation to meet in person. High-risk respondents who did not reply to the message or declined to meet received mental health resources. Respondents who met with the counselor were offered individualized treatment referrals and to participate in a 1-year follow-up of self-reports every 3 months.ResultsThe questionnaire was sent to approximately 1800 residents, fellows, and faculty from February 2013 through March 2019. A total of 639 questionnaires were received, 100 were excluded for various reasons, and 539 were used to conduct analyses (14.4% response rate). The majority of respondents were classified at moderate (333 [62%]) or high (193 [36%]) risk for depression or suicide. Eighty-three respondents were referred for mental health care, and 14 provided data for the follow-up study.ConclusionsResults of screening physicians for depression and suicide at one academic medical center highlight the challenges of engaging most of them in this activity and the satisfaction of the minority who successfully engaged in a treatment referral program