Pseudomonas effector AvrB is a glycosyltransferase that rhamnosylates plant guardee protein RIN4.

The plant pathogen Pseudomonas syringae encodes a type III secretion system avirulence effector protein, AvrB, that induces a form of programmed cell death called the hypersensitive response in plants as a defense mechanism against systemic infection. Despite the well-documented catalytic activities observed in other Fido (Fic, Doc, and AvrB) proteins, the enzymatic activity and target substrates of AvrB have remained elusive. Here, we show that AvrB is an unprecedented glycosyltransferase that transfers rhamnose from UDP-rhamnose to a threonine residue of the Arabidopsis guardee protein RIN4. We report structures of various enzymatic states of the AvrB-catalyzed rhamnosylation reaction of RIN4, which reveal the structural and mechanistic basis for rhamnosylation by a Fido protein. Collectively, our results uncover an unexpected reaction performed by a prototypical member of the Fido superfamily while providing important insights into the plant hypersensitive response pathway and foreshadowing more diverse chemistry used by Fido proteins and their substrates.

Gene Replacement by a Selectable Marker in the Filamentous FungusMagnaporthe oryzae.

Magnaporthe oryzaeis a filamentous fungus responsible for the detrimental rice blast disease afflicting rice crops worldwide. For years, M. oryzae has served as an excellent model organism to study plant pathogen interactions due to its sequenced genome, its amenability to functional genetics, and its capacity to be tracked in laboratory settings. As such, techniques to genetically manipulate M. oryzae for gene deletion range from genome editing via CRISPR-Cas9 to gene replacement through homologous recombination. This protocol focuses on detailing how to perform gene replacement in the model organism, M. oryzae, through a split marker method. This technique relies on replacing the open reading frame of a gene of interest with a gene conferring resistance to a specific selectable chemical, disrupting the transcription of the gene of interest and generating a knockout mutant M. oryzae strain. Key features Comprehensive overview of primer design, PEG-mediated protoplast transformation, and fungal DNA extraction for screening.

The Phantom Menace: latest findings on effector biology in the rice blast fungus.

Magnaporthe oryzae is a hemibiotrophic fungus responsible for the economically devastating and recalcitrant rice blast disease. However, the blast fungus is not only restricted to rice plants as it can also infect wheat, millet, and other crops. Despite previous outstanding discoveries aimed to understand and control the disease, the fungus remains one of the most important pathogens that threatens global food security. To cause disease, M. oryzae initiates morphological changes to attach, penetrate, and colonize rice cells, all while suppressing plant immune defenses that would otherwise hinder its proliferation. As such, M. oryzae actively secretes a battery of small proteins called "effectors" to manipulate host machinery. In this review, we summarize the latest findings in effector identification, expression, regulation, and functionality. We review the most studied effectors and their roles in pathogenesis. Additionally, we discern the current methodologies to structurally catalog effectors, and we highlight the importance of climate change and its impact on the future of rice blast disease.

Regulating Death and Disease: Exploring the Roles of Metacaspases in Plants and Fungi.

Identified over twenty years ago and distantly related to animal caspases are a group of cysteine proteases known as metacaspases. Throughout the years, much like caspase roles in metazoans, metacaspases have been shown to be involved in regulating cellular death in non-metazoan organisms. Yet, continued research on metacaspases describes these proteins as intricate and multifunctional, displaying striking diversity on distinct biological functions. In this review, we intend to describe the recent advances in our understanding of the divergence of metacaspase functionality in plants and fungi. We will dissect the duality of metacaspase activity in the context of plant-pathogen interactions, providing a unique lens from which to characterize metacaspases in the development, immunity, and stress responses of plants, and the development and virulence of fungi. Furthermore, we explore the evolutionary trajectory of fungal metacaspases to delineate their structure and function. Bridging the gap between metacaspase roles in immunity and pathogenicity of plant-pathogen interactions can enable more effective and targeted phytopathogen control efforts to increase production of globally important food crops. Therefore, the exploitation and manipulation of metacaspases in plants or fungi represent new potential avenues for developing mitigation strategies against plant pathogens.

Role of Two Metacaspases in Development and Pathogenicity of the Rice Blast Fungus Magnaporthe oryzae.

Rice blast disease caused by Magnaporthe oryzae is a devastating disease of cultivated rice worldwide. Infections by this fungus lead to a significant reduction in rice yields and threats to food security. To gain better insight into growth and cell death in M. oryzae during infection, we characterized two predicted M. oryzae metacaspase proteins, MoMca1 and MoMca2. These proteins appear to be functionally redundant and can complement the yeast Yca1 homologue. Biochemical analysis revealed that M. oryzae metacaspases exhibited Ca2+-dependent caspase activity in vitro Deletion of both MoMca1 and MoMca2 in M. oryzae resulted in reduced sporulation, delay in conidial germination, and attenuation of disease severity. In addition, the double ΔMomca1mca2 mutant strain showed increased radial growth in the presence of oxidative stress. Interestingly, the ΔMomca1mca2 strain showed an increased accumulation of insoluble aggregates compared to the wild-type strain during vegetative growth. Our findings suggest that MoMca1 and MoMca2 promote the clearance of insoluble aggregates in M. oryzae, demonstrating the important role these metacaspases have in fungal protein homeostasis. Furthermore, these metacaspase proteins may play additional roles, like in regulating stress responses, that would help maintain the fitness of fungal cells required for host infection.IMPORTANCEMagnaporthe oryzae causes rice blast disease that threatens global food security by resulting in the severe loss of rice production every year. A tightly regulated life cycle allows M. oryzae to disarm the host plant immune system during its biotrophic stage before triggering plant cell death in its necrotrophic stage. The ways M. oryzae navigates its complex life cycle remain unclear. This work characterizes two metacaspase proteins with peptidase activity in M. oryzae that are shown to be involved in the regulation of fungal growth and development prior to infection by potentially helping maintain fungal fitness. This study provides new insights into the role of metacaspase proteins in filamentous fungi by illustrating the delays in M. oryzae morphogenesis in the absence of these proteins. Understanding the mechanisms by which M. oryzae morphology and development promote its devastating pathogenicity may lead to the emergence of proper methods for disease control.

Cardiopulmonary resuscitation and skill retention in emergency physicians.

STUDY OBJECTIVES: The American Heart Association (AHA) recently established the Resuscitation Quality Improvement (RQI) program, which requires physicians to perform quarterly cardiopulmonary resuscitation (CPR) skill checks. The aim of this study was to determine if timing of last training impacted skill performance of emergency physicians. METHODS: A convenience sample of emergency medicine (EM) physicians was asked to complete a Basic Life Support (BLS) scenario on a manikin. Participants passed the scenario if they successfully performed high-quality CPR. Participants completed a survey to assess clinical experience and timing of prior BLS training. Outcomes were comparisons of skills check pass rates for physicians recently trained in BLS (≤90 days) and those trained >90 days ago and those trained >2 years ago. RESULTS: A total of 113 individuals were included in the study: 87 attending physicians and 26 residents. Overall 92.9% correctly performed CPR with the proper assessment, compression rate, compression depth and rescue breaths. There was no difference between success rates in EM physicians who had BLS training within 90 days (91.7%) and physicians who had not had BLS within 90 days, (93.1%). (p = 1.00) There was no difference in the pass rate of those trained within 90 days (91.7%) to those trained >2 years ago (90.9%) (95CI 0.088, 0.096). CONCLUSION: There was no difference between delivery of high-quality CPR in EM physicians who had recent BLS training and those who did not.

Cerebral blood flow changes during palpation of external airway structures in healthy volunteers.

INTRODUCTION: Previous studies demonstrate increased intracranial pressure (ICP) during direct laryngoscopy in patients with traumatic brain injury (TBI). Worse outcomes in TBI have been associated with increased ICP. It remains unclear if the same effect occurs during cricothyrotomy. We evaluated changes in cerebral blood flow and hemodynamic changes that occurred during preparation for cricothyrotomy in healthy volunteers. METHODS: An emergency medicine trainee performed routine anatomical procedural palpation with simultaneous transcranial doppler (TCD) measurements of cerebral blood flow velocities (CBFV) from bilateral middle cerebral arteries (MCAs). Mean arterial pressure (MAP) and heart rate (HR) were recorded throughout event. Our primary outcome was changes in pulsatility index (PI) and CBFV by TCD during palpation. TCD measurements were used as a surrogate for ICP. RESULTS: We enrolled 20 healthy volunteers for this study. No significant differences were found in pulsatility index [Right MCA -0.02 (95% confidence interval, -0.09 to 0.06), left MCA -0.02 (95% confidence interval, -0.011 to 0.07)] or mean CBFV [right MCA -0.70 mm/s (95% confidence interval, -10.15 to 8.75) left MCA -1.20 mm/s (95% confidence interval, -10.68 to 8.28)] during palpation. No significant change in HR was found [-1.1 bpm ((95% confidence interval, -2.4 to 0.1)]. A change in MAP was observed [1.3 mmHg (95% confidence interval, -0.1 to 2.4)]. CONCLUSIONS: In healthy individuals, no clinically significant change in cerebral blood flow velocities, ICP, or change heart rate was observed during palpation for cricothyrotomy.

A distinct inhibitory mechanism of the V-ATPase by Vibrio VopQ revealed by cryo-EM.

The Vibrio parahaemolyticus T3SS effector VopQ targets host-cell V-ATPase, resulting in blockage of autophagic flux and neutralization of acidic compartments. Here, we report the cryo-EM structure of VopQ bound to the Vo subcomplex of the V-ATPase. VopQ inserts into membranes and forms an unconventional pore while binding directly to subunit c of the V-ATPase membrane-embedded subcomplex Vo. We show that VopQ arrests yeast growth in vivo by targeting the immature Vo subcomplex in the endoplasmic reticulum (ER), thus providing insight into the observation that VopQ kills cells in the absence of a functional V-ATPase. VopQ is a bacterial effector that has been discovered to inhibit a host-membrane megadalton complex by coincidentally binding its target, inserting into a membrane and disrupting membrane potential. Collectively, our results reveal a mechanism by which bacterial effectors modulate host cell biology and provide an invaluable tool for future studies on V-ATPase-mediated membrane fusion and autophagy.

Genetic evidence for Magnaporthe oryzae vitamin B3 acquisition from rice cells.

Following penetration, the devastating rice blast fungus Magnaporthe oryzae, like some other important eukaryotic phytopathogens, grows in intimate contact with living plant cells before causing disease. Cell-to-cell growth during this biotrophic growth stage must involve nutrient acquisition, but experimental evidence for the internalization and metabolism of host-derived compounds is exceedingly sparse. This striking gap in our knowledge of the infection process undermines accurate conceptualization of the plant-fungal interaction. Here, through our general interest in Magnaporthe metabolism and with a specific focus on the signalling and redox cofactor nicotinamide adenine dinucleotide (NAD), we deleted the M. oryzae QPT1 gene encoding quinolinate phosphoribosyltransferase, catalyst of the last step in de novo NAD biosynthesis from tryptophan. We show how QPT1 is essential for axenic growth on minimal media lacking nicotinic acid (NA, an importable NAD precursor). However, Δqpt1 mutant strains were fully pathogenic, indicating de novo NAD biosynthesis is dispensable for lesion expansion following invasive hyphal growth in leaf tissue. Because overcoming the loss of de novo NAD biosynthesis in planta can only occur if importable NAD precursors (which solely comprise the NA, nicotinamide and nicotinamide riboside forms of vitamin B3) are accessible, we unexpectedly but unequivocally demonstrate that vitamin B3 can be acquired from the host and assimilated into Magnaporthe metabolism during growth in rice cells. Our results furnish a rare, experimentally determined example of host nutrient acquisition by a fungal plant pathogen and are significant in expanding our knowledge of events at the plant-fungus metabolic interface.

A Bacterial Effector Mimics a Host HSP90 Client to Undermine Immunity.

The molecular chaperone HSP90 facilitates the folding of several client proteins, including innate immune receptors and protein kinases. HSP90 is an essential component of plant and animal immunity, yet pathogenic strategies that directly target the chaperone have not been described. Here, we identify the HopBF1 family of bacterial effectors as eukaryotic-specific HSP90 protein kinases. HopBF1 adopts a minimal protein kinase fold that is recognized by HSP90 as a host client. As a result, HopBF1 phosphorylates HSP90 to completely inhibit the chaperone's ATPase activity. We demonstrate that phosphorylation of HSP90 prevents activation of immune receptors that trigger the hypersensitive response in plants. Consequently, HopBF1-dependent phosphorylation of HSP90 is sufficient to induce severe disease symptoms in plants infected with the bacterial pathogen, Pseudomonas syringae. Collectively, our results uncover a family of bacterial effector kinases with toxin-like properties and reveal a previously unrecognized betrayal mechanism by which bacterial pathogens modulate host immunity.

The Prehospital Trauma Registry Experience With Intraosseous Access.

BACKGROUND: Peripheral intravenous (IV) cannulation is often difficult to obtain in a patient with hemorrhagic shock, delaying the appropriate resuscitation of critically ill patients. Intraosseous (IO) access is an alternative method. To date, few data exist on use of this procedure by ground forces in Afghanistan. Here, we compare patient characteristics and concomitant interventions among patients undergoing IO access versus those undergoing IV access only. METHODS: We obtained data from the Prehospital Trauma Registry (PHTR). When possible, patients were linked to the Department of Defense Trauma Registry for outcome data. To develop the cohorts, we searched for all patients with documented IO or IV access placement. Those with both IO and IV access documented were placed in the IO group. RESULTS: Of the 705 available patients in the PHTR, we identified 55 patients (7.8% of the population) in the IO group and 432 (61.3%) in the IV group. Among patients with documentation of access location, the most common location was the tibia (64.3%; n = 18). Compared with patients with IV access, those who underwent IO access had higher urgent evacuation rates (90.9% versus 72.4%; p = .01) and air evacuation rates (58.2% versus 14.8%; p < .01). The IO cohort had significantly higher rates of interventions for hypothermia, chest seals, chest tubes, needle decompressions, and tourniquets, but a significantly lower rate of analgesic administration (ρ ≤ .05). CONCLUSION: Within the registry, IO placement was relatively low (<10%) and used in casualties who received several other life-saving interventions at a higher rate than casualties who had IV access. Incidentally, lower proportions of analgesia administration were detected in the IO group compared with the IV group, despite higher intervention rates.

Battlefield Analgesia: Adherence to Tactical Combat Casualty Care Guidelines.

BACKGROUND: Low rates of prehospital analgesia, as recommended by Tactical Combat Casualty Care (TCCC) guidelines, have been demonstrated in the Joint Theaters combat setting. The reasons for this remain unclear. This study expands on previous reports by evaluating a larger prehospital dataset for determinants of analgesia administration. METHODS: This was part of an approved quality assurance project evaluating adherence to TCCC guidelines across multiple modalities. Data were from the Prehospital Trauma Registry, which existed from January 2013 through September 2014, and comprises data from TCCC cards, Department of Defense 1380 forms, and after-action reports to provide real-time feedback to units on prehospital medical care. RESULTS: Of 705 total patient encounters, there were 501 documented administrations of analgesic medications given to 397 patients. Of these events, 242 (34.3%) were within TCCC guidelines. Special Operations Command had the highest rate of overall adherence, but rates were still low (68.5%). Medical officers had the highest rates of overall administration. The low rates of administration and adherence persisted across all subgroups. CONCLUSION: Rates of analgesia administration remained low overall and in subgroup analyses. Medical officers appeared to have higher rates of compliance with TCCC guidelines for analgesia administration, but overall adherence to TCCC guidelines was low. Future research will be aimed at finding methods to improve administration and adherence rates.

Prehospital Resuscitation Performed on Hypotensive Trauma Patients in Afghanistan: The Prehospital Trauma Registry Experience.

INTRODUCTION: Hemorrhage is the leading cause of potentially preventable death on the battlefield. Hypotension in the setting of trauma portends a higher rate of mortality. We describe the interventions for trauma-related hypotension performed in the prehospital combat setting in accordance with Tactical Combat Casualty Care (TCCC) guidelines. MATERIALS AND METHODS: We searched the Prehospital Trauma Registry for casualties from January 2013 to September 2014. Within that group, we searched for all casualties with documented hypotension by either measured systolic blood pressure ≤90 mmHg or a weak or absent radial pulse documented by the prehospital provider. We used descriptive statistics to analyze the interventions performed in our study sample. RESULTS: Of the 705 casualties available for query, 134 (19.0%) casualties with documented hypotension met inclusion criteria. Most casualties with hypotension had an alert mental status (70.1%), had a medical officer in their chain of care (59.0%), were Afghan (64.2%), and evacuated on an urgent status (78.4%). Explosives were the most frequent mechanism of injury (50.7%). There were 42 fluid administrations documented on 33 (24.6%) casualties. The most common fluid administered was normal saline (52.4%) followed by hetastarch solution (33.3%). There was one documented use of a fluid warmer in this cohort. One subject received four units of packed red blood cells. No other casualties had documented blood product administration. There were no documented administrations of PlasmaLyte. There were four casualties that received lactated Ringer's. CONCLUSION: Most casualties with documented hypotension after trauma in the Prehospital Trauma Registry did not receive prehospital blood or fluid intervention. Of the interventions performed, most did not match with contemporary TCCC guidelines.

Prehospital Administration of Antibiotic Prophylaxis for Open Combat Wounds in Afghanistan: 2013-2014.

BACKGROUND: Military operations place injured Servicemembers at high risk for open wounds. Austere environments and initial wound contamination increase the risk for infection. Wound infections continue to cause significant morbidity among injured Servicemembers. Limited evidence suggests that early antibiotic therapy for open wounds reduces infection rates. METHODS: We obtained data from the Prehospital Trauma Registry (PHTR) from January 2013 through September 2014. This database includes data from Tactical Combat Casualty Care (TCCC) cards, Department of Defense 1380 forms, and after-action reports to provide near-real-time feedback to units on prehospital medical care. We evaluated whether patients with open wounds received antibiotics in accordance with TCCC guidelines. Low adherence was defined at less than 80%. RESULTS: In this data set, overall, prefixed facility providers administered antibiotics to 54.0% of patients with an open combat wound. Of the antibiotics given, 11.1% were within TCCC guidelines. The relatively low administration and adherence rates persisted across subgroup analyses. CONCLUSION: Overall, relatively few patients with open combat wounds receive antibiotic administration as recommended by TCCC guidelines. In the group that received antibiotics, few received the specific antibiotics recommended by TCCC guidelines. The development of strategies to improve adherence to these TCCC recommendations is a research priority.

Emergency Department Intubation Success With Succinylcholine Versus Rocuronium: A National Emergency Airway Registry Study.

STUDY OBJECTIVE: Although both succinylcholine and rocuronium are used to facilitate emergency department (ED) rapid sequence intubation, the difference in intubation success rate between them is unknown. We compare first-pass intubation success between ED rapid sequence intubation facilitated by succinylcholine versus rocuronium. METHODS: We analyzed prospectively collected data from the National Emergency Airway Registry, a multicenter registry collecting data on all intubations performed in 22 EDs. We included intubations of patients older than 14 years who received succinylcholine or rocuronium during 2016. We compared the first-pass intubation success between patients receiving succinylcholine and those receiving rocuronium. We also compared the incidence of adverse events (cardiac arrest, dental trauma, direct airway injury, dysrhythmias, epistaxis, esophageal intubation, hypotension, hypoxia, iatrogenic bleeding, laryngoscope failure, laryngospasm, lip laceration, main-stem bronchus intubation, malignant hyperthermia, medication error, pharyngeal laceration, pneumothorax, endotracheal tube cuff failure, and vomiting). We conducted subgroup analyses stratified by paralytic weight-based dose. RESULTS: There were 2,275 rapid sequence intubations facilitated by succinylcholine and 1,800 by rocuronium. Patients receiving succinylcholine were younger and more likely to undergo intubation with video laryngoscopy and by more experienced providers. First-pass intubation success rate was 87.0% with succinylcholine versus 87.5% with rocuronium (adjusted odds ratio 0.9; 95% confidence interval 0.6 to 1.3). The incidence of any adverse event was also comparable between these agents: 14.7% for succinylcholine versus 14.8% for rocuronium (adjusted odds ratio 1.1; 95% confidence interval 0.9 to 1.3). We observed similar results when they were stratified by paralytic weight-based dose. CONCLUSION: In this large observational series, we did not detect an association between paralytic choice and first-pass rapid sequence intubation success or peri-intubation adverse events.

Rise of a Cereal Killer: The Biology of Magnaporthe oryzae Biotrophic Growth.

The rice blast fungus, Magnaporthe oryzae, causes one of the most destructive diseases of cultivated rice in the world. Infections caused by this recalcitrant pathogen lead to the annual destruction of approximately 10-30% of the rice harvested globally. The fungus undergoes extensive developmental changes to be able to break into plant cells, build elaborate infection structures, and proliferate inside host cells without causing visible disease symptoms. From a molecular standpoint, we are still in the infancy of understanding how M. oryzae manipulates the host during this complex multifaceted infection. Here, we describe recent advances in our understanding of the cell biology of M. oryzae biotrophic interaction and key molecular factors required for the disease establishment in rice cells.

A randomized cross-over study comparing surgical cricothyrotomy techniques by combat medics using a synthetic cadaver model.

OBJECTIVE: Cricothyrotomy is a complex procedure with a high rate of complications including failure to cannulate and injury to adjacent anatomy. The Control-Cric™ System and QuickTrach II™ represent two novel devices designed to optimize success and minimize complications with this procedure. This study compares these two devices against a standard open surgical technique. METHODS: We conducted a randomized crossover study of United States Army combat medics using a synthetic cadaver model. Participants performed a surgical cricothyrotomy using the standard open surgical technique, Control-Cric™ System, and QuickTrach II™ device in a random order. The primary outcome was time to successful cannulation. The secondary outcome was first-attempt success. We also surveyed participants after performing the procedures as to their preferences. RESULTS: Of 70 enrolled subjects, 65 completed all study procedures. Of those that successfully cannulated, the mean times to cannulation were comparable for all three methods: standard 51.0s (95% CI 45.2-56.8), QuickTrach II™ 39.8s (95% CI 31.4-48.2) and the Cric-Control™ 53.6 (95% CI 45.7-61.4). Cannulation failure rates were not significantly different: standard 6.2%, QuickTrach II™ 13.9%, Cric-Control™ 18.5% (p=0.106). First pass success rates were also similar (93.4%, 91.1%, 88.7%, respectively, p=0.670). Of respondents completing the post-study survey, a majority (52.3%) preferred the QuickTrach II™ device. CONCLUSIONS: We identified no significant differences between the three cricothyrotomy techniques with regards to time to successful cannulation or first-pass success.

A 12-month descriptive analysis of emergency intubations at Brooke Army Medical Center: a National Emergency Airway Registry study.

Emergency airway management is a critical skill for military healthcare providers. Our goal was to describe the Emergency Department (ED) intubations at Brooke Army Medical Center (BAMC) over a 12-month period. MATERIAL AND METHODS: Physicians performing endotracheal intubations in the BAMC ED complete data collection forms for each intubation event as part of the National Emergency Airway Registry, including patient demographics, intubation techniques, success and failure rates, adverse events, and patient disposition. We cross-referenced these forms against the numbers of intubation events reported in the ED nursing daily reports to ensure capture of all intubations. Providers completed forms for every intubation within 6 weeks of the procedure. We analyzed data from March 28, 2016, to March 27, 2017. RESULTS: During the study period, providers performed 259 intubations in the BAMC ED. Reasons for intubation were related to trauma for 184 patients (71.0%) and medical conditions for 75 patients (29.0%). Overall, first-attempt success was 83.0%. Emergency medicine residents performed a majority of first attempts (95.0%). Most common devices chosen on first attempt were a video laryngoscope for 143 patients (55.2%) and a direct laryngoscope for 115 patients (44.4%). One patient underwent cricothyrotomy. The 2 most common induction agents were ketamine (59.8%; 95% CI, 55.2%-67.4%) and etomidate (19.3%; 95% CI, 14.7%-24.7%). The most common neuromuscular blocking agents were rocuronium (62.9%; 95% CI, 56.7%-68.8%) and succinylcholine (18.9%; 95% CI, 14.3%-24.2%). CONCLUSION: In the BAMC ED, emergency intubation most commonly occurred for trauma indications using video laryngoscopy with a high first-pass success.

Chest Seal Placement for Penetrating Chest Wounds by Prehospital Ground Forces in Afghanistan.

BACKGROUND: Thoracic trauma represents 5% of all battlefield injuries. Communicating pneumothoraces resulting in tension physiology remain an important etiology of prehospital mortality. In addressing penetrating chest trauma, current Tactical Combat Casualty Care (TCCC) guidelines advocate the immediate placement of a vented chest seal device. Although the Committee on TCCC (CoTCCC) has approved numerous chest seal devices for battlefield use, few data exist regarding their use in a combat zone setting. OBJECTIVE: To evaluate adherence to TCCC guidelines for chest seal placement among personnel deployed to Afghanistan. METHODS: We obtained data from the Prehospital Trauma Registry (PHTR). Joint Trauma System personnel linked patients to the Department of Defense Trauma Registry, when available, for outcome data upon reaching a fixed facility. RESULTS: In the PHTR, we identified 62 patients with documented gunshot wound (GSW) or puncture wound trauma to the chest. The majority (74.2%; n = 46) of these were due to GSW, with the remainder either explosive-based puncture wounds (22.6%; n = 14) or a combination of GSW and explosive (3.2%; n = 2). Of the 62 casualties with documented GSW or puncture wounds, 46 (74.2%) underwent chest seal placement. Higher proportions of patients with medical officers in their chain of care underwent chest seal placement than those that did not (63.0% versus 37.0%). The majority of chest seals placed were not vented. CONCLUSION: Of patients with a GSW or puncture wound to the chest, 74.2% underwent chest seal placement. Most of the chest seals placed were not vented in accordance with guidelines, despite the guideline update midway through the study period. These data suggest the need to improve predeployment training on TCCC guidelines and matching of the Army logistical supply chain to the devices recommended by the CoTCCC.