Introduction of transcatheter edge-to-edge repair in patients with congenital heart disease at a children's hospital.

BACKGROUND: Atrioventricular valve regurgitation (AVVR) is a devastating complication in children and young adults with congenital heart disease (CHD), particularly in patients with single ventricle physiology. Transcatheter edge-to-edge repair (TEER) is a rapidly expanding, minimally invasive option for the treatment of AVVR in adults that avoids the morbidity and mortality associated with open heart surgery. However, application of TEER in in CHD and in children is quite novel. We describe the development of a peri-procedural protocol including image-derived pre-intervention simulation, with successful application to four patients. AIMS: To describe the initial experience using the MitraClip system for TEER of dysfunctional systemic atrioventricular valves in patients with congential heart disease within a pediatric hospital. METHODS: A standardized screening and planning process was developed using cardiac magnetic resonance imaging, three dimensional echocardiography and both virtual and physical simulation. Procedures were performed using the MitraClip G4 system and patients were clinically followed post-intervention. RESULTS: A series of four CHD patients with at least severe AVVR were screened for suitability for TEER with the MitraClip system: three patients had single ventricle physiology and Fontan palliation, and one had repair of a common atrioventricular canal defect. Each patient had at least severe systemic AVVR and was considered at prohibitively high risk for surgical repair. Each patient underwent a standardized preprocedural screening protocol and image-derived modeling followed by the TEER procedure with successful clip placement at the intended location in all cases. CONCLUSIONS: The early results of our protocolized efforts to introduce TEER repair of severe AV valve regurgitation with MitraClip into the CHD population within our institution are encouraging. Further investigations of the use of TEER in this challenging population are warranted.

Association between missed appointments and hospitalization for child physical abuse.

Missed cases of child physical abuse (CPA) persist despite known risk factors. Prior studies have not evaluated missed medical appointments as a risk factor for CPA. The objective of this study was to determine if an association exists between missed appointments and hospitalization for CPA. We conducted a 20-year, single health system, retrospective chart review of hospitalized patients ≤36 months of age meeting International Classification of Diseases (ICD) 9/10 criteria for CPA with ≥1 scheduled appointment in our system prior to their admission. Cases were categorized as definite CPA, high likelihood, or no concern for CPA/unable to be determined. Cases identified as definite or high likelihood of CPA were matched (5:1) with controls based on age, distance to primary care provider's (PCP's) office, sex, prior hospitalization, and race. Missed appointments were compared between cases (n = 146) and controls (n = 730). A significant difference was identified between cases and controls (26 % vs 9 %, p < 0.001) for the median proportion of missed appointments. After adjusting for matched and significant covariates, there was a 3 % increase in a patient's odds of admission for CPA for every 1 % increase in missed appointments. We found an association between missed appointments and future admission for CPA. This finding has potential to assist clinicians with CPA risk stratification and future child abuse research. Limitations include single healthcare system, ICD criteria determined by research team, and narrow definition of definite CPA.

3-Dimensional Modeling Guided Transcatheter Repair of Dehisced Pulmonary Venous Baffle With Gore ASD Device.

A 38-year-old woman with sinus venosus atrial septal defect and partial anomalous return of the right upper pulmonary vein underwent a Warden procedure but experienced a large residual defect after patch dehiscence. Image-derived 3D modeling informed novel device closure with a Gore Cardioform atrial septal occluder. (Level of Difficulty: Advanced.).

Coil Embolization of a Ruptured Mycotic Coronary Artery Aneurysm in a Pediatric Patient.

Mycotic coronary artery aneurysms are rare but have a high risk of mortality. Traditional management is surgical, but percutaneous intervention can be performed in patients with high surgical risk. In this report, we describe a case of mycotic coronary aneurysm in a pediatric patient successfully managed with percutaneous coil embolization. (Level of Difficulty: Advanced.).

Performance Characteristics of a Rule-Based Electronic Health Record Algorithm to Identify Patients with Gross and Microscopic Hematuria.

BACKGROUND: Two million patients per year are referred to urologists for hematuria, or blood in the urine. The American Urological Association recently adopted a risk-stratified hematuria evaluation guideline to limit multi-phase computed tomography to individuals at highest risk of occult malignancy. OBJECTIVES: To understand population-level hematuria evaluations, we developed an algorithm to accurately identify hematuria cases from electronic health records (EHRs). METHODS: We used International Classification of Diseases (ICD)-9/ICD-10 diagnosis codes, urine color, and urine microscopy values to identify hematuria cases and to differentiate between gross and microscopic hematuria. Using an iterative process, we refined the ICD-9 algorithm on a gold standard, chart-reviewed cohort of 3,094 hematuria cases, and the ICD-10 algorithm on a 300 patient cohort. We applied the algorithm to Geisinger patients ≥35 years (n = 539,516) and determined performance by conducting chart review (n = 500). RESULTS: After applying the hematuria algorithm, we identified 51,500 hematuria cases and 488,016 clean controls. Of the hematuria cases, 11,435 were categorized as gross, 26,658 as microscopic, 12,562 as indeterminate, and 845 were uncategorized. The positive predictive value (PPV) of identifying hematuria cases using the algorithm was 100% and the negative predictive value (NPV) was 99%. The gross hematuria algorithm had a PPV of 100% and NPV of 99%. The microscopic hematuria algorithm had lower PPV of 78% and NPV of 100%. CONCLUSION: We developed an algorithm utilizing diagnosis codes and urine laboratory values to accurately identify hematuria and categorize as gross or microscopic in EHRs. Applying the algorithm will help researchers to understand patterns of care for this common condition.

Radiation Therapy in the Last Month of Life: Association With Aggressive Care at the End of Life.

CONTEXT: Half of the patients with cancer who undergo radiation therapy do so with palliative intent. OBJECTIVES: To determine the proportion of undergoing radiation in the last month of life, patient characteristics, cancer course, the type and duration of radiation, whether palliative care was involved, and the of radiation with aggressive cancer care metrics. METHODS: One thousand seven hundred twenty-seven patients who died of cancer between January 1, 2018, and December 31, 2019, were included. Demographics, cancer stage, palliative care referral, advance directives, use of home health care, radiation timing, and survival were collected. Type of radiation, course, and intent were reviewed. Chi-square analysis was utilized for categorical variables, and Kruskal-Wallis tests for continuous variables. A stepwise selection was used to build a Cox proportional hazard model. RESULTS: Two hundred thirty-three patients underwent radiation in the last month of life. Younger patients underwent radiation 67.3 years (SD 11.52) versus 69.2 years (SD 11.96). 42.6% had radiation within two weeks of death. The average fraction number was 5.5. Individuals undergoing radiation were more likely to start chemotherapy within the last 30 days of life, continue chemotherapy within two weeks of death, be admitted to the ICU, and have two or more hospitalizations or emergency room visits. Survival measured from the date of diagnosis was shorter for those undergoing radiation, 122 days (IQR 58-462) versus 474 days (IQR 225-1150). Palliative care consultations occurred later in those undergoing radiation therapy. CONCLUSION: Radiation therapy in the last month of life occurs in younger patients with rapidly progressive cancer, who are subject to more aggressive cancer care, and have late palliative care consults.

Contemporary Plural Deliberations and Perspectives in Revision Middle Ear Surgery. Causes, Outcomes and Lessons Learned.

The indications for revision middle ear surgery are inter-linked to the objectives of surgery and needs of the patient. Revision middle ear surgery is often challengingly arduous not only for the patient but for the surgeon as well. This study concentrates on the causes of failures of primary ear surgery, indications, techniques, outcomes and lessons learned in revision ear surgery. This retrospectivedescriptive study included 22 cases (12.29%) of revision surgery,with a follow up of at least one year, out of total 179 cases of middle ear surgeries performed over a period of 5 years.These revision cases included tympanoplasty, cortical mastoidectomy and modified radical mastoidectomy alongwith ossiculoplasty and scutumplasty, wherever required. Hearing improvement, closure of perforation, and prevention of recrudescence were the main outcome parameters. The overall morphologic success of revision surgery in our series was 90.90%.There was one graft failure, one attic retraction and the main complication observed was post-operative worsening of hearing.Mean postoperative pure-tone average air -bone gap (ABG) was 20.86 ± 11.29 dB compared with preoperative ABG of 29.64 ± 10.63 dB and the difference was statistically significant ( p < 0.05) with p value 0.0112 on paired t-test. Detailed knowledge and anticipation of the cause of failure is a must in preventing another failure in revision ear surgeries. Hearing preservation must be considered in a pragmatic perspective and accordingly surgical indications must complement the realistic and reasonable expectations of the patients.

Validation of the Surprise Question and the Development of a Multivariable Model.

CONTEXT: The Surprise Question (SQ) (would you be surprised if this patient died within a year?) is a prognostic variable explored in chronic illnesses. Validation is limited to sensitivity, specificity, and predictive values. OBJECTIVES: Our objective is to validate the SQ in cancer patients and develop a predictive model with additional variables. METHODS: A prospective cohort study of adult (age>18) cancer patients seen between October 1, 2019, through March 31, 2021, undergoing systemic therapies had the SQ completed by oncologists prior to each change in systemic therapy. The primary outcome was survival for one year. Secondary outcomes were predictions of survival at three, six, and nine months. Patients were grouped into negative SQ (not surprised) and positive SQ (surprised). Sensitivity, specificity, predictive values, and likelihood ratios (LR) were calculated for the SQ. Additional prognostic variables were age, gender, cancer stage, line of therapy, Charleson Comorbid Index (CCI), palliative care consultation (prior to, after the SQ, or not at all), and healthcare utilization (outpatient, inpatient, and emergency department (ED). Logistic regression and receiver operating characteristics (ROC) were used for discrimination and modeling. Akaike information criterion (AIC) was used to compare the model fit as each predictor. RESULTS: 1366 patients had 1 SQ; 784 died within a year. The SQ predicted survival at one year (P = 0.008), with a positive LR of 1.459 (95%CI 1.316-1.602) and a c-statistic of 0.565 (95%CI 0.530-0.600). Additional variables increased the c-statistic to 0.648 (95% CI 0.608-0.686). The total model best predicted survival at three months, c-statistic of 0.663 (95% CI 0.616-0.706). However, the total model c-statistic remained <0.70. CONCLUSIONS: The SQ, as a single factor, poorly predicts survival and should not be used to alter therapies. Adding additional objective variables improved prognostication, but further refinement and external validation are needed.

Incidence and Prevalence of Cough in a Rural Health System: A 20-Year Study.

OBJECTIVE: Understanding the cough population is critical to addressing clinical needs and gaps in best practice. We sought to characterize and stratify cough patients with the hypothesis that there are opportunities to improve access to care in our health system and characterize the population. METHODS: Following institutional review board exempt status, a retrospective electronic record review was performed on all patients coded with ICD-9 786.2 or ICD-10 is R05 from January 1, 2001 through December 31, 2020 at our health system. Inclusion criteria were one or more visits for cough. The subgroup with more than one visit in each of 2 years was classified as multiple encounters. Patients were characterized by sex, age at first cough encounter, number of cough encounters, smoking status, and insurance status. Results were stratified by year, calculating frequencies, and percentages. RESULTS: There were 302,284 unique patients diagnosed with cough, among 1,764,387 patients seen in our health system, representing an average incidence of 3.0% (2.7%-3.7%) and prevalence of 4.9% (3.1%-5.6%). New single encounter cough patients totaled 179,963, and new multiple encounter cough patients totaled 122,321. Of the 39,828,073 total encounters, there were 469,802 for new or existing cough (1.17%-1.73% annually). The age at initial presentation demonstrated 36.5% seen <10 years old, with an even distribution over the remaining decades of life. The majority were seen for cough once, but 23.8% of group two patients had two or more visits for cough in a year. CONCLUSION: We demonstrate a lower-than-expected incidence and prevalence of cough in our health population, suggesting challenges with access to care when compared to 10% prevalence and 3% of encounters previously documented in the literature. The study also provides a platform to explore the importance of pediatric cough, as well as population health and the longitudinal journey of cough patients in underserved areas. LEVEL OF EVIDENCE: 3 Laryngoscope, 133:1191-1196, 2023.

Improved COVID-19 detection with chest x-ray images using deep learning.

The novel coronavirus disease, which originated in Wuhan, developed into a severe public health problem worldwide. Immense stress in the society and health department was advanced due to the multiplying numbers of COVID carriers and deaths. This stress can be lowered by performing a high-speed diagnosis for the disease, which can be a crucial stride for opposing the deadly virus. A good large amount of time is consumed in the diagnosis. Some applications that use medical images like X-Rays or CT-Scans can pace up the time used in diagnosis. Hence, this paper aims to create a computer-aided-design system that will use the chest X-Ray as input and further classify it into one of the three classes, namely COVID-19, viral Pneumonia, and healthy. Since the COVID-19 positive chest X-Rays dataset was low, we have exploited four pre-trained deep neural networks (DNNs) to find the best for this system. The dataset consisted of 2905 images with 219 COVID-19 cases, 1341 healthy cases, and 1345 viral pneumonia cases. Out of these images, the models were evaluated on 30 images of each class for the testing, while the rest of them were used for training. It is observed that AlexNet attained an accuracy of 97.6% with an average precision, recall, and F1 score of 0.98, 0.97, and 0.98, respectively.

Applying computable phenotypes within a common data model to identify heart failure patients for an implantable cardiac device registry.

BACKGROUND: Use of existing data in electronic health records (EHRs) could be used more extensively to better leverage real world data for clinical studies, but only if standard, reliable processes are developed. Numerous computable phenotypes have been validated against manual chart review, and common data models (CDMs) exist to aid implementation of such phenotypes across platforms and sites. Our objective was to measure consistency between data that had previously been manually collected for an implantable cardiac device registry and CDM-based phenotypes for the condition of heart failure (HF). METHODS: Patients enrolled in an implantable cardiac device registry at two hospitals from 2013 to 2018 contributed to this analysis wherein registry data were compared to PCORnet CDM-formatted EHR data. Seven different phenotype algorithms were used to search for the presence of HF and compare the results with the registry. Sensitivity, specificity, predictive value and congruence were calculated for each phenotype. RESULTS: In the registry, 176 of 319 (55%) patients had history of HF, compared with different phenotypes estimating between 96 (30%) and 188 (59%). The least-restrictive phenotypes (any diagnosis) had high sensitivity and specificity (90%/80%), but more restrictive phenotypes had higher specificity (e.g., code present in problem list, 94%). Differences were observed using time-based criteria (e.g., days between visit diagnoses) and between participating hospitals. CONCLUSIONS: Consistency between manually-collected registry data and CDM-based phenotypes for history of HF was high overall, but use of different phenotypes impacted sensitivity and specificity, and results may differ depending on the medical condition of interest.

Sex-specific association of RAGE and HMGB1 genotype variations with susceptibility to ischemic stroke in Caucasians.

BACKGROUND: The role of genotype variants of HMGB1 and RAGE in susceptibility to acute ischemic stroke remains inconclusive. METHODS: Caucasian acute ischemic stroke patients admitted to three hospitals within a large healthcare system in the U.S. between 2009 and 2017 were reviewed. For each stroke case, three age and sex-matched non-stroke patients were identified as controls. Associations of phased-genotype data for RAGE (rs1035798, rs2070600, rs1800624, rs1800625) and HMGB1 (rs1360485, rs1045411, rs3742305, rs2249825, rs1412125) single-nucleotide-polymorphisms (SNPs) and haplotypes with stroke susceptibility were analyzed. The Benjamini-Hochberg procedure was performed. RESULTS: Collectively, 4,264 patients, 1,066 acute ischemic stroke and 3,198 controls were identified. Genotype distributions were in Hardy-Weinberg equilibrium. None of the SNPs alternate allele frequencies differed from the NCBI SNP database. No differences were found in the genotype distributions when analyzing each SNP and the two most common haplotypes in a covariate adjusted model. In a sex-specific stratification, males harboring the RAGE SNP rs1800625 AG or GG genotype had an independently increased risk for ischemic strokes compared to controls (adjusted OR = 1.27,95%CI 1.03-1.57, pa = 0.0276). After the Benjamini-Hochberg procedure, a trend towards this association remained (pBH = 0.1104). CONCLUSION: No association of RAGE and HMGB1 genotypes variations with risk for overall ischemic stroke or specific stroke subtypes could be observed. Congruent with the literature, a sex-specific role of RAGE SNPs might associate with stroke susceptibility. The functional role of the HMGB1-RAGE axis in this context warrants further exploration.

Trends in ischemic stroke outcomes in a rural population in the United States.

INTRODUCTION: The stroke mortality rate has gradually declined due to improved interventions and controlled risk factors. We investigated the associated factors and trends in recurrence and all-cause mortality in ischemic stroke patients from a rural population in the United States between 2004 and 2018. METHODS: This was a retrospective cohort study based on electronic health records (EHR) data. A comprehensive stroke database called "Geisinger NeuroScience Ischemic Stroke (GNSIS)" was built for this study. Clinical data were extracted from multiple sources, including EHR and quality data. RESULTS: The cohort included in the study comprised of 8561 consecutive ischemic stroke patients (mean age: 70.1 ± 13.9 years, men: 51.6%, 95.1% Caucasian). Hypertension was the most prevalent risk factor (75.2%). The one-year recurrence and all-cause mortality rates were 6.3% and 16.1%, respectively. Although the one-year stroke recurrence increased during the study period, the one-year stroke mortality rate decreased significantly. Age > 65 years, atrial fibrillation or flutter, heart failure, and prior ischemic stroke were independently associated with one-year all-cause mortality in stratified Cox proportional hazards model. In the Cause-specific hazard model, diabetes, chronic kidney disease and age < 65 years were found to be associated with one-year ischemic stroke recurrence. CONCLUSION: Although all-cause mortality after stroke has decreased, stroke recurrence has significantly increased in stroke patients from rural population between 2004 and 2018. Older age, atrial fibrillation or flutter, heart failure, and prior ischemic stroke were independently associated with one-year all-cause mortality while diabetes, chronic kidney disease and age less than 65 years were predictors of ischemic stroke recurrence.

Obesity and mortality after the first ischemic stroke: Is obesity paradox real?

BACKGROUND AND PURPOSE: Obesity is an established risk factor for ischemic stroke but the association of increased body mass index (BMI) with survival after ischemic stroke remains controversial. Many studies have shown that increased BMI has a "protective" effect on survival after stroke while other studies have debunked the "obesity paradox". This study aimed at examining the relationship between BMI and all-cause mortality at one year in first-time ischemic stroke patients using a large dataset extracted from different resources including electronic health records. METHODS: This was a retrospective cohort study of consecutive ischemic stroke patients captured in our Geisinger NeuroScience Ischemic Stroke (GNSIS) database. Survival in first-time ischemic stroke patients in different BMI categories was analyzed using Kaplan Meier survival curves. The predictors of mortality at one-year were assessed using a stratified Cox proportional hazards model. RESULTS: Among 6,703 first-time ischemic stroke patients, overweight and obese patients were found to have statistically decreased hazard ratio (HR) compared to the non-overweight patients (overweight patients- HR = 0.61 [95% CI, 0.52-0.72]; obese patients- HR = 0.56 [95% CI, 0.48-0.67]). Predictors with a significant increase in the hazard ratio for one-year mortality were age at the ischemic stroke event, history of neoplasm, atrial fibrillation/flutter, diabetes, myocardial infarction and heart failure. CONCLUSION: Our study results support the obesity paradox in ischemic stroke patients as shown by a significantly decreased hazard ratio for one-year mortality among overweight and obese patients in comparison to non-overweight patients.

Matrix Gla protein polymorphism rs1800801 associates with recurrence of ischemic stroke.

The MGP single nucleotide polymorphism (SNP) rs1800801 has previously been associated with recurrent ischemic stroke in a Spanish cohort. Here, we tested for association of this SNP with ischemic stroke recurrence in a North American Caucasian cohort. Acute ischemic stroke patients admitted between 10/2009 and 12/2016 at three hospitals within a large healthcare system in the northeastern United States that were enrolled in a healthcare system-wide exome sequencing program were retrospectively reviewed. Patients with recurrent stroke within 1 year after index event were compared to those without recurrence. Of 9,348 suspected acute ischemic strokes admitted between 10/2009 and 12/2016, 1,727 (18.5%) enrolled in the exome-sequencing program. Among those, 1,068 patients had exome sequencing completed and were eligible for inclusion. Recurrent stroke within the first year of stroke was observed in 79 patients (7.4%). In multivariable analysis, stroke prior to the index stroke (OR 9.694, 95% CI 5.793-16.224, p ≤ 0.001), pro-coagulant status (OR = 3.563, 95% CI 1.504-8.443, p = 0.004) and the AA genotype of SNP rs1800801 (OR = 2.408, 95% CI 1.079-4.389, p = 0.004) were independently associated with recurrent stroke within the first year. The AA genotype of the MGP SNP rs1800801 is associated with recurrence within the first year after ischemic stroke in North American Caucasians. Study of stroke subtypes and additional populations will be required to determine if incorporation of allelic status at this SNP into current risk scores improves prediction of recurrent ischemic stroke.

Risk Factors for Acute Ischemic Stroke Caused by Anterior Large Vessel Occlusion.

Background and Purpose- Accurate prediction of acute ischemic stroke (AIS) caused by anterior large vessel occlusion (LVO) that is amendable to mechanical thrombectomy remains a challenge. We developed and validated a prediction model for anterior circulation LVO stroke using past medical history elements present on admission and neurological examination. Methods- We retrospectively reviewed AIS patients admitted between 2009 and 2017 to 3 hospitals within a large healthcare system in the United States. Patients with occlusions of the internal carotid artery or M1 or M2 segments of the middle cerebral artery were randomly split into 2/3 derivation and 1/3 validation cohorts for development of an anterior circulation LVO prediction model and score that was further curtailed for potential use in the prehospital setting. Results- A total of 1654 AIS were reviewed, including 248 (15%) with proximal anterior circulation LVO AIS. In the derivation cohort, National Institutes of Health Stroke Scale score at the time of cerebrovascular imaging, current smoking status, type 2 diabetes mellitus, extracranial carotid, and intracranial atherosclerotic stenosis was significantly associated with anterior circulation LVO stroke. The prehospital score was curtailed to National Institutes of Health Stroke Scale score, current smoking status, and type 2 diabetes mellitus. The areas under the curve for the prediction model, prehospital score, and National Institutes of Health Stroke Scale score alone were 0.796, 0.757, and 0.725 for the derivation cohort and 0.770, 0.689, and 0.665 for the validation cohort, respectively. The Youden index J was 0.46 for a score of >6 with 84.7% sensitivity and 62.0% specificity for the prediction model. Conclusions- Previously reported LVO stroke prediction scores focus solely on elements of the neurological examination. In addition to stroke severity, smoking, diabetes mellitus, extracranial carotid, and intracranial atherosclerotic stenosis were associated with anterior circulation LVO AIS. Although atherosclerotic stenosis may not be known until imaging is obtained, smoking and diabetes mellitus history can be readily obtained in the field and represent important elements of the prehospital score supplementing National Institutes of Health Stroke Scale score.

Recovery planning towards doubling wild tiger Panthera tigris numbers: Detailing 18 recovery sites from across the range.

With less than 3200 wild tigers in 2010, the heads of 13 tiger-range countries committed to doubling the global population of wild tigers by 2022. This goal represents the highest level of ambition and commitment required to turn the tide for tigers in the wild. Yet, ensuring efficient and targeted implementation of conservation actions alongside systematic monitoring of progress towards this goal requires that we set site-specific recovery targets and timelines that are ecologically realistic. In this study, we assess the recovery potential of 18 sites identified under WWF's Tigers Alive Initiative. We delineated recovery systems comprising a source, recovery site, and support region, which need to be managed synergistically to meet these targets. By using the best available data on tiger and prey numbers, and adapting existing species recovery frameworks, we show that these sites, which currently support 165 (118-277) tigers, have the potential to harbour 585 (454-739) individuals. This would constitute a 15% increase in the global population and represent over a three-fold increase within these specific sites, on an average. However, it may not be realistic to achieve this target by 2022, since tiger recovery in 15 of these 18 sites is contingent on the initial recovery of prey populations, which is a slow process. We conclude that while sustained conservation efforts can yield significant recoveries, it is critical that we commit our resources to achieving the biologically realistic targets for these sites even if the timelines are extended.

Proteins Encoded by the gerP Operon Are Localized to the Inner Coat in Bacillus cereus Spores and Are Dependent on GerPA and SafA for Assembly.

The germination of Bacillus spores is triggered by certain amino acids and sugar molecules which permeate the outermost layers of the spore to interact with receptor complexes that reside in the inner membrane. Previous studies have shown that mutations in the hexacistronic gerP locus reduce the rate of spore germination, with experimental evidence indicating that the defect stems from reduced permeability of the spore coat to germinant molecules. Here, we use the ellipsoid localization microscopy technique to reveal that all six Bacillus cereus GerP proteins share proximity with cortex-lytic enzymes within the inner coat. We also reveal that the GerPA protein alone can localize in the absence of all other GerP proteins and that it has an essential role for the localization of all other GerP proteins within the spore. Its essential role is also demonstrated to be dependent on SafA, but not CotE, for localization, which is consistent with an inner coat location. GerP-null spores are shown also to have reduced permeability to fluorescently labeled dextran molecules compared to wild-type spores. Overall, the results support the hypothesis that the GerP proteins have a structural role within the spore associated with coat permeability.IMPORTANCE The bacterial spore coat comprises a multilayered proteinaceous structure that influences the distribution, survival, and germination properties of spores in the environment. The results from the current study are significant since they increase our understanding of coat assembly and architecture while adding detail to existing models of germination. We demonstrate also that the ellipsoid localization microscopy (ELM) image analysis technique can be used as a novel tool to provide direct quantitative measurements of spore coat permeability. Progress in all of these areas should ultimately facilitate improved methods of spore control in a range of industrial, health care, and environmental sectors.