Widespread Expansion of Protein Interaction Capabilities by Alternative Splicing.

While alternative splicing is known to diversify the functional characteristics of some genes, the extent to which protein isoforms globally contribute to functional complexity on a proteomic scale remains unknown. To address this systematically, we cloned full-length open reading frames of alternatively spliced transcripts for a large number of human genes and used protein-protein interaction profiling to functionally compare hundreds of protein isoform pairs. The majority of isoform pairs share less than 50% of their interactions. In the global context of interactome network maps, alternative isoforms tend to behave like distinct proteins rather than minor variants of each other. Interaction partners specific to alternative isoforms tend to be expressed in a highly tissue-specific manner and belong to distinct functional modules. Our strategy, applicable to other functional characteristics, reveals a widespread expansion of protein interaction capabilities through alternative splicing and suggests that many alternative "isoforms" are functionally divergent (i.e., "functional alloforms").

A reference map of the human binary protein interactome.

Global insights into cellular organization and genome function require comprehensive understanding of the interactome networks that mediate genotype-phenotype relationships1,2. Here we present a human 'all-by-all' reference interactome map of human binary protein interactions, or 'HuRI'. With approximately 53,000 protein-protein interactions, HuRI has approximately four times as many such interactions as there are high-quality curated interactions from small-scale studies. The integration of HuRI with genome3, transcriptome4 and proteome5 data enables cellular function to be studied within most physiological or pathological cellular contexts. We demonstrate the utility of HuRI in identifying the specific subcellular roles of protein-protein interactions. Inferred tissue-specific networks reveal general principles for the formation of cellular context-specific functions and elucidate potential molecular mechanisms that might underlie tissue-specific phenotypes of Mendelian diseases. HuRI is a systematic proteome-wide reference that links genomic variation to phenotypic outcomes.

The peripheral dopamine 2 receptor antagonist domperidone attenuates ethanol enhancement of dopamine levels in the nucleus accumbens.

BACKGROUND: Dopamine neuron firing in the ventral tegmental area (VTA) and dopamine release in the nucleus accumbens have been implicated in reward learning. Ethanol is known to increase both dopamine neuron firing in the VTA and dopamine levels in the nucleus accumbens. Despite this, some discrepancies exist between the dose of ethanol required to enhance firing in vivo and ex vivo. In the present study we investigated the effects of peripheral dopamine 2 subtype receptor antagonism on ethanol's effects on dopamine neurotransmission. METHODS: Plasma catecholamine levels were assessed following ethanol administration across four different doses of EtOH. Microdialysis and voltammetry were used to assess the effects of domperidone pretreatment on ethanol-mediated increases in dopamine release in the nucleus accumbens. A place conditioning paradigm was used to assess conditioned preference for ethanol and whether domperidone pretreatment altered this preference. Open-field and loss-of-righting reflex paradigms were used to assess the effects of domperidone on ethanol-induced sedation. A rotarod apparatus was used to assess the effects of domperidone on ethanol-induced motor impairment. RESULTS: Domperidone attenuated ethanol's enhancement of mesolimbic dopamine release under non-physiological conditions at intermediate (1.0 and 2.0 g/kg) doses of ethanol. Domperidone also decreased EtOH-induced sedation at 2.0 g/kg. Domperidone did not alter ethanol conditioned place preference nor did it affect ethanol-induced motor impairment. CONCLUSIONS: These results show that peripheral dopamine 2 receptors mediate some of the effects of ethanol on nonphysiological dopamine neurotransmission, although these effects are not related to the rewarding properties of ethanol.

Generic Protocols for the Analytical Validation of Next-Generation Sequencing-Based ctDNA Assays: A Joint Consensus Recommendation of the BloodPAC's Analytical Variables Working Group.

Liquid biopsy, particularly the analysis of circulating tumor DNA (ctDNA), has demonstrated considerable promise for numerous clinical intended uses. Successful validation and commercialization of novel ctDNA tests have the potential to improve the outcomes of patients with cancer. The goal of the Blood Profiling Atlas Consortium (BloodPAC) is to accelerate the development and validation of liquid biopsy assays that will be introduced into the clinic. To accomplish this goal, the BloodPAC conducts research in the following areas: Data Collection and Analysis within the BloodPAC Data Commons; Preanalytical Variables; Analytical Variables; Patient Context Variables; and Reimbursement. In this document, the BloodPAC's Analytical Variables Working Group (AV WG) attempts to define a set of generic analytical validation protocols tailored for ctDNA-based Next-Generation Sequencing (NGS) assays. Analytical validation of ctDNA assays poses several unique challenges that primarily arise from the fact that very few tumor-derived DNA molecules may be present in circulation relative to the amount of nontumor-derived cell-free DNA (cfDNA). These challenges include the exquisite level of sensitivity and specificity needed to detect ctDNA, the potential for false negatives in detecting these rare molecules, and the increased reliance on contrived samples to attain sufficient ctDNA for analytical validation. By addressing these unique challenges, the BloodPAC hopes to expedite sponsors' presubmission discussions with the Food and Drug Administration (FDA) with the protocols presented herein. By sharing best practices with the broader community, this work may also save the time and capacity of FDA reviewers through increased efficiency.

Unexpected consequences of a sudden and massive transposon amplification on rice gene expression.

High-copy-number transposable elements comprise the majority of eukaryotic genomes where they are major contributors to gene and genome evolution. However, it remains unclear how a host genome can survive a rapid burst of hundreds or thousands of insertions because such bursts are exceedingly rare in nature and therefore difficult to observe in real time. In a previous study we reported that in a few rice strains the DNA transposon mPing was increasing its copy number by approximately 40 per plant per generation. Here we exploit the completely sequenced rice genome to determine 1,664 insertion sites using high-throughput sequencing of 24 individual rice plants and assess the impact of insertion on the expression of 710 genes by comparative microarray analysis. We find that the vast majority of transposable element insertions either upregulate or have no detectable effect on gene transcription. This modest impact reflects a surprising avoidance of exon insertions by mPing and a preference for insertion into 5' flanking sequences of genes. Furthermore, we document the generation of new regulatory networks by a subset of mPing insertions that render adjacent genes stress inducible. As such, this study provides evidence for models first proposed previously for the involvement of transposable elements and other repetitive sequences in genome restructuring and gene regulation.

The "fossilized" mitochondrial genome of Liriodendron tulipifera: ancestral gene content and order, ancestral editing sites, and extraordinarily low mutation rate.

BACKGROUND: The mitochondrial genomes of flowering plants vary greatly in size, gene content, gene order, mutation rate and level of RNA editing. However, the narrow phylogenetic breadth of available genomic data has limited our ability to reconstruct these traits in the ancestral flowering plant and, therefore, to infer subsequent patterns of evolution across angiosperms. RESULTS: We sequenced the mitochondrial genome of Liriodendron tulipifera, the first from outside the monocots or eudicots. This 553,721 bp mitochondrial genome has evolved remarkably slowly in virtually all respects, with an extraordinarily low genome-wide silent substitution rate, retention of genes frequently lost in other angiosperm lineages, and conservation of ancestral gene clusters. The mitochondrial protein genes in Liriodendron are the most heavily edited of any angiosperm characterized to date. Most of these sites are also edited in various other lineages, which allowed us to polarize losses of editing sites in other parts of the angiosperm phylogeny. Finally, we added comprehensive gene sequence data for two other magnoliids, Magnolia stellata and the more distantly related Calycanthus floridus, to measure rates of sequence evolution in Liriodendron with greater accuracy. The Magnolia genome has evolved at an even lower rate, revealing a roughly 5,000-fold range of synonymous-site divergence among angiosperms whose mitochondrial gene space has been comprehensively sequenced. CONCLUSIONS: Using Liriodendron as a guide, we estimate that the ancestral flowering plant mitochondrial genome contained 41 protein genes, 14 tRNA genes of mitochondrial origin, as many as 7 tRNA genes of chloroplast origin, >700 sites of RNA editing, and some 14 colinear gene clusters. Many of these gene clusters, genes and RNA editing sites have been variously lost in different lineages over the course of the ensuing ∽200 million years of angiosperm evolution.

Gorgeous mosaic of mitochondrial genes created by horizontal transfer and gene conversion.

The best known outcome of horizontal gene transfer (HGT) is the introduction of novel genes, but other outcomes have been described. When a transferred gene has a homolog in the recipient genome, the native gene may be functionally replaced (and subsequently lost) or partially overwritten by gene conversion with transiently present foreign DNA. Here we report the discovery, in two lineages of plant mitochondrial genes, of novel gene combinations that arose by conversion between coresident native and foreign homologs. These lineages have undergone intricate conversion between native and foreign copies, with conversion occurring repeatedly and differentially over the course of speciation, leading to radiations of mosaic genes involved in respiration and intron splicing. Based on these findings, we develop a model--the duplicative HGT and differential gene conversion model--that integrates HGT and ongoing gene conversion in the context of speciation. Finally, we show that one of these HGT-driven gene-conversional radiations followed two additional types of conversional chimerism, namely, intramitochondrial retroprocessing and interorganellar gene conversion across the 2 billion year divide between mitochondria and chloroplasts. These findings expand our appreciation of HGT and gene conversion as creative evolutionary forces, establish plant mitochondria as a premiere system for studying the evolutionary dynamics of HGT and its genetic reverberations, and recommend careful examination of bacterial and other genomes for similar, likely overlooked phenomena.

Viable viral efficiency of N95 and P100 respirator filters at constant and cyclic flow.

The growing threat of an influenza pandemic presents a unique challenge to healthcare workers, emergency responders, and the civilian population. The Occupational Safety and Health Administration (OSHA) recommends National Institute for Occupational Safety and Health (NIOSH)-approved respirators to provide protection against infectious airborne viruses in various workplace settings. The filtration efficiency of selected NIOSH-approved particulate N95 and P100 filtering facepiece respirators (FFRs) and filter cartridges was investigated against the viable MS2 virus, a non-pathogenic bacteriophage, aerosolized from a liquid suspension. Tests were performed under two cyclic flow conditions (minute volumes of 85 and 135 L/min) and two constant flow rates (85 and 270 L/min). The mean penetrations of viable MS2 through the N95 and P100 FFRs/cartridges were typically less than 2 and 0.03%, respectively, under all flow conditions. All N95 and P100 FFR and cartridge models assessed in this study, therefore, met or exceeded their respective efficiency ratings of 95 and 99.97% against the viable MS2 test aerosol, even under the very high flow conditions. These NIOSH-approved FFRs and particulate respirators equipped with these cartridges can be anticipated to achieve expected levels of protection (consistent with their assigned protection factor) against airborne viral agents, provided that they are properly selected, fitted, worn, and maintained.

The rice miniature inverted repeat transposable element mPing is an effective insertional mutagen in soybean.

Insertional mutagenesis of legume genomes such as soybean (Glycine max) should aid in identifying genes responsible for key traits such as nitrogen fixation and seed quality. The relatively low throughput of soybean transformation necessitates the use of a transposon-tagging strategy where a single transformation event will produce many mutations over a number of generations. However, existing transposon-tagging tools being used in legumes are of limited utility because of restricted transposition (Ac/Ds: soybean) or the requirement for tissue culture activation (Tnt1: Medicago truncatula). A recently discovered transposable element from rice (Oryza sativa), mPing, and the genes required for its mobilization, were transferred to soybean to determine if it will be an improvement over the other available transposon-tagging tools. Stable transformation events in soybean were tested for mPing transposition. Analysis of mPing excision at early and late embryo developmental stages revealed increased excision during late development in most transgenic lines, suggesting that transposition is developmentally regulated. Transgenic lines that produced heritable mPing insertions were identified, with the plants from the highest activity line producing at least one new insertion per generation. Analysis of the mPing insertion sites in the soybean genome revealed that features displayed in rice were retained including transposition to unlinked sites and a preference for insertion within 2.5 kb of a gene. Taken together these findings indicate that mPing has the characteristics necessary for an effective transposon-tagging resource.

Reaerosolization of MS2 bacteriophage from an N95 filtering facepiece respirator by simulated coughing.

The supply of N95 filtering facepiece respirators (FFRs) may not be adequate to match demand during a pandemic outbreak. One possible strategy to maintain supplies in healthcare settings is to extend FFR use for multiple patient encounters; however, contaminated FFRs may serve as a source for the airborne transmission of virus particles. In this study, reaerosolization of virus particles from contaminated FFRs was examined using bacteriophage MS2 as a surrogate for airborne pathogenic viruses. MS2 was applied to FFRs as droplets or droplet nuclei. A simulated cough (370 l min(-1) peak flow) provided reverse airflow through the contaminated FFR. The number and size of the reaerosolized particles were measured using gelatin filters and an Andersen Cascade Impactor (ACI). Two droplet nuclei challenges produced higher percentages of reaerosolized particles (0.21 and 0.08%) than a droplet challenge (<0.0001%). Overall, the ACI-determined size distribution of the reaerosolized particles was larger than the characterized loading virus aerosol. This study demonstrates that only a small percentage of viable MS2 viruses was reaerosolized from FFRs by reverse airflow under the conditions evaluated, suggesting that the risks of exposure due to reaerosolization associated with extended use can be considered negligible for most respiratory viruses. However, risk assessments should be updated as new viruses emerge and better workplace exposure data becomes available.

ProPACC: Protocol for a Trial of Integrated Specialty Palliative Care for Critically Ill Older Adults.

BACKGROUND: Each year, approximately one million older adults die in American intensive care units (ICUs) or survive with significant functional impairment. Inadequate symptom management, surrogates' psychological distress and inappropriate healthcare use are major concerns. Pioneering work by Dr. J. Randall Curtis paved the way for integrating palliative care (PC) specialists to address these needs, but convincing proof of efficacy has not yet been demonstrated. DESIGN: We will conduct a multicenter patient-randomized efficacy trial of integrated specialty PC (SPC) vs. usual care for 500 high-risk ICU patients over age 60 and their surrogate decision-makers from five hospitals in Pennsylvania. INTERVENTION: The intervention will follow recommended best practices for inpatient PC consultation. Patients will receive care from a multidisciplinary SPC team within 24 hours of enrollment that continues until hospital discharge or death. SPC clinicians will meet with patients, families, and the ICU team every weekday. SPC and ICU clinicians will jointly participate in proactive family meetings according to a predefined schedule. Patients in the control arm will receive routine ICU care. OUTCOMES: Our primary outcome is patient-centeredness of care, measured using the modified Patient Perceived Patient-Centeredness of Care scale. Secondary outcomes include surrogates' psychological symptom burden and health resource utilization. Other outcomes include patient survival, as well as interprofessional collaboration. We will also conduct prespecified subgroup analyses using variables such as PC needs, measured by the Needs of Social Nature, Existential Concerns, Symptoms, and Therapeutic Interaction scale. CONCLUSIONS: This trial will provide robust evidence about the impact of integrating SPC with critical care on patient, family, and health system outcomes.

Global population structure of Aspergillus terreus inferred by ISSR typing reveals geographical subclustering.

BACKGROUND: Aspergillus terreus causes invasive aspergillosis (IA) in immunocompromised individuals and can be the leading cause of IA in certain medical centers. We examined a large isolate collection (n = 117) for the presence of cryptic A. terreus species and employed a genome scanning method, Inter-Simple Sequence Repeat (ISSR) PCR to determine A. terreus population structure. RESULTS: Comparative sequence analyses of the calmodulin locus revealed the presence of the recently recognized species A. alabamensis (n = 4) in this collection. Maximum parsimony, Neighbor joining, and Bayesian clustering of the ISSR data from the 113 sequence-confirmed A. terreus isolates demonstrated that one clade was composed exclusively of isolates from Europe and another clade was enriched for isolates from the US. CONCLUSIONS: This study provides evidence of a population structure linked to geographical origin in A. terreus.

Cardiac Amyloidosis Presenting as Biventricular Systolic Heart Failure.

A previously healthy octogenarian presented with new onset heart failure symptoms. Comprehensive multimodality imaging including complete echocardiography with longitudinal strain analysis, cardiac magnetic resonance imaging (cMRI), nuclear medicine pyrophosphate (99-mcTcPYP) scan along with biomarker, monoclonal protein analysis, and fat pad biopsy confirmed diagnosis of transthyretin cardiac amyloidosis.

Right Atrial Appendage Thrombus in Atrial Fibrillation: A Case Report and Review of the Literature.

Atrial fibrillation (Afib) is the most common abnormal heart rhythm in adults and has become a significant public health concern affecting 2% to 3% of the population in Europe and North America. Left atrial appendage (LAA) thrombi is the source of 90% of left-sided cardiac thrombi in patients with Afib, which can cause stroke and other systemic vascular events. Right atrial appendage (RAA) thrombi formation in Afib is much less common but complications include pulmonary embolism or paradoxical migration across patent foramen ovale with risk of systemic embolization. The prevalence and subsequent clinical complications of RAA thrombi formation in Afib patients is not well understood. Management of RAA thrombi should be similar to that of LAA thrombi which includes delaying cardioversion and anticoagulating with warfarin therapy to achieve international normalized ratio of 2 to 3.

Perceptions of Hyperoxemia and Conservative Oxygen Therapy in the Management of Acute Respiratory Failure.

Rationale: Mechanically ventilated patients in the intensive care unit (ICU) are often managed to maximize oxygenation, yet hyperoxemia may be deleterious to some. Little is known about how ICU providers weigh tradeoffs between hypoxemia and hyperoxemia when managing acute respiratory failure. Objectives: To define ICU providers' mental models for managing oxygenation for patients with acute respiratory failure and identify barriers and facilitators to conservative oxygen therapy. Methods: In two large U.S. tertiary care hospitals, we performed semistructured interviews with a purposive sample of ICU nurses, respiratory therapists, and physicians. We assessed perceptions of oxygenation management, hyperoxemia, and conservative oxygen therapies through interviews, which we audio recorded and transcribed verbatim. We analyzed transcripts for representative themes using an iterative thematic-analysis approach. Results: We interviewed 10 nurses, 10 respiratory therapists, 4 fellows, and 5 attending physicians before reaching thematic saturation. Major themes included perceptions of hyperoxemia, attitudes toward conservative oxygen therapy, and aspects of titrated-oxygen-therapy implementation. Many providers did not recognize the term "hyperoxemia," whereas others described a poor understanding; several stated they never encounter hyperoxemia clinically. Concerns about hyperoxemia varied: some providers believed that typical ventilation strategies emphasizing progressive lowering of the fraction of inspired oxygen mitigated worries about excess oxygen administration, whereas others maintained that hyperoxemia is harmful only to patients with chronic lung disease. Almost all interviewees expressed familiarity with lower oxygen saturations in chronic obstructive pulmonary disease. Cited barriers to conservative oxygen therapy included concerns about hypoxemia, particularly among nurses and respiratory therapists; perceptions that hyperoxemia is not harmful; and a lack of clear evidence supporting conservative oxygen therapy. Interviewees suggested that interprofessional education and convincing clinical trial evidence could facilitate uptake of conservative oxygenation. Conclusions: This study describes attitudes toward hyperoxemia and conservative oxygen therapy. These preferences and uncertain benefits and risks of conservative oxygen therapy should be considered during future implementation efforts. Successful oxygen therapy implementation most likely will require 1) improving awareness of hyperoxemia's effects, 2) normalizing lower saturations in patients without chronic lung disease, 3) addressing ingrained beliefs regarding oxygen management and oxygen's safety, and 4) using interprofessional education to obtain buy-in across providers and inform the ICU team.

Magnetic and contrast properties of labeled platelets for magnetomotive optical coherence tomography.

This article introduces a new functional imaging paradigm that uses optical coherence tomography (OCT) to detect rehydrated, lyophilized platelets (RL platelets) that are in the preclinical trial stage and contain superparamagnetic iron oxides (SPIOs) approved by the U.S. Food and Drug Administration. Platelets are highly functional blood cells that detect and adhere to sites of vascular endothelial damage by forming primary hemostatic plugs. By applying magnetic gradient forces, induced nanoscale displacements (magnetomotion) of the SPIO-RL platelets are detected as optical phase shifts in OCT. In this article, we characterize the iron content and magnetic properties of SPIO-RL platelets, construct a model to predict their magnetomotion in a tissue medium, and demonstrate OCT imaging in tissue phantoms and ex vivo pig arteries. Tissue phantoms containing SPIO-RL platelets exhibited >3 dB contrast/noise ratio at ≥1.5 × 10(9) platelets/cm(3). OCT imaging was performed on ex vivo porcine arteries after infusion of SPIO-RL platelets, and specific contrast was obtained on an artery that was surface-damaged (P < 10(-6)). This may enable new technologies for in vivo monitoring of the adherence of SPIO-RL platelets to sites of bleeding and vascular damage, which is broadly applicable for assessing trauma and cardiovascular diseases.

Serratia marcescens Endocarditis with Perivalvular Abscess Presenting as Atrioventricular Block.

Serratia marcescens is an aerobic, Gram-negative bacillus first identified in 1819 (Yeung et al. 2018). S. marcescens infective endocarditis is extremely rare accounting for only 0.14% of all cases (Phadke and Jacob 2016, Hadano et al. 2012, Nikolakopoulos et al. 2019). We present the case of a 33-year-old male with a past medical history of Hodgkin lymphoma, nonischemic cardiomyopathy ejection fraction of 25-30%, severe aortic stenosis, hepatitis C, and active intravenous (IV) drug abuse who was admitted following a motor vehicle accident. Approximately 10 days into his admission, he developed a 39.5 degree Celsius fever, which prompted collection of blood cultures. These cultures were positive (2 out of 2) for S. marcescens for which he was treated with intravenous cefepime. Soon after this diagnosis, patient developed a complete AV block. Given the instability of the patient, he required emergent placement of a temporary pacing wire. Transesophageal echocardiogram was ordered and revealed an aortic root abscess. Given the comorbidities and active IV drug use, conservative management was pursued. Although rare, trends suggest that this pathogen may be on the rise. Further research is needed to better understand how to effectively manage this pathogen.

Strap Performance of N95 Filtering Facepiece Respirators After Multiple Decontamination Cycles.

The Battelle Critical Care Decontamination System™ (CCDS™) decontaminates N95 filtering facepiece respirators (FFRs) using vapor phase hydrogen peroxide (VPHP) for reuse when there is a critical supply shortage. The Battelle CCDS received an Emergency Use Authorization (EUA) from the US Food and Drug Administration (FDA) in March 2020. This research focused on evaluating the mechanical properties of the straps as an indicator of respirator fit. The objective was to characterize the load generated by the straps following up to 20 don/doff and decontamination cycles in Battelle's CCDS. In general, the measured loads at 50 and 100% strains after 20 cycles were similar (±15%) to the as-received controls. Qualitatively, reductions in the load may be associated with loss of elasticity in the straps, potentially reducing the ability to obtain a proper fit. However, small changes in strap elasticity may not affect the ability to obtain a proper fit given the potential for variation in strap length and positioning on the head. Regardless, prior to reusing a N95 respirator, it is important to complete a visual inspection to ensure it is not damaged, malformed, or soiled. If so, it is recommended to discard the respirator and use a different one. Similarly, the respirator should be discarded if the wearer cannot obtain a proper fit during the user seal check.

N95 and p100 respirator filter efficiency under high constant and cyclic flow.

This study investigated the effect of high flow conditions on aerosol penetration and the relationship between penetration at constant and cyclic flow conditions. National Institute for Occupational Safety and Health (NIOSH)-approved N95 and P100 filtering facepiece respirators and cartridges were challenged with inert solid and oil aerosols. A combination of monodisperse aerosol and size-specific aerosol measurement equipment allowed count-based penetration measurement of particles with nominal diameters ranging from 0.02 to 2.9 microm. Three constant flow conditions (85, 270, and 360 L/min) were selected to match the minute, inhalation mean, and inhalation peak flows of the four cyclic flow conditions (40, 85, 115, and 135 L/min) tested. As expected, penetration was found to increase under increased constant and cyclic flow conditions. The most penetrating particle size (MPPS) generally ranged from 0.05 to 0.2 microm for P100 filters and was approximately 0.05 microm for N95 filters. Although penetration increased at the high flow conditions, the MPPS was relatively unaffected by flow. Of the constant flows tested, the flows equivalent to cyclic inhalation mean and peak flows best approximated the penetration measurements of the corresponding cyclic flows.

Endocarditis caused by Stenotrophomonas maltophilia-A rare presentation of an emerging opportunistic pathogen.

First isolated in 1943, Stenotrophomonas maltophilia (S. maltophilia) has historically been of little significance as it was considered a pathogen of low virulence noted to rarely infect immunocompromised hosts. However, over the last 30 years the prevalence of infection caused by the organism has increased significantly. Bacterial endocarditis from S. maltophilia remains exceedingly rare with only a small number of reported cases in the literature. This case involves a 27 year old male with sickle cell anemia with an indwelling right subclavian port who presented to the emergency department with myalgias, fever, and chills. His initial blood cultures grew Gram negative rods later identified as S. maltophilia. Transthoracic echocardiogram showed a mass in the right atrium. Transesophageal echocardiogram revealed a large C-shaped mass with attachment to the tricuspid annulus, mitral valve wall, and port tip in right atrium. The patient underwent sternotomy with removal of the vegetation to prevent embolization. He was treated with intravenous ciprofloxacin and oral trimethoprim/sulfamethoxazole to complete a full 6 weeks of therapy, making a full recovery. This report will further explore the unique presentation of this pathogen along with its epidemiology, resistance mechanisms, risk factors for infection, diagnosis, and appropriate antimicrobial treatment.