Synonymous codon usage regulates translation initiation.

Nonoptimal synonymous codons repress gene expression, but the underlying mechanisms are poorly understood. We and others have previously shown that nonoptimal codons slow translation elongation speeds and thereby trigger messenger RNA (mRNA) degradation. Nevertheless, transcript levels are often insufficient to explain protein levels, suggesting additional mechanisms by which codon usage regulates gene expression. Using reporters in human and Drosophila cells, we find that transcript levels account for less than half of the variation in protein abundance due to codon usage. This discrepancy is explained by translational differences whereby nonoptimal codons repress translation initiation. Nonoptimal transcripts are also less bound by the translation initiation factors eIF4E and eIF4G1, providing a mechanistic explanation for their reduced initiation rates. Importantly, translational repression can occur without mRNA decay and deadenylation, and it does not depend on the known nonoptimality sensor, CNOT3. Our results reveal a potent mechanism of regulation by codon usage where nonoptimal codons repress further rounds of translation.

A multiplexed, paired-pooled droplet digital PCR assay for detection of SARS-CoV-2 in saliva.

In response to the SARS-CoV-2 pandemic, we developed a multiplexed, paired-pool droplet digital PCR (MP4) screening assay. Key features of our assay are the use of minimally processed saliva, 8-sample paired pools, and reverse-transcription droplet digital PCR (RT-ddPCR) targeting the SARS-CoV-2 nucleocapsid gene. The limit of detection was determined to be 2 and 12 copies per µl for individual and pooled samples, respectively. Using the MP4 assay, we routinely processed over 1,000 samples a day with a 24-h turnaround time and over the course of 17 months, screened over 250,000 saliva samples. Modeling studies showed that the efficiency of 8-sample pools was reduced with increased viral prevalence and that this could be mitigated by using 4-sample pools. We also present a strategy for, and modeling data supporting, the creation of a third paired pool as an additional strategy to employ under high viral prevalence.

Imaging translational control by Argonaute with single-molecule resolution in live cells.

A major challenge to our understanding of translational control has been deconvolving the individual impact specific regulatory factors have on the complex dynamics of mRNA translation. MicroRNAs (miRNAs), for example, guide Argonaute and associated proteins to target mRNAs, where they direct gene silencing in multiple ways that are not well understood. To better deconvolve these dynamics, we have developed technology to directly visualize and quantify the impact of human Argonaute2 (Ago2) on the translation and subcellular localization of individual reporter mRNAs in living cells. We show that our combined translation and Ago2 tethering sensor reflects endogenous miRNA-mediated gene silencing. Using the sensor, we find that Ago2 association leads to progressive silencing of translation at individual mRNA. Silencing was occasionally interrupted by brief bursts of translational activity and took 3-4 times longer than a single round of translation, consistent with a gradual increase in the inhibition of translation initiation. At later time points, Ago2-tethered mRNAs cluster and coalesce with P-bodies, where a translationally silent state is maintained. These results provide a framework for exploring miRNA-mediated gene regulation in live cells at the single-molecule level. Furthermore, our tethering-based, single-molecule reporter system will likely have wide-ranging application in studying RNA-protein interactions.

Bead Loading Proteins and Nucleic Acids into Adherent Human Cells.

Many live-cell imaging experiments use exogenous particles (e.g., peptides, antibodies, beads) to label or function within cells. However, introducing proteins into a cell across its membrane is difficult. The limited selection of current methods struggles with low efficiency, requires expensive and technically demanding equipment, or functions within narrow parameters. Here, we describe a relatively simple and cost-effective technique for loading DNA, RNA, and proteins into live human cells. Bead loading induces a temporary mechanical disruption to the cell membrane, allowing macromolecules to enter adherent, live mammalian cells. At less than 0.01 USD per experiment, bead loading is the least expensive cell loading method available. Moreover, bead loading does not substantially stress cells or impact their viability or proliferation. This manuscript describes the steps of the bead loading procedure, adaptations, variations, and technical limitations. This methodology is especially suited for live-cell imaging but provides a practical solution for other applications requiring the introduction of proteins, beads, RNA, or plasmids into living, adherent mammalian cells.

Algorithms for clinical assessment of the cervical spine in patients with severe trauma: a mixed-method analyzis / Algoritmos de avaliação clínica da coluna cervical em pacientes com traumatismo grave: uma análise mista / Algoritmos de evaluación clínica de la columna cervical en pacientes con traumatismo grave: un análisis mixto

ABSTRACT Objective: Cervical trauma is an important cause of morbidity and mortality, affecting 2% of patients admitted to emergency units. Therefore, this study aims to compare the use of two clinical cervical spine evaluation algorithms, the Canadian C-Spine Rule (CCR) and the National Emergency X-radiography Utilization Study (NEXUS). Methods: A descriptive study of the use of the two algorithms by medical residents in the initial assessment of severely traumatized patients admitted to the regional emergency unit was conducted. The evaluation of the indication for imaging tests and the positive predictive value of the algorithms were the parameters analyzed. Finally, the residents answered a questionnaire evaluating the applicability, degree of confidence and advantages of both flowcharts. Results: There was no significant difference between the number of indications for imaging or their predictive values. In the analysis of the questionnaires, the CCR proved to be more reliable and the NEXUS more applicable, and the positive and negative points of applying each of them were highlighted. Conclusion: It is concluded that the two methods are similar in detecting injuries and optimizing the use of imaging exams, being equally indicated to evaluate cervical trauma. However, the technical specifics of each must be taken into account when deciding which to use. Level of evidence IV; Descriptive Study.

RESUMO Objetivo: O trauma cervical é uma importante causa de morbidade e mortalidade, com acometimento de 2% dos pacientes admitidos nas unidades de emergência. Assim sendo, a pesquisa visa comparar a utilização de dois algoritmos clínicos de avaliação da coluna cervical: Canadian C-Spine Rule (CCR) e National Emergency X-radiography Utilization Study (NEXUS). Métodos: Foi realizado um estudo descritivo da utilização dos dois algoritmos por médicos residentes na avaliação inicial de pacientes traumatizados graves admitidos na unidade de emergência regional. A avaliação da indicação de exames de imagem e do valor preditivo positivo dos algoritmos foram os parâmetros analisados. Por fim, os residentes responderam a um questionário de avaliação da aplicabilidade, grau de confiança e vantagens de ambos os fluxogramas. Resultados: Não houve diferença significativa entre os números de indicação para imagem nem dos valores preditivos. Na análise do questionário, o CCR mostrou-se mais confiável e o NEXUS foi mais aplicável, sendo destacados os pontos positivos e negativos da aplicação de cada um deles. Conclusões: Conclui-se que houve semelhança na detecção de lesões e otimização da utilização de exames de imagem entre os dois métodos, sendo igualmente indicados para avaliação de traumatismo cervical, contudo cada um tem especificidades técnicas que devem ser levadas em conta no momento da escolha. Nível de evidência IV; Estudo descritivo.

RESUMEN Objetivo: El trauma cervical es una importante causa de morbilidad y mortalidad, con acometimiento de 2% de los pacientes admitidos en las unidades de emergencia. Siendo así, la investigación tiene como objetivo comparar el uso de dos algoritmos clínicos de evaluación de la columna cervical: Canadian C-Spine Rule (CCR) y National Emergency X-radiography Utilization Study (NEXUS). Métodos: Fue realizado un estudio descriptivo del uso de los dos algoritmos por médicos residentes en la evaluación inicial de los pacientes traumatizados graves admitidos en la unidad de emergencia regional. La evaluación de la indicación de exámenes de imagen y del valor predictivo positivo de los algoritmos fueron los parámetros analizados. Finalmente, los residentes respondieron un cuestionario de evaluación de la aplicabilidad, grado de confianza y ventajas de ambos diagramas de flujo. Resultados: No hubo diferencia significativa entre los números de indicación para imagen ni de los valores predictivos. En el análisis del cuestionario, el CCR se mostró más confiable y el NEXUS fue más aplicable, siendo destacados los puntos positivos y negativos de la aplicación de cada uno de ellos. Conclusiones: Se concluye que hubo semejanza en la detección de lesiones y optimización del uso de exámenes de imagen entre los dos métodos, siendo igualmente indicados para la evaluación de traumatismo cervical, aunque cada uno tiene especificidades técnicas que deben ser llevadas en cuenta en el momento de elegir. Nivel de evidencia IV; Estudio descriptivo.

Nonoperative treatment of a blunt adrenal gland trauma with blush: A case report.

Adrenal gland trauma is a rare and scarcely reported injury due to its retroperitoneal position and relationship with adjacent tissues. We report a male patient with a history of a thoracoabdominal blunt trauma with adrenal injury as an isolated abdominal viscera. He was hemodynamically stable at admission, with a blush within his adrenal hematoma. The patient was treated nonoperatively and subsequently discharged after 15 days. The available literature reports advantages of a nonoperative approach compared to surgery, which is necessary in only 1% of cases that are predominantly polytrauma patients with multiple intra-abdominal injuries. Therefore, a nonoperative treatment is recommended for patients with an isolated adrenal gland injury who are hemodynamically stable during hospital stay.

Lighting up single-mRNA translation dynamics in living cells.

Over the past five years, technological advances have made it possible to image the translation of single mRNA in the natural context of living cells. With these advances, researchers are beginning to shed light on when, where, and to what degree mRNA are translated with single-molecule precision. These works provide insight into the heterogeneity of translation amongst single transcripts, behavior that is averaged out in complementary bulk assays. In this review, we discuss the rapidly maturing field of live-cell, single-mRNA imaging of translation, beginning with a brief overview of recent technological advances. The remainder of the review focuses on the new biological insights gained from these technologies. We conclude with a discussion of the future of this technology.

Synthesis, Structural and Physicochemical Properties of Water-Soluble Mixed-Ligand Diruthenium Complexes Containing Anilinopyridinate Bridging Ligands.

A series of water-soluble Ru25+ complexes of the type Ru2(O2CCH3)3(L)Cl where L = 2,3,4,5,6-F5ap, 2,4,6-F3ap, 2-Fap, ap, 2-Meap, 2,6-Me2ap, or 2,4,6-Me3ap, where ap is the anilinopyridinate anion, have been characterized as to their structural and physicochemical properties in H2O and DMSO. Five of the newly synthesized complexes were structurally characterized, and the Ru-Cl bond lengths range from 2.477 to 2.544 Å while the Ru-Ru bond lengths range from 2.2838 to 2.2935 Å. The UV-vis spectra of each compound are characterized by three absorption bands in both H2O and DMSO, the intensity and position of which vary with both the type of bridging ligand and the solvent. The seven examined Ru25+ complexes exist as 1:1 electrolytes in water, and each undergoes a reversible one-electron reduction assigned to Ru25+/Ru24+ in both investigated solvents. A second irreversible reduction attributed to Ru24+/Ru23+ is also observed for each compound at more negative potentials in DMSO. A linear free energy relationship exists between the sum of the Hammett substituent constants (Σσ) on the ap-type bridging ligand and the wavenumber of an absorption band for the Ru25+ complexes. A linear relationship is also seen between Σσ and measured E1/2 values for the Ru25+/Ru24+ process in water containing 0.1 M KCl, but little to no effect is seen between the specific bridging ligand and the structural features of the investigated compounds.

Reflejo trigémino cardíaco durante artroscopia de la articulación temporomandibular. Reporte de caso clínico / Trigeminocardiac reflex during arthroscopy of the temporomandibular joint. Clinical case report

Introducción: el reflejo trigémino cardíaco es una respuesta fisiológica parasimpática repentina, que ocasiona alteraciones cardiovasculares importantes durante la esti-mulación nerviosa en el trayecto del V par craneal, generalmente ocurre al realizar procedimientos quirúrgicos en cirugía oral y maxilofacial, neurocirugía, oftalmología y dermatología. La artroscopia de la articulación temporomandibular ha sido tradicional-mente considerada un procedimiento quirúrgico seguro, mínimamente invasivo, aun así, esta técnica no está exenta de complicaciones neuro y cardiovasculares. Objetivo:presentar un caso clínico que durante una artroscopia de la articulación temporo-mandibular en la fase de instrumentación del espacio articular superior, y que, bajo monitoreo continuo del anestesiólogo, reportó una bradicardia súbita. Conclusión: el diagnóstico intraoperatorio de reflejo trigémino cardíaco, fue descrito por el servicio de anestesiología recibiendo un tratamiento farmacológico temprano para esta condi-ción, lo que permitió obtener una adecuada evolución trans y postoperatoria

Background: Trigeminocardiac reflex is a sudden parasympathetic physiological response causing significant cardiovascular disturbances during nerve stimulation in the path of the fifth cranial nerve, generally during surgical procedures in oral and maxillofacial surgery, neurosurgery, ophthalmology, and dermatology. Arthroscopy of the temporomandibular joint has traditionally been considered a safe, minimally invasive surgical procedure, yet this technique is not without neuro and cardiovascular complications. Objective: To present a clinical case that during an arthroscopy of the temporomandibular joint in the instrumentation phase of the superior joint space, and under continuous monitoring by the anesthetist, report sudden bradycardia Conclusion: The intraoperative diagnosis of trigeminocardiac reflex was described by the anesthesiology service, receiving early pharmacological treatment of this condition, allowing an adequate trans and postoperative evolution.

Neurophysiological Muscle Activation Scheme for Controlling Vocal Fold Models.

A physiologically-based scheme that incorporates inherent neurological fluctuations in the activation of intrinsic laryngeal muscles into a lumped-element vocal fold model is proposed. Herein, muscles are activated through a combination of neural firing rate and recruitment of additional motor units, both of which have stochastic components. The mathematical framework and underlying physiological assumptions are described, and the effects of the fluctuations are tested via a parametric analysis using a body-cover model of the vocal folds for steady-state sustained vowels. The inherent muscle activation fluctuations have a bandwidth that varies with the firing rate, yielding both low and high-frequency components. When applying the proposed fluctuation scheme to the voice production model, changes in the dynamics of the system can be observed, ranging from fluctuations in the fundamental frequency to unstable behavior near bifurcation regions. The resulting coefficient of variation of the model parameters is not uniform with muscle activation. The stochastic components of muscle activation influence both the fine structure variability and the ability to achieve a target value for pitch control. These components can have a significant impact on the vocal fold parameters, as well as the outputs of the voice production model. Good agreement was found when contrasting the proposed scheme with prior experimental studies accounting for variability in vocal fold posturing and spectral characteristics of the muscle activation signal. The proposed scheme constitutes a novel and physiologically-based approach for controlling lumped-element models for normal voice production and can be extended to explore neuropathological conditions.

Estimating Vocal Fold Contact Pressure from Raw Laryngeal High-Speed Videoendoscopy Using a Hertz Contact Model.

The development of trauma-induced lesions of the vocal folds (VFs) has been linked to a high collision pressure on the VF surface. However, there are no direct methods for the clinical assessment of VF collision, thus limiting the objective assessment of these disorders. In this study, we develop a video processing technique to directly quantify the mechanical impact of the VFs using solely laryngeal kinematic data. The technique is based on an edge tracking framework that estimates the kinematic sequence of each VF edge with a Kalman filter approach and a Hertzian impact model to predict the contact force during the collision. The proposed formulation overcomes several limitations of prior efforts since it uses a more relevant VF contact geometry, it does not require calibrated physical dimensions, it is normalized by the tissue properties, and it applies a correction factor for using a superior view only. The proposed approach is validated against numerical models, silicone vocal fold models, and prior studies. A case study with high-speed videoendoscopy recordings provides initial insights between the sound pressure level and contact pressure. Thus, the proposed method has a high potential in clinical practice and could also be adapted to operate with laryngeal stroboscopic systems.

Modeling the Pathophysiology of Phonotraumatic Vocal Hyperfunction With a Triangular Glottal Model of the Vocal Folds.

Purpose: Our goal was to test prevailing assumptions about the underlying biomechanical and aeroacoustic mechanisms associated with phonotraumatic lesions of the vocal folds using a numerical lumped-element model of voice production. Method: A numerical model with a triangular glottis, posterior glottal opening, and arytenoid posturing is proposed. Normal voice is altered by introducing various prephonatory configurations. Potential compensatory mechanisms (increased subglottal pressure, muscle activation, and supraglottal constriction) are adjusted to restore an acoustic target output through a control loop that mimics a simplified version of auditory feedback. Results: The degree of incomplete glottal closure in both the membranous and posterior portions of the folds consistently leads to a reduction in sound pressure level, fundamental frequency, harmonic richness, and harmonics-to-noise ratio. The compensatory mechanisms lead to significantly increased vocal-fold collision forces, maximum flow-declination rate, and amplitude of unsteady flow, without significantly altering the acoustic output. Conclusion: Modeling provided potentially important insights into the pathophysiology of phonotraumatic vocal hyperfunction by demonstrating that compensatory mechanisms can counteract deterioration in the voice acoustic signal due to incomplete glottal closure, but this also leads to high vocal-fold collision forces (reflected in aerodynamic measures), which significantly increases the risk of developing phonotrauma.

Non-stationary Bayesian estimation of parameters from a body cover model of the vocal folds.

The evolution of reduced-order vocal fold models into clinically useful tools for subject-specific diagnosis and treatment hinges upon successfully and accurately representing an individual patient in the modeling framework. This, in turn, requires inference of model parameters from clinical measurements in order to tune a model to the given individual. Bayesian analysis is a powerful tool for estimating model parameter probabilities based upon a set of observed data. In this work, a Bayesian particle filter sampling technique capable of estimating time-varying model parameters, as occur in complex vocal gestures, is introduced. The technique is compared with time-invariant Bayesian estimation and least squares methods for determining both stationary and non-stationary parameters. The current technique accurately estimates the time-varying unknown model parameter and maintains tight credibility bounds. The credibility bounds are particularly relevant from a clinical perspective, as they provide insight into the confidence a clinician should have in the model predictions.

Modeling the effects of a posterior glottal opening on vocal fold dynamics with implications for vocal hyperfunction.

Despite the frequent observation of a persistent opening in the posterior cartilaginous glottis in normal and pathological phonation, its influence on the self-sustained oscillations of the vocal folds is not well understood. The effects of a posterior gap on the vocal fold tissue dynamics and resulting acoustics were numerically investigated using a specially designed flow solver and a reduced-order model of human phonation. The inclusion of posterior gap areas of 0.03-0.1 cm(2) reduced the energy transfer from the fluid to the vocal folds by more than 42%-80% and the radiated sound pressure level by 6-14 dB, respectively. The model was used to simulate vocal hyperfucntion, i.e., patterns of vocal misuse/abuse associated with many of the most common voice disorders. In this first approximation, vocal hyperfunction was modeled by introducing a compensatory increase in lung air pressure to regain the vocal loudness level that was produced prior to introducing a large glottal gap. This resulted in a significant increase in maximum flow declination rate and amplitude of unsteady flow, thereby mimicking clinical studies. The amplitude of unsteady flow was found to be linearly correlated with collision forces, thus being an indicative measure of vocal hyperfunction.

Sexual healthcare preferences among gay and bisexual men: a qualitative study in San Francisco, California.

BACKGROUND: Research on gay and other men who have sex with men's (G/MSM) preferences for sexual healthcare services focuses largely on HIV testing and to some extent on sexually transmitted infections (STI). This research illustrates the frequency and location of where G/MSM interface with the healthcare system, but it does not speak to why men seek care in those locations. As HIV and STI prevention strategies evolve, evidence about G/MSM's motivations and decision-making can inform future plans to optimize models of HIV/STI prevention and primary care. METHODS: We conducted a phenomenological study of gay men's sexual health seeking experiences, which included 32 in-depth interviews with gay and bisexual men. Interviews were transcribed verbatim and entered into Atlas.ti. We conducted a Framework Analysis. FINDINGS: We identified a continuum of sexual healthcare seeking practices and their associated drivers. Men differed in their preferences for separating sexual healthcare from other forms of healthcare ("fragmentation") versus combining all care into one location ("consolidation"). Fragmentation drivers included: fear of being monitored by insurance companies, a desire to seek non-judgmental providers with expertise in sexual health, a desire for rapid HIV testing, perceiving sexual health services as more convenient than primary care services, and a lack of healthcare coverage. Consolidation drivers included: a comfortable and trusting relationship with a provider, a desire for one provider to oversee overall health and those with access to public or private health insurance. CONCLUSIONS: Men in this study were likely to separate sexual healthcare from primary care. Based on this finding, we recommend placing new combination HIV/STI prevention interventions within sexual health clinics. Furthermore, given the evolution of the financing and delivery of healthcare services and in HIV prevention, policymakers and clinicians should consider including more primary care services within sexual healthcare settings.

A loss of moral experience: understanding HIV-related stigma in the New York City House and Ball Community.

OBJECTIVES: I incorporated qualitative methods to explore how HIV-related stigma functions in New York City's House and Ball Community (HBC). METHODS: From January through March 2009, I conducted 20 in-depth 1-on-1 interviews with a diverse sample of New York City HBC members. Interviews addressed perceptions of HIV-related stigma, the treatment of HIV-positive members in the community, and the potential impact of HIV-related stigma on risk behaviors. RESULTS: HIV-related stigma contributes to a loss of moral experience for HBC members. Moral experience (i.e., threats to what really matters in a community) disrupts established social connections and hinders the attainment of "ball status" (i.e., amassing social recognition) in the local world of these individuals. CONCLUSIONS: My recommendations address HIV-related stigma in the New York City HBC from the vantage of moral experience and highlight the need for longitudinal studies of individual house members and for the implementation of stigma-focused interventions in the community that utilize the unique ball status hierarchy and HBC network to influence social norms surrounding the treatment of HIV-positive community members.

Community member perspectives from transgender women and men who have sex with men on pre-exposure prophylaxis as an HIV prevention strategy: implications for implementation.

BACKGROUND: An international randomized clinical trial (RCT) on pre-exposure prophylaxis (PrEP) as an human immunodeficiency virus (HIV)-prevention intervention found that taken on a daily basis, PrEP was safe and effective among men who have sex with men (MSM) and male-to-female transgender women. Within the context of the HIV epidemic in the United States (US), MSM and transgender women are the most appropriate groups to target for PrEP implementation at the population level; however, their perspectives on evidenced-based biomedical research and the results of this large trial remain virtually unknown. In this study, we examined the acceptability of individual daily use of PrEP and assessed potential barriers to community uptake. METHODS: We conducted semi-structured interviews with an ethnoracially diverse sample of thirty HIV-negative and unknown status MSM (n = 24) and transgender women (n = 6) in three California metropolitan areas. Given the burden of disease among ethnoracial minorities in the US, we purposefully oversampled for these groups. Thematic coding and analysis of data was conducted utilizing an approach rooted in grounded theory. RESULTS: While participants expressed general interest in PrEP availability, results demonstrate: a lack of community awareness and confusion about PrEP; reservations about PrEP utilization, even when informed of efficacious RCT results; and concerns regarding equity and the manner in which a PrEP intervention could be packaged and marketed in their communities. CONCLUSIONS: In order to effectively reduce HIV health disparities at the population level, PrEP implementation must take into account the uptake concerns of those groups who would actually access and use this biomedical intervention as a prevention strategy. Recommendations addressing these concerns are provided.

A qualitative study of provider thoughts on implementing pre-exposure prophylaxis (PrEP) in clinical settings to prevent HIV infection.

BACKGROUND: A recent clinical trial demonstrated that a daily dose tenofovir disoproxil fumarate and emtricitabrine (TDF-FTC) can reduce HIV acquisition among men who have sex with men (MSM) and transgender (TG) women by 44%, and up to 90% if taken daily. We explored how medical and service providers understand research results and plan to develop clinical protocols to prescribe, support and monitor adherence for patients on PrEP in the United States. METHODS: Using referrals from our community collaborators and snowball sampling, we recruited 22 healthcare providers in San Francisco, Oakland, and Los Angeles for in-depth interviews from May-December 2011. The providers included primary care physicians seeing high numbers of MSM and TG women, HIV specialists, community health clinic providers, and public health officials. We analyzed interviews thematically to produce recommendations for setting policy around implementing PrEP. Interview topics included: assessing clinician impressions of PrEP and CDC guidance, considerations of cost, office capacity, dosing schedules, and following patients over time. RESULTS: Little or no demand for PrEP from patients was reported at the time of the interviews. Providers did not agree on the most appropriate patients for PrEP and believed that current models of care, which do not involve routine frequent office visits, were not well suited for prescribing PrEP. Providers detailed the need to build capacity and were concerned about monitoring side effects and adherence. PrEP was seen as potentially having impact on the epidemic but providers also noted that community education campaigns needed to be tailored to effectively reach specific vulnerable populations. CONCLUSIONS: While PrEP may be a novel and clinically compelling prevention intervention for MSM and TG women, it raises a number of important implementation challenges that would need to be addressed. Nonetheless, most providers expressed optimism that they eventually could prescribe and monitor PrEP in their practice.

Community associated methicillin resistant Staphylococcus aureus among New York City men who have sex with men: qualitative research findings and implications for public health practice.

Academic literature has recorded increased microbial resistance in the United States and recent news media has adversely portrayed men who have sex with men (MSM) at increased risk for community associated methicillin resistant Staphylococcus aureus (CA-MRSA) transmission. CA-MRSA is a specific type of bacteria resistant to certain antibiotics, which limits treatment options for those needing clinical care. Infection can manifest as painful abscesses and can cause severe illness. With increased CA-MRSA infections overall, and attention given to MSM populations regarding CA-MRSA, as well as the fact that limited data on sociocultural factors that may facilitate transmission, we undertook a qualitative study to explore contextual influences that may fuel infection among MSM in New York City so that public health professionals can better recognize, and respond appropriately to, potential future outbreaks. In-depth interviews were used to qualitatively investigate perceptions and beliefs regarding transmission, as well as community understandings of treatment options. Participants included thirteen MSM who reported a previous CA-MRSA infection and nine community practitioners. A thematic content analysis of these interviews was conducted and data suggests that behaviors and exposures associated with transmission of CA-MRSA are common in certain MSM networks. Specifically, sociocultural influences and methamphetamine use activities were found to contribute to CA-MRSA transmission. We underscore the role of public health and health services practitioners in providing appropriate CA-MRSA awareness and education to MSM populations.