Th2 cytokine signaling through IL-4Rα increases eotaxin-3 secretion and tension in human esophageal smooth muscle.

In esophageal epithelial cells in eosinophilic esophagitis (EoE), Th2 cytokines (IL-4, IL-13) signal through IL-4Rα, activating JAK to increase eotaxin-3 secretion, which draws eosinophils into the mucosa. We explored whether Th2 cytokines also might stimulate eotaxin-3 secretion and increase tension in esophageal smooth muscle (ESM), which might impair esophageal distensibility, and whether those events could be blocked by proton pump inhibitors (PPIs) or agents that disrupt IL-4Rα signaling. We established human ESM cell cultures from organ donors, characterizing Th2 cytokine receptor and P-type ATPase expression by qPCR. We measured Th2 cytokine-stimulated eotaxin-3 secretion by enzyme-linked immunosorbent assay (ELISA) and ESM cell tension by gel contraction assay, before and after treatment with omeprazole, ruxolitinib (JAK inhibitor), or IL-4Rα blocking antibody. CPI-17 (inhibitor of a muscle-relaxing enzyme) effects were studied with CPI-17 knockdown by siRNA or CPI-17 phospho(T38A)-mutant overexpression. ESM cells expressed IL-4Rα and IL-13Rα1 but only minimal H+-K+-ATPase mRNA. Th2 cytokines increased ESM eotaxin-3 secretion and tension, effects blocked by ruxolitinib and IL-4Rα blocking antibody but not consistently blocked by omeprazole. IL-13 increased ESM tension by increasing CPI-17 expression and phosphorylation, effects blocked by CPI-17 knockdown. Blocking IL-4Rα decreased IL-13-stimulated eotaxin-3 secretion, CPI-17 expression, and tension in ESM. Th2 cytokines increase ESM eotaxin-3 secretion and tension via IL-4Rα signaling that activates CPI-17. Omeprazole does not reliably inhibit this process, but IL-4Rα blocking antibody does. This suggests that ESM eosinophilia and impaired esophageal distensibility might persist despite elimination of mucosal eosinophils by PPIs, and IL-4Rα blocking agents might be especially useful in this circumstance.NEW & NOTEWORTHY We have found that Th2 cytokines increase eotaxin-3 secretion and tension in esophageal smooth muscle (ESM) cells via IL-4Rα signaling. Unlike esophageal epithelial cells, ESM cells do not express H+-K+-ATPase, and omeprazole does not inhibit their cytokine-stimulated eotaxin-3 secretion or tension. An IL-4Rα blocking antibody reduces both eotaxin-3 secretion and tension induced by Th2 cytokines in ESM cells, suggesting that an agent such as dupilumab might be preferred for patients with EoE with esophageal muscle involvement.

#DebunkingDesire: Sexual Science, Social Media, and Strategy in the Pursuit of Knowledge Dissemination.

Approximately 1 in 3 women experience low sexual desire. Despite this being a common concern, many women never seek professional help for their difficulties and will instead turn to online resources for information. We sought to address this need for digitally-accessible, evidence-based information on low sexual desire by creating a social media Knowledge Translation (KT) campaign called #DebunkingDesire. Our team led a 10 month social media campaign where our primary outcomes for the campaign were impressions, reach, and engagement. We generated over 300,000 social media impressions; appeared on 11 different podcasts that were listened to/downloaded 154,700 times; hosted and participated in eight online events; and attracted website users from 110 different countries. Over the course of the campaign we compiled lessons learned on what worked for disseminating our key messages and the importance of creating community for this population. These findings point to the utility of using social media as part of KT campaigns in sexual health, and to the importance of collaborating with patient partners and considering social media ads and podcasts to meet reach goals.

Effects of management outweigh effects of plant diversity on restored animal communities in tallgrass prairies.

A primary goal of ecological restoration is to increase biodiversity in degraded ecosystems. However, the success of restoration ecology is often assessed by measuring the response of a single functional group or trophic level to restoration, without considering how restoration affects multitrophic interactions that shape biodiversity. An ecosystem-wide approach to restoration is therefore necessary to understand whether animal responses to restoration, such as changes in biodiversity, are facilitated by changes in plant communities (plant-driven effects) or disturbance and succession resulting from restoration activities (management-driven effects). Furthermore, most restoration ecology studies focus on how restoration alters taxonomic diversity, while less attention is paid to the response of functional and phylogenetic diversity in restored ecosystems. Here, we compared the strength of plant-driven and management-driven effects of restoration on four animal communities (ground beetles, dung beetles, snakes, and small mammals) in a chronosequence of restored tallgrass prairie, where sites varied in management history (prescribed fire and bison reintroduction). Our analyses indicate that management-driven effects on animal communities were six-times stronger than effects mediated through changes in plant biodiversity. Additionally, we demonstrate that restoration can simultaneously have positive and negative effects on biodiversity through different pathways, which may help reconcile variation in restoration outcomes. Furthermore, animal taxonomic and phylogenetic diversity responded differently to restoration, suggesting that restoration plans might benefit from considering multiple dimensions of animal biodiversity. We conclude that metrics of plant diversity alone may not be adequate to assess the success of restoration in reassembling functional ecosystems.

The effects of scaling and root planing plus home oral hygiene maintenance in Stage I/II periodontitis population: A 24-week randomized clinical trial.

OBJECTIVES: To compare the effects of powered and manual toothbrushing following scaling and root planing on bleeding on probing and other clinical indicators of periodontitis. MATERIALS AND METHODS: This was a randomized, examiner-blind, parallel-design, 24-week clinical study. Eligible subjects were 18-75 years of age with Stage I or II periodontitis. All subjects received scaling and root planing (SRP) within 28 days of enrollment. Thereafter, subjects were randomized to twice daily at-home use of either a powered toothbrush (PTB) or a manual toothbrush (MTB). Randomization was balanced for gender and periodontitis stage. No other oral hygiene aids were permitted. Subjects were evaluated every 4 weeks for the following measures: bleeding on probing (BOP), surface plaque (MPI), probing pocket depth (PPD) and clinical attachment level until Week 24. RESULTS: Of 328 randomized subjects, 299 subjects completed the study. For BOP at Week 24, the Least Squares (LS) Mean, standard error (SE) reduction from baseline was 0.24 (0.01) for the PTB group and 0.02 (0.01) for the MTB group, resulting in a statistically significant treatment difference of 0.22 (0.01), p-value < 0.0001. There were also concomitant reductions in MPI and PPD at Week 24, resulting in statistically significant (p-value < 0.0001) LS Mean (SE) treatment differences of 0.86 (0.04) and 0.24 (0.01), for MPI and PPD, respectively. CONCLUSION: When combined with SRP, daily home oral hygiene maintenance including a powered toothbrush significantly reduced clinical symptoms of periodontitis and surface plaque levels compared to a manual toothbrush in a Stage I/II periodontitis population. (ClinicalTrials.gov Identifier: NCT04254770).

In Esophageal Squamous Cells From Eosinophilic Esophagitis Patients, Th2 Cytokines Increase Eotaxin-3 Secretion Through Effects on Intracellular Calcium and a Non-Gastric Proton Pump.

BACKGROUND & AIMS: In upper airway cells, T helper 2 cytokines that signal through interleukin-4 (IL-4) receptor-α have been shown to stimulate eotaxin-3 secretion via a nongastric proton pump (ngH+,K+ATPase). To seek novel targets for eosinophilic esophagitis (EoE) treatments, we evaluated ngH+,K+ATPase expression in EoE squamous cells, and explored molecular pathways involved in eotaxin-3 secretion by IL-4 receptor-α signaling. METHODS: ngH+,K+ATPase expression in EoE cells was evaluated by quantitative real-time polymerase chain reaction and Western blotting. IL-4-stimulated eotaxin-3 secretion was measured by enzyme-linked immunosorbent assay after treatment with omeprazole, SCH 28080 (potassium-competitive acid blocker), ethylene glycol-bis(ß-aminoethyl)-N,N,N',N'-tetraacetoxymethyl ester (calcium chelator), 2-aminoethoxydiphenyl borate (inhibitor of endoplasmic reticulum calcium release), verapamil, and diltiazem (L-type calcium channel inhibitors). Intracellular calcium transients were measured by Fluo-4 fluorescence. Key experiments were confirmed in EoE primary cells and in RNA sequencing datasets from mucosal biopsies of patients with EoE and controls. RESULTS: EoE cells expressed ngH+,K+ATPase messenger RNA and protein. Omeprazole and SCH 28080 decreased IL-4-stimulated eotaxin-3 secretion. IL-4 increased intracellular calcium transients, and IL-4-stimulated eotaxin-3 secretion was blocked by ethylene glycol-bis(ß-aminoethyl)-N,N,N',N'-tetraacetoxymethyl ester, 2-aminoethoxydiphenyl borate, verapamil, and diltiazem. The combination of omeprazole and verapamil suppressed IL-4-stimulated eotaxin-3 secretion more than either agent alone. EoE biopsies expressed higher ngH+,K+ATPase and exhibited more calcium signaling than controls. CONCLUSIONS: EoE cells express a nongastric proton pump that mediates T helper 2 cytokine-stimulated eotaxin-3 secretion. IL-4 induces calcium release from the endoplasmic reticulum and calcium entry via L-type calcium channels, increasing intracellular calcium that contributes to eotaxin-3 secretion by EoE cells. L-type calcium channel inhibitors block T helper 2 cytokine-stimulated eotaxin-3 secretion, suggesting a potential role for these agents in EoE treatment.

Percutaneous thoraco-lumbar-sacral pedicle screw placement accuracy results from a multi-center, prospective clinical study using a skin marker-based optical navigation system.

STUDY DESIGN: Prospective multi-center study. OBJECTIVE: The study aimed to evaluate the accuracy of pedicle screw placement using a skin marker-based optical surgical navigation system for minimal invasive thoraco-lumbar-sacral pedicle screw placement. METHODS: The study was performed in a hybrid Operating Room with a video camera-based navigation system integrated in the imaging hardware. The patient was tracked with non-invasive skin markers while the instrument tracking was via an on-shaft optical marker pattern. The screw placement accuracy assessment was performed by three independent reviewers, using the Gertzbein grading. The screw placement time as well as the staff and patient radiation doses was also measured. RESULTS: In total, 211 screws in 39 patients were analyzed for screw placement accuracy. Of these 32.7% were in the thoracic region, 59.7% were in the lumbar region, and 7.6% were in the sacral region. An overall accuracy of 98.1% was achieved. No screws were deemed severely misplaced (Gertzbein grading 3). The average time for screw placement was 6 min and 25 secs (± 3 min 33 secs). The average operator radiation dose per subject was 40.3 µSv. The mean patient effective dose (ED) was 11.94 mSv. CONCLUSION: Skin marker-based ON can be used to achieve very accurate thoracolumbarsacral pedicle screw placements.

Comparative cost of diets for low-income families in the Caribbean.

Objective: To assess the ability of low-income families to obtain a standard basket of healthy foods before and during the COVID-19 pandemic. Methods: The costs of 191 food items were averaged from supermarkets, municipal markets, wholesalers, and community food outlets in high- and low-income areas in three Caribbean countries. The analysis compared foods not only by selecting high- and low-ranked commodities but by the proportions of those foods, by food group, that will be required to meet a low-cost, nutritionally balanced diet of 2 400 kcal. Results: The main finding was that low-income households will need between 22% and 47% of their earnings to obtain a healthy diet. Despite higher food prices in Saint Kitts and Nevis, low-income households there will need a smaller proportion of their income to obtain a similar basket of foods than in Jamaica or Saint Vincent and the Grenadines. Conclusions: While the COVID-19 pandemic has added economic stressors to low-income households the basic vulnerability of the poor to obtain a healthy diet remains. Despite country variations, the findings point to the need for an increase in the minimum wage, particularly in Jamaica. It is essential to embed policies that ensure reduced economic and social vulnerability at the household level.

Is Myofascial Decompression Effective at Increasing Hamstring Flexibility in the Athletic Population? A Critically Appraised Topic.

CLINICAL SCENARIO: There are a variety of therapeutic modalities used to treat flexibility issues in athletes, which can be the main cause of hamstring injuries. Myofascial decompression is one modality used to treat these patients. FOCUSED CLINICAL QUESTION: Is myofascial decompression effective at increasing hamstring flexibility in the athletic population? Summary of Search, "Best Evidence" Appraised, and Key Findings: The literature was searched for studies of level 2 evidence or higher that investigated the use of myofascial decompression to increase hamstring flexibility, that were published in the last 5 years. Two high-quality randomized controlled trials were included and one cohort study. CLINICAL BOTTOM LINE: There is not enough consistent, clinically significant, high-level evidence to support the use of myofascial decompression to increase hamstring flexibility. STRENGTH OF RECOMMENDATION: There is level B evidence to support that myofascial decompression is effective at increasing hamstring flexibility.

Mast cell effects on esophageal smooth muscle and their potential role in eosinophilic esophagitis and achalasia.

Mast cells and eosinophils are the key effector cells of allergic disorders. Although most studies on eosinophilic esophagitis (EoE), an allergic disorder of the esophagus, have focused on the role of eosinophils, recent studies suggest a major role for mast cells in causing the clinical manifestations of this disease. Cellular and animal studies have demonstrated that mast cells can cause esophageal muscle cells to proliferate and differentiate into a more contractile phenotype, and that mediators released by degranulating mast cells such as tryptase and histamine can activate smooth muscle contraction pathways. Thus, activated mast cells in the esophageal muscularis propria might cause esophageal motility abnormalities, including the failure of lower esophageal sphincter relaxation typical of achalasia. In addition, mast cells have been implicated in the pathogenesis of a number of neurodegenerative disorders of the central nervous system such as Alzheimer's and Parkinson's diseases, because degranulating mast cells release proinflammatory and cytotoxic mediators capable of damaging neurons. Such mast cell degranulation in the myenteric plexus of the esophagus could cause the loss of enteric neurons that characterizes achalasia. In this report, we review the molecular mechanisms of esophageal smooth muscle contraction, and how mast cells products might affect that muscle and cause neurodegeneration in the esophagus. Based on these data, we present our novel, conceptual model for an allergy-induced form of achalasia mediated by mast cell activation in the esophageal muscularis propria.

Randomized Placebo-Controlled Trial of Topical Mupirocin to Reduce Staphylococcus aureus Colonization in Infants in the Neonatal Intensive Care Unit.

OBJECTIVE: To evaluate the efficacy of topical mupirocin in reducing Staphylococcus aureus colonization in infants in the neonatal intensive care unit (NICU). STUDY DESIGN: A prospective double-blind randomized controlled trial of mupirocin vs placebo in S aureus-colonized infants was conducted in a tertiary care NICU between October 2016 and December 2019. Weekly universal active surveillance with polymerase chain reaction screening identified colonized infants. Colonized infants received a 5-day course of mupirocin (mupirocin group) or petroleum jelly (control group). Repeat courses were given for additional positive screens. RESULTS: A total of 216 infants were enrolled; 205 were included in data analyses. Primary decolonization was more successful for mupirocin-treated infants (86 of 104 [83%]) than for controls (20 of 101; 20%) (P < .001). Although recurrent S aureus colonization occurred frequently (59 of 81 [73%] mupirocin-treated and 26 of 33 [79%] controls), subsequent decolonization remained more successful for mupirocin-treated infants than for controls (38 of 49 [78%] vs 2 of 21 [10%]; P < .001). Subgroup analyses of infants of ≤30 weeks' gestational age yielded similar results; decolonization occurred more often in mupirocin-treated infants compared with control infants (63 of 76 [83%] vs 13 of 74 [18%]; P < .001). Bacterial sterile site infections tended to be less frequent in mupirocin-treated infants compared with controls (2 of 104 [2%] vs 8 of 101 [8%]; P = .057). No invasive S aureus infections occurred in mupirocin-treated infants, but 50% of infections in controls were from S aureus, and 1 resulted in death. CONCLUSIONS: Universal active surveillance and targeted treatment with topical mupirocin is a successful decolonization strategy for NICU infants and may prevent S aureus infection. However, S aureus colonization frequently recurs, necessitating repeat treatment. TRIAL REGISTRATION: Clinicaltrials.gov: NCT02967432.

Reintroduced grazers and prescribed fire effects on beetle assemblage structure and function in restored grasslands.

Ecological restoration seeks to reestablish functioning ecosystems, but planning and evaluation often focus on taxonomic community structure and neglect consumers and their functional roles. The functional trait composition of insect assemblages, which make up the majority of animal diversity in many systems, can reveal how they are affected by restoration management and the consequences for ecosystem function. We sampled ground beetle (Coleoptera: Carabidae) assemblages in restored tallgrass prairies varying in management with prescribed fire and reintroduced American bison (Bison bison) to describe their taxonomic and functional trait structure. We also measured seed and arthropod predation to relate management, beetle assemblage characteristics, and function, and to test if function is maximized by trait diversity, dominant trait values, or beetle abundance. Beetle assemblages primarily varied with restoration age, declining over time in richness and both taxonomic and functional diversity, but bison presence also influenced taxonomic composition. Prescribed fire reduced seed predation in summer and arthropod predation in fall. Although seed predation was unrelated to beetle assemblages, arthropod predation was greater in sites with higher abundances of carnivorous ground beetles. The relatively weak impacts of fire and bison on functional assemblage structure is a promising sign that these management disturbances, aimed at supporting a diverse native plant community, are not detrimental to beetle assemblages. The significance of reduced predator function following prescribed fire will depend on the restoration context and whether seed or arthropod predation relates to management goals.

#ItsNotInYourHead: A Social Media Campaign to Disseminate Information on Provoked Vestibulodynia.

Provoked Vestibulodynia (PVD) is a type of localized vulvodynia (or pain in the vulva). The estimated prevalence of this condition is about 12% of the general population and approximately 20% of women under the age of 19. Many women who live with PVD suffer in silence for years before receiving a diagnosis. Whereas cognitive behavioral therapy (CBT) was already known to be effective for managing symptoms of PVD, there has recently been a published head-to-head comparison of CBT versus mindfulness-based therapy for the primary outcome of pain intensity with penetration. The trial revealed that both treatments were effective and led to statistically and clinically meaningful improvements in sexual function, quality of life, and reduced genital pain, with improvements retained at both 6- and 12-month follow-ups. We then undertook an end-of-grant knowledge translation (KT) campaign focused on the use of social media to disseminate an infographic video depicting the findings. Social media was strategically chosen as the primary mode of dissemination for the video as it has broad reach of audience, the public can access information on social media for free, and it presented an opportunity to provide social support to the population of women with PVD who are characterized as suffering in silence by starting a sensitive and empowering dialogue on a public platform. In this paper, we summarize the social media reach of our campaign, describe how and why we partnered with social media influencers, and share lessons learned that might steer future KT efforts in this field.

Development and reliability assessment of a tool to assess community pharmacist potential to influence prescriber performance on quality measures.

OBJECTIVE: To develop and assess the reliability of a tool that measures community pharmacist potential to influence prescriber quality measure performance. METHODS: Multidisciplinary, health care subject matter experts were convened to determine the criteria that evaluate the community pharmacist's ability to influence quality measure performance and a scoring mechanism. The draft tool was reviewed by investigators and subject matter experts in various health care professional settings to assess face validity and make refinements. Interrater reliability was assessed by 2 independent reviewers using a random 20% sample of the 2017 Merit-based Incentive Payment System (MIPS) measure set. Absolute agreement and kappa statistics were calculated, and the tool was iteratively refined based on the results. The tool was then applied to the full 2017 MIPS measure set by 2 reviewers, and interrater reliability was assessed. RESULTS: The quality measure impact tool-community pharmacy (QMIT-CP) comprised 5 criteria, which assessed the quality measures of the community pharmacist's influence potential. The criteria evaluated whether the quality measures: (1) addressed the use of medications or immunizations; (2) included a condition treatable by medications; (3) treated patients in an outpatient setting; (4) included outcomes; and (5) evaluated whether relevant measure data were available to community pharmacists. All criteria used a dichotomous scale, and the summed scores were used to categorize the pharmacist's influence potential as "high" (4-5), "moderate" (2-3), or "low" (0-1). Kappa statistics ranged from "substantial agreement" (≥0.6) to "almost perfect agreement" (≥0.8) for individual QMIT-CP criteria and overall pharmacist influence potential categorization. CONCLUSIONS: The QMIT-CP is a reliable tool to identify quality measures and assess the high, moderate, or low influence potential that community pharmacists may have. The QMIT-CP can be used to support innovative team-based care and enhance value-based contracting by identifying relevant measures that community pharmacists have the potential to influence.

Prostate-Specific Membrane Antigen-Specific Antitumor Activity of a Self-Immolative Tubulysin Conjugate.

Prostate-specific membrane antigen (PSMA) is a biomarker that is overexpressed on prostate cancer, and it is also present on the neovasculature within many non-prostate solid tumors. Herein, we report on the construction and biological testing of novel tubulysin B-containing therapeutic agents for the treatment of PSMA-expressing cancer. One of these compounds, EC1169, emerged as a lead candidate for preclinical development and phase 1 clinical testing. This water-soluble conjugate was shown to have high affinity for PSMA-positive cells. When tested in vitro, EC1169 was found to inhibit the growth of PSMA-positive cells, but it displayed no activity against PSMA-negative cells. Brief treatment of nude mice bearing PSMA-positive LNCaP human xenografts with EC1169 led to complete remissions and cures. Furthermore, this activity occurred in the absence of weight loss. In contrast, the nontargeted tubulysin B drug proved to be inactive against the LNCaP tumor model when administered at doses near to or greater than the maximum tolerated level. PSMA-negative KB tumors did not appreciably respond to EC1169 therapy, thereby confirming this compound's targeted specificity for PSMA-positive cells. Finally, treatment of LNCaP-bearing mice with docetaxel (the most active chemotherapeutic agent approved for late stage prostate cancer therapy) was found to produce only modest anti-tumor activity, and this outcome was also associated with severe weight loss. Taken together, these results strongly indicate that PSMA-positive tumors may be effectively treated using highly potent, PSMA-targeted small-molecule drug conjugates using regimens that do not cause undesirable side effects.

Detecting Functional and Accessible Folate Receptor Expression in Cancer and Polycystic Kidneys.

Folate-based small molecule drug conjugates (SMDCs) are currently under development and have shown promising preclinical and clinical results against various cancers and polycystic kidney disease. Two requisites for response to a folate-based SMDC are (i) folate receptor alpha (FRα) protein is expressed in the diseased tissues, and (ii) FRα in those tissues is accessible and functionally competent to bind systemically administered SMDCs. Here we report on the development of a small molecule reporter conjugate (SMRC), called EC2220, which is composed of a folate ligand for FRα binding, a multilysine containing linker that can cross-link to FRα in the presence of formaldehyde fixation, and a small hapten (fluorescein) used for immunohistochemical detection. Data show that EC2220 produces a far greater IHC signal in FRα-positive tissues over that produced with EC17, a folate-fluorescein SMRC that is released from the formaldehyde-denatured FRα protein. Furthermore, the extent of the EC2220 IHC signal was proportional to the level of FRα expression. This EC2220-based assay was qualified both in vitro and in vivo using normal tissue, cancer tissue, and polycystic kidneys. Overall, EC2220 is a sensitive and effective reagent for evaluating functional and accessible receptor expression in vitro and in vivo.

Latent Warheads for Targeted Cancer Therapy: Design and Synthesis of pro-Pyrrolobenzodiazepines and Conjugates.

Pyrrolobenzodiazepines (PBDs) and their dimers (bis-PBDs) have emerged as some of the most potent chemotherapeutic compounds, and are currently under development as novel payloads in antibody-drug conjugates (ADCs). However, when used as stand-alone therapeutics or as warheads for small molecule drug conjugates (SMDCs), dose-limiting toxicities are often observed. As an elegant solution to this inherent problem, we designed diazepine-ring-opened conjugated prodrugs lacking the imine moiety. Once the prodrug (pro-PBD) conjugate enters a targeted cell, cleavage of the linker system triggers the generation of a reactive intermediate possessing an aldehyde and aromatic amine. An intramolecular ring-closing reaction subsequently takes place as the aromatic amine adds to the aldehyde with the loss of water to give the imine and, as a result, the diazepine ring. In our pro-PBDs, we mask the aldehyde as a hydrolytically sensitive oxazolidine moiety which in turn is a part of a reductively labile self-immolative linker system. To prove the range of applications for this new class of latent DNA-alkylators, we designed and synthesized several novel latent warheads: pro-PBD dimers and hybrids of pro-PBD with other sequence-selective DNA minor groove binders. Preliminary preclinical pharmacology studies showed excellent biological activity and specificity.

Clinical and Molecular Epidemiology of Methicillin-Resistant Staphylococcus aureus in a Neonatal Intensive Care Unit in the Decade following Implementation of an Active Detection and Isolation Program.

Methicillin-resistant Staphylococcus aureus (MRSA) is a frequent source of infection in the neonatal intensive care unit (NICU), often associated with significant morbidity. Active detection and isolation (ADI) programs aim to reduce transmission. We describe a comprehensive analysis of the clinical and molecular epidemiology of MRSA in an NICU between 2003 and 2013, in the decade following the implementation of an MRSA ADI program. Molecular analyses included strain typing by pulsed-field gel electrophoresis, mec and accessory gene regulator group genotyping by multiplex PCR, and identification of toxin and potential virulence factor genes via PCR-based assays. Of 8,387 neonates, 115 (1.4%) had MRSA colonization and/or infection. The MRSA colonization rate declined significantly during the study period from 2.2 to 0.5/1,000 patient days (linear time, P = 0.0003; quadratic time, P = 0.006). There were 19 cases of MRSA infection (16.5%). Few epidemiologic or clinical differences were identified between MRSA-colonized and MRSA-infected infants. Thirty-one different strains of MRSA were identified with a shift from hospital-associated to combined hospital- and community-associated strains over time. Panton-Valentine leukocidin-positive USA300 strains caused 5 of the last 11 infections. Staphylococcal cassette chromosome mec (SCCmec) types II and IVa and agr groups 1 and 2 were most predominant. One isolate possessed the gene for toxic shock syndrome toxin; none had genes for exfoliative toxin A or B. These results highlight recent trends in MRSA colonization and infection and the corresponding changes in molecular epidemiology. Continued vigilance for this invasive pathogen remains critical, and specific attention to the unique host, the neonate, and the distinct environment, the NICU, is imperative.