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Background Shedding of Clostridioides difficile spores from infected individuals contaminates the hospital environment and contributes to infection transmission. We assessed whether antibiotic selection affects C. difficile shedding and contamination of the hospital environment. Methods In this prospective, unblinded, randomized controlled trial of hospitalized adults with C. difficile infection, patients were randomized 1:1:1 to receive fidaxomicin, oral vancomycin, or metronidazole. The primary outcome was change in environmental contamination rate during treatment. Secondary outcomes included stool shedding, total burden of contamination, and molecular relatedness of stool versus environmental C. difficile isolates. Results Of 33 patients enrolled, 31 (94%) completed the study. Fidaxomicin (−0.36 log10 colony-forming units [CFUs]/d [95% confidence interval (CI), −.52 to −.19]; P Conclusions Fidaxomicin, and to a lesser extent vancomycin, reduces C. difficile shedding and contamination of the hospital environment relative to metronidazole. Treatment choice may play a role in reducing healthcare-associated C. difficile transmission. Clinical Trials Registration NCT02057198.

Background To understand the clinical, bacterial, and host characteristics associated with recurrent Staphylococcus aureus bacteremia (R-SAB), patients with R-SAB were compared to contemporaneous patients with a single episode of SAB (S-SAB). Methods All SAB isolates underwent spa genotyping. All isolates from R-SAB patients underwent pulsed-field gel electrophoresis (PFGE). PFGE-indistinguishable pairs from 40 patients underwent whole genome sequencing (WGS). Acute phase plasma from R-SAB and S-SAB patients was matched 1:1 for age, race, sex, and bacterial genotype, and underwent cytokine quantification using 25-analyte multiplex bead array. Results R-SAB occurred in 69 (9.1%) of the 756 study patients. Of the 69 patients, 30 experienced relapse (43.5%) and 39 reinfection (56.5%). Age, race, hemodialysis dependence, presence of foreign body, methicillin-resistant Staphyloccus aureus, and persistent bacteremia were individually associated with likelihood of recurrence. Multivariate risk modeling revealed that black hemodialysis patients were nearly 2 times more likely (odds ratio [OR] = 9.652 [95% confidence interval [CI], 5.402–17.418]) than white hemodialysis patients (OR = 4.53 [95% CI, 1.696–10.879]) to experience R-SAB. WGS confirmed PFGE interpretations in all cases. Median RANTES (regulated on activation, normal T cell expressed and secreted) levels in acute phase plasma from the initial episode of SAB were higher in R-SAB than in matched S-SAB controls (P = .0053, false discovery rate Conclusion This study identified several risk factors for R-SAB. The largest risk for R-SAB is among black hemodialysis patients. Higher RANTES levels in R-SAB compared to matched controls warrants further study.

Elective surgical patients routinely bathe with chlorhexidine gluconate (CHG) at home days prior to their procedures. However, the impact of home CHG bathing on surgical site CHG concentration is unclear. We examined 3 different methods of applying CHG and hypothesized that different application methods would impact resulting CHG skin concentration.

Background We conducted a longitudinal study to evaluate changes in the clinical presentation and epidemiology of Staphylococcus aureus bacteremia (SAB) in an academic, US medical center. Methods Consecutive patients with monomicrobial SAB were enrolled from January 1995 to December 2015. Each person’s initial bloodstream S. aureus isolate was genotyped using spa typing. Clonal complexes (CCs) were assigned using Ridom StaphType software. Changes over time in both the patient and bacterial characteristics were estimated with linear regression. Associations between genotypes or clinical characteristics and complications were estimated using multivariable regression models. Results Among the 2348 eligible participants, 54.2% had an implantable, foreign body of some type. This proportion increased significantly during the 21-year study period, by 0.96% annually (P = .002), as did comorbid conditions and acquisition outside of the hospital. Rates of any metastatic complication also significantly increased, by 0.94% annually (P = .019). Among the corresponding bloodstream S. aureus isolates, spa-CC012 (multi-locus sequence type [MLST] CC30), -CC004 (MLST CC45), -CC189 (MLST CC1), and -CC084 (MLST CC15) all significantly declined during the study period, while spa-CC008 (MLST CC8) significantly increased. Patients with SAB due to spa-CC008 were significantly more likely to develop metastatic complications in general, and abscesses, septic emboli, and persistent bacteremia in particular. After adjusting for demographic, racial, and clinical variables, the USA300 variant of spa-CC008 was independently associated with metastatic complications (odds ratio 1.42; 95% confidence interval 1.02–1.99). Conclusions Systematic approaches for monitoring complications of SAB and genotyping the corresponding bloodstream isolates will help identify the emergence of hypervirulent clones and likely improve clinical management of this syndrome.

Group Name: Duke Center for Antimicrobial Stewardship and Infection PreventionBackground: Blood cultures are an essential diagnostic test, but over- and underutilization may cause harm. Methods: We analyzed blood culture utilization at 6 hospitals in the southeastern United States including 1 academic hospital (A) and 5 community hospitals (B–F) from May 2019 to April 2020. We measured blood culture utilization rate (BCUR) per 1,000 patient days and blood cultures per encounter. We counted blood cultures by laboratory accession number and measured utilization per 1,000 patient days and encounter. A likely contaminant was defined as 1 of 2 blood cultures collected in the same calendar day positive for a common skin commensal (CSC), as defined by the NHSN, and not identified from subsequent cultures. A likely pathogen was defined as a culture with a pathogen not on the CSC list or a CSC not meeting the contaminant definition. Hospital-level BCUR included samples for culture collected in the emergency department (ED) and inpatient areas divided by inpatient days. Results: The analysis included 117,897 blood cultures and 662,723 patient days with a median BCUR of 209.7 per hospital and median blood culture per encounter of 2 (Table 1). One community hospital (C) demonstrated a substantially higher BCUR than others. Cultures were frequently collected in the ED (54%; range, 36%–78%); most encounters with cultures in the ED were subsequently admitted to an inpatient unit (84%; range, 73%–89%). Higher BCURs were observed in intensive care and oncology units. The proportion of first blood cultures drawn after initiation of antibiotics was 6% (range, 3%–9%. Mondays had higher BCURs than other days of the week (Figure 1). The average BCUR by month was 176.1 (range, 164.3–181.4) with no seasonal patterns observed. Overall, 7.7% (range, 4.5%–9.1%) of blood cultures identified a likely pathogen and 2.1% (range, 1.3%–3.2%) identified a likely contaminant. The 3 hospitals with BCURs >200 also had contaminant rates >2% and >60% ED cultures. Conclusions: Blood culture utilization varied by hospital, unit, and day of the week. We observed higher rates of likely contaminants among hospitals with higher BCURs and ED culture rates. Comparisons may assist in identifying opportunities to optimize practice around blood-culture ordering and collection.Funding: NoDisclosures: None

Background Our primary objective was to determine the effectiveness of 2 enhanced disinfection strategies compared with standard disinfection: “near-UV” light (Arm 1) and a persistent organosilane quaternary ammonium disinfectant (Arm 2) using a triple-blind study design. Our secondary objective was to characterize environmental contamination of outpatient clinics. Methods This trial was conducted at 2 clinics: the wound and pulmonary outpatient clinics at Duke University Health System in Durham, North Carolina. In Arm 1, room overhead lights were replaced with 405-nm near-UV visible light bulbs. In Arm 2, the organosilane quaternary ammonium disinfectant was applied to all room surfaces. The control arm received no intervention. All arms received routine disinfection. Room contamination was measured twice daily (before and after clinic) over 25 clinic days. Results The primary outcome was the change in total contamination, measured in colony forming units (CFUs), on environmental surfaces at the end of the clinic day compared with the beginning of the clinic day. Results from each intervention arm were compared against results from the control arm. The median delta total CFU for Arm 1 was 2092 CFUs (interquartile range [IQR], −1815 to 8566); the median delta for Arm 2 was 2016 CFUs (IQR, −1443 to 7430). Compared with the control arm (median delta = 1987 [IQR, −1611 to 15 857]), neither intervention led to a significant decrease in daily room contamination change (P for Arm 1 = 0.78 and P for Arm 2 = 0.71). Conclusions Neither near-UV lights or a persistent organosilane quaternary ammonium disinfectant reduced environmental contamination in 2 outpatient clinics compared with control rooms but did reduce the number of clinically important pathogens recovered.

Background Meningitis caused by methicillin resistant Staphylococcus aureus (MRSA) is rare and often fatal. The recommended treatment for MRSA meningitis, vancomycin, is limited by poor cerebrospinal fluid (CSF) penetration. Ceftaroline fosamil is a novel fifth-generation cephalosporin with potent antibacterial activity in vitro against MRSA. Several case reports in humans suggest that ceftaroline might be a potential treatment option for MRSA meningitis. Our primary objective was to com­pare the efficacy of ceftaroline and vancomycin for the treatment of MRSA meningitis using a rabbit meningitis model. We then characterized CSF drug concentrations over time.Methods Ninety rabbits received a direct intracisternal injection of 5 x 105 CFU S. aureus (MRSA 252). Following a 16-hour incubation period, approximately 0.5ml of CSF was withdrawn via intracisternal aspiration immediately prior to treatment for quantitative bacterial counts and CSF antibiotic concentrations. Rabbits then received (by 1:1:1 random assignment) either no treatment (control group), vancomycin 20 mg/kg at 0 and 12hrs, or ceftaroline 40mg/kg at 0 and 4 hrs via marginal ear vein. CSF collection was repeated every 12 hours for up to 40 hours. All animals were humanely euthanized at 40 hours post inoculation. The primary endpoint (difference in bacterial load [expressed as CFU/mL] for each animal between the initial (T1) and terminal (T3) taps were characterized and compared between groups using the Kruskal-Wallis test. CSF drug concentrations were determined using liquid chromatography with tandem mass spectrometry (LC/MS/MS) assay.ResultsAmong the forty-three evaluable animals with established MRSA meningitis, there was no statistical difference in median CFU observed between the groups in pretreatment CFU counts (p=0.16). Reductions in bacterial load from baseline were 88%, 79% and 75% in the control, ceftaroline and vancomycin-treated groups, respectively. There was no statistical difference observed between vancomycin and either control or ceftaroline at any time point. While animals treated with ceftaroline exhibited a significant increase in clearance rate (log ∆) between T1 and T2 when compared to control (p = 0.019), these differences were no longer statistically significant by T3 (p= 0.43) as CSF ceftaroline concentrations were undetectable by that time point.Conclusions While ceftaroline may be a reasonable alternative to vancomycin for MRSA meningitis, additional animal and clinical studies are required to determine optimal dosing to establish its effectiveness.

Group Name: Duke Center for Antimicrobial Stewardship and Infection PreventionBackground: Wastewater drains in hospital patient rooms have been identified as environmental reservoirs for multidrug-resistant organisms, and they have been linked to outbreaks of carbapenem-resistant Enterobacteriaceae (CRE). We studied the colonization of wastewater drains in a new hospital bed tower. Methods: A patient care unit in a new bed tower opened on July 18, 2020. In-room sinks were located in each hospital room opposite the patient head wall. Patients admitted to this unit underwent weekly rectal cultures to survey for carbapenemase-producing CRE. Additionally, infection preventionists performed routine surveillance of all clinical cultures for CRE. Cultures were performed from all patient room sinks in this unit monthly beginning September 14, 2020. Samples were obtained from the drain cover, handles, and top of bowl using sponges soaked in neutralizing buffer and processed using the stomacher technique. The tail-pipe was sampled using a flocked mini-tip swab soaked in neutralizing buffer; the P-trap water was sampled with sterile tubing attached to a 50-mL syringe. All samples were plated on HARDYCHROM-ESBL and KPC Colorex media and were incubated at 37°C for 24 hours. Results: The first identified CRE-positive patient was admitted to the new unit on December 4, 2020; urine culture obtained at the time of admission grew KPC–producing Klebsiella pneumoniae (KPC-KP). The sink in this patient’s room had been sampled 3 prior times (most recently on November 9, 2020) and was negative for CRE. On December 7, 2020, KPC-KP was found on the drain cover (6,750 colony-forming units, CFU) and in the sink’s P-trap (1,840 CFU) of the index patient’s room during routine sink surveillance. Additional samples from other room surfaces were taken on December 9, 2020, and KPC-KP was recovered from the computer keyboard (452 CFU) and patient bedrails (880 CFU). The patient was discharged from this room December 13, 2020, and the room underwent enhanced terminal room cleaning including UV-C light. On the next routine sink sampling on January 4, 2021, KPC-KP was recovered again in the index room sink P-trap (9,800 CFU) but at no additional sites. MLST was performed, and all isolates were ST-258. Conclusions: In a new bed tower with no prior evidence of CRE-positive patients, the first identified case of a CRE (KPC-KP) in a patient resulted in widespread environmental contamination of the room after only 3 days of hospitalization and contamination of the in-room sink drain that persisted after 1 month. Given the ease with which CRE colonizes wastewater drains, new strategies are needed to mitigate drain colonization and to prevent CRE transmission to subsequent patients.Funding: NoDisclosures: None

Background: Stethoscopes are a known vector for microbial transmission; however, common strategies used to clean stethoscopes pose certain barriers that prevent routine cleaning after every use. We aimed to determine whether using readily available alcohol-based hand rub (ABHR) would effectively reduce bacterial bioburden on stethoscopes in a real-world setting. Methods: We performed a randomized study on inpatient wards of an academic medical center to assess the impact of using ABHR (AlcareExtra; ethyl alcohol, 80%) on the bacterial bioburden of stethoscopes. Stethoscopes were obtained from healthcare providers after routine use during an inpatient examination and were randomized to control (no intervention) or ABHR disinfection (2 pumps applied to tubing and bell or diaphragm by study personnel, then allowed to dry). Cultures of the tubing and bell or diaphragm were obtained with premoistened cellulose sponges. Sponges were combined with 1% Tween20-PBS and mixed in the Seward Stomacher. The homogenate was centrifuged and all but ~5 mL of the supernatant was discarded. Samples were plated on sheep’s blood agar and selective media for clinically important pathogens (CIPs) including S. aureus, Enterococcus spp, and gram-negative bacteria (GNB). CFU count was determined by counting the number of colonies on each plate and using dilution calculations to calculate the CFU of the original ~5 mL homogenate. Results: In total, 80 stethoscopes (40 disinfection, 40 control) were sampled from 46 physicians (MDs) and MD students (57.5%), 13 advanced practice providers (16.3%), and 21 nurses (RNs) and RN students (26.3%). The median CFU count was ~30-fold lower in the disinfection arm compared to control (106 [IQR, 50–381] vs 3,320 [986–4,834]; P < .0001). The effect was consistent across provider type, frequency of recent usual stethoscope cleaning, age, and status of pet ownership (Fig. 1). Overall, 26 of 80 (33%) of stethoscopes harbored CIP. The presence of CIP was lower but not significantly different for stethoscopes that underwent disinfection versus controls: S. aureus (25% vs 32.5%), Enterococcus (2.5% vs 10%), and GNB (2.5% vs 5%). Conclusions: Stethoscopes may serve as vectors for clean hands to become recontaminated immediately prior to performing patient care activities. Using ABHR to clean stethoscopes after every use is a practical and effective strategy to reduce overall bacterial contamination that can be easily incorporated into clinical workflow. Larger studies are needed to determine the efficacy of ABHR at removing CIP from stethoscopes as stethoscopes in both arms were frequently contaminated with CIP. Prior cleaning of stethoscopes on the study day did not seem to impact contamination rates, suggesting the impact of alcohol foam disinfection is short-lived and may need to be repeated frequently (ie, after each use).Funding: NoneDisclosures: NoneDisclosures: NoneFunding: None

Background: UV-C light reduces contamination of high-touch clinical surfaces. Few studies have tested the relative efficacy of UV-C devices in real-world clinical environments. Methods: We assessed the efficacy of the Tru-D (SmartUVC) and Moonbeam-3 UV-C (Diversey) devices at eradicating important clinical pathogens in 2 hyperbaric chambers at a tertiary-care hospital. Formica sheets were inoculated with 106–107 CFU of MRSA (USA300) or 104–105 CFU of C. difficile (NAP1). Sheets were placed in 6 predetermined locations throughout the chambers. Two Moonbeam-3 UV-C devices were positioned in the center of each chamber and were run for 3-minute (per manufacturer’s instructions) and 5-minute cycles. One Tru-D was positioned in the center of the chamber and was run on the vegetative cycle for MRSA and the spore cycle for C. difficile. UV-C dosage was measured for both machines. Quantitative cultures were collected using Rodac plates with DE neutralizing agar and were incubated at 37C for 48 hours. C. difficile was likewise plated onto sheep’s blood agar. Results: We ran each combination of chamber, microbe, and UV-C device in triplicate for In total, 108 samples per species. For MRSA, the Tru-D vegetative cycle, the 5-minute Moonbeam cycle, and the 3-minute Moonbeam cycle resulted in average CFU log10 reductions of 7.02 (95% CI, 7.02–7.02), 6.99 (95% CI, 6.95–7.02), and 6.58 (95% CI, 6.37–6.79), respectively (Fig. 1). The Tru-D vegetative and 5-minute Moonbeam cycles were similarly effective (P > .99), and both were more effective than the 3-minute Moonbeam cycle (P < .001 and P < .001, respectively). MRSA samples receiving direct UV-C exposure had significantly greater log10 reductions (6.95; 95% CI, 6.89–7.01) than did indirect exposure (6.67; 95% CI, 6.46–6.87; P < .05) (Fig. 2). For C. difficile, the Tru-D sporicidal, the 5-, and 3-minute Moonbeam cycles resulted in average CFU log10 reductions of 1.78 (95% CI, 1.43–2.12), 0.57 (95% CI, 0.33–0.81) and 0.64 (95% CI, 0.42–0.86), respectively (Fig. 1). Tru-D was significantly more effective than either the 3- or 5-minute Moonbeam cycles (P < .00). C. difficile samples receiving direct UV-C exposure had higher dosage and significantly greater log10 reductions (1.34; 95% CI, 1.10–1.58) than did indirect exposure (0.58; 95% CI, 0.31–0.86; P < .01) (Fig. 2). Conclusions: Use of the Tru-D vegetative cycle and the Moonbeam 3- and 5-minute cycles resulted in similar reductions in MRSA; both resulted in significantly greater reductions than the manufacturer’s recommended 3-minute Moonbeam cycle. Therefore, healthcare facilities should carefully evaluate manufacturer-recommended run times in their specific clinical setting. For C. difficile, the Tru-D sporicidal cycle was significantly more effective than either of the Moonbeam cycles, likely due to higher irradiation levels. As such, direct UV-C exposure resulted in greater average reductions than indirect exposure.Funding: NoneDisclosures: None

Background Environmental contamination in outpatient clinics is poorly understood. Methods We performed a microbiological analysis of surfaces in wound and pulmonary outpatient clinics at a tertiary care center. Cultures were obtained with pre-moistened cellulose sponges from three locations (Exam bed/chair, patient chair, physician area/chair) before and after clinic days. Sponges were combined with 1% Tween20-PBS and mixed in the Seward Stomacher. The homogenate was centrifuged and all but 5 mL of the supernatant was discarded. Samples were plated on Sheep’s blood agar and selective media for S. aureus, Enterococcus spp. and Gram-negative bacteria. CFU was determined by counting the number of colonies on each plate and using dilution calculations to calculate the CFU of the original ~5 mL homogenate. The total sample areas in the wound and pulmonary clinic were 12,735 cm2 and 16,400 cm2, respectively. Results A total of 300 samples were obtained over 90-days. Median total room CFU was 7,918 (IQR 2,939–18,855) (Figure 1). Median CFU for the examination area, patient area and physician areas were 2090 (537–10508), 1524 (573–4605) and 960 (371–2183), respectively (Figure 2). The proportions of samples positive for S. aureus, Enterococcus spp. and Gram-negative bacteria were 5.0, 3.3 and 7.7%, respectively (Table 1). In general, median total CFU increased during the clinic day (median CFU before the clinic day 6883 (2937–14983) vs. median after clinic day=10351 (3484–21263) (Figure 3). Environmental bioburden was higher in the wound clinic than the pulmonary clinic (median 18206 CFU [IQR 10048–25037) vs. 3764 [IQR 1452–6671], P < 0.001) (Figure 1). The average number of patients seen in the wound clinic per clinic day was greater than the pulmonary clinic (3.8 vs. 2.2, P < 0.001). Conclusion Outpatient clinic rooms were contaminated with clinically important pathogens. Contamination varied by environmental location and increased as the clinic day progressed. Higher contamination was seen in the wound clinic possibly due to higher patient volume vs. increased environmental contamination that occurs while giving wound care. Wound care clinics may need to focus on more detailed cleaning to reduce environmental contamination and the risk of pathogen transmission in at-risk patients. Disclosures All authors: No reported disclosures.

OBJECTIVETo determine whether antimicrobial-impregnated textiles decrease the acquisition of pathogens by healthcare provider (HCP) clothing.DESIGNWe completed a 3-arm randomized controlled trial to test the efficacy of 2 types of antimicrobial-impregnated clothing compared to standard HCP clothing. Cultures were obtained from each nurse participant, the healthcare environment, and patients during each shift. The primary outcome was the change in total contamination on nurse scrubs, measured as the sum of colony-forming units (CFU) of bacteria.PARTICIPANTS AND SETTINGNurses working in medical and surgical ICUs in a 936-bed tertiary-care hospital.INTERVENTIONNurse subjects wore standard cotton-polyester surgical scrubs (control), scrubs that contained a complex element compound with a silver-alloy embedded in its fibers (Scrub 1), or scrubs impregnated with an organosilane-based quaternary ammonium and a hydrophobic fluoroacrylate copolymer emulsion (Scrub 2). Nurse participants were blinded to scrub type and randomly participated in all 3 arms during 3 consecutive 12-hour shifts in the intensive care unit.RESULTSIn total, 40 nurses were enrolled and completed 3 shifts. Analyses of 2,919 cultures from the environment and 2,185 from HCP clothing showed that scrub type was not associated with a change in HCP clothing contamination (P=.70). Mean difference estimates were 0.118 for the Scrub 1 arm (95% confidence interval [CI], −0.206 to 0.441; P=.48) and 0.009 for the Scrub 2 rm (95% CI, −0.323 to 0.342; P=.96) compared to the control. HCP became newly contaminated with important pathogens during 19 of the 120 shifts (16%).CONCLUSIONSAntimicrobial-impregnated scrubs were not effective at reducing HCP contamination. However, the environment is an important source of HCP clothing contamination.TRIAL REGISTRATIONClinicaltrials.gov Identifier: NCT 02645214Infect Control Hosp Epidemiol 2017;38:1147–1154

Background Clostridium difficile is the leading cause of healthcare-associated infection. As incidence rises, its epidemiology is also evolving. 20–50% of cases are now community-acquired; C. difficile cases arise from more diverse sources than previously thought. In this study, we investigated the diversity of C. difficile within a community hospital. Methods Stool samples were collected from symptomatic adults with a positive C. difficile PCR admitted to Duke Regional Hospital from July 2016 to July 2017. Healthcare-associated CDI was defined by any admission to a hospital, nursing or dialysis facility in the preceding 30 days. C. difficile was isolated by ethanol shock followed by plating on CDSA media. DNA was extracted using a chelex-based protocol. PCR ribotyping was conducted using the Bidet primers and agarose gel electrophoresis. A dendrogram was constructed in Bionumerics by the un-weighted pair-group method with the threshold for identical strains set at 95% similarity. Results C. difficile was successfully isolated from 85% of submitted specimens. For this pilot study, PCR ribotyping was performed on a convenience sample of 70 isolates. C. difficile exhibited substantial diversity: 47 distinct ribotypes were observed among 70 isolates (Figure 1). Fourteen clusters involving identical strain types were observed, totaling 35 isolates. Identical strain types suggestive of direct transmission were evenly split between hospital- (18 of 35, 51%) and community-acquired (17 of 35, 49%) cases. The median time between clustered cases was 50 days (range: 7 to 331 days). Thirty-five of 70 (50%) of all isolates exhibited entirely unique strain types. Conclusion C. difficile isolates in our community hospital exhibited tremendous genetic diversity. The high proportion of strains with entirely unique ribotypes suggests diverse sources of acquisition. These results are consistent with a growing body of literature in which 30–50% of C. difficile isolates are genetically distinct, even when direct transmission was suspected. We are currently expanding our survey to include a network of regional hospitals and clinics, with the goal of better characterizing C. difficile’s diverse and still poorly understood sources. Figure 1. Dendrogram of C. difficile PCR ribotypes. Disclosures All authors: No reported disclosures.

Background Recurrent Staphylococcus aureus bacteremia (Re-SAB) occurs in 2–17% of patients with SAB within 3–12 months after resolution of the first episode. The risk factors for Re-SAB are incompletely understood. Methods Re-SAB was defined as a second episode of SAB after the resolution of the first episode occurring at least 14 days from the date of the last positive blood culture of the first episode. Using the SAB Group Prospective Cohort Study (SABG-PCS) data between January 2008 and May 2015, patients with Re-SAB were selected and compared with those without it. Pulsed-field gel electrophoresis (PFGE) was done for the clinical isolates from the Re-SAB group, and spa typing was for those from both groups. Baseline sera from patients with Re-SAB and age/race/gender matched (1:1) control subjects with SAB but without Recurrence underwent Luminex multiplex cytokine array. Results Seventy patients experienced Re-SAB (9.3%) and 686 SAB patients did not. In the Re-SAB group, 156 episodes of SAB were observed. Median time to Re-SAB was 147.5d (IQR, 76–358). Among 65 PFGE-analyzed pairs of isolates from the first and the subsequent episodes, the time to Re-SAB of Conclusion Re-SAB involves a combination of multiple factors of host, microbe, and treatment. Further laboratory investigation for any determinants in host and microbe is required. Disclosures V. G. Fowler Jr., Merck, Cerexa/Actavis, Pfizer, Advanced Liquid Logis, NIH, MedImmune, Basilea, Karius, Contrafect, Regneron, Genentech, Affinergy, Locus, Medical Surface, Inc., Achaogen, Astellas, Arsanis, Bayer, Cubist, Debiopharm, Durata, Grifols, Medicines Co, Novartis: Collaborator, Consultant and Scientific Advisor, Consulting fee, Research grant and Research support.

Background: Phenol-soluble modulins (PSM) are amphipathic proteins produced by Staphylococcus aureus that promote virulence, inflammatory response, and biofilm formation. We previously showed that MRSA isolates from soft tissue infection (SSTI) produced significantly higher levels of PSM than MRSA isolates from hospital-acquired pneumonia (HAP) or infective endocarditis (IE). In this investigation, we sought to validate this finding in methicillin-susceptible S. aureus (MSSA) isolates. Methods: MSSA isolates (n = 162) from patients with SSTI, HAP, and IE were matched 1:1:1 based on geographic origin of the infection to form 54 triplets (North America n = 27, Europe n = 25, Australia n = 2). All isolates underwent spa typing and were classified using eGenomics. In vitro PSM production was quantified by high-performance liquid chromatography/mass spectrometry. Fischer's Exact Test and the Kruskal-Wallis test were used for statistical analysis. Results: Spa1 was more common in SSTI (14.81% SSTI, 3.70% HAP, 1.85% IE) (< 0.03). Spa2 was more common in HAP (0% SSTI, 12.96% HAP, 3.70% IE) (< 0.01). Levels of PSMα1-all differed significantly among the three clinical groups, with SSTI isolates producing the highest levels and IE producing the lowest levels of PSMα1-4. Spa1 isolates produced significantly more delta-toxin (< 0.03) than non-Spa1 isolates. No associations between PSM levels and clinical outcome of SSTI, HAP, or IE were identified. Conclusion: Production of PSMα1-is highest in SSTI MSSA isolates, supporting the hypothesis that these peptides are important for SSTI pathogenesis. These findings are similar to those described in MRSA, and demonstrate that associations between PSM levels and type of infection are independent of the methicillin-resistance status of the isolate.

Tents meeting current thickness and uniformity/roughness specifications are needed to position ICF target-capsules inside hohlraum assemblies. We have developed a vacuum-forming technique to mold less than 100nm-thick polyimide films into partially-conforming capsule-tents. Characterization of the tents has been performed by an in-house metrology system designed to measure their roughness- and thickness-distributions. This paper will review the results of our tent-forming technique and the characterization of these tents surrounding capsules in hohlraum assemblies.