Mandrekar, Jayawant N.

Abstract Background Pre-travel consultation involves an in-clinic face-to-face consult (F2F) with a Travel Medicine provider. F2F involves education/counseling which is time-consuming for both patients and providers. Although electronic consultations (synchronous and asynchronous) are well established in many subspecialties, pretravel eConsults are not well known. We compared pretravel education via F2F to an innovative hybrid electronic consultation (HeC) combined with a Video Supported PowerPoint (VSP) for selected travelers. Methods We conducted a prospective trial comparing HeC-VSP to F2F to determine the quality of pretravel education. Study was approved by the Mayo Clinic IRB. Patients were enrolled from May 2014 through May 2015. Patients in both arms were given pretravel and post-travel surveys. Exclusions included age less than 18 years, first trip to Africa, immunocompromised host, non-English-speaking traveler, or travel for longer than 4 weeks. Results 194 patients were enrolled; 100 in HeC-VSP and 94 in F2F arm completed pretravel survey. Post-travel survey was completed in 54.2% (51/94) of the F2F, 67% (67/100) in the HeC-VSP group. The groups are similar in demographics and prior travel experience (Table 1). 36.2% of the F2F group felt that the consultation could have been effectively accomplished through a video-based education, while 33% felt that a F2F was needed; in contrast a majority (63.3%) in the HeC-VSP group would not have preferred a F2F consultation. HeC-VSP-based pretravel education was similar compared with that provided via the F2F consults. There were no statistically significant differences in the responses obtained in both groups to knowledge assessment questions (Table 2) except for one question. A higher proportion (76/100; 76%) in the HeC-VSP group compared with 55.4% (51/94) chose the correct response (P = 0.0018) regarding management of bloody diarrhea with fever. Self-reported change in behaviors to prevent travel-related illnesses was reported overall in 53% of the patients with no statistically significant differences between the groups. Conclusion Nonsynchronous eConsultation combined with VSP provides a viable solution to provide pretravel education for a select travel population. Disclosures All authors: No reported disclosures.

Abstract Background Orthopedic foreign body-associated infection can be difficult to treat due to the formation of biofilms protecting microorganisms from both antimicrobials and the immune system. Exebacase (EXE) is a phage-derived lysin which acts as a direct lytic agent by hydrolyzing the peptidoglycan cell wall of Staphylococcus aureus. In this study, the activity of EXE was evaluated in comparison to daptomycin against MRSA biofilms on orthopedic Kirschner wires (K-wires). Methods MRSA strain IDRL-6169 was studied; it has a MIC of 0.5 µg/mL for both daptomycin (DAP) and EXE. Biofilms were formed in 1 mL of 106 cfu/mL tryptic soy broth on 0.5x0.1 mm threaded stainless steel K-wires for 10 hours, after which the wires were removed from the media and placed into 0.04 mL of either DAP or EXE at 0 (vehicle only), 0.098, 0.98, or 9.8 mg/mL. DAP+EXE was also tested, each at 0.098 mg/mL. Bacteria were quantified after 0, 2, 4, 8, and 12 hours of incubation at 37ºC. Testing was performed in triplicate. Results were reported as log10 cfu/K-wire reduction relative to vehicle alone. A 3-log10 cfu/K-wire reduction was considered bactericidal. P-values were calculated using Kruskal–Wallis. Results The bacterial burden of vehicle alone ranged from 5.49- to 6.33-log10 cfu/K-wire at all time points. Bacterial reductions for each treatment compared with carrier solution are shown in the table. DAP showed no bactericidal activity. EXE showed bactericidal activity at all concentrations at all time points studied except 0.098 mg/mL at 8 hours. There was no significant difference between EXE at 0.098 and 0.98 mg/mL at any time point but EXE at 9.8 mg/mL did show superiority over the lower concentrations. DAP+EXE 0.098 mg/mL was bactericidal at all time points. Conclusion EXE showed a rapid effect against MRSA biofilms on orthopedic K-wires apparent within the first 2 hours of exposure and was more active than daptomycin alone at the same concentrations. Disclosures All authors: No reported disclosures.

Abstract BACKGROUND: S-adenosyl-L-methionine (AdoMet or SAM-e®) is a commonly used nutritional supplement available in the United States since 1999. AdoMet is metabolized to homocysteine (Hcy), a potential cardiovascular risk factor. A few open-label, single-arm studies have reported on the effect of exogenous AdoMet on the levels of Hcy in humans; however, this has not been tested in a double-blind, randomized clinical trial. As a nutritional supplement, AdoMet is subject only to limited regulation by the FDA, despite being used to treat clinical diseases such as depression and osteoarthritis. AdoMet is the methyl donor for small molecule, DNA, RNA, and protein methylation reactions; therefore, further understanding the biology of the AdoMet/Hcy system is important. We hypothesized that exogenous AdoMet would increase plasma Hcy levels. METHODS: In a double-blind, placebo-controlled, randomized clinical trial, 93 healthy human subjects were screened and 52 were treated with placebo (26) or 800 mg per day AdoMet (26) pills for 4 weeks. Pre- and post-treatment Hcy levels were measured. The primary endpoint was change in Hcy level. Secondary endpoints included an interim Hcy level, high sensitivity C-reactive protein (hsCRP) levels, lipid profile, and transaminases. Exclusion criteria included pregnancy and concurrent use of medications associated with changes in Hcy. RESULTS: Of 52 subjects enrolled, 45 were evaluable at the end of treatment. Subject characteristics and dropout rates were similar between placebo and control groups. Adverse events were minor and were not different between placebo and AdoMet. The primary endpoint, change in Hcy, was not significantly different between the groups (mean (umol/L), baseline: 7.43 (placebo), 8.25 (AdoMet), P=0.358; 4 week: 7.66 (placebo), 8.06 (AdoMet), P = 0.683; Baseline − 4 week: 0.23 (placebo), −0.19 (AdoMet), P = 0.427). No statistically significant difference in change in Hcy or hsCRP at 2 or 4 weeks was noted. This was true for both absolute differences as well as relative percent changes. A small decrease in ALT was observed at 2 weeks in the AdoMet group compared to the placebo group (P = 0.027). AdoMet is used in the treatment of liver diseases. There was a small, but statistically significant (P = 0.028) decrease in total cholesterol in the AdoMet group as compared to the placebo group. Interestingly, a subject with the highest baseline Hcy level had a decline in Hcy on AdoMet. Study limitations include no evaluation of AdoMet serum levels or measurement of the effect of AdoMet on DNA methylation patterns. CONCLUSIONS: AdoMet seems well tolerated and in a dose of 800 mg/day for 4 weeks does not appear to significantly affect Hcy levels in the blood. Future clinical trials of AdoMet should monitor Hcy levels with extended use of AdoMet to confirm its safety with long term use. Clinicaltrials.gov ID: NCT00284011.

Bacteriophage-derived lysins are being developed as anti-infective agents. In an acute osteomyelitis methicillin-resistant Staphylococcus aureus (MRSA) model, rats receiving no treatment or treatment with daptomycin, exebacase (CF-301), or daptomycin plus exebacase had means of 5.13, 4.09, 4.65, and 3.57 log 10 CFU/gram of bone, respectively.

Abstract Background Sonicate fluid (SF), a solution derived from vortexing and sonication of explanted cardiovascular implantable electronic devices (CIEDs), is a higher-yield specimen compared with swabs or tissues for culture-based detection of microorganisms associated with CIED infection. Despite this, SF culture fails to identify a causative organism in ~50% of cases. We aimed to evaluate the diagnostic performance of 16S ribosomal RNA gene (rRNA) polymerase chain reaction (PCR)/sequencing of SF and compare it with that of SF culture. Methods We identified 322 SF specimens from extracted CIEDs and reviewed clinical data for each patient. Subjects were classified as having or not having CIED infection. Cases were subcategorized as culture negative if no significant growth was reported from SF cultures and as culture positive if an organism was detected above predefined thresholds. 16S rRNA PCR/sequencing was performed, with the organisms identified reported according to Clinical and Laboratory Standards Institute guidelines for sequence data interpretation. Results A total of 278 SF samples corresponded to infected cases, of which 160 were culture positive and 118 culture negative. The remaining 44 were from noninfected cases, of which 2 were culture positive. Compared with SF culture, the sensitivity of 16S rRNA PCR/sequencing was higher (64% vs 57.5%, P = .003). 16S rRNA PCR/sequencing detected a potential pathogen in 28 of 118 culture-negative cases, identifying staphylococci in the majority (18/28). Conclusions 16S rRNA PCR/sequencing has higher sensitivity to detect bacteria in SF from extracted CIEDs than does SF culture.

ABSTRACTWe are developing electrical approaches to treat biofilm‐associated orthopedic foreign‐body infection. Although we have previously shown that such approaches have antibiofilm activity, the effects on bone have not been assessed. Herein, low‐amperage 200 μA fixed direct current (DC) was compared with no current, in a rat femoral foreign‐body infection model. In the infected group, a platinum implant seeded with S. epidermidis biofilm (105 CFU/cm2), plus 50 μL of a 109 CFU suspension of bacteria, were placed in the femoral medullary cavity of 71 rats. One week later, rats were assigned to one of four groups: infected with no current or DC, or uninfected with no current or DC. After 2 weeks, bones were removed and subjected to histopathology, micro‐computed tomography (μCT), and strength testing. Histopathology showed no inflammation or bony changes/remodeling in the uninfected no current group, and some osteoid formation in the DC group; bones from the infected no current group had evidence of inflammation without bony changes/remodeling; along with inflammation, there was moderate osteoid present in the DC group. μCT showed more cortical bone volume and density, trabecular thickness, and cancellous bone volume in the DC group compared with the no current group, for both uninfected and infected bones (p < 0.05). There was no difference in torsional strength or stiffness between the no current versus DC groups, for both infected and uninfected bones (p > 0.05). © 2018 The Authors. JBMR Plus Published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research.

Metagenomic shotgun sequencing has the potential to transform how serious infections are diagnosed by offering universal, culture-free pathogen detection. This may be especially advantageous for microbial diagnosis of prosthetic joint infection (PJI) by synovial fluid analysis since synovial fluid cultures are not universally positive and since synovial fluid is easily obtained preoperatively.

ABSTRACT We have previously demonstrated that culturing periprosthetic tissue in blood culture bottles (BCBs) improves sensitivity compared to conventional agar and broth culture methods for diagnosis of prosthetic joint infection (PJI). We have also shown that prosthesis sonication culture improves sensitivity compared to periprosthetic tissue culture using conventional agar and broth methods. The purpose of this study was to compare the diagnostic accuracy of tissue culture in BCBs (subsequently referred to as tissue culture) to prosthesis sonication culture (subsequently referred to as sonicate fluid culture). We studied 229 subjects who underwent arthroplasty revision or resection surgery between March 2016 and October 2017 at Mayo Clinic in Rochester, Minnesota. Using the Infectious Diseases Society of America (IDSA) PJI diagnostic criteria (omitting culture criteria) as the gold standard, the sensitivity of tissue culture was similar to that of the sonicate fluid culture (66.4% versus 73.1%, P = 0.07) but was significantly lower than that of the two tests combined (66.4% versus 76.9%, P < 0.001). Using Bayesian latent class modeling, which assumes no gold standard for PJI diagnosis, the sensitivity of tissue culture was slightly lower than that of sonicate fluid culture (86.3% versus 88.7%) and much lower than that of the two tests combined (86.3% versus 99.1%). In conclusion, tissue culture in BCBs reached sensitivity similar to that of prosthesis sonicate fluid culture for diagnosis of PJI, but the two tests combined had the highest sensitivity without compromising specificity. The combination of tissue culture in BCBs and sonicate fluid culture is recommended to achieve the highest level of microbiological diagnosis of PJI.