Background: Persistent colonization with resistant gram-negative bacteria (R-GNB) increases risk of clinical infection and intra-facility transmission among nursing home (NH) patients. Limited data exist on the roles of age and function on duration of R-GNB colonization. Methods: Secondary data analysis was performed from a cohort study of patients admitted to 6 Michigan NHs between November 2013 and May 2018. Swabs obtained upon enrollment, day 14, day 30, then monthly until NH discharge from 6 anatomical sites were cultured for GNB. R-GNB were defined as resistant to ciprofloxacin, ceftazidime, or imipenem. Positive R-GNB culture from a single visit followed by negative cultures for the same organism from ≥2 subsequent visits were defined as transient R-GNB colonization. All other patients with positive R-GNB cultures from multiple visits were considered persistently colonized. Demographic data, antibiotic use, device use, and physical self-maintenance scales (PSMSs) were obtained upon enrollment. Characteristics were compared between patients with transient versus persistent R-GNB and uncolonized patients using multinomial logistic regression. Results: We recruited 896 patients (median age, 75 years; 41% male; 46% nonwhite) and followed them for 2,437 total visits. Of 896 patients, 407 (45.4%) were colonized with ≥1 R-GNB during their stay. Of 171 patients with ≥ 2 follow-up visits after R-GNB detection, 94 (55%) remained persistently colonized with the same R-GNB (Table 1). Escherichia coli (30%) and Proteus mirabilis (22%) were the most frequently identified R-GNB. The most common anatomical colonization sites were perirectal (368 [24.3%] of 1,147) groin (340 [14.3%] of 2,046), and hands (115 [4.8%] of 2283). Compared to uncolonized patients, patients with persistent (1.09; 95% CI, 1.00–1.19, P = .048) and transient R-GNB colonization (1.13; 95% CI, 1.04–1.23; P = .003) had lower PSMS (Tables 2 and 3). Compared to uncolonized and transiently colonized patients, patients with persistent R-GNB colonization had prolonged lengths of NH stay (1.01; 95% CI, 1.00–1.01; P = .003). Conclusions: R-GNB colonization in vulnerable NH patients is common (407 [45.5%] of 896 and often persistent (94 [55%] of 171 patients with sufficient follow-up to assess persistence). Patients with persistent R-GNB had lower functional status, longer LOS, and higher readmission rates than those without. R-GNB decolonization should be investigated as a strategy to potentially improve outcomes among NH patients.

Funding: None

Disclosures: None

Background:Clostridioides difficile infection (CDI) is a major source of morbidity and mortality. Even after recovery, recurrent CDI (rCDI) occurs frequently, and concomitant antibiotic use for treatment of a concurrent non–C. difficile infection is a major risk factor. Treatment with fidaxomicin versus vancomycin is associated with similar rate of cure and lower recurrence risk. However, the comparative efficacy of these 2 agents remains unclear in those receiving concomitant antibiotics. Methods: We conducted a randomized, controlled, open-label trial at the University of Michigan and St. Joseph Mercy hospitals in Ann Arbor, Michigan. Patients provided written informed consent at enrollment. We included all hospitalized patients aged ≥18 years with a positive test for toxigenic C. difficile, >3 unformed stools per 24 hours, and ≥1 qualifying concomitant antibiotic with a planned treatment of an infection for ≥5 days after enrollment. We excluded patients with complicated CDI, allergy to vancomycin–fidaxomicin, planned adjunctive CDI treatments, CDI treatment for >24 hours prior to enrollment, concomitant laxative use, current or planned colostomy or ileostomy, and/or planned long-term (>12 weeks) concomitant antibiotic use. Clinical cure was defined as resolution of diarrhea for 2 consecutive days maintained until the end of therapy and for 2 days afterward. rCDI was defined as recurrent diarrhea with positive testing within 30 days of initial treatment. Patients were randomized (stratified by ICU status) to fidaxomicin 200 mg twice daily or vancomycin 125 mg orally 4 times daily for 10 days. If concomitant antibiotic treatment continued >10 days, the study drug continued until the concomitant antibiotic ended. Bivariable statistics included t tests and χ2 tests. Results: After screening 5,101 patients for eligibility (May 2017–May 2021), 144 were included and randomized (Fig. 1). Study characteristics and outcomes are noted in Table 1. Baseline characteristics were similar between groups. Most patients were aged <65 years, were on a proton-pump inhibitor (PPI), and were not in the ICU. The mean duration of concomitant antibiotic was 18.4 days. In the intention-to-treat population, clinical cure (73% vs 62.9%; P =.195), and rCDI (3.3% vs 4.0%; P >.99) were similar for fidaxomicin and vancomycin, respectively. Conclusions: In this study of patients with CDI receiving a concomitant antibiotic, a numerically higher proportion were cured with fidaxomicin versus vancomycin, but this result did not reach statistical significance. Overall recurrence was lower than anticipated in both arms compared to previous studies in which duration of CDI treatment was not extended during concomitant antibiotic treatment. Future studies are needed to ascertain whether clinical cure is higher with fidaxomicin than vancomycin during concomitant antibiotic exposure, and whether extending the duration of CDI treatment reduces recurrence.

Funding: Merck & Co.

Disclosures: None

A chloroacetamide herbicide by application timing factorial experiment was conducted in 2017 and 2018 in Mississippi to investigate chloroacetamide use in a dicamba-based Palmer amaranth management program in cotton production. Herbicides used were S-metolachlor or acetochlor, and application timings were preemergence, preemergence followed by (fb) early postemergence, preemergence fb late postemergence, early postemergence alone, late postemergence alone, and early postemergence fb late postemergence. Dicamba was included in all preemergence applications, and dicamba plus glyphosate was included with all postemergence applications. Differences in cotton and weed response due to chloroacetamide type were minimal, and cotton injury at 14 d after late postemergence application was less than 10% for all application timings. Late-season weed control was reduced up to 30% and 53% if chloroacetamide application occurred preemergence or late postemergence only, respectively. Late-season weed densities were minimized if multiple applications were used instead of a single application. Cotton height was reduced by up to 23% if a single application was made late postemergence relative to other application timings. Chloroacetamide application at any timing except preemergence alone minimized late-season weed biomass. Yield was maximized by any treatment involving multiple applications or early postemergence alone, whereas applications preemergence or late postemergence alone resulted in up to 56% and 27% yield losses, respectively. While no yield loss was reported by delaying the first of sequential applications until early postemergence, forgoing a preemergence application is not advisable given the multiple factors that may delay timely postemergence applications such as inclement weather.

Native tungsten (IMA2011-004), W, is officially described as a new mineral from gold placers in the Bol'shaya Pol'ya river valley, Prepolar Urals, Russia, associated with yttriaite-(Y) and from quartz veins in the Mt Neroyka rock-crystal field, Ust–Puiva, Tyumenskaya Oblast', Russia. Tungsten forms polycrystalline grains and masses, and rarely cubo-octahedra. It is silver white to steel grey in colour, with metallic lustre and grey streak. The calculated density is 19.226 g/cm3. The Vickers hardness (VHN25) is 571.45 kg/mm2. In plane polarised light, tungsten is white with a pale-yellow tint and optically isotropic. Electron microprobe analyses of Bol'shaya Pol'ya river valley material provided W 99.27, Mo 0.06, Mn 0.04, Fe 0.01, total 99.38 wt.%. The five strongest powder X-ray diffraction lines are [dobs Å(I)(hkl)]: 2.2422(100)(110), 1.5835(25)(200), 1.2929(48)(211), 1.0010(23)(310) and 0.8457(24)(321). Tungsten is cubic, Im$\bar{3}$m, a = 3.1648(4) Å, V = 31.69(4) Å3 and Z = 2. Some additional occurrences of native tungsten and technogenic tungsten found in Nature are also described.

Background: Prevention of central-line–associated bloodstream infections (CLABSIs) and methicillin-resistant Staphylococcus aureus (MRSA) infections requires a multifaceted approach including strategies to decrease cutaneous bacterial colonization. Prior studies have shown benefit from chlorhexidine-gluconate (CHG) skin application on CLABSI and MRSA infection rates in intensive care units (ICUs); however, the use of CHG in the non-ICU population has not been well studied. Methods: We performed a quasi-experimental before-and-after study to evaluate the use of daily 2% CHG wipes in non-ICU patients at a 1,000 bed acute-care teaching hospital beginning in November 2017. The study population included adult and pediatric patients with central venous catheters on non-ICU units, excluding patients on the following units: stem cell transplant and hematologic malignancy (these units had already established use of CHG skin application as a standard prior to the intervention), labor and delivery, and psychiatry. CHG was applied according to the manufacturer’s instruction by nurses or nurse aides and random monthly auditing of compliance was performed. NHSN CLABSI, hospital-onset MRSA bacteremia, and hospital-onset MRSA LabID rates were compared for the period 24 months before the intervention (November 1, 2015, through October 31, 2017) to the 24-month period after the intervention (November 1, 2017, through October 31, 2019) using a paired t test. Notably, the health system also discontinued the use of contact precautions for patients with MRSA (excluding MRSA from open, draining wounds) 11 months prior to onset of this intervention. Results: The CLABSI rate decreased by 26% from 0.594 events per 1,000 central-line days (n = 50) before the intervention to 0.438 events per 1,000 central-line days (n = 38) after the intervention (P = 0.19). The number of CLABSIs with gram-positive organisms also decreased by 29%. MRSA LabID rates decreased by 37% from 0.301 events per 1,000 patient days (n = 119) to 0.189 events per 1,000 patient days (n = 75) (P = 0.01). MRSA bacteremia rates decreased by 79% from 0.058 events per 1,000 patient days (n = 23) to 0.012 events per 1,000 patient days (n = 5) (P < 0.01). Compliance with the intervention was 83% (n = 225). Conclusions: Daily CHG skin application in non-ICU patients with central venous catheters is an effective strategy to prevent CLABSIs and MRSA infections. We observed a decrease in MRSA LabID and bacteremia rates despite discontinuation of contact precautions. These findings suggest that a horizontal prevention approach of daily CHG skin application may be an effective alternative to contact isolation to interrupt transmission of MRSA in hospitalized patients outside the ICU setting.

Funding: None

Disclosures: None

Background: A robust infection prevention infrastructure is critical for creating a safe resident environment in nursing homes. The CDC NHSN provides a standardized approach to infection surveillance and analysis, which can drive internal quality improvement efforts in nursing homes and could serve as an indicator of facilities’ infection prevention aptitude. The purpose of this study was to compare the characteristics of nursing homes enrolled to those not enrolled in the NHSN, including interfacility communication methods, as an essential part of reducing resident infection-related risks. Methods: Over a 2-year period, 50 nursing homes participated in a 12-month program designed to reduce healthcare-associated infections (HAIs) by enhancing relationships between nursing homes and hospitals. Overall, 11 demographic surveys were administered to nursing homes prior to the start of the phase 1 pilot year between January and March 2018, and another 39 were administered prior to beginning phase 2 in January–February 2019. The survey consisted of 36 questions on facility characteristics, including NHSN enrollment, infection prevention and control (IPC) program and infection preventionist characteristics, and communication methods related to interfacility transfer of care. We compared facility, IPC program characteristics, and communication methods between nursing homes stratified based on NHSN enrollment. These were compared using the Fisher exact test. Results: In total, 50 nursing homes, varying in size and services provided, completed the demographic survey (Table 1). Of these 50 nursing homes, 11 (22%) were enrolled in the NHSN. Nursing homes enrolled in the NHSN were more likely to use a telephone report prior to resident transfer in and out of the facility (P = .04) and to disseminate infection data to all facility nursing staff (P = .02). Overall, less than half of nursing homes included a telephone report as part of their routine hand-off communication, and most nursing homes relied only on written transfer forms or discharge documentation. Moreover, 65% of the nursing homes reported use of a standardized method to accept new residents with history of multidrug-resistant organism (MDRO), including a review of infection or MDRO type, antibiotic orders, and ambulation status. NHSN-enrolled nursing homes were also more likely to have an antibiotic stewardship program and to use the electronic health record (EHR) to facilitate infection surveillance, though these differences were not statistically significant. Conclusions: A higher percentage of nursing homes enrolled in the NHSN engaged in activities connected with resident safety including verbal report prior to interfacility transfer and antimicrobial stewardship programs. Dedicating resources for nursing homes to enhance their IPC program including NHSN enrollment should be encouraged.

Funding: This study was supported by a grant from the AHRQ (grant no. RO1HS25451).

Disclosures: None

Wind-driven snow redistribution can increase the spatial heterogeneity of snow accumulation on ice caps and ice sheets, and may prove crucial for the initiation and survival of glaciers in areas of marginal glaciation. We present a snowdrift model (Snow_Blow), which extends and improves the model of Purves, Mackaness and Sugden (1999, Journal of Quaternary Science 14, 313–321). The model calculates spatial variations in relative snow accumulation that result from variations in topography, using a digital elevation model (DEM) and wind direction as inputs. Improvements include snow redistribution using a flux routing algorithm, DEM resolution independence and the addition of a slope curvature component. This paper tests Snow_Blow in Antarctica (a modern environment) and reveals its potential for application in palaeoenvironmental settings, where input meteorological data are unavailable and difficult to estimate. Specifically, Snow_Blow is applied to the Ellsworth Mountains in West Antarctica where ablation is considered to be predominantly related to wind erosion processes. We find that Snow_Blow is able to replicate well the existing distribution of accumulating snow and snow erosion as recorded in and around Blue Ice Areas. Lastly, a variety of model parameters are tested, including depositional distance and erosion vs wind speed, to provide the most likely input parameters for palaeoenvironmental reconstructions.

The mineral ‘oboyerite’, first described in 1979 from the Grand Central mine, Tombstone, Cochise County, Arizona, USA, has been re-examined. The type specimen from the Natural History Museum, London and a specimen from the Natural History Museum of Los Angeles County (traceable to S. A Williams, who first described ‘oboyerite’) were analysed in this study. The discreditation of ‘oboyerite’ as a valid mineral species has been approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (Proposal 19-D). Single-crystal X-ray diffraction, powder X-ray diffraction, electron probe microanalysis and scanning electron microscopy were all employed to show that ‘oboyerite’ is formed of at least two distinct phases, including the lead–tellurium oxysalt minerals ottoite and plumbotellurite. During the course of the discreditation, plumbotellurite was confirmed to be identical to the synthetic compound α-Pb2+Te4+O3. Previously, in some mineralogical literature plumbotellurite was described as orthorhombic with no known crystal structure.

A 2018 workshop on the White Mountain Apache Tribe lands in Arizona examined ways to enhance investigations into cultural property crime (CPC) through applications of rapidly evolving methods from archaeological science. CPC (also looting, graverobbing) refers to unauthorized damage, removal, or trafficking in materials possessing blends of communal, aesthetic, and scientific values. The Fort Apache workshop integrated four generally partitioned domains of CPC expertise: (1) theories of perpetrators’ motivations and methods; (2) recommended practice in sustaining public and community opposition to CPC; (3) tactics and strategies for documenting, investigating, and prosecuting CPC; and (4) forensic sedimentology—uses of biophysical sciences to link sediments from implicated persons and objects to crime scenes. Forensic sedimentology served as the touchstone for dialogues among experts in criminology, archaeological sciences, law enforcement, and heritage stewardship. Field visits to CPC crime scenes and workshop deliberations identified pathways toward integrating CPC theory and practice with forensic sedimentology’s potent battery of analytic methods.

Clinical Enterobacteriacae isolates with a colistin minimum inhibitory concentration (MIC) ≥4 mg/L from a United States hospital were screened for the mcr-1 gene using real-time polymerase chain reaction (RT-PCR) and confirmed by whole-genome sequencing. Four colistin-resistant Escherichia coli isolates contained mcr-1. Two isolates belonged to the same sequence type (ST-632). All subjects had prior international travel and antimicrobial exposure.

Recent commercialization of auxin herbicide–based weed control systems has led to increased off-target exposure of susceptible cotton cultivars to auxin herbicides. Off-target deposition of dilute concentrations of auxin herbicides can occur on cotton at any stage of growth. Field experiments were conducted at two locations in Mississippi from 2014 to 2016 to assess the response of cotton at various growth stages after exposure to a sublethal 2,4-D concentration of 8.3 g ae ha−1. Herbicide applications occurred weekly from 0 to 14 weeks after emergence (WAE). Cotton exposure to 2,4-D at 2 to 9 WAE resulted in up to 64% visible injury, whereas 2,4-D exposure 5 to 6 WAE resulted in machine-harvested yield reductions of 18% to 21%. Cotton maturity was delayed after exposure 2 to 10 WAE, and height was increased from exposure 6 to 9 WAE due to decreased fruit set after exposure. Total hand-harvested yield was reduced from 2,4-D exposure 3, 5 to 8, and 13 WAE. Growth stage at time of exposure influenced the distribution of yield by node and position. Yield on lower and inner fruiting sites generally decreased from exposure, and yield partitioned to vegetative or aborted positions and upper fruiting sites increased. Reductions in gin turnout, micronaire, fiber length, fiber-length uniformity, and fiber elongation were observed after exposure at certain growth stages, but the overall effects on fiber properties were small. These results indicate that cotton is most sensitive to low concentrations of 2,4-D during late vegetative and squaring growth stages.

The crystal structure of tlapallite has been determined using single-crystal X-ray diffraction and supported by electron probe micro-analysis, powder diffraction and Raman spectroscopy. Tlapallite is trigonal, space group P321, with a = 9.1219(17) Å, c = 11.9320(9) Å and V = 859.8(3) Å3, and was refined to R1 = 0.0296 for 786 reflections with I > 2σ(I). This study resulted from the discovery of well-crystallised tlapallite at the Wildcat prospect, Utah, USA. The chemical formula of tlapallite has been revised to (Ca,Pb)3CaCu6[Te4+3Te6+O12]2(Te4+O3)2(SO4)2·3H2O, or more simply (Ca,Pb)3CaCu6Te4+8Te6+2O30(SO4)2·3H2O, from H6(Ca,Pb)2(Cu,Zn)3(TeO3)4(TeO6)(SO4). The tlapallite structure consists of layers containing distorted Cu2+O6 octahedra, Te6+O6 octahedra and Te4+O4 disphenoids (which together form the new mixed-valence phyllotellurate anion [Te4+3Te6+O12]12−), Te4+O3 trigonal pyramids and CaO8 polyhedra. SO4 tetrahedra, Ca(H2O)3O6 polyhedra and H2O groups fill the space between the layers. Tlapallite is only the second naturally occurring compound containing tellurium in both the 4+ and 6+ oxidation states with a known crystal structure, the other being carlfriesite, CaTe4+2Te6+O8. Carlfriesite is the predominant secondary tellurium mineral at the Wildcat prospect. We also present an updated structure for carlfriesite, which has been refined to R1 = 0.0230 for 874 reflections with I > 2σ(I). This updated structural refinement improves upon the one reported previously by refining all atoms anisotropically and presenting models of bond valence and Te4+ secondary bonding.