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Escherichia coli sequence type (ST) ST131, with its emergent resistance-associated H30Rx, H30R1, and C1-M27 clonal subsets, accounts for the greatest share of extraintestinal E. coli infections and most extended-spectrum β-lactamase (ESBL)-producing E. coli.We characterized and compared consecutive E. coli urine isolates from two geographically distinct medical centers in Minneapolis, Minnesota (n = 172) and Boston, Massachusetts (n = 143) for ESBL phenotype, CTX-M-type ESBL genes, phylogenetic groups, selected ST131 subclones, and 40 extraintestinal virulence genes.Whereas the Boston vs. Minneapolis isolates had a similar prevalence of phylogenetic groups (mainly B2: 79% vs 73%), ST131 (34% vs 28%), H30 (28% vs 21%), and H30Rx (6% vs 5%), the emerging C1-M27 subclone occurred uniquely among Boston (6%) isolates. ESBL production was more prevalent among Boston isolates (15% vs 8%) and among ST131 isolates. Identified ESBL genes included blaDespite numerous similarities to Minneapolis isolates, Boston ST131 isolates demonstrated more prevalent ESBL production, higher virulence gene scores, and, uniquely, the C1-M27 subclone and bla

Fosfomycin has been shown to have a wide spectrum of activity against multidrug-resistant gram-negative bacteria; however, breakpoints have been established only for Escherichia coli or Enterobacterales per the Clinical and Laboratory Standards Institute (CLSI) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST), respectively. Lack of additional organism breakpoints limits clinical use of this agent and has prompted extrapolation of these interpretive categories to other organisms like Pseudomonas aeruginosa without supporting evidence. Further complicating the utility of fosfomycin is the specified method for minimal inhibitory concentration determination, namely agar dilution, which is not widely available and is both labor- and time-intensive. We therefore sought to determine the susceptibility of a large international collection of P. aeruginosa isolates (n = 198) to fosfomycin, and to compare testing agreement rates across four methods: agar dilution, broth microdilution, disk diffusion, and Etest. Results were interpreted according to CLSI E. coli breakpoints with 49.0-85.8% considered susceptible, dependent upon the testing method used. Epidemiological cutoff values were calculated and determined to be 256 μg/mL or 512 μg/mL for agar dilution and broth microdilution, respectively. Agreement rates were analyzed using both agar dilution and broth microdilution with a resulting high essential agreement rate of 91.3% between the two susceptibility testing methods. These results indicate that broth microdilution may be a reliable method for fosfomycin susceptibility testing against P. aeruginosa and stress the need for P. aeruginosa-specific breakpoints.

Antimicrobial peptides may be alternatives to traditional antibiotics with reduced bacterial resistance. The antimicrobial peptide GL13K was derived from the salivary protein BPIFA2. This study determined the relative activity of the L-and D-enantiomers of GL13K to wild-type and drug-resistant strains of three gram-negative species and against Pseudomonas aeruginosa biofilms. DGL13K displayed in vitro activity against ESBL and KPC-producing Klebsiella pneumoniae (MICs 16-32 μg/ml), MDR and XDR P. aeruginosa, and XDR Acinetobacter baumannii carrying metallo-beta-lactamases (MICs 8-32 μg/ml). P. aeruginosa showed low inherent resistance to DGL13K and the increased metabolic activity and growth caused by sub-MIC concentrations of GL13K peptides did not result in acquired bacterial resistance. Daily dosing for approximately two weeks did not increase the MIC of DGL13K or cause cross-resistance between LGL13K and DGL13K. These data suggest that DGL13K is a promising candidate antimicrobial peptide for further development.

There is growing awareness about the potential benefit of harnessing citizen science for research, particularly in the biological and environmental sciences. Data quality is a major constraint in the use of citizen-science data, in particular, imperfect observations. In this paper, we fit species distribution models to presence-only data (presences and counts, with no absences observed) by exploiting the uncertainty in reported presences, instead of generating pseudo-absences as is common in previous presence-only studies. This approach allowed us to extend the suite of models to include those commonly fit to presence/absence and abundance data. We fit several models to a case study data set of jaguar encounters reported by citizens in the Peruvian Amazon. The true species distribution for the case study data is unknown, and thus we also undertake an extensive simulation study to evaluate model performance. We analyze the sources of error by studying the bias and variance of the models and discuss the predictive performance of each model and its ability to recover the true species distribution. The simulation study shows that, although several approaches are capable of recovering the species distribution, the choice of a modelling approach is a complex one and depends on factors such as inferential aim, model complexity, sample size, and computational resources. This study also addresses some issues in dealing with compound-imperfect observations arising from citizen-science data, and we discuss further steps needed in this research area.

Background FOF has been used in the treatment of multidrug-resistant (MDR) KP infections despite established susceptibility breakpoints. At present, agar dilution (AD) is considered the reference method for FOF while broth microdilution (BMD) is specifically recommended against despite its convenience over AD. We therefore sought to assess FOF activity against KP, along with essential and categorical agreement between AD and BMD methods to determine if BMD could be used as a reliable testing method. Methods Minimal inhibitory concentration (MIC) values were determined for a convenience collection of 69 KP isolates (59.4% MDR) from three US institutions. MIC testing was conducted in duplicate on separate days using AD and BMD methods; essential and categorical agreement were calculated using AD as the reference method. Fourteen isolates were also analyzed using high-inoculum AD (105.3-5.9 CFU/mL) similar to the BMD method. MIC values were categorized using Clinical and Laboratory Standards Institute (CLSI) interpretive criteria for Escherichia coli (≤ 64 mg/L, susceptible). ECVs were determined according to CLSI methodology. Results MIC values varied between methods, withMIC50/MIC90 values being 32/256 mg/L for AD and 128/256 mg/L for BMD. Using E. coli criteria, susceptible/intermediate/resistant rates were 82.6/2.9/14.5% (AD) and 44.9/21.7/33.3% (BMD). Essential agreement was 44.9% and categorical agreement was 60.8%. When using high-inoculum AD, MIC values were on average three-fold higher compared to standard-inoculum AD, with 10 of the 14 (71.4%) isolates brought into essential agreement with BMD. Calculated ECVs were 128 mg/L for standard-inoculum AD and 1024 mg/L for BMD. Conclusion Our collection of KP displayed high MIC values to FOF, in addition to substantial discrepancies between AD and BMD methods. Essential agreement increased with the use of high-inoculum AD testing, which better correlated with BMD results. ECV for BMD was three dilutions higher than that for standard-AD ECV. Based on these results, we recommend further investigation of BMD for FOF testing using a larger isolate collection, along with optimization of currently recommended testing methods. In light of these results, KP-specific breakpoints should also be examined. Disclosures Elizabeth B. Hirsch, PharmD, Merck (Grant/Research Support)Nabriva Therapeutics (Advisor or Review Panel member)

This essay traces a co-exploration into understanding aging, memory, and purpose through the analysis of elders stories told during varying stages of memory loss. Responding to the prompt, “What are the memories you don’t want to forget?” participants told stories of “culturally uncomfortable” identities they worried no one else prioritized remembering. As the researchers, we were faced with the struggle to continue human connection beyond vulnerable, inescapably mortal bodies. We analyze our reactions within our analysis of their stories to offer a dynamic means to make sense of data, ourselves, and shared cultural responsibility through telling and listening to personal narratives.

ObjectiveWe tested whether the presence of both child-targeted and nutrition-focused (i.e. parent-targeted) marketing cues on food packaging was associated with the nutritional content of these products.DesignWe conducted a quantitative content analysis of 403 food packages chosen randomly from the supermarket’s online portal along with all products (n 312) from the cereal aisle in a supermarket from the Southeastern USA. We examined main and interaction effects for cues on nutritional content (e.g. energy density, sugar, sodium, fibre).SettingA regional supermarket chain in the Southeastern USA.ResultsTests of main effects indicated that increased presence of nutritional cues was linked to more nutritious content (e.g. less sugar, less saturated fat, more fibre) while the increased presence of child-targeted cues was uniformly associated with less nutritious content (e.g. more sugar, less protein, less fibre). Among the interaction effects, results revealed that products with increased nutrition-focused and child-targeted cues were likely to contain significantly more sugar and less protein than other products.ConclusionsProducts that seek to engage children with their packaging in the supermarket are significantly less nutritious than foods that do not, while product packages that suggest nutritional benefits have more nutritious content. More importantly, the study provides evidence that those products which try to engage both child and parent consumers are significantly less healthy in crucial ways (e.g. more sugar, less fibre) than products that do not.

Background In the United States, interpretive criteria for FOF are established only for EC, yet those criteria are often extrapolated to KP. Recent studies have highlighted both inferior clinical outcomes after FOF treatment and difficulties in interpretation of inner colony subpopulations, the presence of which may affect clinical efficacy. We sought to compare FOF activity against EC and KP and to determine the prevalence of inner colony subpopulations following disk diffusion (DD) testing of the two species. Methods A convenience collection of 73 KP and 42 EC isolates from 3 U.S. institutions were included. Minimal inhibitory concentration (MIC) testing was performed in duplicate on separate days using agar dilution (AD) and DD as recommended by the Clinical and Laboratory Standards Institute guidelines, with application of EC susceptibility (≤ 64mg/L) breakpoints. The frequency and counts of inner colonies observed during DD testing was calculated, and colonies were subcultured for use in future studies. Results MIC50/90 values were 1/16 mg/L and 32/256 mg/L for EC and KP respectively. All EC isolates were considered susceptible and therefore categorical agreement was 100%. The majority of KP isolates were considered susceptible (83.6% with AD and 86.3% with DD) and categorical agreement between the methods was 84.9%. Inner colonies were observed during DD testing in 88.1% of EC isolates and 80.8% of KP isolates during at least one replicate, with 47.6% of EC isolates and 39.7% of KP isolates showing inner colony growth during both DD test replicates. More than 10 inner colonies were observed in 50% of EC isolates compared to 12.3% of KP isolates. Conclusion KP isolates demonstrated considerably higher FOF MIC values compared to EC, as evidenced by MIC50/90 values 4-5 dilutions higher than those for EC. The categorical agreement rate was higher among EC than KP, highlighting concerns regarding the practice of extrapolating FOF susceptibility breakpoints for EC to KP. The high frequency of inner colonies observed in DD for both species necessitates further studies to determine best practices for interpreting their relevance, fitness, and resistance in order to identify potential impacts to clinical efficacy of FOF. Disclosures Elizabeth B. Hirsch, PharmD, Merck (Grant/Research Support)Nabriva Therapeutics (Advisor or Review Panel member)

Background EC sequence type ST131 is the leading cause of extraintestinal EC infections, and accounts for most fluoroquinolone (FQ)-resistant and extended-spectrum β-lactamase (ESBL)-producing EC clinical isolates. The ST131-H30 subclone (H30) is responsible for most antimicrobial resistance within ST131; however, H30’s impact on clinical outcomes is poorly defined. We compared empiric treatment patterns and clinical outcomes of patients with bacteriuria caused by ST131 vs. non-ST131 EC, and by H30 vs. non-H30 EC strains. Methods Phylogroups, ST131, H30, and CTX-M-type β-lactamase genes were detected by PCR for 142 non-duplicate EC isolates collected prospectively from hospitalized or emergency-department-attending adults with monomicrobial bacteriuria at a Boston academic medical center (August 2013–January 2014). Clinical and microbiologic data were collected retrospectively from electronic health records. Baseline characteristics, empiric treatment, and clinical cure rates were compared between ST131 vs. non-ST131, and H30 vs. non-H30, patient cohorts. Results Of 142 patients with EC bacteriuria, most (76%) were female and elderly (mean age 65.2 ± 21.2 years). Overall, 35% of isolates were ST131, of which 80% (39/49) were H30. Compared with other isolates, H30 isolates demonstrated a higher frequency of ESBL production (33% vs. 8%; P < 0.001) and FQ resistance (90% vs. 8%; P > 0.001). Patients with H30 isolates (vs. non-H30 isolates) were older (mean 73.4 ± 13.6 vs. 62.1 ± 22.7 years; P < 0.01), had higher median (interquartile range [IQR]) APACHE II scores (10 [4] vs. 8 [9.5]; P = 0.01), more commonly had underlying complicating conditions (100% vs. 83%; P = 0.03) and received in vitro-inactive empirical treatment (26% vs. 3%; P < 0.01), and had a numerically lower clinical cure rate (84% vs. 96%; P = 0.08). In contrast, patients with ST131 vs. non-ST131 isolates had similar median [IQR] APACHE II scores (9 [5] vs. 8 [9]), frequencies of symptomatic UTI (61% vs. 70%) and underlying complicating conditions (24% vs. 19%), and clinical cure rates (87% vs. 95%). Conclusion Among patients with EC bacteriuria, the ST131-H30 subclone was associated significantly with ESBL production, FQ resistance, illness severity, host compromise, and numerically lower clinical cure rates in symptomatic UTI. Disclosures Elizabeth B. Hirsch, PharmD, Merck: Grant/Research Support, Research Grant; Nabriva Therapeutics: Advisory Board; Paratek Pharmaceuticals: Advisory Board.

Background FOF has been used clinically for the treatment of PA infections in the absence of established interpretive criteria. A recent study identified a low frequency of nonsusceptible inner colony mutants during disk diffusion (DD) testing of Escherichia coli; however, the frequency of this phenomenon in PA isolates is not well characterized. We sought to determine FOF activity against an international collection of PA isolates and the frequency of inner colony mutants observed during Etest and DD testing. Methods Minimal inhibitory concentration (MIC) values were determined for a convenience collection of 109 PA ([70/94] 64.2% MDR) isolates from 4 institutions in the United States and Australia. MIC testing was conducted in duplicate on separate days utilizing agar dilution (AD), broth microdilution (BMD), DD, and Etest as recommended per Clinical and Laboratory Standards Institute (CLSI). CLSI E.coli interpretive criteria (≤ 64 mg/L susceptible) were used for MIC interpretations. The proportion of isolates containing inner colonies was determined using DD and Etest. Inner colony mutants were subcultured and retested using BMD with comparison to the parent isolate MICs. Results FOF MICs varied widely and ranged from 1024 mg/L with MIC50/MIC90 values of 64/256 (AD), 64/512 (Etest), and 64/256 (BMD) mg/L. Using E. coli criteria, susceptible/resistant rates were: 60.5/17.4% for AD; 60.5/22.0% for Etest; 86.2/7.3% for DD; and 53.2/17.4% for BMD. Inner colonies were frequently observed in 38.5% and 35.8% of DD and Etest inhibition zones, respectively. After repeat testing, mutant MIC values ranged from 64 to > 1024 mg/L and a majority (85.9%) had MIC values ≥ 512 mg/L. Conclusion Observed MIC values of this (64% MDR) collection varied widely with MIC50/90 values commonly at or above the E. coli susceptibility breakpoint. Inner colony mutants were frequently observed and highly resistant. Whole-genome sequencing is currently underway for a subset of parent/mutant pairs to determine whether specific genetic alterations are attributed to the increased MICs. Based on these results, caution should be warranted in extrapolating E. coli breakpoints to other organisms, and treatment of PA with FOF should be further evaluated. Disclosures Elizabeth B. Hirsch, PharmD, Merck: Grant/Research Support, Research Grant; Nabriva Therapeutics: Advisory Board; Paratek Pharmaceuticals: Advisory Board.