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The design of potent indoleamine 2,3-dioxygenase 1 (IDO1) enzyme inhibitors targeting immunopathic neuroinflammation has emerged as an area of interest for the treatment of Alzheimer's disease (AD); additionally, recent findings on the clinical benefits of antibodies preventing β-amyloid (Aβ) aggregation have renewed efforts to discover small molecule anti-aggregants targeting proteopathic protein misfolding. Exploiting an endogenous tryptophan-like scaffold, we describe the design and synthesis of small-molecule inhibitors of both immunopathic and proteopathic processes, thus presenting the possibility of single therapeutics acting simultaneously on multiple AD pathogeneses. Specifically, investigations on compounds that inhibit both IDO1 (in human recombinant enzyme, transfected HEK293 cells, and interferon-γ stimulated human microglia assays) and Aβ aggregation (in thioflavin-T and biotinylated-Aβ oligomeric assays) are presented. Five compounds have been identified with high potency against both targets, identifying ( E)-3-styryl indoles as useful tool compounds for developing Alzheimer's therapeutics. Brain penetration of these compounds via passive diffusion or active transport was predicted using Blood-Brain Barrier Score and Brain Exposure Efficiency Score calculations, respectively; the effects of efflux (pgp, BCRP), and influx (OCT1, OCT2) transporters were similarly predicted. Structure–activity relationships were rationalised with molecular docking and molecular dynamics simulations, which also provide insights for future lead compound optimisation.

Background Multidrug-resistant organisms (MDROs) frequently contaminate hospital environments. We performed a multicenter, cluster-randomized, crossover trial of 2 methods for monitoring of terminal cleaning effectiveness. Methods Six intensive care units (ICUs) at 3 medical centers received both interventions sequentially, in randomized order. Ten surfaces were surveyed each in 5 rooms weekly, after terminal cleaning, with adenosine triphosphate (ATP) monitoring or an ultraviolet fluorescent marker (UV/F). Results were delivered to environmental services staff in real time with failing surfaces recleaned. We measured monthly rates of MDRO infection or colonization, including methicillin-resistant Staphylococcus aureus, Clostridioides difficile, vancomycin-resistant Enterococcus, and MDR gram-negative bacilli (MDR-GNB) during a 12-month baseline period and sequential 6-month intervention periods, separated by a 2-month washout. Primary analysis compared only the randomized intervention periods, whereas secondary analysis included the baseline. Results The ATP method was associated with a reduction in incidence rate of MDRO infection or colonization compared with the UV/F period (incidence rate ratio [IRR] 0.876; 95% confidence interval [CI], 0.807–0.951; P = .002). Including the baseline period, the ATP method was associated with reduced infection with MDROs (IRR 0.924; 95% CI, 0.855–0.998; P = .04), and MDR-GNB infection or colonization (IRR 0.856; 95% CI, 0.825–0.887; P Conclusions Intensive monitoring of ICU terminal room cleaning with an ATP modality is associated with a reduction of MDRO infection and colonization.

IntroductionThe study objective was to elucidate the relationship between social vulnerability and COVID-19 impacts in Philadelphia over a 2.5-year period, between June 2020 and December 2022.MethodsUsing publicly available COVID-19 case, test, hospitalization, and mortality data for Philadelphia (June 7, 2020-December 31, 2022) and area-level social vulnerability data, we compared the incidence, test positivity, hospitalization, and mortality rates in high and low vulnerability neighborhoods of Philadelphia, characterized as scoring above or below the national median score on the social vulnerability index. We used linear mixed effects models to test the association between social vulnerability and COVID-19 incidence, test positivity, hospitalization, and mortality rates, adjusting for time and age distribution.Results90.4% of Philadelphians (n= 1,430,153) live in neighborhoods classified as socially vulnerable, based on scoring above the national median score on the social vulnerability index. COVID-19 incidence, hospitalization, and mortality rates were significantly elevated in the more vulnerable communities, withp< 0.05,p< 0.005, andp< 0.001, respectively. The relative risks of COVID-19-related incidence, hospitalization, and death, comparing the more vulnerable neighborhoods to the less vulnerable neighborhoods, were 1.11 (95%CI: 1.10-1.12), 2.07 (95%CI: 1.93-2.20), and 2.06 (95%CI: 1.78-2.38), respectively. Thus, between June 7, 2020 and December 31, 2022, 32,573 COVID-19 cases, 9,409 hospitalizations, and 1,967 deaths would have been avoided in Philadelphia’s more vulnerable communities had they experienced the same rates of incidence, hospitalization, and death as the less vulnerable Philadelphia communities.ConclusionsThese results highlight the disparate morbidity and mortality experienced by people living in more vulnerable neighborhoods in a large US city. Importantly, our findings illustrate the importance of designing public health policies and interventions with an equity-driven approach, with greater resources and more intensive prevention strategies applied in socially vulnerable communities.

Background:The spatial and temporal extent of severe acute respiratory coronavirus virus 2 (SARS-CoV-2) environmental contamination has not been precisely defined. We sought to elucidate contamination of different surface types and how contamination changes over time.Methods:We sampled surfaces longitudinally within COVID-19 patient rooms, performed quantitative RT-PCR for the detection of SARS-CoV-2 RNA, and modeled distance, time, and severity of illness on the probability of detecting SARS-CoV-2 using a mixed-effects binomial model.Results:The probability of detecting SARS-CoV-2 RNA in a patient room did not vary with distance. However, we found that surface type predicted probability of detection, with floors and high-touch surfaces having the highest probability of detection: floors (odds ratio [OR], 67.8; 95% credible interval [CrI], 36.3–131) and high-touch elevated surfaces (OR, 7.39; 95% CrI, 4.31–13.1). Increased surface contamination was observed in room where patients required high-flow oxygen, positive airway pressure, or mechanical ventilation (OR, 1.6; 95% CrI, 1.03–2.53). The probability of elevated surface contamination decayed with prolonged hospitalization, but the probability of floor detection increased with the duration of the local pandemic wave.Conclusions:Distance from a patient’s bed did not predict SARS-CoV-2 RNA deposition in patient rooms, but surface type, severity of illness, and time from local pandemic wave predicted surface deposition.

The spread of SARS-CoV-2, like that of many other pathogens, is governed by heterogeneity. “Superspreading,” or “over-dispersion,” is an important factor in transmission, yet it is hard to quantify. Estimates from contact tracing data are prone to potential biases due to the increased likelihood of detecting large clusters of cases, and may reflect variation in contact behavior more than biological heterogeneity. In contrast, the average number of secondary infections per contact is routinely estimated from household surveys, and these studies can minimize biases by testing all members of a household. However, the models used to analyze household transmission data typically assume that infectiousness and susceptibility are the same for all individuals or vary only with predetermined traits such as age. Here we develop and apply a combined forward simulation and inference method to quantify the degree of inter-individual variation in both infectiousness and susceptibility from observations of the distribution of infections in household surveys. First, analyzing simulated data, we show our method can reliably ascertain the presence, type, and amount of these heterogeneities with data from a sufficiently large sample of households. We then analyze a collection of household studies of COVID-19 from diverse settings around the world, and find strong evidence for large heterogeneity in both the infectiousness and susceptibility of individuals. Our results also provide a framework to improve the design of studies to evaluate household interventions in the presence of realistic heterogeneity between individuals.

Enteric pathogens are exposed to a dynamic polymicrobial environment in the gastrointestinal tract(1). This microbial community has been shown to be important during infection, but there are few examples illustrating how microbial interactions can influence virulence of invading pathogens(2). Here, we show that expansion of a group of antibiotic-resistant, opportunistic pathogens in the gut, the enterococci, enhances fitness and pathogenesis of C. difficile. Through a parallel process of nutrient restriction and cross-feeding, enterococci shape the metabolic environment in the gut and reprogram C. difficile metabolism. Enterococci provide fermentable amino acids, including leucine and ornithine, which increase C. difficile fitness in the antibiotic perturbed gut. Parallel depletion of arginine by enterococci through arginine catabolism provides a metabolic cue for C. difficile that facilitates increased virulence. Evidence of microbial interaction between these two pathogenic organisms is observed in multiple mouse models of infection and C. difficile-infected patients. These findings provide mechanistic insights into the role that pathogenic microbiota have in susceptibility to and severity of C. difficile infection.

Background Ventilator-associated lower respiratory tract infection (VA-LRTI) is common among critically ill patients and has been associated with increased morbidity and mortality. In acute critical illness, respiratory microbiome disruption indices (MDIs) have been shown to predict risk for VA-LRTI, but their utility beyond the first days of critical illness is unknown. We sought to characterize how MDIs previously shown to predict VA-LRTI at initiation of mechanical ventilation change with prolonged mechanical ventilation, and if they remain associated with VA-LRTI risk. Methods We developed a cohort of 83 subjects admitted to a long-term acute care hospital due to their prolonged dependence on mechanical ventilation; performed dense, longitudinal sampling of the lower respiratory tract, collecting 1066 specimens; and characterized the lower respiratory microbiome by 16S rRNA sequencing as well as total bacterial abundance by 16S rRNA quantitative polymerase chain reaction. Results Cross-sectional MDIs, including low Shannon diversity and high total bacterial abundance, were associated with risk for VA-LRTI, but associations had wide posterior credible intervals. Persistent lower respiratory microbiome disruption showed a more robust association with VA-LRTI risk, with each day of (base e) Shannon diversity Conclusions Cross-sectional MDIs have limited ability to discriminate VA-LRTI risk during prolonged mechanical ventilation, but persistent lower respiratory tract microbiome disruption, best characterized by consecutive days with low Shannon diversity, may identify a population at high risk for infection and may help target infection-prevention interventions.

OBJECTIVE Little is known about temporal changes in nasal bacteria in granulomatosis with polyangiitis (GPA). This study was undertaken to examine longitudinal changes in the nasal microbiome in association with relapse in GPA patients. METHODS Bacterial 16S ribosomal RNA gene sequencing was performed on nasal swabs from 19 patients with GPA who were followed up longitudinally for a total of 78 visits, including 9 patients who experienced a relapse and 10 patients who remained in remission. Relative abundance of bacteria and ratios between bacteria were examined. Generalized estimating equation models were used to evaluate the association between bacterial composition and 1) disease activity and 2) levels of antineutrophil cytoplasmic antibody (ANCA) with specificity for proteinase 3 (PR3), adjusted for medication. RESULTS Corynebacterium and Staphylococcus were the most abundant bacterial genera across all nasal samples. Patients with quiescent disease maintained a stable ratio of Corynebacterium to Staphylococcus across visits. In contrast, in patients who experienced a relapse, a significantly lower ratio was observed at the visit prior to relapse, followed by a higher ratio at the time of relapse (adjusted P < 0.01). Species-level analysis identified an association between a higher abundance of nasal Corynebacterium tuberculostearicum and 1) relapse (adjusted P = 0.04) and 2) higher PR3-ANCA levels (adjusted P = 0.02). CONCLUSION In GPA, significant changes occur in the nasal microbiome over time and are associated with disease activity. The occurrence of these changes months prior to the onset of relapse supports a pathogenic role of nasal bacteria in GPA. Our results uphold existing hypotheses implicating Staphylococcus as an instigator of disease and have generated a novel finding involving Corynebacterium as a potential mediator of disease in GPA.

Mutations in the viral genome of SARS-CoV-2 can impact the performance of molecular diagnostic assays. In some cases, such as S gene target failure, the impact can serve as a unique indicator of a particular SARS-CoV-2 variant and provide a method for rapid detection. Here we describe partial ORF1ab gene target failure (pOGTF) on the cobas® SARS-CoV-2 assays, defined by a ≥2 thermocycles delay in detection of the ORF1ab gene compared to the E gene. We demonstrate that pOGTF is 97% sensitive and 99% specific for SARS-CoV-2 lineage BA.2.12.1, an emerging variant in the United States with spike L452Q and S704L mutations that may impact transmission, infectivity, and/or immune evasion. Increasing rates of pOGTF closely mirrored rates of BA.2.12.1 sequences uploaded to public databases, and, importantly increasing local rates of pOGTF also mirrored increasing overall test positivity. Use of pOGTF as a proxy for BA.2.12.1 provides faster tracking of the variant than whole-genome sequencing and can benefit laboratories without sequencing capabilities.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections have spilled over from humans to companion and wild animals since the inception of the global COVID-19 pandemic. However, whole genome sequencing data of the viral genomes that infect non-human animal species has been scant. Here, we detected and sequenced a SARS-CoV-2 delta variant (AY.3) in fecal samples from an 11-year-old domestic house cat previously exposed to an owner who tested positive for SARS-CoV-2. Molecular testing of two fecal samples collected 7 days apart yielded relatively high levels of viral RNA. Sequencing of the feline-derived viral genomes showed the two to be identical, and differing by between 4 and 14 single nucleotide polymorphisms in pairwise comparisons to human-derived lineage AY.3 sequences collected in the same geographic area and time period. However, several mutations unique to the feline samples reveal their divergence from this cohort on phylogenetic analysis. These results demonstrate continued spillover infections of emerging SARS-CoV-2 variants that threaten human and animal health, as well as highlight the importance of collecting fecal samples when testing for SARS-CoV-2 in animals. To the authors’ knowledge, this is the first published case of a SARS-CoV-2 delta variant in a domestic cat in the United States.

The severe acute respiratory coronavirus-2 (SARS-CoV-2) is the cause of the global outbreak of COVID-19. Evidence suggests that the virus is evolving to allow efficient spread through the human population, including vaccinated individuals. Here we report a study of viral variants from surveillance of the Delaware Valley, including the city of Philadelphia, and variants infecting vaccinated subjects. We sequenced and analyzed complete viral genomes from 2621 surveillance samples from March 2020 to September 2021 and compared them to genome sequences from 159 vaccine breakthroughs. In the early spring of 2020, all detected variants were of the B.1 and closely related lineages. A mixture of lineages followed, notably including B.1.243 followed by B.1.1.7 (alpha), with other lineages present at lower levels. Later isolations were dominated by B.1.617.2 (delta) and other delta lineages; delta was the exclusive variant present by the last time sampled. To investigate whether any variants appeared preferentially in vaccine breakthroughs, we devised a model based on Bayesian autoregressive moving average logistic multinomial regression to allow rigorous comparison. This revealed that B.1.617.2 (delta) showed three-fold enrichment in vaccine breakthrough cases (odds ratio of 3; 95% credible interval 0.89-11). Viral point substitutions could also be associated with vaccine breakthroughs, notably the N501Y substitution found in the alpha, beta and gamma variants (odds ratio 2.04; 95% credible interval of 1.25-3.18). This study thus provides a detailed picture of viral evolution in the Delaware Valley and a geographically matched analysis of vaccine breakthroughs; it also introduces a rigorous statistical approach to interrogating enrichment of viral variants.ImportanceSARS-CoV-2 vaccination is highly effective at reducing viral infection, hospitalization and death. However, vaccine breakthrough infections have been widely observed, raising the question of whether particular viral variants or viral mutations are associated with breakthrough. Here we report analysis of 2621 surveillance isolates from people diagnosed with COVID-19 in the Delaware Valley in South Eastern Pennsylvania, allowing rigorous comparison to 159 vaccine breakthrough case specimens. Our best estimate is a three-fold enrichment for some lineages of delta among breakthroughs, and enrichment of a notable spike substitution, N501Y. We introduce statistical methods that should be widely useful for evaluating vaccine breakthroughs and other viral phenotypes.

Background:Multidrug-resistant organisms (MDROs) colonizing the healthcare environment have been shown to contribute to risk for healthcare-associated infections (HAIs), with adverse effects on patient morbidity and mortality. We sought to determine how bacterial contamination and persistent MDRO colonization of the healthcare environment are related to the position of patients and wastewater sites.Methods:We performed a prospective cohort study, enrolling 51 hospital rooms at the time of admitting a patient with an eligible MDRO in the prior 30 days. We performed systematic sampling and MDRO culture of rooms, as well as 16S rRNA sequencing to define the environmental microbiome in a subset of samples.Results:The probability of detecting resistant gram-negative organisms, including Enterobacterales, Acinetobacter spp, and Pseudomonas spp, increased with distance from the patient. In contrast, Clostridioides difficile and methicillin-resistant Staphylococcus aureus were more likely to be detected close to the patient. Resistant Pseudomonas spp and S. aureus were enriched in these hot spots despite broad deposition of 16S rRNA gene sequences assigned to the same genera, suggesting modifiable factors that permit the persistence of these MDROs.Conclusions:MDRO hot spots can be defined by distance from the patient and from wastewater reservoirs. Evaluating how MDROs are enriched relative to bacterial DNA deposition helps to identify healthcare micro-environments and suggests how targeted environmental cleaning or design approaches could prevent MDRO persistence and reduce infection risk.

Comparative genomics has enabled the identification of genes that potentially evolved de novo from non-coding sequences. Many such genes are expressed in male reproductive tissues, but their functions remain poorly understood. To address this, we conducted a functional genetic screen of over 40 putative de novo genes with testis-enriched expression in Drosophila melanogaster and identified one gene, atlas, required for male fertility. Detailed genetic and cytological analyses showed that atlas is required for proper chromatin condensation during the final stages of spermatogenesis. Atlas protein is expressed in spermatid nuclei and facilitates the transition from histone- to protamine-based chromatin packaging. Complementary evolutionary analyses revealed the complex evolutionary history of atlas. The protein-coding portion of the gene likely arose at the base of the Drosophila genus on the X chromosome but was unlikely to be essential, as it was then lost in several independent lineages. Within the last ∼15 million years, however, the gene moved to an autosome, where it fused with a conserved non-coding RNA and evolved a non-redundant role in male fertility. Altogether, this study provides insight into the integration of novel genes into biological processes, the links between genomic innovation and functional evolution, and the genetic control of a fundamental developmental process, gametogenesis.Author SummaryGenomes are in flux, as genes are constantly added and lost throughout evolution. New genes were once thought to arise almost exclusively via the modification or duplication of existing genes. Recently, however, interest has grown in alternative modes of new gene origination, such as de novo evolution from genetic material that previously did not encode proteins. Many de novo genes are expressed in male reproductive tissues, but their significance for fertility is not well understood. We screened likely de novo genes expressed in the Drosophila testis for reproductive roles and found one gene, atlas, essential for male fertility. We leveraged genetic and cell biological experiments to investigate roles for Atlas protein in reproduction and found that it is required during sperm development for proper packaging of DNA in the sperm nucleus. Evolutionary analyses of this gene revealed a complicated history, including loss in some lineages, movement between chromosomes, and fusion with a non-protein-coding gene. Studying both the functions and evolutionary histories of new proteins illustrates how they might evolve critical roles in biological processes despite their relative novelty. Furthermore, the study of atlas identifies an essential genetic player in the fly testis, an important model system for understanding how gametes are produced.

BackgroundCulture-based studies, which focus on individual organisms, have implicated stethoscopes as potential vectors of nosocomial bacterial transmission. However, the full bacterial communities that contaminate in-use stethoscopes have not been investigated.MethodsWe used bacterial 16S rRNA gene deep-sequencing, analysis, and quantification to profile entire bacterial populations on stethoscopes in use in an intensive care unit (ICU), including practitioner stethoscopes, individual-use patient-room stethoscopes, and clean unused individual-use stethoscopes. Two additional sets of practitioner stethoscopes were sampled before and after cleaning using standardized or practitioner-preferred methods.ResultsBacterial contamination levels were highest on practitioner stethoscopes, followed by patient-room stethoscopes, whereas clean stethoscopes were indistinguishable from background controls. Bacterial communities on stethoscopes were complex, and community analysis by weighted UniFrac showed that physician and patient-room stethoscopes were indistinguishable and significantly different from clean stethoscopes and background controls. Genera relevant to healthcare-associated infections (HAIs) were common on practitioner stethoscopes, among which Staphylococcus was ubiquitous and had the highest relative abundance (6.8%–14% of contaminating bacterial sequences). Other HAI-related genera were also widespread although lower in abundance. Cleaning of practitioner stethoscopes resulted in a significant reduction in bacterial contamination levels, but these levels reached those of clean stethoscopes in only a few cases with either standardized or practitioner-preferred methods, and bacterial community composition did not significantly change.ConclusionsStethoscopes used in an ICU carry bacterial DNA reflecting complex microbial communities that include nosocomially important taxa. Commonly used cleaning practices reduce contamination but are only partially successful at modifying or eliminating these communities.

Background The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reverse-transcription polymerase chain reaction (RT-PCR) cycle threshold (Ct) has been used to estimate quantitative viral load, with the goal of targeting isolation precautions for individuals with coronavirus disease 2019 (COVID-19) and guiding public health interventions. However, variability in specimen quality can alter the Ct values obtained from SARS-CoV-2 clinical assays. We sought to define how variable nasopharyngeal (NP) swab quality impacts clinical SARS-CoV-2 test sensitivity. Methods We performed amplification of a human gene target (β-actin) in parallel with a clinical RT-PCR targeting the SARS-CoV-2 ORF1ab gene for 1282 NP specimens collected from patients with clinical concern for COVID-19. We evaluated the relationship between NP specimen quality, characterized by late Ct values for the human gene target β-actin Ct, and the probability of SARS-CoV-2 detection via logistic regression, as well as the linear relationship between SARS-CoV-2 and β-actin Ct. Results Low-quality NP swabs are less likely to detect SARS-CoV-2 (odds ratio, 0.607 [95% credible interval {CrI}, .487–.753]). We observed a positive linear relationship between SARS-CoV-2 and β-actin Ct values (slope, 0.181 [95% CrI, .097–.264]), consistent with a reduction in detection of 0.181 cycles for each additional cycle of the β-actin target. COVID-19 disease severity was not associated with β-actin Ct values. Conclusions Variability in NP specimen quality significantly impacts the performance of clinical SARS-CoV-2 assays, and caution should be taken when interpreting quantitative SARS-CoV-2 Ct results. If unrecognized, low-quality NP specimens, which are characterized by a low level of amplifiable human DNA target, may limit the successful application of SARS-CoV-2 Ct values to direct infection control and public health interventions.

Objective:Tracheal intubation and mechanical ventilation provide essential support for patients with respiratory failure, but the course of mechanical ventilation may be complicated by adverse ventilator-associated events (VAEs), which may or may not be associated with infection. We sought to understand how the frequency of subglottic suction, an indicator of the quantity of sputum produced by ventilated patients, relates to the onset of all VAEs and infection-associated VAEs.Design:We performed a case-crossover study including 87 patients with VAEs, and we evaluated 848 days in the pre-VAE period at risk for a VAE.Setting and participants:Critically ill patients were recruited from the medical intensive care unit of an academic medical center.Methods:We used the number of as-needed subglottic suctioning events performed per calendar day to quantify sputum production, and we compared the immediate pre-VAE period to the preceding period. We used CDC surveillance definitions for VAE and to categorize whether events were infection associated or not.Results:Sputum quantity measured by subglottic suction frequency is greater in the period immediately prior to VAE than in the preceding period. However, it does not discriminate well between infection-associated VAEs and VAEs without associated infection.Conclusions:Subglottic suction frequency may serve as a valuable marker of sputum quantity, and it is associated with risk of a VAE. However, our results require validation in a broader population of mechanically ventilated patients and intensive care settings.

BackgroundThe SARS-CoV-2 reverse-transcription polymerase chain reaction (RT-PCR) cycle of threshold (Ct) has been used to estimate quantitative viral load, with the goal of targeting isolation precautions for individuals with COVID-19 and guiding public health interventions. However, variability in specimen quality can alter the Ct values obtained from SARS-CoV-2 clinical assays. We sought to define how variable nasopharyngeal (NP) swab quality impacts clinical SARS-CoV-2 test sensitivity.MethodsWe performed amplification of a human gene target (β-actin) in parallel with a clinical RT-PCR targeting the SARS-CoV-2 ORF1ab gene for 1311 NP specimens collected from patients with clinical concern for COVID-19. We evaluated the relationship between NP specimen quality, characterized by high Ct values for the human gene target β-actin Ct, and the probability of SARS-CoV-2 detection via logistic regression, as well as the linear relationship between SARS-CoV-2 and β-actin Ct.ResultsLow quality NP swabs are less likely to detect SARS-CoV-2 (odds ratio 0.654, 95%CI 0.523 to 0.802). We observed a positive linear relationship between SARS-CoV-2 and β-actin Ct values (slope 0.169, 95%CI 0.092 to 0.247). COVID-19 disease severity was not associated with β-actin Ct values.ConclusionsVariability in NP specimen quality accounts for significant differences in the sensitivity of clinical SARS-CoV-2 assays. If unrecognized, low quality NP specimens, which are characterized by a low level of amplifiable human DNA target, may limit the application of SARS-CoV-2 Ct values to direct infection control and public health interventions.

Edhazardia aedis is a microsporidian parasite of Aedes aegypti mosquitoes, a disease vector that transmits multiple arboviruses which cause millions of disease cases each year. E. aedis causes mortality and reduced reproductive fitness in the mosquito vector and has been explored for its potential as a biocontrol agent. The protocol we present for culturing E. aedis is based on its natural infection cycle, which involves both horizontal and vertical transmission at different life stages of the mosquito host. Ae. aegypti mosquitoes are exposed to spores in the larval stage. These infected larvae then mature into adults and transmit the parasite vertically to their offspring. Infected offspring are then used as a source of spores for future horizontal transmission. Culturing E. aedis can be challenging to the uninitiated given the complexities of the parasite's life cycle, and this protocol provides detailed guidance and visual aids for clarification.

Edhazardia aedis is a microsporidian parasite of Aedes aegypti mosquitoes, a disease vector that transmits multiple arboviruses which cause millions of disease cases each year. E. aedis causes mortality and reduced reproductive fitness in the mosquito vector and has been explored for its potential as a biocontrol agent. The protocol we present for culturing E. aedis is based on its natural infection cycle, which involves both horizontal and vertical transmission at different life stages of the mosquito host. Ae. aegypti mosquitoes are exposed to spores in the larval stage. These infected larvae then mature into adults and transmit the parasite vertically to their offspring. Infected offspring are then used as a source of spores for future horizontal transmission. Culturing E. aedis can be challenging to the uninitiated given the complexities of the parasite's life cycle, and this protocol provides detailed guidance and visual aids for clarification.

Background Clostridioides difficile infection (CDI) is the leading cause of antibiotic-associated and health care–associated diarrhea in humans. Recurrent CDI (R-CDI) occurs in ~20%–30% of patients with CDI and results in increased morbidity, mortality, and hospital costs. Genomic analyses have shown overlap of C. difficile isolates from animals and people, suggesting that a zoonotic reservoir may contribute to recurrence. The objective of this study was to determine whether pet ownership is a risk factor for recurrence of CDI. Methods We conducted a case–control study among patients with recurrent CDI (cases; n = 86) and patients with nonrecurrent CDI (controls; n = 146). Multivariable logistic regression modeling was used to determine the association between recurrence of CDI and pet ownership while accounting for patient-level risk factors. Results Pet ownership was not significantly associated with recurrence of CDI (odds ratio [OR], 1.02; 95% confidence interval [CI], 0.38–2.72; P = 0.965) among all patients (n = 232). However, among the subset of patients with community-associated or community-onset health care facility–acquired CDI (n = 127), increasing contact with pets was increasingly protective against recurrence: for every point increase in a pet contact score (out of 7 possible points), the odds of recurrence decreased by 14% (OR, 0.86; 95% CI, 0.74–1.00; P = 0.051). Conclusions Close interactions with pets appear protective against the recurrence of community-acquired CDI. A potential mechanism may involve beneficial contributions to the microbiota of pet owners afflicted with CDI, as has been observed for other conditions such as atopy, obesity, and food allergies. However, more research is needed to understand the interactions between pets, owners, and their microbiota., The recurrence of Clostridioides difficile infection, the leading cause of health-care associated diarrhea, results in increased morbidity, mortality, and hospital costs. Close contact with pets appears to be protective against recurrence in patients with community-acquired or -onset C. difficile infection.

Objectives Sepsis is associated with high early and total in-hospital mortality. Despite recent revisions in the diagnostic criteria for sepsis that sought to improve predictive validity for mortality, it remains difficult to identify patients at greatest risk of death. We compared the utility of nine biomarkers to predict mortality in subjects with clinically suspected bacterial sepsis. Design Cohort study. Setting The medical and surgical ICUs at an academic medical center. Subjects We enrolled 139 subjects who met two or more systemic inflammatory response syndrome (systemic inflammatory response syndrome) criteria and received new broad-spectrum antibacterial therapy. Interventions We assayed nine biomarkers (α-2 macroglobulin, C-reactive protein, ferritin, fibrinogen, haptoglobin, procalcitonin, serum amyloid A, serum amyloid P, and tissue plasminogen activator) at onset of suspected sepsis and 24, 48, and 72 hours thereafter. We compared biomarkers between groups based on both 14-day and total in-hospital mortality and evaluated the predictive validity of single and paired biomarkers via area under the receiver operating characteristic curve. Measurements and main results Fourteen-day mortality was 12.9%, and total in-hospital mortality was 29.5%. Serum amyloid P was significantly lower (4/4 timepoints) and tissue plasminogen activator significantly higher (3/4 timepoints) in the 14-day mortality group, and the same pattern held for total in-hospital mortality (Wilcoxon p ≤ 0.046 for all timepoints). Serum amyloid P and tissue plasminogen activator demonstrated the best individual predictive performance for mortality, and combinations of biomarkers including serum amyloid P and tissue plasminogen activator achieved greater predictive performance (area under the receiver operating characteristic curve > 0.76 for 14-d and 0.74 for total mortality). Conclusions Combined biomarkers predict risk for 14-day and total mortality among subjects with suspected sepsis. Serum amyloid P and tissue plasminogen activator demonstrated the best discriminatory ability in this cohort.

Background: Clinically diagnosed ventilator-associated pneumonia (VAP) is common in the long-term acute-care hospital (LTACH) setting and may contribute to adverse ventilator-associated events (VAEs). Pseudomonas aeruginosa is a common causative organism of VAP. We evaluated the impact of respiratory P. aeruginosa colonization and bacterial community dominance, both diagnosed and undiagnosed, on subsequent P. aeruginosa VAP and VAE events during long-term acute care. Methods: We enrolled 83 patients on LTACH admission for ventilator weaning, performed longitudinal sampling of endotracheal aspirates followed by 16S rRNA gene sequencing (Illumina HiSeq), and bacterial community profiling (QIIME2). Statistical analysis was performed with R and Stan; mixed-effects models were fit to relate the abundance of respiratory Psa on admission to clinically diagnosed VAP and VAE events. Results: Of the 83 patients included, 12 were diagnosed with P. aeruginosa pneumonia during the 14 days prior to LTACH admission (known P. aeruginosa), and 22 additional patients received anti–P. aeruginosa antibiotics within 48 hours of admission (suspected P. aeruginosa); 49 patients had no known or suspected P. aeruginosa (unknown P. aeruginosa). Among the known P. aeruginosa group, all 12 patients had P. aeruginosa detectable by 16S sequencing, with elevated admission P. aeruginosa proportional abundance (median, 0.97; IQR, 0.33–1). Among the suspected P. aeruginosa group, all 22 patients had P. aeruginosa detectable by 16S sequencing, with a wide range of admission P. aeruginosa proportional abundance (median, 0.0088; IQR, 0.00012–0.31). Of the 49 patients in the unknown group, 47 also had detectable respiratory Psa, and many had high P. aeruginosa proportional abundance at admission (median, 0.014; IQR, 0.00025–0.52). Incident P. aeruginosa VAP was observed within 30 days in 4 of the known P. aeruginosa patients (33.3%), 5 of the suspected P. aeruginosa patients (22.7%), and 8 of the unknown P. aeruginosa patients (16.3%). VAE was observed within 30 days in 1 of the known P. aeruginosa patients (8.3%), 2 of the suspected P. aeruginosa patients (9.1%), and 1 of the unknown P. aeruginosa patients (2%). Admission P. aeruginosa abundance was positively associated with VAP and VAE risk in all groups, but the association only achieved statistical significance in the unknown group (type S error Conclusions: We identified a high prevalence of unrecognized respiratory P. aeruginosa colonization among patients admitted to LTACH for weaning from mechanical ventilation. The admission P. aeruginosa proportional abundance was strongly associated with increased risk of incident P. aeruginosa VAP among these patients.Funding: NoneDisclosures: None

Background Identifying risk factors for environmental contamination with multidrug-resistant organisms (MDROs) is essential to prioritize methods for prevention of hospital transmission. Methods Patients admitted to an ICU with an MDRO detected on clinical culture in the prior 30 days were enrolled. Patients (4 body sites) and high-touch objects (HTO) (3 composite sites) in ICU rooms were sampled. Environmental transmission was defined by shared MDRO species cultured on patient and HTO cultures obtained on multiple time points during the patient’s stay. Risk factors for environmental transmission were identified with logistic regression. Results Forty-five patients were included (median 2 days of longitudinal sampling [IQR 1–4 days]). Enrollment anatomic cultures included extended-spectrum beta-lactamase-producing Enterobacterales (ESBLE) (n=12, 27%), carbapenem-resistant organisms (CRO) (n=4, 9%), methicillin-resistant S.aureus (MRSA) (n=11, 24%), vancomycin-resistant Enterococci (VRE) (n=4, 9%), and C.difficile (CDIFF) (n=14, 31%). Patient colonization during serial sampling was common with CRO (n=21, 47%), ESBLE (n=16, 36%), and VRE (n=16, 36%) and less so with MRSA (n=7, 16%) and CDIFF (n=5, 11%). Detection of MDROs on environmental surfaces was also common with identification of CRO in 47% of patient rooms (n=21) and ESBLE in 29% (n=13); MRSA (n=2, 4%), VRE (n=9, 20%), and CDIFF (n=3, 7%) were rarer. Patient to environment transmission was observed in 40% of rooms (n=18). Thirteen (29%) rooms had foreign MDRO contamination (i.e., one not detected on a body culture), most (n=10) with CRO. Environmental MDROs were most common in bathroom/sinks (n=22), followed by surfaces near the patient (n=10), and least common surfaces often touched by staff within the room (n=6). On multivariable logistic regression, naïve to clustering by patient, recent receipt of a proton pump inhibitor (OR 2.35, 95% CI 1.00 – 5.52, P=0.049) and presence of one or more wounds (OR 2.56, 95% CI 1.05 – 6.26, P=0.038) were significantly associated with environmental transmission (OR 1.56, 95% CI 1.01 – 2.43, P=0.046) (Table 1). Conclusion MDRO contamination of patient rooms is common with detection of organisms attributed to, and foreign to, the occupant. Disclosures Michael Z. David, MD PhD, GSK (Consultant)

Background We evaluated the differential impact of levofloxacin administered for the prophylaxis of bloodstream infections compared with broad-spectrum beta-lactam (BSBL) antibiotics used for the treatment of neutropenic fever on the gut microbiome in patients with hematologic malignancy. Methods Stool specimens were collected from patients admitted for chemotherapy or stem cell transplant in the setting of the evaluation of diarrhea from February 2017 until November 2017. Microbiome characteristics were compared among those exposed to levofloxacin prophylaxis vs those who received BSBL antibiotics. Results Sixty patients were included, most with acute myeloid leukemia (42%) or multiple myeloma (37%). The gut microbiome of patients with BSBL exposure had significantly reduced Shannon’s alpha diversity compared with those without (median [interquartile range {IQR}], 3.28 [1.73 to 3.71] vs 3.73 [3.14 to 4.31]; P = .01). However, those with levofloxacin exposure had increased alpha diversity compared with those without (median [IQR], 3.83 [3.32 to 4.36] vs 3.32 [2.35 to 4.02]; P = .03). Levofloxacin exposure was also associated with a trend toward lower risk of dominance of non-Bacteroidetes genera compared with those without levofloxacin exposure (3 [14%] vs 15 [38%]; P = .051). Conclusions The impact of antibiotics on the gut microbiome varies by class, and levofloxacin may disrupt the gut microbiome less than BSBLs in this patient population.

In people, colonization withClostridium difficile, the leading cause of antibiotic-associated diarrhea, has been shown to be associated with distinct gut microbial features, including reduced bacterial community diversity and depletion of key taxa. In dogs, the gut microbiome features that defineC. difficilecolonization are less well understood. We sought to define the gut microbiome features associated withC. difficilecolonization in puppies, a population where the prevalence ofC. difficilehas been shown to be elevated, and to define the effect of puppy age and litter upon these features andC. difficilerisk. We collected fecal samples from weaned (n=27) and unweaned (n=74) puppies from 13 litters and analyzed the effects of colonization status, age and litter on microbial diversity using linear mixed effects models.Colonization withC. difficilewas significantly associated with younger age, and colonized puppies had significantly decreased bacterial community diversity and differentially abundant taxa compared to non-colonized puppies, even when adjusting for age.C. difficilecolonization remained associated with decreased bacterial community diversity, but the association did not reach statistical significance in a mixed effects model incorporating litter as a random effect.Even though litter explained a greater proportion (67%) of the variability in microbial diversity than colonization status, we nevertheless observed heterogeneity in gut microbial community diversity and colonization status within more than half of the litters, suggesting that the gut microbiome contributes to colonization resistance againstC. difficile. The colonization of puppies withC. difficilehas important implications for the potential zoonotic transfer of this organism to people. The identified associations point to mechanisms by whichC. difficilecolonization may be reduced.

Background Patients admitted to long-term acute care hospital (LTACH) for ventilator weaning are at high risk for ventilator-associated pneumonia, which may contribute to adverse ventilator-associated events (VAE). Staphylococcus aureus (Sa) is a common cause of VAP. We sought to evaluate the impact of respiratory Sa colonization and bacterial community dominance on subsequent Sa VAP and VAE during long-term acute care. Methods We enrolled 83 subjects dependent on mechanical ventilation at LTACH admission, collected endotracheal aspirates, performed 16S rRNA gene sequencing (Illumina HiSeq) and bacterial community profiling (QIIME2). Statistical analysis was performed with R and Stan; mixed effects models were fit to relate the abundance of respiratory Sa on admission to clinically-diagnosed VAP and VAE. Results Of the 83 subjects, 8 were diagnosed with Sa pneumonia during the 14 days prior to LTACH admission (“Known Sa”), and 17 additional subjects received anti- Sa antibiotics within 48 hours of admission (“Suspected Sa”); 58 subjects had no known or suspected Sa (“Unknown Sa”). Among the Known Sa group, all 8 had Sa detectable by 16S sequencing, with elevated admission Sa proportional abundance (median 0.36; range 0.0013 - 1). Among the Suspected Sa group, only 7 had Sa detectable by 16S sequencing, with a wide range of admission Sa proportional abundance (median 0; range 0 - 0.96). 25 of 58 subjects in the Unknown Sa group also had detectable respiratory Sa, and a wide range of Sa proportional abundance at admission (median 0; range 0 - 0.93). Incident Sa VAP was observed within 30 days among 2 (25%) of the Known Sa subjects, 0 (0%) of the Suspected Sa subjects, and 3 (5.17%) of the Unknown Sa subjects. VAE was observed within 30 days among 0 (0%) of the Known Sa subjects, 3 (18%) of the Suspected Sa subjects, and 1 (1.7%) of the Unknown Sa subjects. Admission Sa abundance was positively associated with 30-day VAP risk in the Suspected Sa (type S error < 0.001) and Unknown Sa (type S error < 0.001) groups. Conclusion Among patients admitted to LTACH for weaning for mechanical ventilation, we observed a high prevalence of respiratory Sa colonization. Respiratory Sa abundance was associated with risk of incident Sa VAP, particularly among subjects without recognized Sa colonization. Disclosures All Authors: No reported disclosures

Motivation: The variation in community composition between microbiome samples, termed beta diversity, can be measured by pairwise distance based on either presence–absence or quantitative species abundance data. PERMANOVA, a permutation-based extension of multivariate analysis of variance to a matrix of pairwise distances, partitions within-group and between-group distances to permit assessment of the effect of an exposure or intervention (grouping factor) upon the sampled microbiome. Within-group distance and exposure/intervention effect size must be accurately modeled to estimate statistical power for a microbiome study that will be analyzed with pairwise distances and PERMANOVA. Results: We present a framework for PERMANOVA power estimation tailored to marker-gene microbiome studies that will be analyzed by pairwise distances, which includes: (i) a novel method for distance matrix simulation that permits modeling of within-group pairwise distances according to pre-specified population parameters; (ii) a method to incorporate effects of different sizes within the simulated distance matrix; (iii) a simulation-based method for estimating PERMANOVA power from simulated distance matrices; and (iv) an R statistical software package that implements the above. Matrices of pairwise distances can be efficiently simulated to satisfy the triangle inequality and incorporate group-level effects, which are quantified by the adjusted coefficient of determination, omega-squared (ω2). From simulated distance matrices, available PERMANOVA power or necessary sample size can be estimated for a planned microbiome study. Availability and implementation: http://github.com/brendankelly/micropower. Contact: brendank@mail.med.upenn.edu or hongzhe@upenn.edu

A substantial proportion of Clostridium difficile infection (CDI) cases recur after completion of antibiotic therapy, and antibiotic cure rates diminish with each recurrence of CDI. Fecal microbiota transplantation (FMT) is an effective therapy for recurrent FMT, which otherwise requires prolonged or indefinite antibiotic treatment. FMT is performed by introducing the fecal microbial community obtained from a healthy donor or pool of donors into the stomach, small intestine, or colon of a patient with CDI. Multiple clinical trials support the usefulness of FMT in treating recurrent CDI, and CDI treatment guidelines now include consideration of FMT at the third CDI recurrence. However, there remain challenges to incorporating FMT into clinical practice. First, methods of fecal bacterial community processing vary, as do methods of FMT administration. Second, the optimal dosing strategy and expected benefit of FMT for refractory CDI, particularly for severe and severe complicated cases, are uncertain. Third, the US Food and Drug Administration (FDA) considers FMT an investigational treatment. Fourth, insurance reimbursement for FMT usually falls short of FMT administration costs. In the setting of rising C difficile incidence and growing evidence for FMT efficacy, the demand for FMT has increased. However, uncertainty surrounding optimal FMT preparation and administration methods, FDA oversight, and insurance reimbursement presently limits the clinical practice of FMT.

Brain imaging genetics intends to uncover associations between genetic markers and neuroimaging quantitative traits. Sparse canonical correlation analysis (SCCA) can discover bi-multivariate associations and select relevant features, and is becoming popular in imaging genetic studies. The L1-norm function is not only convex, but also singular at the origin, which is a necessary condition for sparsity. Thus most SCCA methods impose $${\ell }_{{\bf{1}}}$$ ℓ 1 -norm onto the individual feature or the structure level of features to pursuit corresponding sparsity. However, the $${\ell }_{{\bf{1}}}$$ ℓ 1 -norm penalty over-penalizes large coefficients and may incurs estimation bias. A number of non-convex penalties are proposed to reduce the estimation bias in regression tasks. But using them in SCCA remains largely unexplored. In this paper, we design a unified non-convex SCCA model, based on seven non-convex functions, for unbiased estimation and stable feature selection simultaneously. We also propose an efficient optimization algorithm. The proposed method obtains both higher correlation coefficients and better canonical loading patterns. Specifically, these SCCA methods with non-convex penalties discover a strong association between the APOE e4 rs429358 SNP and the hippocampus region of the brain. They both are Alzheimer’s disease related biomarkers, indicating the potential and power of the non-convex methods in brain imaging genetics.

Background Emergency Departments (EDs) are important sites for HIV testing. However, there is little guidance on how best to implement HIV testing in the ED. The purpose of this study was to evaluate HIV screening practices of high-risk individuals presenting to an ED in the absence (ED1) and in the presence (ED2) of an established HIV testing program within the same academic hospital. Methods We performed a retrospective chart review of all individuals 18 years or older presenting to either ED between January 1, 2016 and December 31, 2018. High-risk of HIV infection was determined by receipt of bacterial sexually transmitted infection (STI) testing for Neisseria gonorrhoeae or Chlamydia trachomatis. The primary outcome was receipt of any HIV test in the ED. Overall proportions of patients tested for HIV at the same time of STI testing were compared between sites by chi-square test. Predictors of HIV testing were analyzed by logistic regression. Results During the study period, 7,956 individuals received STI testing at ED1 and 10,815 received STI testing at ED2. The majority of individuals receiving STI testing at both sites were female, 81.2% at ED1 and 66.4% at ED2 (P Conclusion Overall, the presence of an HIV testing program in the ED significantly increased the probability that individuals would receive an HIV test at the time of bacterial STI testing and mitigated disparities in care. The results of this study will help guide ongoing interventions to improve HIV screening among high-risk individuals in the emergency department. Disclosures All authors: No reported disclosures.

Background Reduced gastrointestinal tract bacterial community diversity has been associated with increased risk for healthcare-associated infections, including Clostridium difficile infection. We sought to develop a model for concomitant change in bacterial community diversity at gastrointestinal and respiratory tract sites, drawing upon a recently completed cohort study of 92 subjects recruited from a long-term acute care hospital (LTACH) for dense longitudinal oral, endotracheal aspirate (ET), and stool specimen collection. Methods We evaluated the first 30 subjects enrolled from the LTACH cohort, for whom complete antibiotic administration data and 16S rRNA gene (V1–V2 amplicon) sequencing data were available. Sequencing was performed via the Illumina HiSeq platform; operational taxonomic units (OTUs) were formed and taxonomy assigned (GreenGenes 13.8) via the QIIME 1.9.1 pipeline. Generalized linear mixed effects models were fit using R (3.5.0), Stan (2.1.7), via the “rstan” and “rethinking” packages. Results We evaluated 472 subject-days of study enrollment across the 30 subjects (median 15 days/subject). ET specimens were available for all subject-days; oral and stool for 357 and 177 subject-days, respectively. We modeled daily change in Shannon diversity across oral, ET, and stool specimens, parameterized with daily exposure to cefepime, piperacillin–tazobactam, meropenem, IV vancomycin, and oral vancomycin. All parameters fit with Rhat value lower than 1.1. Absent antibiotic exposure on the previous day, the daily change in Shannon diversity at all sites was near zero. The largest observed effect was oral vancomycin on stool (daily delta Shannon: −0.6, 95% CI: −1.38 to 0.09). All estimated effects for intravenous antibiotics on the stool, and for all antibiotics at other sites were smaller. Conclusion Small daily changes in bacterial community diversity were attributable to individual antibiotics, but all 95% certainty intervals crossed zero in this pilot study. Further work will focus on modeling specific taxonomic changes attributable to individual antibiotics and antibiotic interactions. Disclosures All authors: No reported disclosures.

Background Lower respiratory tract infection (LRTI) is a major contributor to respiratory failure requiring intubation and mechanical ventilation. LRTI also occurs during mechanical ventilation, increasing the morbidity and mortality of intubated patients. We sought to understand the dynamics of respiratory tract microbiota following intubation and the relationship between microbial community structure and infection. Results We enrolled a cohort of 15 subjects with respiratory failure requiring intubation and mechanical ventilation from the medical intensive care unit at an academic medical center. Oropharyngeal (OP) and deep endotracheal (ET) secretions were sampled within 24 h of intubation and every 48–72 h thereafter. Bacterial community profiling was carried out by purifying DNA, PCR amplification of 16S ribosomal RNA (rRNA) gene sequences, deep sequencing, and bioinformatic community analysis. We compared enrolled subjects to a cohort of healthy subjects who had lower respiratory tract sampling by bronchoscopy. In contrast to the diverse upper respiratory tract and lower respiratory tract microbiota found in healthy controls, critically ill subjects had lower initial diversity at both sites. Diversity further diminished over time on the ventilator. In several subjects, the bacterial community was dominated by a single taxon over multiple time points. The clinical diagnosis of LRTI ascertained by chart review correlated with low community diversity and dominance of a single taxon. Dominant taxa matched clinical bacterial cultures where cultures were obtained and positive. In several cases, dominant taxa included bacteria not detected by culture, including Ureaplasma parvum and Enterococcus faecalis. Conclusions Longitudinal analysis of respiratory tract microbiota in critically ill patients provides insight into the pathogenesis and diagnosis of LRTI. 16S rRNA gene sequencing of endotracheal aspirate samples holds promise for expanded pathogen identification. Electronic supplementary material The online version of this article (doi:10.1186/s40168-016-0151-8) contains supplementary material, which is available to authorized users.

International audience; The fatty acid synthesis type II pathway has received considerable interest as a candidate therapeutic target in Plasmodium falciparum asexual blood-stage infections. This apicoplast-resident pathway, distinct from the mammalian type I process, includes FabI. Here, we report synthetic chemistry and transfection studies concluding that Plasmodium FabI is not the target of the antimalarial activity of triclosan, an inhibitor of bacterial FabI. Disruption of fabI in P. falciparum or the rodent parasite P. berghei does not impede blood-stage growth. In contrast, mosquito-derived, FabI-deficient P. berghei sporozoites are markedly less infective for mice and typically fail to complete liver-stage development in vitro. This defect is characterized by an inability to form intrahepatic merosomes that normally initiate blood-stage infections. These data illuminate key differences between liver- and blood-stage parasites in their requirements for host versus de novo synthesized fatty acids, and create new prospects for stage-specific antimalarial interventions.

Among surgical intensive care unit (SICU) patients, it is difficult to distinguish bacterial sepsis from other causes of systemic inflammatory response syndrome (SIRS). Biomarkers have proven useful to identify the presence of bacterial infection. We enrolled a prospective cohort of 69 SICU patients with suspected sepsis and assayed the concentrations of 9 biomarkers (α-2 macroglobulin [A2M], C-reactive protein, ferritin, fibrinogen, haptoglobin, procalcitonin [PCT], serum amyloid A, serum amyloid P, and tissue plasminogen activator) at baseline, 24, 48, and 72hours. Forty-two patients (61%) had bacterial sepsis by chart review. A2M concentrations were significantly lower, and PCT concentrations were significantly higher in subjects with bacterial sepsis at 3 of 4 time points. Using optimal cutoff values, the combination of baseline A2M and 72-hour PCT achieved a negative predictive value of 75% (95% confidence interval, 54-96%). The combination of A2M and PCT discriminated bacterial sepsis from other SIRS among SICU patients with suspected sepsis.

In many studies of HIV replication, it is useful to quantify the number of HIV proviruses in cells against a background of unintegrated forms of the HIV DNA. A popular method for doing so involves quantitative PCR using one primer complementary to the HIV long terminal repeat (LTR), and a second primer complementary to a cellular Alu repeat, so that PCR product only forms from templates where a provirus is integrated in the human genome near an Alu repeat. However, several recent studies have identified conditions that alter distributions of HIV integration sites relative to genes. Because Alu repeats are enriched in gene rich regions, this raises the question of whether altered integration site distributions might confound provirus abundance measurements using the Alu-PCR method. Here modified versions of the HIV tethering protein LEDGF/p75 were used to retarget HIV integration outside of transcription units, and show that this has a negligible effect on Alu-PCR quantitation of proviral abundance. Thus altered integration targeting, at least to the degree achieved here, is not a major concern when using the Alu-PCR assay.

Background In June of 2009, the World Health Organization declared the first influenza pandemic of the 21st century, and by July, New York City's New York-Presbyterian Hospital (NYPH) experienced a heavy burden of cases, attributable to a novel strain of the virus (H1N1pdm). Methods and Results We present the signs in the NYPH electronic health records (EHR) that distinguished the 2009 pandemic from previous seasonal influenza outbreaks via various statistical analyses. These signs include (1) an increase in the number of patients diagnosed with influenza, (2) a preponderance of influenza diagnoses outside of the normal flu season, and (3) marked vaccine failure. The NYPH EHR also reveals distinct age distributions of patients affected by seasonal influenza and the pandemic strain, and via available longitudinal data, suggests that the two may be associated with distinct sets of comorbid conditions as well. In particular, we find significantly more pandemic flu patients with diagnoses associated with asthma and underlying lung disease. We further observe that the NYPH EHR is capable of tracking diseases at a resolution as high as particular zip codes in New York City. Conclusion The NYPH EHR permits early detection of pandemic influenza and hypothesis generation via identification of those significantly associated illnesses. As data standards develop and databases expand, EHRs will contribute more and more to disease detection and the discovery of novel disease associations.