Hospital Addiction Medicine Consultation Service Orders and Outcomes by Patient Race and Ethnicity in an Urban, Safety-Net Hospital.

BACKGROUND: Hospital admissions involving substance use disorders are increasing and represent an opportunity to engage patients in substance use treatment. Addiction medicine consultation services improve access to medications for opioid use disorder (MOUD) and patient outcomes. However, as hospitals continue to adopt addiction medicine consultation services it is important to identify where disparities may emerge in the process of care. OBJECTIVE: To describe addiction medicine consultation service use by race and ethnicity as well as substance to identify opportunities to reduce substance use treatment disparities. DESIGN: Retrospective cohort study using 2016-2021 Electronic Health Record data from a large Midwest safety-net hospital. PARTICIPANTS: Hospitalized adults aged 18 or older, with one or more substance use disorders. MAIN MEASURES: Consultation orders placed, patient seen by consult provider, and receipt of MOUD by self-reported race. KEY RESULTS: Between 2016 and 2021, we identified 16,895 hospitalized patients with a substance use disorder. Consultation orders were placed for 6344 patients and 2789 were seen by the consult provider. Black patients were less likely (aOR = 0.58; 95% CI: 0.53-0.63) to have an addiction medicine consultation order placed and, among patients with a consultation order, were less likely (aOR = 0.74; 95% CI: 0.65-0.85) to be seen by the consult provider than White patients. Overall, Black patients with OUD were also less likely to receive MOUD in the hospital (aOR = 0.63; 95% CI: 0.50-0.79) compared to White patients. However, there were no differences in MOUD receipt among Black and White patients seen by the consult provider. CONCLUSIONS: Using Electronic Health Record data, we identified racial and ethnic disparities at multiple points in the inpatient addiction medicine consultation process. Addressing these disparities may support more equitable access to MOUD and other substance use treatment in the hospital setting.

Trends in Substance Use Disorder-related Admissions at a Safety-net Hospital, 2008 - 2020.

OBJECTIVES: Safety-net hospitals disproportionately care for people with substance use disorders (SUDs), yet little is known about trends in hospital admissions related to specific substances. This study uses electronic health record data to describe trends in substance-specific admissions at a Midwest urban safety-net hospital. METHODS: We included all admissions from 2008 through 2020 and defined them as non-SUD (N = 154,477) or SUD-related (N = 63,667). We described patient characteristics and trends in substance-specific admissions. We estimated the association of SUD diagnoses with discharge against medical advice and length of stay using logistic regression and generalized linear models. RESULTS: Between 2008 and 2020, SUD-related admissions increased from 23.1% to 32.9% of total admissions. Admissions related to SUD had significantly more comorbidities than non-SUD-related admissions (4.7 vs 3.5, P < 0.001). Among illicit substances, cocaine-related admissions were the most common in 2008 (3.9% of total admissions, 17.2% of SUD admissions) whereas psychostimulants (eg, methamphetamines) were the most common in 2020 (7.8% of total admissions, 23.8% of SUD admissions). SUD-related hospitalizations had higher rates of against medical advice discharge (3.8%; 95% CI 3.6-3.9 vs 1.4%; 95% CI 1.3-1.4) and longer length of stay (6.3 days; 95% CI: 6.2-6.3 vs 5.3 days; 95% CI: 5.3-5.4) than non-SUD-related admissions. CONCLUSIONS: Over the study period, the proportion of admissions related to substance use rose to approximately one third of all admissions, driven by a rapidly increasing share of psychostimulant-related admissions. Identifying substance use patterns quickly using electronic health record data can help safety-net hospitals meet the needs of their patients and improve outcomes.

Pathophysiology of the rhesus macaque model for inhalational brucellosis.

The objective of this study was to characterize the rhesus macaque (RM) as a model for inhalational brucellosis in support of the U.S. Food and Drug Administration's (FDA) Animal Rule. The pathophysiology of chronic Brucella melitensis aerosol infection was monitored in two phases that each occurred over an 8-week time period; dose escalation (8 RMs; targeted doses of 5.0E+03, 5.0E+04, or 5.0E+05 CFU/animal or the unchallenged control) and natural history (12 RMs; targeted dose of 2.50E+05 CFU/animal or the unchallenged control). RMs given an aerosol challenge with B. melitensis developed undulating fevers (6/6 phase I; 8/9 phase II), positive enriched blood cultures (5/10; phase II), and bacterial burdens in tissues starting 14 to 21 days postchallenge (6/6 phase I; 10/10 phase II). In addition, 80% (8/10; phase II) of infected RMs seroconverted 14 to 21 days postchallenge. RMs developed elevations in certain liver enzymes and had an increased inflammatory response by 3 weeks postchallenge as shown by increases in C-reactive protein (6/8) and neopterin (4/8), which correlated with the onset of a fever. As early as 14 days postchallenge, positive liver biopsy specimens were detected (2/8), and ultrasound imaging showed the development of splenomegaly. Finally, histopathologic examination found lesions attributed to Brucella infection in the liver, kidney, lung, and/or spleen of all animals. The disease progression observed with the RMs in this study is analogous to human brucellosis pathophysiology. Thus, the results from this study support the use of the RM as an animal model for inhalational brucellosis to evaluate the efficacy of novel vaccines and therapeutics against B. melitensis.

E. coli K-12 and EHEC genes regulated by SdiA.

BACKGROUND: Escherichia and Salmonella encode SdiA, a transcription factor of the LuxR family that regulates genes in response to N-acyl homoserine lactones (AHLs) produced by other species of bacteria. E. coli genes that change expression in the presence of plasmid-encoded sdiA have been identified by several labs. However, many of these genes were identified by overexpressing sdiA on a plasmid and have not been tested for a response to sdiA produced from its natural position in the chromosome or for a response to AHL. METHODOLOGY/PRINCIPAL FINDINGS: We determined that two important loci reported to respond to plasmid-based sdiA, ftsQAZ and acrAB, do not respond to sdiA expressed from its natural position in the chromosome or to AHLs. To identify genes that are regulated by chromosomal sdiA and/or AHLs, we screened 10,000 random transposon-based luciferase fusions in E. coli K-12 and a further 10,000 in E. coli O157:H7 for a response to AHL and then tested these genes for sdiA-dependence. We found that genes encoding the glutamate-dependent acid resistance system are up-regulated, and fliE is down-regulated, by sdiA. Gene regulation by sdiA of E. coli is only partially dependent upon AHL. CONCLUSIONS/SIGNIFICANCE: The genes of E. coli that respond to plasmid-based expression of sdiA are largely different than those that respond to chromosomal sdiA and/or AHL. This has significant implications for determining the true function of AHL detection by E. coli.

Methods in cell-to-cell signaling in Salmonella.

Many bacteria can sense their population density. This has been termed "quorum sensing." The bacteria use this information to coordinate their behavior, essentially behaving as multicellular organisms. The paradigm of Gram-negative quorum sensing is the LuxL/LuxR-type system employed by Vibriofischeri to regulate luminescence. The LuxR transcription factor detects the presence of N-acylhomoserine lactones (AHLs) produced by LuxI. The AHL diffuses freely across the cell wall, and its accumulation signals a high population density within a confined space. Upon binding AHL, the LuxR transcription factor activates the luminescence genes. Homologous systems are used by numerous Gram-negative pathogens to regulate host interaction genes. The AHLs produced by different LuxI homologs can vary in the length and modification of their acyl side chain. In the first section of this chapter, we describe the use of bacterial biosensors to determine whether a particular bacterial species synthesizes AHLs. The second section describes how to identify AHL-responsive genes in Salmonella typhimurium, an organism that detects but does not synthesize AHLs. The approach described can be modified for use with any organism that responds to AHLs but does not synthesize them. The third section describes the use of recombination-based in vivo expression technology (RIVET) to study AHL detection in vitro and in vivo, in this case the mouse gut.

Effect of sdiA on biosensors of N-acylhomoserine lactones.

Many gram-negative bacteria synthesize N-acylhomoserine lactones (AHLs) and then use transcription factors of the LuxR family to sense and respond to AHL accumulation in the environment; this phenomenon is termed quorum sensing. Bacteria produce a variety of AHLs, and numerous bacterial reporter strains, or biosensors, that can detect subsets of these molecules have been constructed. Many of these are based on Escherichia coli because this species does not produce AHLs. However, both Escherichia and Salmonella spp. contain a LuxR homolog named SdiA that can detect exogenous AHL synthesized by other microbial species. In this study we have determined that sdiA of E. coli and Salmonella spp. can activate an RhlR-based biosensor plasmid in response to AHLs other than what the biosensor was designed to detect. SdiA does not activate LuxR-, LasR-, or AhyR-based biosensor plasmids, although the presence of sdiA in E. coli does interfere with the function of the AhyR-based biosensor. Because sdiA interferes with the function of two of the four reporters, we have constructed a set of E. coli biosensor strains that lack sdiA. The set includes control reporters that allow the luxR dependence of responses to be determined.