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1.
Nature ; 611(7937): 780-786, 2022 11.
Article in English | MEDLINE | ID: mdl-36385534

ABSTRACT

Enteric pathogens are exposed to a dynamic polymicrobial environment in the gastrointestinal tract1. This microbial community has been shown to be important during infection, but there are few examples illustrating how microbial interactions can influence the virulence of invading pathogens2. Here we show that expansion of a group of antibiotic-resistant, opportunistic pathogens in the gut-the enterococci-enhances the fitness and pathogenesis of Clostridioides difficile. Through a parallel process of nutrient restriction and cross-feeding, enterococci shape the metabolic environment in the gut and reprogramme 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. We find evidence of microbial interaction between these two pathogenic organisms in multiple mouse models of infection and patients infected with C. difficile. These findings provide mechanistic insights into the role of pathogenic microbiota in the susceptibility to and the severity of C. difficile infection.


Subject(s)
Clostridioides difficile , Enterococcus , Microbial Interactions , Animals , Humans , Mice , Anti-Bacterial Agents/pharmacology , Arginine/deficiency , Arginine/metabolism , Clostridioides difficile/metabolism , Clostridioides difficile/pathogenicity , Clostridioides difficile/physiology , Disease Models, Animal , Drug Resistance, Bacterial , Enterococcus/drug effects , Enterococcus/metabolism , Enterococcus/pathogenicity , Enterococcus/physiology , Gastrointestinal Microbiome/drug effects , Intestines/drug effects , Intestines/metabolism , Intestines/microbiology , Leucine/metabolism , Ornithine/metabolism , Virulence , Disease Susceptibility
2.
Proc Natl Acad Sci U S A ; 117(21): 11703-11714, 2020 05 26.
Article in English | MEDLINE | ID: mdl-32393645

ABSTRACT

Patients with hematological malignancies or undergoing hematopoietic stem cell transplantation are vulnerable to colonization and infection with multidrug-resistant organisms, including vancomycin-resistant Enterococcus faecium (VREfm). Over a 10-y period, we collected and sequenced the genomes of 110 VREfm isolates from gastrointestinal and blood cultures of 24 pediatric patients undergoing chemotherapy or hematopoietic stem cell transplantation for hematological malignancy at St. Jude Children's Research Hospital. We used patient-specific reference genomes to identify variants that arose over time in subsequent gastrointestinal and blood isolates from each patient and analyzed these variants for insight into how VREfm adapted during colonization and bloodstream infection within each patient. Variants were enriched in genes involved in carbohydrate metabolism, and phenotypic analysis identified associated differences in carbohydrate utilization among isolates. In particular, a Y585C mutation in the sorbitol operon transcriptional regulator gutR was associated with increased bacterial growth in the presence of sorbitol. We also found differences in biofilm-formation capability between isolates and observed that increased biofilm formation correlated with mutations in the putative E. faecium capsular polysaccharide (cps) biosynthetic locus, with different mutations arising independently in distinct genetic backgrounds. Isolates with cps mutations showed improved survival following exposure to lysozyme, suggesting a possible reason for the selection of capsule-lacking bacteria. Finally, we observed mutations conferring increased tolerance of linezolid and daptomycin in patients who were treated with these antibiotics. Overall, this study documents known and previously undescribed ways that VREfm evolve during intestinal colonization and subsequent bloodstream infection in immunocompromised pediatric patients.


Subject(s)
Enterococcus faecium , Gram-Positive Bacterial Infections/microbiology , Vancomycin-Resistant Enterococci , Anti-Bacterial Agents/pharmacology , Bacteremia/microbiology , Biofilms , Child , Enterococcus faecium/drug effects , Enterococcus faecium/genetics , Enterococcus faecium/pathogenicity , Evolution, Molecular , Female , Gastrointestinal Microbiome/genetics , Genome, Bacterial/genetics , Humans , Immunocompromised Host , Male , Mutation/genetics , Sorbitol/metabolism , Vancomycin-Resistant Enterococci/drug effects , Vancomycin-Resistant Enterococci/genetics , Vancomycin-Resistant Enterococci/pathogenicity
3.
PLoS Med ; 19(4): e1003961, 2022 04.
Article in English | MEDLINE | ID: mdl-35413054

ABSTRACT

BACKGROUND: Disease and disability from alcohol use disproportionately impact people in low- and middle-income countries (LMICs). While varied interventions have been shown to reduce alcohol use in high-income countries, their efficacy in LMICs has not been assessed. This systematic review describes current published literature on patient-level alcohol interventions in LMICs and specifically describes clinical trials evaluating interventions to reduce alcohol use in LMICs. METHODS AND FINDINGS: In accordance with PRISMA, we performed a systematic review using an electronic search strategy from January 1, 1995 to December 1, 2020. Title, abstract, as well as full-text screening and extraction were performed in duplicate. A meta-summary was performed on randomized controlled trials (RCTs) that evaluated alcohol-related outcomes. We searched the following electronic databases: PubMed, EMBASE, Scopus, Web of Science, Cochrane, WHO Global Health Library, and PsycINFO. Articles that evaluated patient-level interventions targeting alcohol use and alcohol-related harm in LMICs were eligible for inclusion. No studies were excluded based on language. After screening 5,036 articles, 117 articles fit our inclusion criteria, 75 of which were RCTs. Of these RCTs, 93% were performed in 13 middle-income countries, while 7% were from 2 low-income countries. These RCTs evaluated brief interventions (24, defined as any intervention ranging from advice to counseling, lasting less than 1 hour per session up to 4 sessions), psychotherapy or counseling (15, defined as an interaction with a counselor longer than a brief intervention or that included a psychotherapeutic component), health promotion and education (20, defined as an intervention encouraged individuals' agency of taking care of their health), or biologic treatments (19, defined as interventions where the biological function of alcohol use disorder (AUD) as the main nexus of intervention) with 3 mixing categories of intervention types. Due to high heterogeneity of intervention types, outcome measures, and follow-up times, we did not conduct meta-analysis to compare and contrast studies, but created a meta-summary of all 75 RCT studies. The most commonly evaluated intervention with the most consistent positive effect was a brief intervention; similarly, motivational interviewing (MI) techniques were most commonly utilized among the diverse array of interventions evaluated. CONCLUSIONS: Our review demonstrated numerous patient-level interventions that have the potential to be effective in LMICs, but further research to standardize interventions, populations, and outcome measures is necessary to accurately assess their effectiveness. Brief interventions and MI techniques were the most commonly evaluated and had the most consistent positive effect on alcohol-related outcomes. TRIAL REGISTRATION: Protocol Registry: PROSPERO CRD42017055549.


Subject(s)
Alcoholism , Developing Countries , Alcoholism/prevention & control , Humans , Income , Poverty , Psychotherapy
4.
Antimicrob Agents Chemother ; 66(10): e0014022, 2022 10 18.
Article in English | MEDLINE | ID: mdl-36165615

ABSTRACT

In orthopedic oncology, the implant of a megaprosthetic device is standard of care after large-scale tumor resection involving segmental removal of bone. Infection remains the leading cause of implant failure, often resulting in major morbidity. Perioperative antibiotic practices for megaprosthetic reconstructions are not standardized and are based on guidelines for conventional joint arthroplasties. This study aims to evaluate the efficacy of current prophylactic strategies for megaprosthetic reconstructions. We conducted a retrospective review of megaprosthetic reconstructions performed at Duke University from 2001 to 2021. Logistic regression with GEE was used to assess whether a prolonged course of postoperative antibiotics is associated with infection risk. We assessed the microbial profile and corresponding susceptibilities of megaprosthetic infections through record review. Additionally, we designed a pharmacokinetic subgroup analysis using liquid chromatography-tandem mass spectrometry to quantify antibiotic concentrations in surgical tissue. Wilcoxon rank-sum tests were used to correlate tissue concentrations with infection risk. Out of 184 cases, 23 (12.5%) developed infection within 1 year. Extended postoperative antibiotics were not significantly associated with infection risk (P = 0.23). Among 18 culture-positive cases, 4 (22.2%) were caused by cefazolin-susceptible organisms. Median bone and muscle concentrations of cefazolin among cases that developed postoperative infection (0.065 ng/mL and 0.2 ng/mL, respectively) were significantly lower than those of cases that did not (0.42 ng/mL and 1.95 ng/mL, P < 0.01 and P = 0.03). This study is the first to comprehensively assess aspects of perioperative prophylaxis for megaprosthetic reconstructions. Extending postoperative antibiotics did not reduce infection risk. We detected a high frequency of cefazolin nonsusceptible organisms among postoperative infections. Additionally, intraoperative antibiotic tissue concentrations may be predictive of later infection. Future studies ought to examine optimal drug choices and dosing strategies.


Subject(s)
Antibiotic Prophylaxis , Cefazolin , Humans , Cefazolin/therapeutic use , Anti-Bacterial Agents/therapeutic use , Retrospective Studies , Surgical Wound Infection/prevention & control , Surgical Wound Infection/drug therapy
5.
Ann Surg Oncol ; 29(2): 1392-1408, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34570333

ABSTRACT

BACKGROUND: Limited data are available to inform the risk of readmission and short-term mortality in musculoskeletal oncology. The goal of this study was to identify factors independently associated with 30-day readmission and 90-day mortality following surgical resection of chondrosarcoma. METHODS: We retrospectively reviewed 6653 patients following surgical resection of primary chondrosarcoma in the National Cancer Database (2004-2017). Both demographic and clinicopathologic variables were assessed for correlation with readmission and short-term mortality utilizing univariate and multivariate logistic regression modeling. RESULTS: Of 220 readmissions (3.26%), risk factors independently associated with an increased risk of unplanned 30-day readmission included Charlson-Deyo Comorbidity Index (CDCC) (odds ratio [OR] 1.31; p = 0.027), increasing American Joint Committee on Cancer (AJCC) stage (OR 1.31; p = 0.004), undergoing major amputation (OR 2.38; p = 0.001), and axial skeletal location (OR 1.51; p = 0.028). A total of 137 patients died within 90 days of surgery (2.25%). Risk factors associated with increased mortality included the CDCC (OR 1.60; p = 0.001), increasing age (OR 1.06; p < 0.001), having Medicaid insurance status (OR 3.453; p = 0.005), living in a zip code with a higher educational attainment (OR 1.59; p = 0.003), increasing AJCC stage (OR 2.32; p < 0.001), longer postoperative length of stay (OR 1.015; p = 0.033), and positive surgical margins (OR 2.75; p = 0.001). Although a majority of the cohort did not receive radiation therapy (88.8%), receiving radiotherapy (OR 0.132; p = 0.010) was associated with a decreased risk of short-term mortality. CONCLUSIONS: Several tumor, treatment, and patient factors can help inform the risk of readmission and short-term mortality in patients with surgically treated chondrosarcoma.


Subject(s)
Chondrosarcoma , Patient Readmission , Chondrosarcoma/surgery , Humans , Postoperative Complications , Retrospective Studies , Risk Factors , United States/epidemiology
6.
Ann Surg Oncol ; 28(12): 7961-7972, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34018083

ABSTRACT

BACKGROUND: There are limited data to inform risk of readmission and short-term mortality in musculoskeletal oncology. The goal of this study was to identify factors independently associated with 30-day readmission and 90-day mortality following surgical resection of osteosarcoma. METHODS: We retrospectively reviewed patients (n = 5293) following surgical resection of primary osteosarcoma in the National Cancer Database (2004-2015). Univariate and multivariate methods were used to correlate variables with readmission and short-term mortality. RESULTS: Of 210 readmissions (3.97%), risk factors independently associated with unplanned 30-day readmission included comorbidity burden (odds ratio [OR] 2.4, p = 0.042), Medicare insurance (OR 1.9, p = 0.021), and axial skeleton location (OR 1.5, p = 0.029). A total of 91 patients died within 90 days of their surgery (1.84%). Risk factors independently associated with mortality included age (hazard ratio 1.1, p < 0.001), increasing comorbidity burden (OR 6.6, p = 0.001), higher grade (OR 1.7, p = 0.007), increasing tumor size (OR 2.2, p = 0.03), metastatic disease at presentation (OR 8.5, p < 0.001), and amputation (OR 2.0, p = 0.04). Chemotherapy was associated with a decreased risk of short-term mortality (p < 0.001). CONCLUSIONS: Several trends were clear: insurance status, tumor location and comorbidity burden were independently associated with readmission rates, while age, amputation, grade, tumor size, metastatic disease, and comorbidity burden were independently associated with short-term mortality.


Subject(s)
Bone Neoplasms , Osteosarcoma , Aged , Comorbidity , Databases, Factual , Humans , Medicare , Osteosarcoma/surgery , Patient Readmission , Postoperative Complications/epidemiology , Retrospective Studies , Risk Factors , United States/epidemiology
7.
Emerg Infect Dis ; 26(2): 366-369, 2020 02.
Article in English | MEDLINE | ID: mdl-31961306

ABSTRACT

We describe 2 human cases of infection with a new Neisseria species (putatively N. brasiliensis), 1 of which involved bacteremia. Genomic analyses found that both isolates were distinct strains of the same species, were closely related to N. iguanae, and contained a capsule synthesis operon similar to N. meningitidis.


Subject(s)
Meningococcal Infections/diagnosis , Neisseria/isolation & purification , Aged , Brazil , Female , Humans , Male , Middle Aged , Neisseria/genetics
8.
J Clin Microbiol ; 58(9)2020 08 24.
Article in English | MEDLINE | ID: mdl-32554477

ABSTRACT

Carbapenem-nonsusceptible Citrobacter spp. (CNSC) are increasingly recognized as health care-associated pathogens. Information regarding their clinical epidemiology, genetic diversity, and mechanisms of carbapenem resistance is lacking. We examined microbiology records of adult patients at the University of Pittsburgh Medical Center (UMPC) Presbyterian Hospital (PUH) from 2000 to 2018 for CNSC, as defined by ertapenem nonsusceptibility. Over this time frame, the proportion of CNSC increased from 4% to 10% (P = 0.03), as did daily defined carbapenem doses/1,000 patient days (6.52 to 34.5; R2 = 0.831; P < 0.001), which correlated with the observed increase in CNSC (lag = 0 years; R2 = 0.660). Twenty CNSC isolates from 19 patients at PUH and other UPMC hospitals were available for further analysis, including whole-genome short-read sequencing and additional antimicrobial susceptibility testing. Of the 19 patients, nearly all acquired CNSC in the health care setting and over half had polymicrobial cultures containing at least one other organism. Among the 20 CNSC isolates, Citrobacter freundii was the predominant species identified (60%). CNSC genomes were compared with genomes of carbapenem-susceptible Citrobacter spp. from UPMC and with other publicly available CNSC genomes. Isolates carrying genes encoding carbapenemases (blaKPC-2,blaKPC-3, and blaNDM-1) were also long-read sequenced, and their carbapenemase-encoding plasmid sequences were compared with one another and with publicly available sequences. Phylogenetic analysis of 102 UPMC Citrobacter genomes showed that CNSC from our setting did not cluster together. Similarly, a global phylogeny of 64 CNSC genomes showed a diverse population structure. Our findings suggest that both local and global CNSC populations are genetically diverse and that CNSC harbor carbapenemase-encoding plasmids found in other Enterobacterales.


Subject(s)
Carbapenems , Enterobacteriaceae Infections , Adult , Anti-Bacterial Agents/pharmacology , Bacterial Proteins/genetics , Carbapenems/pharmacology , Citrobacter/genetics , Delivery of Health Care , Enterobacteriaceae Infections/epidemiology , Genomics , Humans , Phylogeny , beta-Lactamases/genetics
9.
BMC Cancer ; 20(1): 995, 2020 Oct 14.
Article in English | MEDLINE | ID: mdl-33054722

ABSTRACT

BACKGROUND: Historically, amputation was the primary surgical treatment for osteosarcoma of the extremities; however, with advancements in surgical techniques and chemotherapies limb salvage has replaced amputation as the dominant treatment paradigm. This study assessed the type of surgical resection chosen for osteosarcoma patients in the twenty-first century. METHODS: Utilizing the largest registry of primary osteosarcoma, the National Cancer Database (NCDB), we retrospectively analyzed patients with high grade osteosarcoma of the extremities from 2004 through 2015. Differences between patients undergoing amputation and patients undergoing limb salvage are described. Unadjusted five-year overall survival between patients who received limb salvage and amputation was assessed utilizing Kaplan Meier curves. A multivariate Cox proportional hazard model and propensity matched analysis was used to determine the variables independently correlated with survival. RESULTS: From a total of 2442 patients, 1855 underwent limb salvage and 587 underwent amputation. Patients undergoing amputation were more likely to be older, male, uninsured, and live in zip codes associated with lower income. Patients undergoing amputation were also more likely to have larger tumors, more comorbid conditions, and metastatic disease at presentation. After controlling for confounders, limb salvage was associated with a significant survival benefit over amputation (HR: 0.70; p < 0.001). Although this may well reflect underlying biases impacting choice of treatment, this survival benefit remained significant after propensity matched analysis of all significantly different independent variables (HR: 0.71; p < 0.01). CONCLUSION: Among patients in the NCDB, amputation for osteosarcoma is associated with advanced age, advanced stage, larger tumors, greater comorbidities, and lower income. Limb salvage is associated with a significant survival benefit, even when controlling for significant confounding variables and differences between cohorts.


Subject(s)
Amputation, Surgical/methods , Extremities/pathology , Limb Salvage/methods , Osteosarcoma/surgery , Adolescent , Adult , Databases, Factual , Female , Humans , Male , Osteosarcoma/mortality , Retrospective Studies , Survival Analysis , United States , Young Adult
10.
Malar J ; 18(1): 5, 2019 Jan 09.
Article in English | MEDLINE | ID: mdl-30626380

ABSTRACT

BACKGROUND: Global efforts to address the burden of malaria have stagnated in recent years with malaria cases beginning to rise. Substandard and falsified anti-malarial treatments contribute to this stagnation. Poor quality anti-malarials directly affect health outcomes by increasing malaria morbidity and mortality, as well as threaten the effectiveness of treatment by contributing to artemisinin resistance. Research to assess the scope and impact of poor quality anti-malarials is essential to raise awareness and allocate resources to improve the quality of treatment. A probabilistic agent-based model was developed to provide country-specific estimates of the health and economic impact of poor quality anti-malarials on paediatric malaria. This paper presents the methodology and case study of the Substandard and Falsified Antimalarial Research Impact (SAFARI) model developed and applied to Uganda. RESULTS: The total annual economic impact of malaria in Ugandan children under age five was estimated at US$614 million. Among children who sought medical care, the total economic impact was estimated at $403 million, including $57.7 million in direct costs. Substandard and falsified anti-malarials were a significant contributor to this annual burden, accounting for $31 million (8% of care-seeking children) in total economic impact involving $5.2 million in direct costs. Further, 9% of malaria deaths relating to cases seeking treatment were attributable to poor quality anti-malarials. In the event of widespread artemisinin resistance in Uganda, we simulated a 12% yearly increase in costs associated with paediatric malaria cases that sought care, inflicting $48.5 million in additional economic impact annually. CONCLUSIONS: Improving the quality of treatment is essential to combat the burden of malaria and prevent the development of drug resistance. The SAFARI model provides country-specific estimates of the health and economic impact of substandard and falsified anti-malarials to inform governments, policy makers, donors and the malaria community about the threat posed by poor quality medicines. The model findings are useful to illustrate the significance of the issue and inform policy and interventions to improve medicinal quality.


Subject(s)
Antimalarials/analysis , Antimalarials/standards , Counterfeit Drugs/analysis , Malaria/drug therapy , Malaria/economics , Artemisinins , Child, Preschool , Counterfeit Drugs/economics , Drug Resistance , Female , Humans , Infant , Male , Models, Theoretical , Private Sector , Uganda
11.
Hum Mutat ; 39(8): 1092-1101, 2018 08.
Article in English | MEDLINE | ID: mdl-29749045

ABSTRACT

Characterizing moderate penetrance susceptibility genes is an emerging frontier in colorectal cancer (CRC) research. GALNT12 is a strong candidate CRC-susceptibility gene given previous linkage and association studies, and inactivating somatic and germline alleles in CRC patients. Previously, we found rare segregating germline GALNT12 variants in a clinic-based cohort (N = 118) with predisposition for CRC. Here, we screened a new population-based cohort of incident CRC cases (N = 479) for rare (MAF ≤1%) deleterious germline GALNT12 variants. GALNT12 screening revealed eight rare variants. Two variants were previously described (p.Asp303Asn, p.Arg297Trp), and additionally, we found six other rare variants: five missense (p.His101Gln, p.Ile142Thr, p.Glu239Gln, p.Thr286Met, p.Val290Phe) and one putative splice-altering variant (c.732-8 G>T). Sequencing of population-matched controls (N = 400) revealed higher burden of these variants in CRC cases compared with healthy controls (P = 0.0381). We then functionally characterized the impact of substitutions on GALNT12 enzyme activity using in vitro-derived peptide substrates. Three of the newly identified GALNT12 missense variants (p.His101Gln, p.Ile142Thr, p.Val290Phe) demonstrated a marked loss (>2-fold reduction) of enzymatic activity compared with wild-type (P ≤ 0.05), whereas p.Glu239Gln exhibited a ∼2-fold reduction in activity (P = 0.077). These findings provide strong, independent evidence for the association of GALNT12 defects with CRC-susceptibility; underscoring implications for glycosylation pathway defects in CRC.


Subject(s)
Colorectal Neoplasms/genetics , N-Acetylgalactosaminyltransferases/genetics , Blotting, Western , Cell Line, Tumor , Genetic Predisposition to Disease/genetics , Genotype , Humans , Microsatellite Repeats/genetics , Recombinant Proteins/genetics
12.
Infect Immun ; 85(9)2017 09.
Article in English | MEDLINE | ID: mdl-28652312

ABSTRACT

Clostridium perfringens can produce up to three different sialidases, including NanI, its major exosialidase. The current study first showed that human intestinal strains of C. perfringens can grow by utilizing either glucose or sialic acids, such as N-acetylneuraminic acid (Neu5Ac), which are the end products of sialidase activity. For the human enteropathogenic strain F4969, it was then determined that culture supernatant sialidase activity and expression of exosialidase genes, particularly nanI, are influenced by the presence of Neu5Ac or glucose. Low Neu5Ac concentrations increased culture supernatant sialidase activity, largely by stimulating nanI transcription. In contrast, low glucose concentrations did not affect exosialidase activity or nanI transcription. However, either high Neu5Ac or high glucose concentrations repressed F4969 culture supernatant sialidase activity and nanI transcription levels. Furthermore, high glucose levels repressed F4969 culture sialidase activity and nanI expression even in the presence of low Neu5AC concentrations. To begin to evaluate the mechanistic basis for nanI expression, a nanR null mutant was used to demonstrate that NanR, a member of the RpiR family of regulatory proteins, decreases exosialidase activity and nanI transcription in the absence of sialic acid. The ability of C. perfringens to regulate its exosialidase activity, largely by controlling nanI expression, may affect intestinal pathogenesis by affecting the production of NanI, which may affect C. perfringens growth, adhesion, and toxin binding in vivo.


Subject(s)
Clostridium perfringens/genetics , DNA-Binding Proteins/metabolism , Gene Expression Regulation, Bacterial , Neuraminidase/biosynthesis , Clostridium perfringens/growth & development , Clostridium perfringens/metabolism , Gene Expression Profiling , Glucose/metabolism , Humans , Sialic Acids/metabolism , Transcription, Genetic
13.
Infect Immun ; 85(3)2017 03.
Article in English | MEDLINE | ID: mdl-28052992

ABSTRACT

Clostridium perfringens type D strains cause enterotoxemia and enteritis in livestock via epsilon toxin production. In type D strain CN3718, CodY was previously shown to increase the level of epsilon toxin production and repress sporulation. C. perfringens type A strains producing C. perfringens enterotoxin (CPE) cause human food poisoning and antibiotic-associated diarrhea. Sporulation is critical for C. perfringens type A food poisoning since spores contribute to transmission and resistance in the harsh food environment and sporulation is essential for CPE production. Therefore, the current study asked whether CodY also regulates sporulation and CPE production in SM101, a derivative of C. perfringens type A food-poisoning strain NCTC8798. An isogenic codY-null mutant of SM101 showed decreased levels of spore formation, along with lower levels of CPE production. A complemented strain recovered wild-type levels of both sporulation and CPE production. When this result was coupled with the earlier results obtained with CN3718, it became apparent that CodY regulation of sporulation varies among different C. perfringens strains. Results from quantitative reverse transcriptase PCR analysis clearly demonstrated that, during sporulation, codY transcript levels remained high in SM101 but rapidly declined in CN3718. In addition, abrB gene expression patterns varied significantly between codY-null mutants of SM101 and CN3718. Compared to the levels in their wild-type parents, the level of abrB gene expression decreased in the CN3718 codY-null mutant strain but significantly increased in the SM101 codY-null mutant strain, demonstrating CodY-dependent regulation differences in abrB expression between these two strains. This difference appears to be important since overexpression of the abrB gene in SM101 reduced the levels of sporulation and enterotoxin production, supporting the involvement of AbrB repression in regulating C. perfringens sporulation.


Subject(s)
Bacterial Proteins/metabolism , Clostridium perfringens/physiology , Enterotoxins/biosynthesis , Spores, Bacterial/physiology , Transcription Factors/metabolism , Bacterial Proteins/genetics , Clostridium Infections/microbiology , Gene Expression Regulation, Bacterial , Genetic Complementation Test , Mutation , Transcription Factors/genetics
14.
Pers Soc Psychol Rev ; 20(4): 291-310, 2016 Nov.
Article in English | MEDLINE | ID: mdl-26228914

ABSTRACT

Self-regulation requires overriding a dominant response and leads to temporary self-regulatory fatigue. Existing theories of the nature and causes of self-regulatory fatigue highlight physiological substrates such as glucose, or psychological processes such as motivation, but these explanations are incomplete on their own. Historically, theories of physical fatigue demonstrate a similar pattern of useful but incomplete explanations, as recent views of physical fatigue emphasize the roles of both physiological and psychological factors. In addition to accounting for multiple inputs, these newer views also explain how fatigue can occur even in the presence of sufficient resources. Examining these newer theories of physical fatigue can serve as a foundation on which to build a more comprehensive understanding of self-regulatory fatigue that integrates possible neurobiological underpinnings of physical and self-regulatory fatigue, and suggests the possible function of self-regulatory fatigue.

15.
Exp Aging Res ; 41(5): 534-45, 2015.
Article in English | MEDLINE | ID: mdl-26524235

ABSTRACT

BACKGROUND/STUDY CONTEXT: Physical activity is beneficial for the executive functioning (EF) of older adults, but may be particularly protective of EF when they are cognitively vulnerable, such as during depressive episodes. Intervention studies support more potent effects of physical activity on EF among clinically depressed older adults, although these results may have limited generalizability to the daily mood and physical activity of healthy, community-dwelling older adults. METHODS: The current study aimed to test whether physical activity among older adults was more protective of EF during periods of cognitive vulnerability due to mildly elevated depressive symptoms. Longitudinal data from 150 generally healthy, community-dwelling older adults were collected semiannually and analyzed with multilevel modeling. RESULTS: Physical activity was more protective of EF within individuals during periods of relatively elevated depressive symptoms. CONCLUSIONS: The power of physical activity to protect EF during periods of cognitive vulnerability may extend to community-dwelling older adults with nonclinical levels of depressive symptoms.


Subject(s)
Cognition Disorders/complications , Cognition Disorders/psychology , Depressive Disorder/complications , Depressive Disorder/psychology , Executive Function , Exercise , Aged , Aging/psychology , Female , Humans , Male , Residence Characteristics
16.
J Appl Soc Psychol ; 44(1): 23-30, 2014 Jan.
Article in English | MEDLINE | ID: mdl-25843972

ABSTRACT

Training in mindfulness is a well-supported therapeutic strategy for pain conditions, though short-term mindfulness training for acute pain is not always effective. To explore the possibility that initial attempts at mindfulness in people without previous training may drain self-regulatory resources, the current study used a student sample (N=63) to test the hypothesis that brief instruction in mindfulness would lead to reduced pain tolerance on a cold pressor task (CPT), compared to more familiar strategies for coping with acute pain. We also investigated whether high heart rate variability (HRV), a physiological indicator of self-regulatory capacity, would predict pain tolerance. Higher HRV predicted greater pain tolerance only in the control group, suggesting that applying unfamiliar mindfulness strategies while attempting to tolerate pain more rapidly sapped self-regulatory strength.

17.
Behav Med ; 39(3): 73-9, 2013.
Article in English | MEDLINE | ID: mdl-23930899

ABSTRACT

The relationship between behavior (eg, diet, exercise, substance use) and the functioning of chronic-pain patients, including orofacial-pain patients, is poorly understood. This preliminary study examined cigarette smoking and both pain-related and psychological functioning in female orofacial-pain patients. Correlates of intentions to quit smoking were also explored. There were 48 participants in this cross-sectional study. Smokers reported significantly less self-control over pain (d = .66), lower general activity levels (d = .52), more fatigue (d = .80), and poorer sleep quality (d = .53) than non-smokers. The mean effect size for all dependent variables was .49 (range, .33-.80) with the smallest and largest effect found for negative mood and fatigue, respectively. More positive attitudes toward smoking cessation independently predicted stronger intentions to quit (ß = .52, p = .03). Findings suggest smoking is significantly associated with pain-related and psychological functioning in female orofacial-pain patients. Smoking-cessation treatment for these patients should include motivational interviewing techniques directed toward attitudinal change.


Subject(s)
Facial Pain/psychology , Intention , Smoking Cessation/psychology , Smoking/psychology , Tobacco Use Disorder/psychology , Adult , Chronic Pain/complications , Chronic Pain/psychology , Cross-Sectional Studies , Facial Pain/complications , Female , Humans , Middle Aged , Surveys and Questionnaires , Tobacco Use Disorder/complications
18.
Brain Behav Immun ; 26(5): 747-53, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22062498

ABSTRACT

Psychological distress and biobehavioral vulnerability (e.g., arising from being older or sedentary) have independently predicted immune responses to influenza vaccination in older adults. Recent research examining basal inflammatory markers suggests that, rather than having additive effects, distress and vulnerability interact with each other. The present study tested the interactions between distress and age, sex, education, BMI, sleep quality, and physical activity over up to 8 years in older adults (N=134; M age=74 years) who received annual influenza vaccinations. Measured vaccination responses were changes from baseline in antibody to the three vaccine components, interleukin (IL)-6, and ß2-microglobulin. As predicted, the most robust effects were interactions between distress and vulnerability. BMI interacted with stable individual differences in distress to predict antibody response (t(132)=3.09, p<0.003), such that only the combination of low BMI and low distress was associated with a more robust antibody response. Likewise, changes in physical activity over time interacted with changes in distress (t(156)=2.96, p<0.004), such that only the combination of increased physical activity and decreased distress was associated with a more robust antibody response. Finally, there was a smaller tendency for age to interact with stable individual differences in distress (t(130)=2.46, p<0.015), such that distress was more strongly associated with post-vaccination IL-6 at older ages. The synergistic effects of distress and other forms of vulnerability are an important direction for future research and a target for interventions to improve immunological health in older adults.


Subject(s)
Stress, Psychological/immunology , Stress, Psychological/psychology , Vaccination/psychology , Aged , Aged, 80 and over , Aging/immunology , Aging/physiology , Antibody Formation/physiology , Body Mass Index , Data Interpretation, Statistical , Depression/psychology , Drug Therapy , Educational Status , Female , Humans , Individuality , Inflammation/physiopathology , Influenza Vaccines/adverse effects , Influenza Vaccines/immunology , Influenza, Human/prevention & control , Interleukin-6/biosynthesis , Male , Middle Aged , Sedentary Behavior , Sex Characteristics , Sleep Wake Disorders/immunology , Socioeconomic Factors , Treatment Outcome , Vaccination/adverse effects
19.
Genes (Basel) ; 13(3)2022 03 07.
Article in English | MEDLINE | ID: mdl-35328024

ABSTRACT

Autism spectrum disorder (ASD) describes a complex and heterogenous group of neurodevelopmental disorders. Whole genome sequencing continues to shed light on the multifactorial etiology of ASD. Dysregulated transcriptional pathways have been implicated in neurodevelopmental disorders. Emerging evidence suggests that de novo POLR2A variants cause a newly described phenotype called 'Neurodevelopmental Disorder with Hypotonia and Variable Intellectual and Behavioral Abnormalities' (NEDHIB). The variable phenotype manifests with a spectrum of features; primarily early onset hypotonia and delay in developmental milestones. In this study, we investigate a patient with complex ASD involving epilepsy and strabismus. Whole genome sequencing of the proband−parent trio uncovered a novel de novo POLR2A variant (c.1367T>C, p. Val456Ala) in the proband. The variant appears deleterious according to in silico tools. We describe the phenotype in our patient, who is now 31 years old, draw connections between the previously reported phenotypes and further delineate this emerging neurodevelopmental phenotype. This study sheds new insights into this neurodevelopmental disorder, and more broadly, the genetic etiology of ASD.


Subject(s)
Autism Spectrum Disorder , Epilepsy , Intellectual Disability , Self-Injurious Behavior , Strabismus , Autism Spectrum Disorder/genetics , DNA-Directed RNA Polymerases/genetics , Epilepsy/genetics , Humans , Intellectual Disability/genetics , Muscle Hypotonia/genetics , Strabismus/genetics
20.
mSystems ; 7(3): e0138421, 2022 06 28.
Article in English | MEDLINE | ID: mdl-35695507

ABSTRACT

Healthcare-associated infections (HAIs) cause mortality, morbidity, and waste of health care resources. HAIs are also an important driver of antimicrobial resistance, which is increasing around the world. Beginning in November 2016, we instituted an initiative to detect outbreaks of HAIs using prospective whole-genome sequencing-based surveillance of bacterial pathogens collected from hospitalized patients. Here, we describe the diversity of bacteria sampled from hospitalized patients at a single center, as revealed through systematic analysis of bacterial isolate genomes. We sequenced the genomes of 3,004 bacterial isolates from hospitalized patients collected over a 25-month period. We identified bacteria belonging to 97 distinct species, which were distributed among 14 groups of related species. Within these groups, isolates could be distinguished from one another by both average nucleotide identity (ANI) and principal-component analysis of accessory genes (PCA-A). Core genome genetic distances and rates of evolution varied among species, which has practical implications for defining shared ancestry during outbreaks and for our broader understanding of the origins of bacterial strains and species. Finally, antimicrobial resistance genes and putative mobile genetic elements were frequently observed, and our systematic analysis revealed patterns of occurrence across the different species sampled from our hospital. Overall, this study shows how understanding the population structure of diverse pathogens circulating in a single health care setting can improve the discriminatory power of genomic epidemiology studies and can help define the processes leading to strain and species differentiation. IMPORTANCE Hospitalized patients are at increased risk of becoming infected with antibiotic-resistant organisms. We used whole-genome sequencing to survey and compare over 3,000 clinical bacterial isolates collected from hospitalized patients at a large medical center over a 2-year period. We identified nearly 100 different bacterial species, which we divided into 14 different groups of related species. When we examined how genetic relatedness differed between species, we found that different species were likely evolving at different rates within our hospital. This is significant because the identification of bacterial outbreaks in the hospital currently relies on genetic similarity cutoffs, which are often applied uniformly across organisms. Finally, we found that antibiotic resistance genes and mobile genetic elements were abundant and were shared among the bacterial isolates we sampled. Overall, this study provides an in-depth view of the genomic diversity and evolutionary processes of bacteria sampled from hospitalized patients, as well as genetic similarity estimates that can inform hospital outbreak detection and prevention efforts.


Subject(s)
Genome, Bacterial , Genomics , Humans , Genome, Bacterial/genetics , Whole Genome Sequencing , Anti-Bacterial Agents , Hospitals
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