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We have previously reported on the susceptibility and epidemiology of Clostridioides difficile isolates from six geographically dispersed medical centers in the United States. This current survey was conducted with isolates collected in 2020-2021 from six geographically dispersed medical centers in the United States, with specific attention to susceptibility to ridinilazole as well as nine comparators. C. difficile isolates or stools from patients with C. difficile antibiotic-associated diarrhea were collected and referred to a central laboratory. After species confirmation of 300 isolates at the central laboratory, antibiotic susceptibilities were determined by the agar dilution method [M11-A9, Clinical and Laboratory Standards Institute (CLSI)] against the 10 agents. Ribotyping was performed by PCR capillary gel electrophoresis on all isolates. Ridinilazole had a minimum inhibitory concentration (MIC) 90 of 0.25 mcg/mL, and no isolate had an MIC greater than 0.5 mcg/mL. In comparison, fidaxomicin had an MIC 90 of 0.5 mcg/mL. The vancomycin MIC 90 was 2 mcg/mL with a 0.7% resistance rate [both CLSI and European Committee on Antimicrobial Susceptibility Testing (EUCAST) criteria]. The metronidazole MIC 90 was 1 mcg/mL, with none resistant by CLSI criteria, and a 0.3% resistance rate by EUCAST criteria. Among the 50 different ribotypes isolated in the survey, the most common ribotype was 014-020 (14.0%) followed by 106 (10.3%), 027 (10%), 002 (8%), and 078-126 (4.3%). Ridinilazole maintained activity against all ribotypes and all strains resistant to any other agent tested. Ridinilazole showed excellent in vitro activity against C. difficile isolates collected between 2020 and 2021 in the United States, independent of ribotype.
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Clostridioides difficile , Infecções por Clostridium , Humanos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Clostridioides difficile/genética , Clostridioides , Infecções por Clostridium/tratamento farmacológico , Infecções por Clostridium/epidemiologia , Testes de Sensibilidade Microbiana , RibotipagemRESUMO
Circadian rhythms influence virtually all aspects of physiology and behavior. This is problematic when circadian rhythms no longer reliably predict time. Circadian rhythm disruption can impair memory, yet we don't know how this fully works at the systems and molecular level. When trying to determine the root of a memory impairment, assessing neuronal activation with c-FOS is useful. This has yet to be assessed in the hippocampi of circadian rhythm disrupted rats in a hippocampal gold standard task. Rats were trained on the Morris water task (MWT), then received 6 days of a 21-h day (T21), 13 days of a normal light dark cycle, probe trial, and tissue extraction an hour later. Despite having impaired memory in the probe trial, compared to controls there were no differences in c-FOS expression in hippocampal sub regions: CA1; CA3; Dentate gyrus. These data confirm others in hamsters demonstrating that arrhythmicity which produces an impairment in spontaneous alternation does not affect c-FOS in the dentate gyrus. The current study indicates that the memory impairment induced by a lighting manipulation is likely not due to attenuated neuronal activation. Determining how the master clock in the brain communicates with the hippocampus is needed to untangle the relationship between circadian rhythms and memory.
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PURPOSE/OBJECTIVES: Radiation recall dermatitis (RRD) is a skin reaction limited to an area of prior radiation triggered by the subsequent introduction of systemic therapy. To characterize RRD, we conducted a literature search, summarized RRD features, and compared the most common drug classes implicated in this phenomenon. MATERIALS/METHODS: PubMed, Embase, Scopus, Web of Science, and Cochrane DBSR databases were queried through July 1, 2019 using key words: radiation recall, RRD, and radiodermatitis (limited to humans and English language). Studies included case reports in which patients treated with radiotherapy were initiated on a new line of systemic therapy and subsequently developed a skin reaction in the irradiated area. RRD cases were organized by whether RRD occurred after a single drug or multiple drug administration. RESULTS: One-hundred fifteen studies representing 129 RRD cases (96 single-drug RRD, 33 multi-drug) were included. Sixty-three drugs were associated with RRD. Docetaxel (22) and gemcitabine (18) were the two drugs most commonly associated with RRD. Breast cancer (69 cases) was the most commonly associated tumor type. For single-drug RRD, the median radiotherapy dose was 45.0 Gy (range, 30.0-63.2 Gy). The median time from radiotherapy to drug exposure, time from drug exposure to RRD and time to significant improvement was 8 weeks (range, 2-132 weeks), 5 days (range, 2-56 days), and 14 days (range, 7-49 days), respectively. Variables significantly associated with grade ≥2 toxicity were docetaxel (Pâ¯=â¯0.04) and non-antifolate antimetabolite (Pâ¯=â¯0.05). The only variable significantly associated with grade ≥3 toxicity was capecitabine (Pâ¯=â¯0.04). CONCLUSIONS: RRD is a complex toxicity that can occur after a wide range of radiotherapy doses and many different systemic agents. Most commonly, it presents in patients diagnosed with breast cancer and after administration of a taxane or antimetabolite medication. RRD treatment generally consists of corticosteroids with consideration of antibiotics if superinfection is suspected. Drug re-challenge may be considered after RRD if the initial reaction was of mild intensity.
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Neoplasias da Mama , Radiodermite , Antimetabólitos/uso terapêutico , Neoplasias da Mama/complicações , Neoplasias da Mama/radioterapia , Docetaxel , Feminino , Humanos , Radiodermite/diagnóstico , Radiodermite/epidemiologia , Radiodermite/etiologiaRESUMO
Our aim is to develop and apply next generation approaches to skin allergy risk assessment (SARA) that do not require new animal test data and better quantify uncertainties. Significant progress has been made in the development of New Approach Methodologies (NAMs), non-animal test methods, for assessment of skin sensitisation and there is now focus on their application to derive potency information for use in Next Generation Risk Assessment (NGRA). The SARA model utilises a Bayesian statistical approach to infer a human-relevant metric of sensitiser potency and a measure of risk associated with a given consumer exposure based upon any combination of human repeat insult patch test, local lymph node, direct peptide reactivity assay, KeratinoSens™, h-CLAT or U-SENS™ data. Here we have applied the SARA model within our weight of evidence NGRA framework for skin allergy to three case study materials in four consumer products. Highlighting how to structure the risk assessment, apply NAMs to derive a point of departure and conclude on consumer safety risk. NGRA based upon NAMs were, for these exposures, at least as protective as the historical risk assessment approaches. Through such case studies we are building our confidence in using NAMs for skin allergy risk assessment.
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Cosméticos , Dermatite Alérgica de Contato , Hipersensibilidade , Alternativas aos Testes com Animais/métodos , Animais , Teorema de Bayes , Tomada de Decisões , Dermatite Alérgica de Contato/diagnóstico , Dermatite Alérgica de Contato/etiologia , Medição de Risco/métodos , PeleRESUMO
PURPOSE/OBJECTIVES: We sought to investigate the impact of patient-reported outcomes version of the common terminology criteria for adverse events (PRO-CTCAE) on overall quality-of-life (QOL) employing linear analogue self-assessment (LASA) in breast cancer (BC) patients undergoing radiation therapy (RT). MATERIALS/METHODS: All patients treated with RT for BC with curative intent from 2015 to 2019 at our institution were included. Breast specific PRO-CTCAE and overall QOL LASA questionnaires were administered at baseline, end-of-treatment, 3, 6, 12 months, and then annually. Minimal clinically important difference in overall QOL was a 10-point change in LASA. Hypofractionation was any treatment > 2 Gy per fraction. Mixed models for repeated measures were used to determine the association of PRO-CTCAE and overall QOL LASA. RESULTS: Three hundred thirty-one (331) patients with a median follow-up of 3.1 years (range 0.4-4.9) were included. Average overall QOL LASA scores were 78.5 at baseline, 79.8 at end-of-treatment, 79.8 at 3 months, 77.1 at 6 months, 79.4 at 12 months, and 79.7 at 24 months. On univariate analysis, patients reporting a grade ≥ 3 PRO-CTCAE had, on average, a 10.4-point reduction in overall LASA QOL (p < 0.0001). On multivariate analysis, not being treated with hypofractionation and higher BMI were predictive for worse overall LASA QOL with a 10-point reduction in LASA for patients reporting a grade ≥ 3 PRO-CTCAE (p < 0.0001). CONCLUSIONS: Patients reporting a grade ≥ 3 PRO-CTCAE experienced statistically significant and clinically meaningful deterioration in overall QOL LASA. Hypofractionation improved QOL while higher BMI predicted for worse QOL. PRO-CTCAE should be integrated into future clinical trials.
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As national populations age, demands on critical care services are expected to increase. In many healthcare settings, longitudinal trends indicate rising numbers and proportions of patients admitted to ICU who are older; elsewhere, including some parts of the UK, a decrease has raised concerns with regard to rationing according to age. Our aim was to investigate admission trends in Wales, where critical care capacity has not risen in the last decade. We used the Secure Anonymised Information Linkage Databank to identify and characterise critical care admissions in patients aged ≥ 18 years from 1 January 2008 to 31 December 2017. We categorised 85,629 ICU admissions as youngest (18-64 years), older (65-79 years) and oldest (≥ 80 years). The oldest group accounted for 15% of admissions, the older age group 39% and the youngest group 46%. Relative to the national population, the incidence of admission rates per 10,000 population in the oldest group decreased significantly over the study period from 91.5/10,000 in 2008 to 77.5/10,000 (a relative decrease of 15%), and among the older group from 89.2/10,000 in 2008 to 75.3/10,000 in 2017 (a relative decrease of 16%). We observed significant decreases in admissions with high comorbidity (modified Charlson comorbidity index); increases in the proportion of older patients admitted who were considered 'fit' rather than frail (electronic frailty index); and decreases in admissions with a medical diagnosis. In contrast to other healthcare settings, capacity constraints and surgical imperatives appear to have contributed to a relative exclusion of older patients presenting with acute medical illness.
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Cuidados Críticos/estatística & dados numéricos , Hospitalização/estatística & dados numéricos , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Unidades de Terapia Intensiva/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , País de Gales , Adulto JovemRESUMO
BACKGROUND: Geographic and temporal trends in the distribution of PCR ribotypes for Clostridioides difficile associated diarrheal isolates obtained in the United States (US) are changing. As part of a US national surveillance program of C. difficile susceptibility to fidaxomicin, we quantified the distribution of PCR ribotypes of stool isolates collected from 2011 to 2016. METHODS: C. difficile isolates or C. difficile toxin + stools from patients with C. difficile infection (CDI) were submitted for testing to Tufts Medical Center from 6 geographically distinct medical centers. Following isolation and confirmation as C. difficile, approximately 35% of the isolates were randomly sampled, stratified by center, for PCR ribotyping by capillary gel electrophoresis. Toxin gene profiling was performed on all isolates. RESULTS: 939 isolates from a total of 2814 (33.4%) isolated over the 6 years were analyzed. Seventy unique ribotypes were observed, including 19 ribotypes observed 10 or more times. Sixteen ribotypes were not previously observed in our data base. Ribotype 027 declined by more than 60% over the 6 years of the survey from 35.3% to 13.1% (pâ¯<â¯0.001). Ribotype 106 was the most common in 2016, followed by 027 and 014-020. There were strong correlations between 027 and binary toxin with the 18 base pair deletion of tcdC and ribotype 078-126 had 100% concordance with the previously described tcdC 39 base pair deletion. CONCLUSIONS: The frequency of ribotypes in the US has changed with a marked decline in 027. Each of the geographical areas had variations which differed from each other, but collectively, these results suggest that the changing epidemiology of C. difficile in the US is consistent with what is being seen in Europe. Continued surveillance and monitoring of changes in ribotype distributions of C. difficile are warranted.
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Clostridioides difficile/isolamento & purificação , Infecções por Clostridium/epidemiologia , Ribotipagem , Toxinas Bacterianas/genética , Técnicas de Tipagem Bacteriana/métodos , Diarreia/epidemiologia , Europa (Continente)/epidemiologia , Fezes/microbiologia , Genes Bacterianos , Humanos , RNA Ribossômico/genética , Estados Unidos/epidemiologiaRESUMO
In 2011, we initiated a sentinel surveillance network to assess changes in Clostridioides (formerly Clostridium) difficile antimicrobial susceptibility to fidaxomicin from 6 geographically dispersed medical centers in the United States. This report summarizes data from 2013 to 2016. C. difficile isolates or toxin-positive stools from patients were referred to a central laboratory. Antimicrobial susceptibility was determined by agar dilution. CLSI, EUCAST, or FDA breakpoints were used, where applicable. Toxin gene profiles were characterized by multiplex PCR on each isolate. A random sample of approximately 40% of isolates, stratified by institution and year, was typed by restriction endonuclease analysis (REA). Among 1,889 isolates from 2013 to 2016, the fidaxomicin MIC90 was 0.5 µg/ml; all isolates were inhibited at ≤1 µg/ml. There were decreases in metronidazole and vancomycin MICs over time. Clindamycin resistance remained unchanged (27.3%). An increase in imipenem resistance was observed. By 2015 to 2016, moxifloxacin resistance decreased in all centers. The proportion of BI isolates decreased from 25.5% in 2011 to 2012 to 12.8% in 2015 to 2016 (P < 0.001). The BI REA group correlated with moxifloxacin resistance (BI 84% resistant versus non-BI 12.5% resistant). Fidaxomicin MICs have not changed among C. difficile isolates of U.S. origin over 5 years post licensure. There has been an overall decrease in MICs for vancomycin, metronidazole, moxifloxacin, and rifampin and an increase in isolates resistant to imipenem. Moxifloxacin resistance remained high among the BI REA group, but the proportion of BI isolates has decreased. Continued geographic variations in REA groups and antimicrobial resistance persist.
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Antibacterianos/farmacologia , Clostridioides difficile/efeitos dos fármacos , Infecções por Clostridium/microbiologia , Diarreia/microbiologia , Fidaxomicina/farmacologia , ADP Ribose Transferases/genética , Proteínas de Bactérias/genética , Toxinas Bacterianas/genética , Clindamicina/farmacologia , Clostridioides difficile/genética , Clostridioides difficile/isolamento & purificação , Farmacorresistência Bacteriana/efeitos dos fármacos , Farmacorresistência Bacteriana/genética , Enterotoxinas/genética , Humanos , Imipenem/farmacologia , Testes de Sensibilidade Microbiana , Proibitinas , Vigilância de Evento Sentinela , Estados UnidosRESUMO
Demand for critical care among older patients is increasing in many countries. Assessment of frailty may inform discussions and decision making, but acute illness and reliance on proxies for history-taking pose particular challenges in patients who are critically ill. Our aim was to investigate the inter-rater reliability of the Clinical Frailty Scale for assessing frailty in patients admitted to critical care. We conducted a prospective, multi-centre study comparing assessments of frailty by staff from medical, nursing and physiotherapy backgrounds. Each assessment was made independently by two assessors after review of clinical notes and interview with an individual who maintained close contact with the patient. Frailty was defined as a Clinical Frailty Scale rating > 4. We made 202 assessments in 101 patients (median (IQR [range]) age 69 (65-75 [60-80]) years, median (IQR [range]) Acute Physiology and Chronic Health Evaluation II score 19 (15-23 [7-33])). Fifty-two (51%) of the included patients were able to participate in the interview; 35 patients (35%) were considered frail. Linear weighted kappa was 0.74 (95%CI 0.67-0.80) indicating a good level of agreement between assessors. However, frailty rating differed by at least one category in 47 (47%) cases. Factors independently associated with higher frailty ratings were: female sex; higher Acute Physiology and Chronic Health Evaluation II score; higher category of pre-hospital dependence; and the assessor having a medical background. We identified a good level of agreement in frailty assessment using the Clinical Frailty Scale, supporting its use in clinical care, but identified factors independently associated with higher ratings which could indicate personal bias.
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Cuidados Críticos/métodos , Fragilidade/diagnóstico , Avaliação Geriátrica/métodos , Idoso , Idoso de 80 Anos ou mais , Estado Terminal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reprodutibilidade dos Testes , Escócia , Índice de Gravidade de Doença , País de GalesRESUMO
Across three experiments, we examined the cuing properties of metric (distance and direction) and nonmetric (lighting) cues in different tasks. In Experiment 1, rats were trained on a response problem in a T-maze, followed by four reversals. Rats that experienced a change in maze orientation (Direction group) or a change in the length of the start arm (Distance group) across reversals showed facilitation of reversal learning relative to a group that experienced changes in room lighting across reversals. In Experiment 2, rats learned a discrimination task more readily when distance or direction cues were used than when light cues were used as the discriminative stimuli. In Experiment 3, performance on a go/no-go task was equivalent using both direction and lighting cues. The successful use of both metric and nonmetric cues in the go/no-go task indicates that rats are sensitive to both types of cues and that the usefulness of different cues is dependent on the nature of the task.
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Percepção de Distância , Iluminação , Reversão de Aprendizagem , Percepção Espacial , Animais , Comportamento de Escolha , Sinais (Psicologia) , Aprendizagem por Discriminação , Masculino , Aprendizagem em Labirinto , Orientação , RatosRESUMO
PURPOSE: To investigate the incidence, nature and risk factors for patient-reported alopecia in survivors of critical illness. MATERIALS AND METHODS: A multi-centre, mixed methods observational study in the intensive care units (ICU) of ten hospitals in Wales. All patients with an ICU stay of 5â¯days or more, able to give consent were included. Demographic variables and risk factors were collected. A pre-designed survey was completed at three months post-ICU discharge. Statistical analysis included numbers and percentages (categorical variables) and medians and interquartile ranges (continuous variables). Comparisons between patients with and without alopecia were made using Fisher's Exact test (categorical variables) and Mann Whitney U test (continuous variables). Multivariate logistic regression analysis was used to determine the risk factors for alopecia. RESULTS: The survey was completed by 123 patients with alopecia reported in 44 (36%) patients. The only risk factor for alopecia on analysis was sepsis / septic shock (pâ¯<â¯.001; OR: 5.1, 95%CI: 2.1-12.4). CONCLUSIONS: Limited research exists examining the incidence, nature and risk factors for patient-reported alopecia in adult survivors of critical illness. The results of this study highlight the need to discuss the potential for alopecia with survivors of critical illness, who had sepsis / septic shock.
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Alopecia/etiologia , Sepse/complicações , Sobreviventes , Idoso , Alopecia/fisiopatologia , Alopecia/psicologia , Estado Terminal , Feminino , Humanos , Incidência , Unidades de Terapia Intensiva/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Sepse/fisiopatologia , Sobreviventes/psicologiaRESUMO
AIM: To develop a novel validated method for the isolation of Bifidobacterium animalis ssp. lactis BB-12 (BB-12) from faecal specimens and apply it to studies of BB-12 and Lactobacillus rhamnosus GG (LGG) recovered from the healthy human gastrointestinal (GI) tract. METHODS AND RESULTS: A novel method for isolating and enumerating BB-12 was developed based on its morphologic features of growth on tetracycline-containing agar. The method identified BB-12 correctly from spiked stool close to 100% of the time as validated by PCR confirmation of identity, and resulted in 97-104% recovery of BB-12. The method was then applied in a study of the recovery of BB-12 and LGG from the GI tract of healthy humans consuming ProNutrients® Probiotic powder sachet containing BB-12 and LGG. Viable BB-12 and LGG were recovered from stool after 21 days of probiotic ingestion compared to baseline. In contrast, no organisms were recovered 21 days after baseline in the nonsupplemented control group. CONCLUSIONS: We demonstrated recovery of viable BB-12, using a validated novel method specific for the isolation of BB-12, and LGG from the GI tract of healthy humans who consumed the probiotic supplement. SIGNIFICANCE AND IMPACT OF THE STUDY: This method will enable more detailed and specific studies of BB-12 in probiotic supplements, including when in combination with LGG.
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Bifidobacterium animalis/isolamento & purificação , Trato Gastrointestinal/microbiologia , Lacticaseibacillus rhamnosus/fisiologia , Probióticos/administração & dosagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos , Bifidobacterium animalis/classificação , Bifidobacterium animalis/genética , Bifidobacterium animalis/fisiologia , Suplementos Nutricionais , Fezes/microbiologia , Feminino , Voluntários Saudáveis , Humanos , Lacticaseibacillus rhamnosus/genética , Lacticaseibacillus rhamnosus/isolamento & purificação , Masculino , Pessoa de Meia-Idade , Tetraciclina , Adulto JovemRESUMO
Advancing age is a well-known risk factor for tendon disease. Energy-storing tendons [e.g., human Achilles, equine superficial digital flexor tendon (SDFT)] are particularly vulnerable and it is thought that injury occurs following an accumulation of micro-damage in the extracellular matrix (ECM). Several authors suggest that age-related micro-damage accumulates due to a failure of the aging cell population to maintain the ECM or an imbalance between anabolic and catabolic pathways. We hypothesized that ageing results in a decreased ability of tendon cells to synthesize matrix components and matrix-degrading enzymes, resulting in a reduced turnover of the ECM and a decreased ability to repair micro-damage. The SDFT was collected from horses aged 3-30 years with no signs of tendon injury. Cell synthetic and degradative ability was assessed at the mRNA and protein levels. Telomere length was measured as an additional marker of cell ageing. There was no decrease in cellularity or relative telomere length with increasing age, and no decline in mRNA or protein levels for matrix proteins or degradative enzymes. The results suggest that the mechanism for age-related tendon deterioration is not due to reduced cellularity or a loss of synthetic functionality and that alternative mechanisms should be considered.
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Envelhecimento/metabolismo , Matriz Extracelular/fisiologia , Metaloproteinases da Matriz/metabolismo , Fragmentos de Peptídeos/biossíntese , Pró-Colágeno/biossíntese , Tendões/citologia , Tendões/metabolismo , Proteína ADAM12/genética , Proteína ADAM17/genética , Proteínas ADAMTS/genética , Envelhecimento/patologia , Animais , DNA/metabolismo , Cavalos , Metaloproteinases da Matriz/genética , RNA Mensageiro/metabolismo , Encurtamento do Telômero , Tendões/enzimologia , Inibidor Tecidual de Metaloproteinase-3/genética , Inibidores Teciduais de Metaloproteinases/genética , Inibidor Tecidual 4 de MetaloproteinaseRESUMO
In 2011 a surveillance study for the susceptibility to fidaxomicin and epidemiology of Clostridium difficile isolates in the United States was undertaken in seven geographically dispersed medical centers. This report encompasses baseline surveillance in 2011 and 2012 on 925 isolates. A convenience sample of C. difficile isolates or toxin positive stools from patients were referred to a central laboratory. Antimicrobial susceptibility was determined by agar dilution (CLSI M11-A8). Clinical and Laboratory Standards Institute (CLSI), Food and Drug Administration, or European Union of Clinical Antimicrobial Susceptibility Testing (EUCAST) breakpoints were applied where applicable. Toxin gene profiles were characterized by multiplex PCR on each isolate. A random sample of 322 strains, stratified by institution, underwent restriction endonuclease analysis (REA). The fidaxomicin MIC90 was 0.5 µg/ml for all isolates regardless of REA type or toxin gene profile, and all isolates were inhibited at ≤1.0 µg/ml. By REA typing, BI strains represented 25.5% of the isolates. The toxin gene profile of tcdA, tcdB, and cdtA/B positive with a tcdC 18-bp deletion correlated with BI REA group. Moxifloxacin and clindamycin resistance was increased among either BI or binary toxin-positive isolates. Metronidazole and vancomycin showed reduced susceptibility (EUCAST criteria) in these isolates. Geographic variations in susceptibility, REA group and binary toxin gene presence were observed. Fidaxomicin activity against C. difficile isolated in a national surveillance study did not change more than 1 year after licensure. This analysis provides baseline results for future comparisons.
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Aminoglicosídeos/farmacologia , Antibacterianos/farmacologia , Clostridioides difficile/efeitos dos fármacos , Diarreia/epidemiologia , Enterocolite Pseudomembranosa/epidemiologia , Genes Bacterianos , Vigilância de Evento Sentinela , Toxinas Bacterianas/genética , Toxinas Bacterianas/imunologia , Toxinas Bacterianas/isolamento & purificação , Clindamicina/farmacologia , Clostridioides difficile/genética , Clostridioides difficile/isolamento & purificação , Diarreia/tratamento farmacológico , Diarreia/microbiologia , Farmacorresistência Bacteriana/genética , Enterocolite Pseudomembranosa/tratamento farmacológico , Enterocolite Pseudomembranosa/microbiologia , Fidaxomicina , Fluoroquinolonas/farmacologia , Humanos , Metronidazol/farmacologia , Testes de Sensibilidade Microbiana , Moxifloxacina , Reação em Cadeia da Polimerase Multiplex , Proibitinas , Estados Unidos/epidemiologia , Vancomicina/farmacologiaRESUMO
Tendon injury is thought to involve both damage accumulation within the matrix and an accompanying cell response. While several studies have characterized cell and matrix response in chronically injured tendons, few have assessed the initial response of tendon to overload-induced damage. In this study, we assessed cell response to cyclic loading. Fascicle bundles from the equine superficial digital flexor tendon were exposed to cyclic loading in vitro, designed to mimic a bout of high-intensity exercise. Changes in cell morphology and protein-level alterations in markers of matrix inflammation and degradation were investigated. Loading resulted in matrix damage, which was accompanied by cells becoming rounder. The inflammatory markers cyclooxygenase-2 and interleukin-6 were increased in loaded samples, as were matrix metalloproteinase-13 and the collagen degradation marker C1,2C. These results indicate upregulation of inflammatory and degradative pathways in response to overload-induced in vitro, which may be initiated by alterations in cell strain environment because of localized matrix damage. This provides important information regarding the initiation of tendinopathy, suggesting that inflammation may play an important role in the initial cell response to tendon damage. Full understanding of the early tenocyte response to matrix damage is critical in order to develop effective treatments for tendinopathy.