Impact Of Antimicrobial Therapy Research Articles

Interpreting and managing preservation fluids positive for Gram-negative bacteria.

Culturing preservation fluids of solid organs before transplantation is not a standardized procedure. In this review, we aim to describe the state-of-the-art of literature evidence in this debated setting with a special focus on Gram-negative bacteria (GNB). Contamination of preservation fluids is frequent, but preservation fluids related infections are rare and most commonly caused by high-risk pathogens, including GNB. GNB preservation fluids related infections are characterized by high morbidity and mortality. Recent studies showed improved outcomes in solid organ transplant recipients receiving antibiotic therapy tailored according to preservation fluids cultures especially when multidrug-resistant GNB are found. A robust procurement network is needed to alert recipients' centers in cases of positivity and the support of transplant infectious diseases specialists is essential to choose the best therapy. Culturing preservation fluids is a further step into preventing donor-derived infections. Interpreting and managing GNB positivity require a multidisciplinary team with specific skills. Standardized randomized trials are needed for insight into the real utility of preservation fluids cultures, the role of preservation fluids positivity, and the impact of antimicrobial therapy.

Impact of Amoxicillin treatment on E. coli in dairy cow faeces

Introduction: There has been a global drive for increased antimicrobial stewardship. In the UK, this drive has focused on decreased usage of antimicrobials, specifically HP-CIAs. It is well known that antimicrobials are selection drivers for antimicrobial resistance. How a given dose will impact the prevalence of resistance in a microbiome, and therefore the associated risk of a resistant infection is less understood. Questions also remain around the impact of antimicrobial therapy on resistance across a herd, if selection occurs within an animal receiving treatment, what is the potential risk of this resistance spreading throughout other animals? Methods: E. COLI ISOLATION Tryptone Bile X-Glucuronide (TBX) media was used for selective growth of non – toxigenic E. coli from dairy cow faeces. SUSCEPTIBILITY TESTING EUCAST Disk Diffusion testing guidelines were followed to determine susceptibility of faecal isolates to a panel of 8 antimicrobials from 5 different classes. ISOLATE FINGERPRINTING To determine clonality of faecal isolates ERIC-PCR was used as an efficient method to provide a genomic fingerprint. Results This work is ongoing. Current work suggests that low frequency Amoxicillin treatment has no significant selection for resistance. However, there appears to be some instances of co-selection for Streptomycin, Tetracycline and Sulphonamide resistance, and several multi drug resistance isolates have been identified. More work needs to be done to confirm the impact of low frequency Amoxicillin treatment on E. coli resistance and identify the mechanism behind suspected co-selection and multi drug resistance.

Variability in the Management of Adults With Pulmonary Nontuberculous Mycobacterial Disease.

The increasing global prevalence of pulmonary nontuberculous mycobacteria (NTM) disease has called attention to challenges in NTM diagnosis and management. This study was conducted to understand management and outcomes of patients with pulmonary NTM disease at diverse centers across the United States. We conducted a 10-year (2005-2015) retrospective study at 7 Vaccine and Treatment Evaluation Units to evaluate pulmonary NTM treatment outcomes in human immunodeficiency virus-negative adults. Demographic and clinical information was abstracted through medical record review. Microbiologic and clinical cure were evaluated using previously defined criteria. Of 297 patients diagnosed with pulmonary NTM, the most frequent NTM species were Mycobacterium avium-intracellulare complex (83.2%), M. kansasii (7.7%), and M. abscessus (3.4%). Two hundred forty-five (82.5%) patients received treatment, while 45 (15.2%) were followed without treatment. Eighty-six patients had available drug susceptibility results; of these, >40% exhibited resistance to rifampin, ethambutol, or amikacin. Of the 138 patients with adequate outcome data, 78 (56.5%) experienced clinical and/or microbiologic cure. Adherence to the American Thoracic Society/Infectious Diseases Society of America (ATS/IDSA) treatment guidelines was significantly more common in patients who were cured (odds ratio, 4.5, 95% confidence interval, 2.0-10.4; P < .001). Overall mortality was 15.7%. Despite ATS/IDSA Guidelines, management of pulmonary NTM disease was heterogeneous and cure rates were relatively low. Further work is required to understand which patients are suitable for monitoring without treatment and the impact of antimicrobial therapy on pulmonary NTM morbidity and mortality.

Impact of antimicrobial therapy on the gut microbiome.

The gut microbiome is now considered an organ unto itself and plays an important role in health maintenance and recovery from critical illness. The commensal organisms responsible for the framework of the gut microbiome are valuable in protection against disease and various physiological tasks. Critical illness and the associated interventions have a detrimental impact on the microbiome. While antimicrobials are one of the fundamental and often life-saving modalities in septic patients, they can also pave the way for subsequent harm because of the resulting damage to the gut microbiome. Contributing to many of the non-specific signs and symptoms of sepsis, the balance between the overuse of antimicrobials and the clinical need in these situations is often difficult to delineate. Given the potency of antimicrobials utilized to treat septic patients, the effects on the gut microbiome are often rapid and long-lasting, in which case full recovery may never be observed. The overgrowth of opportunistic pathogens is of significant concern as they can lead to infections that become increasingly difficult to treat. Continued research to understand the disturbances within the gut microbiome of critically ill patients and their outcomes is essential to help develop future therapies to circumvent damage to, or restore, the microbiome. In this review, we discuss the impact of the antimicrobials often used for the treatment of sepsis on the gut microbiota.

Impact of Antimicrobial Therapy on the Semen Parameters of Infertile Men With Asymptomatic Urogenital Microorganism

Impact of Antimicrobial Therapy on the Semen Parameters of Infertile Men With Asymptomatic Urogenital Microorganism

Risk factors and antibiotic therapy in P. aeruginosa community-acquired pneumonia.

Current guidelines recommend empirical treatment against Pseudomonas aeruginosa in community-acquired pneumonia (CAP) patients with specific risk factors. However, evidence to support these recommendations is limited. We evaluate the risk factors and the impact of antimicrobial therapy in patients hospitalized with CAP due to P. aeruginosa. We performed a retrospective population-based study of >150 hospitals. Patients were included if they had a diagnosis of CAP and P. aeruginosa was identified as the causative pathogen. Univariate and multivariate analyses were performed using the presence of risk factors and 30-day mortality as the dependent measures. Seven hundred eighty-one patients with P. aeruginosa pneumonia were identified in a cohort of 62 689 patients with pneumonia (1.1%). Of these, 402 patients (0.6%) were included in the study and 379 (0.5%) were excluded due to health care-associated pneumonia or immunosuppression. In patients with CAP due to P. aeruginosa, 272 (67.8%) had no documented risk factors. These patients had higher rates of dementia and cerebrovascular disease. Empirical antibiotic therapy against P. aeruginosa within the first 48 h of presentation was independently associated with lower 30-day mortality in patients with CAP due to P. aeruginosa (hazard ratio (HR) 0.42, 95% confidence interval (CI): 0.23-0.76) and in patients without risk factors for P. aeruginosa CAP (HR 0.40, 95% CI: 0.21-0.76). Risk factor recommended by current guidelines only detect one third of the patients admitted with CAP due to P. aeruginosa. Risk factors did not define the whole benefit observed due to empirical therapy covering P. aeruginosa.

Impact of Cefepime Therapy on Mortality among Patients with Bloodstream Infections Caused by Extended-Spectrum-β-Lactamase-Producing Klebsiella pneumoniae and Escherichia coli

Extended-spectrum-β-lactamase (ESBL)-producing pathogens are associated with extensive morbidity and mortality and rising health care costs. Scant data exist on the impact of antimicrobial therapy on clinical outcomes in patients with ESBL bloodstream infections (BSI), and no large studies have examined the impact of cefepime therapy. A retrospective 3-year study was performed at the Detroit Medical Center on adult patients with BSI due to ESBL-producing Klebsiella pneumoniae or Escherichia coli. Data were collected from the medical records of study patients at five hospitals between January 2005 and December 2007. Multivariate analysis was performed using logistic regression. One hundred forty-five patients with BSI due to ESBL-producing pathogens, including K. pneumoniae (83%) and E. coli (16.5%), were studied. The mean age of the patients was 66 years. Fifty-one percent of the patients were female, and 79.3% were African-American. Fifty-three patients (37%) died in the hospital, and 92 survived to discharge. In bivariate analysis, the variables associated with mortality (P < 0.05) were presence of a rapidly fatal condition at the time of admission, use of gentamicin as a consolidative therapeutic agent, and presence of one or more of the following prior to culture date: mechanical ventilation, stay in the intensive care unit (ICU), and presence of a central venous catheter. In multivariate analysis, the predictors of in-hospital mortality included stay in the intensive care unit (odds ratio [OR], 2.17; 95% confidence interval [CI], 0.98 to 4.78), presence of a central-line catheter prior to positive culture (OR, 2.33; 95% CI, 0.77 to 7.03), presence of a rapidly fatal condition at the time of admission (OR, 5.13; 95% CI, 2.13 to 12.39), and recent prior hospitalization (OR, 1.92; 95% CI, 0.83 to 4.09). When carbapenems were added as empirical therapy to the predictor model, there was a trend between empirical carbapenem therapy and decreased mortality (OR, 0.61; 95% CI, 0.26 to 1.50). When added to the model, receipt of empirical cefepime alone (n = 43) was associated with increased mortality, although this association did not reach statistical significance (OR, 1.66; 95% CI, 0.71 to 3.87). The median length of hospital stay was shorter for patients receiving empirical cefepime than for those receiving empirical or consolidated carbapenem therapy. In multivariate analysis, empirical therapy with cefepime for BSI due to an ESBL-producing pathogen was associated with a trend toward an increased mortality risk and empirical carbapenem therapy was associated with a trend toward decreased mortality risk.

Diagnostic Value of Bronchoalveolar Lavage in Leukemic and Bone Marrow Transplant Patients: The Impact of Antimicrobial Therapy

PURPOSE: Bronchoalveolar lavage (BAL) is effective in diagnosing infectious causes of pulmonary infiltrates particularly in immunocompromised patients. Leukemic and bone marrow transplant (BMT) patients are at increased risk for pneumonia and are usually on multiple antimicrobials at the time of bronchoscopy. We queried the yield of bronchoscopy in this population hypothesizing that antimicrobial treatment decreases the diagnostic yield of BAL.

Impact of multidrug-resistant Pseudomonas aeruginosa infection on patient outcomes

Rates of antibiotic resistance in Pseudomonas aeruginosa are increasing worldwide. The multidrug-resistant (MDR) phenotype in P. aeruginosa could be mediated by several mechanisms including multidrug efflux systems, enzyme production, outer membrane protein (porin) loss and target mutations. Currently, no international consensus on the definition of multidrug resistance exists, making direct comparison of the literature difficult. Inappropriate empirical therapy has been associated with increased mortality in P. aeruginosa infections; delays in starting appropriate therapy may contribute to increased length of hospital stay and persistence of infection. In addition, worse clinical outcomes may be associated with MDR infections owing to limited effective antimicrobial options. This article aims to summarize the contemporary literature on patient outcomes following infections caused by drug-resistant P. aeruginosa. The impact of antimicrobial therapy on patient outcomes, mortality and morbidity; and the economic impact of MDR P. aeruginosa infections will be examined.

Bloodstream infection due to Acinetobacter spp: epidemiology, risk factors and impact of multi-drug resistance

Acinetobacter spp. are increasingly reported as important causes of human infection. Many isolates exhibit multi-drug resistance, raising concerns over our ability to treat serious infections with these organisms. The impact of infection on clinical outcome as well as the importance of multi-drug resistance is poorly defined. A descriptive retrospective observational study was undertaken of all episodes of Acinetobacter bacteremia occurring in a UK tertiary care centre from 1998-2006. Demographics of infected patients, characteristics and antimicrobial susceptibility of infecting strains were recorded and the impact of antimicrobial therapy on all causes of 30-day mortality assessed. Three hundred ninety-nine episodes of Acinetobacter bacteremia were identified, with A. baumannii being the most frequently isolated species. Most episodes occurred in critical care and were associated with multidrug resistance, with carbapenem resistance rising from 0% in 1998 to 55% in 2006. Although bacteremia due to carbapenem-resistant Acinetobacter and a requirement for critical care were associated with a higher mortality, mortality was not reduced by the administration of appropriate empirical antimicrobial therapy. A prospective study is required to identify both the most effective intervention and those most likely to benefit from treatment.

Analysis of 1,186 Episodes of Gram-Negative Bacteremia in Non-University Hospitals: The Effects of Antimicrobial Therapy

Over the five-year period 1977-1981, we studied 1,186 episodes of bacteremia due to Enterobacteriaceae and Pseudomonadaceae in the four non-university hospitals of a single metropolitan area. Overall patient mortality was 36.3%, and mortality attributed specifically to infection was 19.0%. The importance of severity of underlying disease, site of infection, microorganism, and age--previously determined to be prognostic factors in studies conducted at tertiary-care centers--was confirmed. Appropriate initial antimicrobial therapy (defined as the administration of an effective agent in adequate dose and by a suitable route of administration on the first calendar day on which blood cultures were positive) did not improve survival compared with the use of an ineffective antimicrobial agent or no therapy at all. However, appropriate antimicrobial therapy subsequent to the first calendar day on which blood cultures were positive clearly affected survival. These findings confirm previous conclusions regarding the frequency and severity of gram-negative bacteremia and the overall impact of antimicrobial therapy on this condition. These studies also suggest the possibility that the definition of optimal initial therapy in some groups of patients should be reconsidered.