Selection Of Appropriate Empiric Therapy Research Articles

Antimicrobial susceptibility patterns of community-acquired uropathogenic Escherichia coli, Dublin 2010-2022.

Escherichia coli is a common cause of urinary tract infections. Due to the increase in antimicrobial resistance (AMR) and global differences in antimicrobial susceptibility data, routine assessment of local antimicrobial susceptibility patterns is necessary to guide the selection of appropriate empirical therapy. The aim of this study was to evaluate the antimicrobial susceptibility patterns of community-acquired uropathogenic Escherichia coli within a catchment area in Dublin over a 13 year period, 2010-2022. All mid-stream urine samples received from local general practitioners in which there was significant E. coli bacteriuria during the study period, 2010-2022, were included in the analysis. Antimicrobial susceptibility testing was performed by disc diffusion as per the European Committee on Antimicrobial Susceptibility Testing recommendations. An average of 11 407 urine samples per month had significant bacteriuria, with E. coli accounting for an average of 67 % of those. Overall AMR rates were highest for ampicillin (53.9 %), followed by trimethoprim (32.4 %), gentamicin (18.6 %), co-amoxiclav (16.5 %), ciprofloxacin (12.3 %), cephalexin (8.3 %), cefpodoxime (6.8 %) and nitrofurantoin (2 %). While rates appeared grossly static, statistically significant reduced resistance rates were noted for co-amoxiclav (rs=-0.95; P=<0.001), cephalexin prior to 2019 (rs=-0.783; P=0.013) and trimethoprim (rs=-0.639; P=0.019), with a statistically significant increase in non-susceptibility to cefpodoxime (rs=0.802; P=0.001). In order to generate efficient empirical antimicrobial prescribing guidelines, knowledge of region-specific contemporaneous antimicrobial susceptibility patterns is pivotal. Our findings support the use of nitrofurantoin or cephalexin as empirical antimicrobial therapy within our setting.

Changing Trends of Candida Species and Antifungal Susceptibility Profile of Candida Bloodstream Isolates: A 5-Year Retrospective Survey

Background: Candida species have emerged as one of the most common causes of bloodstream infections (BSIs). There are limited data on the distribution of Candida spp. and susceptibility by year. Objectives: In this study, we analyzed changes in the distribution of Candida spp. and their antifungal susceptibility profiles from blood cultures. Methods: Records from January 2016 to December 2020 were obtained from the microbiology laboratory in Istanbul. Antifungal susceptibility tests were performed using the VITEK 2 compact system and evaluated according to EUCAST breakpoints. A total of 241 unique candidemia episodes were included in this study. Results: Candida albicans was the predominant pathogen (n = 95, 39.42%), followed by C. parapsilosis (n = 82, 34.02%), C. glabrata (n = 18, 7.47%), C. tropicalis (n = 17, 7.05%), C. krusei (n = 15, 6.22%), and other Candida spp. (n = 14, 5.79%). There was no statistically significant difference in the percentage of episodes of Candida spp. After data analysis, a tendency to shift from C. albicans to C. parapsilosis was observed in the period analyzed in this study. Candida albicans was the most common species in intensive care units (ICUs), hematology and hemopoietic stem cell transplantation units, and surgical clinics, with C. parapsilosis predominant in medical clinics. In general, micafungin susceptibility was the highest, and fluconazole was the lowest. There was reduced sensitivity to fluconazole and voriconazole for C. albicans and C. parapsilosis over 5 years. Conclusions: Detecting changes in the distribution of Candida spp. and antifungal susceptibility over time will lead to the selection of appropriate empirical therapy and monitor phenomena of antifungal resistance. Empirical treatment with antifungal agents is associated with high costs, toxicities, and risk of antifungal resistance. Therefore, it is mandatory to determine and monitor Candida spp. and antifungal susceptibility testing to select appropriate antifungal agents.

Characterization of Neonatal Infections by Gram-Negative Bacilli and Associated Risk Factors, Havana, Cuba.

Infections represent an important problem in neonates because of the high mortality. An increase in neonatal infections has been found in Cuban hospitals in recent years. The aim of this study was to provide evidence on the clinical and microbiological behavior of Gram-negative bacilli that cause neonatal infections in hospitals of Havana, Cuba. It was carried out as a descriptive cross-sectional investigation from September 2017 to July 2018 in The Tropical Medicine Institute “Pedro Kouri” (IPK). Sixty-one Gram-negative bacilli isolated from neonates with infections in six Gyneco-Obstetric and Pediatric Hospitals of Havana were analyzed for their species and antimicrobial susceptibility. Late-onset infections were more common than early-onset ones and included urinary tract infection in the community (87%) and sepsis in hospitals (63.3%). Catheter use (47%) and prolonged stay (38%) were the most frequent risk factors. Species of major pathogens were Escherichia coli (47%) and Klebsiella spp. (26%). The isolated Gram-negative bacilli showed high resistance rates to third-generation cephalosporins, ciprofloxacin and gentamicin, while being more susceptible to carbapenems, fosfomycin, colistin and amikacin. The present study revealed the clinical impact of Gram-negative bacilli in neonatology units in hospitals of Havana. Evaluation of antimicrobial susceptibilities to the isolates from neonates is necessary for selection of appropriate empirical therapy and promotion of the rational antibiotic use.

Non-tuberculous mycobacteria profiles and their anti-mycobacterial resistance at a major medical center in Lebanon

Infection with non-tuberculosis mycobacteria (NTM) has been on the rise globally causing a wide spectrum of respiratory and extrapulmonary infections in humans. Studies on these pathogens from the Middle-East including Lebanon are scarce. This retrospective study addresses the approach used for investigation, speciation and antimicrobial resistance (AMR) profiles of recovered NTM isolates from respiratory sources at a major tertiary care center in Lebanon during two periods (2003-2007 and 2013-2017). Processing of specimens, culture and differentiation of recovered NTM isolates from Mycobacterium tuberculosis were done in-house according to standard procedures. Upon request, speciation and AMR testing were performed using molecular and broth dilution methods, respectively, at Mayo Medical Laboratories (Rochester, Minnesota, USA). Among 108 NTM analyzed isolates, 8 species were revealed during the two periods: M. simiae (51% vs 61%), M. avium complex (MAC) (6 % vs 12%) M. fortuitum (12% vs 5%), M. gordonae (6% vs 5%), M. abscessus (6% vs 7%), M. immunogenum (12% vs 0%), M. szulgai (4% vs 0%) and M. peregrinum (0% vs 2%). M. simiae isolates showed high susceptibility (93%-96%) to amikacin and clarithromycin, but high resistance to rifampin, ethambutol, ciprofloxacin, rifabutin, linezolid, trimethoprim/sulfamethoxazole and moxifloxacin. MAC isolates were only susceptible to clarithromycin (86%). M. abscessus isolates were uniformly susceptible to amikacin (100%). The revelaed different NTM species, with predominance of M.simiae and various AMR profiles provide a current epidemiologic database and help guiding the selection of appropriate empirical therapy once the clinical relevance is established.

Urosepsis Due to Extended-Spectrum ß-Lactamase–Producing Escherichia coli: A Retrospective, Single-Centre Review of Risk Factors and Clinical Outcomes

Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae are pathogens that are implicated in urosepsis and may be associated with greater morbidity and mortality than non-ESBL Enterobacteriaceae. Identification of risk factors for ESBL infection may facilitate the selection of appropriate empiric therapy. The primary objectives were to determine the cumulative incidence of ESBL urosepsis, to identify major risk factors for ESBL urosepsis, and to determine the impact of international travel on development of ESBL urosepsis in an ethnically diverse Canadian population. The secondary objective was to characterize the outcomes of patients with ESBL urosepsis. A single-centre retrospective nested case-control study was conducted from January 2011 to June 2013. The study cohort consisted of adult patients with urosepsis and positive results on blood culture for ESBL-producing and non-ESBL-producing Enterobacteriaceae. Multivariate analysis was then used to determine risk factors for ESBL urosepsis. The cumulative incidence of ESBL urosepsis at the study site was 19.4% (58/299) over 2.5 years. The 58 cases of ESBL urosepsis were compared with 118 controls (patients with urosepsis caused by non-ESBL Enterobacteriaceae). Significant predictors of ESBL urosepsis were chronic renal insufficiency (odds ratio [OR] 4.66, 95% confidence interval [CI] 1.96-11.08; p < 0.001) and travel to an endemic region in the previous 6 months (OR 4.62, 95% CI 1.17-18.19; p = 0.029), as well as Punjabi or Hindi as the primary language (OR 3.25, 95% CI 1.45-7.29; p = 0.004) and male sex (OR 2.65, 95% CI 1.21-5.80; p = 0.015). Patients with ESBL urosepsis had worse prognosis-in terms of death or discharge with palliative measures only-than those with non-ESBL urosepsis (7/58 [12.1%] versus 4/118 [3.4%]; p = 0.042). Institution-specific data support prompt recognition of patients at risk for ESBL infections. Chronic renal insufficiency, recent travel to regions endemic for ESBL-producing organisms, primary language of Punjabi or Hindi, and male sex were the strongest risk factors for ESBL urosepsis at the study centre. However, findings from this single-centre study may not be generalizable to other institutions.

Anaerobic Bacteria in Clinical Specimens - Frequent, But a Neglected Lot: A Five Year Experience at a Tertiary Care Hospital.

Anaerobic bacteria which constitute a significant proportion of the normal microbiota also cause variety of infections involving various anatomic sites. Considering the tedious culture techniques with longer turnaround time, anaerobic cultures are usually neglected by clinicians and microbiologists. To study the frequency of isolation of different anaerobic bacteria from various clinical specimens. A retrospective study to analyse the frequency of isolation of different anaerobic bacteria, was conducted over a period of five years from 2011 to 2015 including various clinical specimens submitted to anaerobic division of Microbiology laboratory. Anaerobic bacteria were isolated and identified following standard bacteriological techniques. Pathogenic anaerobes (n=336) were isolated from 278 (12.48%) of overall 2227 specimens processed with an average yield of 1.2 isolates. Anaerobes were isolated as polymicrobial flora with or without aerobic bacterial pathogens in 159 (57.2%) patients. Anaerobic Gram-negative bacilli (140, 41.7%) were the predominant isolates. B. fragilis group (67, 19.9%) were the most commonly isolated anaerobic pathogens. Anaerobes were predominantly isolated from deep seated abscess (23.9%). Pathogenic anaerobes were isolated from various infection sites. Unless culture and susceptibility tests are performed as a routine, true magnitude of antimicrobial resistance among anaerobic pathogens will not be known. Knowledge of the distribution of these organisms may assist in the selection of appropriate empirical therapy for anaerobic infections.

Clinical and Microbiologic Characteristics of Cephalosporin-Resistant Escherichia coli at Three Centers in the United States

We investigated the clinical and microbiologic features of 300 cases of cephalosporin-resistant Escherichia coli producing extended-spectrum β-lactamase (ESBL) or plasmid-mediated AmpC β-lactamase (pAmpC) at three medical centers in the United States. Solid-organ malignancy, connective tissue disease, and a recent history of surgery were more common among pAmpC-producing cases (n = 49), whereas urinary catheter at enrollment, diabetes, and hospitalization in the past year were more common among ESBL-producing cases (n = 233). The factors independently associated with clinical outcome were the following: the presence of cardiovascular disease (odds ratio [OR], 2.88; 95% confidence interval [CI], 1.29 to 6.43), intra-abdominal infection (OR, 6.35; 95% CI, 1.51 to 26.7), other or multiples sources of infection (OR, 8.12; 95% CI, 2.3 to 28.6), age of 65 years or greater (OR, 0.43; 95% CI, 0.2 to 0.95), favorable baseline health status (OR, 0.39; 95% CI, 0.16 to 0.95), and appropriate empirical antimicrobial therapy given in the first 72 h (OR, 0.42; 95% CI, 0.20 to 0.88). β-Lactamase genes responsible for cephalosporin resistance were identified in 291 cases. CTX-M-type ESBLs accounted for 72.0%. Of those, 88.0% were CTX-M-15. The next most common type was CMY-type pAmpC (16.7%), followed by SHV- and TEM-type ESBLs (6.3 and 1.3%, respectively). Seven cases (2.3%) had KPC-type β-lactamase. Ertapenem, imipenem, meropenem, doripenem, piperacillin-tazobactam, amikacin, nitrofurantoin, and tigecycline were highly active, with greater than 90% of the isolates being susceptible. Cefepime was less active, with only 74.2% being susceptible due to the predominance of CTX-M-15. These findings have implications in the selection of appropriate empirical therapy when infection due to cephalosporin-resistant E. coli is suspected.

Role of Unit-Specific Combination Antibiograms for Improving the Selection of Appropriate Empiric Therapy for Gram-Negative Pneumonia

In an effort to improve the selection of appropriate empiric gram-negative therapy for pneumonia, we examined intensive care unit-specific combination antibiograms. These antibiograms were able to predict appropriate empiric gram-negative therapy. Empiric combination therapy based on unit-specific combination antibiograms may aid in the selection of therapy for gram-negative pneumonia.

Impact of Multidrug-Resistant Pseudomonas aeruginosa Bacteremia on Patient Outcomes

Trends of rising rates of resistance in Pseudomonas aeruginosa make selection of appropriate empirical therapy increasingly difficult, but whether multidrug-resistant (MDR) P. aeruginosa is associated with worse clinical outcomes is not well established. The objective of this study was to determine the impact of MDR (resistance to three or more classes of antipseudomonal agents) P. aeruginosa bacteremia on patient outcomes. We performed a retrospective cohort study of adult patients with P. aeruginosa bacteremia from 2005 to 2008. Patients were identified by the microbiology laboratory database, and pertinent clinical data were collected. Logistic regression was used to explore independent risk factors for 30-day mortality. Classification and regression tree analysis was used to determine threshold breakpoints for continuous variables. Kaplan-Meier survival analysis was used to compare time to mortality, after normalization of the patients' underlying risks by propensity scoring. A total of 109 bacteremia episodes were identified; 25 episodes (22.9%) were caused by MDR P. aeruginosa. Patients with MDR P. aeruginosa bacteremia were more likely to receive inappropriate empirical therapy (44.0% and 6.0%, respectively; P < 0.001) and had longer prior hospital stays (32.6 +/- 37.3 and 14.4 +/- 43.6 days, respectively; P = 0.046). Multivariate regression revealed that 30-day mortality was associated with multidrug resistance (odds ratio [OR], 6.8; 95% confidence interval [CI], 1.9 to 24.0), immunosuppression (OR, 5.0; 95% CI, 1.4 to 17.5), and an APACHE II score of > or = 22 (OR, 29.0; 95% CI, 5.0 to 168.2). Time to mortality was also shorter in the MDR cohort (P = 0.011). Multidrug resistance is a significant risk factor for 30-day mortality in patients with P. aeruginosa bacteremia; efforts to curb the spread of MDR P. aeruginosa could be beneficial.

Clinical Consensus Conference: Survey on Gram‐Positive Bloodstream Infections with a Focus onStaphylococcus aureus

The increased incidence over the past decade of bloodstream infections (BSIs) caused by gram-positive bacteria, particularly methicillin-resistant Staphylococcus aureus, highlights the critical need for a consistent approach to therapy. However, there is currently no international consensus on the diagnosis and management of gram-positive BSIs. The Clinical Consensus Conference on Gram-Positive Bloodstream Infections was convened as a session at the 9th International Symposium on Modern Concepts in Endocarditis and Cardiovascular Infections held in 2007. Participants discussed various aspects of the practical treatment of patients who present with gram-positive BSI, including therapeutic options for patients with BSIs of undefined origin, the selection of appropriate empirical therapy, and treatment of complicated and uncomplicated BSIs. The opinions of participants about these key issues are reflected in this article.

Per Migliorare la Guarigione di Pazienti Affetti da Infezione del Tratto Respiratorio

The common respiratory tract infections of acute bacterial sinusitis, acute exacerbation of chronic bronchitis, and community-acquired pneumonia are responsible for millions of physician office visits every year. Despite advances in diagnostic testing and the development of new antimicrobial agents, these infections continue to contribute significantly to patient morbidity and mortality worldwide. Physicians are faced with multiple challenges in the management of patients with these diseases. These challenges include the selection of appropriate empiric therapy, the increasing emergence of resistant pathogens, patient noncompliance with therapeutic regimens, and the pressure to use costeffective agents. Patients expect their antibiotics to work rapidly so that they can feel better quickly and return swiftly to their normal activities. Moxifloxacin has been developed to address many of these problems. Its efficacy has been demonstrated in an extensive clinical trial program the results of which are summarized below. The excellent pharmacokinetics and pharmacodynamics of moxifloxacin are covered elsewhere in this supplement, as is moxifloxacin's impressive safety and tolerability profile. Accordingly, this paper focuses on the clinical trial data currently available.