Clinical profiles of patients colonized or infected with extended-spectrum beta-lactamase producing Enterobacteriaceae isolates: a 20 month retrospective study at a Belgian University Hospital

<p>Abstract</p> <p>Background</p> <p>Description of the clinical pictures of patients colonized or infected by ESBL-producing <it>Enterobacteriaceae </it>isolates and admitted to hospital are rather scarce in Europe. However, a better delineation of the clinical patterns associated with the carriage of ESBL-producing isolates may allow healthcare providers to identify more rapidly at risk patients. This matter is of particular concern because of the growing proportion of ESBL-producing <it>Enterobacteriaceae </it>species isolates worldwide.</p> <p>Methods</p> <p>We undertook a descriptive analysis of 114 consecutive patients in whom ESBL-producing <it>Enterobacteriaceae </it>isolates were collected from clinical specimens over a 20-month period. Clinical data were obtained through retrospective analysis of medical record charts. Microbiological cultures were carried out by standard laboratory methods.</p> <p>Results</p> <p>The proportion of ESBL-producing <it>Enterobacteriaceae </it>strains after exclusion of duplicate isolates was 4.5% and the incidence rate was 4.3 cases/1000 patients admitted. Healthcare-associated acquisition was important (n = 104) while community-acquisition was less frequently found (n = 10). Among the former group, two-thirds of the patients were aged over 65 years and 24% of these were living in nursing homes. Sixty-eight (65%) of the patients with healthcare-associated ESBL, were considered clinically infected. In this group, the number and severity of co-morbidities was high, particularly including diabetes mellitus and chronic renal insufficiency. Other known risk factors for ESBL colonization or infection such as prior antibiotic exposure, urinary catheter or previous hospitalisation were also often found. The four main diagnostic categories were: urinary tract infections, lower respiratory tract infections, septicaemia and intra-abdominal infections. For hospitalized patients, the median hospital length of stay was 23 days and the average mortality rate during hospitalization was 13% (Confidence Interval 95%: 7-19). <it>Escherichia coli</it>, by far, accounted as the most common ESBL-producing <it>Enterobacteriaceae </it>species (77/114; [68%]) while CTX-M-1 group was by far the most prevalent ESBL enzyme (n = 56).</p> <p>Conclusion</p> <p>In this retrospective study, the clinical profiles of patients carrying healthcare-associated ESBL-producing <it>Enterobacteriacae </it>is characterized by a high prevalence rate of several major co-morbidities and potential known risk factors. Both, the length of hospital stay and overall hospital mortality rates were particularly high. A prospective case-control matched study should be designed and performed in order to control for possible inclusion bias.</p

Redox potential as a diagnostic tool to investigate growth of various clinical pathogens

Introduction: Through their oxidative metabolism, bacteria reduce the redox potential of their environment. It is thus possible to detect a bacterial growth by measuring the redox potential of the culture broth. Methods: We have determined the oxydoreduction curves (shape and kinetics) of different pathogens at serial initial concentrations. Material: We have used basic potentiometers associated to combined redox electrodes with an Ag/AgCl reference. Repeated measurements have been performed on a strirred Tryptic Soya broth maintained at 37°C. Results: We have shown that there is a linear correlation between the initial germs concentration and the time needed to observe a diminution of the potential (in mV). Additionally, the shape and kinetics of the curves are reproductible and specific to the microbial species. We have equally studied the effect of different concentrations of antibiotics on the variation of the redox potential. Conclusions: These preliminary studies show that there is a big “potential” for the use of electrochemistry for qualitative and quantitative diagnosis of a bacterial infection and its associated antibiotics resistances. If proven implementable, this technique would offer the consequent advantages of being low-cost and faster than actual diagnosis methods

Evaluation of the Roche® Elecsys and the Diasorin® Liaison S100 kits in the management of mild head injury in the emergency room

Introduction: The aim of this single-center prospective study is to compare two commercially available S100 beta kits (the Roche (R) Elecsys and the Diasorin (R) Liaison S100 kits) in terms of analytical and clinical performances in a population admitted in the emergency room for mild traumatic brain injury (mTBI). Material and method: 110 patients were enrolled from September 2014 to May 2015. Blood sample draws were performed within 3 h after head trauma and the study population was split into pediatric and adult sub-populations (> 18 years of age). Results: Although both kits correlated well, we observed a significant difference in terms of S100 beta levels (P value < 0.05) in both subpopulations. In the pediatric subpopulation, both kits showed elevated S100 beta levels for the only patient (3.5%) who displayed abnormal findings on a CT-scan. However, we observed a poor agreement between both kits (Cohen's kappa = 0.345, P value = 0.077). In the adult subpopulation, a total of 10 patients (12.2%) had abnormal head computed tomography scans. Using the Roche (R) (cut off = 0.1 mu g/L) and the Diasorin (R) (cut off = 0.15 mu g/L) S100 beta kits, brain injuries were detected with a sensitivity of 100% (95% CI: 65-100%) and 100% (95% CI: 63-100%) and a specificity of 15.28% (95% CI: 7.9-25.7%) and 24.64% (95% CI: 15-36.5) respectively. Finally, a moderate agreement was concluded between both kits (Cohen's kappa = 0.569, P value = 0.001). Conclusion: Although a good correlation could be found between both kits, emergency physicians should be aware of discrepancies observed between both methods, making those immunoassays not interchangeable. Furthermore, more studies are still needed to validate cut off used according to technique and to age, especially in the population below the age of 2 years