Nosocomial gram-negative bacteremia

New Biofunctional Loading of Natural Antimicrobial Agent in Biodegradable Polymeric Films for Biomedical Applications

The study focuses on the development of novel Aloe vera based polymeric composite films and antimicrobial suture coatings. Polyvinyl alcohol (PVA), a synthetic biocompatible and biodegradable polymer, was combined with Aloe vera, a natural herb used for soothing burning effects and cosmetic purposes. The properties of these two materials were combined together to get additional benefits such as wound healing and prevention of surgical site infections. PVA and Aloe vera were mixed in a fixed quantity to produce polymer based films. The films were screened for antibacterial and antifungal activity against bacterial (E. coli, P. aeruginosa) and fungal strains (Aspergillus flavus and Aspergillus tubingensis) screened. Aloe vera based PVA films showed antimicrobial activity against all the strains; the lowest Aloe vera concentration (5%) showed the highest activity against all the strains. In vitro degradation and release profile of these films was also evaluated. The coating for sutures was prepared, in vitro antibacterial tests of these coated sutures were carried out, and later on in vivo studies of these coated sutures were also performed. The results showed that sutures coated with Aloe vera/PVA coating solution have antibacterial effects and thus have the potential to be used in the prevention of surgical site infections and Aloe vera/PVA based films have the potential to be used for wound healing purposes.

Bacteremia due to Pseudomonas aeruginosa: results from a 3-year national study in the Slovak Republic

Risk factors, mortality and antimicrobial susceptibility of Pseudomonas aeruginosa bacteremias isolated from 148 patients from all University Hospitals in Slovakia were analyzed. Only 1.2% of 169 strains of P. aeruginosa were resistant to meropenem, 4.1% to piperacillin/tazobactam, 7.7% to ceftazidime as well as cefepime and 12% to amikacin. More than 30% of P. aeruginosa were resistant to ciprofloxacin. Our analysis of risk factors for antimicrobial resistance to the particular antimicrobials, indicated no difference in risk factors and outcome in cases infected with P. aeruginosa bacteremias resistant to amikacin, piperacillin/tazobactam or ceftazidime in comparison to episodes caused by P. aeruginosa due to susceptible isolates. When comparing risk factors for P. aeruginosa bacteremia in children vs. adults, cancer vs. non-cancer patients, several differences in risk factors were observed. Neither antimicrobial resistance to amikacin, ceftazidime or piperacillin/tazobactam, nor appropriateness of therapy according to two separate analyses were associated with better outcome.

Bloodstream infection surveillance in a cancer centre: a prospective look at clinical microbiology aspects

A prospective clinical and microbiological surveillance study was conducted during a 26-month period to evaluate consecutive malignancy or post-bone marrow transplant patients with positive blood cultures. The study included 859 episodes of bloodstream infection (BSI) in 719 patients. There were 6.9 BSI episodes/1000 patient-days. Overall mortality was 25%. The median age of patients was 43 years, with 71% of episodes occurring in patients aged > 18 years. Patients with underlying haematology malignancies accounted for 38.2% of the episodes. An indwelling central vein catheter was present in 61% of episodes. BSI origin was unknown in 27% of episodes, associated with other sites in 49.6%, and catheter-related in 23.4%. There were 638 concomitant infection sites, of which the most common were pulmonary (28.4%), urinary tract (14.8%), and non-surgical skin or soft tissue (9.7%). In total, 1039 microorganisms were isolated within 48 h of the first blood culture, of which Gram-negative bacilli accounted for 56%. Among Klebsiella pneumoniae and Escherichia coli isolates, 37.8% and 8.9%, respectively, produced extended-spectrum beta-lactamases. High rates of ceftazidime resistance were detected among Acinetobacter spp. (40%) and Enterobacter spp. (51.2%). E. coli and K. pneumoniae were isolated frequently from haematology patients, and Enterobacter spp. from solid tumour patients. E. coli, K. pneumoniae and Pseudomonas aeruginosa were isolated more often from neutropenic than from non-neutropenic patients. Oxacillin resistance was detected in 18.7% of Staphylococcus aureus isolates. It was concluded that continuous multidisciplinary surveillance of BSI is warranted in this high-risk group of patients in order to develop strategies for antimicrobial resistance control and treatment of infectious complications.