[Staphylococcus aureus nosocomial infections in critically ill patients admitted in intensive care units]

Antimicrobial properties of a novel copper-based composite coating with potential for use in healthcare facilities

Background

Healthcare-associated infections (HAIs) have a major impact on public health worldwide. Particularly, hospital surfaces contaminated with bacterial pathogens are often the origin of both sporadic cases and outbreaks of HAIs. It has been demonstrated that copper surfaces reduce the microbial burden of high touch surfaces in the hospital environment. Here we report the antimicrobial characterization of a novel composite coating with embedded copper particles, named Copper Armour™.

Methods

The Copper Armour™ bactericidal activity was evaluated in in vitro assays against several bacterial pathogens, including Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli O157:H7 and Listeria monocytogenes. Additionally, its antimicrobial properties were also evaluated in a pilot study over a nine-week period at an adult intensive care unit. For this, four high touch surfaces, including bed rails, overbed table, bedside table and IV Pole, were coated with Cooper Armour™, and its microbial burden was determined over a nine-week period.

Results

Copper Armour™ coated samples showed an in vitro reduction in bacterial burden of > 99.9% compared to control samples. Moreover, pilot study results indicate that Copper Armour™ significantly reduces the level of microbial contamination on high-touch surfaces in the hospital environment, as compared with standard surfaces.

Conclusions

Based on its antimicrobial properties, Copper Armour™ is a novel self-sanitizing coating that exhibits bactericidal activity against important human pathogens and significantly reduces the microbial burden of hospital surfaces. This composite could be used as a self-sanitizing coating to complement infection control strategies in healthcare facilities.

Evaluation of antimicrobial efficacy of flavonoids of withania somnifera L

In the present study antimicrobial activity of Withania somnifera L. Dunal (Solanaceae) has been evaluated against selected pathogens. Free and bound flavonoids of different parts (root, stem, leaf and fruit) of W. somnifera have been studied for their antimicrobial activity using disc diffusion assay against three Gram negative bacteria (Escherichia coli MTCC 46, Proteus mirabilis MTCC 3310 and Pseudomonas aeruginosa MTCC 1934), one Gram positive bacteria (Staphylococcus aureus MTCC 3160) and three fungi (Candida albicans MTCC 183, Aspergillus flavus MTCC 277 and Aspergillus niger MTCC 282). Minimum inhibitory concentration (MIC) of the extracts was evaluated through micro broth dilution method, while minimum bactericidal/fungicidal concentration was determined by sub culturing the relevant samples. C. albicans was found to be the most susceptible organism followed by S. aureus, P. mirabilis, E. coli and P. aeruginosa. Out of the tested organisms, A flavus and A. niger were observed to be resistant as none of the tested extracts showed activity against them. Total activity (TA) of extracts (ml/g) against each sensitive pathogens was also evaluated. Bound flavonoid extract of root showed best activity against C. albicans (IZ 30, MIC 0.039, MFC 0.039, respectively). However all the microorganisms were found to be sensitive against the extracts tested. Total activity of bound flavonoid extract of root was found to be same for E.coli, P. mirabilis, S. aureus and C. albicans (153.84 ml/g). Results of the present study reveal that extracts of W. somnifera showing great antimicrobial potential against test microorganisms may be exploited for future antimicrobial drugs.

Impact of administration of vancomycin or linezolid to critically ill patients with impaired renal function

The aim of this study was to assess the impact of vancomycin (VAN) versus linezolid (LZD) on renal function in patients with renal failure (RF) admitted to intensive care units. This was a multicenter, retrospective, comparative cohort study. Renal failure patients were treated with VAN or LZD for proven or suspected infections by multiresistant Gram-positive cocci. Changes in plasma creatinine levels and creatinine clearance at the start and end of treatment were used as endpoints. A total of 147 patients were treated with VAN (group A, n = 68) or LZD (group B, n = 79). Group B included more patients with diabetes mellitus [9 (13.2%) vs. 25 (31.6%); p = 0.007], septic shock [39 (57.4%) vs. 60 (75.9%); p = 0.013] and greater RF (mean ClCr 42.24 ml/min vs. 37.57 ml/min; p = 0.04). Renal function improved in patients from both groups who did not require renal replacement therapy. A greater improvement was seen in group B [percent decrease in Cr (27.94 vs. 9.48; p = 0.02) and percent increase in ClCr (95.96 vs. 55.06; p = 0.05)]. In group A, nine patients (13.2%) experienced an antibiotic-related increase in RF, and antibiotic was discontinued in five patients due to adverse effects. It is reasonable to avoid use of VAN in critically ill patients with acute renal failure.

[Oral hygiene with chlorhexidine on the prevention of ventilator-associated pneumonia in intubated patients: a systematic review of randomized clinical trials]

BACKGROUND AND OBJECTIVE

Mechanical ventilation is used in about one third of patients in intensive cares units (ICU). Ventilator Associated-Pneumonia (VAP) is a frequent infectious complication, affecting approximately 8 to 28% patients. Strategies to prevent the development of VAP are key factors in the management of ICU patients. There have been proposed several strategies to prevent VAP. One of these is oral hygiene with clorhexidine. We evaluated the effect of chlorhexidine on the prevention of VAP.

PATIENTS AND METHODS

We conducted a systematic review of controlled clinical trials evaluating the effect of oral hygiene on VAP prevention. A PubMed search was performed using the following keywords: "oral care OR oral hygiene OR chlorhexidine AND ventilator-associated pneumonia". An independent reviewer evaluated the studies according to the inclusion criteria and extracted the data.

RESULTS

A total of 120 articles were found, and 10 of them met the inclusion criteria. A lack of uniformity was appreciated in the application of chlorhexidine. There was a reduction in the risk of VAP in the chlorhexidine group versus control (OR: 0,56, 95% CI: 0,44-0,73). However, neither a reduction in mortality, nor a length of MV nor an ICU length of stay were seen.

CONCLUSIONS

Oral hygiene with chlorhexidine in combination with other strategies for VAP prevention should be included in the patient's ICU care.

[Staphylococcus aureus infection in an acute geriatric unit]

OBJECTIVE

The aim of this study was to determine the risk of mortality, functional decline and institutionalization, as well as the hospital cost associated with patients with methicillin-resistant Staphylococcus aureus (MRSA) infection in an Acute Geriatric Unit (AGU).

MATERIAL AND METHODS

We retrospectively gathered data on patients admitted to the AGU over a 5-year period (from 1/1/2001 to 1/1/06). Mortality, institutionalization, functional impairment at discharge, length of hospital stay, and hospital costs were compared between patients with and without MRSA. MRSA infection was documented by the microbiology department using culture and antibiogram, as well as by clinical diagnosis of hospital infection registered in the medical record.

RESULTS

Data were obtained from 47 patients with MRSA (mean age 86.15+/-5.5 years) and from 4281 patients without MRSA (mean age 85.25+/-6 years). MRSA-infected patients had higher mortality (25.5% vs. 7.7%, p<0.001), worse functional status at discharge (Barthel index 39.43+/-33.05 vs. 55.24+/-34.99, p<0.01) and more frequent institutionalization (29% vs. 9%, p<0.001). Longer length of hospital stay (22.15+/-13.67 vs. 10.64+/-7.69 days, p<0.001) and higher hospital cost per patient (7517.71+/-4639.59 vs 3611.21+/-2609.98 euro, p<0.001) were also observed. In the multivariate analysis adjusted by age, sex, and baseline functional and cognitive status, MRSA infection was independently associated with higher mortality (OR=3.92; 95% CI=1.95-7.86), worse functional status at discharge (OR=2.48; 95% CI=1.22-5.01), institutionalization at discharge (OR=6.50; 95% CI=2.60-12.22), and substantial increase in length of hospital stay (Beta coefficient=11.55 days; 95% CI=9.32-13.75).

CONCLUSION

MRSA infection in the AGU is associated with higher mortality, worse functional status at discharge and a higher incidence of institutionalization, as well as significantly longer length of stay and higher hospital costs.

[Nosocomial infection indicators]

Nosocomial infection indicators are a reflection of healthcare quality and patient safety in hospitals. Infection indicators are calculated using surveillance programs and/or systems. Current nosocomial infection surveillance systems are based on both prevalence and incidence studies. Since 1990 the EPINE prevalence study, promoted by the Spanish Society for Preventive Medicine, Public Health and Hygiene, has developed 25 nosocomial infection indicators in hospital patients in Spain. And since 1994 the ENVIN-HELICS incidence study, promoted by the Infectious Diseases Working Group of the Spanish Society for Intensive and Critical Care Medicine and Coronary Units, has developed nine ICU-acquired infection indicators in critical patients. Participation in both surveillance systems is voluntary and has gradually increased over the years. These two control systems present the results of two different situations in the area of nosocomial infection and each complements the other; in addition, they have helped to train health professionals and to raise their awareness of nosocomial infection and patient safety. This article presents the indicators obtained in 2007 through both surveillance programs as well as their standards of reference.

[Use of antibiotics for the treatment of multiresistant gram positive cocci infections in critical patients]

INTRODUCTION

This study has been designed to know the use of these antibiotics (ATB) in Intensive Care Units (ICUs).

DESIGN AND PATIENTS

A multicentric, prospective, observational study was conducted. In cluded as cases were the indications of vancomycin (VAN), teicoplanin (TPN), quinupristin/dalfopristin (Q/D) and linezolid (LZD).

RESULTS

A total of 826 indications (VAN 52.1%, TPN 36.6%, LZD 11.6% and Q/D 0%) were analyzed, 793 (96%) as treatment and 33 (4%) as prophylaxis in 818 patients. Serious sepsis or septic should occurred in 55.9% of the patients treated. The most common infections were pneumonia and catheter-related bacteremia, 48.3% of all the infections being acquired in ICUs. LZD was used mostly in mechanical-ventilation related pneumonia (p = 0.001), VAN in community Central Nervous System infections (p = 0.01) and in catheter-related bacteremia (p = 0.001), TPN in community pneumonia (p = 0.01) and in catheter-related bacteremia (p = 0.001). Treatments were empirical in 65.8% and diagnosis of gram positive cocci was confirmed in 48.3% of them. Staphylococcus aureus was isolated more in the LZD-treated group. Initial treatment was modified 224 times, this occurring more frequently in the VAN-treated group. The reason for this change was clinical failure 59 times, this being more frequent in the TPN group and less frequent in the patients treated with LZD, which was the drug used the most in rescue therapies (43/69, 62.3%). Adverse events, probably related to the ATB, were identified in 36/826 (4.4%) cases.

CONCLUSIONS

The most common use of this ATB was to treat ICU-acquired infections. VAN was the most frequently used drug. Treatments with LZD were modified less frequently for clinical failure and this drug was the one most used in rescue therapies. This information indicates an appropriate use of these ATB in an important percentage of critically patients.

Modelo predictivo de neumonía nosocomial en unidades de cuidados intensivos

BACKGROUND AND OBJECTIVE

Nosocomial pneumonia is the most common nosocomial infection in the intensive care units (ICUs) and contributes disproportionately to both poor outcomes and high cost of care in critically ill patients. In order to identify patients with greater risk of developing nosocomial pneumonia in ICUs, it is important to select the right preventive measures.

PATIENTS AND METHOD

It was an observational study of 2 prospective cohorts of patients staying in the ICU for 24 h or more: the main cohort (n=1,184) and the validation cohort (n=554). A predictive model was constructed with the data of the main cohort using a logistic regression. Receiver operating characteristic (ROC) curves and predictive values for different cut points were obtained with the data of both cohorts.

RESULTS

Eight variables were selected for the predictive model: parenteral nutrition, enteral nutrition, nasogastric intubation, tracheostomy, mechanical ventilation, previous surgery, coma and diabetes. In the main cohort, the model had a sensitivity of 81% and a specificity of 78.4% in predicting nosocomial pneumonia (Hosmer-Lemeshow statistic p=0.93; area under ROC curve=0.861; 95% confidence interval, 0.824-0.898). In the validation cohort, the area under ROC curve was 0.849 (95% confidence interval, 0.742-0.956).

CONCLUSIONS

The resulting model presents satisfactory results in both cohorts. In addition, the variables used are simple, routinely available, and familiar to clinicians.

Gram-positive cocci infections in intensive care: guide to antibacterial selection

The incidence of multiresistance in Gram-positive cocci causing infections in critically ill patients admitted to the intensive care unit (ICU) has increased notably in recent years. Thus, therapeutic proposals have been modified according to the emergence of multiresistant cocci and adapted to epidemiological markers of individual infectious processes, geographical variations of these markers, the availability of new antibacterials, and advances in the knowledge of pharmacokinetic and pharmacodynamic aspects of their use. The current management of critically ill patients should consider new therapeutic approaches, such as the "de-escalating strategy", which includes the administration of empirical antibacterials active against multiresistant pathogens followed by directed treatment based on unequivocal data from antibacterial-susceptibility testing. Optimisation of antibacterial treatment should be viewed in the context of the need to determine plasma drug concentrations, pharmacoeconomic considerations and control of drug-related adverse events. Therapeutic proposals should be developed within the framework of the antibacterial policy of each hospital. The present review is focused on the description of the therapeutic strategies for the main infectious processes caused by Gram-positive cocci in severely ill patients admitted to the ICU according to a review of the pertinent literature and the clinical experience of the authors.