A fall in bloodstream infections followed a change to 2% chlorhexidine in 70% isopropanol for catheter connection antisepsis: a pediatric single center before/after study on a hemopoietic stem cell transplant ward.

BACKGROUND: Some catheter-related bloodstream infections originate from catheter connectors; therefore, improved antisepsis of these might be expected to reduce the incidence of such infections. METHODS: In this observational before/after study at a pediatric tertiary referral hospital, inpatients up to 16 years old undergoing hemopoietic stem cell transplants were studied. Catheter connection antisepsis was changed from 70% isopropanol alone to 2% chlorhexidine in 70% isopropanol. Numbers of catheter-related bloodstream infections before and after the change were monitored as were the numbers of catheter days experienced by patients. RESULTS: The infection rate before the change was 12 per 1000 catheter-days, and, following the change, this fell to 3 per 1000 catheter-days (P=.004). Similar falls followed the introduction of chlorhexidine to other wards. CONCLUSION: The introduction of chlorhexidine was followed by a profound, sustained fall in catheter-related infections. The results support the 2007 United Kingdom guidelines recommending 2% chlorhexidine in 70% isopropanol as a disinfectant of needleless connectors and hubs of central venous catheters.

Alginate lyase enhances antibiotic killing of mucoid Pseudomonas aeruginosa in biofilms.

Once mucoid (alginate-producing) strains of Pseudomonas aeruginosa have become established in the respiratory tracts of cystic fibrosis patients they can rarely be eliminated by antibiotic treatment alone; we have investigated, in an in vitro biofilm system, the putative role of co-administration of alginate lyase with antibiotic. Biofilms were maintained in continuous flow culture in a medium resembling sputum from CF patients. Antibiotics and/or alginate lyase were added to some of the cultures. Biofilms of two mucoid CF strains of P. aeruginosa were, in most cases, not eradicated by a one-week course of treatment with 64 microg/ml of gentamicin; the same concentration of gentamicin, under the same conditions, led to the apparent elimination of all biofilms of non-mucoid derivatives of these strains. When alginate lyase and gentamicin were administered together the apparent elimination of mucoid bacteria from biofilms was achieved, whereas the mucoid bacteria in most control biofilms treated only with gentamicin persisted. Ceftazidime treatment of biofilms was more effective against those containing the non-mucoid strains than those with mucoid strains. These studies support the view that co-administration of antibiotics with alginate lyase, which degrades the exopolysaccharide produced by mucoid strains of P aeruginosa, might benefit CF patients by increasing the efficacy of antibiotic in the respiratory tract.

Experimental bacteriophage protection against Staphylococcus aureus abscesses in a rabbit model.

In a rabbit model of wound infection caused by Staphylococcus aureus, 2 x 10(9) PFU of staphylococcal phage prevented abscess formation in rabbits when it was injected simultaneously with S. aureus (8 x 10(7) CFU) into the same subcutaneous site. Phage multiplied in the tissues. Phages might be a valuable prophylaxis against staphylococcal infection.