Study on daptomycin use and implementation of an antimicrobial stewardship program

Daptomycin use in adult inpatients in a Canadian tertiary care setting

BACKGROUND

Daptomycin is approved by Health Canada for the treatment of Staphylococcus aureus bacteremia and complicated skin and soft tissue infections caused by gram-positive organisms, but is often used for other indications. We aimed to understand the indications, dosing, and safety profile of daptomycin use in a Canadian inpatient setting.

METHODS

We included consecutive adult patients who received intravenous daptomycin as inpatients from January 1, 2016, to December 31, 2016, at two tertiary care teaching hospitals in Hamilton, Ontario.

RESULTS

We identified 86 courses in 77 unique patients. S. aureus was the most common pathogen (n = 38, 44%) of which 87% (n = 33) were methicillin-resistant. The most common indications were bloodstream infections (n = 31, 36%). The average treatment duration was 10 days, at an average dose of 7.4 mg/kg. The infectious diseases service was consulted in all but two courses. Less than half of treatment courses were given for an indication approved by Health Canada (n = 41, 48%). Almost half of the unapproved indications (n = 21, 47%) followed Infectious Diseases Society of America (IDSA) recommendations. Creatine kinase elevation of 3 × the upper limit of normal or higher occurred in a small number of courses (n = 7, 8%), with only one instance requiring discontinuation of the drug.

CONCLUSIONS

Daptomycin is being used to treat inpatients for a variety of unapproved indications. Importantly, a sizable portion of these are within IDSA guideline recommendations. Most patients are treated with doses higher than the approved 6 mg/kg without major safety concerns.

A promising antibiotic, synergistic and antibiofilm effects of Vernonia condensata Baker (Asteraceae) on Staphylococcus aureus

Vernonia condensata Baker is traditionally used to treat several inflammatory and infectious processes. So, this study evaluated the antibiotic, synergistic and antibiofilm effects, and the mode of action of ethyl acetate fraction from V. condensata leaves (Vc-EAF) against Staphylococcus aureus. Five S. aureus ATCC^® and five methicillin-resistant S. aureus (MRSA) routine strains were used to determine Minimal Inhibitory Concentration (MIC) and Minimal Bactericidal Concentration. The combinatory effect was evaluated by checkerboard and time kill methods; the mode of action through the bacterial cell viability and leakage of compounds absorbing at 280 nm; and the antibiofilm action by quantifying the percentage of adhesion inhibition. Vc-EAF was active against S. aureus (ATCC^® 6538^™), (ATCC^® 25923^™), (ATCC^® 29213^™), (ATCC^® 33591^™), (ATCC^® 33592^™), MRSA 1485279, 1605677, 1664534, 1688441 and 1830466, with MIC of 625 μg/mL for ATCC^®, and 1250, 1250, >2500, 2500 and 2500 μg/mL for MRSA, in this order, with bacteriostatic effect for both ATCC^® and MRSA strains. Vc-EAF plus ampicillin revealed a total synergic effect on MRSA 1485279, and Vc-EAF combined with chloramphenicol, a partial synergic action against S. aureus (ATCC^® 29213^™) and (ATCC^® 25923^™). The time kill data agreed with checkerboard results, and the treated cells number was reduced with release of bacterial content. An expressive bacterial adhesion inhibition for S. aureus (ATCC^® 25923^™) and MRSA 1485279 was detected. These results showed that V. condensata is a promising natural source of active substances against S. aureus, including multiresistant strains, interfering with their antibacterial growth and hampering their adhesion to surfaces.