Comparison of telavancin and vancomycin lock solutions in eradication of biofilm-producing staphylococci and enterococci from central venous catheters

Staphylococcal and enterococcal infections are very prominent in hospital settings, especially prevalent in patients with inserted devices such as catheters. The bacteria that cause these infections are hard to get rid of and can lead to more serious infections.

In this study, a central venous catheter model was utilized to evaluate lock solutions and their efficacy against bacterial in-line growth. The experiment was done in vitro. Lock solutions containing vancomycin (5 mg/mL) or telavancin (5 mg/mL), with and without preservative containing heparin sodium (2,500 units/mL), heparin, and normal saline solution. The solutions were put into the catheters after the bacteria was given a 24-hour growth period. After 72 hours of exposure to the lock solutions, the catheters were flushed, segmented, and analyzed for bacterial colony growth. In order to establish a baseline, catheters were processed after 24 hours of incubation with any lock solution.

The examined catheter and lock solutions revealed that vancomycin and telavancin (with or without heparin) had similar activity against S. epidermidis and that vancomycin alone was more effective that telavancin against E. faecalis.  Against S. aureus, vancomycin plus heparin had activity similar to that of vancomycin alone; both lock agents had greater activity than telavancin. However, addition of heparin to vancomycin decreased efficacy against E. faecalis and S. epidermidis.

 

Am J Health-Syst Pharm. 2016;73(5):315-21.

 

 

Host gene expression classifiers diagnose acute respiratory illness etiology

Antibiotic resistance is becoming an increasingly hot topic in the news.  The drugs we have been using in the last few decades are starting to face some serious problems with the development of various antibiotic-resistant super bugs.  A great deal of research has been conducted lately regarding ways we can curb this trend to ensure the medications we have will be able to work long into the future.

One cause of growing antibiotic resistant is the mis-diagnosis and subsequent mis-treatment of common respiratory infections.  Often when a patient visits the doctor with this kind of illness, the doctor will prescribe antibiotics without determining if the infection is actually bacterial based or viral based.  A recent article looked at a possible test that could distinguish between the two types of infections, therefore leading to more accurate treatment and curbing inappropriate use of antibiotics.

The researchers analyzed host RNA looking for identifiers that would indicate whether the host, or patient, was responding to a bacterial or viral infection.  It analyzed data on what genes are expressed or over-expressed during each kind of infection to set classifications by which they would be able to analyze the subject’s genetics.

Using these new classifications the prediction of infection type overall in subjects was 87% accurate.

I feel like this could be an extremely impactful test if it becomes implemented in the community setting.  I know so many friends who simply expect antibiotics from their physician when they have a cough.  This puts pressure on the physician to prescribe even if they are not sure of the diagnosis.  With this test it would aid physicians in making a firm diagnosis that they could explain to the patients, curbing inappropriate antibiotic use for viral respiratory infections.

Overall, it seems like this would be a worthwhile test to implement. What problems could arise with the implementation of such a test in a physician’s office?

Tsalik EL, Henao R, Nichols M, et al. Host gene expression classifiers diagnose acute respiratory illness etiology. Sci Transl Med. 2016;8:1-11.

http://stm.sciencemag.org/content/8/322/322ra11