Successful daptomycin lock therapy for implantable intra-arterial catheter infection in a patient with liver metastases of colon cancer

Multifunctional Pharmaceutical Effects of the Antibiotic Daptomycin

Daptomycin (DAP), a cyclic lipopeptide produced by Streptomyces roseosporus, is a novel antibiotic to clinically treat various Gram-positive pathogenic bacteria-induced infections. Although DAP has a strong broad-spectrum bactericidal effect, recently rare bacterial antibiotic resistance against DAP gradually arises. The review is to summarize the normal indications of DAP, its off-label usage against several clinical pathogen infections, the unique antibacterial mechanisms of DAP, and the combination of antibiotic therapies for highly DAP-resistant pathogens. More noticeably, rising evidences demonstrate that DAP has new potential activity of anticancer and immunomodulatory effects. So far the multifunctional pharmaceutical effects of DAP deserve to be further explored for future clinical applications.

Antibiofilm Activity of Electrical Current in a Catheter Model

Catheter-associated infections are difficult to treat with available antimicrobial agents because of their biofilm etiology. We examined the effect of low-amperage direct electrical current (DC) exposure on established bacterial and fungal biofilms in a novel experimental in vitro catheter model. Staphylococcus epidermidis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida parapsilosis biofilms were grown on the inside surfaces of polyvinyl chloride (PVC) catheters, after which 0, 100, 200, or 500 μA of DC was delivered via intraluminally placed platinum electrodes. Catheter biofilms and intraluminal fluid were quantitatively cultured after 24 h and 4 days of DC exposure. Time- and dose-dependent biofilm killing was observed with all amperages and durations of DC administration. Twenty-four hours of 500 μA of DC sterilized the intraluminal fluid for all bacterial species studied; no viable bacteria were detected after treatment of S. epidermidis and S. aureus biofilms with 500 μA of DC for 4 days.

Strategies for combating bacterial biofilm infections

Formation of biofilm is a survival strategy for bacteria and fungi to adapt to their living environment, especially in the hostile environment. Under the protection of biofilm, microbial cells in biofilm become tolerant and resistant to antibiotics and the immune responses, which increases the difficulties for the clinical treatment of biofilm infections. Clinical and laboratory investigations demonstrated a perspicuous correlation between biofilm infection and medical foreign bodies or indwelling devices. Clinical observations and experimental studies indicated clearly that antibiotic treatment alone is in most cases insufficient to eradicate biofilm infections. Therefore, to effectively treat biofilm infections with currently available antibiotics and evaluate the outcomes become important and urgent for clinicians. The review summarizes the latest progress in treatment of clinical biofilm infections and scientific investigations, discusses the diagnosis and treatment of different biofilm infections and introduces the promising laboratory progress, which may contribute to prevention or cure of biofilm infections. We conclude that, an efficient treatment of biofilm infections needs a well-established multidisciplinary collaboration, which includes removal of the infected foreign bodies, selection of biofilm-active, sensitive and well-penetrating antibiotics, systemic or topical antibiotic administration in high dosage and combinations, and administration of anti-quorum sensing or biofilm dispersal agents.