Novel Strategies to Prevent Catheter-Associated Infections in Oncology Patients

Abstract

Aggressive cytotoxic treatment of cancer contributes to the growing number of life-threatening infections. Vascular catheters create predominant risks for staphylococcal, enterococcal and candida blood stream infections. Although the contaminating microorganisms may be few in number, the altered host immune response in the presence of such implants as well as disease-associated immunosuppression implies that even small bacterial counts have to be regarded as highly virulent species. Diagnosis of catheter-related infection (CRI) remains difficult before withdrawal of the suspected catheter. Positive culture of catheter surface, lumen and hub and positive peripheral blood probes (paired quantitative blood culture) are predictive for catheter related bacteremia (CRB). Diligent catheter care and effective antimicrobial catheters may reduce prolonged hospital stay, increased morbidity or mortality and serious economical consequences. The most promising approach features the incorporation of antimicrobial drugs into the polymer matrices that entrap but do not bind the drugs, allowing for extended release. For the efficacious prevention of colonization in the microenvironment of the implantable device the concentration of the antimicrobial substances must exceed usual antibiotic concentrations by a thousand-fold. This is the desired effect--high concentration near the device surface and very low systemic concentration. Incorporation of antimicrobials in the bulk material that constitutes a device can be effective as shown in several in vitro and in vivo studies. In the future, modification of both short-term and long-term catheters by biofilm-active antimicrobials creating slow delivery systems may provide an effective method to protect patients from nosocomial infection in oncology.

Adjustment of the antibacterial activity and biocompatibility of hydroxypropyltrimethyl ammonium chloride chitosan by varying the degree of substitution of quaternary ammonium

“…Implant-associated periprosthetic infections often lead to implant removal and revision surgery, imposing a huge economic burden on society (Kurtz et al, 2005(Kurtz et al, , 2008Zimmerli, Trampuz, & Ochsner, 2004). Experimental models have proven that the critical dose of contaminating bacteria required to produce infection is much lower when the implant material is present at the surgical site (Cordero, Munuera, & Folgueira, 1996;Elek, 1956;Schierholz, Beuth, Rump, Konig, & Pulverer, 2001;Southwood, Rice, McDonald, Hakendorf, & Rozenbilds, 1985). Bacterial adhesion and anchorage on implant device surfaces represent a crucial initial step in this process (Campoccia, Montanaro, & Arciola, 2006).…”

In vitro effects of micafungin against Candida biofilms on polystyrene and central venous catheter sections

“…Candida is able to attach to polymeric surfaces and generate a biofilm structure, protecting the yeast from host defences and antifungal drugs [2,3]. Production of yeast biofilms is influenced by factors such as prostaglandins, growth rates, pH, dimorphism and liquid flow [4][5][6][7].…”

Nanoseparated Polymeric Networks with Multiple Antimicrobial Properties

“…[15] PEI (MW 5000 g/mol, degree of branching 60 %, i.e., it contains approximately 29 NH 2 R, 58 NHR 2 , and 29 NR 3 groups) was reacted with methacryloyl chloride to introduce polymerizable double bonds. According to 1 H NMR studies, the signal of the CH 2 groups at primary amino groups at 1.59 ppm completely disappeared and a signal corresponding to a methyl group at 1.86 ppm, typical for methacrylate (MA) amides, appeared. Taking into account the sensitivity of NMR spectroscopy, more than 95 % of the primary amino groups of PEI were modified, i.e., the PEI-MA derivative is a multivalent crosslinker with approximately 28 double bonds per molecule and about 87 potential silver binding nitrogen groups.…”

“…antimicrobial: antiadhesive, biocide-release, and contact-active antimicrobial modifications. Most commonly, bulk materials [1] or coatings [2] are loaded with biocides, such as silver ions, [3] halogens, [4] and antibiotics, [5] which are then slowly released into the environment, killing microbes there. Eventually all of these systems are exhausted of active material.…”