Quantitative Culture of Intravenous Catheters and Other Intravascular Inserts

Abstract

Quantitative cultures were done on 149 intravenous catheters and 40 additional intravascular inserts. Intradermal and intravascular segments of the insert were cultured separately. The inserts were immersed in broth and flushed. The number of colony-forming units (cfu) per insert was estimated by surface culture of serial dilution of the broth. Nonquantitative culture of undiluted broth was also done. Since all inserts associated with bacteremia had at least 10(3) cfu, inserts greater than 10(3) cfu were considered infected. Staphylococcus epidermidis was more likely than more virulent organisms to colonize an insert without causing bacteremia. The inserts in one bacteremic patient were infected from a distant bloodstream focus; however, in the majority of patients, quantitative intradermal cultures suggested that the insertion site was the portal of entry. In bacteremic patients, either a positive quantitative or a nonquantitative culture identified an infected insert. However, only 33% of positive nonquantitative insert cultures from nonbacteremic patients were confirmed by quantitative insert culture.

Candidaemia in a tertiary care academic hospital in Italy. The impact of C. parapsilosis complex on the species distribution and antifungal susceptibility

“…Positive samples were then inoculated on Sabouraud dextrose agar supplemented with chloramphenicol (Oxoid spa, Milan, Italy) and cultured for at least 24 h at 37 C. IVDs were microbiologically examined within 15 min after the removal of the device according to the quantitative culture method of Cleri et al [13], with slight modifications. In brief, approximately 5 cm of the distal part of the device was placed in 1 ml of BHI broth (Biolife Italiana s.r.l., Milan, Italy) and vigorously shaken on a vortex for 30 s. A total of 10 µl of the suspension was then streaked on agar plates.…”

Stpahylococcus aureus biofilms on central venous haemodialysis catheters

“…Catheter cultures were performed by a modified quantitative method described by Cleri et al (7), and carried out by flushing the catheter lumen with 4mL of Trypticase Soy Broth (TSB; BBL Microbiology Systems, Cockeysville, Md. ), which was then diluted 10-fold, and each dilution (0.1mL) was streaked onto 5% sheep-blood agar plates.…”

Closed Blood Conservation Device for Reducing Catheter-Related Infections in Children After Cardiac Surgery

“…In addition, with the semiquantitative method described by Maki et al, 24 only the external surface of a catheter tip is sampled, and the VAMP device might prevent internal colonization better than it prevents external colonization because the device forms a closed system. The quantitative catheter segment culture technique reported by Cleri et al 32 might be a more suitable method for investigating the effect of a VAMP device on colonization of catheter tips.…”