Central Venous Catheter Colonization Research Articles

Chlorhexidine gluconate solution prevented catheter colonization and infection

Source Citation Mimoz O, Pieroni L, Lawrence C, et al. Prospective, randomized trial of two antiseptic solutions for prevention of central venous or arterial catheter colonization and infection in ...

Bacterial colonization of indwelling vascular catheters in newborn infants.

To determine the incidence of bacterial colonization of intravascular catheters, to compare the incidence of colonization of intra-arterial (IA), intravenous (IV) and central venous catheters (CVC), and to determine the association, if any, between catheter withdrawal and bacterial sepsis. A prospective observational study was carried out at the neonatal intensive care unit of a university-affiliated regional referral centre. A total of 155 catheters (45 IA, 54 IV and 56 CVC) were obtained from 96 infants admitted to the unit and the distal 0.75 cm studied under the scanning electron microscope. The adjoining 0.75 cm was cultured for bacteria. Scanning electron microscopy revealed that 46% of catheters had bacteria on the internal surface and 13% had bacteria on the outer surface. Greater numbers of CVC were colonized with bacteria compared to IA and IV catheters (P < 0.01). Bacterial colonization of intravascular catheters was not significantly associated with the duration the catheter remained in situ or local reaction at the site of entry of the catheter. Colonization of the external surface of the catheter was significantly associated with bacterial septicaemia (P = 0.0466). Eighty-three per cent of 155 catheters studied had coagulum on the inner or outer surface. Only 53% of these were colonized with bacteria. Bacterial colonization occurred in the absence of a coagulum in only three instances. Catheter withdrawal was not associated with bacterial sepsis. Lack of coagulum on the internal surface of the catheter was strongly associated with septicaemia during the 7 days after catheter withdrawal. Although significant numbers of intravascular catheters were colonized with bacteria, only colonization with the external surface was associated with catheter-related sepsis.

Surface heparinization of central venous catheters reduces microbial colonization in vitro and in vivo

To evaluate in vitro and in vivo the efficacy of covalent end point-attached heparin to single-lumen polyurethane central venous catheters in reducing microbial adherence and colonization. In vitro study: A controlled bench study. In vivo study: A prospective, randomized, double-blind, clinical trial. Intensive care unit in a 1200-bed teaching hospital. In vitro study: Adhesion of 17 radiolabeled clinical isolates of Staphylococci to catheters was examined in vitro. In vivo study: The outcome of heparinized and control catheters was compared in vivo in patients receiving long-term parenteral nutrition. Fifty-five adult patients were prospectively, blindly randomized to heparinized or control central venous catheters. The catheters, removed on clinical grounds, were analyzed with semiquantitative and quantitative cultures. Blood cultures were done at catheter removal. In vitro study: Coagulase-negative Staphylococci adhered less in vitro to heparinized catheters than to control catheters (p < .05). In vivo study: Among 32 central venous catheters, or patients who completed the study, catheter-associated bacteremia or fungemia was observed in five patients in the control group (n = 19) and in no patient with a heparinized catheter (n = 13) (p = .047). Four of 13 catheters in the heparin group were colonized compared with 14 of 19 in the control group (p = .03). Coagulase-negative Staphylococci were the most frequent microorganisms in both groups. The numbers of organisms found on colonized catheters were larger in the control group than in the heparin group. Covalent end point surface heparinization appears to have a great impact on both in vitro and in vivo bacterial colonization of central venous catheters. Such heparinization can be a practical and economical approach to the prevention of catheter-associated bacteremia or fungemia.

Retention of antibacterial activity and bacterial colonization of antiseptic-bonded central venous catheters.

We determined how long antiseptic impregnation with silver sulphadiazine and chlorhexidine (SCC) on polyurethane central venous double- or triple-lumen catheters is retained in vivo. A total of 116 antiseptic catheters were tested for antibacterial activity in an in-vitro bioassay after various periods of iv catheterization. Segments from the subcutaneous (sc) and intravenous (iv) portions of the catheters were cultured. The results of test antiseptic catheters were compared with those from 117 noncoated control (c) catheters. Retention of antibacterial activity followed an exponential curve and lasted for up to 520 h after catheter insertion. Significant differences (P = 0.0001) between SSC and C catheters were noticed with regard to the quantitative level of bacterial colonization (SSC-sc 87 +/- 34 vs C-sc 584 +/- 122; SSC-iv 52 +/- 17 vs C-iv 286 +/- 57; all values are given as mean cfu +/- S.E.M.), and the frequency of bacterial colonization (SSC-sc 20.7% vs C-sc 38.5%, P = 0.0047; SSC-iv 18.1% vs C-iv 30.8%, P = 0.0361). There was no significant difference between the incidence of catheter-related bacteraemia in the test (n = 0) and control groups (n = 3) (P = 0.2573). Further prospective studies are required to delineate the role of antiseptic catheters in preventing catheter-related infections.

Mupirocin resistance in coagulase-negative staphylococci, after topical prophylaxis for the reduction of colonization of central venous catheters

Topical mupirocin was routinely applied to insertion sites of central venous catheters (CVC) of neonates in a neonatal intensive care unit. After five years, mupirocin resistance was recorded in 42% of clinical isolates of coagulase-negative staphylococci (CNS). This decreased to 21% during a mupirocin-free interval of five months. We performed a prospective study on the significance of mupirocin use on the staphylococcal skin flora of 15 newly admitted neonates. During treatment, mupirocin-susceptible strains were replaced by highly resistant ones. After treatment, all but one neonate harboured at least one resistant strain; 29% of all strains were moderately resistant (mupirocin minimum inhibitory concentrations (MICs) 16 mg/L) and 55% were highly resistant (MICs > 1024 mg/L). One CVC (7%) became colonized with a resistant strain. One year after stopping routine mupirocin application the incidence of resistance had dropped to 13%; CVC colonization was recorded in 2–4%.

Malassezia furfur-related colonization and infection of central venous catheters

To determine the incidence of Malassezia furfur-related colonization and infection of central venous catheters. Prospective clinical study. A paediatric intensive care unit at a University Hospital. 66 newborns with central venous catheters for parenteral nutrition including lipid emulsions (Intralipid). When a central venous catheter was removed, it was rinsed with 1 ml of physiological saline, transported at ambient temperature to the clinical laboratory and cultured on Dixon's medium. The tip of the central venous catheter was used for a bacteriological study using Maki's technique. In case of suspected sepsis, blood cultures were obtained using an Isolator tube. RESULTS. 74 central venous catheters were included: mean duration of use of a central venous catheters and infusions of lipid emulsion (Intralipid) were 19.3 +/- 10 days and 8.6 +/- 8 days respectively. Only 2 central venous catheters (2.7%) were colonized by Malassezia furfur: (Mf) one in an asymptomatic newborn, and the other in an infected newborn with signs of sepsis, who most probably died at 4 months of age from refractory hypoxia due to pulmonary hypoplasia, but not from Mf sepsis. The incidence of Malassezia furfur-related colonization of central venous catheters appears to be low but not negligible, which warrants the use of specific culture techniques.

Ultrastructural analysis of indwelling vascular catheters: a quantitative relationship between luminal colonization and duration of placement.

To assess the degree of luminal and extraluminal colonization of long-term central venous catheters (CVC), 359 indwelling silicone CVC from 340 consecutive cancer patients were examined. All CVC were cultured by the roll-plate and sonication quantitative culture techniques. Semiquantitative electron microscopy was done on 39 CVC associated with catheter infections and on 26 culture-negative controls. An additional 10 culture-negative CVC obtained after death were also studied by electron microscopy. Ultrastructural colonization and biofilm formation was universal and quantitatively independent of clinical catheter-related infections. Ultrastructural colonization and biofilm formation was predominantly luminal in long-term CVC (> 30 days). Based on a composite definition, the sensitivity of the roll-plate catheter tip culture was 42%-45% compared with 65%-72% for the sonication of the tip. Colonization of indwelling catheters is universal regardless of culture results. For long-term CVC, colonization becomes predominantly luminal and extraluminal quantitative catheter cultures are of limited diagnostic sensitivity.

In vitro Experiments on Catheter-Related Infections Due to Gram-Negative Rods

Although many complications may arise with the use of central venous catheters, catheter-related bacteremia is considered to be the most serious complication. Microflora on the patient's skin (coagulase-negative staphylococci, Staphylococcus aureus) is thought to represent the major source of microorganisms causing catheter-related infections. Gram-negative rods are increasingly observed as causative agents. We therefore performed an in vitro study to elucidate the pathogenesis of polymer-associated infections caused by enterobacteriaceae and nonfermenters and to study the resistance of polymer surface-grown gram-negative rods against antibiotics. Using a modification of the semiquantitative method for culturing vascular cannulas on solid media described by Maki et al., we studied the adherence of various gram-negative rods to 1-cm segments of silastic catheters, a material used for Port-A-Cath-systems. Organisms were obtained from the American Type Culture Collection (Escherichia coli, Klebsiella pneumoniae, Serratia marcescens, Pseudomonas aeruginosa, Enterobacter cloacae). All organisms but Klebsiella showed extensive irreversible adherence. Production of an extracellular slime substance was observed only with antimicrobially treated Pseudomonas. After 'infection', the silastic catheter segments were treated with various antimicrobial agents. The following antibiotics were used either individually or in combination: cefotaxime, ciprofloxacin, imipenem, fosfomycin and gentamicin. Despite the fact that the antibiotic concentrations used were many times greater than the respective MICs of the various antibiotics, none of the antibiotics tested succeeded in eliminating the organisms. E. coli was found to be the most susceptible organism. These in vitro data substantiate our clinical impression that it is hardly possible to successfully eliminate the colonization of central venous catheters with gram-negative rods by using the antimicrobial agents employed here.

In vitro and in vivo effect of antibiotics on catheters colonized by staphylococci.

An in vitro model was used to study whether and how catheter infections can be cured. Silastic catheters were "infected" with Staphylococcus aureus ATCC 25923 and Staphylococcus epidermidis KH11 and V2; these "infections" were then treated with 24, 48 and 96 h continuous infusions of various antimicrobial agents administered both as monotherapy and in combination. The Staphylococcus aureus strain was considerably more difficult to eliminate from catheters than were the Staphylococcus epidermidis strains. This experience gained in the laboratory was then applied in vivo to 16 episodes of catheter sepsis in seven children. Treatment for at least six days with imipenem/cilastatin combined with fosfomycin or an aminoglycoside successfully eliminated the pathogens isolated from 11 of the 16 episodes of infection. The broad-spectrum combination was chosen because it could not be assumed that individual pathogens would be sensitive to a single substance. Nine of the infected catheters could be retained in the patients. This experience suggests that it may be possible to successfully eliminate the colonization of central venous catheters by coagulase-negative staphylococci using the antimicrobial agents employed here.

Bacterial colonization of central venous catheter (CVC) subcutaneous tract in pediatric patients

Bacterial colonization of central venous catheter (CVC) subcutaneous tract in pediatric patients

Percutaneous Central Venous Catheter Colonization With Malassezia furfur: Incidence and Clinical Significance

Malassezia furfur colonization of central venous catheters has been implicated in the pathogenesis of systemic infections with this lipid-dependent yeast. To determine the incidence of catheter colonization in our neonatal intensive care unit (NICU), 25 consecutively removed percutaneous central venous catheters were examined by rinsing the lumen with saline and plating the rinse fluid on Sabouraud dextrose agar overlaid with olive oil. M furfur grew from the lumina of eight catheters (32%). Surveillance skin cultures were performed in the NICU on two occasions to determine the prevalence of skin colonization with M furfur. M furfur was found on the skin of 64% of the infants. In contrast, only 3% (1/33) of healthy, nonhospitalized infants 2 to 8 weeks of age had skin colonized with M furfur. During the 5-month study period, two NICU infants had evidence of systemic infection with M furfur. We conclude that M furfur frequently colonizes both the skin and percutaneous central venous catheters in NICU infants. Further studies are needed to determine the relationship between skin colonization and catheter colonization, and the factors contributing to systemic disease with this organism.