Determination of microbial contamination on the outer surface of needleless connectors before and after disinfection

Abstract

Objectives: The aim of this study was to determine bacterial contamination of needleless connectors before and after disinfection to assess the risk for the point of catheter-related bloodstream infections.

Research methodology/design: Experimental study design.

Setting: The research was carried out on patients with a central venous catheter hospitalized in the intensive care unit.

Main outcomes measures: Bacterial contamination of needleless connectors integrated into central venous catheters was assessed before and after disinfection. Antimicrobial susceptibilities of colonized isolates were investigated. In addition, the compatibility of the isolates with the bacteriological cultures of the patients was determined over a one-month period.

Results: Bacterial contamination varied between 5×10³ and 1×10⁵ colony forming unit was detected before disinfection in 91.7% of needleless connectors. Most common bacteria were coagulase-negative staphylococci; others were Staphylococcus aureus, Enterococcus faecalis, and Corynebacterium species. While most isolates were resistant to penicillin, trimethoprim-sulfamethoxazole, cefoxitin, and linezolid, each was susceptible to vancomycin or teicoplanin. Bacterial survival was not detected on needleless connectors after disinfection. There was no compatibility between the one-month bacteriological culture results of the patients and the bacteria isolated from the needleless connectors.

Conclusion: Bacterial contamination was detected on the needleless connectors before disinfection, although they were not rich in bacterial diversity. There was no bacterial growth after disinfection with an alcohol-impregnated swab.

Implications for clinical practice: The majority of needleless connectors had bacterial contamination before disinfection. Needleless connectors should be disinfected for 30 seconds before use, particularly in immunocompromised patients. However, the use of needleless connectors with antiseptic barrier caps may be a more practical and effective solution instead.

Keywords: Bacteria; Central venous catheter; Colonization; Contamination; Decontamination; Disinfection; Multidrug-resistant organisms; Needleless connector.