In Vitro Evaluation of E. coli And S. epidermidis Adhesion on Dressing Materials Used in Hypospadias Repair

Abstract

Background An in vitro study was performed to evaluate the adherence of Escherichia coli and Staphylococcus epidermidis to different dressing materials.

Methods Hydrophyl gauze swab (GS), sterile flax swab (FS), and their nitrofurazone (Furacin (R)) absorbed forms (GSF and FSF), sterile paraffin-covered gauze with chlorhexidine acetate (0.5 %) (Bactigrass (R), BG), and semipermeable transparent film gauze (Tegaderm (R), TG) were used in the study. A 1 cm(2) of each material was placed in culture plates, and E. coli ATCC 25922 and S. epidermidis ATCC 12228 were suspended in each plate. After 24, 48 h, and 1 week of incubation period, colony counts were calculated in colony-forming units (CFU) per square centimeter unit. Bacterial adhesion was compared between groups, and each dressing material was also compared for different incubation periods (24, 48 h, and 1 week).

Results The colony counts were significantly decreased in GSF and FSF groups (Kruskal-Wallis test, p < 0.05). There was no difference for E. coli adhesion in GS, FS, BG, and TG groups (p > 0.05). The significant difference detected for S. epidermidis adhesion in the first 24 to 48 h could not be detected at the end of a 1-week period. There was no statistical difference in groups when compared for 24-, 48-h, and 1-week periods of incubations (Wilcoxon signed-rank test, p > 0.05). In BG group, E. coli adhesion was increased, and S. epidermidis adhesion was decreased without a significant difference at the end of a 1-week period (p > 0.05).

Conclusions Nitrofurazone absorbed sterile gauze materials have less bacterial adhesion. In vitro adhesion of E. coli and S. epidermidis did not differ between the 24-h and 1-week period. E. coli adhesion to BG can be increased if the duration of dressing prolonged up to a 1-week period. Level of Evidence: Not ratable.