In vitro analysis of the effects of biomaterial adherence on a Staphylococcus epidermidis strain's sensitivity to cephaloridine

✍ Scribed by Masayoshi Oga; Tuyoshi Arizono; Youichi Sugioka; Paul T. Naylor; Quentin N. Myrvik; Dr. Anthony G. Gristina

• Publisher: Wiley (John Wiley & Sons)
• Year: 1992
• Tongue: English
• Weight: 438 KB
• Volume: 3
• Category: Article
• ISSN: 1045-4861
• DOI: 10.1002/jab.770030205

✦ Synopsis

Abstract

This study examined the effects biomaterial adherence had on Staphylococcus epidermidis‐46 morphology and sensitivity to the antibiotic cephaloridine. Polymethylmethacrylate (PMMA) discs served as the biomaterial substratum in this study. Suspension cultures of SE‐46 at 10^8^ CFU/mL were allowed to adhere to PMMA discs for 2, 6, or 12 h prior to exposure to cephaloridine at 250 μg/mL, which is 500 times greater than the MIC of 0.5 μg/mL. After a 24‐h exposure to the antibiotic viable bacteria adherent to the disc were removed and counted. Those data revealed that at shorter adherence times a larger percentage of the adherent organism were erradicated by antibiotic exposure, 83.6%versus 15.6%for 2‐h and 12‐h adherencetimes, respectively. Although a significant percent of the organisms were killed with short adherence times, the organism still persisted in the face of high concentrations of cephaloridine. Scanning electron micrographs of organism adherent for 2 and 12 h revealed distinct morphological changes in the extracellular matrix indicating increased matrix production with longer adherence. Thus, these data reveal that adherence to biomaterials provides a protected environment for the bacteria and the time an organism is adherent to a biomaterial surface prior to antibiotic exposure can also increase the organism's resistance to antibiotics.