Identification of Bacteria and Sterilization of Crustacean Exoskeleton Used as a Biomaterial

摘要

Derivatives of the crustacean exoskeleton like chitin have a long history of being used as biomaterials. In the BONE/CRAB lab, the blue claw crab exoskeleton is our biomaterial of choice for a possible bone implant material. The blue claw crustacean, Callinectes sapidus, is found in the Chesapeake Bay. Chitinolytic bacteria, such as those belonging to the Vibrio and Bacillus genera, are common to marine crustaceans. Previous in vitro studies in our lab indicated that bacterial contamination is a major concern. One of the fundamental considerations with the use of an implant biomaterial is sterilization. Materials implanted into the human body must be sterile to avoid subsequent infection or other more serious consequences. An effective sterilization method strikes a balance between the required sterility level and minimum detrimental effect on the properties of the biomaterial while being cost-effective, simple, and readily available. The objective of this study was to isolate, identify bacterial contaminants and develop the best sterilization method for those bacteria found on blue claw crab exoskeleton. Bacteria belonging to the genera Bacillus were identified based on bacterial growth morphologies of dry, dull, raised, rough, and white-grey appearance on LB agar. Bacillus members form endospores which are difficult to eliminate and poses a significant concern for implantable materials. There was no bacterial growth on the TCBS agar plates which is a differential and selective media for Vibrio species. Antimicrobial susceptibility tests were conducted to measure the effectiveness of 70% isopropyl alcohol, povidone-iodine, and household bleach against the bacteria found. The susceptibility tests revealed sensitivities towards the compounds studied. Bacterial identification and susceptibility provide vital guidance to the best method to sterilize while maintaining biological performance. Further studies will evaluate the effect the sterilization protocol has on the physical, chemical, and biological properties of the implant material.