Adherence and Biofilm Formation of Staphylococcus epidermidis and Mycobacterium tuberculosis on Spinal Implant

Chung, Yang Guk; Ha, Kee Yong

Abstract

STUDY DESIGN: Bacterial adherence and biofilm formation in implant associated infection may depend on species of microor-ganism, types of strains, the physical or chemical characteristics of the implant surfaces.
OBJECTIVES
To evaluate the differences of adherence and biofilm formation between S. epidermidis and M. tuberculosis on smooth surfaced or rough surfaced stainless steel and titanium alloy, respectively. SUMMARY OF LITERATURE REVIEW: In implant associated infections, bacteria in biofilm are resistent to antibiotics or host defence mechanism and removal of implants is usually necessary to eradecate infection. On contrary, spinal instrumentation with complete debridement and antituberculosis chemotherapy is a safe procedure for spinal tuberculosis.
MATERIALS AND METHODS
S. epidermidis and M. tuberculosis were cultured with 4 types of rod segments which consisted of smooth and rough surfaced stainless steel and titanium alloy, respectively. After isolation with trypsin treatment and culture on plate media, colony forming units (CFUs) were counted. The feature of adherence and biofilm formation were observed under scanning electron microscopy (SEM).
RESULTS
Biofilm forming S. epidermidis showed heavy adhesion and multiplication on surface of all 4 rod segments, 16.5 times more CFUs than biofilm non-forming ones, especially on smooth surfaced stainless steel. On SEM field, there were many aggregated microcolonies with thick amorphous biofilm in biofilm forming S. epidermidis and much less in biofilm non-forming S. epidermidis. M. tuberculosis rarely adhered to metal surfaces. On SEM, there were few tubercle bacilli and scanty biofilm for-mation.
CONCLUSIONS
Biofilm may play an important role in adhesion and multiplication of S. epidermidis but adherence and biofilm iformation of M. tuberculosis on implant surface are less likely and it can provide the basis of instrumentation in spinal tubercu-losis.