Abstract

In this study titanium implants from a patient undergoing spinal column surgery were evaluated to determine cellular morphologies and structures associated with the formation of biofilms. The patient presented postoperative infection by Klebsiella pneumoniae identified through microbiological culture and biochemical tests performed on the implants once they were removed. Subsequently, this person develops multiple infections with Pseudomonas aeruginosa, Burkholderia cepacia, and Candida spp. For observation by scanning electron microscopy (SEM), the implants were fixed in 2.5% glutaraldehyde in sterile PBS and stored at 4 °C. One replica was washed three times with PBS and distilled water, dehydrated in 50% ethanol, dried in an oven for 40 min, and covered with gold. SEM images demonstrated the formation of biofilms with bacterial cell morphologies such as cocci and bacilli of approximately 0.5-1 μm and a well-developed extracellular matrix. The coccoid forms are suggestive of the viable but nonculturable state described for K. pneumoniae as a defense mechanism for its survival, allowing this pathogen to remain for a long time in the biofilm, causing infection to the host and conferring immunological and antibiotic resistance. Crystal-like structures were evident, probably of bacterial origin. This research constitutes the first report that shows the formation of biofilms on titanium implants using SEM, associated with a clinical state of multiple infections and antibiotic resistance. This microscopy technique offers great utility in diagnosing biofilms related to bone implants.