Oral microflora in reconstructive surgery for head and neck cancer

Objectives: Reconstructive surgery for head and neck cancer is one of surgeries at high risk for surgical site infections because bacterial contamination by the indigenous oral microflora occurs easily. It has been suggested that professional oral hygiene prior to surgery decreases the incidence of the postoperative infection. However, the relationship between professional oral hygiene and the change of oral microflora is not clear. The aim of this study was to clarify the change of the oral microflora following professional oral hygiene prior to surgery for head and neck cancer. Methods: Six patients who underwent surgery for head and neck cancer at Shizuoka Cancer Center Hospital were enrolled in this study. Both swab sample from mucosal surface around the incision site and saliva were collected at three time points (before and after professional oral hygiene prior to the surgery, and 1 week after surgery). Each sample was evaluated for morphology by microscopic observation, total bacterial number, and quantification of periodontal pathogens by real-time PCR. Identification of bacteria was performed by using API kits. All subjects had received antibiotic prophylaxis for three days after surgery. Results: Prevalence of cocci has been increased in saliva sample after professional oral hygiene in 5 of 6 subjects. After surgery, cocci and rods occupied the majority in both saliva and swab samples. A total of 705 colonies were isolated and 568 colonies (76 kinds of strains) were identified by API. The dominant group was Streptococcus genera through three time points, and the most frequently isolated Streptococci were S. mitis and S. sanguis. It was also revealed that the number of detected strains tended to decrease after professional oral hygiene. Conclusion: Oral microflora changes after conducting professional oral hygiene prior to reconstructive surgery for head and neck cancer. This study was supported by the 8020 Promotion Foundation.