THE MICROFLORA ASSOCIATED WITH HUMAN ORAL CARCINOMAS

Both local and systemic infections may complicate the morbidity of pat ients with oral malignant neoplasms, particularly those presenting int raorally. This study investigated the microbial contents of the biofil ms present on the surfaces of oral squamous cell carcinomas. Biofilm s amples were obtained from the central surface of the lesions in 21 pat ients (20 male, 1 female) aged 52.8 (+/- 8.2) years, and from contiguo us healthy mucosa, before any antibiotic therapy or any tumour treatme nt. All lesions were keratinising squamous cell carcinomas with surfac e ulceration. Samples were transported in reduced brain heart infusion (BHI) broth and cultured within Ih of removal, using aerobic and anae robic complete and selective media. The median number of anaerobic col ony forming units (CFU/ml) at the tumour sites (1.6 x 10(8)) was signi ficantly higher than for the healthy (control) mucosa (3.0 x 10(7); P = 0.0001, Wilcoxon); the same was true for aerobes at the tumour sites (1.51 x 10(8)) relative to the controls (2.8 x 10(7); P = 0.0008, Wil coxon). The species isolated in increased numbers at tumour sites were Veillonella, Fusobacterium, Prevotella, Porphyromonas, Actinomyces an d Clostridium (anaerobes), and Haemophilus, Enterobacteriaceae and Str eptococcus spp. (aerobes). Candida albicans was found at eight of the 21 tumour sites, but never at control sites. It was concluded that hum an oral carcinoma surface biofilms harbour significantly increased num bers of aerobes and anaerobes as compared with the healthy mucosal sur face of the same patient. Candida albicans can also be present in thes e biofilms. These findings must be considered in relation to the known predisposition of such patients to systemic infections, and to the un pleasant complications of oral morbidity due to infected lesions. (C) 1998 Elsevier Science Ltd. All rights reserved.