Abstract:

Objective To analyze the composition of and drug resistance in bacteria isolated from the lesions of patients with squamous cell carcinoma of the face and head. Methods Lesional tissue or discharges were obtained from 246 patients with squamous cell carcinoma of the face and head, and subjected to conventional bacterial culture. The isolated bacteria were identified by VITEK TWO automated microbiology system. Antimicrobial susceptibility testing was carried out by Kirby-bauer method. WHONET 5.3 software was utilized for statistical analysis. Results Totally, 294 bacterial strains were isolated, including 168 Gram-negative bacteria （57.1%） and 126 Gram-positive bacteria（42.9%）. The bacterial isolates were predominated by Staphylococcus aureus （21.4%）, followed by Escherichia coli （20.4%）, Staphylococcus epidermidis （18.4%）, Klebsiella-pneumoniae （15.4%） and Pseudomonas aeruginosa （9.5%）. The prevalence was 40%, 26.7%, 42.9% and 55.6% respectively for extended spectrum β lactamases-producing E. coli and K. pneumoniae, methicillin-resistant staphylococcus aureus （MRSA） and methicillin-resistant coagulase-negative S. epidermidis （MRCNS） respectively. P. aeruginosa, E. coli and K. pneumoniae were highly susceptible to imipenem and meropenem, and favorably sensitive to β-lactam and β-lactamase inhibitor combination. No resistance was observed for vancomycin, teicoplanin or linezolid in staphylococci. Conclusions The bacterial isolates from squamous cell carcinoma tissue on the head and neck are predominated by conditional pathogenic bacteria, and the proportion of Gram-negative bacteria is higher than that of Gram-positive bacteria. These isolates seem to be highly resistant to common antibiotics.

Key words: Drug resistance, bacterial