Objective: The purpose of this study was to evaluate the bacterial profile and antimicrobial susceptibility of surgical site infection (SSI) as a basis for optimizing probabilistic antibiotherapy.
Materials and methods: A 6-month transversal retrospective study was carried out at the Souro Sano Hospital Laboratory from November 1st, 2006 to April 30th, 2007. All positive pus samples collected for etiologic diagnosis of SSI were included.
Results: In a series of 681 patients who underwent surgery at the hospital, SSI was observed in 159 cases for an incidence of 23.4%. Pus samples for etiologic diagnosis were collected from 112 patients and led to identification of 103 bacterial strains. The most common strains were enterobacteriaceae in 54.0%, gram-positive cocci in 29.0% and non-fermenting Gram-negative bacilli in 16.5%. Escherichia coli was the most common species (30%) followed by Staphylococcus aureus (16.5%) and Pseudomonas aeroginosa (12.0%). Enterobacteriaceae resistance rates were 71% to amoxicillin, 64% to clavulanic acid-amoxicillin and 15% to third generation cephalosporin. Most S. aureus isolates (85%) were sensitive to methicillin. Non-fermenting Gram-negative bacilli resistance rates were 68.5% to carboxypenicillin and 56% to fluoroquinolones.
Conclusion: These findings indicate that SSI can be treated using third generation cephalosporin-aminosides in combination with oral fluoroquinolones.