[Microbiology of surgical site infections in abdominal tract surgery patients].

Introduction: Knowledge of the microbiology of surgical infections after abdominal surgery can be of use when prescribing effective empirical antibiotic treatments.

Method: Analysis of surgical infections after abdominal surgery in patients enrolled in the Prevalence of Infections in Spanish Hospitals (EPINE) corresponding to the years 1999-2006.

Results: During the period of the study, 2,280 patients who were subjected to upper or lower abdominal tract surgery were diagnosed with an infection at the surgical site (SSI). Eight hundred and eighty three patients (37%) had an operation of the upper abdominal tract (gastric, hepatobiliary, and pancreatic surgery) and 1,447 patients (63%) lower abdominal tract surgery (appendectomy and colon surgery). A total of 2,617 bacterial species were isolated in the 2,280 patients included in the analysis. The most frequent microorganisms isolated were, Escherichia coli (28%), Enterococcus spp. (15%), Streptococcus spp. (8%), Pseudomonas aeruginosa (7%), and Staphylococcus aureus (5%, resistant to methicillin 2%). In the surgical infections after upper abdominal tract procedures, there were a higher proportion of isolations of staphylococci, Klebsiella pneumoniae, Enterobacter spp., Acinetobacter spp. and Candida albicans and less Escherichia coli, Bacteroides fragilis and Clostridium spp.

Conclusion: The microbiology of SSI produced after upper abdominal tract surgery did not show any significant differences compared to those of the lower tract. However, more cases of SSI were detected due to staphylococci, Klebsiella pneumoniae, Enterobacter spp., Acinetobacter spp. and Candida albicans and less caused by Escherichia coli, Bacteroides fragilis and Clostridium spp.