ROLE OF THE PREAXILLARY FLORA IN PACEMAKER INFECTIONS - A PROSPECTIVE-STUDY

Background-infection remains a severe complication after pacemaker imp lantation. The purpose of our prospective study was to evaluate the ro le of the local bacteriologic flora in its occurrence. Methods and Res ults-Specimens were collected at the site of implantation for culture from the skin and the pocket before and after insertion in a consecuti ve series of patients who underwent elective permanent pacemaker impla ntation. Microorganisms isolated both at the time of insertion and of any potentially infective complication were compared by using conventi onal speciation and ribotyping. There were 103 patients (67 men and 36 women) whose age ranged from 16 to 93 years (mean+/-SD, 67+/-15). At the time of pacemaker implantation, a total of 267 isolates were ident ified. The majority (85%) were staphylococci. During a mean follow-up of 16.5 months (range, 1 to 24), infection occurred in four patients ( 3.9%). In two of them, an isolate of Staphylococcus schleiferi was rec ognized by molecular method as identical to the one previously found i n the pacemaker pocket. In one patient, Staphylococcus aureus, an orga nism that was absent at the time of pacemaker insertion, was isolated. In another patient, a Staphylococcus epidermidis was identified both at the time of pacemaker insertion and when erosion occurred; however, their antibiotic resistance profiles were different. Conclusions-This study strongly supports the hypothesis that pacemaker-related infecti ons are mainly due to local contamination during implantation. S schle iferi appears to play an underestimated role in infectious colonizatio n of implanted biomaterials and should be regarded as an important opp ortunistic pathogen.