gms | German Medical Science

Objective: The development of infection in surgical wounds is a serious complication in neurosurgery as impairment of wound healing may be associated with chronic morbidity. Suture materials may be source of infection by enabling the formation of bacterial biofilm. This study aimed to identify specifically the DNA of bacterial biofilm on suture materials which are routinely used in neurosurgery using polymerase chain reaction (PCR).

Method: Suture specimens were collected from patients, who underwent repeat surgery due to wound healing impairment (group A, n=10) or various reasons (group B, n=10). The sutures from subcutaneous, muscle fascia, and duramater sutures were cut aseptically during surgery and stored immediately at -80°C until processing. To determine the presence of bacteria specimens were processed and DNA was extracted. 500-bp fragments of purified DNA were amplified using universal primers which target hypervariable regions within the bacterial 16S rRNA gene. In the following Single Strain Conformation Polymorphism (SSCP) analysis, genetic information of different bacterial species were separated from each other, isolated, re-amplified, and finally identified using sequencing methods. These results from molecular biology were compared with microbiological routine standard culture findings, which were obtained by intraoperative swab sampling.

Results: In 7 of 10 patients of group A, both gram-positive and gram-negative bacterial were detected. In 5 of 10 patients of group B, PCR detected the presence of DNA of gram-positive bacterial in the suture specimens. The specimens were derived from staphylococcus aureus, propionibacterium acnes, staphylococcus epidermidis, staphylococcus haemolyticus, and escherichia coli. Comparing the results from molecular biology with the routine standard microbiological culture data, revealed that specimens from 2 patients of group A, as well as from 6 patients of group B were both culture and PCR positive.

Conclusions: Our preliminary data suggest that biofilm formation was detected most suture materials and may play an important role in wound healing process in neurosurgery. Even in well-healed wounds, bacterial biofilm could be detected. The formation of bacterial biofilm should be taken into account by neurosurgeons when closing wounds or debriding infected wounds.