[The effect of low-intensity pulsed sound waves delivered by the Exogen device on Staphylococcus aureus morphology and genetics].
OBJECTIVE
We investigated the effect of low-intensity pulsed sound waves delivered by the Exogen device, which is recommended for the treatment of delayed union and nonunion in orthopedic surgery, on the colony number, antimicrobial susceptibility, bacterial morphology, and genetics of Staphylococcus aureus, which is a frequent pathogen in orthopedic infections.


METHODS
Thirty tubes containing 0.5 McFarland suspensions of S. aureus (ATCC 25923) were used. Fifteen tubes forming the test group were subjected to low-intensity sound waves by the Exogen device for 20 minutes. The remaining 15 tubes were untreated as controls. The two groups were then compared with respect to colony number, antibiotic susceptibility, and genotypic properties. The tubes were examined histologically by electron microscopy.


RESULTS
The test tubes treated with sound waves showed a significantly lower number of bacteria colonies compared to the control tubes (p<0.001). The two groups were similar with respect to antibiotic susceptibility and genotypic properties. Bacterial cell wall structure in the control group was of normal appearance, whereas partial destruction and break-up were observed in test samples. Bacterial cell wall thickness was significantly higher in the test group compared to the control group (41.54 nm and 24.27 nm, respectively; p<0.001).


CONCLUSIONS
Low-intensity sound waves may be beneficial as a prophylactic measure to prevent infections in primary orthopedic operations and as an adjuvant therapy for infected nonunions.
Ayan
Irfan
I
Department of Orthopedics and Traumatology, Medicine Faculty of Mersin University, Mersin, Turkey. irfanayan@hotmail.com
Aslan
Gönül
G
Cömelekoğlu
Ulkü
U
Yilmaz
Nejat
N
Colak
Mehmet
M
D015169:Colony Count, Microbial; D024881:Drug Resistance, Bacterial; D006801:Humans; D019637:Orthopedic Procedures / Q000009:adverse effects; D010000:Osteitis / Q000517:prevention & control*; D016459:Prosthesis-Related Infections / Q000517:prevention & control*; D013016:Sound; D013203:Staphylococcal Infections / Q000517:prevention & control*; D013211:Staphylococcus aureus / Q000235:genetics / Q000254:growth & development* / Q000472:pathogenicity; D013530:Surgical Wound Infection / Q000517:prevention & control*; D016896:Treatment Outcome