Bacterial recovery using sonication versus swabbing of titanium and stainless steel implants inoculated with Staphylococcus pseudintermedius or Pseudomonas aeruginosa

Summary

Objective: To evaluate the use of sonication to improve recovery of bacteria from metal discs infected with bacteria commonly associated with implant infections in veterinary medicine.

Methods: In vitro study in which sterile titanium (Ti6Al4V) and stainless steel (AIS1316-L) discs were incubated with either Staphylococcus pseudintermedius or Pseudomonas aeruginosa for 24 hours. The following three groups were compared: 1) the sonication group involved immersing the discs in sterile saline and sonicating for five minutes; 2) the sham group was considered a negative control in which the discs were immersed in saline for five minutes without sonication; and 3) the swab group involved systematically swabbing the implant with a sterile culturette. All samples were plated on blood agar and incubated for 24 hours. Colonies were then counted and compared.

Results: For both species of bacteria, there was a significant increase in bacterial colonies isolated using sonication compared to the other two study groups (p = 0.0001). No differences in bacterial growth were found between the two types of metal implants. There was a significant increase in bacterial colony counts for S. pseudintermedius when comparing the swab group versus the sham group, but this was not significant for P. aeruginosa.

Clinical significance: Sonication significantly improves recovery of bacteria commonly associated with veterinary implant-associated surgical site infections compared to swabbing of implants in vitro. A prospective clinical evaluation is indicated to determine the in vivo efficacy of sonication in veterinary patients.

Keywords

Bacterial biofilm - orthopaedic implants - surgical site infection - sonication

• References

• 1 Weese JS. A review of post-operative infections in veterinary orthopedic surgery. Vet Comp Orthop Traumatol 2008; 21: 99-105.
• 2 Fitzpatrick N, Solano MA. Predictive variables for complications after TPLO with stifle inspection by arthrotomy in 1000 consecutive dogs. Vet Surg 2010; 39: 460-474.
• 3 Nicoll C, Singh A, Weese JS. Economic impact of tibial plateau leveling osteotomy surgical site infection in dogs. Vet Surg 2014; 1-4.
• 4 Gatineau M, Dupuis J, Plante J. et al. Retrospective study of 476 tibial plateau leveling osteotomy procedures. Vet Comp Orthop Traumatol 2011; 24: 333-341.
• 5 Frey TN, Hoelzler MG, Scavelli TD. et al. Risk factors for surgical site infection-inflammation in dogs undergoing surgery for rupture of the cranial cruciate ligament: 902 cases 2005-2006. J Am Vet Med Assoc 2010; 236: 88-94.
• 6 Pacchiana PD, Morris E, Gillings SL. et al. Surgical and postoperative complications associated with tibial plateau leveling osteotomy in dogs with cranial cruciate ligament rupture: 397 cases 1998-2001. J Am Vet Med Assoc 2003; 222: 184-193.
• 7 Corr SA, Brown C. A comparison of outcomes following tibial plateau levelling osteotomy and cranial tibial wedge osteotomy procedures. Vet Comp Orthop Traumatol 2007; 20: 312-319.
• 8 Bergh MS, Peirone B. Complications of tibial plateau levelling osteotomy in dogs. Vet Comp Orthop Traumatol 2012; 25: 349-358.
• 9 Bjerkan G, Witso E, Bergh K. Sonication is superior to scraping for retrieval of bacteria in biofilm on titanium and steel surfaces in vitro. Acta Orthopaedica 2009; 80: 245-250.
• 10 Neut D, van Jr Horn , van Kooten TG. et al. Detection of biomaterial-associated infections in orthopaedic joint implants. Clin Orthop 2003; 413: 261-268.
• 11 Portillo ME, Salvadó M, Alier A. et al. Advantages of sonication fluid culture for the diagnosis of prosthetic joint infection. J Infect 2014; 69: 35-41.
• 12 Pandey R, Berendt AR, Athanasou NA. Histological and microbiological findings in non-infected and infected revision arthroplasty tissues. Arch Orthop Trauma Surg 2000; 120: 570-574.
• 13 Tunney MM, Patrick S, Curran MD. et al. Detection of prosthetic hip infection at revision arthroplasty by immunofluorescence microscopy and PCR amplification of the bacterial 16S rRNA gene. J Clin Microbiol 1999; 37: 3281-3290.
• 14 Donlan RM. New approaches for the characterization of prosthetic joint biofilms. Clin Orthop Relat Res 2005; 437: 12-19.
• 15 Shen H, Tang J, Wang Q. et al. Sonication of explanted prosthesis combined with incubation in BD Bactec bottles for pathogen-based diagnosis of prosthetic joint infection. J Clin Microbiol 2015; 53: 777-781.
• 16 Trampuz A, Piper KE, Jacobson MJ. et al. Sonication of removed hip and knee prostheses for diagnosis of infection. New Engl J Med 2007; 357: 654-663.
• 17 Holinka J, Bauer L, Hirschi AM. Sonication cultures of explanted components as an add-on test to routinely conducted microbiological diagnostics improve pathogen detection. J Orthop Res 2011; 29: 617-622.
• 18 Kobayashi N, Bauer TW, Tuohy MJ. et al. Brief ultrasonication improves detection of biofilm-formative bacteria around a metal implant. Clin Orthop Relat Res 2006; 457: 210-213.
• 19 Tunney MM, Patrick S, Gorman SP. et al. Improved detection of infection in hip replacements: a currently underestimated problem. J Bone Joint Surg Br 1998; 80: 568-572.
• 20 Savicky R, Beale B, Murtaugh R. et al. Outcome following removal of TPLO implants with surgical site infection. Vet Comp Orthop Traumatol 2013; 26: 260-265.
• 21 Jordan RP, Marsh L, Ayre WN. et al. An assessment of early colonization of implant-abutment metal surfaces by single species and co-cultured bacterial periodontal pathogens. J Dent 2016; 53: 54-72.
• 22 Diribe O, Thomas S, AbuOun M. et al. Genotypic relatedness and characterization of Staphylococcus pseudintermedius associated with post-operative surgical infections in dogs. J Med Microbiol 2015; 64: 1074-1081.
• 23 Donlan RM. Biofilm formation: a clinically relevant microbiological process. Clin Infect Dis 2001; 33: 1387-1392.
• 24 Revdiwala S, Rajdev BM, Mulla S. Characterization of bacterial etiologic agents of biofilm formation in medical devices in critical care setup. Crit Care Res Pract 2012; 2012: 945805.
• 25 Arens S, Schlegel U, Printzen G. et al. Influence of materials for fixation implants on local infection. J Bone Joint Surg 1996; 78: B647-651.
• 26 Sheehan E, McKenna J, Mulhall KJ. et al. Adhesion of Staphylococcus to orthopaedic metals, an in vivo study. J Orthop Res 2004; 22: 39-43.
• 27 Hudetz D, Hudetz SU, Harris LG. et al. Weak effect of metal type and ica genes on staphylococcal infection of titanium and stainless steel implants. Clin Microbiol Infect 2008; 14: 1135-1145.
• 28 Sutton S. Accuracy of plate counts. Journal of Validation Technology 2011; 17: 42-46.