Efficacy of endotracheal tube disinfection strategies for elimination of Streptococcus zooepidemicus and Bordetella bronchiseptica

J Am Vet Med Assoc. 2015 Nov 1;247(9):1033-6. doi: 10.2460/javma.247.9.1033.


Objective: To evaluate the efficacy of various endotracheal tube disinfection strategies for elimination of Streptococcus zooepidemicus and Bordetella bronchiseptica.

Design: Experimental in vitro study.

Sample: 12 sterile endotracheal tubes.

Procedures: Endotracheal tubes were inoculated with S zooepidemicus or B bronchiseptica and subjected to 1 of 5 treatments (spraying with accelerated hydrogen peroxide solution [AHP] or soaking in one of the following: AHP, 0.5% chlorhexidine gluconate solution [CHG], 0.3% triclosan-containing soap solution, or tap water) or left untreated (controls). After 5 minutes, tubes were rinsed with water and swabbed for direct and enrichment culture. Culture results were scored semiquantitatively. Each isolate was tested separately (10 endotracheal tubes/isolate/treatment).

Results: No growth was identified by direct culture of any samples collected from CHG-treated endotracheal tubes, whereas S zooepidemicus and B bronchiseptica were each identified from 1 of 10 tubes sprayed or soaked with AHP and from all tubes (10/10 each) treated by other methods or used as controls. The CHG and AHP treatments resulted in significantly lower median growth scores after direct culture than did other treatments. After enrichment culture, samples from CHG-treated tubes had significantly lower growth scores than samples from AHP-treated tubes, which had significantly lower scores than samples from other treatment groups.

Conclusions and clinical relevance: High-level disinfection (ie, elimination of all vegetative bacterial growth) was not achieved with any treatment tested. Although optimal approaches are not known, processing of endotracheal tubes with CHG or AHP appears to be the best approach when sterilization is not feasible.

MeSH terms

  • Anti-Infective Agents, Local / pharmacology*
  • Bordetella bronchiseptica / drug effects*
  • Chlorhexidine / analogs & derivatives
  • Chlorhexidine / pharmacology
  • Colony Count, Microbial
  • Disinfectants / pharmacology*
  • Disinfection / methods
  • Equipment Contamination
  • Hydrogen Peroxide / pharmacology
  • Intubation, Intratracheal / instrumentation
  • Intubation, Intratracheal / veterinary*
  • Streptococcus equi / drug effects*
  • Triclosan / pharmacology


  • Anti-Infective Agents, Local
  • Disinfectants
  • Triclosan
  • Hydrogen Peroxide
  • chlorhexidine gluconate
  • Chlorhexidine