Potentiating effect of EDTA-Tris on the activity of antibiotics against resistant bacteria associated with otitis, dermatitis and cystitis.
J Small Animal Practice 1997 Jun;38(6):243-5
Farca AM ; Piromalli G ; Maffei F ; Re G
Department of Animal Pathology, University of Turin, Italy.
- Synergistic effects of the combination of EDTA-tromethamine (EDTA-Tris) and three antimicrobial agents (cephaloridine, kanendomycin and enrofloxacin) against resistant Gram-positive and Gram-negative bacteria are reported. Bacteria were isolated from eight cases of chronic otitis externa, five cases of chronic dermatitis and four cases of recurrent cystitis in dogs which had previously been treated with one of the three antibiotics without success. Animals exposed to EDTA-tromethamine plus the antibiotic recovered completely within 10 days, and were controlled clinically and bacteriologically for 180 days. Local irrigation with EDTA-tromethamine solution was well tolerated and no side effects were recorded. (Author Abstract)
Treating Canine otitis externa with an EDTA-TRIS-SDS combination
Vet Med 83[10] : 1088-1091 Oct'88 24 Refs
1Richard E. Wooley, DVM, Ph.D.; Harry W. Dickerson, BVSc, PhD; William R. Engen, DVM
1Dept of Med Microbiology, College of Vet Med, Univ of Georgia, Athens, GA 30602
-Experimental study reports on the in vitro activity of a combination of 5.0 mM ethylenediaminetetraacetate [EDTA], 50.0 mM tris[hydroxymethyl]aminomethane [TRIS], and 0.05% sodium dodecyl sulfate [SDS], with a pH = 8.0, against Bacillus spp, Staphylococcus aureus, Candida spp, Pseudomonas aeruginosa, E. coli, Proteus vulgaris, Trichosporon spp., and an alpha Streptococcus. The procedure for evaluating synergy between EDTA-TRIS and SDS is described.
In vivo evaluation of the combination in clinical cases of otitis externa in 24 dogs is reported. Fifteen cases were acute; nine were chronic. All were evaluated with bacterial culture before and after treatment.
TREATMENT consisted of applying lavage solution to the ears TID until resolution or for 3 weeks if no clinical response occurred. Method of application/treatment is not described. The study was a clinical trial, not a controlled study. Dogs were examined for irritation of the ears after treatment.
RESULTS from the in vitro studies showed that the EDTA-TRIS- SDS had synergistic activity against Bacillus spp, P. aeruginosa, E. coli, and P. vulgaris. Additive activity was found against S. aureus, Candida spp and Trichosporon spp.
In the clinical trials, 23 of 24 cases were resolved; no adverse effects were seen; duration of follow-up is not specified. The one case that failed to respond was a chronic mixed infection of E. coli and Proteus spp, inflammation was reduced, but the infection persisted. Most cases responded within 1 week, but P. aeruginosa infections required 1 - 3 weeks of treatment.
Graphs and tables accompany the text Resistant Pseudomonas Otitis, Antibiotic Choices
- Re: reistant pseudomonas otiti 98-03-31 Lou E Gee
I have been using an EDTA-tris pre-treatment for resistant, difficult
pseudomonas cases. EDTA-tris damages the cell membranes of the gram negative bacteria so that the topical antibiotics can penetrate and kill the bacteria. Fill the ear canal(s) with the EDTA-tris solution and allow it to remain in the ear for 15 minutes. Then wipe out whatever comes out and instill the antibiotic solution.
Even though your culture may show resistance to most antibiotics, pretreatment with EDTA-tris makes this issue less important. You can probably use any of the fluroquinolones topically, even though your sensitivity didn't indicate sensitivity to them. Remember that cultures are taken reflect the blood levels of an antibiotic and that if they are given topically they will be typically 100-1000x that in the blood. Lou Gotthelf
Articles of Interest
The above information was obtained from VIN and is reproduced with their permission.
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