A pilot study of the in vitro antimicrobial activity and in vivo residual activity of chlorhexidine and acetic acid/boric acid impregnated cleansing wipes.

BACKGROUND: Topical antimicrobials are recommended for first line treatment of surface and superficial infections in dogs. This is especially important given the increasing prevalence of antimicrobial resistant infections. Antimicrobial wipes have become popular, but there are a lack of controlled studies assessing their in vitro antimicrobial and in vivo residual activity. We aimed to assess the antimicrobial efficacy of two commercial antimicrobial wipes against frequently isolated pathogens. Ten clinical and one reference isolate each of meticillin-susceptible Staphylococcus pseudintermedius (MSSP), meticillin-resistant S. pseudintermedius (MRSP), Escherichia coli (EC), extended spectrum beta-lactamase (ESBL) producing E. coli (ESBL-EC), Pseudomonas aeruginosa (PA) and Malassezia pachydermatis (MP) were tested using a modified Kirby-Bauer technique. Each isolate was tested against 6 mm discs of chlorhexidine (CHX) and acetic acid/boric acid (AABA) wipes, and positive and negative controls either overnight (bacteria) or for 3 days (Malassezia). Healthy dogs were treated with the wipes and distilled water on a randomised flank (n = 5 each). Hair samples (1 cm; 0.1 g) taken at days 0, 1 and 3 were inoculated with an isolate of each organism. Zones of inhibition (ZI) were measured. RESULTS: All isolates produced confluent growth with AABA and control wipes, except for the cleansing wipes and MP (median ZI 12 mm; 95% CI 8.2-15.8). The median (95% CI) CHX wipe ZIs (mm) were: MP 48.0 (47.0-49.0), MSSP 15.6 (14.2-17.0), MRSP 14.0 (13.6-14.4), EC 13.6 (12.0-15.2) and ESBL-EC 10.0 (9.4-10.6). PA showed confluent growth. The differences between the bacterial isolates was significant (Kruskal-Wallis p < 0.0001; post-tests MSSP = MRSP = EC > EBSL-EC > PA). Confluent growth was visible with all the hair samples. CONCLUSION: CHX but not AABA showed in vitro efficacy against MSSP, MRSP, EC and MP. ESBL-EC were less susceptible and there was no activity against PA. There was no residual activity on hair. Additional studies are required to determine efficacy of these products in clinically affected patients.

Comparable efficacy of a topical 0.0584% hydrocortisone aceponate spray and oral ciclosporin in treating canine atopic dermatitis.

This study compared the efficacy of a 0.0584% hydrocortisone aceponate (HCA) spray (Cortavance(®); Virbac SA) and ciclosporin (Atopica(®); Novartis Animal Health) in canine atopic dermatitis in a single-blind randomized controlled trial. Dogs received HCA (two sprays/100 cm(2); n=24) or ciclosporin (5 mg/kg; n=21). Canine Atopic Dermatitis Extent and Severity Index (CADESI)-03, pruritus (visual analog scale with grade descriptors) and owner scores (5-point scales) were recorded every 28 days for 84 days. Intention-to-treat data were analysed. CADESI-03 and pruritus significantly decreased over time (P<0.0001), but there was no difference between the treatment groups (P=0.91 and P=0.52, respectively). Similar proportions of HCA- and ciclosporin-treated dogs achieved ≥50% reductions in CADESI-03 and pruritus scores at 28 days (CADESI-03 58.3 and 57.1%, P=0.76; pruritus 33.3 and 38.1%, P=1.0), 56 days (CADESI-03 70.8 and 81.0%, P=1.0; pruritus 62.5 and 57.1%, P=1.0) and 84 days (CADESI-03 75 and 85.7%, P=0.72; pruritus 65.2 and 57.1%, P=0.76). The CADESI-03 and pruritus scores were close to equivalence (0.47 and 0.51, respectively). By 84 days, every-other-day or twice-weekly therapy was achieved in 13 of 24 HCA- and 12 of 21 ciclosporin-treated dogs (P=0.85). There were no significant differences in scores for efficacy (P=0.82), tolerance (P=0.62) and ease of administration (P=0.25). Scores for tolerance (0.49) and administration (0.46) were close to equivalence. The score for efficacy favoured HCA (0.68). Mild adverse events were noted in six of 21 ciclosporin and none of 24 HCA dogs (P=0.008). Five HCA-treated dogs and three ciclosporin-treated dogs were prematurely withdrawn (P=0.7). In conclusion, HCA and ciclosporin proved equally effective in treating canine atopic dermatitis for up to 84 days.

Efficacy of a 0.0584% hydrocortisone aceponate spray in presumed feline allergic dermatitis: an open label pilot study.

This study evaluated the efficacy of a 0.0584% hydrocortisone aceponate (HCA) spray (Cortavance(®); Virbac SA) in 10 cats with presumed allergic dermatitis. The cats initially received two sprays/100 cm(2) of skin once daily. Clinical lesions (a Feline Dermatitis Extent and Severity Index; FeDESI), pruritus (10 cm visual analog scale with grade descriptors) and owner assessments of efficacy, tolerance and ease of use (from 1=very poor to 5=excellent) were assessed every 14 days. The frequency of treatment was reduced after day 28 in cats with a >50% reduction in FeDESI and pruritus scores. One cat was lost to follow up at day 28 and two at day 42. Intention-to-treat data were analysed. The FeDESI [mean (SD): day 0, 42.2 (15.7) and day 56, 9.9 (11.7); P<0.0001] and pruritus scores [day 0, 61.2 mm (20.1) and day 56, 14.6 mm (16.1); P<0.0001] significantly decreased throughout the trial. The owner scores for tolerance [median (range): day 14, 4 (1-5) and day 56, 4 (3-5); P=0.003] and ease of administration [day 14, 3 (2-5) and day 56, 4 (2-5); P=0.02] significantly increased during the trial, but there was no significant change in efficacy scores [day 14, 4 (3-5) and day 56, 4 (2-5); P=0.5]. There were no adverse effects attributable to the HCA spray, no significant changes in weight [mean (SD): day 0, 5.0 kg (1.4) and day 56, 5.0 kg (1.6); P=0.51] and no significant changes in haematology, biochemistry or urinalysis (n=4). Six cats required every-other-day treatment and four required daily treatment. In conclusion, HCA spray appeared to be effective and safe in these cats, although it is not licensed for use in this species.

Investigation of the in vitro antimicrobial activity of triclosan-coated suture material on bacteria commonly isolated from wounds in dogs.

OBJECTIVE: To investigate in vitro effects of triclosan coating of suture materials on the growth of clinically relevant bacteria isolated from wounds in dogs. SAMPLE: 6 types of suture material and 10 isolates each of methicillin-susceptible Staphylococcus pseudintermedius, methicillin-resistant S pseudintermedius, Escherichia coli, and AmpC ß-lactamase and extended-spectrum ß-lactamase-producing E coli from clinical wound infections. PROCEDURES: Isolates were cultured on Mueller-Hinton agar with 3 types of triclosan-coated suture, uncoated counterparts of the same suture types, and positive and negative controls. Zones of inhibition (ZOIs) were measured after overnight incubation. Sustained antimicrobial activity assays were performed with susceptible isolates. The ZOI measurements and durations of sustained antimicrobial activity were compared among suture types and isolates by statistical methods. Suture surface characteristics and bacterial adherence were evaluated qualitatively with scanning electron microscopy. RESULTS: ZOIs were generated only by triclosan-coated materials; triclosan-coated suture had sustained antimicrobial activity (inhibition) for 3 to 29 days against all tested pathogens. The ZOIs around triclosan-coated suture were significantly greater for S pseudintermedius isolates than for E coli isolates. Bacterial adherence to uncoated polyglactin-910 was greatest, followed by triclosan-coated polyglactin-910, and then uncoated monofilament sutures, with least adherence to coated monofilament sutures. CONCLUSIONS AND CLINICAL RELEVANCE: Surface characteristics of suture materials may be as important or more important than triclosan coating for microbial inhibition; however, triclosan coating appeared to affect bacterial adherence for multifilament sutures. Triclosan-coated, particularly monofilament, sutures inhibited pathogens commonly isolated from wounds of dogs, including multidrug-resistant bacteria. Further studies are required to assess clinical efficacy of triclosan-coated suture materials in vivo.