Patologie cutanee complicate da batteri nel cane: diagnosi e follow up. valutazione degli aspetti di farmaco resistenza

Abstract

During the 3 years period of the PhD (2009-2011) a study on “Skin diseases complicated by bacteria in dog: diagnosis and follow up. Evaluation of antibiotic resistance “ has been developed. The study was conducted at the Department of Animal Health of the Veterinary Medicine Faculty of Parma. As first opinion cases, 204 dermatological canine patients have been examined. Subsequently, the same patients were re-examined every 3 weeks, depending on the owner compliance. The cases have been selected among canine patients with pathologies of the skin and cutaneous annexes. On these patients a dermatological examination has been carried out, cultural examination and antibiotic sensitivity testing by Kirby-Bauer method on the bacterial isolates. A panel of 27 antibiotic drugs were tested. Among a total of 121 bacterial isolates, a number of 96 (80%) were belonging to the Staphylococcus genus. Other isolates belonged to the Enterobacteriaceae family (n.15), Pseudomonas aeruginosa (n. 6) and Pasteurella multocida (n. 3). A number of 34 staphyloccal strains were resistant to methicillin, wereas a number of 43 staphyloccal strains were resistant to oxacillin. Discordance were noted in the evaluation of methicillin /oxacillin activity in 20 cases. MecA expression, which confer resistance to beta-lactam antibiotics, was confirmed in 17 cases by evaluation of the presence of the PBP2a by a latex agglutination test. Also the pathogenicity of 10 haemolytic strains of Staphylococcus epidermidis isolates and their antibiotic resistances have been evaluated. For staphylococcal strains we noticed antibiotic activity in >50% for amoxicillin + clavulanic acid, cefadroxil, cefalexin, cloramphenicol, cloxacillin, doxiciclin, mupirocin, rifampicin and vancomicin; on the opposite, fluorochinolons had an activity on <50% of the isolated staphylococcal strains. 4 The application of a correct diagnostic protocol is strongly suggested to avoid the therapeutic failure and the emergence of antibiotic resistances , particularly in consideration of the zoonotic role of methicillin/oxacillin staphylococcal strain. This protocol is based on a complete dermatological evaluation, cultural examination and antibiotic testing.