Comparative study of CHROMagar Orientation chromogenic method and conventional microbiological methods of cultivation coupled to otitis externa in domesticated dogs (Canis familiaris Linaeus, 1758)
ABSTRACT. Marotta C.R., Sanavria A. & Scherer P.O. [Comparative study of CHROMagar Orientation chromogenic method and conventional microbiological methods of cultivation coupled to otitis externa in domesticated dogs (Canis familiaris Linaeus, 1758)]. Estudo comparativo de método cromogênico CHROMagar Orientation e métodos de cultivo microbiológicos convencionais associados à otite externa em cães domésticos (Canis familiaris Linaeus, 1758). Revista Brasileira de Medicina Veterinária, 34(4):265-269, 2012. Curso de Pós-Graduação de Medicina Veterinária, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, BR 465 km 7, Seropédica, RJ 23890-000, Brasil. E-mail: carolinamarotta2000@ yahoo.com.br The objective of this study was to evaluate the performance of CHROMagar Orientation compared to conventional means of crops associated with otitis externa in dogs naturally affected household. 72 samples were collected swabs from ear secretions of animals with clinical signs of otitis. For the microbiological identification of gender and samples of the bacterial species were grown in medium CHROMagar Orientation Agar and Blood of 5% sheep Of the 84 bacteria isolated by the usual methods, 27 (32,1%) were Pseudomonas spp., 14 (16.7%), Streptococcus spp., 12 (14.3%) Escherichia coli, 7 (8.3%), Corynebacterium spp., 5 (6%) Staphylococcus intermedius, 7 (8.3%) coagulase-negative Staphylococcus, 8 (9.5%) S. aureus, 2 (2.4%) Proteus sp. and 2 (2.4%) Bacillus sp. Among the 58 bacterial strains isolated by the method CHROMagar orientation, 24 (41.2%) were Pseudomonas spp. displaying cream and translucent colonies, 14 (24.1%) Streptococcus spp. displaying turquoise colonies, 11 (19%) Escherichia coli colonies exhibiting red, 7 (12%) S. aureus golden, opaque, small, 2 (3.4%) Proteus spp. showing brown halo. Among the 72 samples analyzed, 50 (69.4%) had concordant results by both methods, 22 (30.5%) had discrepant results, and 16 (22.2%) could not be identified by any of the two methodologies. In conclusion, CHROMagar Orientation showed a quick and easy means of differentiation of pathogens. Waiver biochemical tests, provides greater autonomy to the veterinary practitioner and greater agility in the routine laboratory contributing to a rapid and associated with in vitro susceptibility testing contributes to establish an early and appropriate treatment protocol.