Otite canina em animais de abrigo municipal: etiologia e perfil de suscetibilidade a antimicrobianos e a óleos essenciais

Abstract

Canine otitis externa is a multifactorial disease whose etiological agents are different bacterial, mycotic and mites. Shelter animals are more prone to illness due to different risk factors that include high population density, stress factors that cause immunodeficiency, trauma, among others. Modulation of risk factors and treatment are the main tools for disease control. However, the empirical and indiscriminate use of antimicrobials has accelerated the natural process of resistance, which has become a problem of great concern in public health, considering that many of the causal agents of the disease have zoonotic potential, which demands the search for alternative methods of treatment. Treatment. Due to their antimicrobial properties, essential oils have potential for use in these cases. In this context, the objectives of this work were to determine the prevalence of otitis in a canine population of a collective shelter, identifying the agents involved in the etiology of the cases and to evaluate in vitro their susceptibility to conventional antibiotics through the disc diffusion test and to essential oils of Lemongrass, Clove of India, Cinnamon Cassia, Thyme and Melaleuca , through the broth microdilution test to determine the minimum inhibitory concentration. The study showed a high prevalence of canine otitis in shelter animals ( 90.83 %), WITH Malassezia being the main microorganisms identified. spp . (90.32%) , followed by Otodectes cynotis ( 33.87 % ), Staphylococcus positive coagulase (SCP) (24.19%) , FROM WHICH THE Staphylococcus species was identified pseudintermedius , Staphylococcus aureus and other SCP, and Staphylococcus Negative Coagulase (SCN) (14.52%). Susceptibility tests to conventional antibiotics showed high rates of resistance (38.84%) and the existence of resistant multidrug isolates. Among the essential oils tested, Canela Cassia and Thyme showed the highest antimicrobial action, with MIC50 values of 3.47 μL /mL and 7.3 μL /mL , respectively. The other oils, although they showed antimicrobial action in vitro , showed higher values of MIC50. Higher levels of resistance were observed among SCPs than SCNs, both for antibiotics and essential oils. In general, our results showed high prevalence rates for otitis in the studied canine population, which highlights the need to adopt preventive measures. to mitigate the disease, and high rates of resistance among isolated bacterial agents, mainly Staphylococcus pseudintermedius and Staphylococcus coagulase negative, compared to conventional antimicrobials, a factor of great concern, since they are agents with zoonotic potential and that, therefore, can cause risks to public health. Cassia cinnamon and lemongrass essential oils showed good antimicrobial efficiency in in vitro tests , proving to be an alternative to be evaluated in vivo for the treatment of canine otitis.