Concordance between otic cytology and culture in diagnosis of external otitis canine by Malassezia spp

ABSTRACT Objective. To determine the correlation between microbiological culture and otic cytology for diagnoses of external otitis by Malassezia in dogs. Materials and methods. 158 ear swabs of dogs with clinical diagnosis of external otitis were analyzed by cytology, mycological culture and metabolic tests. Results. Were obtained a positive results by cytology of 62% and 75.3% by culture. The 31.1% of isolates were identified as M. pachydermatis, 12.6% as M. furfur and 56.3% were classified as Malassezia spp., because was not possible to define the species. We found a positive concordance between cytology and culture for Malassezia spp., of 0.76 with a kappa index of 0.448 (95% CI 0.30 to 0.60) which represents a moderate strength of concordance between the two techniques, without regard the identified species. Conclusions. The use of a diagnostic test is not enough to establish the participation of Malassezia spp., as a causal disease agent

Efecto de la N-Acetilcisteína como coadyuvante en el tratamiento de otitis externa por Malassezia spp en perros

La N-Acetilcisteína es un compuesto utilizado en la clínica diaria para tratar patologías de las vías respiratorias bajas, úlceras corneales, infecciones del tracto urinario e intoxicaciones por acetaminofén. Sin embargo, se ha observado en diferentes estudios su eficacia en el tratamiento de otitis externa como coadyuvante, debido a su acción antimicrobiana, mucolítica y antioxidante. La otitis externa en la especie canina es una patología encontrada con frecuencia, cuyo porcentaje ronda el 20% y del cual el 50% de los casos suelen ser crónicos siendo la Malassezia spp un patógeno involucrado en esta enfermedad. El presente estudio tuvo como objeto evaluar el efecto de la N-Acetilcisteína como coadyuvante en el tratamiento de otitis externa causada por Malassezia spp en perros, en la clínica de especialidades “VetPro” de la ciudad de Cuenca, Ecuador. Se clasificó la otitis mediante la escala OTIS-3 y se realizaron hisopados y citologías a 20 perros con tratamiento control y a 20 perros con N-Acetilcisteína al día 0, 5 y 20 para valorar la carga de Malassezia spp y se determinó al paciente como recuperado o no recuperado. Al evaluarse por la escala OTIS-3 demostró que al día 20 el parámetro secreción disminuyó significativamente (p = 0,018) al tratamiento con N-Acetilcisteína en el conducto auditivo vertical y resultados similares en conducto auditivo horizontal (p = 0,058). El conteo de Malassezia spp al final del estudio no demostró diferencias significativas en el grupo Tratamiento con N-Acetilcisteína en referencia al grupo Control (p > 0,05). En la recuperación basada en OTIS-3 el grupo tratado con NAcetilcisteína al día 20 con respecto al día 0, reveló diferencia significativa (p = 0,031). Los resultados demuestran que la N-Acetilcisteína cumple una función antibiofilm pues disminuye la cantidad de secreción.N-Acetylcysteine is a compound used in the daily clinic to treat pathologies of the lower respiratory tract, corneal ulcers, urinary tract infections and acetaminophen poisoning. However, its efficacy in the treatment of external otitis as an adjuvant has been observed in different studies, due to its antimicrobial, mucolytic and antioxidant action. Otitis externa in the canine species is a pathology frequently found in patients, whose percentage is around 20% and of which 50% of cases are usually chronic, with Malassezia spp being a pathogen involve in this disease. The aim of this study was to assess the effect of N-Acetylcysteine as an adjuvant in the treatment of external otitis caused by Malassezia spp in dogs, at the “VetPro” specialty clinic in the city of Cuenca, Ecuador. Otitis was classified using the OTIS-3 scale and swabs and cytologies were performed on 20 dogs with control treatment and 20 dogs with N-Acetylcysteine at day 0, 5 and 20 to assess the load of Malassezia spp and the patient was determined as recovered or not recovered. When evaluated by the OTIS-3 scale, it was shown that on day 20 the secretion parameter decreased significantly (p = 0.018) when treated with N-Acetylcysteine in vertical ear canal and similar results in horizontal ear canal (p = 0.058). The Malassezia spp count at the end of the study did not show significant differences in the Treatment group with N- Acetylcysteine compared to the Control group (p > 0.05). In the recovery based on OTIS-3, the group treated with NAcetylcysteine at day 20 compared to day 0, revealed a significant difference (p = 0.031). The results show that N-Acetylcysteine fulfills an antibiofilm function since it decreases the amount of secretion and the recovery of patients at the end of treatment is evident.Médico Veterinario ZootecnistaCuenc

Concordance between otic cytology and culture in diagnosis of external otitis canine by Malassezia spp

Objective. To determine the correlation between microbiological culture and otic cytology for diagnoses of external otitis by Malassezia in dogs. Materials and Methods. 158 ear swabs of dogs with clinical diagnosis of external otitis were analyzed by cytology, mycological culture and metabolic tests. Results. Were obtained a positive results by cytology of 62% and 75.3% by culture. The 31.1% of isolates were identified as M. pachydermatis, 12.6% as M. furfur and 56.3% were classified as Malassezia spp., because was not possible to define the species. We found a positive concordance between cytology and culture for Malassezia spp., of 0.76 with a kappa index of 0.448 (95% CI 0.30 to 0.60) which represents a moderate strength of concordance between the two techniques, without regard the identified species. Conclusions. The use of a diagnostic test is not enough to establish the participation of Malassezia spp., as a causal disease agent.Objetivo. Determinar la concordancia entre el cultivo microbiológico y la citología ótica para el diagnóstico de otitis externa causada por Malassezia spp. en caninos. Materiales y Métodos. Se analizaron 158 muestras de hisopados de caninos con diagnóstico clínico de otitis externa, todas las muestras fueron analizadas mediante citología, cultivo micológico y pruebas metabólicas. Resultados. Se obtuvo una positividad mediante citología del 62% y por cultivo del 75.3%. El 31.1% de los aislamientos fueron identificados como M. pachydermatis, el 12.6% como M. furfur y un 56.3% se clasificó como Malassezia spp., dado que bioquímicamente no fue posible hallar su especie. Se determinó una concordancia observada entre técnicas positivas para Malassezia spp. de 0.76 con índice Kappa de 0.448 IC 95% (0.30 - 0.60) lo que representa una fuerza de concordancia moderada entre las dos técnicas, sin tener en cuenta la especie identificada. Conclusiones. El uso de una prueba diagnóstica no es suficiente para establecer la participación de Malassezia pachydermatis como agente causal de enfermedad