Combined use of ivermectin, dimethyl sulfoxide, mineral oil and nematophagous fungi to control Rhabditis spp.

Rhabditis spp., is a nematode known to cause otitis externa, an infection difficult to control, in cattle reared within tropical regions. The objective of this study was to assess the combined use of ivermectin 1%, dimethyl sulfoxide 1% and mineral oil 100% containing nematophagous fungi of both Duddingtonia flagrans (AC001) and Monacrosporium thaumasium (NF34) species to control in vitro Rhabditis spp. Thus, 12 experimental groups were designed with eight replicates each: G1 (nematodes + AC001); G2 (nematodes + NF34); G3 (nematodes + ivermectin 1%/positive control); G4 (nematodes + dimethyl sulfoxide 1%/positive control); G5 (nematodes + mineral oil 100%/positive control); G6 (nematodes + AC001 + ivermectin 1%); G7 (nematodes + NF34 + ivermectin 1%); G8 (nematodes + AC001 + mineral oil 100%); G9 (nematodes + NF34 + mineral oil 100%); G10 (nematodes + AC001 + dimethyl sulfoxide 1%); G11 (nematode + NF34 + dimethyl sulfoxide 1%); G12 (nematode + distilled water/negative control). The results demonstrated that all experimentally treated groups differed statistically (p < 0.01) from the control group. In the present study, the use of dimethyl sulfoxide 1% and mineral oil 100% in conjunction with conidia fungi portrayed noteworthy outcomes, which represents a future premise for the combined use of nematophagous fungi within these vehicles in both controlling Rhabditis spp.

Diseño y evaluación de las propiedades antibacterianas de un prototipo de molde de audífono que incorpora cobre en su manufactura / Design and evaluation of antibacterial properties of a prototype of earmold with copper incorporated in the manufacture

Introducción: La otitis externa infecciosa es una consulta otorrinolaringológica frecuente en usuarios de audífonos. Las propiedades antibacterianas descritas del cobre, han motivado el desarrollo de aplicaciones clínicas de este metal. Objetivo: Evaluar la capacidad antibacteriana de moldes de audífonos manufacturados con polímeros sensible a luz UV, silicona y acrílico que incorporan cobre metálico, en un sistema experimental in vitro. Material y método: Se diseñaron moldes de audífonos con y sin cobre, que fueron inoculados con distintas concentraciones de microorganismos (S aureus y P aeruginosa), para luego determinar el porcentaje de adherencia bacteriana a distintos tiempos de contacto (4, 8 y12 horas). Resultados: Existió reducción significativa en la adhesión bacteriana a los moldes con cobre respecto a aquellos sin cobre, independiente del material, del tipo de microorganismo y del inóculo bacteriano. Discusión: La disminución en la adherencia bacteriana en los prototipos con cobre, puede atribuirse a su actividad inhibitoria sobre los microorganismos en función de su concentración y el tiempo de contacto, ejerciendo su efecto por difusión a través de los distintos materiales. Conclusión: Con estos resultados, se hace necesario el desarrollo de estudios clínicos enfocados en comprobar si el uso de audífonos con cobre disminuyen las otitis externas de origen infeccioso.

Introduction: External otitis of infectious etiology among hearing aid users is a common motive of otolaryngology consultation. Antibacterial properties described copper, they have motivated the development of clinical applications of this metal. Aim: Evaluate the antibacterial capacity of copper-based ear molds manufactured with different materials such UV sensitive polymers, silicone and acrylic incorporating metallic copper, in an experimental system in vitro. Material and method: Ear molds with and without copper, were inoculated with different concentrations of microorganisms (S aureus and P aeruginosa) and determine the percentage of bacterial adherence to different contact times (4-8 and 12 hours). Results: There was significant reduction in bacterial adhesion to copper molds than those without copper, independent of the material, the type of microorganism and the bacterial inoculum. Discussion: The decrease in bacterial adherence on prototypes with copper, can be attributed to inhibitory activity on microorganisms depending on their concentration and contact time, exerting its effect by diffusion through the various materials. Conclusion: With these results, is necessary the development of clinical studies focused on checking whether the use of hearing aids with copper decreases external otitis of infectious origin.

Malassezia pachydermatis: enzymes production in isalates from external ear canal of dogs with and without otitis

Pesquisou-se a possível relação entre a produção de enzimas e a patogenicidade de Malassezia pachydermatis. Foram estudadas 30 cepas de M. pachydermatis provenientes de cães: 15 isoladas de animais com otite externa e 15 isoladas de condutos auditivos de animais assintomáticos. As amostras, obtidas pela introdução de uma zaragatoa no conduto auditivo, após limpeza do pavilhão auricular com solução de álcool-éter, foram semeadas em ágar Sabouraud dextrose acrescido de cloranfenicol (100mg/l) e incubadas a 37 graus centígrados por até dias semanas. As colônias foram identificadas por meio de estudo macro e micromorfológico. As amostras isoladas foram investigadas quanto à produção das enzimas condroitina-sulfatase, hialuronidase, fosfolipase e proteinase. A maioria delas mostrou alta produção das quatro enzimas pesquisadas. A análise estatística não evidenciou diferenças na atividade enzimática entre as amostras testadas. M. pachydermatis, isolada como componente da microbiota sapróbia ou nos casos de otite externa, tem a capacidade de produzir as quatro enzimas. Provavelmente M. pachydermatis apresenta outros fatores de virulência que estejam mais relacionados ao parasitismo.

Malassezia pachydermatis: enzymes production in isalates from external ear canal of dogs with and without otitis / Malassezia pachydermatis: produção de enzimas por amostras isoladas do conduto auditivo externo de cães com e sem otite

The relationship between production of enzymes and pathogenicity of Malassezia pachydermatis strains was studied. Thirty strains of M. pachydermatis isolated from dogs were used: 15 originating from animals with external otitis and 15 obtained from ears of asymptomatic dogs. The samples, obtained by introduction of a sterile swab into the auditory canal after cleaning the auricle with alcohol-ether solution, were seeded onto Sabouraud dextrose agar with chloramphenicol (100mg/l) and were incubated at 37°C for up to two weeks. The colonies were identified according to their macro-and-micromorphology. All strains were investigated for the production of chondroitin-sulphatase, hyaluronidase, phospholipase and proteinase. Most of the strains showed a high production of the four enzymes. Statistical analysis did not show any differences in the enzymatic activity among the strains. M. pachydermatis originating in normal microbiota as well as in otic secretion from dogs with otitis could produce the four researched enzymes. Probably M. pachydermatis has other virulence factors that are involved in the parasitism.(AU)

Pesquisou-se a possível relação entre a produção de enzimas e a patogenicidade de Malassezia pachydermatis. Foram estudadas 30 cepas de M. pachydermatis provenientes de cães: 15 isoladas de animais com otite externa e 15 isoladas de condutos auditivos de animais assintomáticos. As amostras, obtidas pela introdução de uma zaragatoa no conduto auditivo, após limpeza do pavilhão auricular com solução de álcool-éter, foram semeadas em ágar Sabouraud dextrose acrescido de cloranfenicol (100mg/l) e incubadas a 37°C por até duas semanas. As colônias foram identificadas por meio de estudo macro e micromorfológico. As amostras isoladas foram investigadas quanto à produção das enzimas condroitina-sulfatase, hialuronidase, fosfolipase e proteinase. A maioria delas mostrou alta produção das quatro enzimas pesquisadas. A análise estatística não evidenciou diferenças na atividade enzimática entre as amostras testadas. M. pachydermatis, isolada como componente da microbiota sapróbia ou nos casos de otite externa, tem a capacidade de produzir as quatro enzimas. Provavelmente M. pachydermatis apresenta outros fatores de virulência que estejam mais relacionados ao parasitismo.(AU)

Otitis in cattle, an aetiological review.

Otitis externa in cattle has a significant impact in tropical and subtropical regions, and the aetiological agents are predominantly rhabditiform nematodes and mites of the genus Raillietia. Its prevalence is higher in mature and Zebu cattle. In advanced clinical cases there can be irreversible and fatal neural lesions. Ear infection in calves has been associated with concurrent respiratory diseases and mixed infection. The principal reported agents of otitis in calves are bacteria such as Actinomyces spp., Corynebacterium pseudotuberculosis, Escherichia coli, Haemophilus somnus, Pasteurella multocida, Mannheimia haemolytica, Pseudomonas spp., Streptococcus spp. and Mycoplasma bovis. The control and treatment of bovine otitis is not standardized and there is little evidence-based support for the diverse treatments available in the literature.