Antimicrobial and antibiofilm effect of promethazine on bacterial isolates from canine otitis externa: an in vitro study.

Otitis externa is an inflammatory disease of the external ear canal of complex and multifactorial etiology associated with recurrent bacterial infection. This study aimed to assess the antimicrobial and antibiofilm activity of promethazine against bacterial isolates from dogs with otitis externa, as well as the effect of this compound on the dynamics of biofilm formation over 120 h. Planktonic bacterial susceptibility to promethazine was evaluated to determine the minimum inhibitory concentrations (MIC). The minimum biofilm eradication concentration (MBEC) was also determined by broth microdilution. To evaluate the effect on biofilm growth, promethazine was tested at three concentrations MIC, MIC/2 and MIC/8, with daily readings at 48, 72, 96 and 120 h. The MICs of promethazine ranged from 48.83 to 781.25 µg mL-1. Promethazine significantly (P < 0.05) reduced mature biofilm biomass, with MBECs ranging from 48.8 to 6250 µg mL-1 and reduced (P < 0.01) biofilm formation for up to the 120-h, at concentrations corresponding to the MIC obtained against each isolate. Promethazine was effective against microorganisms associated with canine otitis externa. The data suggest that promethazine presents antimicrobial and antibiofilm activity and is a potential alternative to treat and prevent recurrent bacterial otitis in dogs. These results emphasize the importance of drug repurposing in veterinary otology as an alternative to reduce antimicrobial resistance.

Prevalence and clinical findings of feline otitis externa in Midwest Brazil.

This study was conducted to evaluate the prevalence of otitis externa (OE) in cats using cytology, direct otoscopic examination, and parasitological examination through swabs and curettage, and to compare the accuracy between collection methods for parasitological examination. Direct otoscopic evaluation of the external auditory canal (right and left), swabs for cytological examination of the external auditory canal, and collection of cerumen for parasitological examination through swabs and curettage of 137 cats from a veterinary hospital care were conducted between March 2021 and March 2022. The influences of age, sex, habitat, street access, and the presence of fleas on OE were evaluated. Cytological evidence of OE was observed in 25.5 % of cats and was statistically associated with flea and mite parasitism. Otodectes cynotis was found in 13.9 % of the cats. Cocci and Bacilli were the secondary factors in 34.3 % and 22.9 % of cats with OE, respectively. The Malassezia genus was a secundary factor in 57.1 % of the cats with OE. The frequency of OE was high in cats receiving hospital care. O. cynotis was a frequent primary cause of OE in cats. The curette sampling method is a great option for diagnosing O. cynotis infestation due to its ease of use.

Identification of bacteria associated with canine otitis externa based on 16S rDNA high-throughput sequencing.

Bacteria are regarded as predisposing and perpetuating factors causing otitis externa (OE), whereas auricular anatomy is a predisposing factor. This study aims to investigate bacterial populations in the external auditory canals of healthy dogs and dogs with OE. Four categories of ear swabs included healthy erect-ear dogs, erect-ear dogs with OE, healthy pendulous-ear dogs and pendulous-ear dogs with OE. After bacterial DNA extraction, 16S rDNAs were amplified using specific primers within a V3/V4 region. Following DNA library construction, high-throughput sequencing was performed on MiSeq (Illumina). CLC Microbial Genomics Module was used to determine the rarefaction curve, bacterial classification, relative abundance, richness and diversity index. The results demonstrated that healthy dogs had higher bacterial richness and diversity than the dogs with OE. Comparable with culture-dependent methods described previously, this study revealed predominant Corynebacterium spp., Pseudomonas spp., Staphylococcus spp., and Proteus spp. in OE cases. Furthermore, high-throughput sequencing might disclose some potential emerging pathogens including Tissierella spp., Acinetobacter spp., and Achromobacter spp., which have not been reported in previous canine OE cases. Nevertheless, larger sample sizes are further required for an extensive evidence-based investigation.

Predictive value of radiologic studies for malignant otitis externa: a systematic review and meta-analysis.

OBJECTIVE: To determine the diagnostic accuracy of Necrotizing Otitis Externa (NOE) based on radiologic studies. METHODS: The PubMed, Cochrane, Embase, Web of Science, SCOPUS, and Google Scholar databases were searched. True-positive and false-negative results were extracted for each study. Methodological quality was evaluated using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. RESULTS: The included studies contained data on 37 studies diagnosed with NOE. The sensitivity of gallium-67, technetium-99m, and Magnetic Resonance Imaging (MRI) was 0.9378 (0.7688-0.9856), 0.9699 (0.8839-0.9927), and 0.9417 (0.6968-0.9913), respectively. For Computed Tomography (CT), the positive criteria consisted of bony erosion alone and bony erosion plus any soft tissue abnormality. The sensitivity of CT based only on bony erosion was 0.7062 (0.5954-0.7971); it was higher 0.9572 (0.9000-0.9823) when based on bony erosion plus any soft tissue abnormality. CONCLUSION: The diagnostic sensitivity of technetium-99m, gallium-67, and MRI was favorable. On CT, the presence of bony erosion may be a useful diagnostic marker of NOE, but the diagnostic sensitivity will be even higher if the criterion of any soft tissue abnormality is also included; however, care should be taken when interpreting the results. Our study demonstrates the potential utility of radiology studies for diagnosing NOE, but their lack of specificity must be considered, and standardized anatomic criteria are still needed. LEVEL OF EVIDENCE: 2A.

Clinical and epidemiological features and impact of life habits in canine atopic dermatitis in Fortaleza, Brazil / Achados clínicos e epidemiológicos e impacto do estilo de vida na dermatite atópica canina em Fortaleza/Brasil

Canine atopic dermatitis (cAD) is a worldwide allergic skin disease. The affected dog population can show different clinical patterns according to geographic region, and a lack of studies in Brazil is observed. Therefore, the aim of the present study was to assess the clinical and epidemiological data of cAD in dogs treated in a private clinical practice in Fortaleza, a city located in the Northeast Region of Brazil. cAD was diagnosed in 35% of dogs, being Shih-tzu and Poodle the most affected breeds. Paws and ears were frequently injured sites. Almost 50% of atopic dogs were diagnosed with superficial pyoderma and 36% with cutaneous malasseziosis. Atopic dogs with outdoor habits were less likely to develop cutaneous malassezial infection, and with routine ear, cleaning habits were less likely to develop bacterial otitis externa. In conclusion, canine atopic dermatitis is a prevalent disease in private clinical practice in Fortaleza, and lifestyle habits can be considered a risk factor for cutaneous malasseziosis infection and bacterial otitis externa in atopic dogs.

A dermatite atópica canina (DAC) é uma doença alérgica cutânea de ocorrência mundial. A população canina acometida pode apresentar diferentes padrões clínicos de acordo com a região geográfica e observa-se uma carência de estudos no Brasil. Portanto, o objetivo do presente estudo é avaliar os dados clínicos e epidemiológicos da DAC em cães atendidos em uma clínica privada em Fortaleza, cidade localizada na Região Nordeste do Brasil. A DAC foi diagnosticada em 35% dos cães, sendo Shih-tzu e Poodle as raças mais acometidas. As patas e as orelhas foram locais frequentemente afetados. Quase 50% dos cães atópicos foram diagnosticados com piodermite superficial e 36% com malasseziose cutânea. Cães atópicos com hábitos ao ar livre foram menos propensos a desenvolver malasseziose cutânea e com hábitos rotineiros de limpeza auricular foram menos propensos a desenvolver otite externa bacteriana. Em conclusão, a dermatite atópica canina é uma doença prevalente na prática clínica privada em Fortaleza e os hábitos de vida podem ser considerados como um fator de risco para infecção por malasseziose cutânea e otite externa bacteriana em cães atópicos.

Homeopathy treatment of Malassezia Pachydermatis in vitro

A common clinical occurrence in dogs is otitis externa caused by excessive growth of yeasts Malassezia pachydermatis, which can become chronic after wrong treatments, in which microbial resistance can occur. Homeopathic remedies can be considered a successful alternative, selecting the medicine through the similitude principle. Herein, 50 µL of a 1:1000 dilution of Malassezia pachydermatis suspension at 0.5 McFarland scale was used to seed the yeast into Sabouraud dextrose agar plates using a Drigalski spreader to proceed with colony unit counting. Before being seeded, the yeast suspensions were treated with 1% of different homeopathic treatments previously selected from a pilot study, which means Sulphur 6cH, Dolichos pruriens 6cH, and Kali carbonicum 6cH, being water, and succussed water used as controls. For comparison, a set of Sabouraud dextrose agar plates containing 1% Tween 80 was seeded in parallel. The treatments were made blind and evaluated in triplicate. Contaminated cultures were withdrawn. The number of colonies per plate was assessed, and smears were made from the cultures to classify yeast growth according to cytomorphology on ImageJ®software. The preliminary results show no significant effect of all tested medicines compared to the controls. High data variability was also observed, mainly in those cultures whose medium was prepared with Twin 80. In conclusion, at this point of the study, no evidence of the effects of the studied medicines on Malassezia pachydermatis growth in vitro could be identified. The analysis of cytomorphology is still in course.

Profile of otitis externa isolates in dogs and cats diagnosed in laboratory of microbiology in 2020 / Perfil dos isolados de otites externas em cães e gatos diagnosticados em laboratório de microbiologia em 2020

Otitis externa is one of the most frequent diseases in the clinical routine of dogs and cats, and they can be caused by several associated factors. Due to incorrect use of antimicrobial products, the treatment and control of otitis have become challenging. This study aims to analyze the results of otological exams at the Laboratory of Microbiology HV-ULBRA in 2020 and demonstrate the profile of patients and isolated bacteria. Staphylococcus was the main genus isolated, and 71,11% of samples showed multi-drug resistance to antimicrobial testing. These results indicate the need to use complementary examinations to control otitis externa.(AU)

A otite externa é um das enfermidades mais frequentes na rotina clínica de cães e gatos e pode ser causada por diversos fatores associados. Devido ao uso incorreto de antimicrobianos, o tratamento e o controle das otites se tornaram desafiadores. O objetivo desse estudo é analisar os resultados dos exames otológicos encaminhados ao Laboratório de Microbiologia HV-ULBRA em 2020 e, além disso, delinear o perfil dos pacientes e das bactérias isoladas. Staphylococcus foi o principal gênero isolado e 71,11% das amostras apresentou multirresistência aos antimicrobianos testados. Esses resultados evidenciam a necessidade do uso de exames complementares para controle das otites externas.(AU)

Antifungal susceptibility of Malassezia pachydermatis isolated from the external auditive conduct from dogs, in central Chile.

Background: External otitis is common in dogs, and one of the main agents involved is Malassezia pachydermatis, a yeast belonging to the otic microbiota. Empirical treatment can fail; therefore, it is essential to know the antifungal susceptibility profile to prescribe appropriate treatment, a fact scarcely reported in Chile. Aim: This study aimed to determine the antifungal sensitivity of M. pachydermatis isolated from the external auditory canal of dogs in central Chile. Methods: Ear swabs from 30 dogs (15 healthy and 15 with external otitis) were used. Samples were subjected to cytology and fungal culture. The antifungal susceptibility was determined according to clinical and laboratory standards institute (CLSI) document M44A-2 using the disk diffusion test from amphotericin B, Caspofungin, fluconazole, nystatin, clotrimazole, and voriconazole were used. Results: The prevalence of M. pachydermatis was 66.7% from 8 healthy dogs and 12 with otitis. While fungal culture was not associated with the patient's clinical condition (p = 0.24), the yeast count by cytology was significantly higher in dogs with otitis (p = 0.003). The strains were sensitive to all antifungals except for Caspofungin, where 55% of the strains were resistant. Conclusion: Malassezia pachydermatis is isolated more frequently in dogs with otitis, and the ear cytological examination is useful to differentiate colonized dogs versus dogs with otitis. In addition, most antifungals in vitro are active against this yeast, except Caspofungin, an antifungal used in human medicine. This situation should be further monitored in epidemiological programs to evaluate the possible impact on Chilean public health.

High rates of multidrug resistance in bacteria associated with small animal otitis: A study of cumulative microbiological culture and antimicrobial susceptibility.

The etiology of otitis in dogs and cats is multifactorial and complex, involving bacterial and fungal pathogens. As empiric antimicrobial prescription is a common practice when treating such cases, antimicrobial resistance may represent a complicating factor. The aim of this study was to describe microbiological features and susceptibility profiles of pathogens associated with 142 cases of external otitis, comprising 138 dogs and 4 cats.. The specimens were processed to identify bacterial and fungal etiologies following standard microbiological methods. Antimicrobial susceptibility was determined in vitro against 15 antibiotics and 3 antifungals. Further, Staphylococcus spp. isolates were screened for the detection of ß-lactamase enzymes using cefinase paper discs. Pseudomonas spp. and isolates from Enterobacteriaceae family were screened for colistin (Polymyxin E) resistance and for the mcr-1-mediated colistin resistance gene by PCR. The presence of mixed cultures of Enterobacteriaceae, Pseudomonas spp. and Staphylococcus spp., and co-infections with Malassezia spp., emphasizes the polymicrobial etiology of external otitis in small animals. Emerging rates of multidrug resistance observed in almost 50% of the isolates may alert for a near future of challenging veterinary cases unresponsive to first-line antimicrobials. In addition, these results highlight a potential public health concern of multidrug resistant bacteria, given the proximity of pets and their owners. This study addressed central aspects of external otitis, providing microbiologists and clinicians updated information on the etiology and treatment of challenging cases of multidrug resistant bacteria. It also provides priceless surveillance value in monitoring resistant bacteria in small animals.

Etiologia microbiana e perfil de resistência bacteriana in vitro em otites externas de cães: estudo retrospectivo em animais atendidos na rotina de hospital veterinário (2013 a 2020) / Microbial etiology and in vitro bacterial resistance profile in external dogs otitis: retrospective study in animals attended in the routine of veterinary hospital (2013 to 2020) / Etiología microbiana y perfil de resistencia bacteriana in vitro en otitis externa en perros: estudio retrospectivo en animales atendidos en la rutina de hospital veterinario (2013 a 2020)

El objetivo de este estudio fue identificar la microbiota y describir el perfil de sensibilidad de las bacterias a los antimicrobianos en perros con otitis externa tratados en un hospital veterinario. Para ello, se analizaron 559 muestras otológicas de perros con clínica de otitis externa sometidas a cultivo y antibiograma. Hubo crecimiento de microorganismos en el 93,6% (523/559) de las muestras, y en el 88,5% (463/523) hubo crecimiento de bacterias, 5,7% (30/523) de levaduras y 5,7% (30/523) infecciones mixtas. Se obtuvieron 702 cepas, Staphylococcus spp. 55,1% (387/702), Pseudomonas spp. 11,8% (83/702) y Proteus mirabilis 9,8% (69/702) los agentes bacterianos más aislados. Entre las levaduras, Malassezia pachydermatis 10,3% (54/523) fue la más frecuente. En cuanto a los resultados del perfil de sensibilidad de las bacterias a los antimicrobianos, se observó que las bacterias Gram positivas Staphylococcus spp. y Streptococcus spp. mostraron mayor sensibilidad a amoxicilina + ácido clavulánico, con 92,5% y 100% de cepas sensibles. Las bacterias gram negativas Pseudomonas spp., P. mirabilis y Escherichia coli, presentaron sensibilidad mayor al 90% a la tobramicina. Entre todos los agentes bacterianos, Pseudomonas spp. fue el que mostró mayores tasas de resistencia frente a amoxicilina + ácido clavulánico (6,2%), cefalexina (7,4%) y sulfametoxazol + trimetoprima (13,6%)...(AU)

The objective of this work was to identify the microbial etiology and describe the sensitivity profile of bacteria to antimicrobials in dogs with otitis externa attended at a veterinary school hospital. For this, 559 otological samples from dogs with clinical signs of otitis externa submitted to culture and antibiogram were analyzed. There was growth of microorganisms in 93.6% (523/559) of the samples, and in 88.5% (463/523) there was the growth of bacteria, in 5.7% (30/523) the growth of yeasts and 5.7% (30/523) mixed infections. 702 strains were obtained, being Staphylococcus spp. 55.1% (387/702), Pseudomonas spp. 11.8% (83/702) and Proteus mirabilis 9.8% (69/702) the most isolated bacterial agents. Among yeasts, Malassezia pachydermatis 10.3% (54/523) was the most frequent. Regarding the results of the sensitivity profile of bacteria to antimicrobials, it was observed that Gram-positive bacteria Staphylococcus spp. and Streptococcus spp. showed greater sensitivity to amoxicillin + clavulanic acid, with 92.5% and 100% of sensitive strains. Gram-negative bacteria Pseudomonas spp., P. mirabilis and Escherichia coli, presented sensitivity greater than 90% to tobramycin. Among all bacterial agents, Pseudomonas spp. was the one that demonstrated the highest resistance rates against amoxicillin + clavulanic acid (6.2%), cephalexin (7.4%) and sulfamethoxazole + trimethoprim (13.6%)...(AU)

O objetivo deste trabalho foi identificar a etiologia microbiana e descrever o perfil de sensibilidade das bactérias aos antimicrobianos em cães com otite externa atendidos em serviço hospitalar médico veterinário. Para isso, foram analisadas 559 amostras otológicas de cães com sinais clínicos de otite externa submetidas à cultura e antibiograma. Houve crescimento de microrganismos em 93,6% (523/559) das amostras, sendo que em 88,5% (463/523) houve crescimento de bactérias, 5,7% (30/523) crescimento de leveduras e 5,7% (30/523) infecções mistas. Foram obtidas 702 cepas, sendo Staphylococcus spp. 55,1% (387/702), Pseudomonas spp. 11,8% (83/702) e Proteus mirabilis 9,8% (69/702) os agentes bacterianos mais isolados. Dentre as leveduras, Malassezia pachydermatis 10,3% (54/523) foi a mais freqüente. Em relação aos resultados do perfil de sensibilidade das bactérias aos antimicrobianos, observou-se que as bactérias Gram-positivas Staphylococcus spp. e Streptococcus spp. apresentaram maior sensibilidade a amoxicilina + ácido clavulânico, com 92,5% e 100% das cepas sensíveis. Já as bactérias Gram-negativas Pseudomonas spp., P. mirabilis e Escherichia coli, apresentaram sensibilidade superior a 90% a tobramicina. Dentre todos os agentes bacterianos, Pseudomonas spp. foi o que demonstrou as maiores taxas de resistência frente a amoxicilina + ácido clavulânico (6,2%), cefalexina (7,4%) e...(AU)

Etiologia microbiana e perfil de resistência bacteriana in vitro em otites externas de cães: estudo retrospectivo em animais atendidos na rotina de hospital veterinário (2013 a 2020) / Microbial etiology and in vitro bacterial resistance profile in external dogs otitis: retrospective study in animals attended in the routine of veterinary hospital (2013 to 2020) / Etiología microbiana y perfil de resistencia bacteriana in vitro en otitis externa en perros: estudio retrospectivo en animales atendidos en la rutina de hospital veterinario (2013 a 2020)

El objetivo de este estudio fue identificar la microbiota y describir el perfil de sensibilidad de las bacterias a los antimicrobianos en perros con otitis externa tratados en un hospital veterinario. Para ello, se analizaron 559 muestras otológicas de perros con clínica de otitis externa sometidas a cultivo y antibiograma. Hubo crecimiento de microorganismos en el 93,6% (523/559) de las muestras, y en el 88,5% (463/523) hubo crecimiento de bacterias, 5,7% (30/523) de levaduras y 5,7% (30/523) infecciones mixtas. Se obtuvieron 702 cepas, Staphylococcus spp. 55,1% (387/702), Pseudomonas spp. 11,8% (83/702) y Proteus mirabilis 9,8% (69/702) los agentes bacterianos más aislados. Entre las levaduras, Malassezia pachydermatis 10,3% (54/523) fue la más frecuente. En cuanto a los resultados del perfil de sensibilidad de las bacterias a los antimicrobianos, se observó que las bacterias Gram positivas Staphylococcus spp. y Streptococcus spp. mostraron mayor sensibilidad a amoxicilina + ácido clavulánico, con 92,5% y 100% de cepas sensibles. Las bacterias gram negativas Pseudomonas spp., P. mirabilis y Escherichia coli, presentaron sensibilidad mayor al 90% a la tobramicina. Entre todos los agentes bacterianos, Pseudomonas spp. fue el que mostró mayores tasas de resistencia frente a amoxicilina + ácido clavulánico (6,2%), cefalexina (7,4%) y sulfametoxazol + trimetoprima (13,6%)...

The objective of this work was to identify the microbial etiology and describe the sensitivity profile of bacteria to antimicrobials in dogs with otitis externa attended at a veterinary school hospital. For this, 559 otological samples from dogs with clinical signs of otitis externa submitted to culture and antibiogram were analyzed. There was growth of microorganisms in 93.6% (523/559) of the samples, and in 88.5% (463/523) there was the growth of bacteria, in 5.7% (30/523) the growth of yeasts and 5.7% (30/523) mixed infections. 702 strains were obtained, being Staphylococcus spp. 55.1% (387/702), Pseudomonas spp. 11.8% (83/702) and Proteus mirabilis 9.8% (69/702) the most isolated bacterial agents. Among yeasts, Malassezia pachydermatis 10.3% (54/523) was the most frequent. Regarding the results of the sensitivity profile of bacteria to antimicrobials, it was observed that Gram-positive bacteria Staphylococcus spp. and Streptococcus spp. showed greater sensitivity to amoxicillin + clavulanic acid, with 92.5% and 100% of sensitive strains. Gram-negative bacteria Pseudomonas spp., P. mirabilis and Escherichia coli, presented sensitivity greater than 90% to tobramycin. Among all bacterial agents, Pseudomonas spp. was the one that demonstrated the highest resistance rates against amoxicillin + clavulanic acid (6.2%), cephalexin (7.4%) and sulfamethoxazole + trimethoprim (13.6%)...

O objetivo deste trabalho foi identificar a etiologia microbiana e descrever o perfil de sensibilidade das bactérias aos antimicrobianos em cães com otite externa atendidos em serviço hospitalar médico veterinário. Para isso, foram analisadas 559 amostras otológicas de cães com sinais clínicos de otite externa submetidas à cultura e antibiograma. Houve crescimento de microrganismos em 93,6% (523/559) das amostras, sendo que em 88,5% (463/523) houve crescimento de bactérias, 5,7% (30/523) crescimento de leveduras e 5,7% (30/523) infecções mistas. Foram obtidas 702 cepas, sendo Staphylococcus spp. 55,1% (387/702), Pseudomonas spp. 11,8% (83/702) e Proteus mirabilis 9,8% (69/702) os agentes bacterianos mais isolados. Dentre as leveduras, Malassezia pachydermatis 10,3% (54/523) foi a mais freqüente. Em relação aos resultados do perfil de sensibilidade das bactérias aos antimicrobianos, observou-se que as bactérias Gram-positivas Staphylococcus spp. e Streptococcus spp. apresentaram maior sensibilidade a amoxicilina + ácido clavulânico, com 92,5% e 100% das cepas sensíveis. Já as bactérias Gram-negativas Pseudomonas spp., P. mirabilis e Escherichia coli, apresentaram sensibilidade superior a 90% a tobramicina. Dentre todos os agentes bacterianos, Pseudomonas spp. foi o que demonstrou as maiores taxas de resistência frente a amoxicilina + ácido clavulânico (6,2%), cefalexina (7,4%) e...

Minimum inhibitory concentration of essential oils against Staphylococcus aureus isolated from dogs with external otitis / Concentração inibitória mínima de óleos essenciais contra Staphylococcus aureus isolados de cães com otite externa

Canine otitis externa is a disease that affects the external acoustic meatus of about 20% of dogs at some point in life, without predilection for race, age, or sex. It is a multifactorial disease whose etiology involves several microorganisms, detaching Staphylococcus aureus. Antimicrobials are the basis for treating this illness; however, due to the increase in antimicrobial resistance, conventional drugs have become ineffective, requiring the search for alternative therapies. In this context, essential oils (EOs) have great therapeutic potential due to their broad antimicrobial action. This study aimed to evaluate the minimum inhibitory concentration (MIC) in order to measure the MIC50 and MIC90 of gentamicin and EOs of Eugenia caryophyllata, Thymus vulgaris, Cymbopogon winterianus, Cymbopogon citratus, and Cinnamomum cassia against 62 Staphylococcus aureus strains isolated from the external acoustic meatus of dogs. All EOs showed antibacterial action against the studied microorganisms, and their MIC50 and MIC90 were as follows: Eugenia caryophyllata, 2.42 mg mL-1 and 7.25 mg mL-1; Thymus vulgaris, 9.51 mg mL-1 and 22.94 mg mL-1; Cymbopogon winterianus, 26.78 mg mL-1 and 157.79 mg mL-1; Cinnamomum cassia and Cymbopogon citratus, lower than 16.48 and 27.81 mg mL-1, with the same MIC for all isolates. The MIC50 and MIC90 found for gentamicin were 1µg mL-1 and 8 µg mL-1. The MIC range found to antibiotic in this assay was 0.5 µg mL-1 to 128 µg mL-1, and the isolates were classified as susceptible [48 strains (77.41%) - MIC range of 0.5-4.0 µg mL-1], intermediate [eight strains (12.90%) - (MIC = 8.0 µg mL-1], or resistant [six strains (9.68%) - MIC ≥ 16 µg mL-1]. The results, according to the in vitro assays, showed that resistance to gentamicin, one of the antimicrobials most commonly used to treat canine otitis, is present in the Staphylococcus aureus population evaluated. Additionally, the tested EOs have great potential for therapeutic use, however future studies should be carried out to evaluate their in vivo efficacy.(AU)

A otite canina externa é uma doença que afeta o meato acústico externo de até 20% dos cães em algum período de suas vidas, sem predileção por raça, idade ou sexo. Trata-se de uma doença multifatorial que tem Staphylococcus aureus como um dos principais agentes etiológicos. Antimicrobianos constituem a base para o tratamento desta enfermidade, entretanto, devido ao incremento da resistência antimicrobiana, os fármacos convencionais tem se tornado pouco eficazes, o que requer a busca por terapias alternativas. Neste contexto, os óleos essenciais (OE) apresentam grande potencial terapêutico devido a sua ampla ação antimicrobiana. Este trabalho visou detectar a concentração inibitória mínima (CIM), a partir da qual foram obtidos os índices de MIC50 e MIC90 para a gentamicina e para os OE de Eugenia caryophyllata, Thymus vulgaris, Cymbopogon winterianus, Cymbopogon citratus e Cinnamomum cassia contra 62 Staphylococcus aureus isolados do meato acústico externo de cães otopatas. Todos os OE mostraram ação antibacteriana contra os microrganismos estudados e foram detectadas as seguintes CIM50 e CIM90: Eugenia caryophyllata, 2,42 mg mL-1 e 7,45 mg mL-1; Thymus vulgaris, 9,51 mg mL-1 e 22,94 mg mL-1; Cymbopogon winterianus, 26,78 mg mL-1 e 157,79 mg mL-1; Cinnamomum cassia e Cymbopogon citratus com CIM menores que 16,48 e 27,81 mg mL-1, respectivamente já que estes apresentaram CIM única para todos os isolados testados. Para a gentamicina, foram obtidas CIM50 e CIM90 1µg mL-1 e 8 µg/m, respectivamente. Ademais, a faixa de CIM encontrada para o antibiótico variou de 0,5 a 128 µg mL-1, e os isolados foram classificados em susceptíveis [48 isolados (77,41%) - CIM na faixa de 0,5-4 µg mL-1], intermediários [8 isolados (12,90%) - (CIM = 8µg mL-1] e resistentes [6 isolados (9,68%) - CIM ≥16]. Os resultados encontrados mostraram que os micro-organismos testados tem potencial para desenvolver resistência antimicrobiana a terapêutica tradicional e que os OE, de acordo com os resultados in vitro, apresentam potencial de uso terapêutico, entretanto futuros estudos devem ser realizados para avaliar a eficácia dos OE in vivo.(AU)

Mycotic aortic aneurysm in a debilitated patient with compromised immunity; beware of Candida! / Aneurisma micótico da aorta em paciente debilitado com imunidade comprometida - um alerta para Cândida

Abstract Candida is a rare cause of infected aortic aneurysms. We report the case of a diabetic patient with end stage kidney disease who underwent repair of a leaking abdominal aortic aneurysm. He was on long-term antibiotic treatment for malignant otitis externa. Candida albicans was isolated from the culture of the excised aneurysm wall. An infected aortic aneurysm due to Candida has not been previously reported in a patient with malignant otitis externa. This case report aims to highlight that Candida should be suspected as a cause of infected aortic aneurysms in patients with debilitation and chronic immunosuppression. Management of such cases can be extremely challenging, especially in resource-poor settings, and we will be touching upon the advantages and disadvantages of various treatment options.

Resumo A cândida é uma causa rara de aneurismas da aorta infecciosos. Relatamos o caso de um paciente diabético com doença renal terminal, que foi submetido a reparo de aneurisma da aorta abdominal com vazamento. Ele estava em tratamento de longo prazo com antibióticos para otite externa maligna. A Candida albicans foi isolada da cultura da parede do aneurisma que sofreu a excisão. Não há relatos prévios de aneurisma da aorta infeccioso causado por cândida em pacientes com otite externa maligna. Este relato de caso visa reforçar que a cândida deve ser uma das suspeitas de causa de aneurisma da aorta infeccioso em pacientes debilitados e com imunossupressão crônica. O manejo desses casos pode ser extremamente desafiador, principalmente em contextos em que os recursos são escassos, e mencionaremos as vantagens e desvantagens das diversas opções de tratamento.

Atualidades diagnósticas e terapêuticas na otite externa canina: revisão de literatura / Diagnostic and therapeutic updates on canine otitis externa: review / Actualidades diagnósticas y terapéuticas en la otitis externa canina: revisión de literatura

Objetivou-se revisar as principais atualidades diagnósticas e terapêuticas na otite externa canina. A otite externa é uma das principais doenças na rotina clínica de cães. Apresentando etiologia multifatorial e estando envolvidos agentes predisponentes, primários e perpetuantes. Os principais sinais clínicos incluem a otalgia, prurido e otorreia, à medida que se tornam crônicos podem ser encontrados estenose, hiperqueratose e hiperpigmentação, além disso casos graves podem evoluir para otite média e interna causando alterações sistêmicas como síndrome vestibular. O diagnóstico é baseado na apresentação clínica, citologia, cultura e antibiograma. Para o tratamento deve-se considerar a investigação das causas primárias de otite como endocrinopatias e doenças dermatológicas. O tratamento tópico é o mais indicado, sendo utilizados medicamentos compostos com antibiótico, antifúnqico e anti-inflamatório. Devido a alta casuística de casos de otites externas e ainda casos crônicos e de resistência ao tratamento é importante o estudo do manejo do paciente para a prevenção e o tratamento efetivo buscando alternativas que reduzam o uso de antibióticos.

The objective was to review the diagnostic and therapeutic trends in canine otitis externa. Otitis externa is one of the main causes of a new dog clinic. Presenting multifactorial and seasonal etiology predisposing agents, primary and perpetuating. The main clinical indications include the prevalence, hypertrophy and otorrhea, as they become chronic, can be exuded, hyperkeratosis and hyperpigmentation, the main processes can progress to the middle and the front as the systemic alterations such as the vestibular syndrome . The diagnosis is based on clinical presentation, cytology, culture and antibiogram. For treatment should be an investigation of the primary causes of otitis such as endocrinopathies and dermatological diseases. The topical treatment is the most indicated, being made compound drugs with antibiotic, antifungal and anti-inflammatory. Due to the high casuistry of cases of external otitis and other chronic occurrences and resistance to treatment, it is important to study the patient manual for prevention and effective treatment in search of alternatives that reduce the use of antibiotics.

Se objetivó revisar las principales novedades diagnósticas y terapéuticas en la otitis externa canina. La otitis externa es una de las principales enfermedades en la rutina clínica de perros. Presentando etiología multifactorial y estando in volucrados agentes predisponentes, primarios y perpetuantes. Los principales signos clínicos incluyen la otalgia, prurito y otorrea, a medida que se vuelven crónicos se pueden encontrar estenosis, hiperqueratosis e hiperpigmentación, además de casos graves pueden evolucionar a otitis media e interna causando alteraciones sistémicas como síndrome vestibular. El diagnóstico se basa en la presentación clínica, la citología, la cultura y el antibiograma. Para el tratamiento se debe considerar la investigación de las causas primarias de otitis como endocrinopatías y enfermedades dermatológicas. El tratamiento tópico es el más indicado, utilizando medicamentos compuestos con antibiótico, antifúngico y anti-inflamatorio. Debido a la alta casuística de casos de otitis externa y aún casos crónicos y de resistencia al tratamiento es importante el estudio del manejo del paciente para la prevención y el tratamiento efectivo buscando alternativas que reduzcan el uso de antibióticos.

Atualidades diagnósticas e terapêuticas na otite externa canina: revisão de literatura / Diagnostic and therapeutic updates on canine otitis externa: review / Actualidades diagnósticas y terapéuticas en la otitis externa canina: revisión de literatura

Objetivou-se revisar as principais atualidades diagnósticas e terapêuticas na otite externa canina. A otite externa é uma das principais doenças na rotina clínica de cães. Apresentando etiologia multifatorial e estando envolvidos agentes predisponentes, primários e perpetuantes. Os principais sinais clínicos incluem a otalgia, prurido e otorreia, à medida que se tornam crônicos podem ser encontrados estenose, hiperqueratose e hiperpigmentação, além disso casos graves podem evoluir para otite média e interna causando alterações sistêmicas como síndrome vestibular. O diagnóstico é baseado na apresentação clínica, citologia, cultura e antibiograma. Para o tratamento deve-se considerar a investigação das causas primárias de otite como endocrinopatias e doenças dermatológicas. O tratamento tópico é o mais indicado, sendo utilizados medicamentos compostos com antibiótico, antifúnqico e anti-inflamatório. Devido a alta casuística de casos de otites externas e ainda casos crônicos e de resistência ao tratamento é importante o estudo do manejo do paciente para a prevenção e o tratamento efetivo buscando alternativas que reduzam o uso de antibióticos.(AU)

The objective was to review the diagnostic and therapeutic trends in canine otitis externa. Otitis externa is one of the main causes of a new dog clinic. Presenting multifactorial and seasonal etiology predisposing agents, primary and perpetuating. The main clinical indications include the prevalence, hypertrophy and otorrhea, as they become chronic, can be exuded, hyperkeratosis and hyperpigmentation, the main processes can progress to the middle and the front as the systemic alterations such as the vestibular syndrome . The diagnosis is based on clinical presentation, cytology, culture and antibiogram. For treatment should be an investigation of the primary causes of otitis such as endocrinopathies and dermatological diseases. The topical treatment is the most indicated, being made compound drugs with antibiotic, antifungal and anti-inflammatory. Due to the high casuistry of cases of external otitis and other chronic occurrences and resistance to treatment, it is important to study the patient manual for prevention and effective treatment in search of alternatives that reduce the use of antibiotics.(AU)

Se objetivó revisar las principales novedades diagnósticas y terapéuticas en la otitis externa canina. La otitis externa es una de las principales enfermedades en la rutina clínica de perros. Presentando etiología multifactorial y estando in volucrados agentes predisponentes, primarios y perpetuantes. Los principales signos clínicos incluyen la otalgia, prurito y otorrea, a medida que se vuelven crónicos se pueden encontrar estenosis, hiperqueratosis e hiperpigmentación, además de casos graves pueden evolucionar a otitis media e interna causando alteraciones sistémicas como síndrome vestibular. El diagnóstico se basa en la presentación clínica, la citología, la cultura y el antibiograma. Para el tratamiento se debe considerar la investigación de las causas primarias de otitis como endocrinopatías y enfermedades dermatológicas. El tratamiento tópico es el más indicado, utilizando medicamentos compuestos con antibiótico, antifúngico y anti-inflamatorio. Debido a la alta casuística de casos de otitis externa y aún casos crónicos y de resistencia al tratamiento es importante el estudio del manejo del paciente para la prevención y el tratamiento efectivo buscando alternativas que reduzcan el uso de antibióticos.(AU)

Ocorrência de Staphylococcus spp. resistente à meticilina em otite externa canina / Occurrence of methicillin-resistant Staphylococcus spp. in canine external otitis

Objetivo: O presente estudo objetivou traçar o perfil de resistência dos isolados de Staphylococcus spp. resistentes à meticilina (SMR) em cães com otite externa proveniente de atendimentos ambulatoriais ou de internação. Métodos: Isolamento e identificação bacteriológica por meio de provas bioquímicas e testes de susceptibilidade a antibacterianos. Detecção do gene mecA por PCR e determinação da concentração bactericida mínima (CBM) ao gluconato de clorexidina. Resultados: Foram coletadas 140 amostras e, destas, foram isolados 122 Staphylococcus spp. (49,4%). Dos isolados bacterianos, 14 cepas (11,47%) foram SMR (oito coagulase positiva e seis coagulase negativa), apresentando o gene mecA. A concentração bactericida mínima ao gluconato de clorexidina para os Staphylococcus spp. coagulase positiva foi de 500.000 mg/mL (0,5%) e para os coagulase negativa foi de 62.500 mg/mL (0,0625%). Cinco SMR foram positivos para o teste-D. Os SMR foram 100% sensíveis à linezolida, cloranfenicol e rifampicina. Conclusão: Apesar da baixa frequência da multirresistência encontrada, existe a necessidade de monitoramento efetivo em estirpes isoladas de animais domésticos, garantindo o sucesso do tratamento e controle da resistência bacteriana em infecções otológicas caninas.

Objective: The objective of this study is to outline the resistance profile of methicillin-resistant Staphylococcus spp. (MRS) isolates from outpatient and inpatient care dogs diagnosed with otopathy. Methods: Isolation and bacteriological identification through biochemical tests and antibacterial susceptibility testing. Detection of mecA gene by PCR and determination of minimum bactericidal concentration (CBM) to chlorhexidine gluconate. Results: 140 samples were collected and from these 122 was Staphylococcus spp. (49.4%). Of all bacterial isolates 14 (11.47%) were MRS (eight coagulase positive and six coagulase negative) with mecA gene. The minimum bactericidal concentration to chlorhexidine guconate was 500,000 mg/mL (0.5%) for coagulase positive Staphylococcus spp. and 62,500 mg/mL (0.0625%) for coagulase negative. Five MRS were positive for D-test. The MRS were 100% sensitive to linezolide, chloramphenicol and rifampicin. Conclusion: Despite the low frequency of multiressitance found, there is a need for more effective monitoring in strains isolated from domestic animals to guarantee successful treatment and control of bacterial resistance in canine otological infections.

Genotyping of Malassezia pachydermatis disclosed genetic variation in isolates from dogs in Colombia / Genotipagem de Malassezia pachydermatis revelou variação genética em isolados de cães na Colômbia

Malassezia pachydermatis is a lipophilic and lipid-dependent yeast mostly isolated from animals' skin; hence, it is regarded as a zoophilic species causing otitis externa in dogs. Aspects associated with its epidemiology and pathogenicity is a matter of interest. This study aimed to conduct a molecular characterization of 43 isolates of M. pachydermatis obtained from dogs with otitis externa. For this purpose, the 5.8S internal transcribed spacer 2 (ITS2) and D1/D2 26S rRNA regions were amplified, sequenced and analyzed using restriction fragment length polymorphism (RFLP) with AluI, CfoI, and BstF5I endonucleases. Phylogenetic analyses revealed that these isolates grouped with the sequence types I, IV and V, previously proposed for M. pachydermatis. Interestingly, we found a new polymorphic RFLP pattern using BstF5I, these isolates were associated with the sequence types IV and V, nevertheless an association between polymorphic RFLP patterns, and fosfolipase activity or canine population data was not observed. These findings underline the genetic diversity of M. pachydermatis and provide new insights about the epidemiology of this species in the analyzed population.(AU)

Malassezia pachydermatis é uma levedura lipofílica e dependente de lipídios, principalmente da pele de animais. Sendo, por essa razão, considerada uma espécie zoofílica e causadora de otite externa em cães. Neste sentido, aspectos associados à sua epidemiologia e patogenicidade constituem um tema de interesse científico. O objetivo deste estudo foi realizar a caracterização molecular de 43 isolados de M. pachydermatis obtidos a partir de cães com otite externa. Para esta propósito, foram amplificadas, sequenciadas e analisadas com enzimas de restrição as regiões do gene 5.8S, do espaçador interno transcrito 2 (ITS2) e D1/D2 do 26S do rRNA pelo método RFLP, com as endonucleases AluI, CfOI e BstF5I. Análises filogenéticas revelaram que os isolados se agruparam com as sequências tipo I, IV e V de M. pachydermatis como já descrito anteriormente. De maneira interessante, se observou um novo RFLP polimórfico utilizando BstF5I. Os isolados que mostraram esse padrão foram associados com os padrões IV e V. No entanto, não foi observada associação entre padrões polimórficos de RFLP e atividade de fosfolipase ou dados da população canina. Estes resultados demonstram a diversidade genética de M. pachydermatis e fornecem novas perspectivas sobre a epidemiologia destas espécies na população analisada.(AU)

Genotyping of Malassezia pachydermatis disclosed genetic variation in isolates from dogs in Colombia / Genotipagem de Malassezia pachydermatis revelou variação genética em isolados de cães na Colômbia

Malassezia pachydermatis is a lipophilic and lipid-dependent yeast mostly isolated from animals' skin; hence, it is regarded as a zoophilic species causing otitis externa in dogs. Aspects associated with its epidemiology and pathogenicity is a matter of interest. This study aimed to conduct a molecular characterization of 43 isolates of M. pachydermatis obtained from dogs with otitis externa. For this purpose, the 5.8S internal transcribed spacer 2 (ITS2) and D1/D2 26S rRNA regions were amplified, sequenced and analyzed using restriction fragment length polymorphism (RFLP) with AluI, CfoI, and BstF5I endonucleases. Phylogenetic analyses revealed that these isolates grouped with the sequence types I, IV and V, previously proposed for M. pachydermatis. Interestingly, we found a new polymorphic RFLP pattern using BstF5I, these isolates were associated with the sequence types IV and V, nevertheless an association between polymorphic RFLP patterns, and fosfolipase activity or canine population data was not observed. These findings underline the genetic diversity of M. pachydermatis and provide new insights about the epidemiology of this species in the analyzed population.(AU)

Malassezia pachydermatis é uma levedura lipofílica e dependente de lipídios, principalmente da pele de animais. Sendo, por essa razão, considerada uma espécie zoofílica e causadora de otite externa em cães. Neste sentido, aspectos associados à sua epidemiologia e patogenicidade constituem um tema de interesse científico. O objetivo deste estudo foi realizar a caracterização molecular de 43 isolados de M. pachydermatis obtidos a partir de cães com otite externa. Para esta propósito, foram amplificadas, sequenciadas e analisadas com enzimas de restrição as regiões do gene 5.8S, do espaçador interno transcrito 2 (ITS2) e D1/D2 do 26S do rRNA pelo método RFLP, com as endonucleases AluI, CfOI e BstF5I. Análises filogenéticas revelaram que os isolados se agruparam com as sequências tipo I, IV e V de M. pachydermatis como já descrito anteriormente. De maneira interessante, se observou um novo RFLP polimórfico utilizando BstF5I. Os isolados que mostraram esse padrão foram associados com os padrões IV e V. No entanto, não foi observada associação entre padrões polimórficos de RFLP e atividade de fosfolipase ou dados da população canina. Estes resultados demonstram a diversidade genética de M. pachydermatis e fornecem novas perspectivas sobre a epidemiologia destas espécies na população analisada.(AU)

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.