Search

Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) being a constant concern, ceftaroline fosamil has been recently approved as a new cephalosporin, active against MRSA, for use in humans; only rare cases of resistance have been reported till date. There is no report of resistance to ceftaroline in Staphylococcus pseudintermedius, which is the main bacterium causing dermatitis and otitis in dogs. To evaluate staphylococcal resistance to ceftaroline, 35 isolates of methicillin-resistant S. pseudintermedius (MRSP), carrying the mecA gene, from 26 dogs with folliculitis and nine dogs with external otitis, underwent disk diffusion test with cefoxitin, oxacillin, and ceftaroline. Tests with cefoxitin and oxacillin showed > 90% sensitivity in methicillin resistance detection. In the disk diffusion test, 97.14% (34/35) were resistant to cefoxitin, 94.29% (33/35) to oxacillin, and 31.43% (11/35) to ceftaroline. Of the ceftaroline-resistant strains, 27.27% (3/11) were obtained from the ears of dogs while the rest (8/11) were from the skin. The current report is the first description of MRSP resistance to ceftaroline.

Canine atopic dermatitis (CAD) is a chronic, pruritic, genetic, and inflammatory disease. Its pathogenesis is very complex and involves skin barrier defects and immune system dysfunction. This study aimed to investigate hematological, biochemical, clinical, and immunological parameters to contribute to the identification of biomarkers applied to CAD. The results of the analysis on hematologic and clinical parameters showed increased neutrophil numbers and decreased lymphocyte counts. The ex vivo immunophenotyping of leukocytes demonstrated increased counts of circulating neutrophils, in addition to a high frequency of CD4+ T-cells and elevated CD4+/CD8+ T-cell ratio, which were the hallmark of atopic animals. Moreover, atopic dogs presented a mixed immune response, displaying both CD4+ and CD8+ T-cell subsets as relevant sources of IFN-γ and IL-4 cytokines. The morbidity analyzed by the CADESI index demonstrated that CAD severity is related to the low frequency of circulating CD14+ monocytes, CD21+ B-cells, and CD8+ T-cells. The reported biomarkers would be useful in CAD monitoring for treatment and prognosis analysis.

Otitis is a common condition among dogs and requires appropriate treatment. Given the importance of the otitis externa and the use of products to combat this condition, this study evaluated the in vitro antimicrobial abilities of six commercial ear cleaners solutions (EC1 to EC6) and solutions of 3% boric acid, 3% lactic acid, 0.11% salicylic acid, 0.5% chlorhexidine, and 3% propylene glycol against Staphylococcus spp., Pseudomonas spp., Proteus spp., and Malassezia spp. The in vitro diffusion capacity in synthetic cerumen was also assessed. Dogs with clinical signs of otitis externa were selected and samples were collected from the external ear canals. The microbiological study was performed to identify the microorganisms from samples collected and the microorganisms isolated were used in the study. One ceruminolytic for human use and five commercial solutions used for canine ear cleaning were selected based on the diversity of the components used in each formula. The results show a variation of antimicrobial activity and diffusion capacity ear cleaners and its compounds. Lactic acid, chlorhexidine, EC1, EC2, EC4, and EC5 showed the best results for microbiological growth inhibition; boric acid, salicylic acid, propylene glycol and EC6 had little or no effect on microorganism growth. The ECs tested demonstrated diffusion capacity using the SSC. EC1 was the solution with the most significant responses, both as an antimicrobial agent and with regards to diffusion capacity. Among the commercial veterinary products tested, EC4 was found to have the best results. La otitis es una afección común entre los perros y requiere un tratamiento adecuado. Dada la importancia de la otitis externa y el uso de productos para combatir esta condición, este estudio evaluó las capacidades antimicrobianas in vitro de seis soluciones comerciales de limpiadores de oídos (EC1 a EC6) y soluciones de ácido bórico 3%, ácido láctico 3%, 0.11 % de ácido salicílico, 0,5% de clorhexidina y 3% de propilenglicol contra Staphylococcus spp., Pseudomonas spp., Proteus spp. y Malassezia spp. También se evaluó la capacidad de difusión in vitro en cerumen sintético. Se seleccionaron perros con signos clínicos de otitis externa y se recolectaron muestras de los conductos auditivos externos. El estudio microbiológico se realizó para identificar los microorganismos que se utilizaron en el estudio. Se seleccionaron un ceruminolítico para uso humano y cinco soluciones comerciales utilizadas para la limpieza de oídos caninos en función de la diversidad de los componentes. Los resultados muestran una variación de la actividad antimicrobiana y la capacidad de difusión. El ácido láctico, la clorhexidina, EC1, EC2, EC4 y EC5 mostraron los mejores resultados para la inhibición del crecimiento microbiológico; El ácido bórico, el ácido salicílico, el propilenglicol y el EC6 tuvieron poco o ningún efecto sobre el crecimiento de microorganismos. Las CE probadas demostraron capacidad de difusión utilizando el SSC. EC1 fue la solución con las respuestas más significativas, tanto como agente antimicrobiano como en cuanto a capacidad de difusión. Entre los productos veterinarios comerciales probados, se encontró que EC4 tenía los mejores resultados. A otite é uma condição comum entre os cães e requer tratamento adequado. Dada a importância da otite externa e do uso de produtos para combater essa condição, este estudo avaliou a atividade antimicrobiana in vitro de seis soluções de limpeza de ouvido comerciais (EC1 a EC6) e soluções de ácido bórico 3%, ácido lático 3%, 0,11 % de ácido salicílico, 0,5% de clorexidina e 3% de propilenoglicol contra Staphylococcus spp., Pseudomonas spp., Proteus spp. e Malassezia spp. A capacidade de difusão in vitro em cerúmen sintético também foi avaliada. Cães com sinais clínicos de otite externa foram selecionados e amostras foram coletadas dos canais auditivos externos. O estudo microbiológico foi realizado para identificar os microrganismos das amostras coletadas e os microrganismos isolados foram utilizados no estudo. Um ceruminolítico para uso humano e cinco soluções comerciais para limpeza auricular canina foram selecionadas com base na diversidade dos componentes utilizados em cada fórmula. Os resultados mostram uma variação na atividade antimicrobiana e na capacidade de difusão dos limpadores de ouvido e seus compostos. Ácido láctico, clorexidina, EC1, EC2, EC4 e EC5 mostraram os melhores resultados para inibição do crescimento microbiano; ácido bórico, ácido salicílico, propilenoglicol e EC6 tiveram pouco ou nenhum efeito no crescimento do microrganismo. As soluções testadas demonstraram capacidade de difusão usando o SSC. EC1 foi a solução com as respostas mais significativas, tanto como agente antimicrobiano quanto em relação à capacidade de difusão. Entre os produtos veterinários comerciais testados, o EC4 apresentou os melhores resultados.

Background Limited information is available describing the features of canine atopic-like dermatitis (ALD) compared with atopic dermatitis (AD). Objectives To compare demographic data, disease severity and response to therapy between ALD and AD dogs. Animals Two hundred and fifty-three atopic dogs with intradermal and serum allergen-specific IgE test results were selected retrospectively. Methods and materials Dogs were enrolled into the ALD group if both IgE tests were negative and into the AD group if at least one test was positive. Demographic data, pruritus level and number of body sites affected before and during therapy, in addition to maintenance therapy protocols, were compared between groups. Results There were 216 (85.38%) dogs in the AD group and 37 (14.62%) in the ALD group. The soft-coated wheaten terrier, American Staffordshire terrier, English bulldog and Labrador retriever were over-represented in the AD group. No significant differences between the groups were noted regarding the other demographic variables evaluated. There were no differences in the mean pruritus scores and number of affected body sites at the first visit or during treatment. Furthermore, no significant differences between the groups were noted for the maintenance treatment scores and reduction of pruritus level and number of body sites affected during treatment. Conclusions and clinical significance The soft-coated wheaten terrier, American Staffordshire terrier, English bulldog and Labrador retriever were over-represented in the AD group. No significant differences in the other demographic data and clinical features were noted between dogs with ALD and AD in the present study.

EnglishInfections by Staphyloccocus pseudintermedius in the skin of dogs have been object of studies, since such microorganisms often present multiple resistance to antibiotics. This study aimed to identify and evaluate the antimicrobial susceptibility of Staphylococcus pseudintermedius (SP) strains isolated from dogs with otitis. Swabs from both ears of 52 dogs with otitis (n=104) were included. Bacteria were cultured using Muller-Hinton agar (supplemented with 5% equine blood and incubated at 37°C for 24 to 48 hours. All colonies underwent biochemical evaluation for identification of staphylococci. The identity of colonies as SP was confirmed by polymerase chain reaction. The antimicrobial susceptibility of SP strains was evaluated by disk diffusion. The presence of the gene mecA was evaluated in all SP isolates by PCR. Forty-four SP strains were isolated from swabs of 31 dogs (31/52, 59.6%). Seventy-five percent of the strains were susceptible to cephalexin and 93.2% to amoxicillin plus clavulanic acid. Less than 23% of the strains were susceptible to penicillin. For non-beta-lactam antimicrobials, 63.6% of the strains showed resistance to sulfamethoxazole-trimethoprim, 61.4% to tetracycline, and 38, 64% to enrofloxacin. Aminoglycoside resistance rate was 27.3% for gentamicin. Resistance to oxacillin in vitro was detected in 13 of the 44 strains (29, 55%). A total of 12 strains (27.3%) were positive for mecA gene and five of these 12 strains were susceptible to in vitro oxacillin. Twenty-six (59, 1%) strains were resistant to three or more classes of antimicrobials, and classified as multi resistant. Our results showed high frequency of SP and multi resistant isolates to antimicrobials commonly used in veterinary. Key words: dogs; MRSP; methicillin-resistant staphylococcus; otitis portuguesInfeccoes por Staphyloccocus pseudintermedius (SP) na pele de caes tem sido objeto de estudos, uma vez que esses microrganismos geralmente apresentam resistencia multipla a antibioticos. Este estudo teve como objetivo identificar e avaliar a susceptibilidade antimicrobiana das cepas de SP isoladas de caes com otite. Amostras de ambas orelhas de 52 caes com otite (n=104) foram incluidas. As bacterias foram cultivadas em agar Muller-Hinton suplementado com 5% de sangue equino e incubadas a 37oC por 24 a 48h. Todas as colonias foram submetidas a avaliacao bioquimica para identificacao de estafilococos. A identificacao das colonias como SP foi confirmada pela reacao em cadeia da polimerase. A susceptibilidade antimicrobiana das cepas SP foi avaliada pela tecnica de difusao em disco. A presenca do gene mecA foi avaliada em todos os isolados de SP por PCR. 44 estirpes de SP foram isoladas de 31 caes (31/52, 59,6%). 75% das cepas foram suscetiveis a cefalexina e 93,2% a amoxicilina mais acido clavulânico. Menos de 23% das estirpes eram suscetiveis a penicilina. Para antimicrobianos nao beta-lactâmicos, 63,6% apresentaram resistencia ao sulfametoxazol-trimetoprim, 61,4% a tetraciclina e 38,64% a enrofloxacina. A frequencia de resistencia a aminoglicosideos foi de 27,3% para gentamicina. A resistencia a oxacilina in vitro foi detectada em 13 das 44 estirpes (29,55%). Um total de 12 amostras (27,3%) foram positivas para mecA, cinco das quais foram suscetiveis a oxacilina na difusao em disco. 26 amostras (59,1%) foram resistentes a tres ou mais classes de antimicrobianos e classificadas como multirresistentes. Nossos resultados mostram elevada frequencia de isolados SP e multiresistentes para os antimicrobianos comumente usados em veterinaria. Palavras-chave: caes; MRSP; otite; Staphylococcus resistente a meticilina

A dermatite atopica (DA) e uma doenca cutanea pruriginosa, inflamatoria, cronica associada a anticorpos IgE alergeno-especificos principalmente voltados contra alergenos ambientais. A DA afeta diversas especies, incluindo caes e humanos e o prurido e o seu principal sinal clinico. Alemdisso, caes atopicos tendem a apresentar quadros recorrentes de piodermites bacterianas, associadas a alteracoes no microbioma tegumentar. Em alguns casos, os pacientes apresentam sinais clinicos tipicos de DA, mas anticorpos IgE alergeno-especificos nao podem ser detectados. Este subtipo de DA e chamado de dermatite atopica-like (ALD). Tanto as alteracoes no microbioma em caes atopicos quanto as caracteristicas da ALD ainda sao pouco estudadas em caes. Sendo assim, objetivou-se avaliar estes dois parametros distintos da DA. Para tal, o presente estudo foi dividido em duas partes. Na primeira parte, realizou-se um estudo retrospectivo dos prontuarios de 269 caes atendidos no hospital veterinario universitario da University of Minnesota, entre 2007 e 2015. Os pacientes foram divididos em dois grupos (AD e ALD) de acordo com os resultados dos testes alergicos. Foram avaliados e comparados entre os grupos dados epidemiologicos, gravidade da doenca de acordo com o grau de prurido, numero de areas corporeas afetadas, protocolo de tratamento de manutencao e resposta a terapia. A partir do grau medio de prurido e do numero medio de areas corporeas afetadas ao longo das visitas, foi criadoum indice de gravidade da dermatite atopica (CADSI) para se avaliar a intensidade da doenca em cada paciente e comparar entre os grupos ALD e AD. No grupo AD foram incluidos 228 caes (84,76%) e 41 no grupo ALD (15,24%). Nao foram observadas diferencas significativas entre os grupos nas variaveis epidemiologicas. Em relacao a predisposicao racial, o Bichon Frise apresentou mais risco de desenvolver ALD. Nao houve diferenca significativa no grau medio de prurido e numero de areas corporeas afetadas na primeira visita ou durante o tratamento entre os grupos, bem como na evolucao dessas variaveis ao longo das visitas. Quando o CADSI foicomparado entre os grupos, nao houve diferenca. Na segunda parte, foram selecionados prospectivamente sete caes atopicos com manifestacoes clinicas sazonais, alocados no Grupo Atopico (GA) e dez caes saudaveis, alocados no Grupo Controle (GC) e amostras foram coletadas da regiao interdigital, axilar, abdominal e lombar utilizando um suabe esteril. No GC, realizou-se seis coletas intervaladas de quatro semanas. No GA, as amostras foram coletadas quatro semanas antes do mes tipico de crise (Pre-crise), na crise antes de iniciar o tratamento (Crise), durante acrise com tratamento (Tratamento) e apos a estacao de crise, ja sem tratamento (Pos-crise). Apos as coletas, as amostras foram armazenadas refrigeradas por no maximo sete dias ate a extracao do DNA e sequenciamento do gene 16S rRNA. Apos o processamento, foi feita a analise bioinformatica e estatistica para avaliacao taxonomica e calculo de alpha e beta-diversidade. Os filos mais abundantes em todas as amostras foram Actinobacteria, Firmicutes, Fusobacteria e Proteobacteria. Observou-se que a diversidade do microbioma cutaneo de caes atopicos sofre reducao no Pre-crise e o tratamento imunomodulador e capaz de restabelece-la. Estes resultados sao muito relevantes e promissores pois demonstram as alteracoes na diversidade do microbioma antes mesmo do surgimento dos sinais clinicos da doenca e o papel restaurador da terapiaimunomoduladora, sem o uso de antimicrobianos. Atopic dermatitis (AD) is a chronic inflammatory, pruritic skin disease associated with allergenspecific IgE antibodies primarily against environmental allergens. AD affects several species, including dogs and humans. Pruritus is the main clinical sign of AD. In addition, atopic dogs tendto present recurrent superficial pyoderma, associated with alterations in the skin microbiome. In some cases, patients show typical clinical signs of AD, but allergen-specific IgE antibodies cannot be detected. This subtype of AD is called atopic-like dermatitis (ALD). Both the alterations in the skin microbiome of atopic dogs and the features of ALD are still poorly understood in dogs. Thus, we aimed to evaluate these two distinct parameters of AD. So, the present study was divided in two parts. In the first part, a retrospective study of the medical records of 269 dogs seen at the veterinary teaching hospital of the University of Minnesota between 2007 and 2015 was performed. Patients were divided in two groups (AD and ALD) according to the allergy testsresults. Epidemiological data, disease severity according pruritus level, number of affected body sites, maintenance treatment protocol and response to therapy were evaluated and compared between the groups. The mean pruritus level and the mean number of body sites affected across visits, the Canine Atopic Dermatitis Severity Index (CADSI) was created to assess the severity of the disease in each patient and to compare ALD and AD. In the AD group, 228 dogs (84.76%) were included and in the ALD group, 41 (15.24%). There were no significant differences between the groups in the epidemiological variables. In relation to breed predisposition, Bichon Frisé was more predisposed to developing ALD. There was no significant difference in the mean pruritus level and number of affected areas at the first visit or during treatment between groups, as well as in the outcome of these variables throughout the visits. When CADSI was compared betweengroups, there was no significant difference. In the second part, were selected prospectively seven seasonal atopic dogs, Atopic Group (GA), and ten healthy dogs, Control Group (CG). Samples were collected from the interdigital, axillary, abdominal and lumbar regions from each dog usinga sterile swab. In GC, six collections in a of four week interval were performed. In GA, the samples were collected four weeks prior the typical flare month (Pre-crisis), in the flare before starting the treatment (Flare), during the flare with treatment (Treatment) and after the flare seasonwithout treatment (Post-flare). After collection, samples were stored refrigerated for up to seven days until DNA extraction and sequencing of the 16S rRNA gene. After processing, bioinformatic and statistical analysis were performed for taxonomic evaluation and alpha and beta-diversityassessment. The most abundant phyla in all samples were Actinobacteria, Firmicutes, Fusobacteria and Proteobacteria. It was observed that the diversity of the cutaneous microbiome of atopic dogs undergoes a reduction the Pre-flare and the immunomodulatory treatment is able to reestablish it. These results are very relevant and promising as they demonstrate changes in microbiome diversity even before the inflammatory response of the disease and the restorative role of immunomodulatory therapy without the use of antimicrobials.

Demodicosis is a common parasitary dermatopathy in dogs, resulting from excessive proliferation of Demodex canis mite , a natural inhabitant of dog´s skin. Definitive diagnosis is classically established through microscopic examination of deep skin scrapings obtained from affected areas, in which numerous adult mites and/or immature forms are observed. Although considered as the golden pattern for the disease diagnosis, this technique is difficult to be performed in some parts of the body, as face, eyelids and interdigital areas, besides causing pain in the dog and discomfort to the owner. Two less invasive diagnostic methods, the hair plucking and the adhesive tape test are described. Although these methods are well known, only few studies about their sensitivity were found in the literature. In the present study, tests were conducted on 40 dogs previously diagnosed with demodicosis through deep skin scrapings. At adhesive tape test, 30 of 40 samples were positive, evidencing 75% of sensivity, while at hair plucking, mites were observed in 29 samples, leading to a sensivity of 73%. These results do not differ statistically and suggest that adhesive tape test and hair plucking tests can be used on clinical routine as first choice primary tests for canine demodicosis as they offer more comfort to animal and its owner. Interestingly, the presence of pyoderma raised the sensibility of both tests to 100%. However, deep skin scrapings must be done for diagnosis confirmation whenever the results of these two methods are negative.

O Staphylococcus pseudintermedius é a bactéria mais comumente isolada de cães e está frequentemente associada à piodermites e otites nesses animais. Atualmente, tem sido descrito o Staphylococcus pseudintermedius resistente à meticilina (MRSP). Estes microorganismos são portadores do gene mecA, responsável pela transcrição da proteína PBP2a que reduz a susceptibilidade dessas bactérias a todos os antibióticos betalactâmicos. O objetivo deste estudo foi avaliar a prevalência de MRSP em cães com piodermite superficial atendidos no Hospital Veterinário da UFMG. Foram selecionados para o estudo 43 cães com piodermite superficial diagnosticados por exame físico e dermatológico entre março e julho de 2013. Dos animais selecionados, 75% tinham histórico de antibioticoterapia prévia. Foram coletadas amostras em haste de algodão estéril de secreção de lesões de pele e narina direita. As amostras foram cultivadas em ágar sangue de carneiro e, posteriormente, avaliadas fenotipicamente e genotipicamente. Na identificação fenotípica, 88% dos isolados foram classificados como bactéria do SIG (Staphylococcus pseudintermedius Group). Na identificação genotípica para classificação como Staphylococcus pseudintermedius, este número cresceu para 91%, demonstrando correlação significativa com o resultado da identificação bioquímica. Observou-se correlação significativa entre a espécie identificada nas lesões de pele e narinas. No antibiograma a prevalência de resistência foi de 7% a amicacina, 23% a amoxacilina + clavulanato, 24% a cefalexina, 18% ao cloranfenicol, 38% a enrofloxacina, 40% a estreptomicina, 30% a gentamicina, 34% a oxacilina, 77% a penicilina, 6% a polimixina B, 62% a tetraciclina e 77% a sulfa + trimetoprim. Trinta e cinco porcento das amostras apresentava o gene mecA, demonstrando correlação significativa com a frequência de resistência à oxacilina. Observou-se também correlação significativa entre a prevalência de mecA nas narinas e lesões de pele. Não houve correlação entre a antibioticoterapia prévia e a frequência de gene mecA nas amostras. Desta forma, conclui-se que o S. pseudintermedius é a bactéria mais prevalente em piodermite canina e o gene mecA está significativamente presente nas lesões e narinas dos animais testados. Staphylococcus pseudintermedius is the most commonly isolated bacteria in dogs and is often associated with pyoderma and otitis in these animals. In the past years, methicillin resistant Staphylococcus pseudintermedius (MRSP) was described. These microorganisms have in there genome the mecA gene, responsible for the transcription of the PBP2a protein that reduces the susceptibility of these bacteria to all beta - lactamic antibiotics. The aim of this study was to evaluate the frequency of MRSP in dogs with superficial pyoderma presented at the Veterinary Hospital of UFMG. Forty-three dogs with superficial pyoderma were selected for the study diagnosed by physical and dermatological examination from march to July of 2013. From the selected animals, 75% had a history of prior antibiotic therapy. The samples were collected in sterile swab secretion of skin lesions and right nostril and were streaked on sheep blood agar and subsequently evaluated phenotypically and genotypically. At the phenotypic identification, 88 % of the isolates were classified as SIG (Staphylococcus pseudintermedius Group). At the genotypic identification for classification as Staphylococcus pseudintermedius, this number grows to 91 %, showing a significant correlation with the result of biochemical identification. A significant correlation between the species identified in skin lesions and nostrils. In the antibiogram, prevalence of resistance was amikacin 7% to 23% amoxicillin + clavulanate , 24% cephalexin , chloramphenicol 18% , 38% enrofloxacin 40% streptomycin , gentamicin 30% , 34% oxacillin, 77% penicillin , polymyxin B 6% , 62% and 77% tetracycline trimethoprim sulfa . Thirty-five percent of the samples had the mecA gene, demonstrating a significant correlation with the prevalence of oxacillin resistance. We also observed a significant correlation between the frequency of mecA in the lesions and nostrils. There was no correlation between previous antibiotic therapy and frequency of mecA gene in samples. In conclusion, S. pseudintermedius is the most common bacteria in canine pyoderma and the mecA gene is present in significant frequency in the lesions and nostrils of the tested animals.

CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior O gênero Staphylococcus apresenta grande relevância para a medicina humana e medicina veterinária, sendo composto por mais de 40 espécies. Pode ser encontrado como parte da microbiota natural de animais e humanos, mas também como agente oportunista em processos infecciosos. Entre as espécies encontradas em cães, destaca-se S. pseudintermedius – uma importante bactéria comensal da pele e mucosas, que também pode ser responsável por infecções clínicas como piodermites, otites e infecções de sítio cirúrgico (SSIs). O surgimento de estirpes de S. pseudintermedius resistentes à meticilina (MRSP) tornou-se um problema de importante de saúde pública, uma vez que estas são multirresistentes e podem infectar também seres humanos. O objetivo deste estudo foi identificar e caracterizar estirpes de S. pseudintermedius isoladas de diferentes sítios infecciosos em cães quanto à sua diversidade genética e resistência a antimicrobianos de uso em medicina humana e medicina veterinária. As amostras foram obtidas em duas clínicas veterinárias diferentes de Belo Horizonte; colônias sugestivas foram identificadas por MALDI-TOF e confirmadas por PCR ou sequenciamento dos genes 16S rRNA ou rpoB. Fora realizado teste de susceptibilidade antimicrobiana e detecção por PCR do gene mecA em todas as amostras. Os isolados de MRSP foram submetidos ainda à técnica de multilocus sequence typing. Cerca de 74,8% dos isolados clínicos eram S. pseudintermedius. Multirresistência (MDR) foi observada em 63,2% dos isolados de S. pseudintermedius e cerca de 24,5% foram MRSP. Metade dos isolados MRSP foi encontrado em SSIs. Entre os dez sequence types (ST) identificados, nove foram identificados pela primeira vez na literatura. O complexo clonal (CC) 71 foi o CC mais frequente e foi associado à resistência a fluorquinolonas. Tratamento antimicrobiano prévio, hospitalização e SSIs foram identificados como fatores de risco para aquisição da MRSP. O presente trabalho confirmou que S. pseudintermedius é a principal espécie de estafilocócica isolada em partir de cachorros infectados em Belo Horizonte, além de identificar uma alta taxa de estirpes MDR. SSIs foram responsáveis pela maior taxa de estirpes MRSP. Além disso, este é o primeiro que investigou a estrutura populacional de MRSP em Minas Gerais, revelando a dispersão de um CC bem consolidado, além de novas linhagens. Os resultados encontrados são de relevância para a saúde pública, uma vez que a bactéria apresenta importante potencial zoonótico e as opções terapêuticas disponíveis são limitadas. Staphylococcus pseudintermedius is a major commensal bacterium of the skin and mucosae of dogs and an opportunistic agent responsible for several clinical infections, such as pyoderma, otitis, and surgical wound infections. The emergence of methicillin-resistant S. pseudintermedius (MRSP) has become a problem of great concern in veterinary and human medicine because it is multidrug resistant (MDR) and can also infect humans. This study aimed to identify the occurrence of S. pseudintermedius strains in infected patients and investigate the antimicrobial resistance profiles and molecular structure of MRSP isolates. Samples were obtained from two different veterinary clinics; suggestive colonies were submitted to matrix-assisted laser desorption ionization-time of flight (MALDI-ToF) mass spectrometry and confirmed at the species level by polymerase chain reaction (PCR) or sequencing of the 16S rRNA and rpoB genes. Antimicrobial susceptibility and PCR detection of mecA were performed. MRSP isolates were subjected to multilocus sequence typing. Of all the clinical staphylococci (n=131), 98 (74.8%) were identified as S. pseudintermedius. Multidrug resistance (resistance to ≥3 classes of antimicrobials) was observed in 63.2% of S. pseudintermedius isolates, and 24.5% of S. pseudintermedius isolates were MRSP. Half of the MRSP isolates were isolated from surgical site infections. Among the ten sequence types (ST) identified, nine were novel. ST71 was the most prevalent and associated with resistance to fluoroquinolones. Prior antimicrobial therapy, hospitalization, and surgical site infections seemed to be risk factors for MRSP acquisition. The present study showed a high rate of MDR staphylococci in infected dogs. MRSP was isolated from different clinical conditions, mainly surgical site infections. Additionally, this is the first study to extensively investigate the population structure of MRSP in Minas Gerais, which revealed the dispersion of CC71 and nine novel STs. These findings raise concerns for both animal and human health due to the zoonotic potential of this species and limited therapeutic options available for MRSP infections.