RESUMO: Foram investigados a etiologia, o índice de resistência múltipla aos antibióticos e o perfil de proteínas de fase aguda, no soro ou líquido sinovial, de 44 equinos com sinais clínicos compatíveis com artrite séptica. Foram amostrados animais até 24 meses de idade não submetidos a doma. As amostras de líquido sinovial dos 44 animais foram submetidas à cultura bacteriológica e fúngica, e os isolados bacterianos submetidos in vitro diante de 18 antimicrobianos visando investigar a multirresistência. Também foram avaliados os aspectos hematológicos e o fibrinogênio sérico, bem como os níveis séricos de certas proteínas de fase aguda (proteína total, albumina, globulina, amilóide sérico A e proteína C reativa). O isolamento microbiano das amostras foi dividido em quatro grupos: G1 = animais com isolamento negativo; G2 = isolamento de bactérias Gram-negativas; G3 = isolamento de bactérias Gram-positivas e G4 = isolamento fúngico. O isolamento microbiano foi obtido em 77,2% (32/44) das amostras de líquido sinovial. Escherichia coli (7/44 = 15,9%), Staphylococcus aureus (5/44 = 11,4%), Streptococcus equi subsp. equi (3/44 = 6,8%), Aspergillus niger (3/44 = 6,8%), Pseudomonas aeruginosa (2/44 = 4,5%), Streptococcus equi subsp. zooepidemicus (1/44 = 2,3%), Trueperella pyogenes (1/44=2,3%) e Rhodococcus equi (1/44 = 2,3%) foram os patógenos mais frequentes. Aspergillus niger é relatado pela primeira vez como agente primário de artrite séptica em cavalos. Gentamicina (84,9%), marbofloxacino (79,3%) e ceftriaxona (72,4%) foram os antimicrobianos mais eficazes, enquanto elevada resistência dos isolados (>50%) foi encontrada para eritromicina (75,9%), claritromicina (75,9%), penicilina (69%), clindamicina (58,6%) e estreptomicina (55,2%). O índice de resistência múltipla aos antibióticos (≥ 0,3) foi identificado em 50% (16/32) dos isolados, com maior resistência obervada em bactérias Gram-negativas. Os níveis séricos de amilóide A, proteína C reativa, fibrinogênio, globulina e concentração total de proteínas, bem como o número de células nucleadas no líquido sinovial apresentaram valores acima da referência para equinos saudáveis, reforçando o uso destas proteínas de fase aguda como biomarcadores no diagnóstico da doença. O presente estudo enfatiza a diversidade de microrganismos que podem estar envolvidos na artrite séptica equina, a alta resistência dos isolados aos antimicrobianos convencionais, a alta mortalidade de equinos jovens com artrite séptica e a importância de realizar o tratamento da afecção com respaldo em testes de sensibilidade microbiana in vitro.

ABSTRACT: Etiology, multiple antibiotic resistance index, and acute-phase protein profile in the serum and synovial fluid of 44 horses presenting septic arthritis were investigated. Young animals up to 24 months of age not yet submitted to taming were sampled. Synovial samples from the horses were submitted to culture and bacterial isolates subjected to 18 antimicrobials to investigate the in vitro multidrug resistance pattern. Also, hematological aspects, fibrinogen, and serum levels of some acute-phase proteins (total protein, albumin, globulin, amyloid A, and C-reactive protein) were assessed. To statistical analysis, microbiological isolation were divided into four groups: G1 = animals with negative isolation, G2 = isolation of Gram-negative bacteria, G3 = isolation of Gram-positive bacteria), and G4 = isolation of fungi. Microbial isolation was obtained from 77.2% (32/44) of the synovial samples. Escherichia coli (7/44 = 15.9%), Staphylococcus aureus (5/44 = 11.4%), Streptococcus equi subsp. equi (3/44 = 6.8%), Aspergillus niger (3/44 = 6.8%), Pseudomonas aeruginosa (2/44 = 4.5%), Streptococcus equi subsp. zooepidemicus (1/44 = 2.3%), Trueperella pyogenes (1/44 = 2.3%), and Rhodococcus equi (1/44 = 2.3%) were prevalent bacterial agents. Aspergillus niger is reported by the first time as a primary agent of septic arthritis in horses. Gentamicin (84.9%), marbofloxacin (79.3%) and ceftriaxone (72.4%) were the most effective antimicrobials, whereas high resistance of the isolates (>50%) was found to erythromycin (75.9%), clarithromycin (75.9%), penicillin (69%), clindamycin (58.6%), and streptomycin (55.2%). Multiple antibiotic resistance index (≥ 0.3) was identified in 50% (16/32) of the isolates, with highest resistance in Gram-negative bacterial isolates. Serum levels of amyloid A, C-reactive protein, fibrinogen, globulin, and total protein, as well as the number of nucleated cells in the synovial fluid had values above the reference for horses, reinforcing acute-phase proteins as biomarkers in diagnosis of septic arthritis. We highlighted the diversity of microorganisms that may be involved in equine septic arthritis, the high resistance of bacterial isolates to conventional antimicrobials, the high lethality of young horses with septic arthritis, and importance of in vitro antimicrobial susceptibility pattern tests to therapeutic approaches in the disease.

ABSTRACT Although the tuberculin test represents the main in vivo diagnostic method used in the control and eradication of bovine tuberculosis, few studies have focused on the identification of mycobacteria in the milk from cows positive to the tuberculin test. The aim of this study was to identify Mycobacterium species in milk samples from cows positive to the comparative intradermal test. Milk samples from 142 cows positive to the comparative intradermal test carried out in 4,766 animals were aseptically collected, cultivated on Lowenstein-Jensen and Stonebrink media and incubated for up to 90 days. Colonies compatible with mycobacteria were stained by Ziehl-Neelsen to detect acid-fast bacilli, while to confirm the Mycobacterium genus, conventional PCR was performed. Fourteen mycobacterial strains were isolated from 12 cows (8.4%). The hsp65 gene sequencing identified M. engbaekii (n=5), M. arupense (n=4), M. nonchromogenicum (n=3), and M. heraklionense (n=2) species belong to the Mycobacterium terrae complex. Despite the absence of M. tuberculosis complex species in the milk samples, identification of these mycobacteria highlights the risk of pathogen transmission from bovines to humans throughout milk or dairy products, since many of mycobacterial species described here have been reported in pulmonary and extrapulmonary diseases both in immunocompetent and immunocompromised people.

ABSTRACT Tuberculosis remains as the world’s biggest threat. In 2014, human tuberculosis ranked as a major infectious disease by the first time, overcoming HIV death rates. Bovine tuberculosis is a chronic disease of global distribution that affects animals and can be transmitted to humans by the consumption of raw milk, representing a serious public health concern. Despite the efforts of different countries to control and eradicate bovine tuberculosis, the high negative economic impact on meat and milk production chains remains, given the decreased production efficiency (approximately 25%), the high number of condemned carcasses, and increased animal culling rates. This scenario has motivated the establishment of official programs based on regulations and diagnostic procedures. Although Mycobacterium tuberculosis and Mycobacterium bovis are the major pathogenic species to humans and bovines, respectively, nontuberculous mycobacteria within the Mycobacterium genus have become increasingly important in recent decades due to human infections, including the ones that occur in immunocompetent people. Diagnosis of mycobacteria can be performed by microbiological culture from tissue samples (lymph nodes, lungs) and secretions (sputum, milk). In general, these pathogens demand special nutrient requirements for isolation/growth, and the use of selective and rich culture media. Indeed, within these genera, mycobacteria are classified as either fast- or slow-growth microorganisms. Regarding the latter ones, incubation times can vary from 45 to 90 days. Although microbiological culture is still considered the gold standard method for diagnosis, molecular approaches have been increasingly used. We describe here an overview of the diagnosis of Mycobacterium species in bovine milk.

RESUMO: A dermatofilose bovina é uma dermatite caracterizada por lesões focais ou localizadas com aspecto de “pincel” e, ocasionalmente, como lesão cutânea disseminada. Relata-se o caso de uma fêmea bovina de um ano de idade, que foi atendida apresentando história de lesões cutâneas crônicas imediatamente após um período de alta pluviosidade. Ao exame clínico, lesões serosas a purulentas, com hiperqueratose, coalescentes, não pruriginosas, ressecadas, de coloração amarelada à acinzentada foram observadas distribuídas de modo generalizado pelo animal. A remoção das crostas revelou áreas ulceradas ou hemorrágicas, com crostas irregulares e elevadas semelhantes a “pincel”. O diagnóstico microbiológico possibilitou a identificação do micro-organismo Dermatophilus congolensis. Apesar das lesões disseminadas e crônicas, a cura do animal foi obtida com tratamento parenteral usando oxitetraciclina de longa duração, baseado em teste in vitro de sensibilidade microbiana modificado. O presente relato ressalta o sucesso no tratamento de caso incomum de lesões generalizadas de dermatofilose bovina com respaldo de teste in vitro de sensibilidade modificado, bem como a necessidade do uso responsável de antimicrobianos em animais de produção.

ABSTRACT: Bovine dermatophilosis is a dermatitis characterized by typical focal or localized lesions with “paintbrush” aspect and occasionally as disseminated cutaneous disease. We report the case of a one-year-old Nelore female with history of chronic cutaneous disseminated lesions that appeared immediately after a rainfall period. Serous to purulent exudates, hair with tufted appearance, hyperkeratotic, non-pruritic, hardened, yellowish to brown, and coalescent crusty lesions were observed distributed all over its body. Removal of the crusts revealed ulcerated or hemorrhagic areas, with irregular elevated crusts like “paintbrush”. Microbiological diagnosis enabled the identification of a microorganism, the Dermatophilus congolensis. Despite disseminated and chronic lesions, we obtained a successful therapy with parenteral therapy using long-acting tetracycline based on modified in vitro disk diffusion test. The present report highlights success therapy in uncommon generalized bovine dermatophilosis with selection of first-choice drugs based on modified in vitro susceptibility test, and need of responsible use of antimicrobials in livestock.