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Abstract Bovine infectious mastitis is largely resistant to antibacterial treatment, mainly due to mechanisms of bacterial resistance in the biofilms formed by Staphylococcus aureus. Melaleuca (MEO) and citronella essential oils (CEO) are promising agents for reducing or eliminating biofilms. Free melaleuca oil presented a medium Minimum Inhibitory Concentration (MIC) of 0.625% and a Minimum Bactericidal Concentration (MBC) of 1.250%, while free citronella oil showed medium MIC and MBC of 0.313%. Thus, free CEO and MEO demonstrate bacteriostatic and bactericidal potential. We generated polymeric nanocapsules containing MEO or CEO and evaluated their efficacy at reducing biofilms formed by S. aureus. Glass and polypropylene spheres were used as test surfaces. To compare the responses of free and encapsulated oils, strains were submitted to 10 different procedures, using free and nanoencapsulated essential oils (EOs) in vitro. We observed no biofilm reduction by MEO, free or nanoencapsulated. However, CEO nanocapsules reduced biofilm formation on glass (p=0.03) and showed a tendency to diminish biofilms on polypropylene (p=0.051). Despite nanoencapsulated CEO reducing biofilms in vitro, the formulation could be improved to modify the CEO component polarity and, including MEO, to obtain more interactions with surfaces and the biofilm matrix

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Mastitis is a common and costly disease on dairy farms, commonly caused by Staphylococcus spp. though the various species are associated with different clinical outcomes. In the current study, we performed genomic analyses to determine the prevalence of adhesion, biofilm, and related regulatory genes in 478 staphylococcal species isolated from clinical and subclinical mastitis cases deposited in public databases. The most prevalent adhesin genes (ebpS, atl, pls, sasH and sasF) were found in both clinical and subclinical isolates. However, the ebpS gene was absent in subclinical isolates of Staphylococcus arlettae, S. succinus, S. sciuri, S. equorun, S. galinarum, and S. saprophyticus. In contrast, the coa, eap, emp, efb, and vWbp genes were present more frequently in clinical (vs. subclincal) mastitis isolates and were highly correlated with the presence of the biofim operon (icaABCD) and its transcriptional regulator, icaR. Co-phylogenetic analyses suggested that many of these adhesins, biofilm, and associated regulatory genes could have been horizontally disseminated between clinical and subclinical isolates. Our results further suggest that several adhesins, biofilm, and related regulatory genes, which have been overlooked in previous studies, may be of use for virulence profiling of mastitis-related Staphylococcus strains or as potential targets for vaccine development.

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BACKGROUNDS: The present study explored the viability of bovine milk macrophages, their intracellular production of reactive oxygen and nitrogen species (RONS), and their phagocytosis of Staphylococcus aureus, as well as the profile of lymphocytes, from healthy udder quarters and udder quarters infected by Corynebacterium bovis. The study included 28 healthy udder quarters from 12 dairy cows and 20 udder quarters infected by C. bovis from 10 dairy cows. The percentages of macrophages and lymphocytes were identified by flow cytometry using monoclonal antibodies. Macrophage viability, RONS production, and S. aureus phagocytosis were evaluated by flow cytometry. RESULTS: Milk samples from quarters infected with C. bovis showed a lower percentage of macrophages but an increased number of milk macrophages per mL and a higher percentage of macrophages that produced intracellular RONS and phagocytosed S. aureus. No effect of C. bovis infection on macrophage viability was found. Udder quarters infected by C. bovis showed a higher percentage of T cells and CD4+ T lymphocytes, but no effect was found on the percentage of CD8+ CD4- T, CD8- CD4- T, or B lymphocytes. CONCLUSIONS: Thus, our results corroborate, at least in part, the finding that intramammary infections by C. bovis may offer protection against intramammary infections by major pathogens.

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Bovine mastitis is an inflammation of the mammary gland, which could be the result of allergy, physical trauma, or invasion by pathogens as Streptococcus uberis. This pathogen is an environmental pathogen associated with subclinical and clinical intramammary infection (IMI) in both lactating and non-lactating cows, which can persist in the udder and cause a chronic infection in the mammary gland. In spite of the important economic losses and increased prevalence caused by S. uberis mastitis, virulence factors involved in bacterial colonization of mammary glands and the pathogenic mechanisms are not yet clear. In the last 30 years, several studies have defined adherence and internalization of S. uberis as the early stages in IMI. S. uberis adheres to and invades into mammary gland cells, and this ability has been observed in in vitro assays. Until now, these abilities have not been determined in vivo challenges since they have been difficult to study. Bacterial surface proteins are able to bind to extracellular matrix protein components such as fibronectin, collagen and laminin, as well as proteins in milk. These proteins play a role in adhesion to host cells and have been denominated microbial surface components recognizing adhesive matrix molecules (MSCRAMMs). This article aims to summarize our current knowledge on the most relevant properties of the potential factors involved in the early pathogenesis of S. uberis mastitis.

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This research aimed to investigate the genotypic relatedness of 18 Staphylococcus aureus strains isolated from intramammary infections in primiparous cows and extramammary sites on five dairy herds by rep-PCR using RW3A primers, and by PFGE using the endonuclease SmaI. The isolates were also evaluated in vitro for the susceptibility against beta-lactam antimicrobials drugs (penicillin and oxacillin), considering that beta-lactams are frequently used for treating staphylococcal intrammamary infections. The rep-PCR typing was highly discriminatory (D value= 0.9804) and a total of 15 patterns were detected. The PFGE method was also highly discriminatory (D value= 0.9667) and a total of 13 patterns were observed. A total of 15 out of 18 (83%) isolates were resistant to penicillin and one out of 18 (6%) to oxacillin. In conclusion, these findings confirmed the occurrence of a high genetic diversity of S. aureus strains at the herds and the presence of clonally-related strains only at the same herd, emphasizing a variety of genotypic profiles among the isolates.(AU)

Objetivou-se com este estudo investigar a correlação genética de 18 cepas de Staphylococcus aureus isoladas de infecções intramamárias em vacas primíparas e de locais extramamários em cinco propriedades leiteiras através das técnicas de PCR por sequências palindrômicas extragênicas repetitivas (rep-PCR), usando iniciadores RW3A, e de eletroforese em gel de campo pulsado (PFGE), usando a endonuclease SmaI. Os isolados também foram avaliados in vitro quanto à suscetibilidade aos antimicrobianos beta-lactâmicos (penicilina e oxacilina). A tipagem por rep-PCR foi altamente discriminatória (valor D = 0,9804) e um total de 15 padrões foram detectados. Os isolados de S. aureus foram agrupados em três grupos diferentes (A a C), com 80% de similaridade. A técnica de PFGE também foi altamente discriminatória (valor D = 0,9667) e um total de 13 padrões foi observado. A análise do dendrograma com um coeficiente de similaridade de 80% gerou dois grupos diferentes (A e B). Além disso, cepas clonais isoladas do leite foram identificadas na mesma propriedade pelos dois métodos de tipificação e, apesar da presença de cepas dominantes, nossos resultados sugerem uma alta diversidade genética dentre as cepas de S. aureus analisadas. Um total de 15, dos 18 (83%) isolados, eram resistentes à penicilina e um dos 18 (6%) à oxacilina. Assim, esses achados confirmam a ocorrência de uma alta diversidade genética de cepas de S. aureus nas propriedades e a presença de cepas clonalmente relacionadas apenas na mesma propriedade, enfatizando uma variedade de perfis genotípicos entre os isolados.(AU)

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Biocides and/or antibiotics used in subinhibitory concentrations can promote the development of adaptive resistance or even cross-resistance in microorganisms. However, studies on these responses following silver treatments are scarce in the literature. Silver-based compounds, including silver nanoparticles (Ag-NPs), can be an alternative in the prevention and treatment of bovine mastitis. Thus, this research evaluated the effect of subinhibitory dosages of Ag-NPs and Ag+ ions from silver nitrate (AgNO3) on Staphylococcus aureus and Escherichia coli isolated from milk of cows with mastitis. Ag-NPs were synthesized by chemical reduction using AgNO3 and sodium citrate and the minimum inhibitory concentration (MIC) of Ag-NPs and Ag+ ions on the mastitis pathogens were determined. Isolates were exposed to subinhibitory concentrations of Ag-NPs or AgNO3 for 10 consecutive days to verify the development of adaptive resistance evaluated by changes in the MIC values. The development of cross-resistance with antibiotics was also studied, being verified by comparing the sensitivity profile of treated cells with non-treated cells. AgNO3 was more effective against all isolates. There was no change in the MIC values or in the antibiotic sensitivity profile for both bacteria following consecutive exposure to subinhibitory dosages of Ag-NPs or AgNO3, indicating that silver was not able to select adaptive resistance or cross resistance to the tested antibiotics. The potential of silver presented by these results is favorable to the continuity of studies aiming to elaborate silver-based therapies for the treatment of bovine mastitis.(AU)

Biocidas e/ou antibióticos em concentrações sub-inibitórias podem promover o desenvolvimento de resistência adaptativa ou mesmo resistência cruzada nos micro-organismos. Entretanto, estudos destas respostas após o tratamento com a prata são escassos na literatura. Compostos a base de prata, incluindo as nanopartículas de prata (Ag-NPs), podem ser uma alternativa na prevenção e/ou tratamento de mastite bovina. Assim, este trabalho objetivou determinar o efeito de doses sub-inibitórias de Ag-NPs e dos íons Ag+ provenientes do nitrato de prata (AgNO3) sobre isolados de Staphylococcus aureus e de Escherichia coli, provenientes de leite de vacas com mastite. As Ag-NPs foram sintetizadas por redução química utilizando AgNO3 e citrato de sódio e a Concentração Mínima Inibitória (CMI) das Ag-NPs e íons Ag+ nos patógenos da mastite foi determinada. Os isolados foram expostos a concentrações sub-inibitórias de Ag-NPs ou de AgNO3 por 10 dias consecutivos para verificar o desenvolvimento de resistência adaptativa à prata pela mudança no valor da CMI, e de resistência cruzada com antibióticos pela mudança no perfil de sensibilidade em relação ao controle. AgNO3 apresentou-se mais efetivo contra todos os isolados. Não foi verificada alteração no valor da CMI nem do perfil de sensibilidade aos antibióticos, indicando que não houve seleção de resistência adaptativa à prata e de resistência cruzada aos antibióticos pelos micro-organismos estudados. O uso potencial da prata apresentado nos resultados é favorável à continuidade dos estudos objetivando a elaboração de terapias à base de prata para o tratamento da mastite bovina.(AU)

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Biocides and/or antibiotics used in subinhibitory concentrations can promote the development of adaptive resistance or even cross-resistance in microorganisms. However, studies on these responses following silver treatments are scarce in the literature. Silver-based compounds, including silver nanoparticles (Ag-NPs), can be an alternative in the prevention and treatment of bovine mastitis. Thus, this research evaluated the effect of subinhibitory dosages of Ag-NPs and Ag+ ions from silver nitrate (AgNO3) on Staphylococcus aureus and Escherichia coli isolated from milk of cows with mastitis. Ag-NPs were synthesized by chemical reduction using AgNO3 and sodium citrate and the minimum inhibitory concentration (MIC) of Ag-NPs and Ag+ ions on the mastitis pathogens were determined. Isolates were exposed to subinhibitory concentrations of Ag-NPs or AgNO3 for 10 consecutive days to verify the development of adaptive resistance evaluated by changes in the MIC values. The development of cross-resistance with antibiotics was also studied, being verified by comparing the sensitivity profile of treated cells with non-treated cells. AgNO3 was more effective against all isolates. There was no change in the MIC values or in the antibiotic sensitivity profile for both bacteria following consecutive exposure to subinhibitory dosages of Ag-NPs or AgNO3, indicating that silver was not able to select adaptive resistance or cross resistance to the tested antibiotics. The potential of silver presented by these results is favorable to the continuity of studies aiming to elaborate silver-based therapies for the treatment of bovine mastitis.

Biocidas e/ou antibióticos em concentrações sub-inibitórias podem promover o desenvolvimento de resistência adaptativa ou mesmo resistência cruzada nos micro-organismos. Entretanto, estudos destas respostas após o tratamento com a prata são escassos na literatura. Compostos a base de prata, incluindo as nanopartículas de prata (Ag-NPs), podem ser uma alternativa na prevenção e/ou tratamento de mastite bovina. Assim, este trabalho objetivou determinar o efeito de doses sub-inibitórias de Ag-NPs e dos íons Ag+ provenientes do nitrato de prata (AgNO3) sobre isolados de Staphylococcus aureus e de Escherichia coli, provenientes de leite de vacas com mastite. As Ag-NPs foram sintetizadas por redução química utilizando AgNO3 e citrato de sódio e a Concentração Mínima Inibitória (CMI) das Ag-NPs e íons Ag+ nos patógenos da mastite foi determinada. Os isolados foram expostos a concentrações sub-inibitórias de Ag-NPs ou de AgNO3 por 10 dias consecutivos para verificar o desenvolvimento de resistência adaptativa à prata pela mudança no valor da CMI, e de resistência cruzada com antibióticos pela mudança no perfil de sensibilidade em relação ao controle. AgNO3 apresentou-se mais efetivo contra todos os isolados. Não foi verificada alteração no valor da CMI nem do perfil de sensibilidade aos antibióticos, indicando que não houve seleção de resistência adaptativa à prata e de resistência cruzada aos antibióticos pelos micro-organismos estudados. O uso potencial da prata apresentado nos resultados é favorável à continuidade dos estudos objetivando a elaboração de terapias à base de prata para o tratamento da mastite bovina.

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Mastitis is a mammary gland inflammation that is very common worldwide, mostly caused by bacteria, and causes enormous economic losses. Many microorganisms cause this disease. The most common causes of mastitis by these microorganisms are Staphylococcus aureus (S. aureus), Escherichia coli (E. coli) and Streptococcus agalactiae (S. agalactiae). The anti-inflammatory properties of transforming growth factor (TGF)-ß include: 1) limiting interferon (IFN)-γ production; 2) increasing the expression of the interleukine (IL)-1 receptor antagonist; 3) inhibiting macrophage production of chemokines, pro-inflammatory cytokines, nitric oxide, and reactive oxygen intermediates; and 4) increasing macrophage clearance of bacterial debris and damaged parenchymal cells. It is stated that cytokines and milk composition change in case of mastitis. In this study, it was aimed to reveal the changes in milk TGF-ß1 and Tumor necrosis factor (TNF)-α concentrations and milk composition in mixed infections caused by three pathogens causing mastitis. In this study, milk samples from 90 cows were divided into 5 groups. Tumor necrosis factor (TNF)-α and TGF-ß1 concentrations and milk composition were determined in these milk samples. The California Mastitis Test (CMT) was applied to the cows included in the study and scoring was done. According to the CMT results of the milk samples taken, CMT(-) cows were included in group 1 (n = 22). Those with the CMT(+) were sent to the microbiology laboratory for analysis within 2 h. After the bacteria was determined, combination groupings were formed. Group 2 (n = 17), in which S. aureus and E. coli grew together, group 3 (n = 21), in which S. aureus and S. agalactiae grew together, group 4 (n = 8), in which S. agalactiae and E. coli grew together in milk samples, and milk samples without any bacterial growth in CMT (+) formed group 5 (n = 22), respectively. Somatic cell count was measured with the DeLaval Cell Counter® (Cell Counter DCC) device. Mineral matter, fat, protein, lactose, electrical conductivity and specific gravity were measured in milk samples using Lactoscan Milk Analyzer (Milkotronic/EUROPE). Milk samples were then stored at -80°C to measure TGF-ß1 and TNF-α. Tumor necrosis factor-α and TGF-ß1 concentrations in milk samples were measured using ELISA kits (Sunred Biological Technology). Changes in milk TNF-α and TGF-ß1 concentration and milk composition were determined in milk samples with mastitis caused by mixed infection. The TNF-α concentration of group 4 was higher than the other groups. On the other hand, the highest concentration of TGF-ß1 was found in group 2. While the number of somatic cells in group 1 was lower than in groups 2, 3, and 4, there was no statistical difference between groups 1 and 5. The lowest milk fat ratio was found in group 1, and it was found to be statistically lower than groups 2, 3, and 4. While the rate of solid-non-fat of group 1 increased compared to groups 2 and 3, the highest protein ratio was found in groups 1 and 5. There was no difference between the 5 groups in terms of mineral matter ratios. While the specific gravity was highest in group 1, there was no statistical difference between the other 4 groups. Overall, it was concluded that there was an increase in TNF-α and TGF-ß1 concentrations and a change in milk composition in samples with bacterial growth.(AU)

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We evaluated the effects of chronic subclinical mastitis (CSM) caused by different types of pathogens on milk yield and milk components at the cow level. A total of 388 Holstein cows had milk yield measured and were milk sampled three times at intervals of two weeks for determination of SCC and milk composition, and microbiological culture was performed. Cows were considered healthy if all three samples of SCC were ≤200 000 cells/ml and were culture-negative at the third milk sampling. Cows with one result of SCC > 200 000 cells/ml were considered to suffer non-chronic subclinical mastitis whereas cows with at least 2 out of 3 results of SCC > 200 000 cells/ml had CSM. These latter cows were further sorted according to culture results into chronic negative-culture or chronic positive-culture. This resulted in four udder health statuses: healthy, non-chronic, chronicNC or chronicPC. The milk and components yields were evaluated according to the udder health status and by pathogen using a linear mixed effects model. A total of 134 out of 388 cows (34.5%) were chronicPC, 57 cows (14.7%) were chronicNC, 78 cows (20.1%) were non-chronic and 119 cows (30.7%) were considered healthy, which resulted in a grand total of 1164 cow records included in the statistical model. The healthy cows produced more milk than each of the other groups (+2.1 to +5.7 kg/cow/day) and produced higher milk component yields than the chronicPC cows. The healthy cows produced more milk than cows with chronicPC caused by minor (+5.2 kg/cow/day) and major pathogens (+7.1 kg/cow/day) and losses varied from 5.8 to 11.8 kg/cow/day depending on the pathogen causing chronicPC mastitis. Chronic positive-culture cows had a reduction of at least 24.5% of milk yield and 22.4% of total solids yield.

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Although, antibiotics are effective in the treatment of bovine mastitis, they do not address the regeneration of mammary glandular tissue and have been associated to the increment in antimicrobial resistance worldwide. Considering the necessity of alternative therapies for this disease of high economic impact and the reported regenerative and antibacterial effects of mesenchymal stem cell (MSCs), we evaluated the safety and efficacy of an allogenic MSC-based intramammary therapy in dairy cows with experimentally induced Staphylococcus aureus clinical mastitis. In a safety trial, heifers were inoculated intramammarily with a 2.5 × 107-suspension of bovine fetal AT-MSCs on experimental days 1 and 10. Animals were evaluated clinically on a daily basis during a 20-day experimental period and blood samples were collected for hemogram determination and peripheral blood leukocytes (PBLs) isolation. In an efficacy trial, Holstein Friesian cows were inoculated with S. aureus and treated intramammarily with vehicle (NEG; days 4 and 10), antibiotics (ATB; days 4 and 5) or a suspension of 2.5 × 107 AT-MSCs (MSC; days 4 and 5). Cows were clinically evaluated daily and milk samples were collected for somatic cell count (SCC) and colony forming units (CFU). Blood samples were collected for serum haptoglobin and amyloid A determination. Intramammary administration of two doses of bovine fetal AT-MSCs in healthy cows did not induce changes in clinical or hematological variables, and gene expression profiles in PBLs associated to activation (CD4, CD8, CD25, CD62L and CD69) and proinflammatory cytokines (CCL2, CCL5, IL2, CXCL3, IFNγ, and TNFα). Quarters of MSC group of cows had similar SCC log/mL in milk compared to infected quarters of ATB or NEG cows. However, quarters of MSC cows had lower CFU log/mL in milk compared to quarters of NEG cows. Intramammarily inoculation of repeated doses of 2.5 × 107 allogenic AT-MSCs did not induce clinical or immunological response in healthy cows. Moreover, MSC-intramammary treatment reduced bacterial count in milk of cows with S. aureus clinical mastitis compared to untreated cows. This work provides initial evidence for the safety and efficacy of an allogenic MSC-based intramammary therapy for the treatment of bovine mastitis.

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Mesenchymal stem cells have been widely used in the treatment of various chronic diseases. The objective of this survey was to evaluate the therapeutic and regenerative potential of stem cells from adipose tissue (ASCs) in the milk production recovery repair of tissue injury in mastitis goats treated with antimicrobial agents prior to cell therapy. After the diagnosis of mastitis and treatment with gentamicin, eight lactating goats were selected for cellular and subsequent therapy, physical-chemical analysis of milk, ultrasonographic and histopathological examinations. The ASCs were taken from the subcutaneous fat of a young goat cultivated in vitro, marked with Qdots-655 and injected in the left mammary gland, being the right mammary gland used as the control. After 30 days the ultrasonographic and histopathological analyzes were repeated and, in the first lactation period, the physical-chemical analysis of the milk was reapeated. Before the cellular therapy, the physical-chemical quality of the milk was compromised and the ultrasonographic and histopathological analysis revealed a chronic inflammatory process and fibrous tissue. The marking of the ASCs with Qdots enabled the tracking, by fluorescence microscopy (BX41-OLYMPUS), in the mammary tissue. In the ASCs therapy, cultures showed high cellularity and characteristics favorable to preclinical studies; with the therapy the physical-chemical parameters of the milk, fat, protein, temperature and pH showed significant differences among the groups; five animals treated with ASCs reconstituted the functionality of the gland and the connective tissue reduced in quantity and inflammatory infiltrate cells. ASCs have potential for the possible regeneration of fibrous mastitis lesions in the mammary gland, however, it would be necessary to increase injection time for the histopathological analysis, since the reconstitution of the glandular acini within the assessed period was not finalized. ASCs can be used to reestablish milk production in goat with chronic mastitis repair mammary lesions, with potential to be a promising clinical alternative for animal rehabilitation for productivity.

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O objetivo do presente estudo foi avaliar a capacidade de estafilococos não aureus (NAS) isolados de diferentes nichos ecológicos (leite, ambiente e ápice do teto), associados a vacas leiteiras, de inibir os principais agentes etiológicos da mastite bovina (Staphylococcus aureus, Streptococcus agalactiae, Streptococcus uberis e Escherichia coli). Neste estudo, 38 isolados NAS de diferentes nichos ecológicos foram avaliados quanto à capacidade de inibir o crescimento in vitro de importantes patógenos causadores de mastite pelo método cross-streaking. No total, 19 (50%) isolados de NAS (oito isolados de S. chromogenes, 10 de S. fleurettii e um de S. haemolyticus) apresentaram inibição contra os principais patógenos causadores de mastite. No entanto, a inibição dos patógenos causadores da mastite bovina por isolados de NAS foi maior contra bactérias Gram-positivas. Além disso, o presente estudo não sugeriu que os nichos ecológicos influenciam a capacidade do NAS de inibir os principais patógenos causadores da mastite bovina. Com base nesses resultados, concluiu-se que certos isolados de NAS apresentam potencial efeito protetor contra os principais patógenos da mastite, pelo menos in vitro.(AU)

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O objetivo do presente estudo foi avaliar a capacidade de estafilococos não aureus (NAS) isolados de diferentes nichos ecológicos (leite, ambiente e ápice do teto), associados a vacas leiteiras, de inibir os principais agentes etiológicos da mastite bovina (Staphylococcus aureus, Streptococcus agalactiae, Streptococcus uberis e Escherichia coli). Neste estudo, 38 isolados NAS de diferentes nichos ecológicos foram avaliados quanto à capacidade de inibir o crescimento in vitro de importantes patógenos causadores de mastite pelo método cross-streaking. No total, 19 (50%) isolados de NAS (oito isolados de S. chromogenes, 10 de S. fleurettii e um de S. haemolyticus) apresentaram inibição contra os principais patógenos causadores de mastite. No entanto, a inibição dos patógenos causadores da mastite bovina por isolados de NAS foi maior contra bactérias Gram-positivas. Além disso, o presente estudo não sugeriu que os nichos ecológicos influenciam a capacidade do NAS de inibir os principais patógenos causadores da mastite bovina. Com base nesses resultados, concluiu-se que certos isolados de NAS apresentam potencial efeito protetor contra os principais patógenos da mastite, pelo menos in vitro.(AU)

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O presente trabalho objetivou relatar um caso de mastite causada por Enterobacter aerogenes no município de Primavera do Leste MT. Foi atendida em propriedade agro familiar uma vaca da raça Holandesa, de aproximadamente 8 anos de idade, apresentando sinais clínicos de edema de úbere, rubor, hiperemia e presença de secreção no leite. Diante do quadro clínico, foi coletado material intramamário por meio de um swab de transporte para identificação do agente patogênico, acrescido de antibiograma. A partir desta amostra foi possível identificar a bactéria Enterobacter aerogenes como causadora da doença, além de constatar sensibilidade a 14 dos 22 antibióticos testados. Foi detectada resistência aos fármacos Cefoxitina e Fosfomicina. A ocorrência de ESBL ocorreu nos fármacos Aztreonam e Cefotaxima. A incidência da doença é relacionada ao déficit de boas práticas de higiene, manejos inadequados e tratamentos errôneos, sendo necessária a adoção de boas práticas para prevenção da enfermidade.(AU)

The present study aimed to report a case of mastitis caused by Enterobacter aerogenes in the municipality of Primavera do Leste/MT. One Holstein cow with approximately 8 years old, was attended in the family farming. The cow showed clinical signs as udder swelling, redness, hyperemia and presence of milk secretion. In view of the clinical condition, intramammary material was collected by means of a transport swab to identify the pathogen, plus antibiogram. From this sample it was possible to identify the bacterium Enterobacter aerogenes as cause of the disease, in addition to detecting sensitivity to 14 of the 22 antibiotics tested. Resistance to the drugs Cefoxitin and Fosfomycin was detected. The occurrence of ESBL occurred in the Aztreonam and Cefotaxime drugs. The incidence of the disease is related to the deficiency of good hygiene practices, inadequate management and erroneous treatments. It is necessary to adopt good practices to prevent the disease.(AU)

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O presente trabalho objetivou relatar um caso de mastite causada por Enterobacter aerogenes no município de Primavera do Leste MT. Foi atendida em propriedade agro familiar uma vaca da raça Holandesa, de aproximadamente 8 anos de idade, apresentando sinais clínicos de edema de úbere, rubor, hiperemia e presença de secreção no leite. Diante do quadro clínico, foi coletado material intramamário por meio de um swab de transporte para identificação do agente patogênico, acrescido de antibiograma. A partir desta amostra foi possível identificar a bactéria Enterobacter aerogenes como causadora da doença, além de constatar sensibilidade a 14 dos 22 antibióticos testados. Foi detectada resistência aos fármacos Cefoxitina e Fosfomicina. A ocorrência de ESBL ocorreu nos fármacos Aztreonam e Cefotaxima. A incidência da doença é relacionada ao déficit de boas práticas de higiene, manejos inadequados e tratamentos errôneos, sendo necessária a adoção de boas práticas para prevenção da enfermidade.

The present study aimed to report a case of mastitis caused by Enterobacter aerogenes in the municipality of Primavera do Leste/MT. One Holstein cow with approximately 8 years old, was attended in the family farming. The cow showed clinical signs as udder swelling, redness, hyperemia and presence of milk secretion. In view of the clinical condition, intramammary material was collected by means of a transport swab to identify the pathogen, plus antibiogram. From this sample it was possible to identify the bacterium Enterobacter aerogenes as cause of the disease, in addition to detecting sensitivity to 14 of the 22 antibiotics tested. Resistance to the drugs Cefoxitin and Fosfomycin was detected. The occurrence of ESBL occurred in the Aztreonam and Cefotaxime drugs. The incidence of the disease is related to the deficiency of good hygiene practices, inadequate management and erroneous treatments. It is necessary to adopt good practices to prevent the disease.

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Neste trabalho, objetivou-se verificar a ocorrência de mastite em vacas sem raça definida de uma propriedade do município do Cantá. Foram avaliados onze animais, sendo os quesitos observados: escore corporal, idade, número de crias, produção leiteira, lesão de casco e, por fim, se há ou não a presença da mastite. A maioria das vacas apresentou fraca positividade para a enfermidade, sendo que apenas uma resultou em forte positivo em um dos tetos. Com isso, é possível concluir que a propriedade onde se realizou a pesquisa não positivou a mastite em seu pior grau, visto que há uma baixa produção individual das vacas e a presença do bezerro ao pé.(AU)

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Neste trabalho, objetivou-se verificar a ocorrência de mastite em vacas sem raça definida de uma propriedade do município do Cantá. Foram avaliados onze animais, sendo os quesitos observados: escore corporal, idade, número de crias, produção leiteira, lesão de casco e, por fim, se há ou não a presença da mastite. A maioria das vacas apresentou fraca positividade para a enfermidade, sendo que apenas uma resultou em forte positivo em um dos tetos. Com isso, é possível concluir que a propriedade onde se realizou a pesquisa não positivou a mastite em seu pior grau, visto que há uma baixa produção individual das vacas e a presença do bezerro ao pé.

Assuntos

RESUMO

A mastite bovina é a enfermidade que causa maior impacto na produção leiteira, sendo o microrganismo Staphylococcus aureus o mais prevalente. Este gênero possui a capacidade de produzir biofilmes que é um importante mecanismo de resistência aos antibióticos. Considerando a capacidade terapêutica das plantas, a espécie Croton urucurana, nativa do Cerrado, foi alvo do presente estudo, que teve como objetivo avaliar a atividade antibiofilme in vitro do extrato vegetal e substâncias isoladas desta espécie, frente Staphylococcus aureus, isolados de leite de vacas com mastite, bem como dos antibióticos gentamicina e vancomicina. A atividade antibiofilme foi avaliada por meio do cristal violeta e da contagem de unidades formadoras de colônia. As imagens foram obtidas por microscopia eletrônica de varredura. O extrato bruto e frações de C. urucurana apresentaram atividade antibiofilme superior à gentamicina e semelhante à vancomicina, enquanto a substância isolada α-Costol foi significativamente mais ativa quando comparada aos demais tratamentos avaliados, reduzindo cerca de 6 ciclos logarítmicos da população bacteriana em biofilme. Conclui-se que os fitocomplexos e a substância α-Costol isolados de Croton urucurana são promissores no combate a um dos principais agentes etiológicos da mastite bovina.(AU)

Mastitis in dairy cattle is the disease that impacts dairy production the most; Staphylococcus aureus is the main causative agent of this condition. The genus Staphylococcus has the ability to produce biofilms, an important mechanism of antibiotic resistance. Bearing in mind that plants have therapeutic action, this study investigated the in vitro antibiofilm activity of the plant extract and compounds isolated from the species Croton urucurana, native to the Brazilian Cerrado, against Staphylococcus aureus isolated from the milk of cows with mastitis, as well as the antibiotic gentamycin and vancomicyn. The antibiofilm activity was evaluated by means of violet crystal and the counting of Colony Forming Units. The images were obtained by scanning electron microscopy. The C. urucurana crude extract and fraction displayed better antibiofilm effect than gentamycin; their antibiofilm action was similar to the action of vancomycin. Compared with all the assessed treatments, the isolated compound α-Costol was significantly more active it reduced six logarithmic cycles of the bacterial population composing the biofilm. The phytocomplexs and the α-Costol substance isolated from Croton urucurana are promising in the fight against one of the main etiological agents of bovine mastitis.(AU)

Assuntos

RESUMO

A mastite bovina é a enfermidade que causa maior impacto na produção leiteira, sendo o microrganismo Staphylococcus aureus o mais prevalente. Este gênero possui a capacidade de produzir biofilmes que é um importante mecanismo de resistência aos antibióticos. Considerando a capacidade terapêutica das plantas, a espécie Croton urucurana, nativa do Cerrado, foi alvo do presente estudo, que teve como objetivo avaliar a atividade antibiofilme in vitro do extrato vegetal e substâncias isoladas desta espécie, frente Staphylococcus aureus, isolados de leite de vacas com mastite, bem como dos antibióticos gentamicina e vancomicina. A atividade antibiofilme foi avaliada por meio do cristal violeta e da contagem de unidades formadoras de colônia. As imagens foram obtidas por microscopia eletrônica de varredura. O extrato bruto e frações de C. urucurana apresentaram atividade antibiofilme superior à gentamicina e semelhante à vancomicina, enquanto a substância isolada α-Costol foi significativamente mais ativa quando comparada aos demais tratamentos avaliados, reduzindo cerca de 6 ciclos logarítmicos da população bacteriana em biofilme. Conclui-se que os fitocomplexos e a substância α-Costol isolados de Croton urucurana são promissores no combate a um dos principais agentes etiológicos da mastite bovina.(AU)

Mastitis in dairy cattle is the disease that impacts dairy production the most; Staphylococcus aureus is the main causative agent of this condition. The genus Staphylococcus has the ability to produce biofilms, an important mechanism of antibiotic resistance. Bearing in mind that plants have therapeutic action, this study investigated the in vitro antibiofilm activity of the plant extract and compounds isolated from the species Croton urucurana, native to the Brazilian Cerrado, against Staphylococcus aureus isolated from the milk of cows with mastitis, as well as the antibiotic gentamycin and vancomicyn. The antibiofilm activity was evaluated by means of violet crystal and the counting of Colony Forming Units. The images were obtained by scanning electron microscopy. The C. urucurana crude extract and fraction displayed better antibiofilm effect than gentamycin; their antibiofilm action was similar to the action of vancomycin. Compared with all the assessed treatments, the isolated compound α-Costol was significantly more active it reduced six logarithmic cycles of the bacterial population composing the biofilm. The phytocomplexs and the α-Costol substance isolated from Croton urucurana are promising in the fight against one of the main etiological agents of bovine mastitis.(AU)

Assuntos

RESUMO

Dairy farming is an important social and economic activity in the Midwest region of Santa Catarina State, Brazil. However, despite technological advances in the productive chain, mastitis is still considered the main disease of dairy herds, due its high economic impact. Bacterial pathogens are the main cause of this disease and failures in the treatment of clinical cases are attributed in part to the antimicrobial resistance of these pathogens. As an alternative, in vitro antimicrobial susceptibility tests of strains isolated from bovine mastitis cases have been carried out; the information generated contributes to strategic treatment measures, and also to the control of microorganism resistance. Therefore, the aims of the present study were to evaluate the etiology and in vitro antimicrobial susceptibility profiles of bacterial strains isolated from cases of bovine mastitis in dairy herds from the Midwest region of Santa Catarina State, Brazil. For this purpose, 345 milk samples were collected from 70 herds located in 16 different municipalities. The main pathogens isolated were: staphylococci (55.9%), streptococci (34.8%), Corynebacterium spp. (7.8%) and Escherichia coli (1.4%). The resistance rates of staphylococcus strains to ampicillin and to gentamicin were lower (24.9%) and higher (33%), respectively, than those obtained in other Brazilian studies. The resistance profiles of streptococcus strains were similar to those described in the literature, while Corynebacterium spp., showed high resistance rates to tetracycline (85.2%). Moreover, a considerable prevalence of staphylococcus (27.5%) and streptococcus (11.7%) multiresistant strains was verified. These data reinforce the need for regional characterization of microorganisms.(AU)

Assuntos