95 research outputs found

    OCORRÊNCIA DE BOTULISMO EM BOVINOS CONFINADOS NO RIO GRANDE DO SUL

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    Botulismo é a intoxicação causada pela neurotoxina produzida pelo Clostridium botulinum, caracterizando-se por paralisia flácida ou completa da musculatura esquelética. Este trabalho relata um surto de botulismo em bovinos confinados, alimentados com silagem de milho. Amostras de fígado, conteúdo intestinal e ruminal de um dos bovinos com o quadro clínico característico de botulismo e uma porção da silagem de milho foram encaminhados para análise bacteriológica. No laboratório realizaram-se bioensaio em camundongos e soroneutralização, sendo confirmada a suspeita de botulismo tipo C. Este relato visa alertar médicos veterinários e criadores que adotam o confinamento de animais, pois esta prática de manejo aumenta a suscetibilidade ao botulismo, principalmente relacionada ao tipo e qualidade do alimento consumido. PALAVRAS CHAVE: Bovinos, Clostridium botulinum, confinamento

    Phenotypic and Genotypic Characteristics and Resistance Profile of Staphylococcus spp. from Bovine Mastitis

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    Background: Bovine mastitis remains one of the health problems that cause the most damage to milk producers. The negative impact of mastitis is due to reduced milk production, early slaughter of females, reduced commercial value of the affected animals, losses in the genetic potential of the herd, expenses with medicines and veterinary medical assistance. Staphylococcus spp. stands out as the cause of this disease and has been able to remain in the mammary gland, becoming resistant to several antimicrobials. The aims of the present study were to characterize the phenotypes, genotypes and resistance profiles of Staphylococcus spp. isolates from bovine mastitis cases in the state of Pernambuco, Brazil.Materials, Methods & Results: These isolates were classified according to biochemical tests and the presence of the nuc gene.  The polymerase chain reaction (PCR) for amplification of the mecA and blaZ genes was used to analyze the genetic potentials of antimicrobial resistance. Isolates were also phenotypically tested for resistance to nine antimicrobials (ampicillin, doxicillin, erythromycin, gentamicin, rifampicin, cephalothin, amoxicillin, nalidixic acid and oxacillin). The genetic potentials for biofilm production were evaluated by the amplifications of the icaD, icaA and bap genes. The phenotypic test of gentian violet was used for biofilm formation analyzes. Ninety-three (93.0%) of the isolates among the Staphylococcus spp. samples were classified as Staphylococcus aureus. The lowest percentage of sensitivity observed was for amoxicillin (28.0%). All of the isolates were sensitive to erythromycin and gentamicin, and 15 (15%) exhibited sensitivity to all of the drugs tested. All of the isolates were negative for the mecA gene, and 36 (36%) were positive for blaZ. In the adhesion microplate tests, 44 (44%) of the isolates were capable of biofilm formation. Of these, seven (15.9%) were strong formers, whereas 16 (36.3%) and 21 (47.8%) were moderate and weak formers, respectively. The icaD gene was confirmed in 89 (89%) of the isolates. The icaA gene was confirmed in 61 (61%) samples, and the bap gene in 52 (52%) samples. One of the samples did not possess icaA, icaD or bap and exhibited moderate biofilm formation according to the microplate adherence test. Sixteen isolates simultaneously exhibited the three genes tested for biofilm production (icaA, icaD and bap) and were negative according to the microplate adherence test.Discussion:  The indiscriminate use of antibiotics to treat mastitis is a common practice in the study area, which may have contributed to the high proportion of herds (88.23%; 15/17) with multi-resistant isolates, constituting a selection factor for the dissemination of resistant bacteria among herds.  The absence of the mecA gene in the present study may be associated with the development of resistant bacteria through another mechanism, such as the overproduction of beta-lactamases. The results demonstrate that antimicrobial resistance occurs in Staphylococcus spp. that cause bovine mastitis in herds of Pernambuco and that these isolates have the a great capacity for biofilm formation. It is necessary to sensitize the professionals involved in the milk production chain of Brazil regarding the importance of the adequate use of antimicrobials for the treatment and control of mastitis, since studies in the country indicate the dissemination of resistant bacterial strains

    Virulence Factors in Staphylococcus aureus and Quality of Raw Milk from Dairy Cows in a Semiarid Region of Northeastern Brazil

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    Background: Milk quality is considered unsatisfactory in Brazil due to factors of a social, economic, cultural, and climatic nature. Mastitis is the main disease that affects dairy herds. Microorganisms of the genus Staphylococcus are the most frequently isolated pathogens in cases of mastitis in bovines. Staphylococcus aureus requires more attention because they have the ability to develop resistance to antimicrobials used in the treatment of mastitis. Thus, the aim of the present study was to evaluate virulence factors in isolates of S. aureus as well as analyze the hygienic-sanitary quality of raw milk produced on dairy farms in a semiarid region of northeastern Brazil.Material, Methods & Results: Samples were taken from milk containers at 44 properties. Fifty-eight isolates of Staphylococcus spp. were analyzed and genotypically identified as S. aureus. In the phenotypic characterization, 56.8% (33/58) of the isolates demonstrated moderate biofilm production. In the genotypic characterization (icaA, icaD and bap genes), icaA was the most representative among the isolates. No resistance to cephalothin or oxacillin was found, but 62% (36/58) of the isolates exhibited resistance to ampicillin, amoxicillin, and penicillin. In the genotypic evaluation in response to β-lactam antibiotics, 50% (29/58) of the isolates exhibited the blaZ gene. Total bacterial counts were determined based on the standard plate count and flow cytometry, for which a significant positive correlation was found (r = 0.61, P < 0.01). The somatic cell count was also performed using flow cytometry and demonstrated that 6.8% (3/44) of the properties had values above one million cells per mL. The analysis of Staphylococcus spp. revealed that 20% (9/44) of the properties had significant counts for the production of staphylococcal enterotoxins. Regarding total coliforms, 56.8% (25/44) of the milk analyzed had counts above 1.0 x 103 CFUs/mL. There were no cases of the isolation of Pseudomonas spp. Streptococcus spp. was isolated on 6.8% (3/44) of the properties. The results of the sequencing revealed one isolate to be Lactococcus lactis and two to be Enterococcus spp.Discussion: None of the 58 isolates of S. aureus was classified as negative in the phenotypic characterization of biofilmforming capacity, which suggests the presence of genes involved in this process. Studies have shown that the molecular techniques used to identify ica genes encoding biofilm synthesis are very important for the identification of virulent strains. The isolates demonstrated resistance to β-lactam antibiotics of the class of penicillins, which are the most widely employed antimicrobial agents for the treatment of diseases in dairy herds. The presence of the blaZ gene in 50% of the isolates is in agreement with data reported in other studies developed in northeastern Brazil. In 50% (29/58) of the isolates, the presence of the blaZ gene was not observed. Of these, (8/29) were resistant to ampicillin, amoxicillin and penicillin. This is due to the existence of other bacterial mechanisms. Research has shown that some isolates possessed three mechanisms (blaZ, mecA and msrA) of antimicrobial resistance simultaneously. The results of the quality analyses demonstrate that some properties produce milk of low quality, which underscores the need for management strategies directed at reducing the contamination of the product

    Antimicrobial activity of silver nanoparticles synthesized by the fungus Curvularia inaequalis

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    Silver nanoparticles have been widely reported in literature due to their vast industrial application in different areas. In this work, we explored a simple procedure for the biosynthesis of silver nanoparticles at room temperature from the action of Curvularia inaequalis as reduction agent. The degree of aggregation and size of biosynthesized particles were optimized from a factorial design involving combined variation of three different parameters of preparation. The resulting colloidal dispersion of silver nanoparticles presented strong antimicrobial activity against Escherichia coli and Klebsiella pneumoniae in an indication that C. inaequalis represents a new potential candidate for alternative biosynthesis of silver nanoparticles with antimicrobial activity.Keywords: Antimicrobial activity, fungi, silver nanoparticlesAfrican Journal of Biotechnology Vol. 12(20), pp. 2917-292

    Protective Properties in Hymenaea martiana Hayne against Multi-drug-resistant Staphylococcus aureus

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    Antibiotic resistance represents a widespread problem in milk production. The identification of compounds for a topically applied ointment used in mastitis therapy remains elusive. Compounds from the genus Hymenaea can be administered in cases of multi-drug-resistant Staphylococcus aureus infection for ruminant species, but the protective properties are not well known. Wi this research the aim is verify the protective effects of H. martiana against S. aureus infection in bovine mammary epithelial cell line (MAC-T) and to obtain an antioxidant profile evaluation in vitro. The MAC-T cells were challenged with S. aureus after being exposed to the extract of the H. martiana in the protective assay. For the verification of the viability of the MAC-T cells, the MTT assay was performed, and was used dilutions of the plant extract, starting at 2.5%. The extract of H. martiana was evaluated for antioxidant aspect in different dilutions by FRAP, ORAC and DPPH. A variety of flavonoids (quercetin, luteolin, etc.) have been identified as the main components by using mass spectrometry, reinforcing our in vitro findings that flavonoids, especially quercetin, have a medicinal profile capable of killing mastitis-causing bacteria. An excellent antioxidant pattern was observed in the 2.5% solution; however, membrane integrity in MAC-T cells was compromised. Those findings suggest low dilutions of H. martiana extract has a desirable protective effect from S. aureus pathogenesis. Our in vitro studies can be gleaned upon for further in vivo studies

    Formigas (Hymenoptera: Formicidae) como vetores na transmissão de Staphylococcus aureus em um hospital público

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    Objetivo: analisar o potencial de formigas como veículos mecânicos de bactérias do gênero Staphylococcus aureus no centro cirúrgico e unidade de terapia intensiva de um hospital público. Metodologia: trata-se de um estudo descritivo. As formigas foram coletadas utilizando-se iscas atrativas que ficavam expostas por três horas sendo, após a exposição, incubadas por 24h a 35ºC. A susceptibilidade aos antimicrobianos foi analisada através da técnica de disco-difusão. Os isolados de Cocos gram-positivos foram submetidos a Reação em Cadeia da Polimerase e observado os genes nuc, mecA blaZ e icaAD. Resultados: foram coletadas 592 formigas pertencentes à espécie Tapinoma melanocephalum e Pheidole sp. Todos os isolados apresentaram o gene mecA, 93,7% apresentaram resultado positivo para o gene blaZ e 12,5% para o gene icaA e icaD. Sete isolados apresentaram multirresistência. Conclusão: os resultados sugerem que as formigas podem agir como veiculadoras de bactérias multirresistentes no ambiente hospitalar. Abstract Objective: to analyze the potential of ants as mechanical vehicles of bacteria of the genus Staphylococcus Aureus in the surgical center and intensive care unit of a public hospital. Methodology: this was a descriptive study. The ants were collected using attractive baits that were exposed for three hours and, after exposure, incubated for 24 hours at 35ºC. The susceptibility to antimicrobials was analyzed using the disk-diffusion technique. Gram-positive Cocos isolates were subjected to Polymerase Chain Reaction and the nuc, mecA blaZ and icaAD genes were observed. Results: 592 ants belonging to the species Tapinoma melanocephalum and Pheidole sp. All isolates showed the mecA gene, 93.7% were positive for the blaZ gene and 12.5% for the icaA and icaD gene. Seven isolates showed multidrug resistance. Conclusion: the results suggest that ants can act as carriers of multidrug-resistant bacteria in the hospital environment
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