Saúde e Segurança Alimentar: Isolamento e análise do perfil de suscetibilidade de bactérias patogênicas de alimentos

Background and Objectives: Currently there is a growing concern about the sanitary conditions of food products made available to population, as there is a wide range of pathogens associated with food contamination. The purpose of this study was to isolation and susceptibility profile analysis of Escherichia coli, Salmonella spp. and Staphylococcus positive coagulase from ground beef samples collected in commerce of Pelotas city, Rio Grande do Sul, Brazil. Methods: For bacterial isolation were utilized 20 samples of ground beef originating in local commerce, being performed the research for E. coli, Salmonella spp. and S. coagulase positive. Any bacterial strains isolated were submitted to analysis of the susceptibility profile, where ten different antibiotics have been tested. Results: The susceptibility profile ranging among isolates in Salmonella spp., we observed the higher rate multidrug resistance, 58% of these were resistant to multiple antibiotics. In isolates of Escherichia coli occurred 44.4% of multidrug resistance. Strains of Staphylococcus positive coagulase showed the lowest rate, 25% of these have been multiresistant, and all isolates were sensitive to oxacillin. Conclusions: The high contamination of samples of ground beef highlights the need for a good hygiene practices and transport animal products. Resistance and multiresistance levels to the antibiotics tested, may demonstrate a possible inappropriate use of antimicrobials in veterinary medicine.Justificativa e Objetivos: Atualmente é crescente a preocupação com as condições higiênicosanitárias de produtos alimentícios disponibilizados a população, visto que há uma grande diversidade de patógenos associados com a contaminação de alimentos. Com isso o objetivo do presente estudo foi o isolamento e a análise do perfil de suscetibilidade de Escherichia coli, Salmonella spp. e Staphylococcus coagulase positiva provenientes de amostras de carne moída obtidas no comércio da cidade de Pelotas, Rio Grande do Sul, Brasil. Métodos: Para o isolamento bacteriano foram utilizadas 20 amostras de carne moída originárias do comércio local, sendo realizada a pesquisa para E. coli, Salmonella spp. e S. coagulase positiva. Todas as cepas bacterianas isoladas foram submetidas a análise do perfil de suscetibilidade, onde foram testados dez diferentes antibióticos. Resultados: O perfil de suscetibilidade variou entre os isolados, em Salmonella spp. observou-se a maior taxa de multirresistência, 58% destas foram resistentes a múltiplos antibióticos, e para os isolados de E. coli ocorreu 44,4% de multirresistência. As cepas de S. coagulase positiva apresentaram a menor taxa, 25% destas foram multiresistentes, e todos os isolados foram sensíveis a oxacilina. Conclusões: A elevada contaminação das amostras de carne moída evidencia a necessidade de boas práticas de higiene e transporte de produtos de origem animal. Quanto aos níveis de resistência e multirresistência aos antibióticos testados, pode-se aferir um possível uso inadequado de antimicrobianos na rotina veterinária

<b><i>In vitro</i> study on the antimicrobial effect of hydroalcoholic extracts from <i>Mentha arvensis</i> L. (Lamiaceae) against oral pathogens</b> - doi: 10.4025/actascibiolsci.v34i4.8959

<p class="aTitulodoArtigo"><em>In vitro</em> tests could be a valuable tool for the evaluation of medicinal plants’ antimicrobial activity. <em>Mentha arvensis</em> of the Lamiaceae family is one of the most frequently traditional plants used in Brazil. Hydroalcoholic extracts of<em> M. arvensis</em> were analyzed for antimicrobial activity on <em>Streptococcus</em> <em>mutans</em>,<em> Streptococcus sobrinus </em>and <em>Candida albicans</em>. Three different assays (agar diffusion, broth macro- and micro-dilution methods) were used to evaluate antimicrobial activity. Although hydroalcoholic extracts of <em>M. arvensis</em> did not show any antibacterial effect, its antifungal activity against<em> C. albicans</em> was revealed. According to the micro-dilution broth assay, MIC of the hydroalcoholic extract from leaves of <em>M. arvensis</em> on <em>Candida albicans</em> strains ranged between 625 and 2500 mg mL^-1. Results suggest that <em>M. arvensis</em> hydroalcoholic extract may be considered a potentially antifungal agent against <em>C. albicans</em>, and a possible item for human antibiotic therapy.  However, further biological tests on the plant’s efficacy and side-effects are necessary before its use on humans.</p><p class="aresumo"><strong> </strong></p> <p class="apalavrachave"> </p><br /

In vitro study on the antimicrobial effect of hydroalcoholic extracts from Mentha arvensis L. (Lamiaceae) against oral pathogens=Estudo in vitro do efeito antimicrobiano dos extratos hidroalcólicos de Mentha arvensis L. (Lamiaceae) contra patógenos orais

In vitro tests could be a valuable tool for the evaluation of medicinal plants’ antimicrobial activity. Mentha arvensis of the Lamiaceae family is one of the most frequently traditional plants used in Brazil. Hydroalcoholic extracts of M. arvensis were analyzed for antimicrobial activity on Streptococcus mutans, Streptococcus sobrinus and Candida albicans. Three different assays (agar diffusion, broth macro- and micro-dilution methods) were used to evaluate antimicrobial activity. Although hydroalcoholic extracts of M. arvensis did not show any antibacterial effect, its antifungal activity against C. albicans was revealed. According to the micro-dilution broth assay, MIC of the hydroalcoholic extract from leaves of M. arvensis on Candida albicans strains ranged between 625 and 2500 g mL-1. Results suggest that M. arvensis hydroalcoholic extract may be considered a potentially antifungal agent against C. albicans, and a possible item for human antibiotic therapy. However, further biological tests on the plant’s efficacy and side-effects are necessary before its use on humans. <br><br>Testes in vitro podem ser uma ferramenta valiosa para a avaliação da atividade antimicrobiana de plantas medicinais. Mentha arvensis é uma das plantas medicinais brasileiras mais frequentemente utilizadas e pertence à família Lamiaceae. No presente estudo, extratos hidroalcólicos de M. arvensis foram analisados quanto à sua atividade antimicrobiana sobre Streptococcus mutans, Streptococcus sobrinus e Candida albicans. Três diferentes ensaios (métodos de difusão em ágar, macro e microdiluição em caldo) foram utilizados para avaliação da atividade antimicrobiana. Embora os extratos hidroalcólicos de M. arvensis não demonstraram qualquer efeito antibacteriano, eles apresentaram atividade antifúngica contra C. albicans. Baseado no ensaio de microdiluição em caldo, a CIM do extrato hidroalcólico das folhas de M. arvensis sobre cepas de C. albicans variaram de 625 a 2500 g mL-1. Estes achados sugerem que o extrato hidroalcólico de M. arvensis pode ser considerado um agente antifúngico em potencial contra C. albicans, e um possível candidato para antibioticoterapia humana. Contudo, mais testes biológicos sobre a eficácia e efeitos adversos desta planta são necessários antes do seu uso em humanos

Antibacterial Potential of Essential Oils Against Ground Beef Isolates

The objective of this study was to evaluate the antibacterial activity of different EOs against Escherichia coli, Salmonella spp., and coagulase-positive staphylococcus isolated from ground beef. The EOs had values varying from 0.78μl/mL to 100μl/mL, and the essential oil of Citrus lemon did not present any bacterial activity against the studied strains. For E. coli, the essential oil of Cinnamomum zeylanicum presented the best inhibitory activity (MIC = 0.78μl/mL to 1.56μl/mL). In Salmonella spp., the EOs of Cymbopogon citratus (MIC = 12.5μl/mL and 25.0μl/mL), C. zeylanicum (MIC = 25.0 µL/mL) and Ocimum basilicum (MIC = 6.25μl/mL, 12.5μl/mL and 50.0μl/mL) exhibited similar results. The EOs of C. zeylanicum and Eugenia caryophyllata demonstrated the lowest average values of study against coagulase-positive Staphylococcus (MIC = 3.12μl/mL, 6.25μl/mL and 12.5μl/mL). With the data obtained in the study, it can be observed the potential of EOs in the control of pathogenic food microorganisms, as well as validate future researches on the proprieties and active compounds of these products, besides the toxicity of these compounds and the possible alterations that can be caused on the food