Evaluation of the antibacterial activity of trans-anethole against Enterococcus cloacae and Enterococcus faecalis strains of food origin / Avaliação da atividade antibacteriana do trans-anetol contra cepas de Enterobacter cloacae e Enterococcus faecalis de origem alimentar

The present study sought to evaluate the antibacterial activity of trans-anethole against food-borne strains of Enterobacter cloacae and Enterococcus faecalis. The study was performed using Minimum Inhibitory Concentration (MIC), and Minimum Bactericidal Concentration (MBC) methods, in addition, disc diffusion technique was used to evaluate the association of trans-anethole with synthetic antimicrobials. Minimum Inhibitory Concentration for Adherence (MICA) testing was also performed. The results revealed that trans-anethole presents no antibacterial activity at any of the concentrations used against the E. cloacae strains tested. However, trans-anethole presented antibacterial effect against five of the six E. faecalis bacterial strains tested, with MIC values ranging from 500 µg/mL to 1000 µg/mL. Further, when analyzing the MBC results against E. faecalis, it was observed that the compound presented values ranging from 500 µg/mL to 1000 µg/mL. As for the associations, it was observed that transanethole when combined with the antimicrobials ampicillin, gentamicin, ciprofloxacin, and ceftriaxone presented synergistic effect against most strains of E. faecalis. However, both trans-anethole and the control chlorhexidine (0.12%) presented no antibiofilm effects against strains of E. faecalis. In short, trans-anethole presented potential antibacterial against E. faecalis strains of food origin, and may upon further study, it may be used alone or in association with synthetic antimicrobials to combat infections caused by this bacterium.

O presente estudo procurou avaliar a atividade antibacteriana do trans-anetol contra cepas de Enterobacter cloacae e Enterococcus faecalis de origem alimentar. O estudo foi realizado utilizando métodos de Concentração Inibitória Mínima (CIM), e Concentração Bactericida Mínima (CBM), além disso, foi utilizada a técnica de difusão de disco para avaliar a associação do trans-anetol com antimicrobianos. O teste de Concentração Inibitória Mínima de Aderência (CIMA) também foi realizado. Os resultados revelaram que o trans-anetol não apresentou atividade antibacteriana em nenhuma das concentrações utilizadas contra as cepas de E. cloacae testadas. No entanto, o trans-anetol apresentou efeito antibacteriano contra cinco das seis cepas bacterianas de E. faecalis testadas, com valores de CIM variando de 500 µg/mL a 1000 µg/mL. Além disso, ao analisar os resultados da CBM contra E. faecalis, observa-se que o composto apresentou valores variando de 500 µg/mL a 1000 µg/mL. Quanto às associações, observou-se que o trans-anetol quando combinado com os antimicrobianos ampicilina, gentamicina, ciprofloxacino, e ceftriaxona apresentou efeito sinérgico contra a maioria das cepas de E. faecalis. No entanto, tanto o trans-anetol quanto o controle clorexidina (0,12%) não apresentaram efeito antibiofilme contra a cepa de E. faecalis. Em suma, o transanetol apresentou potencial antibacteriano contra cepas de E. faecalis de origem alimentar, podendo, mediante estudos mais aprofundados, ser utilizado isoladamente ou em associação com antimicrobianos sintéticos para combater infecções causadas por esta bactéria.

Endophytic Enterobacter cloacae exhibits antagonistic activity against Pythium damping-off of cucumber / Enterobacter cloacae endofítica exibe atividade antagonista contra a podridão de pepino causada por Pythium

The study was performed to examine the potential presence of biological control agents against Pythium damping-off disease of cucumber.Examining eleven bacterial strains isolated from acid lime roots and rhizosphere soil showed that the bacterial strain RB1 was the most efficient in suppressing mycelial growth of P. aphanidermatum, producing an inhibition zone of 5mm. Scanning electron microscopy study of the mycelia at the interaction zone showed that the pathogen hyphae were deformed and shriveled by the bacterial strain.In pot experiments, pretreatment with the RB1 bacterial strain reduced disease incidence significantly by 63%.The bacterial strain did not exhibit any negative significant effects on cucumber growth (plant height and root dry weight) in comparison with untreated control under growth chamber conditions. Molecular identification of strain RB1 based on the 16S rRNA gene revealed that it is Enterobacter cloacae. Findings from this study suggested that E. cloacae has a potential to be used as a biocontrol agent for suppressingcucumber damping-off disease caused by P. aphanidermatum. This is the first report of the antagonistic activity of E. cloacae against P. aphanidermatum-induced damping-off of cucumber.(AU)

O estudo foi realizado para examinar a presença potencial de agentes no controle biológico da doença do apodrecimento do pepino causado por Pythium. Examinando onze cepas bacterianas isoladas de raízes de cal ácida e solo da rizosfera mostraram que a cepa bacteriana RB1 foi a mais eficiente na supressão do crescimento micelial de P. aphanidermatum, produzindo uma zona de inibição de 5 mm. O estudo de microscopia eletrônica de varredura dos micélios na zona de interação mostrou que as hifas do patógeno foram deformadas e enrugadas pela cepa bacteriana. Em experimentos com vasos, o pré-tratamento com a cepa bacteriana RB1 reduziu significativamente a incidência da doença em 63%. A cepa bacteriana não exibiu nenhum efeito negativo. Efeitos significativos no crescimento do pepino (altura da planta e peso seco da raiz), em comparação com o controle não tratado sob condições da câmara de crescimento. A identificação molecular da cepa RB1 com base no gene 16S rRNA revelou que é a Enterobacter cloacae. Os resultados deste estudo sugerem que E. cloacae tem potencial para ser usado como agente de biocontrole para suprimir a doença da podridão de pepino causada por P. aphanidermatum. Este é o primeiro relato da atividade antagônica de E. cloacae contra o amortecimento induzido por P. aphanidermatum de pepino.(AU)

Raoultella ornithinolytica isolation in cloacal microbiota of Tinamus solitarius: preliminary data

Raoultella ornithinolytica is a gram-negative aerobic bacterium belonging to Enterobacteriaceae family, an emerging pathogen that causes several pathogenic conditions in man, with little veterinary importance; however, its identification is underestimated by conventional laboratory techniques. The present study reports the identification of R. ornithinolytica in Tinamus solitaries, during a routine sanitary evaluation of aerobic enterobacteria in cloacal microbiota of birds belonging to the Güira Oga Center, Puerto Iguazu, Argentina. The sample was preliminary classified as Klebsiella spp.; however, after the use of the MALDI-TOF MS technique it was identified as R. ornithinolytica. The sample was submitted to an antimicrobial susceptibility test, where it showed a similar pattern profile as reported in the literature, with resistance to ampicillin and other -lactam antibiotics. It is possible that Raoultella spp are more common in birds as it is reported. Therefore, review studies on bacteria collections of avian origin, as well as cases with confirmation of Klebsiella, should be deeply evaluated in laboratorial routine, mainly due to the pathogenic potential of R. ornithinolytica for Poultry, as well as for public health.(AU)

Raoultella ornithinolytica isolation in cloacal microbiota of Tinamus solitarius: preliminary data

Raoultella ornithinolytica is a gram-negative aerobic bacterium belonging to Enterobacteriaceae family, an emerging pathogen that causes several pathogenic conditions in man, with little veterinary importance; however, its identification is underestimated by conventional laboratory techniques. The present study reports the identification of R. ornithinolytica in Tinamus solitaries, during a routine sanitary evaluation of aerobic enterobacteria in cloacal microbiota of birds belonging to the Güira Oga Center, Puerto Iguazu, Argentina. The sample was preliminary classified as Klebsiella spp.; however, after the use of the MALDI-TOF MS technique it was identified as R. ornithinolytica. The sample was submitted to an antimicrobial susceptibility test, where it showed a similar pattern profile as reported in the literature, with resistance to ampicillin and other -lactam antibiotics. It is possible that Raoultella spp are more common in birds as it is reported. Therefore, review studies on bacteria collections of avian origin, as well as cases with confirmation of Klebsiella, should be deeply evaluated in laboratorial routine, mainly due to the pathogenic potential of R. ornithinolytica for Poultry, as well as for public health.

Verificação da contaminação em ovos provenientes dos sistemas de produção caipira e granja, comercializados no município de Ipiaú-BA / Verification of eggs contamination the production farm, marketed in the city of Ipiau-BA

o consumo de ovos in natura ou de alimentos que não sofrem cozimento constitui-se em um grande risco à saúde, pois este tipo de alimento serve como veículo a diversos patógenos, em especial coliformes termotolerantes, os principais envolvidos em casos de toxinfecção alimentar. A identificação dos micro-organismos causadores de enfermidades permite avaliar a qualidade higiênica dos ovos comercializados. A realização desta pesquisa permitiu a identificação de alguns desses patógenos no município objeto do estudo. Foi verificado que as amostras advindas do sistema caipira de produção apresentaram resultados de contaminação em 13 (54,16%), enquanto que nas amostras de granja 7 (29,16%) foram positivas. As amostras de cascas dos ovos caipiras estavam predominantemente contaminadas por Enterobacter cloacae (29,16%) e Klesiella oxytoca (12,5%). Enquanto que nas amostras de cascas dos ovos de granja os micro-organismos predominantes foram Enterobacter cloacae ( 16,66%) e Klebsiella pneumoniae (4,16%). (AU)

The consumption of eggs in natura or raw foods constitutes in a big risk to health, because this type of food serves as a vehicle to various pathogens, especially fecal coliform, the main involved in cases of food poisoning. The identification of microorganisms that causes deseases, alow assess the hygienic quality of marketed eggs. This research allowed the identification of some of these pathogens in the municipality studied. It was noted that the samples coming from the rustic production system showed contamination results in 13 (54.16%), while in the factory-farmed samples 7 (29.16%) was positives. The Samples of shells of free-range eggs were predominantly contaminated by Enterobacter cloacae (29./6%) and Klesiella oxytoca (12.5%). While in samples of shells of factory-farmed egg the microorganisms predominant were Enterobacter cloacae (J6.66%) and Klebsiella pneumoniae (4.16%). (AU)