Efeito do “Kéfigel®“ em bactérias isoladas de infeções do pé diabético

Um dos maiores problemas da atualidade na saúde humana é o aparecimento de resistência aos antibióticos, particularmente em meio hospitalar e em doenças recorrentes como é o caso de infeções de úlceras do pé diabético. A diabetes tem vindo a aumentar na população mundial e destes doentes, cerca de 5 a 25% apresentam ulceração do pé. Associadas às infeções do pé diabético encontram-se primordialmente Staphylococcus aureus, quer estirpes sensíveis à meticilina (MSSA) quer estirpes resistentes (MRSA), estas últimas apresentando resistência ao tratamento com os antibióticos comerciais. Este fenómeno tem levado à procura de alternativas, quer seja pela síntese de novos compostos antibacterianos, quer seja pela procura de produtos naturais com propriedades antibacterianas. Neste contexto, surgiu este trabalho no qual se avaliou o efeito antibacteriano de um produto comercial, Kéfigel®, formulado à base de compostos naturais (urtiga, lavanda e grãos de kefir) que tem sido indicado, ainda que empiricamente, como tendo propriedades antibacterianas. Assim, o potencial biológico quer do produto comercial, o Kéfigel®, quer dos seus principais componentes, foi avaliado em isolados de Gram positivo de úlceras do pé diabético, nomeadamente Staphylococcus aureus (MSSA e MRSA). Para tal, utilizaram-se os métodos de difusão em disco em meio sólido, da concentração mínima inibitória (CIMs), concentração mínima bactericida (CMB) e efeito na taxa específica de crescimento. Os resultados mostraram que pelo método de difusão em disco, apenas os extratos etanólicos de urtiga e lavanda apresentaram atividade antibacteriana, e esta maioritariamente bacteriostática. Estes extratos apresentaram uma eficácia entre 50 a 100%, relativamente ao antibiótico gentamicina. Por outro lado, o Kéfigel®, na concentração testada, afetou a taxa específica de crescimento dos isolados S. aureus, já que após poucas horas de incubação o crescimento da maioria dos isolados era inibido, revelando por isso um efeito bacteriostático. Assim, o Kéfigel® parece ser um produto natural com um potencial de ação efetiva contra S. aureus. O uso deste produto na prevenção das infeções das úlceras do pé diabético pode ser de grande utilidade, no entanto mais estudos terão que ser feitos, nomeadamente testes com concentrações mais elevadas de Kéfigel® e avaliação de efeito sinérgico com antibióticos.Nowadays, concerning human health, one of the main problems is the emergence of antibiotic resistance, particularly in hospital environment and in recurrent diseases such as diabetic foot ulcers. Diabetes is increasing in the world's population and about 5 to 25% of patients have ulceration of the foot. Associated with the diabetic foot infections are primarily Staphylococcus aureus, methicillin-sensitive strains (MSSA) and methicillin-resistant strains (MRSA), these last showing several resistances to treatment with traditional antibiotics. As consequence, there is an increasing for search alternatives, either by synthesis of new compounds or by the research for natural products with antibacterial properties. In this context, this work investigated the antibacterial effect of a commercial product, Kéfigel ®, composed by natural compounds (nettle, lavender and kefir grains) which has been indicated, although empirically, as having antibacterial properties. Thus, biological potential of this commercial product, the Kéfigel ®, and its main components, were evaluated against Gram-positive isolates collected from diabetic foot ulcers, namely Staphylococcus aureus (MSSA and MRSA). The disk diffusion in solid medium, minimum inhibitory concentration (MICs), minimum bactericide concentration (MBC) and effects on specific growth rate were the methods used in this study. The results of disk diffusion method showed that only ethanolic extracts of nettle and lavender has antibacterial activity, which was mainly bacteriostatic. These extracts presented effectiveness between 50 to 100%, in relation to the antibiotic gentamicin. On the other hand, the Kéfigel ® affects the specific growth rate of S. aureus isolates, at the concentration tested, since after a few hours of incubation growth of the majority of isolates was inhibited, revealing a bacteriostatic effect. Based on these results, the Kéfigel® seems to be a natural product with a potential antibacterial activity against S. aureus. The use of this product in the prevention of infections of diabetic foot ulcers can be very useful. Nevertheless, further studies are necessary, in particular tests with higher concentrations of Kéfigel ® and synergism studies with antibiotics.En la actualidad, uno de los problemas principales de la salud humana es el aparecimiento de la resistencia antibiótica, sobretodo en medio hospitalario y en enfermedades recurrentes como es el caso de las infecciones de ulceras del pie diabético. La frecuencia de diabetes está aumentando en todo el mundo y entre el 5 y el 25% de los pacientes presentan ulceración del pie. Asociadas a las infecciones del pie diabético se encuentran principalmente Staphylococcus aureus, tanto estirpes sensibles a la meticilina (MSSA), como estirpes resistentes (MRSA), estas presentando resistencia al tratamiento con antibióticos comerciales. Este fenómeno lleva a la demanda de alternativas, ya sea por síntesis de nuevos compuestos antibacterianos, o bien por la investigación de productos naturales con propiedades antibacterianas. En este contexto surge este trabajo que pesquisó el efecto antibacteriano de un producto comercial, Kéfigel®, elaborado con base en compuestos naturales (ortiga, lavándula y granos de kefir), indicado, aunque de forma empírica, como producto con propiedades antibacterianas. Así, el potencial, ya sea del producto comercial Kéfigel®, o bien de sus principales compuestos, han sido evaluado en aislados Gram positivo de ulceras del pie diabético, destacadamente Staphylococcus aureus (MSSA e MRSA). Para el efecto, se usaran métodos de difusión en disco en medio solido, de concentración mínima inhibitoria (CIMs), de concentración mínima bactericida (CMB) y efecto en la tasa específica de crecimiento. Los resultados muestran que por el método de difusión en disco, los extractos etanolicos de ortiga y lavándula, fueron los que presentaron actividad antibacteriana, esta mayormente bacteriostática. Estos extractos presentaron una eficacia entre el 50 y el 100% en relación al antibiótico gentamicina. Al mismo tiempo, el Kéfigel®, en la concentración testada, afectó la tasa especifica de crecimiento de los aislados S. aureus ya que, pocas horas pasadas de incubación, el crecimiento de gran parte de los aislados fue inhibido, exponiendo así un efecto bacteriostático. En conclusión, Kéfigel® se presenta como un producto natural con potencial de acción efectiva contra el S. aureus. El uso de este producto en la prevención de las infecciones de ulceras del pie diabético puede que sea de gran utilidad, sin embargo se presentan como necesarios más estudios, esencialmente estudios con concentraciones más elevadas de Kéfigel® y una evaluación del efecto sinérgico con antibióticos

Antagonistic activities of Kefirgel and Kefirgel products against Staphylococcus aureus isolated from diabetic ulcers

Diabetic foot ulcers are often complicated by infection and among pathogens the Gram-positive Staphylococcus aureus is the most common isolated. Also concomitantly, the high prevalence of methicillin-resistant S. aureus (MRSA) was significant impact on successful treatment of infected foot ulcers. In this context, the purpose of the present study was to evaluate the antibacterial properties of Kefigel®, a natural product composed by nettle (Urtica dioica L), lavender (Lavandula angustifolia Mill) and kefir grains, which have been reported as to having antibacterial activity against several diseases. Here, antibacterial effect of Kefigel® and its components were investigated against 20 S. aureus isolates (10 MSSA and 10 MRSA) collected from several diabetic foot ulcers. To assess antibacterial activity, the disk diffusion assay method, minimum inhibitory concentration (MIC), minimal bacterial activity and effects on specific growth rate, were applied. Results showed that by diffusion method, only etanolic extracts of nettle and lavender showed antibacterial activity and their effects were mainly bacteriostatic. Compared to the antibiotic gentamicin, the nettle and lavender extracts showed an efficacy between 50 and 100% relative to the antibiotic. Generally, the MRSA isolates sowed higher inhibition halos comparing MSSA isolates. In turns, Kefigel® (40mg.mL-1) affects the specific growth rate of S. aureus isolates, since after incubation for 9h almost MSSA isolates growth were inhibited. A bactericide effect was observed only against one isolates MRSA. These findings indicate a potential use of Kefigel® as a natural product having an effective effect against Staphylococus aureus. The topical use of this product for prevention of diabetic foot ulcers infections can be useful, however further investigation will be made, namely tests with high Kefigel® concentrations and synergetic effects with antibiotics

Antibacterial potential of Urtica dioica and Lavandula angustifolia extracts against methicillin resistant Staphylococcus aureus isolated from diabetic foot ulcers

Despite the antibacterial potential of plant extracts against several bacterial infections, until now, no major studies have been published about the effect of lavender and nettle leaves against methicillin-sensitive and methicillin-resistant strains of Staphylococcus aureus (MSSA and MRSA, respectively). Thus, the authors studied their antibacterial potential against MSSA and MRSA from diabetic foot ulcers in order to find alternatives to the systematic use of antibiotics. Phenolic acids, flavonoids, flavones and flavonols were extracted from lavender and nettle leaves and characterized by HPLC-DAD/Vis. Disc diffusion assay and minimum inhibitory concentration (MIC) were used to assess their antibacterial activity. A direct association between the high content of hydroxycinnamic acids (chlorogenic acid, caffeic acid, rosmarinic acid) and flavonoids (quercetin) and decreasing bacterial growth activity was noted. The fact that lavender and nettle are rich in hydroxycinnamic acids and quercetin seems to explain the high antibacterial potential of these plant and the differences between them.The authors acknowledge the financial support provided by the FCT-Portuguese Foundation for Science and Technology (Carla Dias- SFRH/BD/90120/2012 and Alfredo Aires-SFRH/BPD/65029/2009), under the Project PEst-OE/AGR/UI4033/2014.info:eu-repo/semantics/publishedVersio

Antibacterial screening of active ethanolic fractions of Urtia dioica L. against pathogenic bacteria from gastrointestinal and respiratory tract

Medicinal plants are largely explored source of drug repository. Although a huge number of antibiotics are available for treatment of microbial infections, development of resistance mechanism against antibiotics is nowadays a major health concern. Therefore the needs of discover new antimicrobial compounds with high safety index is always recurrent and medicinal plants have great potential for providing novel drug leads with novel mechanism of action. Historically, this plants have always been a source of inspiration for new drug compounds. In this context we evaluate the antimicrobial potential of various extracts (produced by a partial purification in a silica gel column) of Urtica dioica L (stinging nettle) (Urticaceae) collected from Vila Real region (Portugal), against 10 different bacteria isolates collected from clinical patients (gastrointestinal segments and respiratory tract), namely 4 Gram positive [2 Staphylococcus aureus (MRSA), Staphylococus aureus (MSSA), Staphylococcus saprophyticus, and Enterococcus faecalis]and 5 Gram negative[Salmonella thyphi, Echerichia coli, Klebsiela pneumoniae, Pseudomonas aeruginosa and Proteus mirabilis]. The current study represents the investigation of antimicrobial activity of U. dioica from four fractions (Hexane, Ethyl-acetate, ethanol and water) that were prepared using sequential fractionating method by column chromatography. The antibacterial activity was assessed by disk diffusion and minimum inhibitory concentration methods. The phytochemical composition of U. dioica fractions were assessed by HPLC-UV-DAD. Our results showed that only ethanolic fractions had antibacterial activity but only in S. aureus (MRSA and MSSA), S. saprophyticus and E. faecallis isolates. Thus, only the Gram positives were affected by U.doica extracts. The inhibition zone diameter halos ranges from 0 to 23 mm and the minimum inhibitory concentration (MIC) were6.25 mg.mL-1 for MRSA isolates and 0.78 mg.mL-1 for S. saprophyticus and E. faecalis. Our results show a direct association between the antibacterial activities and high content of phytochemicals detected in the ethanolic fractions particularly with phenolic acids (chlorogenic and ferulic acids) and flavonols (rutin, isoquercetin and quercetin isomers). Our observations suggest the importance of ethnomedicinal use of U. dioica, which could be used by the pharmaceutical industry as source of a natural antimicrobial agents and antioxidant compounds

Antimicrobial activity against Staphylococcus aureus (MRSA and MSSA): bioactive compounds potencial

Hospital infections in diabetic patients are associated with Staphylococcus aureus, including S. aureus resistant to methicillin (MRSA). Besides their increase incidence, MRSA is considered one of the main pathogens causing nosocomial infections and, furthermore, many of these MRSA isolates are becoming multidrug resistant, constituting a public health problem. As a consequence, there is an increase for the search of alternatives to antibiotics, either by synthesis of new compounds or by the research for natural products with antibacterial properties. In this context, this work investigated the antibacterial effect of natural compounds present in plants (Urtica dioica L. and Lavandula angustifolia Mill) in several Gram-positive isolates, collected from diabetic foot ulcers, namely Staphylococcus aureus (MRSA and MSSA). Different plant extracts (extraction in ethanol, acetone and water) were tested and the antibacterial activity was evaluated by disk diffusion assay method, minimum inhibitory concentration (MICs), minimum bactericide concentration (MBC) and growth rate (µ). Spectrophotometry methods were used to assess the total phenolic content and HPLC-DAD/VIS method was used to identify and quantify the phytochemicals present in the plant extracts. Best antibacterial activity against both MRSA and MSSA was observed with the ethanolic extracts, reaching an effectiveness of 100%, in relation to the antibiotic gentamicin. For both plant extracts, the effect on bacterial growth rate was predominantly bacteriostatic. These findings indicate a potential of these plant extracts as a natural product with antimicrobial activity. Their use in formulations, alone or with synergistic effect with conventional antibiotics could be an alternative to limit the infections of these bacteria.info:eu-repo/semantics/publishedVersio