RESUMO
Sulfonamide derivatives have numerous pharmaceutical applications having antiviral, antibacterial, antifungal, antimalarial, anticancer, and antidepressant activities. The structural flexibility of sulfonamide derivatives makes them an excellent candidate for the development of new multi-target agents, although long-time exposure to sulfonamide drugs results in many toxic impacts on human health. However, sulfonamides may be functionalized for developing less toxic and more competent drugs. In this work, sulfonamides including Sulfapyridine (a), Sulfathiazole (b), Sulfamethoxazole (c), and Sulfamerazine (d) are used to synthesize Schiff bases of 7-hydroxy-4-methyl-2-oxo-2H-chromene-8-carbalde-hyde (1a-1d). The synthesized compounds were spectroscopically characterized and tested against hospital isolates of three Gram-positive (Methicillin-resistant Staphylococcus aureus PH217, Ampicillin-resistant Coagulase-negative Staphylococcus aureus, multidrug-resistant (MDR) Enterococcus faecalis PH007R) and two Gram-negative bacteria (multidrug-resistant Escherichia coli, and Salmonella enterica serovar Typhi), compared to the quality control strains from ATCC (S. aureus 29213, E. faecalis 25922, E. coli 29212) and MTCC (S. Typhi 734). Two of the four Schiff bases 1a and 1b are found to be more active than their counterpart 1c and 1d; while 1a have showed significant activity by inhibiting MRSA PH217 and MDR isolates of E. coli at the minimum inhibitory concentration (MIC) of 150 µg/mL and 128 µg/mL with MBC of 1024 µg/mL, respectively. On the other hand, the MIC of 1b was 150 µg/mL against both S. aureus ATCC 29213 and Salmonella Typhi MTCC 734, compared to the control antibiotics Ampicillin and Gentamycin. Scanning electron microscopy demonstrated the altered surface structure of bacterial cells as a possible mechanism of action, supported by the in-silico molecular docking analysis.
Assuntos
Staphylococcus aureus Resistente à Meticilina , Staphylococcus aureus , Humanos , Simulação de Acoplamento Molecular , Cromonas/farmacologia , Escherichia coli , Bases de Schiff/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Sulfanilamida , Ampicilina/farmacologia , Sulfonamidas/farmacologia , Testes de Sensibilidade MicrobianaRESUMO
Asphodelus fistulosus (A. fistulosus) is a wild plant grows in Jordan. Traditionally, it is used to treat different medical conditions and diseases such as respiratory ailments, against burns and dermatomucosal infections.This study aims to find out the effects of A. fistulosus aqueous and ethanolic crude extracts on Staphylococcus aureus(S. aureus) as gram positive bacteria and Escherichia coli (E. coli) as gram negative bacteria and to investigate which one will be affected either by aqueous and/or ethanolic crude extracts of A. fistulosus shooting parts that were collected from Jerash in the north of Jordan. Agar well diffusion method was used to evaluate the antibacterial activity of the crude extracts. In addition, MIC (minimum inhibitory concentration) as well as MBC (minimum bactericidal concentration) were determined against both types of bacteria. The results showed that flower aqueous extract of A. fistulosus was very effective against E. coli (20.0 ± 0.50) mm and caused a (14.0 ± 0.50) mm inhibition to S. aureus. The ethanolic extract of stem was very effective cauesed a (19.0 ± 0.50) mm inhibition in both bacterial species. Respectively, both S. aureus and E. coli were inhibited by ethanolic and aqueous extracts (mixture1 and mixture2) (15.0 ± 0.00 mm and 10.5 ± 0.50 mm). The highest antimbacterial activity was observed for the leaves aqueous extract against E.coli (0.06120 mg/mL). The obtained MIC values from A. fistulosus parts extracts demonstrated antibacterial activity ranged between 7.606 and 0.06120 mg/mL. The highest antimicrobial activity was recorded in the leaves aqueous extract against E. coli.The MBC value of stem aqueous extract was 5.00 mg/mL against both S. aureus and E. coli. On the other hand, ethanolic and aqueous extracts of the leaves gave MBC values 5.00 mg/mL, and 0.156 mg/mL, respectively, against E. coli.Based on the results of this study, it can be concluded that there is good inhibitory effect of aqueous and ethanolic of A. fistulosus shooting parts extracts on growth of E. coli and S. aureus. Adding to that, stem ethanolic extract has the most effective against S. aureus while aqueous extract of flower has the most effective against E. coli.So, it is recommended to have further future studies on the A. fistulosus shooting parts crude extract bioactive components and the mechanism of how these constituents affect these types of bacteria.
Asphodelus fistulosus (A. fistulosus) é uma planta selvagem que cresce na Jordânia. Tradicionalmente, é usada para tratar diferentes condições médicas e doenças, como doenças respiratórias, contra queimaduras e infecções dermatomucosas. Bactérias positivas e Escherichia coli (E. coli) como bactérias gram-negativas e investigar qual delas será afetada por extratos brutos aquosos e/ou etanólicos de partes de tiro de A. fistulosus que foram coletadas em Jerash no norte da Jordânia. O método de difusão em poço de ágar foi utilizado para avaliar a atividade antibacteriana dos extratos brutos. Além disso, MIC (concentração inibitória mínima) e MBC (concentração bactericida mínima) foram determinados contra ambos os tipos de bactérias. Os resultados mostraram que o extrato aquoso de flores de A. fistulosus foi muito eficaz contra E. coli (20,0 + 0,50 mm) e causou uma inibição (14,0 + 0,50 mm) para S. aureus. O extrato etanólico do caule foi muito eficaz, causando inibição (19,0 + 0,50 mm) em ambas as espécies bacterianas. Respectivamente, tanto S. aureus quanto E. coli foram inibidos pelos extratos etanólico e aquoso (mistura 1 e mistura 2) (15,0 + 0,00 mm e 10,5 + 0,50 mm). A maior atividade antibacteriana foi observada para o extrato aquoso das folhas contra E. coli (0,06120 mg/mL). Os valores de CIM obtidos dos extratos de partes de A. fistulosus demonstraram atividade antibacteriana variando entre 7,606 e 0,06120 mg/mL. A maior atividade antimicrobiana foi registrada no extrato aquoso das folhas contra E. coli. O valor de CBM do extrato aquoso do caule foi de 5,00 mg/mL contra S. aureus e E. coli. Por outro lado, os extratos etanólico e aquoso das folhas apresentaram valores de CBM de 5,00 mg/mL e 0,156 mg/mL, respectivamente, contra E. coli, efeito de extratos aquosos e etanólicos de partes de tiro de A. fistulosus no crescimento de E. coli e S. aureus. Somando-se a isso, o extrato etanólico do caule é o mais eficaz contra S. aureus enquanto o extrato aquoso da flor é o mais eficaz contra E. coli. Assim, recomenda-se a realização de estudos futuros sobre os componentes bioativos do extrato bruto de partes fotografais de A. fistulosus e o mecanismo de como esses constituintes afetam esses tipos de bactérias.
Assuntos
Animais , Doenças Respiratórias , Staphylococcus aureus , Escherichia coli , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Antibacterianos/uso terapêuticoRESUMO
Abstract The present study was aimed to manifest the antibacterial and antifungal activity of methanolic extracts of Salix alba L. against seven Gram-positive and Gram-negative bacterial pathogens e.g. Streptococcus pyogenes, Staphylococcus aureus (1), S. aureus (2), Shigella sonnei, Escherichia coli (1), E. coli (2) and Neisseria gonorrhoeae and three fungal isolates from the air such as Aspergillus terreus, A. ornatus, and Rhizopus stolonifer. Two different serotypes of S. aureus and E. coli were used. The agar well-diffusion method results showed the dose-dependent response of plant extracts against bacterial and fungal strains while some organisms were found resistant e.g. E. coli (1), S. sonnei, A. terreus and R. stolonifer. The highest antibacterial activity was recorded at 17.000±1.732 mm from 100 mg/mL of leaves methanolic extracts against S. pyogenes while the activity of most of the pathogens decreased after 24 h of incubation. The highest antifungal activity was reported at 11.833±1.0 mm against A. ornatus at 50 mg/mL after 48 h of the incubation period. These experimental findings endorse the use of S. alba in ethnopharmacological formulations and suggest the use of methanolic extracts of the said plant to develop drugs to control the proliferation of resistant disease causing pathogenic microbes.
Resumo O presente estudo teve como objetivo manifestar a atividade antibacteriana e antifúngica de extratos metanólicos de Salix alba L. contra sete patógenos bacterianos Gram-positivos e Gram-negativos. Streptococcus pyogenes, Staphylococcus aureus (1), S. aureus (2), Shigella sonnei, Escherichia coli (1), E. coli (2) e Neisseria gonorrhoeae e três isolados de fungos do ar, como Aspergillus terreus, A. ornatus, e Rhizopus stolonifer. Dois sorotipos diferentes de S. aureus e E. coli foram usados. Os resultados do método de difusão em ágar mostraram a resposta dependente da dose de extratos de plantas contra cepas de bactérias e fungos, enquanto alguns organismos foram considerados resistentes, e.g. E. coli (1), S. sonnei, A. terreus e R. stolonifer. A maior atividade antibacteriana foi registrada em 17.000 ± 1.732 de 100 mg/mL de extratos metanólicos de folhas contra S. pyogenes, enquanto a atividade da maioria dos patógenos diminuiu após 24 h de incubação. A maior atividade antifúngica foi relatada em 11,833 ± 1,0 contra A. ornatus a 50 mg/mL após 48 h do período de incubação. Esses achados experimentais endossam o uso de S. alba em formulações etnofarmacológicas e sugerem o uso de extratos metanólicos da referida planta para o desenvolvimento de fármacos que controlem a proliferação de doenças resistentes que causam micróbios patogênicos.
RESUMO
Abstract The present study was aimed to manifest the antibacterial and antifungal activity of methanolic extracts of Salix alba L. against seven Gram-positive and Gram-negative bacterial pathogens e.g. Streptococcus pyogenes, Staphylococcus aureus (1), S. aureus (2), Shigella sonnei, Escherichia coli (1), E. coli (2) and Neisseria gonorrhoeae and three fungal isolates from the air such as Aspergillus terreus, A. ornatus, and Rhizopus stolonifer. Two different serotypes of S. aureus and E. coli were used. The agar well-diffusion method results showed the dose-dependent response of plant extracts against bacterial and fungal strains while some organisms were found resistant e.g. E. coli (1), S. sonnei, A. terreus and R. stolonifer. The highest antibacterial activity was recorded at 17.000±1.732 mm from 100 mg/mL of leaves methanolic extracts against S. pyogenes while the activity of most of the pathogens decreased after 24 h of incubation. The highest antifungal activity was reported at 11.833±1.0 mm against A. ornatus at 50 mg/mL after 48 h of the incubation period. These experimental findings endorse the use of S. alba in ethnopharmacological formulations and suggest the use of methanolic extracts of the said plant to develop drugs to control the proliferation of resistant disease causing pathogenic microbes.
Resumo O presente estudo teve como objetivo manifestar a atividade antibacteriana e antifúngica de extratos metanólicos de Salix alba L. contra sete patógenos bacterianos Gram-positivos e Gram-negativos. Streptococcus pyogenes, Staphylococcus aureus (1), S. aureus (2), Shigella sonnei, Escherichia coli (1), E. coli (2) e Neisseria gonorrhoeae e três isolados de fungos do ar, como Aspergillus terreus, A. ornatus, e Rhizopus stolonifer. Dois sorotipos diferentes de S. aureus e E. coli foram usados. Os resultados do método de difusão em ágar mostraram a resposta dependente da dose de extratos de plantas contra cepas de bactérias e fungos, enquanto alguns organismos foram considerados resistentes, e.g. E. coli (1), S. sonnei, A. terreus e R. stolonifer. A maior atividade antibacteriana foi registrada em 17.000 ± 1.732 de 100 mg/mL de extratos metanólicos de folhas contra S. pyogenes, enquanto a atividade da maioria dos patógenos diminuiu após 24 h de incubação. A maior atividade antifúngica foi relatada em 11,833 ± 1,0 contra A. ornatus a 50 mg/mL após 48 h do período de incubação. Esses achados experimentais endossam o uso de S. alba em formulações etnofarmacológicas e sugerem o uso de extratos metanólicos da referida planta para o desenvolvimento de fármacos que controlem a proliferação de doenças resistentes que causam micróbios patogênicos.
Assuntos
Salix , Antifúngicos/farmacologia , Aspergillus , Rhizopus , Staphylococcus aureus , Extratos Vegetais/farmacologia , Testes de Sensibilidade Microbiana , Metanol , Escherichia coli , Antibacterianos/farmacologiaRESUMO
Contamination by Aspergillus sp. and the accumulation of its mycotoxins in food and beverages have a high impact on human health and food safety. This investigation inquires the ability of brewer's yeasts discarded after fermentation (brewing fermentation residue, BFR) to synthesize bioactive compounds and to biocontrol Aspergillus sp. BFRs of Saccharomyces cerevisiae MBELGA62 and Pichia kudriavzevii MBELGA61 proved to have bacteriostatic properties and to be efficient in fungal growth reduction, decreasing the growth rate of Aspergillus flavus and Aspergillus parasiticus up to 37.8% and 42.5%, respectively. Fungal mycelium degradation along with absentia of conidia was detected near the yeast inoculum. Moreover, the yeasts synthesize volatile bioactive compounds that extend Aspergillus sp. lag phase above 100% and decrease fungal growth rates from 20% towards 44%, along with the complete inhibition of conidia synthesis. These results indicate the potential of this residue to be used in biocontrol applications in the food industry.
RESUMO
Staphylococcus aureus is considered the most common opportunistic pathogen in humans, capable of forming biofilm, increasing the chances of antibiotic resistance and causes several chronic diseases. Biodiversity is a source of inspiration in the search for new agents against these microorganisms. Hitherto, the efficacy of Hypericum sp. extracts as an antibacterial agent has already been demonstrated against Gram-positive and Gram-negative bacteria. In this study, we observed that until 4 µg/mL, the Hypericum brasiliense extract showed bactericidal activity against a clinical multidrug-resistant S. aureus strain (HU25) and also inhibited biofilm formation at 1/2xMIC (confirmed by SEM) and 1/4xMIC. The extract was also proportionally active against 6 h-preformed biofilm to its concentration (1/2xMIC, 1/4xMIC, p value ≤ 0.05). These promising results make Hypericum brasiliense extract a strong candidate to treat S. aureus infections, including anti-biofilm therapy.
Assuntos
Hypericum , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Antibacterianos/farmacologia , Biofilmes , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Humanos , Testes de Sensibilidade Microbiana , Extratos Vegetais/farmacologia , Staphylococcus aureusRESUMO
Mastitis causes significant economic losses to the dairy cattle industry. The present study aimed to evaluate the antibacterial properties of 39 heterocyclic derivatives (1,3-thiazoles and 4-thiazolidinones) against clinical mastitis isolates from dairy cows. Milk samples were collected from cows with clinical mastitis and the bacterial species were identified by PCR. Antibacterial activity was assessed using the broth microdilution method. First, 39 heterocyclic compounds were tested against four bacterial isolates (Staphylococcus aureus, Streptococcus agalactiae, Corynebacterium bovis and Escherichia coli) randomly chosen from those recovered from the milk samples (Study 1). Subsequently, the compounds with the strongest antibacterial activity were tested against all the bacterial isolates recovered from the milk samples (Study 2). 1,3-thiazoles showed the strongest antibacterial activity, specially compounds 30 and 38, which also showed bactericidal properties according to their minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values. Corynebacterium spp. and Enterobacteriaceae isolates were the most susceptible to compounds 30 and 38. Compounds 30 and 38 are promising targets for new antimicrobial agents.(AU)
A mastite causa significativas perdas econômicas à indústria leiteira bovina. O presente estudo teve como objetivo avaliar as propriedades antibacterianas de 39 derivados heterocíclicos (1,3-tiazóis e 4-tiazolidinonas) contra isolados clínicos de mastite em vacas leiteiras. Amostras de leite foram coletadas de vacas com mastite clínica e as espécies bacterianas isoladas foram identificadas por PCR. A atividade antibacteriana foi avaliada pelo método de microdiluição em caldo. Primeiramente, os 39 compostos heterocíclicos foram testados contra quatro isolados bacterianos (Staphylococcus aureus, Streptococcus agalactiae, Corynebacterium bovis e Escherichia coli) escolhidos aleatoriamente dentre os recuperados das amostras de leite (Estudo 1). Posteriormente, compostos com atividade antibacteriana mais forte foram testados contra todos os isolados bacterianos recuperados das amostras de leite (Estudo 2). Os compostos 1,3-tiazóis apresentaram a maior atividade antibacteriana, principalmente os compostos 30 e 38, que também apresentaram propriedades bactericidas de acordo com seus valores de concentração inibitória mínima (CIM) e concentração bactericida mínima (CBM). Os isolados Corynebacterium spp. e Enterobacteriaceae foram os mais suscetíveis aos compostos 30 e 38. Os compostos 30 e 38 mostraram-se promissores como novos agentes antimicrobianos.(AU)
Assuntos
Animais , Bovinos , Tiazóis/administração & dosagem , Mastite/imunologia , Antibacterianos , Staphylococcus aureus , Streptococcus agalactiae , Bovinos/microbiologiaRESUMO
ABSTRACT: Mastitis causes significant economic losses to the dairy cattle industry. The present study aimed to evaluate the antibacterial properties of 39 heterocyclic derivatives (1,3-thiazoles and 4-thiazolidinones) against clinical mastitis isolates from dairy cows. Milk samples were collected from cows with clinical mastitis and the bacterial species were identified by PCR. Antibacterial activity was assessed using the broth microdilution method. First, 39 heterocyclic compounds were tested against four bacterial isolates (Staphylococcus aureus, Streptococcus agalactiae, Corynebacterium bovis and Escherichia coli) randomly chosen from those recovered from the milk samples (Study 1). Subsequently, the compounds with the strongest antibacterial activity were tested against all the bacterial isolates recovered from the milk samples (Study 2). 1,3-thiazoles showed the strongest antibacterial activity, specially compounds 30 and 38, which also showed bactericidal properties according to their minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values. Corynebacterium spp. and Enterobacteriaceae isolates were the most susceptible to compounds 30 and 38. Compounds 30 and 38 are promising targets for new antimicrobial agents.
RESUMO: A mastite causa significativas perdas econômicas à indústria leiteira bovina. O presente estudo teve como objetivo avaliar as propriedades antibacterianas de 39 derivados heterocíclicos (1,3-tiazóis e 4-tiazolidinonas) contra isolados clínicos de mastite em vacas leiteiras. Amostras de leite foram coletadas de vacas com mastite clínica e as espécies bacterianas isoladas foram identificadas por PCR. A atividade antibacteriana foi avaliada pelo método de microdiluição em caldo. Primeiramente, os 39 compostos heterocíclicos foram testados contra quatro isolados bacterianos (Staphylococcus aureus, Streptococcus agalactiae, Corynebacterium bovis e Escherichia coli) escolhidos aleatoriamente dentre os recuperados das amostras de leite (Estudo 1). Posteriormente, compostos com atividade antibacteriana mais forte foram testados contra todos os isolados bacterianos recuperados das amostras de leite (Estudo 2). Os compostos 1,3-tiazóis apresentaram a maior atividade antibacteriana, principalmente os compostos 30 e 38, que também apresentaram propriedades bactericidas de acordo com seus valores de concentração inibitória mínima (CIM) e concentração bactericida mínima (CBM). Os isolados Corynebacterium spp. e Enterobacteriaceae foram os mais suscetíveis aos compostos 30 e 38. Os compostos 30 e 38 mostraram-se promissores como novos agentes antimicrobianos.
RESUMO
Mastitis causes significant economic losses to the dairy cattle industry. The present study aimed to evaluate the antibacterial properties of 39 heterocyclic derivatives (1,3-thiazoles and 4-thiazolidinones) against clinical mastitis isolates from dairy cows. Milk samples were collected from cows with clinical mastitis and the bacterial species were identified by PCR. Antibacterial activity was assessed using the broth microdilution method. First, 39 heterocyclic compounds were tested against four bacterial isolates (Staphylococcus aureus, Streptococcus agalactiae, Corynebacterium bovis and Escherichia coli) randomly chosen from those recovered from the milk samples (Study 1). Subsequently, the compounds with the strongest antibacterial activity were tested against all the bacterial isolates recovered from the milk samples (Study 2). 1,3-thiazoles showed the strongest antibacterial activity, specially compounds 30 and 38, which also showed bactericidal properties according to their minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values. Corynebacterium spp. and Enterobacteriaceae isolates were the most susceptible to compounds 30 and 38. Compounds 30 and 38 are promising targets for new antimicrobial agents.(AU)
A mastite causa significativas perdas econômicas à indústria leiteira bovina. O presente estudo teve como objetivo avaliar as propriedades antibacterianas de 39 derivados heterocíclicos (1,3-tiazóis e 4-tiazolidinonas) contra isolados clínicos de mastite em vacas leiteiras. Amostras de leite foram coletadas de vacas com mastite clínica e as espécies bacterianas isoladas foram identificadas por PCR. A atividade antibacteriana foi avaliada pelo método de microdiluição em caldo. Primeiramente, os 39 compostos heterocíclicos foram testados contra quatro isolados bacterianos (Staphylococcus aureus, Streptococcus agalactiae, Corynebacterium bovis e Escherichia coli) escolhidos aleatoriamente dentre os recuperados das amostras de leite (Estudo 1). Posteriormente, compostos com atividade antibacteriana mais forte foram testados contra todos os isolados bacterianos recuperados das amostras de leite (Estudo 2). Os compostos 1,3-tiazóis apresentaram a maior atividade antibacteriana, principalmente os compostos 30 e 38, que também apresentaram propriedades bactericidas de acordo com seus valores de concentração inibitória mínima (CIM) e concentração bactericida mínima (CBM). Os isolados Corynebacterium spp. e Enterobacteriaceae foram os mais suscetíveis aos compostos 30 e 38. Os compostos 30 e 38 mostraram-se promissores como novos agentes antimicrobianos.(AU)
Assuntos
Animais , Bovinos , Tiazóis/administração & dosagem , Mastite/imunologia , Antibacterianos , Staphylococcus aureus , Streptococcus agalactiae , Bovinos/microbiologiaRESUMO
Following the appearance of several antimicrobial agents to control the spread of infections, two major challenges have emerged: (i) the occurrence and blowout of multiresistant bacteria and the increase of chronic diseases and (ii) difficult-to-eradicate infections. In this study, we tested five benzoylthiourea derivatives for their ability to inhibit and stop bacterial growth and evaluated the possible influence of 1,2,4-triazolyl-benzoylthiourea derivative 4 on the formation and eradication of Staphylococcus aureus biofilms. Benzoylthiourea derivatives 4, 6, 10, 11 and 13 were obtained in one or two steps with low cost and subjected to tests to identify their minimum inhibitory concentration (MIC) and minimum bactericidal concentration. In vitro tests were also performed to assess their effects on biofilm formation and in preformed biofilms and scanning electron microscopy was used to visualize the effects on biofilm formation. The 1,2,4-triazolyl-benzoylthiourea derivative 4 showed bacteriostatic activity against the S. aureus HU25 clinical strain with an MIC of 16 µg ml-1 , which is below the toxic concentration (at 2500 µg ml-1 , 62·25% of the cells remained viable). Compound 4 also effectively prevented biofilm formation at the three subinhibitory concentrations tested (1/2 MIC, 1/4 MIC and 1/8 MIC) as confirmed by scanning electron microscopy. For breakdown of formed biofilms, the main influence was at a subinhibitory concentration (1/2 MIC). These findings make compound 4 a strong candidate for studies on the development of new antimicrobial and antibiofilm agents.
Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Tioureia/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Humanos , Testes de Sensibilidade Microbiana , Plâncton/efeitos dos fármacos , Plâncton/crescimento & desenvolvimento , Plâncton/fisiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus aureus/fisiologia , Tioureia/químicaRESUMO
Antimicrobial peptides (AMPs) have been recognised as a significant therapeutic option for mitigating resistant microbial infections. It has been found recently that Plasmodium falciparum-derived, 20 residue long, peptide 35409 had antibacterial and haemolytic activity, making it an AMP having reduced selectivity, and suggesting that it should be studied more extensively for obtaining new AMPs having activity solely targeting the bacterial membrane. Peptide 35409 was thus used as template for producing short synthetic peptides (<20 residues long) and evaluating their biological activity and relevant physicochemical characteristics for therapeutic use. Four of the sixteen short peptides evaluated here had activity against E. coli without any associated haemolytic effects. The 35409-1 derivative (17 residues long) had the best therapeutic characteristics as it had high selectivity for bacterial cells, stability in the presence of human sera, activity against E. coli multiresistant clinical isolates and was shorter than the original sequence. It had a powerful membranolytic effect and low potential for inducing resistance in bacteria. This peptide's characteristics highlighted its potential as an alternative for combating infection caused by E. coli multiresistant bacteria and/or for designing new AMPs.
RESUMO
Protecting soil fertility represents a fundamental effort of sustainable development. In this study we investigate how different altitudes affect soil microbial biomass carbon (MBC) and soil organic carbon (SOC), and their ratio, MBC/SOC in Hyperalic Alisol. MBC and SOC are well established and widely accepted microbial quotients in soil science. Our work hypothesis was that a decrease in MBC and SOC should be observed at higher altitudes. This initial assumption has been verified by our measurements, being attributed to the increase in MBC and SOC at low altitudes. Our approach should contribute to the better understanding of MBC and SOC distribution in soil and changes in MBC/SOC at various altitudes in the region.
Assuntos
Altitude , Biomassa , Carbono/análise , Microbiologia do Solo , Solo/química , EquadorRESUMO
Stem-end rot caused by Lasiodiplodia theobromae is one of the most devastating diseases of papaya in northeastern Brazil. It is most effectively controlled by applications of fungicides, including site-specific fungicides at risk for resistance development. This study investigated the molecular mechanisms of reduced sensitivity to the QoI fungicide azoxystrobin and resistance to the MBC fungicide thiophanate-methyl in L. theobromae from Brazilian orchards. The EC50 values for azoxystrobin in sixty-four isolates ranged from 0.36⯵g/ml to 364.24⯵g/ml and the frequency distribution of EC50 values formed a multimodal curve, indicating reduced sensitivity to azoxystrobin. In detached fruit assays reduced sensitive isolates were not controlled as effectively as sensitive isolates at lowest label rate. Partial fragments were obtained from target genes ß-tubulin (751â¯bp) and Cytb (687â¯bp) of isolates resistant to thiophanate-methyl and reduced sensitivity to azoxystrobin. Sequence analysis of the ß-tubulin fragment revealed a mutation corresponding to E198K in all thiophanate-methyl-resistant isolates, while reduced sensitivity to axoxystrobin was not attributable to Cytb gene alterations. The target gene-based mechanism conferring resistance to thiophanate-methyl will likely be stable even if selection pressure subsides. However, the mechanism conferring reduced sensitivity to azoxystrobin is not based on target gene modifications and thus may not be as stable as other genotypes with mutations in Cytb gene.
Assuntos
Ascomicetos , Carica , Fungicidas Industriais , Brasil , Farmacorresistência Fúngica , Pirimidinas , Estrobilurinas , TiofanatoRESUMO
O pequi é uma fruta nativa do Cerrado brasileiro que apresenta elevado teor de compostos antioxidantes e pode apresentar ação antimicrobiana. Dessa forma, objetivou-se com o presente trabalho avaliar a atividade bacteriostática e bactericida do extrato da casca do pequi. Das cepas estudadas 5 são padrões cedidos pela FIOCRUZ e 5 são bactérias de alta resistência a antimicrobianos isoladas de carne e frango. Foi determinada a concentração inibitória mínima (CIM) e concentração bactericida mínima do extrato da casca do pequi. O extrato da casca do pequi apresenta atividade antimicrobiana frente a bactérias patogênicas e deteriorantes. C. jejuni e C. colisão as mais sensíveis. S. aureus apresentou tolerância. E. coli O157:H7 e E. coli são menos sensíveis. O resíduo do pequi é uma potencial e importante fonte de antimicrobianos naturais.(AU)
Assuntos
Ericales , Extratos Vegetais/análise , Extratos Vegetais/uso terapêutico , Antibacterianos/análise , Resíduos de Alimentos , Técnicas Bacteriológicas/análiseRESUMO
O pequi é uma fruta nativa do Cerrado brasileiro que apresenta elevado teor de compostos antioxidantes e pode apresentar ação antimicrobiana. Dessa forma, objetivou-se com o presente trabalho avaliar a atividade bacteriostática e bactericida do extrato da casca do pequi. Das cepas estudadas 5 são padrões cedidos pela FIOCRUZ e 5 são bactérias de alta resistência a antimicrobianos isoladas de carne e frango. Foi determinada a concentração inibitória mínima (CIM) e concentração bactericida mínima do extrato da casca do pequi. O extrato da casca do pequi apresenta atividade antimicrobiana frente a bactérias patogênicas e deteriorantes. C. jejuni e C. colisão as mais sensíveis. S. aureus apresentou tolerância. E. coli O157:H7 e E. coli são menos sensíveis. O resíduo do pequi é uma potencial e importante fonte de antimicrobianos naturais.
Assuntos
Antibacterianos/análise , Ericales , Extratos Vegetais/análise , Extratos Vegetais/uso terapêutico , Resíduos de Alimentos , Técnicas Bacteriológicas/análiseRESUMO
Innovative therapeutic heterocycles having precisely thiadiazolyl-pyranopyrazole fragments were prepared by using the ecofriendly synthetic route. Entire compounds formed in quantitative yields. All the composites tested for their antimicrobial effectiveness against four microbial, two beneficial fungi's and accurately measured the minimum inhibitory concentrations (MIC and MBC/MFC), along with some initial structure activity relationships (SARs) also discussed. From the biological outcomes, the motif 6f provided an outstanding activity against all six pathogens. The possible presence of a nitro substituent on this composite may undoubtedly enhance the activity. In addition, amalgams 6d, 6g and 6l displayed promising antimicrobial results. This may be justified to the presence of electron capture group attached to the benzene ring, while the combinations 6j and 6k were zero effect towards all bacterial strains. The other compounds were excellent to low antimicrobial efficiency. The intriguing point was observed that all the active compounds had in common immense antibacterial effectiveness on Gram-negative bacteria than Gram-positive one and more antifungal activity on A. niger compare to other fungus. All things considered and suggested that this outstanding green synthetic approach is used to develop biological active compounds. On top of that, biological results confirmed that these biologically energetic motifs suitable for additional preclinical examine with the aim of standing novel innovative drugs.
Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Piranos/farmacologia , Pirazóis/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Antifúngicos/síntese química , Antifúngicos/química , Aspergillus flavus/efeitos dos fármacos , Aspergillus niger/efeitos dos fármacos , Bacillus subtilis/efeitos dos fármacos , Bentonita/química , Escherichia coli/efeitos dos fármacos , Química Verde/métodos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Proteus vulgaris/efeitos dos fármacos , Piranos/síntese química , Piranos/química , Pirazóis/síntese química , Pirazóis/química , Staphylococcus aureus/efeitos dos fármacos , Relação Estrutura-AtividadeRESUMO
Objective: The long-term success of root canal treatment is ultimately related to the effective debridement and disinfection of the root canal system. Hence, the irrigants play an important role in achieving the good penetrability and bactericidal activity. The present study was mainly aimed at evaluating the invitro antimicrobial efficacy of Novel Ethanolic Extract of Morinda Citrifolia by agar well diffusion and broth dilution methods. Material and methods: The antibacterial effect of Ethanolic Extract of Morinda Citrifolia was investigated against Enterococcus Faecalis (E. Faecalis). Agar well diffusion and broth dilution methods were used to determine the Minimal Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) Results: The MIC of Ethanolic Extract of Morinda Citrifolia extract was found to be 12.5 mg/ml and the MBC was found to be 25 mg/ml Conclusion: Novel Ethanolic Extract of Morinda Citrifolia possess antimicrobial activity against E.Faecalis. But still, future studies are needed. (AU)
Objetivo: O sucesso a longo prazo do tratamento de canais radiculares está intimamente relacionada com a efi cácia do debridamento e desinfecção do Sistema do canal radicular. Consequentemente, os irrigantes têm um importante papel na capacidade de penetração e atividade bactericida. O presente estudo teve como objetivo principal a avaliação in vitro da efi cácia antimicrobiana do novo extrato etanólico de Morinda Citrifolia por meio dos métodos de difusão em ágar ou de diluição em caldo. Material e métodos: O efeito antibacteriano do extrato etanólico de Morinda Citrifolia foi investigado contra Enterococcus Faecalis (E. Faecalis). Os métodos de diluição em ágar e de diluição em caldo foram usados para determinar a concentração inibitória minima (MIC) e concentração bactericida minima (MBC). Resultados: O MIC do extrato etanólico de Morinda Citrifolia foi obtido na concentração de 12.5mg/ml e a MBC foi de 25mg/ml Conclusão: O novo extrato etanólico de Morinda Citrifolia apresenta atividade antimicrobiana contra E.Faecalis. Porém, futuros estudos são necessários. (AU)
Assuntos
Irrigantes do Canal Radicular , Morinda , Cavidade Pulpar , EndodontiaRESUMO
Trisubstituted thiazoles were synthesized and studied for their antimicrobial activity and supported by theoretical calculations. In addition, MIC, MBC and MFC were also tested. Moreover, the present study was analyzed to scrutinize comprehensive structure-activity relationships. In fact, LUMO orbital energy and orbital orientation was reliable to explain their antibacterial and antifungal assay. Amongst the tested compounds, tri-methyl-substituted thiazole compound showed higher antimicrobial activity and low MIC value due to highest LUMO energy.
Assuntos
Antibacterianos/síntese química , Antibacterianos/farmacologia , Antifúngicos/síntese química , Antifúngicos/farmacologia , Desenho de Fármacos , Tiazóis/síntese química , Tiazóis/farmacologia , Antibacterianos/química , Antifúngicos/química , Aspergillus flavus/efeitos dos fármacos , Aspergillus niger/efeitos dos fármacos , Bactérias/efeitos dos fármacos , Técnicas de Química Sintética , Modelos Moleculares , Conformação Molecular , Eletricidade Estática , Relação Estrutura-Atividade , Tiazóis/químicaRESUMO
RESUMO O objetivo deste estudo foi pesquisar o efeito antimicrobiano in vitro do extrato hidroalcóolico das folhas Tradescantia pallida Munt conhecida como Taboquinha roxa. Foram realizados testes em meio sólido, onde não observou qualquer halo de inibição, e o método de microdiluição, em que os resultados foram expressivos, com determinação da Concentração Inibitória Mínima (CIM) e Concentração Bactericida Mínima (CBM), com resultados em diferentes concentrações. Foram utilizadas cepas padrão de bactérias Gram positivas e Gram negativas. De acordo com os resultados, sugere-se que essa planta apresenta um potencial antimicrobiano.
ABSTRACT The aim of this study was to investigate the in vitro antimicrobial effect of the hydroalcoholic extract of the Tradescantia pallida Munt leaves,known as Taboquinha roxa. The tests were both conducted on solid mean, where it was not observed any zone of inhibition, and by the micro dilution method, in which the results of the Minimum Inhibitory Concentration (MIC) and the Minimum Bactericidal Concentration (MBC) were significant and related with the different concentrations. Standard strains of bacteria type Gram positive and Gram negative were employed. According to the results, this plant has an antimicrobial potential.
Assuntos
Tradescantia/anatomia & histologia , Anti-Infecciosos/análise , Testes de Sensibilidade Microbiana , Bactérias Gram-Negativas/classificação , Bactérias Gram-Positivas/classificaçãoRESUMO
Silver nanoparticles (AgNPs) have been shown great interest because of their potential antibacterial effect. Recently, this has been increased due to resistance in some pathogenic bacteria strains to conventional antibiotics, which has initiated new studies to search for more effective treatments against resistant microorganisms. For these reasons, AgNPs have become an important approach for applications in nanobiotechnology in the development of antibiotic treatment of different bacterial infections. This study was aimed at synthesizing AgNPs using cysteine as a reducer agent and cetyl-tri-methyl-ammonium bromide as a stabilizer in order to obtain more efficient treatment against the pathogen bacteria Escherichia coli O157:H7. These AgNPs were characterized through UV-Vis spectroscopy, transmission electron microscopy, and dynamic light scattering. From these analyses, formation of spherical nanoparticles with an average size of 55 nm was confirmed. Finally, minimal inhibitory concentration (MIC) and minimal bactericide concentration (MBC) of these AgNPs against pathogenic strains E. coli O157:H7 and methicillin-resistant Staphylococcus aureus (MRSA) were determined in both solid and liquid media. MIC and MBC values were around 0.25 µg/mL and 1 µg/mL, respectively. These parameters were comparable to those reported in the literature and were even more effective than other synthesized AgNPs.