scholarly journals Actividad antimicrobiana de extractos hidroalcohólicos de hojas de dos variedades de Mangifera indica L

Ciencia Unemi ◽  
2020 ◽  
Vol 13 (32) ◽  
pp. 69-77
Author(s):  
Celeste Carrillo-Tomalá ◽  
Raúl Díaz-Torres ◽  
Katherine Guerra-Guamán ◽  
Andrés Román-Salmerón
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Salmonella Typhimurium ◽  
Enterococcus Faecalis ◽  
Mangifera Indica

El objetivo de este trabajo fue evaluar la actividad antimicrobiana de extractos hidroalcohólicos (90% y 50%) de la variedad Tommy Atkins y extracto hidroalcohólico (50%) de la variedad Edward, seleccionados por su alto contenido de compuestos fenólicos, anteriormente publicado. Los extractos fueron obtenidos por maceración, digestión y ultrasonido. La actividad antimicrobiana se evalúo mediante los métodos Kirby Bauer y Kirby Bauer modificado; las cepas utilizadas fueron Pseudomona aeuroginosa (ATCC 27853), Staphylococcus aureus (ATCC 29213), Salmonella Typhimurium (ATCC 14028), Escherichia coli (ATCC 25922) y Enterococcus faecalis (ATCC 29212), ajustándose las suspensiones a turbidez 0.5 en escala McFarland.  La mayor actividad antimicrobiana se evidencia frente a P. aeruginosa y S. aureus; los extractos de la variedad Tommy Atkins mostraron mayor actividad antimicrobiana, encontrándose halos de inhibición entre 10 y 15 mm según la bacteria.  El método Kirby Bauer modificado mostró mayor efectividad. Se concluye que todas las cepas estudiadas presentaron sensibilidad frente a los extractos, siendo S. aureus y P. aeruginosa las más sensibles.

scholarly journals Caracterización química y actividad antibacteriana del aceite esencial de Mangifera indica L. de tres regiones de Venezuela

2019 ◽  
Vol 48 (3) ◽  
pp. 13-18
Author(s):  
Rosa Aparicio zambrano ◽  
Judith Velasco Carrillo ◽  
Rafael Paredes Uzcategui ◽  
Luis Rojas Fermín
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Klebsiella Pneumoniae ◽  
Enterococcus Faecalis ◽  
Mangifera Indica

Los aceites esenciales (AE) de las hojas de Mangifera indica L. recolectadas en los estados Mérida (M), Barinas (B) y Portuguesa (P), Venezuela, fueron obtenidos por el método de hidrodestilación, utilizando la trampa de Clevenger, obteniéndose 0,1 mL (0,0025%), 1,4 mL (0,035%) y 1,0 mL (0,025%), respectivamente. Los AE se caracterizaron por el método de cromatografía de gases acoplado a espectrometría de masas (CG/EM), se identificaron 30 compuestos en la muestra recolectada en M, 24 en B y 14 en P, siendo los mayoritarios en M: β-selineno (22,56%), α-gurjuneno (14,66%), β-cariofileno (10,40%), en B: β-cariofileno (36,32%), α-humuleno (22,71%), α-gurjuneno (21,43%) y en P: β-cariofileno (36,07%), α-gurjuneno (22,55%) y α-humuleno (21,24%). Debido al rendimiento, solo se determinó la actividad antibacteriana en los AE de B  y P, por el método de difusión en agar con discos, frente a bacterias de referencia internacional (Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 23357 y Pseudomonas aureginosa ATCC 27853). Ambos AE inhibieron el desarrollo de S. aureus y E. faecalis con una concentración inhibitoria mínima de 200 µL/mL y 300 µL/mL, respectivamente. Este es el primer estudio comparativo y actividad antibacteriana del aceite esencial obtenido de las hojas de M. indica L. de tres regiones de Venezuela.

The In vitro Evaluation of the Antimicrobial Activity of Quercus robur L. Methanolic and Aqueous Leaves’ Extracts, from the Algerian High Plateaus Against some Uropathogenic Microbial Strains

2019 ◽  
Vol 18 (5) ◽  
pp. 262-274
Author(s):  
E. Benyagoub ◽  
N. Nabbou ◽  
S. Boukhalkhel ◽  
I. Dehini
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Candida Albicans ◽  
Enterococcus Faecalis ◽  
Fusidic Acid ◽  
Quercus Robur ◽  
Diffusion Method ◽  
Phytochemical Analysis ◽  
Microbial Strains

The medicinal value of the plants is due to their chemical components that bring a definite physiological action on the human body to prevent the diseases. In this work, we investigated the antimicrobial activity of leaves’ extracts of Quercus robur L., collected from the Algerian upper highlands, on ten bacterial strains and one fungal strain known to be pathogenic. First, we performed a qualitative phytochemical analysis, and second, antimicrobial activity tests performed by agar diffusion method (disc and well) with the determination of MIC by broth macro-dilution method. Given the results, it appears that obtained macerates of Quercus robur L. were rich in bioactive phytoconstituents such as alkaloids, anthraquinones, saponins, tannins, and other components. The yield of aqueous and methanolic macerates of leaves was 8.5 ± 1.41 and 22.4 ± 4.36%, respectively. The bacterial resistance was relatively important to several antibiotics, namely, ampicillin, amoxicillin + clavulanic acid for strains of Escherichia coli and Salmonella sp. However, Staphylococcus aureus strains were resistant to fusidic acid, penicillin, and oxacillin; while Enterococcus faecalis was resistant to fusidic acid, penicillin, oxacillin, and ticarcillin. The antibacterial activity of the macerates toward tested microbial strains showed that the aqueous and methanolic macerates of the leaves were proportional to the tested concentration and active not only against Gram-positive and Gram-negative bacteria but also on the fungal species Candida albicans. The estimated MIC for Escherichia coli, Enterococcus faecalis, and Staphylococcus aureus was in the order of 10 mg/mL, which seems more effective than toward Salmonella sp., Klebsiella pneumoniae, Pseudomonas aeruginosa, and Candida albicans which were in the order of 30 mg/mL. These preliminary results confirm that the part of the studied plant had a very good antimicrobial activity that was proportional to the serial concentrations of the tested extracts.

scholarly journals Urinary Excretion and Bactericidal Activities of Gemifloxacin and Ofloxacin after a Single Oral Dose in Healthy Volunteers

2001 ◽  
Vol 45 (12) ◽  
pp. 3524-3530 ◽  
Author(s):  
Christoph K. Naber ◽  
Michaela Hammer ◽  
Martina Kinzig-Schippers ◽  
Christian Sauber ◽  
Fritz Sörgel ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Urinary Tract ◽  
Urinary Excretion ◽  
Enterococcus Faecalis ◽  
Urinary Tract Infections ◽  
Parent Drug ◽  
Oral Dosage ◽  
Tract Infections ◽  
Cumulative Excretion

ABSTRACT In a randomized crossover study, 16 volunteers (8 men, 8 women) received single oral doses of 320 mg of gemifloxacin and 400 mg of ofloxacin on two separate occasions in the fasting state to assess the urinary excretion and urinary bactericidal titers (UBTs) at intervals for up to 144 h. Ofloxacin showed higher concentrations in urine compared with those of gemifloxacin. The median (range) cumulative excretion of gemifloxacin was 29.7% (8.4 to 48.7%) of the parent drug administered, and median (range) cumulative excretion of ofloxacin was 84.3% (46.5 to 95.2%) of the parent drug administered. The UBTs, i.e., the highest twofold dilutions (with antibiotic-free urine as the diluent) of urine that were still bactericidal, were determined for a reference strain and nine uropathogens for which the MICs of gemifloxacin and ofloxacin were as follows:Escherichia coli ATCC 25922, 0.016 and 0.06 μg/ml, respectively; Klebsiella pneumoniae, 0.03 and 0.06 μg/ml, respectively; Proteus mirabilis, 0.125 and 0.125 μg/ml, respectively; Escherichia coli, 0.06 and 0.5 μg/ml, respectively; Pseudomonas aeruginosa, 1 and 4 μg/ml, respectively; Staphylococcus aureus, 0.008 and 0.25 μg/ml, respectively; Enterococcus faecalis, 0.06 and 2 μg/ml, respectively;Staphylococcus aureus, 0.25 and 4 μg/ml, respectively;Enterococcus faecalis, 0.5 and 32 μg/ml, respectively; and Staphylococcus aureus, 2 and 32 μg/ml, respectively. Generally, the UBTs for gram-positive uropathogens were higher for gemifloxacin than for ofloxacin and the UBTs for gram-negative uropathogens were higher for ofloxacin than for gemifloxacin. According to the UBTs, ofloxacin-resistant uropathogens (MICs, ≥4 mg/liter) should also be considered gemifloxacin resistant. Although clinical trials have shown that gemifloxacin is effective for the treatment of uncomplicated urinary tract infections, whether an oral dosage of 320 mg of gemifloxacin once daily is also adequate for the treatment of complicated urinary tract infections has yet to be confirmed.

scholarly journals Autophagy—A Story of Bacteria Interfering with the Host Cell Degradation Machinery

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 110
Author(s):  
Anna K. Riebisch ◽  
Sabrina Mühlen ◽  
Yan Yan Beer ◽  
Ingo Schmitz
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Immune Response ◽  
Mycobacterium Tuberculosis ◽  
Listeria Monocytogenes ◽  
Salmonella Typhimurium ◽  
Innate Immune ◽  
Intracellular Pathogens ◽  
Response Mechanism ◽  
Pathogenic Escherichia Coli

Autophagy is a highly conserved and fundamental cellular process to maintain cellular homeostasis through recycling of defective organelles or proteins. In a response to intracellular pathogens, autophagy further acts as an innate immune response mechanism to eliminate pathogens. This review will discuss recent findings on autophagy as a reaction to intracellular pathogens, such as Salmonella typhimurium, Listeria monocytogenes, Mycobacterium tuberculosis, Staphylococcus aureus, and pathogenic Escherichia coli. Interestingly, while some of these bacteria have developed methods to use autophagy for their own benefit within the cell, others have developed fascinating mechanisms to evade recognition, to subvert the autophagic pathway, or to escape from autophagy.

scholarly journals ATIVIDADE ANTIMICROBIANA DE MICRORGANISMOS ISOLADOS DE GRÃOS DE KEFIR

2018 ◽  
Vol 19 (0) ◽  
Author(s):  
Priscila Alves Dias ◽  
Daiani Teixeira Silva ◽  
Cláudio Dias Timm
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Salmonella Typhimurium ◽  
Salmonella Enterica ◽  
Escherichia Coli O157 ◽  
E Coli

Resumo Kefir é o produto da fermentação do leite pelos grãos de kefir. Esses grãos contêm uma mistura simbiótica de bactérias e leveduras imersas em uma matriz composta de polissacarídeos e proteínas. Muitos benefícios à saúde humana têm sido atribuídos ao kefir, incluindo atividade antimicrobiana contra bactérias Gram positivas e Gram negativas. A atividade antimicrobiana de 60 microrganismos isolados de grãos de kefir, frente à Escherichia coli O157:H7, Salmonella enterica subsp. enterica sorotipos Typhimurium e Enteritidis, Staphylococcus aureus e Listeria monocytogenes, foi estudada através do teste do antagonismo. A ação antimicrobiana dos sobrenadantes das bactérias ácido-lácticas que apresentaram atividade no teste do antagonismo foi testada. O experimento foi repetido usando sobrenadantes com pH neutralizado. Salmonella Typhimurium e Enteritidis sobreviveram por 24 horas no kefir em fermentação. E. coli O157:H7, S. aureus e L. monocytogenes foram recuperados até 72 horas após o início da fermentação. Todos os isolados apresentaram atividade antimicrobiana contra pelo menos um dos patógenos usados no teste do antagonismo. Sobrenadantes de 25 isolados apresentaram atividade inibitória e três mantiveram essa atividade com pH neutralizado. As bactérias patogênicas estudadas sobreviveram por tempo superior àquele normalmente utilizado para a fermentação do kefir artesanal, o que caracteriza perigo em potencial para o consumidor quando a matéria-prima não apresentar segurança sanitária. Lactobacillus isolados de grãos de kefir apresentam atividade antimicrobiana contra cepas de E. coli O157:H7, Salmonella sorotipos Typhimurium e Enteritidis, S. aureus e L. monocytogenes além daquela exercida pela diminuição do pH.

Antimicrobial Effects of Novel H2O2-Ag+ Complex on Membrane Damage to Staphylococcus aureus,Escherichia coli and Salmonella typhimurium

2021 ◽  
Author(s):  
Bing Han ◽  
Xiaoyu Han ◽  
Mengmeng Ren ◽  
Yilin You ◽  
Jicheng Zhan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Hydrogen Peroxide ◽  
Staphylococcus Aureus ◽  
Salmonella Typhimurium ◽  
Membrane Damage ◽  
Bactericidal Effect ◽  
E Coli ◽  
Bacterial Cell Membrane ◽  
Time Kill ◽  
Environmental Disinfection

Diseases caused by harmful microorganisms pose a serious threat to human health. Safe and environment-friendly disinfectants are, therefore, essential in preventing and controlling such pathogens. This study aimed to investigate the antimicrobial activity and mechanism of a novel hydrogen peroxide and silver (H 2 O 2 -Ag + ) complex (HSC) in combatting Staphylococcus aureus ATCC 29213, Escherichia coli O157:H7 NCTC 12900 and Salmonella typhimurium SL 1344. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values against S. aureus were found to be 0.014 % H 2 O 2 -3.125 mg/L Ag + , while 0.028 % H 2 O 2 -6.25 mg/L Ag + for both E. coli and S. typhimurium . Results of the growth curve assay and time-kill trial suggest that the HSC could inhibit the growth of the tested bacteria, as 99.9 % of viable cells were killed following treatment at the 1 MIC for 3 h. Compared with Oxytech D10 disinfectant (0.25 % H 2 O 2 -5 mg/L Ag + ), the HSC exhibited better antibacterial efficacy at a lower concentration (0.045 % H 2 O 2 -10 mg/L Ag + ). The mechanism of antibacterial action of HSC was found including the disruption of the bacterial cell membrane, followed by entry into the bacteria cell to reduce intracellular adenosine triphosphate (ATP) concentration, and inhibit the activity of antioxidases, superoxide dismutase (SOD) and catalase (CAT). The enhanced bactericidal effect of hydrogen peroxide combined with silver indicates a potential for its application in environmental disinfection, particularly in the food industry.

scholarly journals Atividade antibacteriana de extratos de folhas de Montrichardia linifera (Arruda) Schott (Araceae)

2015 ◽  
Vol 17 (4 suppl 3) ◽  
pp. 1142-1149 ◽  
Author(s):  
J.A.L MIRANDA ◽  
J.A. ROCHA ◽  
K.M. ARAÚJO ◽  
P.V. QUELEMES ◽  
S.J. MAYO ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Klebsiella Pneumoniae ◽  
Enterococcus Faecalis ◽  
Staphylococcus Epidermidis

RESUMO O uso de plantas medicinais no tratamento de doenças é uma estratégia antiga utilizada por praticamente todas as populações do mundo, e, embora novos antibióticos tenham sido desenvolvidos para o controle de micro-organismos infecciosos, às vezes são ineficazes. Diversos extratos de plantas medicinais têm efeitos antimicrobianos, principalmente quando associados à antibióticos de uso clínico, representando alternativa terapêutica para doenças infecciosas. Montrichardia linifera, conhecida popularmente como aninga, é espécie macrófita, aquática emergente de hábito herbáceo, pertencente a família Araceae e ocorre em áreas alagáveis. A utilidade farmacológica desta espécie é diversificada tendo sido relatada como cicatrizante, antirreumático, antidiurético e expectorante. Devido à relevância no campo etnofarmacológico, ampla utilização na medicina popular e escassez de trabalhos relacionados à atividade antibacteriana desta espécie, objetivou-se com este trabalho avaliar a atividade antibacteriana de extratos alcoólicos de folhas de Montrichardia linifera, coletadas na margem do rio Igaraçu, Parnaíba-PI. O extrato foi testado em oito cepas de bactérias: Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae e Pseudomonas aeruginosa. Foram utilizadas as técnicas de verificação da formação de halos de inibição e determinação das concentrações inibitórias e bactericidas mínimas. Os testes antibacterianos evidenciaram como principais resultados que o extrato metanólico seco (EMS), extrato metanólico fresco (EMF), e o extrato etanólico seco (EES), apresentaram ação antibacteriana, enquanto o extrato etanólico fresco (EEF) não apresentou atividade para as bactérias testadas. O EMS foi o mais eficiente, inibindo o crescimento bacteriano na concentração de 200 μg/mL para E. faecalis, 400 μg/mL para S. aureus, 400 μg/mL para S. epidermidis e 2.000 μg/mL para P. aeruginosa. O EMF obteve CIM de 2.000 μg/mL para E. faecalis e EES obteve CIM de 250 μg/mL para E. faecalis. Os resultados demonstraram que M. linifera constitui fonte eficiente de compostos bioativos antibacterianos. Os estudos sobre as propriedades farmacológicas de plantas da família Araceae são escassos, e os resultados deste trabalho são pioneiros em relação a atividade antibacteriana desta espécie.

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