scholarly journals In Vitro Bactericidal Activities of Daptomycin against Staphylococcus aureus and Enterococcus faecalis Are Not Mediated by Inhibition of Lipoteichoic Acid Biosynthesis

2003 ◽  
Vol 47 (8) ◽  
pp. 2682-2684 ◽  
Author(s):  
Valerie Laganas ◽  
Jeffrey Alder ◽  
Jared A. Silverman
Keyword(s):  
Staphylococcus Aureus ◽  
Enterococcus Faecalis ◽  
Mechanism Of Action ◽  
Lipoteichoic Acid ◽  
Acid Synthesis ◽  
Enterococcus Hirae ◽  
Macromolecular Synthesis ◽  
Acid Biosynthesis ◽  
Bactericidal Activities

ABSTRACT Previous studies have suggested that lipoteichoic acid biosynthesis inhibition is the mechanism of action of daptomycin. In this investigation, daptomycin inhibited all macromolecular synthesis in Staphylococcus aureus, Enterococcus faecalis, and Enterococcus hirae without kinetic or dose specificity for lipoteichoic acid. Daptomycin remained bactericidal in the absence of ongoing lipoteichoic acid synthesis. Inhibition of lipoteichoic acid synthesis is apparently not the mechanism of action of daptomycin in these pathogens.

ATIVIDADE ANTIMICROBIANA IN VITRO DO EXTRATO AQUOSO, HIDROALCOÓLICO E ALCOÓLICO DE FOLHAS DE ESPÉCIES DA FAMÍLIA LAMIACEAE

2018 ◽  
Vol 4 ◽  
Author(s):  
Karlynne Freire Mendonça ◽  
José Klauber Roger Carneiro ◽  
Maria Auxiliadora Silva Oliveira
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Enterococcus Faecalis ◽  
Streptococcus Pyogenes ◽  
Mentha Arvensis ◽  
Ocimum Gratissimum ◽  
Mueller Hinton ◽  
Plectranthus Amboinicus

Objetivos: avaliar a atividade antimicrobiana em extrato aquoso, hidroalcoólico e alcoólico das folhas de espécies da família Lamiaceae frente a bactérias de interesse. Método: Foram escolhidas quatro espécies: Ocimum gratissimum, Plectranthus amboinicus, Mentha arvensis e Plectranthus barbatus. A partir das folhas foram confeccionados os extratos aquoso, hidroalcoólico e alcoólico nas concentrações 100mg/mL, 50mg/mL e 25mg/mL. Foram selecionadas as bactérias Streptococcus pyogenes, Enterococcus faecalis, Staphylococcus aureus e Pseudomonas aeruginosa para os ensaios de antibiose em Ágar Mueller-Hinton. Resultados: P. barbatus, em seu extrato hidroalcoólico mostrou ativo nas três concentrações para bactéria S. aureus, e ainda foi ativo para P. aeruginosa, demonstrando no extrato alcoólico atividade frente as bactérias. Para M. arvensis e P. amboinicus, seus extratos hidroalcoólico e alcoólico apresentaram atividade para S. aureus. Conclusão: Sugere-se que as espécies em questão apresentem boa atividade antimicrobiana, sendo necessária a realização de mais estudos para melhor entender esse mecanismo.

scholarly journals Bacteriophage-derived CHAP domain protein, P128, kills Staphylococcus cells by cleaving interpeptide cross-bridge of peptidoglycan

Microbiology ◽  
2014 ◽  
Vol 160 (10) ◽  
pp. 2157-2169 ◽  
Author(s):  
Sudarson Sundarrajan ◽  
Junjappa Raghupatil ◽  
Aradhana Vipra ◽  
Nagalakshmi Narasimhaswamy ◽  
Sanjeev Saravanan ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Mechanism Of Action ◽  
Catalytic Domain ◽  
Antibiotic Sensitivity ◽  
High Sensitivity ◽  
Common Mechanism ◽  
Cross Bridge ◽  
Sensitivity Pattern

P128 is an anti-staphylococcal protein consisting of the Staphylococcus aureus phage-K-derived tail-associated muralytic enzyme (TAME) catalytic domain (Lys16) fused with the cell-wall-binding SH3b domain of lysostaphin. In order to understand the mechanism of action and emergence of resistance to P128, we isolated mutants of Staphylococcus spp., including meticillin-resistant Staphylococcus aureus (MRSA), resistant to P128. In addition to P128, the mutants also showed resistance to Lys16, the catalytic domain of P128. The mutants showed loss of fitness as shown by reduced rate of growth in vitro. One of the mutants tested was found to show reduced virulence in animal models of S. aureus septicaemia suggesting loss of fitness in vivo as well. Analysis of the antibiotic sensitivity pattern showed that the mutants derived from MRSA strains had become sensitive to meticillin and other β-lactams. Interestingly, the mutant cells were resistant to the lytic action of phage K, although the phage was able to adsorb to these cells. Sequencing of the femA gene of three P128-resistant mutants showed either a truncation or deletion in femA, suggesting that improper cross-bridge formation in S. aureus could be causing resistance to P128. Using glutathione S-transferase (GST) fusion peptides as substrates it was found that both P128 and Lys16 were capable of cleaving a pentaglycine sequence, suggesting that P128 might be killing S. aureus by cleaving the pentaglycine cross-bridge of peptidoglycan. Moreover, peptides corresponding to the reported cross-bridge of Staphylococcus haemolyticus (GGSGG, AGSGG), which were not cleaved by lysostaphin, were cleaved efficiently by P128. This was also reflected in high sensitivity of S. haemolyticus to P128. This showed that in spite of sharing a common mechanism of action with lysostaphin, P128 has unique properties, which allow it to act on certain lysostaphin-resistant Staphylococcus strains.

scholarly journals Efeito antimicrobiano do extrato de Cranberry sobre micro-organismos causadores de infecção urinária

2016 ◽  
Vol 11 (31) ◽  
pp. 113-122
Author(s):  
Carla Franco Porto Belmont Souza ◽  
Luiz Eduardo Souza da Silva Irineu ◽  
Renan Silva De Souza ◽  
Renato da Silva Teixeira ◽  
Ivina Sanches Pereira ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Klebsiella Pneumoniae ◽  
Enterococcus Faecalis ◽  
Proteus Mirabilis ◽  
Enterococcus Faecium ◽  
Vaccinium Macrocarpon ◽  
Mueller Hinton

A resistência microbiana tem se mostrado um problema de proporções mundiais, causando estado de morbidade e mortalidade em diversos pacientes. Em vista disso, tem crescido a busca por métodos alternativos naturais de profilaxia. A investigação clínica sugere que o Extrato de Cranberry está entre as melhores propostas de prevenção natural. O Cranberry (Vaccinium macrocarpon) é um fruto que tem crescido comercialmente pelo sabor e propriedades benéficas à saúde. Dentre as formas comercializadas estão: o suco, o chá e as cápsulas contendo o extrato seco. A ação desta planta está relacionada ao tratamento de doenças do trato urinário, por possuir substâncias que inibem a adesão bacteriana ao epitélio do trato urinário, dificultando sua proliferação e reprodução. Dentre todas as infecções relacionadas à assistência a saúde, a Infecção do Trato Urinário é a mais frequentemente associada a procedimentos invasivos. Se não for tratada, pode resultar em complicações como pielonefrite aguda, bacteremia e pionefrose. Portanto, cranberry pode ser uma nova alternativa para o combate das infecções uroepiteliais, por ser um produto natural de preço acessível, e com formas de comercialização diversificada, ao contrário dos antimicrobianos convencionais, que por sua vez são caros e podem acabar causando resistência nos micro-organismos. Este trabalho teve como objetivo avaliar in vitro a atividade antimicrobiana do extrato de Cranberry, adquirido em farmácia de manipulação, sobre 8 micro-organismos isolados de infecções urinárias. As cepas utilizadas, adquiridas da coleção da FIOCRUZ, foram: Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus mirabilis, Serratia marscecens, Staphylococcus aureus, Enterococcus faecalis e Enterococcus faecium. No estudo, foram utilizados o caldo Mueller Hinton (MH), Extrato de Cranberry e as bactérias patogênicas. O ensaio foi realizado em triplicata, com o uso de um controle de crescimento dos micro-organismos e o experimento para avaliação do crescimento bacteriano na presença do extrato. A turbidez foi medida com o auxílio de um espectrofotômetro, no comprimento de onda de 600 nm, antes e após 24 horas de incubação à 37 ºC. O procedimento forneceu a Densidade Ótica, do qual possibilitou a identificação da inibição microbiana. Para análise estatística foi utilizado o Teste t de Student. O Extrato de Cranberry apresentou atividade antimicrobiana sobre as bactérias Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, Serratia marscecens e Enterococcus faecalis (p < 0,05), confirmando seu efeito benéfico em infecções urinárias. No entanto, não teve efeito inibitório significativo sobre Pseudomonas aeruginosa, Proteus mirabilis e Enterococcus faecium (p > 0,05).

scholarly journals Chemical Composition and in Vitro Antibacterial Activity of the Essential Oil of Calycolpus Moritzianus (O. Berg) Burret from Mérida, Venezuela

2008 ◽  
Vol 3 (6) ◽  
pp. 1934578X0800300 ◽  
Author(s):  
Teresa Díaz ◽  
Flor D. Mora ◽  
Judith Velasco ◽  
Tulia Díaz ◽  
Luis B. Rojas ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Chemical Composition ◽  
Essential Oil ◽  
Enterococcus Faecalis ◽  
Chemical Constituents ◽  
Ms Analysis ◽  
In Vitro Antibacterial Activity

The chemical constituents of the essential oil obtained by hydrodistillation from the leaves of Calycolpus moritzianus (O. Berg) Burret, syn Psidium caudatum Mc Vaught, collected in November 2006 in Mérida State, Venezuela, were identified by GC-MS analysis. Thirty components (91.1% of the sample) were identified, of which the seven major ones were β-caryophyllene (21.9%), α-pinene (10.9%), viridiflorol (9.7%), β-selinene (6.1%), α-copaene (6.3%), α-selinene (5.3%) and γ-eudesmol (5.1%). The oil was found to have antibacterial activity against Staphylococcus aureus ATCC (6538) and Enterococcus faecalis ATCC (29212), with MIC values of 60 μg/mL and 180 μg/mL, respectively.

scholarly journals Persistence of Enterococcus faecalis in Aquatic Environments via Surface Interactions with Copepods

2005 ◽  
Vol 71 (5) ◽  
pp. 2756-2761 ◽  
Author(s):  
Caterina Signoretto ◽  
Gloria Burlacchini ◽  
Carla Pruzzo ◽  
Pietro Canepari
Keyword(s):  
Enterococcus Faecalis ◽  
Microbiological Quality ◽  
Lipoteichoic Acid ◽  
Survival Strategies ◽  
Natural Environments ◽  
Human Pathogens ◽  
Vbnc State ◽  
Adhesive Properties ◽  
Main Component

ABSTRACT Several human pathogens and fecal-pollution indicators may persist as viable organisms in natural environments, owing to their ability to activate different types of survival strategies. These strategies include adhesion on both abiotic and biotic surfaces and the entrance to the so-called viable but nonculturable (VBNC) state. In an 18-month survey for the detection of enterococci in both lake water and seawater, C. Signoretto et al. (Appl. Environ. Microbiol. 70:6892-6896, 2004) have shown that Enterococcus faecalis was detected mostly bound to plankton and in the VBNC state. In the present study, we show that in vitro adhesion of E. faecalis to copepods accelerated the entry of cells into the VBNC state relative to that of planktonic bacteria. VBNC E. faecalis cells maintained their adhesive properties to copepods and chitin (the main component of the copepod carapace), though to a reduced extent in comparison with growing cells. Sugar competition experiments showed interference with adhesion to both copepods and chitin by GlcNAc and only to copepods by d-mannose. Four enterococcal cell wall proteins present in both growing and VBNC cells and lipoteichoic acid were shown to be capable of binding chitin. The results indicate that copepods may represent an additional environmental reservoir of enterococci, thus suggesting the advisability of redesigning the protocols currently used for microbial detection during the evaluation of the microbiological quality of environmental samples.

scholarly journals Attenuated Vancomycin Bactericidal Activity against Staphylococcus aureus hemB Mutants Expressing the Small-Colony-Variant Phenotype

2008 ◽  
Vol 52 (4) ◽  
pp. 1533-1537 ◽  
Author(s):  
Brian T. Tsuji ◽  
Christof von Eiff ◽  
Pamela A. Kelchlin ◽  
Alan Forrest ◽  
Patrick F. Smith
Keyword(s):  
Staphylococcus Aureus ◽  
Bactericidal Activity ◽  
Pharmacodynamic Model ◽  
Small Colony Variant ◽  
Variant Phenotype ◽  
Small Colony ◽  
Bactericidal Activities

ABSTRACT The in vitro bactericidal activities of vancomycin against Staphylococcus aureus hemB mutants displaying the small-colony-variant phenotype and their parental strains were evaluated. Vancomycin killing activities against hemB mutants were markedly attenuated, demonstrating approximately 50% less effect, a result which was well described by a Hill-type pharmacodynamic model.

scholarly journals Staphylococcus aureus Fatty Acid Auxotrophs Do Not Proliferate in Mice

2013 ◽  
Vol 57 (11) ◽  
pp. 5729-5732 ◽  
Author(s):  
Joshua B. Parsons ◽  
Matthew W. Frank ◽  
Jason W. Rosch ◽  
Charles O. Rock
Keyword(s):  
Fatty Acids ◽  
Staphylococcus Aureus ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Normal Growth ◽  
Acid Synthesis ◽  
Acetyl Coa Carboxylase ◽  
Acetyl Coa ◽  
Content Type

ABSTRACTInactivation of acetyl-coenzyme A (acetyl-CoA) carboxylase confers resistance to fatty acid synthesis inhibitors inStaphylococcus aureuson media supplemented with fatty acids. The addition ofanteiso-fatty acids (1 mM) plus lipoic acid supports normal growth of ΔaccDstrains, but supplementation with mammalian fatty acids was less efficient. Mice infected with strain RN6930 developed bacteremia, but bacteria were not detected in mice infected with its ΔaccDderivative.S. aureusbacteria lacking acetyl-CoA carboxylase can be propagatedin vitrobut were unable to proliferate in mice, suggesting that the acquisition of inactivating mutations in this enzyme is not a mechanism for the evasion of fatty acid synthesis inhibitors.

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