Synergism between plant extract and antimicrobial drugs used on Staphylococcus aureus diseases

Searches for substances with antimicrobial activity are frequent, and medicinal plants have been considered interesting by some researchers since they are frequently used in popular medicine as remedies for many infectious diseases. The aim of this study was to verify the synergism between 13 antimicrobial drugs and 8 plant extracts - guaco (Mikania glomerata), guava (Psidium guajava), clove (Syzygium aromaticum), garlic (Allium sativum), lemongrass (Cymbopogon citratus), ginger (Zingiber officinale), carqueja (Baccharis trimera), and mint (Mentha piperita) - against Staphylococcus aureus strains, and for this purpose, the disk method was the antimicrobial susceptibility test performed. Petri dishes were prepared with or without dilution of plant extracts at sub-inhibitory concentrations in Mueller-Hinton Agar (MHA), and the inhibitory zones were recorded in millimeters. In vitro anti-Staphylococcus aureus activities of the extracts were confirmed, and synergism was verified for all the extracts; clove, guava, and lemongrass presented the highest synergism rate with antimicrobial drugs, while ginger and garlic showed limited synergistic capacity.

Atividade antibacteriana de óleos essenciais de plantas frente a linhagens de Staphylococcus aureus e Escherichia coli isoladas de casos clínicos humanos

A ação antibacteriana in vitro de óleos essenciais de seis plantas foi verificada por meio da Concentração Inibitória Mínima (CIM=%v/v) pela diluição dos óleos em meio de cultura Mueller Hinton Agar, frente a linhagens de Staphylococcus aureus (n=16) e Escherichia coli (n=16) isoladas de casos clínicos humanos, além de 1 amostra padrão ATCC para cada espécie (Sa ATCC 25923 e Ec ATCC 25922), e determinação de curvas de sobrevivência em concentrações equivalentes a CIM90% dos respectivos óleos. O óleo essencial de canela foi o mais eficiente, com valores de CIM90% de 0,047 e 0,09 para S. aureus e E. coli respectivamente, enquanto gengibre (0,09), cravo da índia (0,095) e capim cidreira (0,1) apresentaram eficiências semelhantes para S. aureus. Frente a E. coli, os óleos de gengibre (0,52) e capim cidreira (0,55) foram equivalentes quanto à eficiência. de acordo com as curvas de sobrevivência, foi possível verificar também que os valores de CIM90% obtidos podem ser tanto bactericidas ou bacteriostáticas de acordo com a bactéria testada. em conclusão, verificou-se que os óleos essenciais testados foram efetivos no controle do desenvolvimento bacteriano, sendo o potencial antimicrobiano diferente em função da espécie bacteriana testada, sendo que a bactéria Gram positiva (S. aureus) mostrou-se mais susceptível aos óleos testados que a Gram negativa (E. coli).

Importância do Staphylococcus aureus nas mastites subclínicas: pesquisa de enterotoxinas e toxina do choque tóxico, e a relação com a contagem de células somáticas

O Staphylococcus aureus é um dos principais agentes das mastites consideradas contagiosas, apresentando elevada incidência na maioria dos rebanhos leiteiros em vários países. Além de perdas econômicas é importante salientar o aspecto de saúde pública para cepas produtoras de enterotoxinas e da toxina do choque tóxico. A enterotoxina A, relacionada com maior ênfase nos casos de toxinfecções alimentares, pode ser veiculada pelo leite cru, pasteurizado e subprodutos lácteos. A síndrome do choque tóxico é determinada mais freqüentemente pela toxina do choque tóxico, porém as enterotoxinas do tipo B e C também podem ser implicadas. O objetivo deste estudo foi verificar a ocorrência de S.aureus produtores de enteroxinas e da toxina do choque tóxico em amostras de leite de animais com mastite subclínica, e correlacionar estes resultados com a contagem de células somáticas; utilizando a técnica de celofane over agar para detecção da TNAase, kit comercial para identificação das enterotxinas e contagem eletrônica de células somáticas. Avaliod]MORENO, B.[u-se 209 amostras de leite oriundas de vacas com mastite subclínica por S.aureus, e dentre estas, 209 (98,86%) produziram TNAse, nove amostras (4,39%) foram produtoras de enterotoxinas, sendo que uma (0,49%) dentre elas foi produtora de EED, três (1,46%) de EEC, e três (1,46%) de EEB. em uma amostra (0,49%), detectou-se concomitantemente EEA e EEB e em outra EEB e EEC. A toxina do choque tóxico não foi encontrada nas cepas avaliadas neste estudo, assim como não houve aumento estatisticamente significativo, na contagem de células somáticas, das amostras de cepas produtoras de enteroxinas.

Detection of enterotoxin genes of Staphylococcus sp isolated from nasal cavities and hands of food handlers

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Oxacillin Resistance and Antimicrobial Susceptibility Profile of Staphylococcus saprophyticus and Other Staphylococci Isolated from Patients with Urinary Tract Infection

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Anti-coagulase-negative Staphylococcus activity of ethanolic extracts of propolis from two Brazilian regions and synergism with antimicrobial drugs by the E-test method

Propolis is a natural resinous substance collected by bees from vegetal sources and its therapeutic properties have been investigated. In this work, we evaluated the inhibitory activity of ethanolic extracts of propolis (EEP) from the Southeast and South of Brazil on coagulase-negative Staphylococcus (CNS) growth as well as the EEP in vitro synergism with antimicrobial drugs by using the diffusion method (E-test). The EEP chemical characteristics (dry weight, pH, flavonoid and phenolic compounds) were determined. Seven drugs were tested, and synergism was observed between three drugs and Southeast EEP, six drugs and South EEP, and one drug and ethanol control. Ethanolic extracts of propolis from the South of Brazil presented the greatest flavonoid content and synergism rate, while EEP from the Southeast presented the greatest anti-CNS activity and phenolic compound content. Results showed the correlation among anti-CNS activity, synergism rate and chemical characteristics of propolis.

Determination of toxigenic capacity by reverse transcription polymerase chain reaction in coagulase-negative staphylococci and Staphylococcus aureus isolated from newborns in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Identification and antimicrobial susceptibility of Staphylococcus from home-treated peritoneal dialysis patients

Staphylococcus aureus is the main agent of infections during peritoneal dialysis (PD). The presence of S. aureus in the nasal cavity has been extensively studied and suggested as a risk factor of dialysis-related infections, whereas coagulase-negative Staphylococcus (CNS) species are frequently considered part of the normal human microbiota. The aim of this study was to identify Staphylococcus in the nasal cavity, pericatheter skin and peritoneal effluent from PD patients, as well as to evaluate the antimicrobial activity evolution in vitro. Thirty-two chronic PD patients were observed during 12 months and had nasal and pericatheter skin samples collected for culture. When peritonitis was detected, samples were also collected from the peritoneal effluent for culture. The activity of several antimicrobial drugs (penicillin G, oxacillin, cephalothin, ofloxacin, netilmicin and vancomycin) against different Staphylococcus species was measured by using the agar drug diffusion assay (Kirby-Bauer method). Staphylococcus was separated into S. aureus, S. epidermidis and other CNS species in order to determine the in vitro resistance level. S. epidermidis resistance to oxacillin progressively increased during the study period (p < 0.05). Resistance to ofloxacin was inexpressive, whereas resistance to netilmicin and vancomycin was not detected. of the oxacillin-resistant species (n = 74), 83% were S. epidermidis, 13% other CNS and 4% S. aureus (p < 0.05). Regarding multidrug resistant strains (n = 45), 82% were S. epidermidis, 13% other CNS, and 5% S. aureus (p < 0.05). This study shows the relevance of resistance to oxacillin and CNS multi-drug resistance, particularly concerning S. epidermidis, in PD patients.

Molecular detection of enterotoxins E, G, H and I in Staphylococcus aureus and coagulase-negative staphylococci isolated from clinical samples of newborns in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

PCR detection of staphylococcal enterotoxin genes in Staphylococcus aureus strains isolated from raw and pasteurized milk

Milk is considered a nutritious food because it contains several important nutrients including proteins and vitamins. Conversely, it can be a vehicle for several pathogenic bacteria such as Staphylococcus aureus. This study aimed to analyze the frequency of genes encoding the staphylococcal enterotoxins (SEs) SEA, SEB, SEC, SED, SEE, SEG, SEH, SEI and SEJ in S. aureus strains isolated from raw or pasteurized bovine milk. S. aureus was found in 38 (70.4%) out of 54 raw milk samples at concentrations of up to 8.9 X 10(5) CFU/ml. This microorganism was present in eight samples of pasteurized milk before the expiration date and in 11 samples analyzed on the expiration date. of the 57 strains studied, 68.4% were positive for one or more genes encoding the enterotoxins, and 12 different genotypes were identified. The gene coding for enterotoxin A, sea, was the most frequent ( 16 strains, 41%), followed by sec (8 strains, 20.5%), sed (5 strains, 12.8%). seb (3 strains. 7.7%) and see (2 strains, 5.1%). Among the genes encoding the other enterotoxins, seg was the most frequently observed (11 strains. 28.2%), followed by sei (10 strains) and seh and sej (3 strains each). With the recent identification of new SEs, the perceived frequency of enterotoxigenic strains has increased. suggesting that the pathogenic potential of staphylococci may be higher than previously thoughts however, further studies are required to assess the expression of these new SEs by S. aureus. and their impact in foodborne disease. The quality of Brazilian milk is still low. and efforts from the government and the entire productive chain are required to attain consumer safety. (C) 2008 Elsevier B.V. All rights reserved.

Immunization protected well nourished mice but not undernourished ones from lung injury in Methicillin-resistant Staphylococcus aureus (MRSA) infection

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Phenotype characterization of Staphylococcus species strains isolated from buffalo (Bubalus bubalis) milk

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sinergismo entre óleos essenciais e drogas antimicrobianas sobre linhagens de Staphylococcus aureus e Escherichia coli isoladas de casos clínicos humanos

Estudos com plantas e utilização em terapias combinatórias têm sido estimulados. Verificou-se as possíveis interações entre óleos essenciais de plantas [canela (Cinnamomum zeylanicum Blume Lauraceae), capim-cidreira (Cymbopogon citratus (DC.) Stapf, Poaceae), hortelã-pimenta (Mentha piperita L. Lamiaceae), gengibre (Zingiber officinale Roscoe Zingiberaceae), cravo-da-índia (Caryophillus aromaticus L. Myrtaceae) e alecrim (Rosmarinus officinalis L. Lamiaceae)] combinados a oito drogas antimicrobianas frente a doze linhagens de Staphylococcus aureus e doze de Escherichia coli isoladas de humanos. Após determinação da Concentração Inibitória Mínima (CIM) para os óleos pelo método da diluição foram realizados ensaios para verificação de sinergismo entre os óleos essenciais e os antimicrobianos pela metodologia de Kirby & Bauer. S. aureus foi mais suscetível às interações óleos e drogas, tendo o óleo de capim cidreira apresentado sinergismo com as oito drogas testadas, seguido pelo óleo de hortelã com sete drogas. Nos ensaios com E. coli, houve sinergismo apenas para os óleos de alecrim (três drogas) e capim-cidreira (duas drogas). Não ocorreram casos de antagonismo e os resultados de sinergismo foram influenciados pelos microrganismos estudados.

A thin layer electrochemical cell for disinfection of water contaminated with Staphylococcus aureus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Tertiary structural changes of the alpha-hemolysin from Staphylococcus aureus on association with liposome membranes

The interaction of alpha-hemolysin (also called alpha-toxin) from Staphylococcus aureus with mixed egg-yolk phosphatidylcholine/cholesterol liposomes has been investigated using the intrinsic tryptophan fluorescence emission (ITFE) signal. The ITFE intensity of alpha-hemolysin, which was obtained using a novel purification protocol, showed a triphasic increase on incubation with liposomes at low protein/lipid ratios. The first, rapid phase results in an increase in ITFE of 10%, which reflects rapid conformation changes in the alpha-hemolysin on association with the liposome membrane, the second phase of the ITFE increase is associated with a red shift from 334 to 339 nm in the maximum emission wavelength, suggesting the transition to a partially unfolded intermediate in the oligomerization process. The third phase of the ITFE intensity change demonstrates a temporal correlation with the appearance of SDS-stable oligomers. The results demonstrate the feasibility of identification of intermediate protein conformations in complex membrane-associated processes by manipulation of the liposomal membrane composition. (C) 1998 Academic Press.