Antibacterial, anti fungal and E. coli DNA cleavage of Euphorbia prostrata and Pelargonium graveolens extract and their combination with novel nanoparticles

As there are a lot of antibacterial and anti-fungal resistant pathogens, researchers attempt to substitute antimicrobial drugs with various medical plants and novel nanoparticles. The present study was conducted to characterize antimicrobial activities of Euphorbia prostrata and Pelargonium graveolens extract alone and in combination with Mn-Ni@Fe3O4-NPs & Mn: Fe (OH)3-NPs on the DNA cleavage of E. coli and also Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Aspergillus oryzae, and Candida albicans. The effects of antimicrobial activities on above scenarios were evaluated using disc diffusion, MIC, MBC, and E. coli DNA electrophoresis methods. The results showed that the effects of antibacterial assay values of Euphorbia prostrata & Mn: Fe(OH)3 was 21.00 mm for E. coli and while it was 19.5 mm for Euphorbia prostrata & Mn-Ni@Fe3O4 against Pseudomonas aeruginosa at a concentration of 100mg/mL. The highest level of DNA cleavage was seen in mixed of Euphorbia prostrata & Mn: Fe(OH)3 nanoparticles. In conclusion, the combination of Euphorbia prostrata and Pelargonium graveolens extracts with nanostructures showed synergic effects on eliminating the bacteria via DNA destruction and others mechanisms. Moreover, the synergistic effect of nanoparticles with plant extracts seems to bring about new choices for the treatment of infectious diseases

Extracellular phospholipase production of oral Candida albicans isolates from smokers, diabetics, asthmatics, denture wearers and healthy individuals following brief exposure to polyene, echinocandin and azole antimycotics

Abstract Objective Candida albicans is the primary causative agent of oral candidosis, and one of its key virulent attributes is considered to be its ability to produce extracellular phospholipases that facilitate cellular invasion. Oral candidosis can be treated with polyenes, and azoles, and the more recently introduced echinocandins. However, once administered, the intraoral concentration of these drugs tend to be sub-therapeutic and rather transient due to factors such as the diluent effect of saliva and cleansing effect of the oral musculature. Hence, intra-orally, the pathogenic yeasts may undergo a brief exposure to antifungal drugs. We, therefore, evaluated the phospholipase production of oral C. albicans isolates following brief exposure to sub-therapeutic concentrations of the foregoing antifungals. Materials and methods Fifty C. albicans oral isolates obtained from smokers, diabetics, asthmatics using steroid inhalers, partial denture wearers and healthy individuals were exposed to sub-therapeutic concentrations of nystatin, amphotericin B, caspofungin, ketoconazole and fluconazole for one hour. Thereafter the drugs were removed and the phospholipase production was determined by a plate assay using an egg yolk-agar medium. Results The phospholipase production of these isolates was significantly suppressed with a percentage reduction of 10.65, 12.14, 11.45 and 6.40% following exposure to nystatin, amphotericin B, caspofungin and ketoconazole, respectively. This suppression was not significant following exposure to fluconazole. Conclusions Despite the sub-therapeutic, intra oral, bioavailability of polyenes, echinocandins and ketoconazole, they are likely to produce a persistent antifungal effect by suppressing phospholipase production, which is a key virulent attribute of this common pathogenic yeast.

Impact of brief exposure to antifungal agents on the post-antifungal effect and hemolysin activity of oral Candida albicans

AbstractPost-antifungal effect (PAFE) of Candida and its production of hemolysin are determinants of candidal pathogenicity. Candida albicans is the foremost aetiological agent of oral candidosis, which can be treated with polyene, azole, and echinocandin antifungals. However, once administered, the intraoral concentrations of these drugs tend to be subtherapeutic and transient due to the diluent effect of saliva and cleansing effect of the oral musculature. Hence, intra-orally, Candidamay undergo a brief exposure to antifungal drugs.Objective Therefore, the PAFE and hemolysin production of oral C. albicans isolates following brief exposure to sublethal concentrations of the foregoing antifungals were evaluated.Material and Methods A total of 50 C. albicans oral isolates obtained from smokers, diabetics, asthmatics using steroid inhalers, partial denture wearers and healthy individuals were exposed to sublethal concentrations of nystatin, amphotericin B, caspofungin, ketoconazole and fluconazole for 60 min. Thereafter, the drugs were removed and the PAFE and hemolysin production were determined by previously described turbidometric and plate assays, respectively.Results Nystatin, amphotericin B, caspofungin and ketoconazole induced mean PAFE (hours) of 2.2, 2.18, 2.2 and 0.62, respectively. Fluconazole failed to produce a PAFE. Hemolysin production of these isolates was suppressed with a percentage reduction of 12.27, 13.47, 13.33, 8.53 and 4.93 following exposure to nystatin, amphotericin B, caspofungin, ketoconazole and fluconazole, respectively.Conclusions Brief exposure to sublethal concentrations of antifungal drugs appears to exert an antifungal effect by interfering with the growth as well as hemolysin production of C. albicans.

Evaluation of Swallowing in Infants with Congenital Heart Defect

Introduction Surgical repair of congenital heart disease in the first years of life compromises the coordination of the suction, breathing, and swallowing functions. Objective To describe the alterations in swallowing found in infants with congenital heart defect during their hospitalization. Methods Prospective, cross-sectional study in a reference hospital for heart disease. The sample consisted of 19 postsurgical patients who underwent an evaluation of swallowing. The infants included were younger than 7 months and had a diagnosis of congenital heart defect and suspected swallowing difficulties. Results Of the 19 infants with congenital heart defect, the median age was 3.2 months. A significant association was found between suction rhythm and dysphagia (p = 0.036) and between oral-motor oral feeding readiness and dysphagia (p = 0.014). Conclusions The data suggest that dysphagia often occurs after surgery in infants with congenital heart defect. Infants with congenital heart defect had very similar behavior to preterm infants in terms of oral feeding readiness. .

Comparison of the hemolytic activity between C. albicans and non-albicans Candida species

The ability to produce enzymes, such as hemolysins, is an important virulence factor for the genus Candida.The objective of this study was to compare the hemolytic activity between C. albicansand non-albicans Candida species. Fifty strains of Candida species, isolated from the oral cavity of patients infected with HIV were studied. The isolates included the following species: C. albicans, C. dubliniensis, C. glabrata, C. tropicalis, C. krusei, C. parapsilosis, C. dubliniensis, C. norvegensis, C. lusitaniae, and C. guilliermondii. Hemolysin production was evaluated on Sabouraud dextrose agar containing chloramphenicol, blood, and glucose. A loop-full of pure Candidaculture was spot-inoculated onto plates and incubated at 37ºC for 24 h in a 5% CO2 atmosphere. Hemolytic activity was defined as the formation of a translucent halo around the colonies. All C. albicansstrains that were studied produced hemolysins. Among the non-albicans Candidaspecies, 86% exhibited hemolytic activity. Only C. guilliermondiiand some C. parapsilosis isolates were negative for this enzyme. In conclusion, most non-albicans Candidaspecies had a similar ability to produce hemolysins when compared to C. albicans.

Biofilm Formation and Antifungal Susceptibility of Candida Isolates from Various Clinical Specimens.

Background: Candida species are now recognized as major causative agents of hospitalacquired infection. Aims: To evaluate the species distribution, biofilm formation,and antifungal susceptibility (amphotericin B, ketoconazole, and fluconazole) of Candida isolates. Place and Duration of Study: This is a Six-months Cross sectional study conducted in Alansar hospital, Al-Madinah, Saudi Arabia. Methodology: One hundred and three isolates of Candida spp. were cultured on Sabouraud dextrose agar (SDA). Candida spp. were identified by four standard methods, CHROMagar candida, cornmeal agar, germ tube test and API 20C. Detection of Biofilm formation was done by microtitre plate and antifungal susceptibility testing was done by disc diffusion. Results: C. albicans was the most common species 61%, followed by C. tropicalis 25%, C. lusitanaie 5%, C. parapsilosis 4%, C. glabrata 4% and C. famata 1%. Biofilm formation was found to occur most frequently among non-albicans spp.(70%) than C. albicans (46%). All isolates were sensitive to amphotericin B and ketoconazole. Resistance to fluconazole was found in 22.5% of non-albicans spp. and 5% of C. albicans isolates. Conclusion: The present study proved that C. albicans is still the major isolate from urinary, vaginal and respiratory samples but non-albicans spp. predominate in the blood samples and from plastic devices. The non-albicans spp. were more biofilm - producers compared to C. albicans and C. tropicalis showed the highest score of biofilm intensity (grade 4+). The species isolated are less susceptible to fluconazole.

Anaerobic enhancement of protease secretion by periodontal Candida albicans strains / Aumento anaeróbio da secreção de protease pelas cepas de Candida albicans periodontal

Among other non-bacterial organisms, yeasts have been isolated from subgingival sites with relative frequency. Candida albicans is the species most commonly isolated although its role in periodontal disease has not been established. Objective: This study evaluated the secretion patterns of aspartyl-protease (Sap) by periodontal and nonperiodontal Candida albicans strains in normoxic and anoxic conditions. Material and methods: Periodontal strains (n=10; periodontal pockets ≥3.00 mm) and nonperiodontal Candida albicans strains (n=10) were grown under normoxic and anoxic conditions in protease-inducible broth. Sap activities were quantified in supernatants using azocasein as substrate. Whole-protein contents in supernatants were determined by Bradford’s method. Specific protease activities (Sap activity.protein-1) were assessed and compared. Results: While nonperiodontal strains secrete similar amounts of Sap under both atmospheric conditions, periodontal strains secrete reduced amounts in the presence of molecular oxygen. Conclusion: Despite the limited number of assayed isolates, the possibilities of adaptation or selection of candidal strains to periodontal microenvironment may be considered...

Entre organismos não bacterianos, as leveduras têm sido isoladas de sítios subgengivais com relativa frequência. Candida albicans é a espécie mais comumente isolada, embora seu papel na doença periodontal não esteja estabelecido. Objetivo: Este estudo avaliou os padrões de secreção de aspartil-protease (Sap) por cepas periodontais e não periodontais de Candida albicans em situações de normóxia e anóxia. Material e métodos: Cepas periodontais (n=10; bolsas periodontais ≥3,00 milímetros) e cepas de não periodontais (n=10) Candida albicans foram cultivadas sob condições normóxicas e anóxicas em caldo de protease-induzida. A atividade Sap foi quantificada em sobrenadantes utilizando azocaseína como substrato. O conteúdo de proteínas totais nos sobrenadantes foi determinado pelo método de Bradford. Atividades de protease específica (atividade de proteína Sap-1) foram avaliadas e comparadas. Resultados: Apesar das cepas não periodontais secre¬tarem quantidades semelhantes de Sap em ambas as condições atmosféricas, as cepas periodontais secretam quantidades reduzidas na presença de oxigênio molecular. Conclusão: Apesar do número limitado de amostras analisadas, as possibilidades de adaptação ou seleção de cepas de Candida no microambiente periodontal pode ser considerada...

Oxidative stress response to menadione and cumene hydroperoxide in the opportunistic fungal pathogen Candida glabrata

Candida glabrata is an opportunistic fungal pathogen that can cause severe invasive infections and can evade phagocytic cell clearance. We are interested in understanding the virulence of this fungal pathogen, in particular its oxidative stress response. Here we investigated C. glabrata, Saccharomyces cerevisiae and Candida albicans responses to two different oxidants: menadione and cumene hydroperoxide (CHP). In log-phase, in the presence of menadione, C. glabrata requires Cta1p (catalase), while in a stationary phase (SP), Cta1p is dispensable. In addition, C. glabrata is less resistant to menadione than C. albicans in SP. The S. cerevisiae laboratory reference strain is less resistant to menadione than C. glabrata and C. albicans; however S. cerevisiaeclinical isolates (CIs) are more resistant than the lab reference strain. Furthermore, S. cerevisiae CIs showed an increased catalase activity. Interestingly, in SP C. glabrata and S. cerevisiae are more resistant to CHP than C. albicans and Cta1p plays no apparent role in detoxifying this oxidant.

Phenotypic switching and its influence on expression of virulence factors by Candida albicans causing candidiasis in human immunodeficiency virus-infected patients.

PURPOSE: The purpose of the present study was to determine the degree of expression of virulence factors such as adherence, cell surface hydrophobicity (CSH) and production of proteinase by different morphological forms of Candida albicans causing oral candidiasis in human immunodeficiency virus (HIV)-infected individuals. METHODS: C. albicans 3153A and two strains isolated from oral thrush in HIV infected individuals were induced to undergo phenotypic switching by exposure to UV light and the degree of expression of virulence factors by the different morphological forms was studied. RESULTS: Three different morphological forms of C. albicans were obtained namely, star (S), wrinkled (W) and ring (R) types from the original smooth (O) variety. It was found that proteinase production was greatest with the W type followed by the R type and O type. The S type produced the least proteinase. Expression of cell surface hydrophobicity and adherence was greatest in the O type followed by the R and then the W type and finally the S type. CONCLUSIONS: The differential expression of virulence factors occurs with different phenotypic forms of C. albicans and this may provide a particular morphological type with a distinct advantage over other types in causing candidiasis.

Efeito do dietilditiocarbamato de sódio (DETC) na susceptibilidade da cândida albicans à anfotericina B: em busca do sinergismo / Effect of diethyldithiocarbamate sodium (DETC) in the susceptibility of candida albicans to amphotericin B: in search of synergism

Candida albicans, fungo cosmopolita, é considerado um comensal comum da microbiota de pessoas saudáveis. No entanto, com o avanço da AIDS e outras condições que comprometem o sistema imunológico, como o tratamento de neoplasias dentre outros, fizeram com que as infecções fúngicas aumentassem 400 por cento nas últimas duas décadas (Beck-Sangue et al., 1993; Pfaller, 1994; Jarvis et al., 1995). A superóxido dismutase (SOD), fator de virulência em C. albicans, é requerida na detoxificação do superóxido. Sendo o dietilditiocarbamato de sódio (DETC) um potente inibidor da SOD, avaliamos no presente estudo o seu efeito fungicida na proliferação in vitro da Candida albicans, sozinho e em combinação com a anfotericina B. O DETC demonstrou um efeito dose-dependente e inibição significativa da proliferação com apenas 6hs de cultivo. A sua combinação com a anfotericina apresentou um efeito sinérgico com FIC = 0,8. Com o objetivo de avaliar as alterações ultraestiuturais induzidas pelo DETC, as leveduras foram tratadas ou não por 24 horas e então processadas para microscopia eletrônica de transmissão. A ultraestrutura de leveduras tratadas com 100l-tM ou 150l-tM de DETC apresentaram extração quase completa do citoplasma e componentes intracelulares. Além disso, foram observados múltiplos corpos vesiculares, contendo matéria de natureza diversa e figuras de mielina. Nossos dados sugerem indução de processo autofágico porém, novos experimentos com abordagem citoquímica serão realizados para confirmação dos resultados.

Evaluation of phytochemical and antimicrobial properties of leaf extract of Tapinanthus sessilifolius (P. Beauv) van Tiegh.

Leaf extracts of T. sessilifolius growing on five different host plants (Psidium guajava, Citrus lemon, Vernonia amygdalina, Persea americana and Jatropa curcas) were evaluated for antimicrobial activity of the plant. Powdered leaves of T. sessilifolius collected from each host plant was divided into two portions. One portion was used for aqueous infusion and the other portion was successively extracted with hexane, ethylacetate and methanol. Infusion of aqueous extract of powdered leaves did not show antimicrobial effect even at the concentration of 1000 and 2000 microg/ml on test microorganisms (Staph. aureus, E. coli, Bacillus subtilis, Pseudomonas aeruginosa and Candida albicans). However in broth culture, methanolic and hexane extract had MIC range of 62.5-500 microg/ml and ethylacetate extract had 250-500 microg/ml. Phytochemical screening of leaf samples of T. sessilifolius collected from different host plants showed positive test for hydrolysable tannins, saponins, flavonoids, terpenes, cardiac glycoside, reducing sugars and proteins. LD50 concentration was found to be > 1.500 mg/kg for samples from P. guajava; 489.89 mg/kg for J. curcas and C. lemon; and 692 mg/kg for V. amydalina in mice.

Resistence of Candida species to antifungal agents: molecular mechanisms and clinical consequences

Candida albicans and related species pathogenic for man become resistent to antifungal agents, in particular triazole compounds, by expression of efflux pumps that reduce drug accumulation, alteration of the structure or concentration of antifungal target proteins, and alteration of membrane sterol composition. The clinical consequences of antifungal resistence can be seen in treatment failures in patients and in changes in the prevalence of Candida species causing disease. These effects were seen unequivocally in HIV-infected patients with oropharyngel candida infections, but their incidence has decreased dramatically with the introduction of highly active antiretroviral therapy. The evidence for similar emergence of antifungal-resistant yeast strains and species in other types of candida infections is confounded by non-standardised susceptibillity testing methods and definitions of a resistent fungal isolate. Recent large-scale surveys of yeasts isolated from blood cultures, based on standardised methodology and resistence definitions, do not support the view that antifungal resistance in pathogenic yeasts contitutes a significant or growing therapeutic problem

Effects of interleukin-10 on chemokine KC gene expression by mouse peritoneal macrophages in response to Candida albicans

Chemokine KC has been considered to be a murine homologue of human GRO/MGSA and was identified as chemoattractant for monocytes and neutrophils. This study examined the expression of KC mRNA in thioglycollate-elicited mouse peritoneal macrophages that were stimulated in vitro with Candida albicans (CA). Also examined were the inhibitory effects of IL-10 on the CA-induced expression of KC gene by Northern blot analysis. CA was found to induce chemokine gene expression in a gene-specific manner, CXC chemokine IP-10 mRNA expression was not detected in CA-stimulated macrophages. Maximum KC mRNA expression was observed approximately 2 hr after adding CA. The inhibitory action of IL-10 to CA-induced KC mRNA expression on mouse peritoneal macrophages was independent on concentration and stimulation time of IL-10 and was observed approximately one hour after adding IL-10 and CA simultaneously. IL-10 produced a decrease in the stability of KC mRNA, and CA-stimulated macrophages with cycloheximide blocked the suppressive effect of IL-10. These results suggest that CA also induces chemokine KC from macrophages, and IL-10 acts to destabilize CA-induced KC mRNA and de novo synthesis of an intermediate protein is a part of the IL-10 suppressive mechanism.

Toxinas killer e produção de enzimas por Candida albicans isoladas da mucosa bucal de pacientes com câncer / Killer toxin and enzyme production by Candida albicans isolated from buccal mucosa in patients with cancer

Opportunistic infections of the oral cavity are primarily caused by Candida and frequently occur in patients with cancer who are undergoing chemotherapy and antibiotic treatment. Of the specimens received from the oral mucosa of 44 patients with cancer, 25 (56.8%) yielded Candida on culture in Sabouraud agar. Twenty four of these isolates were identified as C. albicans (96%) and 1 as C. krusei (4%). The phenotypic characteristics of these isolates showed that all of them were strongly proteolytic, had a high ability to produce phospholipase, and presented the byotypes characterized as 811 (95.8%) and 511 (4.2%) in terms of susceptibility to killer toxins.

Infecções oportunistas da cavidade bucal são primariamente causadas por fungos do gênero Candida e freqüentemente ocorrem em pacientes com câncer que estão sobtratamento quimioterápico e antibacteriano. De 44 amostras coletadas da mucosa oral de pacientes com câncer, observou-se o isolamento de 25 leveduras do gênero Candida em cultivo realizado em ágar Sabouraud-dextrose. Foram identificados Candida albicans em 24 (96%) isolados e C. krusei em 1 (4%). As características fenotípicas das amostras de Candida albicans mostraram que todos os isolados foram fortemente proteolíticos, capazes de produzir fosfolipases e possuíam os biotipos caracterizados como 811(95,8%) e 511 (4,2%) em relação a susceptibilidade às toxinas killer.

Aglutinaçäo microscópica para identificaçäo de Candida albicans sorogrupos "A" e "B" / Microscopic agglutination for the identification of Candida albicans serogroups \"A\" and \"B\"

Neste trabalho está sendo proposta a leitura microscópica para visualizaçäo da reaçäo de aglutinaçäo em substituiçäo à leitura realizada a olho nu na identificaçäo de Candida albicans sorogrupos "A" e "B". A leitura microscópica pode dirimir qualquer dúvida encontrada na leitura a olho nu.

Sustancias complejantes que facilitan la producción de clamidosporos para la identificación de Cándida albicans / Complex substances that facilited the production the clamidospores for the identification of Candida albicans

La influencia de polisacáridos y de ciertas condiciones físico-químicas es conocida en la formación de seudomicelios y clamidosporos, como las producidas por la presencia de sustancias tensioactivas. Se procuró establecer, hasta qué punto sustancias complejantes como el EDTA (sal sódica del ácido etilendiaminotetracético), el citrato de sodio y el oxalato de sodio, podrían igualmente influir en el dimorfismo del hongo. Se utilizaron cepas de Candida albicans aisladas de procesos patológicos e identificadas por zimograma y auxanograma. Fueron sembradas en medios de agua harina de maíz y agua papa-zanahoria, a los que se les había incorporado los complejantes por separado. Como controles se emplearon los mismos medios sin aditamentos con el agregado de tween 80. Las concentraciones se fueron regulando por estudios previos hasta poder obtener las más útiles para nuestros fines. Se comprobaron buenos resultados con la incorporación de los distintos complejantes para la formación de filamentos y clamidosporos, pero fueron inferiores a los resultados obtenidos con el uso del tensioactivo (tween 80)