Effect of organic substrate type in electricity production from microbial fuel cell (MFC) inoculated by Staphylococcus saprophyticus ICBB 9554

Microbial Fuel Cells (MFCs) are bioelectrochemical devices that can directly transform the chemical energy from organic matter into electrical energy using microbial metabolic activity, so microbes play an essential role. This study explores some organic substrate alternative cost-effective for Staphylococcus saprophyticus ICBB 9554 as an exoelectrogen for electricity production in MFCs. The organic substrates that were chosen were sugar, molasses, and palm sugar. The best performance in electricity production was in molasses which showed output voltage, electrical current, and power density of 789 mV, 0.48 mA, and 68 mW/m2, respectively. The COD removal, Coulombic efficiency, and bacterial density in molasses also the highest that was about 68.18 ± 0.00%, 45.80 ± 2.17%, and 1.09×108 cfu/ml, respectively. Molasses is a potentially cost-effective alternative organic substrate for MFCs inoculated by Staphylococcus saprophyticus ICBB 9554.

ANÁLISE DE CULTURA DE TELEFONES MÓVEIS DE PROFISSIONAIS DE ENFERMAGEM DE UMA UNIDADE HOSPITALAR PÚBLICA DE MINAS GERAIS

INTRODUÇÃO: Com a evolução da tecnologia e a disponibilização de telefonia móvel tornou-se cada dia mais comum estes aparelhos fazerem parte da rotina da população e também dos profissionais de saúde inclusive em seus ambientes de trabalho. Apesar dessa tecnologia trazer benefícios, pesquisadores têm associado a presença de patógenos de origem hospitalar em dispositivos de profissionais de saúde, o que torna susceptível a possíveis infecções e o carreamento desses agentes. Como o telefone móvel está em uso rotineiro, sendo visto inclusive em postos de enfermagem, surge à indagação e a necessidade de avaliarmos se há colonização destes aparelhos e quais agentes. OBJETIVO: Verificar se há colonização de telefones móveis dos profissionais de saúde (enfermagem) e se há alguma rotina de higienização dos celulares e se há adesão a higienização de mãos. METODOLOGIA: Foi aplicado um questionário aos profissionais de enfermagem de um hospital geral do interior de Minas Gerais, a amostra constou de 50 servidores, após foi coletado Swab umedecidos em caldo BHI (Brain Heart Infusion) dos telefones celulares deste profissionais. Após os swabs foram inoculados nos meios sólidos Ágar Sangue Colúmbia (Ágar MacConkey (meio seletivo e diferencial para detecção de bacilos entéricos Gram negativos, fermentadores ou não da lactose, em amostras diversas) e Ágar Chocolate (utilizado para o cultivo de microrganismos exigentes, embora cresçam neste meio quase todos os tipos de microrganismos. (meio nutricionalmente rico, não seletivo, geralmente utilizado para o isolamento e cultivo de microrganismos fastidiosos e não fastidiosos de uma variedade de materiais clínicos e não clínicos, possibilitando a verificação da atividade hemolítica das colônias). Foram incubadas em estufa a 35ºC ± 1ºC por 24 a 48 horas e após realizado a leitura do crescimento microbiológico. RESULTADOS: Após a coleta do material e análise das mesmas em laboratório, observado que houve crescimento em 33 amostras (66%), dentre os microorganismos identificados nas culturas temos: Staphylococcus aureus, Staphylococcus epidermides, Staphylococcus spp, Staphylococcus lugdunenis, Staphylococcus haemolyticus, Staphylococcus saprophyticus, Bastonetes gram negativos, Bastontes gram positivos e Candida sp. CONCLUSÃO: Conclui-se que há colonização dos aparelhos celulares, que podem proporcionar a propagação de agentes infecciosos e atuar diretamente na disseminação de microorganismos no ambiente hospitalar.

Titanium Dioxide Nanoparticles Induce Inhibitory Effects against Planktonic Cells and Biofilms of Human Oral Cavity Isolates of Rothia mucilaginosa, Georgenia sp. and Staphylococcus saprophyticus

Multi-drug resistant (MDR) bacterial cells embedded in biofilm matrices can lead to the development of chronic cariogenesis. Here, we isolated and identified three Gram-positive MDR oral cocci, (1) SJM-04, (2) SJM-38, and (3) SJM-65, and characterized them morphologically, biochemically, and by 16S rRNA gene-based phylogenetic analysis as Georgenia sp., Staphylococcus saprophyticus, and Rothia mucilaginosa, respectively. These three oral isolates exhibited antibiotic-resistance against nalidixic acid, tetracycline, cefuroxime, methicillin, and ceftazidime. Furthermore, these Gram positive MDR oral cocci showed significant (p < 0.05) variations in their biofilm forming ability under different physicochemical conditions, that is, at temperatures of 28, 30, and 42 °C, pH of 6.4, 7.4, and 8.4, and NaCl concentrations from 200 to 1000 µg/mL. Exposure of oral isolates to TiO2NPs (14.7 nm) significantly (p < 0.05) reduced planktonic cell viability and biofilm formation in a concentration-dependent manner, which was confirmed by observing biofilm architecture by scanning electron microscopy (SEM) and optical microscopy. Overall, these results have important implications for the use of tetragonal anatase phase TiO2NPs (size range 5–25 nm, crystalline size 13.7 nm, and spherical shape) as an oral antibiofilm agent against Gram positive cocci infections. We suggest that TiO2NPs pave the way for further applications in oral mouthwash formulations and antibiofilm dental coatings.

Photodynamic Inactivation Using Natural Bioactive Compound Prevents and Disrupts the Biofilm Produced by Staphylococcus saprophyticus

Staphylococcus saprophyticus, the food-borne bacteria present in dairy products, ready-to-eat food and environmental sources, has been reported with antibiotic resistance, raising concerns about food microbial safety. The antimicrobial resistance of S. saprophyticus requires the development of new strategies. Light- and photosensitizer-based antimicrobial photodynamic inactivation (PDI) is a promising approach to control microbial contamination, whereas there is limited information regarding the effectiveness of PDI on S. saprophyticus biofilm control. In this study, PDI mediated by natural bioactive compound (curcumin) associated with LED was evaluated for its potential to prevent and disrupt S. saprophyticus biofilms. Biofilms were treated with curcumin (50, 100, 200 µM) and LED fluence (4.32 J/cm2, 8.64 J/cm2, 17.28 J/cm2). Control groups included samples treated only with curcumin or light, and samples received neither curcumin nor light. The action was examined on biofilm mass, viability, cellular metabolic activity and cytoplasmic membrane integrity. PDI using curcumin associated with LED exhibited significant antibiofilm activities, inducing biofilm prevention and removal, metabolic inactivation, intracellular membrane damage and cell death. Likewise, scanning electronic microscopy observations demonstrated obvious structural injury and morphological alteration of S. saprophyticus biofilm after PDI application. In conclusion, curcumin is an effective photosensitizer for the photodynamic control of S. saprophyticus biofilm.

Bacterias aisladas de biosólidos de la PTAR San Fernando en Medellín-Colombia con capacidad para reducir cromo hexavalente

En las últimas décadas se ha trabajado activamente para reducir el impacto ambiental generado por las actividades antrópicas que constantemente liberan componentes tóxicos al ambiente generando inestabilidad y daños en la salud de las comunidades biológicas. Entre los diferentes contaminantes, los metales pesados revisten importancia en virtud de sus propiedades, que dificultan su degradación o transformación en otros compuestos menos tóxicos. El cromo es uno de los metales de mayor interés a nivel global por su uso en múltiples industrias. Los métodos convencionales que utilizan materiales cromados en sus procesos, no sólo arrojan cantidades considerables de residuos al ambiente, sino que dan poca cuenta de la fracción de Cr6+ presente en determinados ecosistemas. La biorremediación se ha propuesto como una alternativa económicamente viable y ambientalmente sostenible. El propósito del presente trabajo fue evaluar la capacidad de reducción de cromo por bacterias, aisladas de una matriz de biosólidos de la Planta de tratamiento de aguas residuales (PTAR) San Fernando en la ciudad de Medellín-Colombia. Muestras de biosólidos se cultivaron en Agar Nutritivo enriquecido con diferentes concentraciones de Cr6+. Las cepas que presentaron mayor tolerancia al cromo fueron aisladas para realizar ensayos de reducción por triplicado, monitoreando la concentración del metal en el tiempo. Se obtuvieron siete especies bacterianas diferentes dentro de las cuales se destacaron Staphylococcus saprophyticus, Ochrobactrum anthropi y Bacillus cereus por la capacidad de reducir Cr6+ a 96 h con eficiencias de 29.0%, 61.1% y 100%, respectivamente.

Determination of the Chemical Composition and Antimicrobial Activity of Lavatera thuringiaca L. Medicinal Herb Material Extracted under Subcritical Conditions by the Liquid Carbon Dioxide Method

This article presents the composition of the components of Lavatera thuringiaca L. (Malvaceae Juss. family), which has a certain antibacterial effect. The plant collection was carried out in the Shamalgan gorge of Mountain Range of the Trans-Ili Alatau in the territory of the Karasay district of the Almaty region, in the flowering phase. A CO2 extract of the aboveground part of the medicinal plant Lavatera thuringiaca L. was obtained under subcritical conditions and, for the first time, studied for its component composition and antimicrobial activity. Determination of the chemical composition of the extract was carried out by gas chromatography/mass spectrometry (GC/MS). To identify the obtained mass spectra, we used the Wiley 7th edition and the NIST’02 data library. To determine the antimicrobial and antifungal activity, standard test strains of microorganisms were used: Staphylococcus aureus ATCC 6538-P, Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 9027, Candida albicans ATCC 10231, Streptococcus pneumonia ATCC 660, Klebsiella pneumoniae ATCC 700603, Staphylococcus haemolyticus, and Staphylococcus saprophyticus. In the composition of thick CO2Lavatera thuringiaca L. extract, the content of 31 components was proven: spathulenol 6.97%, pulegone 5 08%, cis-β-farnesene 7.63%, verbenone 1.93%, α-bisabolol oxide B 9.65%, bisabolol oxide A 8.26%, α-bisabolol 1.36%, linolenic acid, ethyl ether 3.15%, phytol 2.49%, herniarin 5.61%, linolenic acid 9.38%, linoleic acid 6.95%, myristic acid 2.33%, and elaidic acid 2.57%. Antimicrobial activity studies have shown that the CO2 extract of Lavatera thuringiaca L. has a pronounced effect against clinically significant microorganisms: Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Streptococcus pneumonia, Klebsiella pneumoniae, Staphylococcus haemolyticus, and Staphylococcus saprophyticus. During testing, the method of serial dilutions proved that the extract of Lavatera thuringiaca L. has a bactericidal effect on Staphylococcus aureus at a concentration of 0.83 μg/μl, on Escherichia coli at a concentration of 3.33 μg/μl, on Pseudomonas aeruginosa at a concentration of 0.83 μg/μl, on Streptococcus pneumoniae at a concentration of 1.67 μg/μl, on a clinical isolate of Staphylococcus haemolyticus at a concentration of 26.65 μg/μl, on Staphylococcus saprophyticus at a concentration of 6.67 μg/μl, and against Klebsiella pneumoniae at a concentration of 13.36 μg/μl. The test result showed that the extract also has fungicidal activity against the test culture of Candida albicans at a concentration of 0.21 μg/μl. At tests, the disc diffusion method proved that the extract has antimicrobial activity with high values of the growth suppression zone exceeding 15 mm. The zones of growth retardation of the test strains were 19.33 ± 1.15 for Staphylococcus aureus; 17.33 ± 3.21 for Escherichia coli; 15.67 ± 0.57 for Pseudomonas aeruginosa; 20.0 ± 1.0 for Streptococcus pneumoniae; 16.0 ± 2.64 for Klebsiella pneumoniae; 15.0 ± 1.0 for Staphylococcus saprophyticus, and 22.0 ± 1.73 for Candida albicans. In relation to the clinical isolate of Staphylococcus haemolyticus, the extract has a bacteriostatic effect.