Adsorption of different forms of phosphorus on modified corn bracts.

Excessive phosphorus discharged into the environment could result in the eutrophication, leading to water pollution. Hence, the efficient method for phosphorus removal is urgently in need. In this paper, an agricultural by-product, corn bract, modified by Zr was proposed to remove different forms of phosphorus. A comparison study about the adsorption performance of organic phosphorus (OP) and inorganic phosphorus (IP) was investigated. The results indicated that both the OP and IP reached the maximum adsorption amounts when the initial pH was 2. Compared with IP adsorption, the adsorbent showed higher adsorption rate but lower adsorption capacity for OP. The complexation and the electrostatic attraction were possibly the main adsorption mechanisms. PRACTITIONER POINTS: The agricultural waste, corn bract, was proposed to remove phosphorus. The adsorption performances of OP and IP were compared. The adsorbent showed higher adsorption rate but lower adsorption capacity for OP.

Resistencia antimicrobiana en aislados clínicos de Pseudomonas aeruginosa / Antimicrobial resistance in clinical patterns of Pseudomonas aeruginosa

Pseudomonas aeruginosa es un microorganismo oportunista frecuentemente implicado en infecciones de origen nosocomial que presenta resistencia natural y adquirida a muchos de los antimicrobianos de uso clínico. Se llevo a cabo un estudio de resistencias a antimicrobianos de 3.029 aislamientos de P. aeruginosa de enfermos intra y extrahospitalarios en el periodo 2005-2010. La metodología utilizada fue, el método semiautomatizado WIDER I (Soria Melguizo), para la identificación de las especies y para el estudio de sensibilidades a antimicrobianos. Se consideraron los criterios de sensibilidad y resistencia recomendados por el grupo MENSURA. En nuestro hospital existe un mantenimiento relativo de la sensibilidad antimicrobiana de P. aeruginosa en el periodo 2005-2010, con un aumento de esta en amikacina, gentamicina y cefalosporinas. Existen diferencias de porcentajes de sensibilidades entre las cepas de origen intrahospitalario y extrahospitalario, salvo para fosfomicina y tobramicina. Destacamos la importancia de realizar estudios locales de la sensibilidad y resistencias de P. aeruginosa en cada zona, de forma periódica para poder valorar las diferentes pautas terapéuticas, no siendo posible extrapolar los datos de las diferentes regiones españolas(AU)

Pseudomonas aeruginosa is an opportunistic microorganism that is frequently the cause of nosocomial infections. Multiple mechanisms are involved in its natural and acquired resistance to many of the antimicrobial agents commonly used in clinical practice. We performed an antibiotic resistance study on P. aeruginosa isolated from intrahospitalary and extrahospitalary samples between 2005 and 2010 years. We included in the study a global amount of 3,029 P. aeruginosa isolates from clinical samples received at University Hospital Reina Sofia. Microbiology Service in Córdoba (Spain). Semiautomatic system WIDER I for strains identification and sensibility testing was employed. We considered susceptibility and resistance criteria recommended by MENSURA group. Results of the analysis showed that P. aeruginosa maintanied similar levels of antimicrobial susceptibility during the period 2005-2010, with increased susceptibility to amikacin, gentamicin and cefalosporins. There were also important differences in the degree of susceptibility between intrahospital and extrahospital strains during 2010 year, except for tobramicin and fosfomycin. The intrahospital difference in susceptibility was also evaluated, emphasizing the importance of periodically surveillance of susceptibility and resistance patterns of P. aeruginosa, in each setting in order to evaluate different therapeutic guidelines, because it is not always advisable to extrapolate data from different regions(AU)

Etiología y resistencia bacteriana de las infecciones urinarias extrahospitalarias del norte de Tenerife / Etiology and antibacterial resistances of urinary infection of outpatients in north of Tenerife

Objectivo. Conocer los microorganismos causantes de las infecciones urinarias extrahospitalarias y sus resistencias antimicrobianas en nuestra área para facilitar el tratamiento antibiótico de forma empírica. Diseño. Se describen las infecciones del tracto urinario (ITU) identificadas a partir de la revisión sistemática de los resultados de urianálisis y urocultivo realizados en nuestro laboratorio. Pacientes y métodos. Urocultivos solicitados y remitidos a nuestro laboratorio entre los meses de abril a noviembre de 2003. Se identificó el tipo de germen y la sensibilidad antibiótica. Se analizaron un total de 4.874 urocultivos, de los cuales 1.310 (27 por ciento) fueron positivos. El germen más prevalente fue E. coli (48 por ciento) con mayor sensibilidad a fosfomicina, nitrofurantoína y amoxicilinaclavulánico, seguido de E. faecalis (14 por ciento), P. mirabilis (4 por ciento) y K. pneumoniae (3 por ciento). Conclusiones. E. coli fue el germen más frecuentemente aislado. Considerando una tasa de resistencia inferior al 20 por ciento para el empleo empírico de antibióticos en las ITU no complicadas, no se recomienda el uso de ampicilina, cotrimoxazol y quinolonas. En nuestro medio, los antibióticos de elección para el tratamiento de ITU serían amoxicilina-clavulánico y cefalosporinas de primera generación (AU)

Fosfadecin and fosfocytocin, new nucleotide antibiotics produced by bacteria.

Two new nucleotide antibiotics, fosfadecin and fosfocytocin, have been isolated from the culture filtrates of Pseudomonas viridiflava PK-5 and Pseudomonas fluorescens PK-52, respectively. These antibiotics were purified by column chromatographies using adsorption, gel filtration and ion exchange resins. On the basis of the spectroscopic and degradation studies, the chemical structures of fosfadecin and fosfocytocin were determined. These antibiotics were either enzymatically or chemically hydrolyzed to generate fosfomycin and a new antibiotic, fosfoxacin, which are also produced in the culture filtrates. They showed antibacterial activity against Gram-positive and Gram-negative bacteria. The antibacterial activity of these nucleotide antibiotics was weaker than that of fosfomycin and fosfoxacin.

Studies on new phosphonic acid antibiotics. I. FR-900098, isolation and characterization.

A strain of Streptomyces, isolated from a soil sample and identified as Streptomyces rubellomurinus sp. nov., has been found to produce FR-900098, an interesting new antibiotic containing phosphorus in its molecule. The antibiotic, obtained as colorless crystals, was shown to inhibit a wide variety of Gram-negative bacteria including Pseudomonas, Proteus, and Escherichia coli. Its antibacterial action involves interference with bacterial cell wall synthesis as evidenced by the fact that it causes spheroplast formation by susceptible cells.

Studies on new phosphonic acid antibiotics. III. Isolation and characterization of FR-31564, FR-32863 and FR-33289.

Three phosphonic acid antibiotics were found to be produced in the fermentation broths of Streptomyces. FR-31564 and FR-32863 were produced by Streptomyces lavendulae. FR-33289 was produced by a strain of Streptomyces, identified as Streptomyces rubellomurinus subsp. indigoferus. They are distinct from, but resemble FR-900098 which was reported in our preceding paper, in their chemical and biological characteristics.