Fifty Acinetobacter isolates were obtained from urinary tract infections and urinary catheter samples. Analytical profile index assays identified 47 isolates as Acinetobacter baumannii and three as Acinetobacter lwoffii. Six A. baumannii isolates (A1-A6) displayed hydrophobicity indices >70%. Twenty isolates exhibited lectin activity. Biofilm formation by these isolates was compared with those with low hydrophobicity index values (A45-A50). Biofilms on different surfaces were confirmed by light microscopy, epifluorescence microscopy and by obtaining scanning electron microscope images. Biofilm production was maximal at 30 °C, pH 7.0 in a medium with 5.0 g L(-1) NaCl, and its efficiency was reduced on urinary catheter surfaces at sub-minimum inhibitory concentration concentrations of colistin. Plasmid-mediated antibiotic resistance was observed in selected isolates of A. baumannii and experiments of conjugation and transformation showed the occurrence of gene transfer. Plasmid curing was used to examine the function of plasmids. Five plasmids of A. baumannii A3 were cured but no differences were observed between wild-type and plasmid-cured strains with respect to the biofilm formation capabilities. The prevalence of A. baumannii strains with biofilm mode of growth could explain their ability to persist in clinical environments and their role in device-related infections.

Jarosite is an effective scavenger for metals by the chemical formula AFe3(SO4)2(OH)6. In the present article, a comprehensive literature review is performed on the formation, decomposition, and utilization of jarosite. Based on reviewed studies, biological jarosite seeds can shorten the induction period and reduce the temperature limit in the jarosite precipitation. Also, the precipitation process of jarosite is more complete with biological jarosite seeds. The crystallization parameters such as Fe2(SO4)3 concentration, agitation speed, pH and temperature have significantly affected on the morphology and the particles size of jarosite. Decomposition of jarosite is carried out using two different methods thermal and hydrothermal. Jarosite seed is a potential resource, which has to be recycled in a technically feasible and environmentally friendly manner. Besides, it is observed that jarosites have several advantages such as control iron in hydrometallurgy, zinc industry, arsenic removal and other impurities, pigment, nanoparticles, filling materials, adsorption materials, acidic reagent, and catalytic materials.

Background and Aims: Assessment of the extend role of dominant serotyprs of Listeria monocytogenes in spontaneous abortions, using isolation methods and PCR(Polymerase Change Reaction) analysis for the presence of dominant serotypes such as 1/2a, 4b. Materials and Methods: A total of 258 samples comprising placental bits, vaginal swabs and blood were collected from out of 123 patients with spontaneous abortion. Listeria monocytogenes was identified and confirmed by culture, biochemical, serological tests, API system, CAMP (Christie, Atkins, Munch and Petersen), hemolysis on sheep blood agar. PI-PLC (Phosphatidyl Inositol specific Phospholipase C) assay, followed by Multiplex PCR to detection of serotypes 1/2a and 4b. Result: Out of 258 samples, 28 isolates of Listeria monocytogenes were identified   by different methods. All of the isolates were confirmed by PCR. Our search indicated that from 123 patients, 28 of isolated (46.6%)  Listeria monocytogenes strains, 14(50%) belonged to serovar 1/2a, 10(35%) to serovar 4b and 4(14.2%) to other serovars respectively. Conclusions: Based on our study, serovars 1/2a and 4b play a key role in human spontaneous abortion. Data analysis also showed that these serovars (1/2a, 4b) are dominant serovars as causative agents of the spontaneous abortion in pregnant women.

La disminución de la concentración de iones de hierro de una solución de refinado procedente de la extracción con solvente de cobre es importante para mantener una buena eficiencia de corriente en el proceso de electrolisis. En este estudio, se investigaron los efectos combinados de la “semilla” de jarosita biosintética y Acidithiobacillus ferrooxidans sobre la eliminación de hierro de la solución de refinado de cobre y el efecto del pH. La biosíntesis de “semillas” de jarosita de amonio se realizó de manera eficiente a pH 2 y una concentración de Fe2 + de 50 g·l-1. El porcentaje de eliminación de hierro de la solución de refinado a un pH de 1,5; 2,5 y 5% de dosis de semillas fue de 0,81%, 47,38% y 71,26%, respectivamente. La concentración de hierro en la solución de refinado disminuyó notablemente hasta alcanzar un valor del 71,17% con la incorporación de un 10% en peso de “semilla” de jarosita junto con un 10% V/V de A. ferrooxidans. Esto se debió al aumento en la superficie específica de los sólidos en la solución y a las características magnéticas de A. ferrooxidans que promueven la eliminación de hierro. Se seleccionó un pH 2 y una carga de “semillas” de jarosita del 10% como las condiciones óptimas para la eliminación del hierro de la solución de refinado. Se concluyó que se podría incrementar la recuperación de cobre del refinado biológicamente refinado.