Distribution of free-living amoebae in a treatment system of textile industrial wastewater.

Free-living amoebae have been found in soil, air and a variety of aquatic environments, but few studies have been conducted on industrial wastewater and none on wastewater from the textile industry. The aim of this study was to determine the presence and distribution of free-living amoebae in a biological treatment system that treats textile industrial wastewater. Samples were taken from input, aeration tank, sedimentation tank and output. Samples were centrifuged at 1200g for 15min, the sediment was seeded on non-nutritive agar with Enterobacter aerogenes (NNE) and the plates were incubated at 30 and 37°C. Free-living amoebae were present in all stages of the treatment system. The highest number of amoebic isolates was found in the aeration tank and no seasonal distribution was observed during the year. A total of 14 amoeba genera were isolated: Acanthamoeba, Echinamoeba, Korotnevella, Mayorella, Naegleria, Platyamoeba, Saccamoeba, Stachyamoeba, Thecamoeba, Vahlkampfia, Vannella, Vermamoeba, Vexillifera and Willaertia. The most frequently found amoebae were Acanthamoeba and Vermamoeba which were found in all treatment system stages. The constant presence and diversity of free-living amoebae in the treatment system were important findings due to the characteristics of the wastewater from the textile plant in terms of the residue content from colorants, fixers, carriers, surfactants, etc., used in fabric dyeing and finishing processes. The factors that determined the presence and distribution of amoebae in the activated sludge system were their capacity to form cysts, which allowed them to resist adverse conditions; food availability; an average temperature of 27-33°C; dissolved oxygen in average concentrations above 2mg/L, and pH in a range of 5.9-7.1.

Free-living amoebae isolated from water-hyacinth root (Eichhornia crassipes).

Free-living amoebae are widely distributed in aquatic environments and their hygienic, medical and ecological relationships to man are increasingly important. The purpose of this study was to isolate free-living amoebae from water-hyacinth root (Eichhornia crassipes) and the water of an urban lake in Mexico City. Five grams of wet root were seeded on non-nutritive agar with Enterobacter aerogenes (NNE). Water samples were concentrated by centrifugation at 1200g for 15min and the pellet was seeded on NNE. Of the 16 isolated genera, 10 were detected in both habitats. The most frequent were Vannella in root and Acanthamoeba and Naegleria in water. The total number of isolates and genera isolated from root was higher than that isolated from water. The differences between root and water are probably due to the morphological characteristics of water-hyacinth root, which provides a large habitat and refuge area for many organisms.

Calidad bacteriológica del agua utilizada en clínicas odontológicas / Bacteriological quality of the water used in dental clinics

Se evaluó la calidad bacteriológica del agua de 8 clínicas odontológicas de la FESI UNAM, determinándose Coliformes fecales y Coliformes totales, por medio de la técnica de filtro de membrana. Realizándose de 2 a 4 muestreos semanales, en cada clínica se tomaron muestras de la jeringa triple y el llena vasos de 10 unidades dentales, además del suministro de entrada. Se tomaron 188 muestras, a cada una se le efectuaron 2 determinaciones (Coliformes totales y Coliformes fecales), haciendo un total de 376 análisis. De las muestras analizadas únicamente 8 presentaron contaminación bacteriana; 7 correspondieron al primer muestreo realizado en la Clínica de Acatlán después de un periodo vacacional; la contaminación fue consecuencia del prolongado estancamiento del agua debido a la inactividad clínica, lo cual contribuyó a la presencia de Coliformes fecales y Coliformes totales. Posteriormente a ese periodo vacacional los siguientes muestreos salieron negativos. En la clínica Ecatepec una muestra proveniente de una unidad dental que contaba con el sistema Flush, también resultó positiva para Coliformes totales. En las clínicas odontológicas se atiende anualmente más de 30,000 pacientes de diversas edades y estados de salud, a quienes se efectúan diversos tratamientos odontológicos que van desde extracciones hasta cirugías maxilofaciales.

The bacteriological quality of the water of 8 dental clinics of FESI UNAM, was evaluated determining total and fecal coliforms, by means of the technique of membrane filter. They were made 2 to 4 weekly samplings, and in each clinic, were taken samples of the triple syringe and the flood glasses of 10 dental units, in addition water tap. 188 samples were taken and both determinations of coliforms were made to each sample, making a total of 376 analyses. From all the analyzed samples only 8 presented bacterial pollution; 7 of them, corresponded to the first sampling made in Acatlán clinic after a vacational period; the pollution was consequence of the prolonged water stagnation due to the clinical inactivity, which contributed to the presence of fecal and total coliforms. After vacations the following samplings were negatives. In Ecatepec clinic one sample which came from a dental unit that with a Flush system, also was positive for total coliforms. The dental clinics, annually give service of more than 30.000 patients of diverse ages and states of health, offering diverse types of dental treatments since extractions to some maxilofacial surgeries. It was conclude that in general, the bacteriological quality of the water used in the dental clinics is good, which is very important, because water makes directly contact with the mucous membrane of oral cavity, dental structures, blood and saliva of the patient, avoiding infectious processes that could put in risk their integral health.