Streptophyta and Acetic Acid Bacteria Succession Promoted by Brass in Slow Sand Filter System Schmutzdeckes.

Macro- and microorganism activities are important for the effectiveness of the slow sand filtration (SSF), where native microorganisms remove contaminants mainly by substrate competition, predation, and antagonism. The aim of the present study was to evaluate the addition of the oligodynamic metals iron, copper, and brass, inserted separately into SSF to enhance pollutant removal in water samples. Four laboratory-scale SSFs were built and tested: control, iron, copper, and brass. Water analysis included physicochemical evaluation, total and fecal coliform quantification. An analysis on microbial communities in the SSFs schmutzdecke was achieved by using 16S rRNA amplification, the Illumina MiSeq platform, and the QIIME bioinformatics software. The results demonstrated that inorganic and organic contaminants such as coliforms were removed up to 90%. The addition of metals had no significant effect (p > 0.05) on the other parameters. The microbial community analysis demonstrated different compositions of the SSF with brass-influent, where the eukaryote Streptophyta was predominant (31.4%), followed by the acetic acid bacteria Gluconobacter (24.6%), and Acetobacteraceae (7.7%), these genera were absent in the other SSF treatments. In conclusion, the use of a SSF system can be a low cost alternative to reduce microbial contamination in water and thus reduce gastrointestinal diseases in rural areas.

Multidrug-Resistant Bacteria Isolated from Surface Water in Bassaseachic Falls National Park, Mexico.

Bacterial pathogens are a leading cause of waterborne disease, and may result in gastrointestinal outbreaks worldwide. Inhabitants of the Bassaseachic Falls National Park in Chihuahua, Mexico show seasonal gastroenteritis problems. This aim of this study was to detect enteropathogenic microorganisms responsible for diarrheal outbreaks in this area. In 2013, 49 surface water samples from 13 selected sampling sites along the Basaseachi waterfall and its main rivers, were collected during the spring, summer, autumn, and winter seasons. Fecal and total coliform counts were determined using standard methods; the AutoScan-4 system was used for identification of isolates and the antibiotic resistance profile by challenging each organism using 21 antibiotics. Significant differences among seasons were detected, where autumn samples resulted in the highest total (p < 0.05) and fecal (p < 0.001) coliform counts, whereas the lowest total coliform counts were recorded in spring. Significant differences between sampling sites were observed, where samples from sites 6, 8, and 11 had the highest total coliform counts (p < 0.009), whereas samples from site 9 exhibited the lowest one. From the microbiological analysis, 33 bacterial isolates from 13 different sites and four sampling seasons were selected; 53% of isolates were resistant to at least one antibiotic, and 15% exhibited a multidrug resistance (MDB) phenotype. MDB were identified as Klebsiella oxytoca (two out of four identified isolates), Escherichia coli (2/7), and Enterobacter cloacae (1/3). In addition, some water-borne microorganisms exhibited resistance to cefazoline, cefuroxime, ampicillin, and ampicillin-sulbactam. The presence of these microorganisms near rural settlements suggests that wastewater is the contamination source, providing one possible transmission mechanism for diarrheal outbreaks.

Identification of novel gene targets and putative regulators of arsenic-associated DNA methylation in human urothelial cells and bladder cancer.

There is strong epidemiologic evidence linking chronic exposure to inorganic arsenic (iAs) to myriad adverse health effects, including cancer of the bladder. We set out to identify DNA methylation patterns associated with arsenic and its metabolites in exfoliated urothelial cells (EUCs) that originate primarily from the urinary bladder, one of the targets of arsenic-induced carcinogenesis. Genome-wide, gene-specific promoter DNA methylation levels were assessed in EUCs from 46 residents of Chihuahua, Mexico, and the relationship was examined between promoter methylation profiles and the intracellular concentrations of total arsenic and arsenic species. A set of 49 differentially methylated genes was identified with increased promoter methylation associated with EUC tAs, iAs, and/or monomethylated As (MMAs) enriched for their roles in metabolic disease and cancer. Notably, no genes had differential methylation associated with EUC dimethylated As (DMAs), suggesting that DMAs may influence DNA methylation-mediated urothelial cell responses to a lesser extent than iAs or MMAs. Further analysis showed that 22 of the 49 arsenic-associated genes (45%) are also differentially methylated in bladder cancer tissue identified using The Cancer Genome Atlas repository. Both the arsenic- and cancer-associated genes are enriched for the binding sites of common transcription factors known to play roles in carcinogenesis, demonstrating a novel potential mechanistic link between iAs exposure and bladder cancer.

Actividad de la acetilcolinesterasa durante el embarazo y en el recién nacido / Acetylcholinesterase activity during pregnancy and on newborn

Objetivo. Determinar la actividad de la acetilcolinesterasa (AChE) en mujeres durante el embarazo y en el recién nacido y medir la correlación entre la actividad enzimática de muestras de sangre venosa y capilar. Material y métodos. Se incluyeron 205 pacientes (28 mujeres no embarazadas, 22, 25, 36 en el primero, segundo y tercer trimestre de la gestación respectivamente, 65 en trabajo de parto y 29 recién nacidos). Se excluyeron pacientes con diagnóstico de preeclampsia, eclampsia, diabetes mellitus, asma bronquial o con exposición expresa a plaguicidas inhibidores de colinesterasas. Se realizó un análisis de diferencias de medias tomando como referencia el grupo de mujeres sanas no embarazadas y mediante un análisis bivariado se analizaron los factores que pueden modificar la actividad enzimática.Resultados. La actividad de acetilcolinesterasa en mujeres sanas no embarazadas fue de 4.59 ñ 0.79 U/mL, y fue significativamente mayor durante el tercer trimestre de la gestación (4.98 ñ 0.87 U/mL) y en el trabajo de parto (5.75 ñ 1.15 U/mL). En recién nacidos se observó una actividad de 3.78 ñ 0.56 U/mL. No se encontró diferencia significativa de la actividad enzimática en el análisis bivariado según tabaquismo, índice de masa corporal, uso de insecticidas en el hogar o niveles de hemoglobina. Conclusión. Se han establecido los valores de referencia de la actividad de la AchE durante el embarazo y podrán ser utilizados en mujeres con características similares para determinar el efecto de la exposición a plaguicidas inhibidores de colinesterasas.