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Garcia-Mena J.,National Polytechnic Institute of Mexico | Murugesan S.,National Polytechnic Institute of Mexico | Perez-Munoz A.A.,National Polytechnic Institute of Mexico | Garcia-Espitia M.,Escuela Nacional de Medicina y Homeopatia del IPN | And 9 more authors.
Microbial Ecology | Year: 2016

Greater Mexico City is one of the largest urban centers in the world, with an estimated population by 2010 of more than 20 million inhabitants. In urban areas like this, biological material is present at all atmospheric levels including live bacteria. We sampled the low atmosphere in several surveys at different points by the gravity method on LB and blood agar media during winter, spring, summer, and autumn seasons in the years 2008, 2010, 2011, and 2012. The colonial phenotype on blood agar showed α, β, and γ hemolytic activities among the live collected bacteria. Genomic DNA was extracted and convenient V3 hypervariable region libraries of 16S rDNA gene were high-throughput sequenced. From the data analysis, Firmicutes, Proteobacteria, and Actinobacteria were the more abundant phyla in all surveys, while the genera from the family Enterobacteriaceae, in addition to Bacillus spp., Pseudomonas spp., Acinetobacter spp., Erwinia spp., Gluconacetobacter spp., Proteus spp., Exiguobacterium spp., and Staphylococcus spp. were also abundant. From this study, we conclude that it is possible to detect live airborne nonspore-forming bacteria in the low atmosphere of GMC, associated to the microbial cloud of its inhabitants. © 2016 Springer Science+Business Media New York

Lopez-Camarillo C.,National Autonomous University of Mexico | de la Cruz O.N.H.,National Autonomous University of Mexico | Vivas J.G.,Escuela Nacional de Medicina y Homeopatia del IPN | Retana J.F.,Escuela Nacional de Medicina y Homeopatia del IPN | And 4 more authors.
Infectious Disorders - Drug Targets | Year: 2010

The messenger RNA precursors (pre-mRNA) 3 ́-end processing occurs in a two-step co-transcriptional coupled reaction, denoted as cleavage and polyadenylation. Both processes depend on trans-acting factors interacting in a coordinated manner with cis-sequence motifs located at the 3 ́ untranslated region of transcripts. In this paper, we reviewed mechanisms involved in pre-mRNA processing in eukaryotic organisms, including our own findings about sequences and proteins potentially involved in mRNA 3 ́-end formation in the protozoan parasite Entamoeba histolytica. Interestingly, protein sequence comparisons among E. histolytica, yeast, and human pre-mRNA processing machineries showed that amoeba pre-mRNA 3 ́-end processing machinery appears to be in an intermediate evolutionary position between mammals and yeast. In addition, the presence of non canonical poly(A) polymerases family recently identified in E. histolytica, adds more complexity to the mRNA 3 ́-end formation process in this ancient eukaryote. © 2010 Bentham Science Publishers Ltd.

Lpez-Reyes I.,CINVESTAV | Garcia-Rivera G.,CINVESTAV | Bauelos C.,CINVESTAV | Herranz S.,Institute Investigaciones Biomedicas CSIC UAM | And 4 more authors.
Journal of Biomedicine and Biotechnology | Year: 2010

Eukaryotic endocytosis involves multivesicular bodies formation, which is driven by endosomal sorting complexes required for transport (ESCRT). Here, we showed the presence and expression of homologous ESCRT genes in Entamoeba histolytica. We cloned and expressed the Ehvps4 gene, an ESCRT member, to obtain the recombinant EhVps4 and generate specific antibodies, which immunodetected EhVps4 in cytoplasm of trophozoites. Bioinformatics and biochemical studies evidenced that rEhVps4 is an ATPase, whose activity depends on the conserved E211 residue. Next, we generated trophozoites overexpressing EhVps4 and mutant EhVps4-E211Q FLAG-tagged proteins. The EhVps4-FLAG was located in cytosol and at plasma membrane, whereas the EhVps4-E211Q-FLAG was detected as abundant cytoplasmic dots in trophozoites. Erythrophagocytosis, cytopathic activity, and hepatic damage in hamsters were not improved in trophozoites overexpressing EhVps4-FLAG. In contrast, EhVps4-E211Q-FLAG protein overexpression impaired these properties. The localization of EhVps4-FLAG around ingested erythrocytes, together with our previous results, strengthens the role for EhVps4 in E. histolytica phagocytosis and virulence. Copyright © 2010 Israel Ĺopez-Reyes et al.

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