title: Analysis of the Bacterial Diversity in Liver Abscess: Differences Between Pyogenic and Amebic Abscesses.
abstract: Several recent studies have demonstrated that virulence in Entamoeba histolytica is triggered in the presence of both pathogenic and nonpathogenic bacteria species using in vitro and in vivo experimental animal models. In this study, we examined samples aspirated from abscess material obtained from patients who were clinically diagnosed with amebic liver abscess (ALA) or pyogenic liver abscess (PLA). To determine the diversity of bacterial species in the abscesses, we performed partial 16S rRNA gene sequencing. In addition, the E. histolytica and Entamoeba dispar species were genotyped using tRNA-linked short tandem repeats as specific molecular markers. The association between clinical data and bacterial and parasite genotypes were examined through a correspondence analysis. The results showed the presence of numerous bacterial groups. These taxonomic groups constitute common members of the gut microbiota, although all of the detected bacterial species have a close phylogenetic relationship with bacterial pathogens. Furthermore, some patients clinically diagnosed with PLA and ALA were coinfected with E. dispar or E. histolytica, which suggests that the virulence of these parasites increased in the presence of bacteria. However, no specific bacterial groups were associated with this effect. Together, our results suggest a nonspecific mechanism of virulence modulation by bacteria in Entamoeba.
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), México City, México; Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), México City, México.
authors.forename: Miriam E
authors.initials: ME
authors.lastname: Reyna-Fabián
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), México City, México; Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), México City, México.
authors.forename: Valeria
authors.initials: V
authors.lastname: Zermeño
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), México City, México; Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), México City, México cximenez@unam.mx renecerritos@gmail.com.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Ximénez
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), México City, México; Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), México City, México.
authors.forename: Janin
authors.initials: J
authors.lastname: Flores
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), México City, México; Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), México City, México.
authors.forename: Miguel F
authors.initials: MF
authors.lastname: Romero
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), México City, México; Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), México City, México.
authors.forename: Daniel
authors.initials: D
authors.lastname: Diaz
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), México City, México; Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), México City, México.
authors.forename: Jesús
authors.initials: J
authors.lastname: Argueta
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), México City, México; Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), México City, México.
authors.forename: Patricia
authors.initials: P
authors.lastname: Moran
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), México City, México; Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), México City, México.
authors.forename: Alicia
authors.initials: A
authors.lastname: Valadez
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), México City, México; Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), México City, México cximenez@unam.mx renecerritos@gmail.com.
authors.forename: René
authors.initials: R
authors.lastname: Cerritos
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D004748:Entamoeba histolytica / Q000145:classification; D005838:Genotype; D006801:Humans; D008101:Liver Abscess, Amebic / Q000382:microbiology / Q000469:parasitology*; D046290:Liver Abscess, Pyogenic / Q000382:microbiology*; D010802:Phylogeny
chemical_list: D004269:DNA, Bacterial