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Castaneda-Ruelas G.,Autonomous University of Sinaloa | Eslava-Campos C.,National Autonomous University of Mexico | Eslava-Campos C.,Laboratorio Of Patogenicidad Bacteriana | Campo N.C.,Research Center en Alimentacion y Desarrollo | And 2 more authors.
Salud Publica de Mexico | Year: 2014

Listeriosis is caused by Listeria monocytogenes, an important food-borne disease due to its clinical forms, high mortality rate, and the economic impact in both clinical and food production industries. In Mexico, the lack of epidemiological surveillance systems leads to the need of accurate data on the incidence of listeriosis and its association with food-borne disease. In this paper, we present data about the presence of this bacterium in food, reports related to clinical cases of listeriosis, and information of diseases in which L. monocytogenes may be involved. However, in most of these cases the etiology was not established. Given this, therés a need to inform and warn the appropriate entities, to define strategies for the mandatory search of L. monocytogenes through the whole food production chain and clinical suspects, for the epidemiological importance and control of listeriosis in Mexico.

Cruz-Cordova A.,Laboratorio Of Investigacion En Bacteriologia Intestinal | Espinosa-Mazariego K.,Laboratorio Of Investigacion En Bacteriologia Intestinal | Ochoa S.A.,Laboratorio Of Investigacion En Bacteriologia Intestinal | Saldana Z.,Laboratorio Of Investigacion En Bacteriologia Intestinal | And 13 more authors.
Frontiers in Microbiology | Year: 2014

Background: Enterotoxigenic Escherichia coli (ETEC) colonize the human intestinal mucosa using pili and non-pili colonization factors (CFs). CS21 (also designated Longus) is one of the most prevalent CFs encoded by a 14 kb lng DNA cluster located in a virulence plasmid of ETEC; yet limited information is available on the prevalence of CS21 positive ETEC isolates in different countries. The aim of this study was to evaluate the prevalence of CS21 among ETEC clinical isolates from Mexican and Bangladeshi children under 5 years old with diarrhea and to determine the phenotypic and genotypic features of these isolates. Methods: ETEC clinical isolates positive to lngA gene were characterized by genotype, multidrug-resistance, self-aggregation, biofilm formation, and adherence to HT-29 cell line. Results: A collection of 303 E. coli clinical isolates were analyzed, the 81.51% (247/303) were identified as ETEC, 30.76% (76/247) were st+/lt+, and 25.10% (62/247) were positive for the lngA gene. Among the lngA+ ETECs identified, 50% of isolates (31/62) were positive for LngA protein. The most frequent serotype was O128ac:H12 found in 19.35% (12/62) of lngA+ ETEC studied. Multidrug-resistance (MDR) lngA+ ETEC isolates was identified in 65% (39/60), self-aggregation in 48.38% (30/62), and biofilm formation in 83.87% (52/62). ETEC lngA+ isolates were able to adhere to HT-29 cells at different levels. Two lngA isogenic mutants were constructed in the ETEC E9034A and ETEC73332 clinical isolate, showing a 77% and 98% reduction in adherence, respectively with respect to the wild type. Conclusion: ETEC isolates that have the lngA gene showed features associated with self-aggregation, and adherence to HT-29 cells, important characteristics in the human gut colonization process and pathogenesis. © 2014 2014 Cruz-Córdova, Espinosa-Mazariego, Ochoa, Saldaña, Rodea, Cázares-Domínguez, Rodríguez-Ramírez, Eslava-Campos, Navarro-Ocaña, Arrellano-Galindo, Hernández-Castro, Gómez-Duarte, Qadri and Xicohtencatl-Cortes.

Chavez F.,University of Concepcion | Aranda M.,University of Concepcion | Garcia A.,Laboratorio Of Patogenicidad Bacteriana | Pastene E.,University of Concepcion
Boletin Latinoamericano y del Caribe de Plantas Medicinales y Aromaticas | Year: 2011

Chronic infection by Helicobacter pylori produce chronic gastritis leading to other more severe pathologies as peptic ulcer and gastric adenocarcinoma. New anti-H. pylori agents has been found in natural products, particularly polyphenols. The inhibition of enzymes such us urease appears to be an interesting strategy by which polyphenols could limit the colonization by H. pylori. From the exocarp of Persea americana (avocado fruit), we obtain a procyanidin-rich extract with a 77% of gallic acid equivalents (GAE). Such procyanidins derived from epicatechin. with a mean degree of polymerization DPm = 6.10. The antioxidant capacity was assessed by different methods as TEAC-DPPH, TEAC-CUPRAC, TEAC-FRAP, TEAC-crocin. The extract shown inhibitory activity against H. pylori urease with an IC50 = 1.02 μg GAE/mL. In order to obtain clusters of procyanidins with different molecular weights, avocado peel extract was fractioned. A clear relation between the molecular size of procyanidins and their urease inhibitory activity was observed. © 2011 Boletín Latinoamericano y del Caribe de Plantas Medicinales y Aromáticas.

Rocha-Ramirez L.M.,Hospital Infantil de Mexico Federico Gomez | Hernandez-Chinas U.,National Autonomous University of Mexico | Hernandez-Chinas U.,Laboratorio Of Patogenicidad Bacteriana | Banos-Rojas D.,Hospital Infantil de Mexico Federico Gomez | And 6 more authors.
BMC Microbiology | Year: 2016

Background: Pet is a toxin from the family of Serine Protease Autotransporters of Enterobacteriaceae which was initially identified in Enteroaggregative Escherichia coli strains. This protease exhibits enterotoxin properties, damages the cell cytoskeleton and induces intestinal epithelium alterations, which are associated with a severe inflammatory process. An in-vitro study was conducted to evaluate the effect of Pet on the migration of human peripheral blood monocytes-derived macrophages and its participation in the activation of the early inflammatory response and cytokine expression. Results: In the macrophage migration activation assay, Pet produced a similar effect to that induced by opsonized zymosan (ZAS). Regarding the cytokine expression, an increase of IL-8, TNF-α (pro-inflammatory) and IL-10 (anti-inflammatory) was identified. In addition to the above results, the nuclear translocation of NF-kB pp65 was also identified. These events are probably related to the inflammatory response identified in the histological examination of intestine rat samples inoculated with Pet during a ligated loop assay. Conclusion: The results showed that Pet participates as an immunostimulant molecule for macrophages, which activates both their mobility and cytokine expression. These observations suggest that the toxin participates in the inflammatory process that is observed during the host infection by EAEC Pet producing. © 2016 The Author(s).

Domingo Meza-Aguilar J.,National Autonomous University of Mexico | Domingo Meza-Aguilar J.,Laboratorio Of Patogenicidad Bacteriana | Fromme P.,Arizona State University | Torres-Larios A.,National Autonomous University of Mexico | And 7 more authors.
Biochemical and Biophysical Research Communications | Year: 2014

Autotransporters (ATs) represent a superfamily of proteins produced by a variety of pathogenic bacteria, which include the pathogenic groups of Escherichia coli (E. coli) associated with gastrointestinal and urinary tract infections. We present the first X-ray structure of the passenger domain from the Plasmid-encoded toxin (Pet) a 100 kDa protein at 2.3 Å resolution which is a cause of acute diarrhea in both developing and industrialized countries. Pet is a cytoskeleton-altering toxin that induces loss of actin stress fibers. While Pet (pdb code: 4OM9) shows only a sequence identity of 50% compared to the closest related protein sequence, extracellular serine protease plasmid (EspP) the structural features of both proteins are conserved. A closer structural look reveals that Pet contains a β-pleaded sheet at the sequence region of residues 181-190, the corresponding structural domain in EspP consists of a coiled loop. Secondary, the Pet passenger domain features a more pronounced beta sheet between residues 135 and 143 compared to the structure of EspP. © 2014 Elsevier Inc. All rights reserved.

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