Adriana Bentancor | Universidad de Buenos Aires (original) (raw)

Papers by Adriana Bentancor

BENTHAM SCIENCE PUBLISHERS eBooks, Dec 2, 2010

Medicina-buenos Aires, 2006

Escherichia coli is an important constitutional element of both animal&amp;amp;amp;#39;s ... more Escherichia coli is an important constitutional element of both animal&amp;amp;amp;#39;s and men&amp;amp;amp;#39;s microbiote. Rumiants in general and bovine in particular have been pointed out as reservoirs of shigatoxigenic (STEC) and enterohemorragic strains (EHEC). These strains are rarely reported in pets isolations and are badly documented. Revisions of the pathogenic role of E. coli in small animals, particulary based on intestinal and urogenital isolations, involve in a very low proportion the STEC strains. In dogs, ocasional isolations are reported, from feces coming from both healthy and diarreic dogs. The STEC intestinal strains prevalence in dogs and cats from urban centers, based on the habit of including regular or ocasional raw meat in their diet, should not be understimated.

BioMed Research International, 2014

Twenty-one Escherichia coli O157:H7 strains isolated in northern Italy from sporadic cases of hem... more Twenty-one Escherichia coli O157:H7 strains isolated in northern Italy from sporadic cases of hemolyticuremic syndrome and from cattle and food were characterized by virulence gene analysis, pulsed-field gel electrophoresis (PFGE) of XbaI-digested DNA, enterobacterial repetitive intergenic consensus (ERIC) sequence-based PCR (ERIC-PCR), and antibiotic resistance patterns and compared to 18 strains isolated in France from human cases of diarrhea, cattle, and the environment. Strains isolated in Sicily (southern Italy) from a local farm (one strain) and from calves just imported from France (11 strains) and Spain (six strains) were also typed. Whereas the eae and hlyA genes were always detected, Shiga toxin gene (stx) analysis showed some differences related to geographic areas. Isolates from northern Italy showed a high frequency of stx 1 and stx 2 , while strains isolated in France and from French and Spanish calves imported to Sicily more frequently possessed the stx 2c gene. The majority of the strains isolated in northern Italy were also resistant to one or more antibiotics, while most of the strains isolated in France and Sicily were fully susceptible. ERIC-PCR analysis was not able to differentiate the strains. PFGE typing after XbaI DNA digestion produced a total of 54 distinct restriction endonuclease digestion profiles (REDPs) among the 57 strains. Phylogenetic analysis was unable to cluster REDPs according to geographic origin. All epidemiologically related isolates showed either identical or >91% similar REDPs. Our findings suggest a peculiar circulation of antibiotic-resistant, genetically unrelated strains in northern Italy.

Revista Argentina De Microbiologia, 2016

El síndrome urémico hemolítico (SUH), descripto por Conrad Gasser 2 en 1955, es una entidad nosol... more El síndrome urémico hemolítico (SUH), descripto por Conrad Gasser 2 en 1955, es una entidad nosológica caracterizada por anemia hemolítica microangiopática, trombocitopenia e insuficiencia renal. Este síndrome fue asociado a alimentos contaminados desde 1982 9 , pero es recién a fines de los 80 que Mohamed A. Karmali identifica a Escherichia coli productora de toxina Shiga (STEC) como el agente etiológico del SUH 4. En Argentina el SUH representa la primera causa de insuficiencia renal aguda en pediatría y es la segunda causa de insuficiencia renal crónica. A su vez, determina la necesidad de trasplante renal en el 20 % de los niños y los adolescentes.

Journal of Bacteriology & Mycology: Open Access

Objectives: The aim of this work is to evaluate ground meat as infection source of Shiga toxin-pr... more Objectives: The aim of this work is to evaluate ground meat as infection source of Shiga toxin-producing Escherichia coli (STEC) to population of Tierra del Fuego, Argentina. Background: Argentina is the country with the highest rate of hemolytic uremic syndrome (HUS). The main agent of HUS is STEC, which produce a food borne disease at a low infective dose (<100 CFU/g). Cattle is a natural reservoir of STEC, and ground meat is a high-risk food since surface contamination is distributed throughout the meat. Tierra del Fuego (TDF) is part of the patagonian region of Argentina, which presents the highest rate of hemolytic uremic syndrome (HUS). Methods: In our study, all of the butcher shops in the island were sampled. Ninety-three samples of ground meat were taken from butcher shops enabled in three TDF communities. Samples were processed in accordance of the algorithm for STEC O157 and non-O157 STEC. Results: A total of 2.15% of the samples of ground meat from the retail outlets ...

Fems Microbiology Letters, Oct 19, 2012

Atypical enteropathogenic Escherichia coli (aEPEC) is comprised of a large heterogeneous group of... more Atypical enteropathogenic Escherichia coli (aEPEC) is comprised of a large heterogeneous group of strains and serotypes that carry the intimin gene (eae) but no other EPEC virulence factors. In a previous study, we examined a few aEPEC strains of O157:H16 serotype from the U.S. and France and found these to be nearly homologous, and speculated that the same strain had been disseminated or perhaps they are part of a large clonal group that exists worldwide. To test that hypothesis, we examined additional 45 strains isolated from various sources from 4 other countries and determined that although there are a few eae-negative O157:H16 strains, most are aEPEC that carried eae and specifically, the e-eae allele. Analysis by pulsed field gel electrophoresis (PFGE) and multilocus sequence typing showed that as a whole, O157:H16 strains are phylogenetically diverse and have different sequence types and PFGE profiles. But the aEPEC strains within the O157:H16 serotype, regardless of the eae allele carried, are a highly conserved and homologous group of sequence type (ST)-171 strains that shared similar PFGE profiles. These aEPEC strains of O157:H16 serotype are not closely related to any of the major EPEC and enterohemorrhagic E. coli clonal lineages and appear to be part of a large clonal group that are prevalent worldwide.

Veterinary Microbiology, 2017

Problem addressed: Shiga toxin-producing Escherichia coli (STEC) are a group of bacteria responsi... more Problem addressed: Shiga toxin-producing Escherichia coli (STEC) are a group of bacteria responsible for food-associated diseases. Clinical features include a wide range of symptoms such as diarrhea, hemorrhagic colitis and the hemolytic uremic syndrome (HUS), a life-threatening condition. Objective: Our group has observed that animals naturally colonized with STEC strains of unknown serotype were not efficiently colonized with E. coli O157:H7 after experimental infection. In order to assess the basis of the interference, three STEC strains were isolated from STEC persistently-colonized healthy cattle from a dairy farm in Buenos Aires, Argentina. Methods and Results: The three isolated strains are E. coli O22:H8 and carry the stx1 and stx2d genes. The activatable activity of Stx2d was demonstrated in vitro. The three strains carry the adhesins iha, ehaA and lpfO113. E. coli O22:H8 formed stronger biofilms in abiotic surface than E. coli O157:H7 (eae+, stx2+) and displayed a more adherent phenotype in vitro towards HeLa cells. Furthermore, when both serotypes were cultured together O22:H8 could reduce O157:H7 adherence in vitro. When calves were intragastrically prechallenged with 10 8 CFU of a mixture of the three STEC strains and two days later challenged with the same dose of the strain E. coli O157:H7 438/99, the shedding of the pathogen was significantly reduced. Conclusions: These results suggest that E. coli O22:H8, a serotype rarely associated with human illness, might compete with O157:H7 at the bovine recto-anal junction, making non-O157 carrying-calves less susceptible to O157:H7 colonization and shedding of the bacteria to the environment.

Revista Jornadas de Investigación (2020);año 11, n° 11, Oct 1, 2020

Escherichia coli shigatoxigénico (STEC) es un patógeno emergente de presentación endémica señalad... more Escherichia coli shigatoxigénico (STEC) es un patógeno emergente de presentación endémica señalado como la principal etiología de síndrome urémico hemolítico. E. coli enteropatógeno (EPEC) constituye otro patovar de E. coli con impacto en la Salud Pública debido a que causa diarrea infantil potencialmente mortal. El objetivo del presente trabajo fue estudiar la persistencia de cepas STEC y EPEC en una matriz definida, arena, sometida a condiciones ambientales estresantes como calor, desecación y falta de nutrientes

Journal of Infection in Developing Countries, Nov 30, 2011

Introduction: Shiga toxin-producing Escherichia coli (STEC) infections are the leading cause of h... more Introduction: Shiga toxin-producing Escherichia coli (STEC) infections are the leading cause of hemolytic uremic syndrome (HUS). STEC is the most common cause of acute kidney disease, responsible for 20% of renal transplants in Argentina. Methodology: In 2007, an epidemiological survey was conducted among 883 students from the fifth and sixth years of elementary education in the public schools of San Martin City, Buenos Aires, Argentina. Degree of exposure to the known risk factors previously detected in the region as primary causes of STEC infections was evaluated. Risk factors assessed included consumption of hamburgers, poor personal hygiene, and exposure to various types of drinking and recreational water. The study was designed to evaluate exposure to risk factors for STEC infections among different socioeconomic groups. Results: Ninety-five percent of children surveyed reported consumption of hamburgers. Most of these hamburgers were precooked. Children of high and medium strata attended private swimming-pools, while children from the low stratum attended public pools. Only 30.2% of students washed their hands after going to the toilet and only 43.5% reported hand-washing before eating. Conclusions: Students demonstrated high levels of exposure to identified risk factors for STEC infections. Reduction of these risks will require cultural changes aimed at decreasing morbidity caused by food-borne infections. Institutional framework must provide the necessary resources to implement these changes and emphasize the importance of good personal hygiene. Health education must be implemented to increase food safety awareness of the consumers.

Brazilian Journal of Microbiology

Escherichia coli shigatoxigénico (STEC) y E. coli enteropatógeno (EPEC) constituyen patovares de ... more Escherichia coli shigatoxigénico (STEC) y E. coli enteropatógeno (EPEC) constituyen patovares de E. coli que pueden causar diarrea infantil potencialmente mortal. Los objetivos del presente trabajo fueron: i) estudiar la persistencia de cepas STEC y EPEC en una matriz de arena sometida a condiciones ambientales estresantes (sequedad); ii) detectar la presencia de STEC y EPEC en areneros de jardines de infantes.Trabajo publicado en Cagliada, Maria del Pilar Lilia y Galosi, Cecilia Mónica (comps.). I Congreso de Microbiología Veterinaria. Libro de resúmenes. La Plata: Facultad de Ciencias Veterinarias, 2021.Facultad de Ciencias Veterinaria

Comunicación científica en formato E- PÓSTER, realizada en las III Jornadas Internacionales de In... more Comunicación científica en formato E- PÓSTER, realizada en las III Jornadas Internacionales de Investigación, Ciencia y Universidad y las XII Jornadas de Investigación UMaza, en el Bloque de comunicaciones científicas: "MEDICINA VETERINARIA EN EL ÁMBITO PECUARIO Y SALÚD PÚBLICA", el mismo fue moderado por el DR. BOTTINI RUBÉN. Las jornadas se llevaron adelante desde 19 al 23 de octubre del 2020 en formato totalmente virtual bajo plataforma Zoom y fueron transmitidas por el canal YouTube de la UMaza y el Facebook del Área de Ciencia y Técnica UMaza (Somos Ciencia y Técnica UMaza)

Emerging types of Shiga toxin-producing E. coli (STEC)

Escherichia coli shigatoxigenica (STEC) es un patogeno endemico en Argentina, responsable de diar... more Escherichia coli shigatoxigenica (STEC) es un patogeno endemico en Argentina, responsable de diarrea aguda sanguinolenta (DAS) y/o sindrome uremico hemolitico (SUH). La correlacion entre SUH y alimentos contaminados ha sido documentada, aunque no siempre se establecio la fuente de infeccion. La ruta de contagio persona-persona es relevante. Dados los registros previos de prevalencia de STEC en animales de compania y los habitos de convivencia humano-animal en centros urbanos, es necesario evaluar la ruta mascota-persona. A su vez, los roedores podrian tener un papel epidemiologico en la endemia. OBJETIVO: Estudiar posibles reservorios animales relacionados con casos de SUH/DAS en la Ciudad Autonoma de Buenos Aires y estimar la prevalencia de STEC en roedores. ME-TODOS: Se intervino en 28 casos de SUH y 49 de DAS. Se realizo rastrillaje de cepas STEC por PCR a partir de hisopados rectales de los animales vinculados a cada caso. La prevalencia en roedores se estimo por PCR de sus hiso...

InVet, 2013

Escherichia coli is a marker of fecal contamination in food. Within the specie there are health r... more Escherichia coli is a marker of fecal contamination in food. Within the specie there are health risk pathotypes. Among them, enteropathogenic E. coli and ent...

Microorganisms, 2021

Diarrheagenic Escherichia coli (DEC) pathovars impact childhood health. The southern region of Ar... more Diarrheagenic Escherichia coli (DEC) pathovars impact childhood health. The southern region of Argentina shows the highest incidence of hemolytic uremic syndrome (HUS) in children of the country. The big island of Tierra del Fuego (TDF) in Argentina registered an incidence of five cases/100,000 inhabitants of HUS in 2019. This work aimed to establish the prevalence of STEC, EPEC, and EAEC in lambs slaughtered in abattoirs from TDF as well as to characterize the phenotypes and the genotypes of the isolated pathogens. The prevalence was 26.6% for stx+, 5.7% for eae+, and 0.27% for aagR+/aaiC+. Twelve STEC isolates were obtained and belonged to the following serotypes: O70:HNT, O81:H21, O81:HNT, O102:H6, O128ab:H2, O174:H8, and O174:HNT. Their genotypic profiles were stx1c (2), stx1c/ehxA (3), stx2b/ehxA (1), stx1c/stx2b (2), and stx1c/stx2/ehxA (4). Six EPEC isolates were obtained and corresponded to five serotypes: O2:H40, O32:H8, O56:H6, O108:H21, and O177:H25. All the EPEC isolates...