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Susceptibilidad antimicrobiana de aislamientos de Escherichia coli procedentes de ecosistemas dulceacuícolas Antimicrobial susceptibility of Escherichia coli isolates from river water ecosystems
Beatriz Romeu álvarez,Paloma Salazar Jiménez,Daysi Lugo Moya,Nidia M Rojas Hernández
Revista Cubana de Medicina Tropical , 2012,
Abstract: Introducción: la resistencia antimicrobiana constituye uno de los mayores problemas que afronta la salud pública mundial. La aparición de cepas resistentes no solo de origen clínico sino también ambiental agrava la situación. Entre los microorganismos que presentan esta característica se destaca la especie bacteriana Escherichia coli debido a su doble papel como indicador de contaminación fecal y como patógeno. Objetivos: aislar e identificar hasta especie aislamientos de Escherichia coli a partir de muestras de agua procedentes de ríos contaminados de La Habana y determinar la susceptibilidad antimicrobiana in vitro de estos aislados. Métodos: se estudiaron 113 aislamientos de bacterias coliformes aislados de 10 estaciones de muestreo ubicadas en la zona urbana de los ríos capitalinos Almendares, Quibú y Luyanó en el período comprendido de febrero de 2008 hasta junio de 2010. La identificación de los aislados, la determinación de la susceptibilidad antimicrobiana y la búsqueda de b-lactamasas de espectro extendido se realizó mediante el método automatizado VITEK. Resultados: se identificaron 113 cepas ambientales de Escherichia coli. Se demostró que 23 % de los aislamientos resultaron resistentes al menos a uno de los antimicrobianos evaluados. Los mayores porcentajes de resistencia se observaron frente a ampicilina, sulfametoxazol-trimetropin y ciprofloxacina. Conclusiones: la presencia de aislados de E. coli con multirresistencia antimicrobiana en estos ríos indica claramente el riesgo biológico que implica el uso de sus aguas. Introduction: antimicrobial resistance is one of the biggest problems facing global public health. The emergence of resistant clinical and environmental strains worsens the situation. Among the microorganisms with antimicrobial resistance, Escherichia coli species stands out due to its dual role as fecal contamination indicator and pathogen. Objectives: to isolate and identify Escherichia coli isolates from water samples from polluted rivers located in La Habana, and to determine their antimicrobial in vitro susceptibility. Methods: one hundred thirteen isolates of coliform bacteria isolated from 10 sampling stations in the capital′s urban areas near Almendares, Quibú and Luyanó rivers were studied in the period of February 2008 to June 2010. The identification of isolates, the determination of antimicrobial susceptibility and the search for extended-spectrum b-lactamase were all performed using VITEK automated method. Results: one hundred thirteen environmental strains of Escherichia coli were identified. It showed that 23 %
Phenotypical characterization and adhesin identification in Escherichia coli strains isolated from dogs with urinary tract infections
Maluta, Renato Pariz;Stella, Ariel Eurides;Riccardi, Kátia;Rigobelo, Everlon Cid;Marin, José Moacir;Carvalho, Marileda Bonafim;ávila, Fernando Antonio de;
Brazilian Journal of Microbiology , 2012, DOI: 10.1590/S1517-83822012000100045
Abstract: pathogenic strains of escherichia coli are the most common bacteria associated with urinary tract infections in both humans and companion animals. standard biochemical tests may be useful in demonstrating detailed phenotypical characteristics of these strains. thirteen strains of e. coli isolated from dogs with utis were submitted to biochemical tests, serotyping for o and h antigens and antimicrobial resistance testing. furthermore, the presence of papc, sfa, and afa genes was evaluated by pcr, and genetic relationships were established using enterobacterial repetitive intergenic consensus pcr (eric-pcr). the antimicrobial that showed the highest resistance rate among the isolates was nalidixic acid (76.9%), followed by cephalotin (69.2%), sulfamethoxazole + trimethoprim (61.5%), tetracycline (61.5%), streptomycin (53.8%), ciprofloxacin (53.8%), ampicillin (46.2%), gentamicin (30.8%) and chloramphenicol (23.1%). no isolate was resistant either to meropenem or nitrofurantoin. among the five clusters that were identified using eric-pcr, one cluster (a) had only one strain, which belonged to a serotype with zoonotic potential (o6:h31) and showed the genes papc+, sfa+, afa-. strains with the genes papc-, sfa+, afa- were found in two other clusters (c and d), whereas all strains in clusters b and e possessed papc-, sfa-, afa- genes. sucrose and raffinose phenotypic tests showed some ability in discriminating clusters a, b and c from clusters d and e.
Estudio de marcadores fenotípicos y de susceptibilidad antimicrobiana en cepas de Escherichia coli entéricas
águila,Adalberto; Bernedo,Robert; Llop,Alina; Ramírez,Margarita; Bravo,Laura; Fernandez,Anabel; Ledo,Yudith;
Revista Cubana de Medicina Tropical , 2007,
Abstract: forty strains of escherichia coli isolated from children under 5 years of age with acute diarreas, coming from different provinces of the country , were analyzed. four important phenotypical determinants were tested: sorbosa, sorbitol, enterohemolysin and 0157: h7 serology, in order to select those strains from enterohemorrhagic or shiga toxin-producing category. likewise, they were characterized by biotyping and antimicrobial susceptibility methods. the use of phenotypical tests showed six strains with presumptive characteristics, four of which were most likely to be shiga toxin-producing strains. in antimicrobial susceptibility test, the strains showed high resistance mainly to ampicillin and trimethrophin-sulfamethoxasole. another interesting finding were intermediate resistance and susceptibility values to augmentin, aztreonan and ceftriaxone. there were 12 antimicrobial resistance patterns of which 10 were multi-resistant.
Enteroaggregative Escherichia coli: An Emerging Enteric Food Borne Pathogen  [PDF]
P. Kaur,A. Chakraborti,A. Asea
Interdisciplinary Perspectives on Infectious Diseases , 2010, DOI: 10.1155/2010/254159
Abstract: Enteroaggregative Escherichia coli (EAEC) are quite heterogeneous category of an emerging enteric pathogen associated with cases of acute or persistent diarrhea worldwide in children and adults, and over the past decade has received increasing attention as a cause of watery diarrhea, which is often persistent. EAEC infection is an important cause of diarrhea in outbreak and non-outbreak settings in developing and developed countries. Recently, EAEC has been implicated in the development of irritable bowel syndrome, but this remains to be confirmed. EAEC is defined as a diarrheal pathogen based on its characteristic aggregative adherence (AA) to HEp-2 cells in culture and its biofilm formation on the intestinal mucosa with a “stacked-brick” adherence phenotype, which is related to the presence of a 60 MDa plasmid (pAA). At the molecular level, strains demonstrating the aggregative phenotype are quite heterogeneous; several virulence factors are detected by polymerase chain reaction; however, none exhibited 100% specificity. Although several studies have identified specific virulence factor(s) unique to EAEC, the mechanism by which EAEC exerts its pathogenesis is, thus, far unknown. The present review updates the current knowledge on the epidemiology, chronic complications, detection, virulence factors, and treatment of EAEC, an emerging enteric food borne pathogen. 1. Introduction Diarrheagenic Escherichia coli (E. coli) are the most common bacterial pathogens implicated in diarrhea worldwide. Diarrheagenic pathotypes recognized to date include enterotoxigenic E. coli (ETEC), which are characterized by producing heat-labile or heat-stable or both enterotoxins, enterohaemorrhagic E. coli (EHEC), which are characterized by attaching-and effacing-(A/E) lesions and shiga-like toxin or verotoxins, enteropathogenic E. coli (EPEC), which elicit characteristic attaching and effacing lesions on the intestinal mucosa, enteroinvasive E. coli (EIEC), which has the ability to invade epithelial cells similar to Shigella and is characterized by the presence of a large invasiveness plasmid, diffusely adherent E. coli (DAEC) demonstrates pattern of diffuse adherence, and enteroaggregative E. coli (EAEC), which demonstrate a characteristic “stacked-brick” aggregative adherence when cultured with HEp-2 cells [1, 2]. Other diarrheagenic E. coli pathotypes have been proposed, such as cell detaching E. coli (CDEC). However, their significance remains uncertain [3]. EAEC is the most recently identified diarrheagenic E. coli. EAEC is increasingly recognized as an emerging
Etiología bacteriana de la infección urinaria y susceptibilidad antimicrobiana en cepas de Escherichia coli
Díaz Rigau,Leonor; Cabrera Rodríguez,Luis Enrique; Fernández Nú?ez,Tania; González Febles,Ortelio; Carrasco Guzmán,Miguel; Bravo,Laura;
Revista Cubana de Pediatr?-a , 2006,
Abstract: la infección del tracto urinario constituye un problema de salud frecuente. se realizó un estudio descriptivo-retrospectivo con el objetivo de conocer el comportamiento y la frecuencia de los aislamientos bacterianos más frecuentes encontrados en muestras de orina de pacientes con diagnóstico presuntivo de infección urinaria. los pacientes tenían edades comprendidas entre 0 y 15 a?os y fueron hospitalizados en el hospital general docente ?aleida fernández chardiet?, en güines, entre el 2003 y el 2004. el mayor número de aislamientos correspondió a escherichia coli, klebsiella sp., proteus vulgaris, entre otros. las cepas de escherichia coli presentaron niveles de sensibilidad superiores al 90 % para los antibióticos ciprofloxacina, norfloxacina y amikacina, entre 85 % y 90 % para las 3 cefalosporinas en estudio y aminoglucósidos (gentamicina y kanamicina). el 64,2 % y 57,7 % de las cepas presentaron resistencia a la ampicilina y al trimetoprin-sulfametozaxol, respectivamente.
Etiología bacteriana de la infección urinaria y susceptibilidad antimicrobiana en cepas de Escherichia coli Bacterial etiology of urinary sepsis and antimicrobial susceptibility in strains from Escherichia coli
Leonor Díaz Rigau,Luis Enrique Cabrera Rodríguez,Tania Fernández Nú?ez,Ortelio González Febles
Revista Cubana de Pediatr?-a , 2006,
Abstract: La infección del tracto urinario constituye un problema de salud frecuente. Se realizó un estudio descriptivo-retrospectivo con el objetivo de conocer el comportamiento y la frecuencia de los aislamientos bacterianos más frecuentes encontrados en muestras de orina de pacientes con diagnóstico presuntivo de infección urinaria. Los pacientes tenían edades comprendidas entre 0 y 15 a os y fueron hospitalizados en el Hospital General Docente Aleida Fernández Chardiet , en Güines, entre el 2003 y el 2004. El mayor número de aislamientos correspondió a Escherichia coli, Klebsiella sp., Proteus vulgaris, entre otros. Las cepas de Escherichia coli presentaron niveles de sensibilidad superiores al 90 % para los antibióticos ciprofloxacina, norfloxacina y amikacina, entre 85 % y 90 % para las 3 cefalosporinas en estudio y aminoglucósidos (gentamicina y kanamicina). El 64,2 % y 57,7 % de las cepas presentaron resistencia a la ampicilina y al trimetoprin-sulfametozaxol, respectivamente.
Susceptibilidad antimicrobiana de aislamientos de Escherichia coli procedentes de ecosistemas dulceacuícolas
Romeu álvarez,Beatriz; Salazar Jiménez,Paloma; Lugo Moya,Daysi; Rojas Hernández,Nidia M; Eslava Campos,Carlos A;
Revista Cubana de Medicina Tropical , 2012,
Abstract: introduction: antimicrobial resistance is one of the biggest problems facing global public health. the emergence of resistant clinical and environmental strains worsens the situation. among the microorganisms with antimicrobial resistance, escherichia coli species stands out due to its dual role as fecal contamination indicator and pathogen. objectives: to isolate and identify escherichia coli isolates from water samples from polluted rivers located in la habana, and to determine their antimicrobial in vitro susceptibility. methods: one hundred thirteen isolates of coliform bacteria isolated from 10 sampling stations in the capital′s urban areas near almendares, quibú and luyanó rivers were studied in the period of february 2008 to june 2010. the identification of isolates, the determination of antimicrobial susceptibility and the search for extended-spectrum b-lactamase were all performed using vitek automated method. results: one hundred thirteen environmental strains of escherichia coli were identified. it showed that 23 % of the isolates were resistant to at least one of the tested antimicrobials. the highest percentages of resistance were observed to ampicilline, sulfamethoxazole-trimethoprim and ciprofloxacin. conclusions: the presence of e. coli isolates with multiple antimicrobial resistances in these rivers clearly indicates the biological risk involving the use of their waters.
Mathematical Model of Plasmid-Mediated Resistance to Ceftiofur in Commensal Enteric Escherichia coli of Cattle  [PDF]
Victoriya V. Volkova, Cristina Lanzas, Zhao Lu, Yrj? Tapio Gr?hn
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0036738
Abstract: Antimicrobial use in food animals may contribute to antimicrobial resistance in bacteria of animals and humans. Commensal bacteria of animal intestine may serve as a reservoir of resistance-genes. To understand the dynamics of plasmid-mediated resistance to cephalosporin ceftiofur in enteric commensals of cattle, we developed a deterministic mathematical model of the dynamics of ceftiofur-sensitive and resistant commensal enteric Escherichia coli (E. coli) in the absence of and during parenteral therapy with ceftiofur. The most common treatment scenarios including those using a sustained-release drug formulation were simulated; the model outputs were in agreement with the available experimental data. The model indicated that a low but stable fraction of resistant enteric E. coli could persist in the absence of immediate ceftiofur pressure, being sustained by horizontal and vertical transfers of plasmids carrying resistance-genes, and ingestion of resistant E. coli. During parenteral therapy with ceftiofur, resistant enteric E. coli expanded in absolute number and relative frequency. This expansion was most influenced by parameters of antimicrobial action of ceftiofur against E. coli. After treatment (>5 weeks from start of therapy) the fraction of ceftiofur-resistant cells among enteric E. coli, similar to that in the absence of treatment, was most influenced by the parameters of ecology of enteric E. coli, such as the frequency of transfer of plasmids carrying resistance-genes, the rate of replacement of enteric E. coli by ingested E. coli, and the frequency of ceftiofur resistance in the latter.
Experimental infection with enteropathogenic Escherichia coli identified by PCR using enteric-coated capsules in boxer pups
Gouveia, Eliana Maria Ferreira;Silva, Iandara Schettert;Nakazato, Gerson;Araujo, Flábio Ribeiro de;Chang, Marilene Rodrigues;
Acta Cirurgica Brasileira , 2011, DOI: 10.1590/S0102-86502011000200013
Abstract: purpose: to verify the possibility of an experimental infection with enteropathogenic escherichia coli and to confirm by pcr that the symptoms manifested after infection were due to the virulence factors of the studied bacteria. methods: experimental units were 14 healthy pups of boxer breed, aged 60 days. the animals were divided into three groups. one animal from each litter was included in a control group and the remaining animals were divided into two groups: one inoculated with strain 4083, and another one inoculated with strain spa14. gelatinous capsules coated with enteric-coating solution were used for the inoculation of strains. e. coli isolation from feces was performed for all tested animals, and the extracted dna was subjected to polymerase chain reaction (pcr). results: all infected animals presented diarrhea and had the gene eae amplified by pcr. conclusion: the efficiency of pcr for the studied strains indicates that this technique can be recommended for the diagnosis of enteropathogenic escherichia coli as a differential from other pathogens causing diarrhea. it may also be used in the future to verify whether other virulence factors (bfpa gene and eaf plasmid) persist after infection and to assess the pathogenicity of these bacteria.
Comparative Analysis of Virulence Factors of Escherichia coli from Non-enteric Infections
Md. Fakruddin,Reaz Mohammad Mazumdar,Abhijit Chowdhury,Khanjada Shahnewaj Bin Mannan
Journal of Medical Sciences , 2012,
Abstract: There is correlation between certain properties of E. coli strains and capacity of the strain to cause non-enteric infections. The aim of this study was to compare Escherichia coli strains isolated from non-enteric infection with those from faeces of normal healthy individuals, for their possession of haemolysin, mannose- resistant-haemagglutinin, colicin, protease, cell surface hydrophobicity and antibiotic susceptibility. Source wise distribution of the haemolytic strains were 60% from urine, 41.7% from blood, 33.3% from peritoneal fluid, 50% from pus and 26.7% from stool. Colicinogeny was found to be a common property of both clinical and faecal E. coli and only a few of the urine and blood isolates (52 and 41.7%, respectively) exhibited colicin V activity. Mannose Resistant Haemagglutinin (MRHA) test showed positive (MRHA+) reaction for 47.7% of the clinical E. coli isolates, while this value was only 26.7% for the controls. A significant association between haemolysin production and MRHA of human type O erythrocytes was found, as 75.86% of the Hly+ E. coli strains were also MRHA+. The data obtained in this study suggested that haemolysin production, MRHA of human type O erythrocytes and hydrophobic cell surface might be important for E. coli strains to initiate and sustain infection at non-enteric sites.
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