An Stx-EAEC O59:NM[H19] strain isolated from a hemolytic uremic syndrome case in Argentina / Cepa EAEC-Stx O59:NM[H19] aislada de un caso de síndrome urémico hemolítico en Argentina

Abstract Shiga toxin-producing Escherichia coli (STEC) are a heterogeneous group of foodborne pathogens causing a broad spectrum of human disease, from uncomplicated diarrhea to hemolytic uremic syndrome (HUS). In this study, we report an HUS case associated with an O59:NM H19 mstrain, harboring stx2a, iha, lpfAO26, lpfAO113 genes associated with STEC, and aatA, aap, pic, sigA, agg4A genes associated with enteroaggregative E. coli (EAEC), named Stx-EAEC. The strain showed low toxicity on Vero cells, and was resistant to streptomycin and trimethoprim/sulfonamides. The child carried the bacteria for more than 100 days. Since the large outbreak associated with Stx-EAEC O104:H4, many strains with similar profiles have been described. In Germany, an O59:NM[H19] strain, with comparable characteristics to the Argentine strain, was isolated from a bloody diarrhea case. In Argentina, this is the first report of an HUS case associated with a Stx-EAEC infection, and represents a new challenge for the surveillance system. © 2019 Published by Elsevier Espana, S.L.U. on behalf of Asociacion Argentina de Microbiolog´a. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/ licenses/by-nc-nd/4.0/).

Resumen Escherichia coli productor de la toxina Shiga (STEC) es un grupo heterogéneo de patógenos transmitidos por alimentos que causan un amplio espectro de enfermedades humanas, desde diarrea no complicada hasta síndrome urémico hemolítico (SUH). Nosotros informamos de un caso de SUH por O59:NM[H19], que portaba los genes stx2a, iha, lpfAo26, lpfAoii3 asociados con STEC, y los genes aatA, aap, pic, sigA, agg4A de E. coli enteroagregativo (EAEC), llamado EAEC-Stx. La cepa mostró baja citotoxicidad en las células Vero, y fue resistente a estreptomicina y trimetoprima/sulfonamidas. El niño excretó la bacteria durante más de 100 días. Desde el brote asociado con EAEC-Stx O104:H4, se describieron muchas cepas con perfiles similares. En Alemania se aisló una cepa O59:NM[H19] de una diarrea sanguinolenta, con características comparables a la cepa argentina. Este es el primer informe de un caso de SUH asociado a una infección por EAEC-Stx, y representa un nuevo desafío para el sistema de vigilancia. © 2019 Publicado por Elsevier Espana, S.L.U. en nombre de Asociación Argentina de Microbiología. Este es un artículo Open Access bajo la licencia CC BY-NC-ND (http://creativecommons. org/licenses/by-nc-nd/4.0/).

Identification of Enteroaggregative Escherichia coli in Mongolia / Монголын Анагаах Ухаан

Introduction: Enteroaggregative Escherichia coli (EAEC) is an important agent of acute and persistent diarrhea worldwide. Few cases have been reported in healthy children. EAEC strains are characterized by aggregative adherence (AA) to HEp-2 cells, wherein bacteria are seen in “stacked brick” aggregates attaching to HEp-2 cells and usually to the glass surface between cells. Goal: To identify Enteroaggregative Escherihia coli using multiplex polymerase chain reaction (PCR) and HEp-2 adherence assay in Ulaanbaatar, Mongolia Materials and Methods: A total of 329 E. coli strains were isolated from stool with diarrhea in National Center for Communicable Diseases from July 2012 through September 2014. All specimens were processed by routine microbiological and biochemical tests in the bacteriological laboratories to identify Salmonella spp., Shigella spp. All specimens in our study were negative for these bacterial and parasitic pathogens. The biofilm formation was evaluated by the growth rate of E.coli on plastic surface. PCR assays were used to detect genes of five types of diarrheagenic E.coli (DEC). All of the DEC strains showed mannose-resistant adherence to HEp-2 cells, and aggregative adherence was predominant in these isolates. Bacterial susceptibility to antimicrobial agents determined by the Kirby Bauer disk diffusion method on Muller Hinton agar. Results: EAEC (31.9%) was the most prevalent by PCR and HEp-2 assay comparing with others. EAEC by multiplex PCR in samples (11, 3.3%), followed by enteropathogenic E.coli (EPEC) seen in 2.1%. Enterohemorrhagic E.coli (EHEC) and enteroinvasive E.coli (EIEC) were found in 7 (2.1%) and 1 (0.3%) of the samples. Enterotoxigenic E.coli (ETEC) and diffusely adhering E.coli were detected in 2 (0.6%), respectively. The evaluation of bacterial biofilm formation using 96 well plates showed 309 negative (93%), 15 weak biofilm (4.6%) and 8 moderate biofilm (2.4%) formation for E.coli and no strong biofilm forming strain was detected. Above 50% of antibiotic resistance was observed for ampicillin, trimethoprim/sulfamethoxazole, cefuroxime and cephalotin. Also, 95.4% of isolates were resistant to at least three different classes of antimicrobial agents and considered as multidrug resistance. Conclusion: EAEC is most prevalent pathogen among DEC in our samples. It is necessary to implement EAEC identifying method on Hep-2 assay in our laboratory practice.

Epidemiological Relationship of Enterotoxigenic Escherichia coli and Enteroaggregative E. coli Isolated from Patients with Diarrhea in Seoul

Of total 1,438 specimens of patients with diarrhea in Seoul, 2011, 217 samples (15%) were found pathogenic Escherichia coli that included 192 strains (89%) of enterotoxigenic E. coli (ETEC) and enteroaggregative E. coli (EAEC). The highest isolation rate for ETEC and EAEC was found in August and September. Sixty two pathogenic E. coli strains (34 ETEC and 28 EAEC strains) were selected from 175 strains (94 ETEC and 81 EAEC strains) isolated in August and September. Of 94 strains characterized for ETEC phenotype, 76 (81%) expressed heat-stable toxin (ST) only. Antimicrobial susceptibility test was carried out by using sixteen types of antibiotics. A high level of antimicrobial resistance to tetracycline (57%), ampicillin and ticarcillin (54%) was observed among EAEC isolates while the highest resistance rate of ETEC was found for nalidixic acid (47%), followed by tetracycline (32%). As to the antimicrobial susceptibility test, EAEC showed the complicated multi-drug resistant patterns in which the resistance was higher than ETEC. Pulsed-field gel electrophoresis (PFGE) was carried out to examine the genetic relatedness among ETEC and EAEC isolates. Except for 11 strains, 51 strains were divided by eight pulsotypes. In PFGE analysis, isolates from foodborne disease outbreaks in August and September 2011 showed close relation.

Role of enteropathogenic escherichia coli in paediatric diarrhoeas in South India.

Background: Enteropathogenic Escherichia coli( EPEC) is a major cause of diarrhoea in children below 5 years of age. Serotyping is the classical method and PCR detection of virulence factors is a rapid way of detecting diarrhoeagenic Esch.coli. Objectives : To study the role of EPEC in Paediatric diarrhoea by both Serogrouping and Multiplex PCR assay and to analyse the antibiotic susceptibililty pattern of EPEC strains in our area. Materials and Methods : Prospective study of stool samples collected from children with diarrhoea and without diarrhoea who were below 5 years of age was conducted from May to November 2011. EPEC isolates were identified by Serogrouping. Escherichia coli isolates were subjected to Serogrouping and Multiplex PCR assay and those isolates which showed pathogenic genes were further serotyped. Antibiotic susceptibility pattern of EPEC isolates was determined by Clinical and Laboratory Standards Institute guidelines. Results : Among the Escherichia coli isolates in the diarrhoeal group, 36.8% were identified as EPEC by Serogrouping and 38.8% of them were found to possess EAEC genes by molecular characterisation. In the nondiarrhoeal Esch. coli strains , none agglutinated with EPEC polyvalent sera, 46.6% showed EAEC genes out of which 85.7% were of a single serotype O153. Among the Escherichia coli isolates which agglutinated with EPEC polyvalent antisera , 33.3% were positive for Enteroaggregative genes. Conclusion : EPEC is still an important pathogen in paediatric diarrhoeas . O serogrouping can still be relied upon for detection of EPEC. EAEC are present in classical ‘ O ‘ serogroups. Serotype O 153 has an increasing potential for asymptomatic carrier state in children below 5 years of age.

Detection of aap, aggR, and astA in strains off enteroaggregative E.Coli

Background: Aap, aggR, astA have been found to play important roles in diarrheal pathogenecity of enteroaggregative (EAEC). Objective: (1) To determine the distribution of aap, aggR, astA in EAEC. (2) To compare the distribution of aap, aggR, astA in EAEC isolated from healthy children and children with diarrhea. Subject and methods: \r\n', u'86 strains of EAEC isolated from children under 5 living in Hanoi, have been screened by PCR with specific primers. Results: Aap was found at the highest prevalence of 96.5%, aggR (79.1 %) and astA (60.5%). 37.2% of strains had all of aap, aggR and astA. None of strains was shown negative with these genes. Distributive rate of aap, aggR, astA in EAEC strains isolated from children with diarrhea was higher than EAEC strains isolated from healthy children. However, this difference was not statistically significant. Nearly 100% of the EAEC strains isolated from children with diarrhea had aap gene. The rate of aggR and astA was lower. Among children aged 0-24 months and children aged 25-60 months, distribution of these three genes was not different with statistical significance Conclusion: This finding has contributed to understanding the distribution of aap, aggR and astA of EAEC\r\n', u'\r\n', u'

Detection of common extended \ufffd?spectrum \xdf \ufffd?Lactamase genes in EAEC strains

Background:blaTEM, bla SHV, blaCTX \ufffd?M, blaOXA genes encode for extended spectrum \u03b2 \ufffd?lactamases resistance to broad \ufffd?spectrumcephalosporins. Many species belonging the family Enterobacteriaceae possess these genes. Objectives: To determine the distribution of blaTEM, bla SHV, blaCTX \ufffd?M and blaOXA genes in enteroaggregation E.coli (EAEC) strains. Subjects and method: 67 EAEC strains causing diarrhea and 18 strains isolated from healthy children were screened by PCR with primers specific to blaTEM, bla SHV, blaCTX \ufffd?M \ufffd?1and blaOXA genes. Results: The prevalence of ESBL genes in diarrheagenic EAEC strains and those isolated from healthy children were 83.6 and 72.2 %, respectively. The highest prevalence blaTEM gene (82% in diarrheagenic EAEC strains and 72.2% in isolated from healthy children) was followed by that of blaOXA gene (11.9 and 11.1% in two EAEC groups). Only 2 strains possess blaSHV gene. The blaCTX \ufffd?M \ufffd?1 was not detected in any EAEC strain. Conclusion: our findings have not only provided additional understanding of the distribution of blaTEM, bla SHV, blaCTX \ufffd?M - 1 and blaOXA genes in EAEC strains but also have a given significance in selecting antibiotics for treatment.