Presence and antibiotic resistance of diarrheagenic Escherichia coli in ready-to-eat salads / Монголын Анагаах Ухаан

Introduction@#Foodborne diseases are a major public health concern worldwide. The report, which estimates the burden of foodborne diseases – states that each year as many as 600 million, or almost 1 in 10 people in the world, fall ill after consuming contaminated food. Of these, 420 000 people die, including 125 000 children under the age of 5 years. The 20.3% of diarrhea and 27.5% of die caused by contaminated foods are diarrheagenic Escherichia coli (DEC).@*Aim@#To identify of DEC and determine their antibiotic resistance from ready-to-eat salads@*Material and Methods@#A total of 40 bagged salad mix samples were collected from food markets in Ulaanbaatar, Mongolia. Escherichia coli (E.coli) strains were determined on the basis of MNS 6308:2012 standard and confirmed by polymerase chain reaction (PCR) in samples. DEC was identified using multiplex PCR. Bacterial susceptibility to antimicrobial agents determined by the Kirby Bauer disk diffusion method.@*Results@#Our results showed the presence of E. coli in 19 samples (47.5%). DEC isolates identified by multiplex PCR were defined as follows: the presence of eae and bfp for EPEC, the presence of lt for ETEC, the presence of ipaH for EIEC, the presence of stx1 and stx2 for EHEC, the presence of aap and aggR for EAEC, and the presence of daaE for DAEC. The multiplex PCR assays detected EHEC 6 (31.6%), EPEC 5 (26.3%), EIEC 1 (5.3%). EAEC and ETEC were not detected in samples. The E.coli isolates were 73.7% resistant to chloramphenicol as the first choice of treatment of diarrhea and high resistance (68.4-94.7%) to the cephalosporins. In our country, cephalosporins are widely used in medical practice for the treatment of infectious diseases.@*Conclusion@#In this study, about half of ready-to-eat salads are contaminated with E. coli. The three types (EHEC, EPEC, EIEC) of DEC pathotypes were identified in the ready-to-eat salads and high prevalent of antimicrobial resistance. Future research is required to track the contamination sources and develop appropriate steps that should be taken by industry and retailers to reduce microbial contamination in ready-to-eat salads.

A case-control study on diarrheagenic E .coli infection in children / 中华传染病杂志

Objective To understand the regional epidemiology and antibiotic resistance pattern of diarrheagenic E .coli infection in children ,and to clarify the pathogenic association between diarrheagenic E .coli infection and childhood diarrhea .Methods Totally 680 diarrheal children in the outpatient setting and 680 non-diarrheal control children were enrolled prospectively .The stool samples were collected and the potential enteric pathogens were detected .Minimal inhibitory concentration (MIC) method was used to determine the antimicrobial susceptibility for diarrheagenic E .coli isolates .Results The isolation rates of diarrheagenic E .coli in diarrhea group and control group were 15 .6％ and 13 .1％ ,respecitvely ,and diarrheagenic E .coli was the most commonly detected enteric bacteria .Multivariate logistic regression analysis adjusted for age suggested no clinical association between diarrhea and infection with enteropathogenic E .coli (EPEC) (aOR=1 .2 ,95％ CI:0 .8-1 .8) ,enteroadhesive E .coli (EAEC) (aOR=1 .1 ,95％ CI:0 .7 -1 .6) and enterotoxigenic E .coli (ETEC) (aOR= 1 .8 ,95％ CI:0 .5 -6 .2) . Among 199 diarrheagenic E .coli strains ,the rates of resistance to ampicillin ,tetracycline ,trimethoprim-sulfamethoxazole ,azithromycin ,and ceftriaxone were 63 .8％ ,55 .8％ ,48 .2％ ,34 .2％ and 26 .6％ , respectively ,while the rates of resistance to ciprofloxacin , amoxicillin-clavulanate and cefoxitin were 4 .5％ ,1 .5％ and 0 .5％ ,respectively .Conclusions Diarrheagenic E .coli is the most common enteric bacteria detected in the stool samples from children with and without diarrhea in this study . The pathogenic role of infections with EPEC ,EAEC and ETEC in childhood diarrhea is not determined .EHEC and EIEC are rarely detected and further studies are needed to clarify the pathogenic association between infection with EHEC ,EIEC and childhood diarrhea .

Captive wild birds as reservoirs of enteropathogenic E. coli (EPEC) and Shiga-toxin producing E. coli (STEC)

ABSTRACT Psittacine birds have been identified as reservoirs of diarrheagenic Escherichia coli, a subset of pathogens associated with mortality of children in tropical countries. The role of other orders of birds as source of infection is unclear. The aim of this study was to perform the molecular diagnosis of infection with diarrheagenic E. coli in 10 different orders of captive wild birds in the state of São Paulo, Brazil. Fecal samples were analyzed from 516 birds belonging to 10 orders: Accipitriformes, Anseriformes, Columbiformes, Falconiformes, Galliformes, Passeriformes, Pelecaniformes, Piciformes, Psittaciformes and Strigiformes. After isolation, 401 E. coli strains were subjected to multiplex PCR system with amplification of genes eae and bfp (EPEC), stx1 and stx2 for STEC. The results of these tests revealed 23/401 (5.74%) positive strains for eae gene, 16/401 positive strains for the bfp gene (3.99%) and 3/401 positive for stx2 gene (0.75%) distributed among the orders of Psittaciformes, Strigiformes and Columbiformes. None of strains were positive for stx1 gene. These data reveal the infection by STEC, typical and atypical EPEC in captive birds. The frequency of these pathotypes is low and restricted to few orders, but the data suggest the potential public health risk that these birds represent as reservoirs of diarrheagenic E. coli.

Comparación entre el diagnóstico serológico y el diagnóstico por Reacción en Cadena de la Polimerasa (PCR) para Escherichia coli Enteropatogénica (EPEC) / Comparison of Enteropathogenic Escherichia Coli (EPEC) diagnosis by serology and by Polymerase Chain Reaction (PCR)

Introdución. En los laboratorios clínicos la identificación de EPEC se basa en la determinación de serotipos específicos por técnicas de aglutinación utilizando antisueros O y H. Actualmente la identificación del gen de intimina (eaeA) por PCR es el método diagnóstico de elección para EPEC. Objetivos. Comparar el diagnóstico por serología con el diagnóstico por PCR de cepasde EPEC. Materiales y Métodos. Se recolectaron cepas identificadas como EPEC en base al antígeno O, de 4 laboratorios clínicos de Lima, procedentes de muestras de diarrea de niños menores de 5 años. En estas cepas se buscaron genes relacionados a virulencia mediante un PCR múltiple a tiempo real para las E. coli diarreogénicas. Resultados. Se recolectaron 113 cepas; 82% de niños menores de 2 años. Únicamente15 cepas (13.3%) presentaron el gen de intimina con un diagnóstico confirmatorio de EPEC. Adicionalmente se encontraron 3 cepas enterotoxigénicas (ETEC), 3 productoras de shiga-toxina (STEC), 1 entero agregativa (EAEC) y 1 enteroinvasiva (EIEC). Conclusiones. Para la identificación correcta de EPEC se debe usar el PCR. Sin embargo, los métodos moleculares aún no están fácilmente disponibles en los laboratorios clínicos a nivel mundial.

Introduction. The identification of EPEC in clinical laboratories is based on the determination of the serotypes by agglutination with O and H antiserum. Currently the proper diagnosis of EPEC should be done by the identification of the intimin gen (eaeA) by PCR. Objectives. To compare the diagnosis of EPEC by serotypin and by PCR. Materials and Methods. We collected EPEC strains, identify by their O antigen, from 4 clinical laboratories in Lima from diarrheal samples in children less than 5 years of age. In those strains we have searched for virulence genes by a real time multiplex PCR for the diarrheagenic E. coli. Results: We collected 113 strains; 82% from children less than 2 years of age. Only 15 strains (13.3%) had the intimin gene and therefore a confirmatory diagnosis of EPEC. In addition we found 3 enterotoxigenic (ETEC), 3 shiga toxin-producing (STEC), 1 enteroagreggative (EAEC) and 1 enteroinvasive (EIEC) strains. Conclusions. PCR should be use for the proper identification of EPEC. However, molecular methods are still not easily available in clinical laboratories worldwide.

Distribution of serogroups of 162 diarrheagenic E.coli strains isolated from children under five in Ha Noi

E. coli is an emerging diarrheagenic pathogen. Serotyping is important to identify bacteria and trace their epidemiology. Objectives: (1) To identify the distribution of serogroup O among 4 kinds of diarrheagenic E. coli strains isolated from children with and without diarrhea in Hanoi, Vietnam. (2)To find out the relationship between serogroup O and different diarrheagenic E. coli. Method: One hundred and sixty-two strains of diarrheagenic E. coli including 86 EAEC, 50 EPEC, 12 EIEC, and 14 ETEC have been serotyped by slide agglutination with antisera specific for O serogroups. Results: More than 60% of the strains were serotyped. Serogroup O25 was the most common with the prevalence of 16.7% followed by O15 (4.3%). The other serogroups (O127a, O128, O126, O6, and O16) were seen in very few numbers. 38.3% of E. coli strains were not serotypeable with available antisera. EAEC were the most prevalent among diarrheagenic E. coli and 25.6% of them belong to the serogroup O25. Conclusion: 60% of the diarrheagenic E. coli strains were serotyped. Serogroup 025 was the most common. The findings were very useful for assessing the distribution of serogroups of diarrheagenic E. coli and will be useful for future vaccine development.