Background: aaP, aggR, and astA have been found to play important roles in diarrheal pathogenecity of EAEC. They may be exist in other diarrheagenic E.coli (DEC). Objectives: To determine the distribution of aaP, aggR, and astA in ETEC, EPEC, EIEC and non-diarrheagenic E.coli. Subjects and method: 75 strains of ETEC, EPEC, EIEC and 100 non-DEC have been screen by PCR with primers specific toaaP, aggR, and astA. Results: aaP, aggR, and astA have been seen in DEC with the prevence from 7 to 72,7%. The highest prevence was in EIEC, 72,7% for aap; 45,5% in EIEC for aggR; and 50% in ETEC for astA. 14% of non-DEC harbored aggR and more than 30% harbored aap and astA. Conclusion: This finding has contributed to understanding the distribution of aap, aggR and astA in ETEC, EPEC, EIEC and non-DEC as well.
Enterotoxigenic Escherichia coli ; Enteropathogenic Escherichia coli ; Escherichia coli ;

Attaching and effacing Escherichia coli (AEEC) cause enteric infections in humans and animals. Attaching indicates the intimate attachment of bacteria to the enterocyte, and effacing relates to the localized effacement of brush border microvilli. Enteropathogenic (EPEC) and enterohemorrhagic Escherichia coli (EHEC) infections are characterized by the formation of attaching and effacing (AE) lesion on the intestinal epithelial cells. Therefore, they are often grouped together as AEEC. Development of multiplex PCR allowed us to type five of the most important genes implicated in the formation of the AE lesion. A total of 60 AEEC strains isolated from diarrheal patients were investigated by multiplex PCR for the presence of the insertion site of locus of enterocyte effacement (LEE) and LEE-related (eae, tir, espA, espB, and espD) genes. Associating the results of LEE genes typing in the AEEC strains, three different pathotypes are determined: eae(gamma)-tir(gamma)-espA(gamma)-espB(gamma)-espD(gamma) (O157:H7), eae(beta)-tir(beta)-espA(beta)-espB(beta)-espD(beta) (O26:H11), and eae(alpha)-tir(alpha)-espA(alpha)-espB(alpha)-espD(alpha) (O55:H6). These results indicate that AEEC are a heterogenous groups of organisms.
Animals ; Bacteria ; Enterocytes* ; Enterohemorrhagic Escherichia coli* ; Enteropathogenic Escherichia coli* ; Epithelial Cells ; Escherichia coli ; Humans ; Microvilli ; Multiplex Polymerase Chain Reaction

OBJECTIVETo investigate the molecular typing feature of enteropathogenic Escherichia coli (EPEC) strains isolated from different reservoirs in eight provinces of China from 2006 to 2014.

METHODSAccording to the time, place, reservoir, and PFGE pattern of the EPEC strains isolated from stools of humans with diarrhea, animal feces, and foods in eight provinces of China between 2006 and 2014, 149 EPEC strains were selected and characterized by multilocus sequence typing (MLST) using seven housekeeping genes provided by E.coli MLST database. Strain analysis demonstrated 56 different sequence types (STs). SeqMan II, MEGA 5.05, and eBURST V3 were applied to analyze the genetic relationships of domestic and forein existing 392 strains (243 EPEC strains included in the E.coli MLST database and 149 EPEC strains comprised in the present study).

RESULTSAmong the 56 different STs, the prevalent ST was ST-40, which included 19 (19/149, 12.8%) isolates. Nineteen new STs were identified. Eleven new alleles were detected in six house-keeping genes (adk, fumC, gyrB, icd, mdh, and purA). Six STs were simultaneously detected among EPEC strains isolated from patients with diarrhea and animals. And these EPEC strains were all aEPEC strains. Two STs were simultaneously identified among EPEC strains isolated from patients with diarrhea and foods. Also, these EPEC strains were all aEPEC strains. 33 out of 173 STs were divided into five major clone complexes by eBURST, STC-29, STC-10, STC-20, STC-28, and STC-517. The remaining EPEC strains included in the other 140 STs were part of the other clone complexes or just were singletons.

CONCLUSIONA high degree of phylogenetic heterogeneity was observed among the EPEC strains isolated in eight provinces of China. The EPEC strains with same STs of human isolates isolated from animal feces and foods were all aEPEC strains.

Animals ; China ; Diarrhea ; Enteropathogenic Escherichia coli ; Escherichia coli ; Escherichia coli Proteins ; Feces ; Humans ; Multilocus Sequence Typing ; Phylogeny

In infants, urinary tract infections (UTIs) are quite common and primarily caused by bacterial pathogens. However, little research has been conducted regarding the relationship between uropathogenic bacteria, virulent genes, and uropathogenic viruses that might induce UTIs in infants. In this study, we evaluated infants with UTIs to determine the influence of bacterial virulent genes and type of viral infections on clinical aspects. First, we detected 44 cases of bacterial UTI from 600 suspected cases in infants and children. We detected E. coli urovirulence genes (kps, usp, pap, ireA, and cnf), two enteropathogenic E. coli genes (bfpA, and eae) and four S. aureus and S. epidermidis genes (mecA, pvl, bbp, and icaA) in urine samples from infant UTI cases. We also simultaneously detected hematuria-related adenovirus type 11, 21, and BK virus (BKV) in urine samples by PCR. As a result, E. coli was the most prevalent bacteria and in Dimercaptosuccinic acid (DMSA)-positive UTI cases, the uropathogenic E. coli virulence factor pap was significantly high. We found that BKV detection was significantly higher in DMSA-positive UTI infants (89%) compared with 50% of non-UTI (no bacteria detected) cases. These results are indicative of combined multiple bacterial and viral infections and show severe infant pyelonephritis.
Adenoviridae ; Bacteria ; Benzophenones ; BK Virus ; Boronic Acids ; Child ; Enteropathogenic Escherichia coli ; Escherichia ; Escherichia coli ; Humans ; Infant ; Polymerase Chain Reaction ; Pyelonephritis ; Succimer ; Urinary Tract ; Urinary Tract Infections

BACKGROUND: We investigated the prevalence of various pathogens (13 enteric bacteria and 5 viruses) which cause diarrhea using multiplex PCR of stool specimens and compared two multiplex PCR methods for detecting diarrheagenic Escherichia coli. METHODS: A total of 405 stool specimens submitted between November 2010 to February 2011 for routine culture of enteric pathogens were included and screened for five viruses (astrovirus, Group A rotavirus, enteric adenovirus, norovirus G1/G2) and eight bacteria (Salmonella spp., Shigella spp., Campylobacter spp., Vibrio spp., C. difficile Toxin B, C. perfringens, Y. enterolytica, Aeromonas spp.) using the Seeplex(R) Diarrhea ACE detection kit (Seegene). In addition, virulence-associated genes of enteropathogenic E. coli, (EPEC), enterohemorrhagic E. coli (EHEC), enteroinvasive E. coli, (EIEC), enterotoxigenic E. coli (ETEC), and enteroaggressive E. coli (EAEC) were detected using 16-plex PCR and a commercial diarrheagenic E. coli detection (DEC) PCR kit (SSI Diagnostica). RESULTS: Overall, 138 (34.1%) of 405 samples was positive for pathogen. The positive rate for virus was 18.5%. norovirus G2, Group A rotavirus, enteric adenovirus, astrovirus and norovirus G1 were detected in 40, 23, 8, 3 and 1 samples, respectively. The positive rate for bacteria was 24.4% (99/405). C. difficile toxin B was the most frequently detected, followed by C. perfringens, EPEC, and EAEC. The agreements of the two multiplex PCR methods for detecting EPEC and EHEC were 99.3% and 100%, respectively. CONCLUSION: The detection rate was high (34.1%) including various diarrheagenic E. coli (6.2%) and C. perfringens (5.2%). Multiplex PCR is thus useful for detecting various pathogens.
Adenoviridae ; Aeromonas ; Bacteria ; Campylobacter ; Diarrhea ; Enterobacteriaceae ; Enterohemorrhagic Escherichia coli ; Enteropathogenic Escherichia coli ; Enterotoxigenic Escherichia coli ; Escherichia ; Escherichia coli ; Multiplex Polymerase Chain Reaction ; Norovirus ; Polymerase Chain Reaction ; Prevalence ; Rotavirus ; Shigella ; Vibrio ; Viruses

OBJECTIVETo understand the distribution of virulence gene and the epidemiological characteristics of diarrheagenic Escherichia(E.) coli (DEC) from diarrheal patients in Beijing.

METHODSStool specimens from diarrheal patients were cultured which were collected from the hospitals under sentinel surveillance program, during 2012-2013. DNA was examined by real-time PCR.

RESULTS253 out of 6 370 specimens were positive for DEC detection with the rate as 4.0%. A total number of 262 DEC strains were isolated. Two different pathotypes of DEC strains with mixed infection, were isolated from 9 specimens. Different pathotypes would show the following profiles: 42.8% for enteropathogenic E. coli (EPEC) including 42.0% atypical and 0.8% typical; 38.9% for enterotoxigenic E. coli (ETEC) including 24.8% st positive, 9.9% lt positive and 4.2% st and lt both positive;15.3% for enteroaggregative E. coli(EAEC);2.7% for enteroinvasive E. coli (EIEC); one strain STEC with serotype O26:K60. ETEC had obvious characteristics on age. All kinds of DEC were isolated throughout the year with seasonal fluctuation.

CONCLUSIONDEC isolates from diarrheal patients in Beijing were dominated by EPEC and ETEC, with atypical ones accounted for the majority of EPEC. One specimen was found under mixed infection. Pathotypes DEC were found to have different age and seasonal distributions.

China ; epidemiology ; Diarrhea ; microbiology ; Enteropathogenic Escherichia coli ; genetics ; isolation & purification ; Enterotoxigenic Escherichia coli ; genetics ; isolation & purification ; Epidemics ; Escherichia coli ; genetics ; isolation & purification ; Escherichia coli Infections ; epidemiology ; microbiology ; Genotype ; Humans ; Virulence

OBJECTIVE: The study aimed to determine the basic histomorphologic effects of Bacillus clausii (B. clausii) spores in enteropathogenic Escherichia coli (E. coli) O127:H21-infected mice by evaluating the spleen, mesenteric lymph nodes, and intestinal mucosa.

METHODS: The study involved 46 apparently healthy Balb/c mice (Mus musculus) which were acclimatized for 19 days prior to any intervention. Sixteen mice were used to determine the sublethal dose of E. coli, which was performed by administering serially-diluted solutions and subsequent generation of a standard curve. From the remaining 30 mice, ten served as normal controls while the remaining 20 were randomized to receive either B. clausii or placebo of sterile water for a week. All mice were then challenged with E. coli for another week and euthanized, and the spleen, mesenteric lymph nodes, and small intestine harvested and examined microscopically. All study personnel were blinded of the treatment assignments.

RESULTS: Histologic evaluation of the small intestine in E. coli only-fed mice exhibited prominent attachment effacement lesions, with severely denuded mucosa, lymphocytic infiltration, and debris in the intestinal lumen. However, mice given B. clausii prior to E. coli infection displayed only minimal mucosal damage with less sloughing of villus tips, plus increased mucus-secreting goblet cells. In the spleen, E. coli only-fed mice showed moderate to severe lymphoid hyperplasia with blurred boundaries between red and white pulp. In contrast, mice which received B. clausii prior to E. coli infection had only mild degrees of lymphoid hyperplasia. Similar findings were seen in the mesenteric lymph nodes where E. coli only-fed mice showed moderate to severe lymphoid hyperplasia while those given B. clausii prior to E. coli infection merely had mild lymphoid hyperplasia.

CONCLUSION: B. clausii exerts a potential protective and immunomodulatory action in E. coli O127:H21-infected mice based on histomorphologic effects. However, additional studies are needed to fully characterize these mechanisms.mice based on histomorphologic effects. 

Animal ; Enteropathogenic Escherichia Coli ; Goblet Cells ; Mice, Inbred Balb C ; Spleen ; Bacillus Clausii ; Hyperplasia ; Escherichia Coli Infections ; Intestinal Mucosa ; Lymph Nodes

Enteropathogenic Escherichia coli (EPEC) have been implicated in human diarrhea in several countries. Central to EPEC-mediated disease is its ability to cause intestinal lesions, known as attaching and effacing (A/E) lesion. We investigated 92 EPEC strains isolated from patients with diarrhea in Gwangju for their genotypic and phenotypic characteristics. Sixteen (17.4%) of all strains were found to be typical EPEC because they were bfpA gene positive by PCR. The most of typical EPEC isolates (87.5%) showed a localized adhesion (LA) pattern in Hep-2 cell adherence assay, whereas, only 11 atypical EPEC isolates (14.5%) were adhered to Hep-2 cells in a localized manner. Thirteen of the EPEC strains studied belonged to classical O-serogroups of EPEC and 7 isolates were classified as nonclassical EPEC serogroup and the other isolates could not be serotyped with our antisera. The subtypes of eae, tir, espA and espB genes which are major virulence genes concerned of A/E lesion on chromosome were analyzed by multiplex PCR for finding the original resource. The results showed that the composition of these genes subtypes was homogenous and heterogenous in 12 and 26 isolates, respectively. The others were non-determined type in terms of the gene subtype because of genetic diversity of intimin-coding eae genes. Our findings indicated that EPEC isolates from patients with diarrhea were diverse genetically and phenotypically, which require further study in regard to their virulence and epidemiological significance.
Diarrhea ; Enteropathogenic Escherichia coli* ; Genetic Variation ; Gwangju* ; Humans ; Immune Sera ; Multiplex Polymerase Chain Reaction ; Polymerase Chain Reaction ; Virulence

Enteropathogenic Escherichia coli (EPEC) strains possess genes for attaching and effacing (eae) and EPEC adherence factor (EAF) plasmid. It is necessary to develop molecular techniques for the evaluation of EPEC isolates. A total of 183 E. coli isolates from neonates admitted to Pusan National University Hospital were investigated by polymerase chain reaction (PCR) and DNA colony hybridization. Of the 183 isolates tested, 10 (5.5%) were positive for eae by PCR and DNA colony hybridization and confirmed to be EPEC. Ten EPEC isolates showed 3 different adherence patterns: seven strains had diffuse adherence, two localized adherence-like adherence, and one aggregative adherence. They were also examined by antimicrobial susceptibility tests, serotyping, and molecular epidemiological typing such as pulsed field gel electrophoresis (PFGE) and random amplified polymorphic DNA (RAPD) analysis. The EPEC isolates could be divided into 9 different antimicrobial resistance patterns, 6 serotypes, 4 PFGE patterns, and 5 RAPD patterns. This result indicates that the EPEC isolates from neonates were originated from different sources.
Busan ; DNA ; Electrophoresis, Gel, Pulsed-Field ; Enteropathogenic Escherichia coli* ; HeLa Cells* ; Humans ; Infant, Newborn* ; Plasmids ; Polymerase Chain Reaction ; Serotyping

A hemagglutination(HA)-typing system has been developed for the presumptive identification of enterotoxigenic Escherichia coli(ETEC) possessing the colonization factor antigens(CFA) Seventy-seven E. coli strains from pediatric patients with or without diarrhea were examined for the mannose-resistant(MR) HA or mannose-sensitive(MS) HA of human, bovine, chicken, and guinea pig erythrocytes and their antibiotic resestances. A significant proportion(68%) of the isolates exhibited the HA pattern of NNNN(experssed in the order human/bovin/chicken/guinea pig erythrocytes), and 10% of the isolates exhibited NNSS, known as the pattern about half of enteropathogenic E. coli serogroups produced. Sixty-nine strains(88%) were resistant to one or more antibiotics; 55(80%) were reristant to four or more antibiotics. The strains showed multiple drug resistance were more higher in HA-positive strains(92% of HA-positive strains) than in HA-negative strains(76% of HA-negative strains) and all of the HA-positive strains with human erythrocytes were resistant to 4 or more antibiotics. There were no significant differences between HA patterns and antibiotic resistance in both the strains from the patients with or without diarrhea. In summary, although the causative organisms in cases of diarrhea of this study have not been established, the date herein suggested that ETEC possessing CFA which produce RRRN or NRRN HA pattern was not participated in this diarrhea.
Animals ; Anti-Bacterial Agents ; Chickens ; Child* ; Colon ; Diarrhea ; Drug Resistance* ; Drug Resistance, Microbial ; Drug Resistance, Multiple ; Enteropathogenic Escherichia coli ; Enterotoxigenic Escherichia coli ; Erythrocytes ; Escherichia coli* ; Escherichia* ; Guinea Pigs ; Hemagglutination* ; Humans