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Sharma B, Modgil V, Mahindroo J, Kumar A, Kaur V, Narayan C, Verma R, Mohan B, Taneja N. Are non-lactose-fermenting Escherichia coli important diarrhoeal pathogens in children and adults? Access Microbiol 2023; 5:acmi000459.v3. [PMID: 37601441 PMCID: PMC10436021 DOI: 10.1099/acmi.0.000459.v3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 01/02/2023] [Indexed: 08/22/2023] Open
Abstract
Introduction Diarrhoeagenic Escherichia coli (DEC) remains one of the major causes of acute diarrhoea episodes in developing countries. The percentage of acute diarrhoea cases caused by DEC is 30-40 % in these countries. Approximately 10% of E. coli isolates obtained from stool specimens have been reported to be non-lactose-fermenting (NLF). The available literature is sparse regarding the pathogenicity of NLF E. coli causing infectious diarrhoea. Aim We aimed to elucidate the importance of NLF E. coli in causing diarrhoea in both adults and children by detecting various DEC pathotypes among NLF E. coli in stool samples taken from gastroenteritis cases. Material and Methods A total of 376 NLF E. coli isolates from 3110 stool samples from diarrhoea/gastroenteritis patients were included in the study. Up to three NLF colonies that were not confirmed as Vibrio cholerae , Aeromonas spp., Salmonella spp. or Shigella spp., but were identified as E. coli using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF), were carefully picked up from each MacConkey agar plate and then meticulously streaked onto freshly prepared, sterilized nutrient agar plates, and biochemical reactions were conducted. Multiplex PCR was conducted for the EAEC, EPEC, ETEC and EHEC pathotypes and PCR for the ipaH gene was conducted for EIEC. The disc diffusion method was used for antibiotic sensitivity testing. Results Using multiplex PCR and ipaH PCR, a total of 63 pathotypes of DEC were obtained, with EAEC being the most predominant (n=31) followed by EIEC (n=22), EPEC (n=8) and ETEC (n=2). To further differentiate EIEC from Shigella , additional biochemical tests were performed, including acetate utilization, mucate and salicin fermentation, and aesculin hydrolysis. Antimicrobial susceptibility testing (AST) showed that maximum resistance was seen against ciprofloxacin (82.5 %) followed by ampicillin (77.8 %) and cotrimoxazole (68.2 %), and minimum resistance was seen against ertapenem (4.8 %). Conclusion In our study two pathotypes (EAEC, EIEC) were predominant among NLF E. coli and these were not only important aetiological agents in children, but also in adults. Our study also sheds light on the epidemiology of EIEC, which is one of the most neglected DEC pathotypes, as hardly any microbiological laboratories process NLF E. coli for EIEC.
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Affiliation(s)
- Bhawna Sharma
- Department of Microbiology, All India Institute of Medical Sciences, Bathinda, India
| | - Vinay Modgil
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Jaspreet Mahindroo
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Ajay Kumar
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Varpreet Kaur
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Chandradeo Narayan
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Ritu Verma
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Balvinder Mohan
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Neelam Taneja
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
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Ferreira AF, Braga RLL, Andrade MF, Rosa ACDP, Pereira-Manfro WF. SYNERGISTIC IMMUNOMODULATORY ACTIVITY OF PROBIOTICS BIFIDOBACTERIUM ANIMALIS AND LACTOBACILLUS CASEI IN ENTEROAGGREGATIVE ESCHERICHIA COLI (EAEC)-INFECTED CACO-2 CELLS. ARQUIVOS DE GASTROENTEROLOGIA 2021; 58:433-438. [PMID: 34909846 DOI: 10.1590/s0004-2803.202100000-79] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 05/03/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND Enteroaggregative Escherichia coli (EAEC) is an E. coli pathotype that presents aggregative adhesion patterns on in vitro cultivated cells, mainly related to persistent diarrhea cases in children. EAEC virulence factors are important for host colonization and pathogeni-city. Intestinal epithelial cells (IECs) recognize pathogen-associated molecular patterns (PAMPs) and initiate an immune response. Several studies using in vivo and in vitro models emphasize the probiotic activity and immunomodulatory capacity of Lactobacillus and Bifidobacterium species. OBJECTIVE To evaluate the modulation of cytokine production by probiotics Bifidobacterium animalis and Lactobacillus casei in human intestinal Caco-2 cells exposed to different strains of EAEC. METHODS Caco-2 cells were incubated with EAEC strains in the presence or absence of probiotics. The production of cytokines IL-8, TNF-α, IL-1β and IL-10 was evaluated in the supernatants by a sandwich enzyme-linked immunosorbent assay (ELISA). RESULTS Cytokine production did not change when uninfected and EAEC-infected Caco-2 cells were exposed to probiotics separately. All EAEC induced a significant increase in IL-8 production by Caco-2 cells, but the probiotics, even together, could not reduce its production. On the other hand, the synergic activity of probiotic strains significantly increased TNF-α production but decreased the basal production of IL-1ß. Also, probiotics induced a significant increase in the production of the anti-inflammatory cytokine IL-10 during EAEC infection. CONCLUSION Our results reinforce the synergistic immunomodulatory activity of probiotics during EAEC infection.
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Affiliation(s)
- Andréa Fonseca Ferreira
- Universidade do Estado do Rio de Janeiro, Faculdade de Ciências Médicas, Departamento de Microbiologia, Imunologia e Parasitologia, Rio de Janeiro, RJ, Brasil
| | - Ricardo Luís Lopes Braga
- Universidade do Estado do Rio de Janeiro, Faculdade de Ciências Médicas, Departamento de Microbiologia, Imunologia e Parasitologia, Rio de Janeiro, RJ, Brasil
| | - Maysa Ferreira Andrade
- Universidade do Estado do Rio de Janeiro, Faculdade de Ciências Médicas, Departamento de Microbiologia, Imunologia e Parasitologia, Rio de Janeiro, RJ, Brasil
| | - Ana Claudia de Paula Rosa
- Universidade do Estado do Rio de Janeiro, Faculdade de Ciências Médicas, Departamento de Microbiologia, Imunologia e Parasitologia, Rio de Janeiro, RJ, Brasil
| | - Wânia Ferraz Pereira-Manfro
- Universidade do Estado do Rio de Janeiro, Faculdade de Ciências Médicas, Departamento de Microbiologia, Imunologia e Parasitologia, Rio de Janeiro, RJ, Brasil
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Modgil V, Chaudhary P, Bharti B, Mahindroo J, Yousuf M, Koundal M, Mohan B, Taneja N. Prevalence, Virulence Gene Profiling, and Characterization of Enteroaggregative Escherichia coli from Children with Acute Diarrhea, Asymptomatic Nourished, and Malnourished Children Younger Than 5 Years of Age in India. J Pediatr 2021; 234:106-114.e5. [PMID: 33713662 DOI: 10.1016/j.jpeds.2021.03.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 03/04/2021] [Accepted: 03/05/2021] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To study the significance of enteroaggregative Escherichia coli (EAEC) as a pathogen causing acute diarrhea and a commensal in healthy nourished and malnourished children younger than five years of age in the Chandigarh region and to address possible traits of EAEC virulence genes, biofilm formation, phylogroups, and antibiotic resistance that would be correlated with diarrhea or carriage. STUDY DESIGN Stool samples were obtained from children with acute diarrhea (n = 548), as well as nourished (n = 550), and malnourished controls without diarrhea (n = 110). E coli isolates were confirmed as EAEC by pCVD432 polymerase chain reaction. Multiplex polymerase chain reactions were used to identify 22 virulence-related genes and phylogeny. Antibiotic susceptibility, adherence, and biofilm-forming potential also were studied. RESULTS Overall, 16.6% of children were malnourished. EAEC detection was greater among children with acute diarrhea (16%) than nourished (6%) and malnourished nondiarrheal controls (2.7%). We found an association of EAEC infections with age <2 years (P = .0001) in the diarrheal group. Adhesive variants adhesion fimbriae IV and adhesion fimbriae II were significantly associated with diarrhea. The aggR and aar genes showed a positive and negative association with the severity of disease (P = .0004 and P = .0003). A high degree of multidrug resistance was found (73.8%) in the diarrheal group. Most EAEC strains from the diarrheal group belonged to B2 and D phylogroups, whereas strains from non-diarrheal groups, which belonged to phylogroup B1. CONCLUSIONS EAEC is a significant contributor to childhood diarrhea, its presence as a commensal, and the significance of the association of various virulence factors among the EAEC isolated from diarrheal and non-diarrheal stools. These data reinforce the importance of aggR and aar as positive and negative regulators and the contribution of AAF/II and AAF/IV fimbria for the pathobiology of EAEC.
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Affiliation(s)
- Vinay Modgil
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Pankaj Chaudhary
- Department of Pediatrics Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Bhavneet Bharti
- Department of Pediatrics Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Jaspreet Mahindroo
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Md Yousuf
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Meenakshi Koundal
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Balvinder Mohan
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Neelam Taneja
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
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Molecular Epidemiology of Enteroaggregative Escherichia coli (EAEC) Isolates of Hospitalized Children from Bolivia Reveal High Heterogeneity and Multidrug-Resistance. Int J Mol Sci 2020; 21:ijms21249543. [PMID: 33334000 PMCID: PMC7765457 DOI: 10.3390/ijms21249543] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 12/10/2020] [Accepted: 12/12/2020] [Indexed: 12/16/2022] Open
Abstract
Enteroaggregative Escherichia coli (EAEC) is an emerging pathogen frequently associated with acute diarrhea in children and travelers to endemic regions. EAEC was found the most prevalent bacterial diarrheal pathogen from hospitalized Bolivian children less than five years of age with acute diarrhea from 2007 to 2010. Here, we further characterized the epidemiology of EAEC infection, virulence genes, and antimicrobial susceptibility of EAEC isolated from 414 diarrheal and 74 non-diarrheal cases. EAEC isolates were collected and subjected to a PCR-based virulence gene screening of seven virulence genes and a phenotypic resistance test to nine different antimicrobials. Our results showed that atypical EAEC (a-EAEC, AggR-negative) was significantly associated with diarrhea (OR, 1.62, 95% CI, 1.25 to 2.09, p < 0.001) in contrast to typical EAEC (t-EAEC, AggR-positive). EAEC infection was most prevalent among children between 7–12 months of age. The number of cases exhibited a biannual cycle with a major peak during the transition from warm to cold (April–June). Both typical and a-EAEC infections were graded as equally severe; however, t-EAEC harbored more virulence genes. aap, irp2 and pic were the most prevalent genes. Surprisingly, we detected 60% and 52.6% of multidrug resistance (MDR) EAEC among diarrheal and non-diarrheal cases. Resistance to ampicillin, sulfonamides, and tetracyclines was most common, being the corresponding antibiotics, the ones that are frequently used in Bolivia. Our work is the first study that provides comprehensive information on the high heterogenicity of virulence genes in t-EAEC and a- EAEC and the large prevalence of MDR EAEC in Bolivia.
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Modgil V, Mahindroo J, Narayan C, Kalia M, Yousuf M, Shahi V, Koundal M, Chaudhary P, Jain R, Sandha KS, Tanwar S, Gupta P, Thakur K, Singh D, Gautam N, Kakkar M, Bharti B, Mohan B, Taneja N. Comparative analysis of virulence determinants, phylogroups, and antibiotic susceptibility patterns of typical versus atypical Enteroaggregative E. coli in India. PLoS Negl Trop Dis 2020; 14:e0008769. [PMID: 33206643 PMCID: PMC7673547 DOI: 10.1371/journal.pntd.0008769] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 09/01/2020] [Indexed: 11/30/2022] Open
Abstract
Enteroaggregative Escherichia coli (EAEC) is an evolving enteric pathogen that causes acute and chronic diarrhea in developed and industrialized nations in children. EAEC epidemiology and the importance of atypical EAEC (aEAEC) isolation in childhood diarrhea are not well documented in the Indian setting. A comparative analysis was undertaken to evaluate virulence, phylogeny, and antibiotic sensitivity among typical tEAEC versus aEAEC. A total of 171 EAEC isolates were extracted from a broad surveillance sample of diarrheal (N = 1210) and healthy children (N = 550) across North India. Polymerase chain reaction (PCR) for the aggR gene (master regulator gene) was conducted to differentiate tEAEC and aEAEC. For 21 virulence genes, we used multiplex PCR to classify possible virulence factors among these strains. Phylogenetic classes were identified by a multiplex PCR for chuA, yjaA, and a cryptic DNA fragment, TspE4C2. Antibiotic susceptibility was conducted by the disc diffusion method as per CLSI guidelines. EAEC was associated with moderate to severe diarrhea in children. The prevalence of EAEC infection (11.4%) was higher than any other DEC group (p = 0.002). tEAEC occurrence in the diarrheal group was higher than in the control group (p = 0.0001). tEAEC strain harbored more virulence genes than aEAEC. astA, aap, and aggR genes were most frequently found in the EAEC from the diarrheal population. Within tEAEC, this gene combination was present in more than 50% of strains. Also, 75.8% of EAEC strains were multidrug-resistant (MDR). Phylogroup D (43.9%) and B1 (39.4%) were most prevalent in the diarrheal and control group, respectively. Genetic analysis revealed EAEC variability; the comparison of tEAEC and aEAEC allowed us to better understand the EAEC virulence repertoire. Further microbiological and epidemiological research is required to examine the pathogenicity of not only typical but also atypical EAEC. Enteroaggregative E. coli (EAEC) are an increasingly important cause of diarrhea. E. coli belonging to this category cause watery diarrhea, which is often persistent and can be inflammatory. It is also associated with traveler’s diarrhea in children and adults in middle and high-income countries. EAEC are defined by their ability to adhere to epithelial cells in a characteristic stacked brick-like pattern. However, the identification of these pathogenic strains remains elusive because of its heterogeneous nature. Genes that could contribute to the pathogenicity of EAEC encode adhesions, toxins, and other factors. Due to the heterogeneity of EAEC strains and differing host immune responses, not all EAEC infections are symptomatic. A critical factor in both recognizing EAEC pathogenesis and defining typical EAEC (tEAEC) strains is AggR, a transcriptional control for many EAEC virulence genes. The central role of aggR in virulence confers a strong priority to understand its pathogenicity. To identify EAEC, the CVD432 probe has been used. The CVD432 is a DNA probe from pAA plasmid of EAEC, has been reported to be specific for the detection of EAEC. The lack of sensitivity comes from the genetic heterogeneity of the EAEC strains and the wide geographic dispersal of strains. In our study, we performed a large surveillance of EAEC from North India among the pediatric population. Samples were collected by the microbiology staff at the Postgraduate Institute of Medical Education and Research (PGIMER) and referral system labs in Chandigarh (Manimajra), Punjab (Ludhiana), Haryana (Panchkula and Ambala Cantt), Himachal Pradesh (Hamirpur, Shimla, and Tanda), and Uttarakhand (Rishikesh, Rudrapur, and Haridwar)]. PGIMER is the largest tertiary care hospital in North India and serves patients from across Punjab, Jammu and Kashmir, Himachal Pradesh and Haryana. EAEC infections were detected using molecular methods. In our finding, astA, aap, and aggR genes were most frequently found in the EAEC from the diarrheal population. Within tEAEC, this gene combination is present in more than 50% of strains and helps to differentiate tEAEC from aEAEC. Our collection of EAEC strains helps in finding an appropriate marker for the early detection of EAEC. Our signature sequence (astA, aap, and aggR) will be ideal as focus genes for EAEC identification, as well as tEAEC and aEAEC. The multidrug resistance (MDR) was observed in 75.8% of the EAEC strains. tEAEC exhibits resistance to a greater number of antibiotics with respect to aEAEC. The phylogenetic analysis revealed that EAEC phylogeny is diverse and dispersed in all the phylogroups.
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Affiliation(s)
- Vinay Modgil
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
| | - Jaspreet Mahindroo
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
| | - Chandradeo Narayan
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
| | - Manmohit Kalia
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
| | - Md Yousuf
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
| | - Varun Shahi
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
| | - Meenakshi Koundal
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
| | - Pankaj Chaudhary
- Department of Pediatrics Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh (PGIMER), India
| | - Ruby Jain
- Civil Hospital Manimajra, Chandigarh, India
| | | | | | - Pratima Gupta
- Department of Microbiology, All India Institute of Medical Sciences (AIIMS), Rishikesh, Uttarakhand, India
| | - Kamlesh Thakur
- Department of Microbiology, Dr. Rajendra Prasad Government Medical College Kangra (RPGMC), Himachal Pradesh, India
| | - Digvijay Singh
- Department of Microbiology, Indira Gandhi Medical college (IGMC), Shimla, Himachal Pradesh, India
| | - Neha Gautam
- Department of Microbiology, Indira Gandhi Medical college (IGMC), Shimla, Himachal Pradesh, India
| | | | - Bhavneet Bharti
- Department of Pediatrics Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh (PGIMER), India
| | - Balvinder Mohan
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
| | - Neelam Taneja
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
- * E-mail:
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Alvestegui A, Olivares-Morales M, Muñoz E, Smith R, Nataro JP, Ruiz-Perez F, Farfan MJ. TLR4 Participates in the Inflammatory Response Induced by the AAF/II Fimbriae From Enteroaggregative Escherichia coli on Intestinal Epithelial Cells. Front Cell Infect Microbiol 2019; 9:143. [PMID: 31131263 PMCID: PMC6509964 DOI: 10.3389/fcimb.2019.00143] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 04/17/2019] [Indexed: 12/21/2022] Open
Abstract
Enteroaggregative Escherichia coli (EAEC) infections are one of the most frequent causes of persistent diarrhea in children, immunocompromised patients and travelers worldwide. The most prominent colonization factors of EAEC are aggregative adherence fimbriae (AAF). EAEC prototypical strain 042 harbors the AAF/II fimbriae variant, which mediates adhesion to intestinal epithelial cells and participates in the induction of an inflammatory response against this pathogen. However, the mechanism and the cell receptors implicated in eliciting this response have not been fully characterized. Since previous reports have shown that TLR4 recognize fimbriae from different pathogens, we evaluated the role of this receptor in the response elicited against EAEC by intestinal cells. Using a mutual antagonist against TLR2 and TLR4 (OxPAPC), we observed that blocking of these receptors significantly reduces the secretion of the inflammatory marker IL-8 in response to EAEC and AAF/II fimbrial extract in HT-29 cells. Using a TLR4-specific antagonist (TAK-242), we observed that the secretion of this cytokine was significantly reduced in HT-29 cells infected with EAEC or incubated with AAF/II fimbrial extract. We evaluated the participation of AAF/II fimbriae in the TLR4-mediated secretion of 38 cytokines, chemokines, and growth factors involved in inflammation. A reduction in the secretion of IL-8, GRO, and IL-4 was observed. Our results suggest that TLR4 participates in the secretion of several inflammation biomarkers in response to AAF/II fimbriae.
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Affiliation(s)
- Alejandra Alvestegui
- Departamento de Pediatría, Facultad de Medicina, Centro de Estudios Moleculares, Hospital Dr. Luis Calvo Mackenna, Universidad de Chile, Santiago, Chile
| | - Mauricio Olivares-Morales
- Departamento de Pediatría, Facultad de Medicina, Centro de Estudios Moleculares, Hospital Dr. Luis Calvo Mackenna, Universidad de Chile, Santiago, Chile
| | - Ernesto Muñoz
- Departamento de Pediatría, Facultad de Medicina, Centro de Estudios Moleculares, Hospital Dr. Luis Calvo Mackenna, Universidad de Chile, Santiago, Chile
| | - Rachel Smith
- Department of Pediatrics, University of Virginia School of Medicine, Charlottesville, VA, United States
| | - James P Nataro
- Department of Pediatrics, University of Virginia School of Medicine, Charlottesville, VA, United States
| | - Fernando Ruiz-Perez
- Department of Pediatrics, University of Virginia School of Medicine, Charlottesville, VA, United States
| | - Mauricio J Farfan
- Departamento de Pediatría, Facultad de Medicina, Centro de Estudios Moleculares, Hospital Dr. Luis Calvo Mackenna, Universidad de Chile, Santiago, Chile
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Taborda RLM, Silva LAD, Orlandi PP, Batista FS, Rodrigues RS, Matos NB. CHARACTERIZATION OF ENTEROAGGREGATIVE ESCHERICHIA COLI AMONG DIARRHEAL CHILDRENIN WESTERN BRAZILIAN AMAZON. ARQUIVOS DE GASTROENTEROLOGIA 2019; 55:390-396. [PMID: 30785524 DOI: 10.1590/s0004-2803.201800000-84] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 10/12/2018] [Indexed: 12/31/2022]
Abstract
BACKGROUND Enteroaggregative Escherichia coli (EAEC) is one of the main acute and chronic diarrhea causes both in children and adults, mainly in developing countries. OBJECTIVE The aim of the present study is to characterize EAEC strains isolated from faecal samples and to identify genes potentially contributing to virulence, biofilm production and antimicrobial resistance in children admitted to a pediatric hospital in Porto Velho, Rondônia State. METHODS The total of 1,625 E. coli specimens were isolated from 591 children in the age group 6 years or younger who were hospitalized in Cosme and Damião Children Hospital in Porto Velho, between February 2010 and February 2012, with acute gastroenteritis. Colonies suggestive of E. coli were subjected to polymerase chain reaction testing in order to identify the virulence factors. The in vitro adhesion assays using HEp-2 adherence were tests. Biofilm detection through spectrophotometry and antimicrobial susceptibility tests were conducted in the disk diffusion method. RESULTS The mentioned study examined 591 stool samples from children with diarrhea. Diarrheogenic E. coli was found in 27.4% (162/591) of the children. EAEC was the diarreagenic E. coli most frequently associated with diarrhea 52.4% (85/162), which was followed by enteropathogenic E. coli 43.8% (71/162), enterotoxigenic E. coli 2.4% (4/162), and enterohemorrhagic E. coli 1.2% (2/162). The aggR gene was detected in 63.5% (54/85) of EAEC isolates; moreover, statistically significant correlation was observed among typical EAEC (aggR) and aatA (P<0.0001), irp2 (P=0.0357) and shf (P=0.0328). It was recorded that 69% (59/85) of the 85 analyzed EAEC strains were biofilm producers; 73% (43/59) of the biofilm producers carried the aggR gene versus 42.3% (11/26) of non-producers (P=0.0135). In addition, there was association between the aatA gene and biofilm production; 61% (36/59) of the samples presented producer strains, versus 19.2% (5/26) of non-producers (P<0.0004). Antibiotic sensitivity test evidenced that most EAEC were ampicillin 70.6% (60/85), sulfamethoxazole 60% (51/85), tetracycline 44.7% (38/85) and cefotaxime 22.4% (19/85) resistant. CONCLUSION As far as it is known, the present study is pioneer in Northern Brazil to investigate EAEC virulence factors and to show the antimicrobial susceptibility of EAEC strains isolated from children with diarrhea.
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Affiliation(s)
| | | | | | | | | | - Najla Benevides Matos
- Centro de Pesquisa em Medicina Tropical, Porto Velho, RO, Brasil.,Fundação Oswaldo Cruz, FIOCRUZ - Porto Velho, RO, Brasil
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Diarrhoeagenic Escherichia coli and Escherichia albertii in Brazil: pathotypes and serotypes over a 6-year period of surveillance. Epidemiol Infect 2018; 147:e10. [PMID: 30229714 PMCID: PMC6518528 DOI: 10.1017/s0950268818002595] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Diarrhoeagenic Escherichia coli (DEC) is a leading cause of infectious diarrhoea worldwide. In recent years, Escherichia albertii has also been implicated as a cause of human enteric diseases. This study describes the occurrence of E. coli pathotypes and serotypes associated with enteric illness and haemolytic uremic syndrome (HUS) isolated in Brazil from 2011 to 2016. Pathotypes isolated included enteropathogenic E. coli (EPEC), enteroaggregative E. coli (EAEC), enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC) and Shiga toxin-producing E. coli (STEC). PCR of stool enrichments for DEC pathotypes was employed, and E. albertii was also sought. O:H serotyping was performed on all DEC isolates. A total of 683 DEC and 10 E. albertii strains were isolated from 5047 clinical samples. The frequencies of DEC pathotypes were 52.6% (359/683) for EPEC, 32.5% for EAEC, 6.3% for ETEC, 4.4% for EIEC and 4.2% for STEC. DEC strains occurred in patients from 3 months to 96 years old, but EPEC, EAEC and STEC were most prevalent among children. Both typical and atypical isolates of EPEC and EAEC were recovered and presented great serotype heterogeneity. HUS cases were only associated with STEC serotype O157:H7. Two E. albertii isolates belonged to serogroup O113 and one had the stx2f gene. The higher prevalence of atypical EPEC in relation to EAEC in community-acquired diarrhoea in Brazil suggests a shift in the trend of DEC pathotypes circulation as previously EAEC predominated. This is the first report of E. albertii isolation from active surveillance. These results highlight the need of continuing DEC and E. albertii surveillance, as a mean to detect changes in the pattern of pathotypes and serotypes circulation and provide useful information for intervention and control strategies.
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Distribution of genes encoding virulence factors and multilocus variable-number tandem-repeat analysis (MLVA) of entero-aggregative Escherichia coli (EAEC) isolated in Iran from patients with diarrhoea. J Med Microbiol 2018; 67:1334-1339. [DOI: 10.1099/jmm.0.000786] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Braga RLL, Pereira ACM, Ferreira AF, Rosa ACDP, Pereira-Manfro WF. INTRACELLULAR PERSISTENCE OF ENTEROAGGREGATIVE ESCHERICHIA COLI INDUCES A PROINFLAMMATORY CYTOKINES SECRETION IN INTESTINAL EPITHELIAL T84 CELLS. ARQUIVOS DE GASTROENTEROLOGIA 2018; 55:133-137. [PMID: 30043861 DOI: 10.1590/s0004-2803.201800000-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 02/07/2018] [Indexed: 11/22/2022]
Abstract
BACKGROUND The competence of enteroaggregative Escherichia coli (EAEC) to adhere to the intestinal epithelium of the host is a key role to the colonization and disease development. The virulence genes are crucial for EAEC pathogenicity during adherence, internalization and persistence in the host. The overwhelming majority of antigen encounters in a host occurs on the intestine surface, which is considered a part of innate mucosal immunity. Intestinal epithelial cells (IECs) can be activated by microorganisms and induce an immune response. OBJECTIVE The present study investigated the interaction of invasive EAEC strains with T84 intestinal epithelial cell line in respect to bacterial invasiveness, persistence and cytokines production. METHODS We evaluated intracellular persistence of invasive EAEC strains (H92/3, I49/3 and the prototype 042) and production of cytokines by sandwich ELISA in T84 cells upon 24 hours of infection. RESULTS The survival rates of the prototype 042 was 0.5x103 CFU/mL while survival of I49/3 and H92/3 reached 3.2x103 CFU/mL and 1.4x103 CFU/mL, respectively. Infection with all EAEC strains tested induced significant amounts of IL-8, IL-6 and TNF-α compared to uninfected T84 cells. CONCLUSION These data showed that infection by invasive EAEC induce a proinflammatory immune response in intestinal epithelial T84 cells.
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Affiliation(s)
- Ricardo Luís Lopes Braga
- Universidade do Estado do Rio de Janeiro, Faculdade de Ciências Médicas, Departamento de Microbiologia, Imunologia e Parasitologia, Rio de Janeiro, RJ, Brasil
| | - Ana Claudia Machado Pereira
- Universidade do Estado do Rio de Janeiro, Faculdade de Ciências Médicas, Departamento de Microbiologia, Imunologia e Parasitologia, Rio de Janeiro, RJ, Brasil
| | - Andréa Fonseca Ferreira
- Universidade do Estado do Rio de Janeiro, Faculdade de Ciências Médicas, Departamento de Microbiologia, Imunologia e Parasitologia, Rio de Janeiro, RJ, Brasil
| | - Ana Cláudia de Paula Rosa
- Universidade do Estado do Rio de Janeiro, Faculdade de Ciências Médicas, Departamento de Microbiologia, Imunologia e Parasitologia, Rio de Janeiro, RJ, Brasil
| | - Wânia Ferraz Pereira-Manfro
- Universidade do Estado do Rio de Janeiro, Faculdade de Ciências Médicas, Departamento de Microbiologia, Imunologia e Parasitologia, Rio de Janeiro, RJ, Brasil
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11
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Diarrheagenic Escherichia coli and Acute Gastroenteritis in Children in Davidson County, Tennessee, United States: A Case-control Study. Pediatr Infect Dis J 2018; 37:543-548. [PMID: 29341983 PMCID: PMC5962020 DOI: 10.1097/inf.0000000000001908] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Diarrheagenic Escherichia coli (DEC) is an important cause of acute gastroenteritis in children; however, there is limited information available on the epidemiology, phylogenetics, serotyping and antibiotic susceptibility of DEC in children in the United States. The aim of this study was to determine the molecular epidemiology of DEC among children with and without acute gastroenteritis in Davidson County, Tennessee. METHODS This prospective, frequency matched, case-control study recruited subjects 15 days to 17 years of age and detected DEC with polymerase chain reaction from stool samples. Additional testing was done to define phylogenetics and antibiotics resistance. RESULTS Among 1267 participants, 857 cases and 410 controls, 5.5% were positive for at least one subtype of DEC. Enteroaggregative E. coli [n = 32 (45%)] was the most common subtype followed by enteropathogenic E. coli (EPEC) [n = 30 (43%)], Shiga toxin-producing E. coli [n = 4 (6%)] and diffusely adherent E. coli [n = 4 (6%)]. No significant difference in prevalence of DEC was found between cases (5%) and controls (7%) [odds ratio: 0.66 (95% confidence interval: 0.4-1.07)], and results were similar when data were stratified by subtypes and adjusted for age, sex, race and ethnicity. Substantial diversity was found among DEC isolates in terms of phylotypes and serotypes, and a large proportion was resistant to, at least, one antibiotic. CONCLUSIONS Enteroaggregative E. coli and enteropathogenic E. coli were frequently found in both cases and controls in this study population. DNA-based methods for detection of these subtypes need further investigation to help differentiate between pathogenic and colonizing strains.
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12
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Novel Segment- and Host-Specific Patterns of Enteroaggregative Escherichia coli Adherence to Human Intestinal Enteroids. mBio 2018; 9:mBio.02419-17. [PMID: 29463660 PMCID: PMC5821088 DOI: 10.1128/mbio.02419-17] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Enteroaggregative Escherichia coli (EAEC) is an important diarrheal pathogen and a cause of both acute and chronic diarrhea. It is a common cause of pediatric bacterial diarrhea in developing countries. Despite its discovery in 1987, the intestinal tropism of the pathogen remains unknown. Cell lines used to study EAEC adherence include the HEp-2, T-84, and Caco-2 lines, but they exhibit abnormal metabolism and large variations in gene expression. Animal models either do not faithfully manifest human clinical symptoms or are cumbersome and expensive. Using human intestinal enteroids derived from all four segments of the human intestine, we find that EAEC demonstrates aggregative adherence to duodenal and ileal enteroids, with donor-driven differences driving a sheet-like and layered pattern. This contrasts with the colon, where segment-specific tropisms yielded a mesh-like adherence pattern dominated by interconnecting filaments. Very little to no aggregative adherence to jejunal enteroids was observed, regardless of the strain or donor, in contrast to a strong duodenal association across all donors and strains. These unique patterns of intestinal segment- or donor-specific adherence, but not the overall numbers of associated bacteria, were dependent on the major subunit protein of aggregative adherence fimbriae II (AafA), implying that the morphology of adherent clusters and the overall intestinal cell association of EAEC occur by different mechanisms. Our results suggest that we must give serious consideration to inter- and intrapatient variations in what is arguably the first step in pathogenesis, that of adherence, when considering the clinical manifestation of these infections. EAEC is a leading cause of pediatric bacterial diarrhea and a common cause of diarrhea among travelers and immunocompromised individuals. Heterogeneity in EAEC strains and lack of a good model system are major roadblocks to the understanding of its pathogenesis. Utilizing human intestinal enteroids to study the adherence of EAEC, we demonstrate that unique patterns of adherence are largely driven by unidentified factors present in different intestinal segments and from different donors. These patterns are also dependent on aggregative adherence fimbriae II encoded by EAEC. These results imply that we must also consider the contribution of the host to understand the pathogenesis of EAEC-induced inflammation and diarrhea.
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13
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Ikumapayi UN, Boisen N, Hossain MJ, Betts M, Lamin M, Saha D, Kwambana-Adams B, Dione M, Adegbola RA, Roca A, Nataro JP, Antonio M. Identification of Subsets of Enteroaggregative Escherichia coli Associated with Diarrheal Disease among Under 5 Years of Age Children from Rural Gambia. Am J Trop Med Hyg 2017; 97:997-1004. [PMID: 28820687 PMCID: PMC5637583 DOI: 10.4269/ajtmh.16-0705] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Enteroaggregative Escherichia coli (EAEC) cause acute and persistent diarrhea, mostly in children worldwide. Outbreaks of diarrhea caused by EAEC have been described, including a large outbreak caused by a Shiga toxin expressing strain. This study investigated the association of EAEC virulence factors with diarrhea in children less than 5 years. We characterized 428 EAEC strains isolated from stool samples obtained from moderate-to-severe diarrhea cases (157) and healthy controls (217) children aged 0–59 months recruited over 3 years as part of the Global Enteric Multicenter Study (GEMS) in The Gambia. Four sets of multiplex polymerase chain reaction were applied to detect 21 EAEC-virulence genes from confirmed EAEC strains that target pCVD432 (aatA) and AAIC (aaiC). In addition, Kirby-Bauer disc diffusion antimicrobial susceptibility testing was performed on 88 EAEC strains following Clinical Laboratory Standard Institute guidelines. We observed that the plasmid-encoded enterotoxin [odds ratio (OR): 6.9, 95% confidence interval (CI): 2.06–29.20, P < 0.001], aggregative adherence fimbriae/I fimbriae (aggA) [OR: 2.2, 95% CI: 1.16–4.29, P = 0.008], and hexosyltransferase (capU) [OR: 1.9, 95% CI 1.02–3.51, P = 0.028] were associated with moderate-to-severe diarrhea among children < 12 months old but not in the older age strata (> 12 months). Our data suggest that some EAEC-virulent factors have age-specific associations with moderate-to-severe diarrhea in infants. Furthermore, our study showed that 85% and 72% of EAEC strains tested were resistant to sulphamethoxazole-trimethoprim and ampicillin, respectively. Sulphamethoxazole-trimethoprim and ampicillin are among the first-line antibiotics used for the treatment of diarrhea in The Gambia.
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Affiliation(s)
- Usman N Ikumapayi
- Disease Control and Elimination Theme, Medical Research Council Unit The Gambia, Banjul, The Gambia.,Vaccines and Immunity Theme, Medical Research Council Unit The Gambia, Banjul, The Gambia
| | - Nadia Boisen
- Department of Microbiological Surveillance and Research, Statens Serum Institut, Copenhagen, Denmark
| | - Mohammad J Hossain
- Disease Control and Elimination Theme, Medical Research Council Unit The Gambia, Banjul, The Gambia
| | - Modupeh Betts
- Vaccines and Immunity Theme, Medical Research Council Unit The Gambia, Banjul, The Gambia
| | - Modou Lamin
- Disease Control and Elimination Theme, Medical Research Council Unit The Gambia, Banjul, The Gambia
| | - Debasish Saha
- Vaccines and Immunity Theme, Medical Research Council Unit The Gambia, Banjul, The Gambia
| | - Brenda Kwambana-Adams
- Vaccines and Immunity Theme, Medical Research Council Unit The Gambia, Banjul, The Gambia
| | - Michel Dione
- Vaccines and Immunity Theme, Medical Research Council Unit The Gambia, Banjul, The Gambia
| | - Richard A Adegbola
- Vaccines and Immunity Theme, Medical Research Council Unit The Gambia, Banjul, The Gambia
| | - Anna Roca
- Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom.,Disease Control and Elimination Theme, Medical Research Council Unit The Gambia, Banjul, The Gambia
| | - James P Nataro
- Department of Pediatrics, University of Virginia School of Medicine, Charlottesville, Virginia.,Centre for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland
| | - Martin Antonio
- Microbiology and Infection Unit, Warwick Medical School, University of Warwick, Coventry, United Kingdom.,Vaccines and Immunity Theme, Medical Research Council Unit The Gambia, Banjul, The Gambia.,Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
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14
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Hebbelstrup Jensen B, Poulsen A, Hebbelstrup Rye Rasmussen S, Struve C, Engberg JH, Friis-Møller A, Boisen N, Jønsson R, Petersen RF, Petersen AM, Krogfelt KA. Genetic Virulence Profile of Enteroaggregative Escherichia coli Strains Isolated from Danish Children with Either Acute or Persistent Diarrhea. Front Cell Infect Microbiol 2017; 7:230. [PMID: 28611957 PMCID: PMC5447714 DOI: 10.3389/fcimb.2017.00230] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Accepted: 05/17/2017] [Indexed: 11/13/2022] Open
Abstract
Enteroaggregative Escherichia coli (EAEC) is frequently found in diarrheal stools worldwide. It has been associated with persistent diarrhea, weight loss, and failure to thrive in children living in developing countries. A number of important EAEC virulence genes are identified; however, their roles in acute and persistent diarrhea have not been previously investigated. The aim of this study was to identify specific EAEC virulence genes associated with duration and type of diarrhea in Danish children. We aimed to improve the current diagnostics of EAEC and enable targeting of strains with an expected severe disease course. Questionnaires answered by parents provided information regarding duration of diarrhea and presence of blood or mucus. A total of 295 EAEC strains were collected from children with acute (≤7 days) and persistent diarrhea (≥14 days) and were compared by using multiplex PCR targeting the genes sat, sepA, pic, sigA, pet, astA, aatA, aggR, aaiC, aap, agg3/4C, ORF3, aafA, aggA, agg3A, agg4A, and agg5A. Furthermore, the distribution of EAEC genes in strains collected from cases of bloody, mucoid, and watery diarrhea was investigated. The classification and regression tree analysis (CART) was applied to investigate the relationship between EAEC virulence genes and diarrheal duration and type. Persistent diarrhea was associated with strains lacking the pic gene (p = 0.002) and with the combination of the genes pic, sat, and absence of the aggA gene (p = 0.05). Prolonged diarrhea was associated with the combination of the genes aatA and astA (p = 0.03). Non-mucoid diarrhea was associated with strains lacking the aatA gene (p = 0.004). Acute diarrhea was associated with the genes aggR, aap, and aggA by individual odds ratios. Resistance toward gentamicin and ciprofloxacin was observed in 7.5 and 3% of strains, respectively. Multi-drug resistance was observed in 38% of strains. Genetic host factors have been associated with an increased risk of EAEC-associated disease. Therefore, we investigated a panel of risk factors in two groups of children—EAEC-positive and EAEC-negative—to identify additional factors predisposing to disease. The duration of breastfeeding was positively correlated with the likelihood of belonging to the EAEC-negative group of children.
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Affiliation(s)
| | - Anja Poulsen
- Department of Gastroenterology, Copenhagen University Hospital HvidovreCopenhagen, Denmark
| | | | - Carsten Struve
- Department of Bacteria, Parasites and Fungi, Statens Serum InstitutCopenhagen, Denmark
| | - Jørgen H Engberg
- Department of Clinical Microbiology, Slagelse HospitalSlagelse, Denmark
| | - Alice Friis-Møller
- Department of Clinical Microbiology, Copenhagen University Hospital HvidovreCopenhagen, Denmark
| | - Nadia Boisen
- Department of Bacteria, Parasites and Fungi, Statens Serum InstitutCopenhagen, Denmark
| | - Rie Jønsson
- Department of Bacteria, Parasites and Fungi, Statens Serum InstitutCopenhagen, Denmark
| | - Randi F Petersen
- Department of Bacteria, Parasites and Fungi, Statens Serum InstitutCopenhagen, Denmark
| | - Andreas M Petersen
- Department of Bacteria, Parasites and Fungi, Statens Serum InstitutCopenhagen, Denmark.,Department of Gastroenterology, Copenhagen University Hospital HvidovreCopenhagen, Denmark.,Department of Clinical Microbiology, Copenhagen University Hospital HvidovreCopenhagen, Denmark
| | - Karen A Krogfelt
- Department of Bacteria, Parasites and Fungi, Statens Serum InstitutCopenhagen, Denmark
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15
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Gupta D, Sharma M, Sarkar S, Thapa BR, Chakraborti A. Virulence determinants in enteroaggregative Escherichia coli from North India and their interaction in in vitro organ culture system. FEMS Microbiol Lett 2016; 363:fnw189. [PMID: 27493010 DOI: 10.1093/femsle/fnw189] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/02/2016] [Indexed: 11/13/2022] Open
Abstract
Enteroaggregative Escherichia coli (EAEC) is an important diarrhoeal pathogen causing diseases in multiple epidemiological and clinical settings. In developing countries like India, diarrhoeal diseases are one of the major killers among paediatric population and oddly, few studies are available from Indian paediatric population on the variability of EAEC virulence genes. In this study, we examined the distribution of plasmid and chromosomal-encoded virulence determinants in EAEC isolates, and analysed cytokines response generated against EAEC with specific aggregative adherence fimbriae (AAF) type in duodenal biopsies using in vitro organ culture (IVOC) mimicking in vivo conditions. Different virulence marker combinations among strains were reflected as a function of specific adhesins signifying EAEC heterogeneity. fis gene emerged as an important genetic marker apart from aggA and aap Further, EAEC infection in IVOC showed upregulation of IL-8, IL-1β, IL-6, TNF-α and TLR-5 expression. EAEC with AAFII induced significant TLR-5 and IL-8 response, conceivably owing to more pathogenicity markers. This study sheds light on the pattern of EAEC pathotypes prevalent in North Indian paediatric population and highlights the presence of unique virulence combinations in pathogenic strains. Thus, evident diversity in EAEC virulence and multifaceted bacteria-host crosstalk can provide useful insights for the strategic management of diarrhoeal diseases in India, where diarrhoeal outbreaks are more frequent.
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Affiliation(s)
- Deepika Gupta
- Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - Monica Sharma
- Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - Subendu Sarkar
- Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - B R Thapa
- Department of Gastroenterology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - Anuradha Chakraborti
- Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India
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16
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Durand D, Contreras CA, Mosquito S, Ruíz J, Cleary TG, Ochoa TJ. pic gene of enteroaggregative Escherichia coli and its association with diarrhea in Peruvian children. Pathog Dis 2016; 74:ftw054. [PMID: 27307104 DOI: 10.1093/femspd/ftw054] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/01/2016] [Indexed: 11/12/2022] Open
Abstract
Enteroaggregative Escherichia coli (EAEC) causes acute and persistent diarrhea among children, HIV-infected patients, and travelers to developing countries. We have searched for 18 genes-encoding virulence factors associated with aggregative adherence, dispersion, biofilm, toxins, serine protease autotransporters of Enterobacteriaceae (SPATEs) and siderophores, analyzed in 172 well-characterized EAEC strains (aggR(+)) isolated from stool samples of 97 children with diarrhea and 75 healthy controls from a passive surveillance diarrhea cohort study in Peru. Eighty-one different genetic profiles were identified, 37 were found only associated with diarrhea and 25 with control samples. The most frequent genetic profile was aggC(+)aatA(+)aap(+)shf(+)fyuA(+), present in 19 strains, including diarrhea and controls. The profile set1A(+)set1B(+)pic(+) was associated with diarrhea (P < 0.05). Of all genes evaluated, the most frequent were aatA (CVD 342) present in 159 strains (92.4%) and fyuA in 157 (91.3%). When EAEC strains were analyzed as a single pathogen (excluding co-infections), only pic was associated with diarrhea (P < 0.05) and with prolonged diarrhea (diarrhea ≥ 7 days) (P < 0.05). In summary, this is the first report on the prevalence of a large set of EAEC virulence genes and its association with diarrhea in Peruvian children. More studies are needed to elucidate the exact role of each virulence factor.
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Affiliation(s)
- David Durand
- Alexander von Humboldt Tropical Medicine Institute, Cayetano Heredia Peruvian University, 430 Honorio Delgado Avenue, Lima 31, Perú
| | - Carmen A Contreras
- Alexander von Humboldt Tropical Medicine Institute, Cayetano Heredia Peruvian University, 430 Honorio Delgado Avenue, Lima 31, Perú Department of Molecular Microbiology, Institute of Biotechnology, National Autonomous University of Mexico, Cuernavaca postal code 62210, México
| | - Susan Mosquito
- Alexander von Humboldt Tropical Medicine Institute, Cayetano Heredia Peruvian University, 430 Honorio Delgado Avenue, Lima 31, Perú
| | - Joaquim Ruíz
- ISGlobal, Barcelona Institute for Global Health, Barcelona Centre for International Health Research (CRESIB), Hospital Clinic of Barcelona, University of Barcelona, 08036 Barcelona, Spain
| | - Thomas G Cleary
- University of Texas Health Science Center at Houston, School of Public Health, Houston, TX 77030, USA
| | - Theresa J Ochoa
- Alexander von Humboldt Tropical Medicine Institute, Cayetano Heredia Peruvian University, 430 Honorio Delgado Avenue, Lima 31, Perú University of Texas Health Science Center at Houston, School of Public Health, Houston, TX 77030, USA
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17
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Bafandeh S, Haghi F, Zeighami H. Prevalence and virulence characteristics of enteroaggregative Escherichia coli in a case-control study among patients from Iran. J Med Microbiol 2015; 64:519-524. [PMID: 25813820 DOI: 10.1099/jmm.0.000055] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 03/10/2015] [Indexed: 11/18/2022] Open
Abstract
Enteroaggregative Escherichia coli (EAEC) is an important agent of diarrhoeal diseases worldwide. The role of EAEC virulence factors in the clinical outcome of infection is not completely defined. This case-control study investigated the prevalence of EAEC, its virulence genes and the antimicrobial resistance profile of adult patients with and without diarrhoea attending three different hospitals in Zanjan, Iran. A total of 550 individual stool specimens (350 from diarrhoeal patients and 200 from patients without diarrhoea) were collected. One hundred and forty-one EAEC isolates were identified by a HEp-2 cell assay and PCR. EAEC isolates were detected with slightly higher frequency in patients with (27.7%) than in patients without (22%) diarrhoea (P ≥ 0.05). The EAEC genes aggR, aap and pet were identified more frequently in case patients compared with controls (P ≤ 0.05). Many of the EAEC isolates from the diarrhoeal patients had two or more virulence genes compared with those without diarrhoea (P ≤ 0.05). EAEC isolates exhibited high-level resistance to amoxicillin (82.3%), co-amoxiclav (78%), aztreonam (73.8%), tetracycline (66.6%) and ceftazidime (63.8%). In addition, 53.2% of isolates were resistant to at least three different classes of antimicrobial agents and were considered to be multidrug resistant. These results indicate a high prevalence and heterogeneity of gene profiles of EAEC in diarrhoeal and control patients, and suggest that the presence of aggR, aap and pet, the number of genes present and the antimicrobial resistance profile may be markers for more-virulent EAEC isolates.
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Affiliation(s)
- Saeed Bafandeh
- Department of Microbiology, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Fakhri Haghi
- Department of Microbiology, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Habib Zeighami
- Department of Microbiology, Zanjan University of Medical Sciences, Zanjan, Iran
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18
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Epidemiology and clinical manifestations of enteroaggregative Escherichia coli. Clin Microbiol Rev 2015; 27:614-30. [PMID: 24982324 DOI: 10.1128/cmr.00112-13] [Citation(s) in RCA: 129] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enteroaggregative Escherichia coli (EAEC) represents a heterogeneous group of E. coli strains. The pathogenicity and clinical relevance of these bacteria are still controversial. In this review, we describe the clinical significance of EAEC regarding patterns of infection in humans, transmission, reservoirs, and symptoms. Manifestations associated with EAEC infection include watery diarrhea, mucoid diarrhea, low-grade fever, nausea, tenesmus, and borborygmi. In early studies, EAEC was considered to be an opportunistic pathogen associated with diarrhea in HIV patients and in malnourished children in developing countries. In recent studies, associations with traveler's diarrhea, the occurrence of diarrhea cases in industrialized countries, and outbreaks of diarrhea in Europe and Asia have been reported. In the spring of 2011, a large outbreak of hemolytic-uremic syndrome (HUS) and hemorrhagic colitis occurred in Germany due to an EAEC O104:H4 strain, causing 54 deaths and 855 cases of HUS. This strain produces the potent Shiga toxin along with the aggregative fimbriae. An outbreak of urinary tract infection associated with EAEC in Copenhagen, Denmark, occurred in 1991; this involved extensive production of biofilm, an important characteristic of the pathogenicity of EAEC. However, the heterogeneity of EAEC continues to complicate diagnostics and also our understanding of pathogenicity.
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19
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Ghosh S, Pazhani GP, Niyogi SK, Nataro JP, Ramamurthy T. Genetic characterization of Shigella spp. isolated from diarrhoeal and asymptomatic children. J Med Microbiol 2014; 63:903-910. [PMID: 24790083 DOI: 10.1099/jmm.0.070912-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Phenotypic and genetic characteristics of Shigella spp. isolated from diarrhoeal and asymptomatic children aged up to 5 years were analysed in this study. In total, 91 and 17 isolates were identified from diarrhoeal (case) and asymptomatic (control) children, respectively. All the isolates were tested for antimicrobial resistance, the presence of integrons, plasmid-mediated quinolone resistance (PMQR), virulence-associated genes and Shigella pathogenicity island (SH-PAI). The majority of the Shigella spp. from cases (68.1%) and controls (82.3%) were found to be resistant to fluoroquinolones. Integron carriage was detected more in cases (76.9%) than in controls (35.5%). Atypical class 1 integron was detected exclusively in Shigella flexneri from cases but not from the controls. PMQR genes such as aac(6')-Ib-cr and qnrS1 were detected in 82.4 and 14.3% of the isolates from cases and in 53 and 17.6% in controls, respectively. Shigella isolates from cases as well as from controls were positive for the invasive plasmid antigen H-encoding gene ipaH. The other virulence genes such as virF, sat, setA, setB, sen and ial were detected in Shigella isolates in 80.2, 49.4, 27.4, 27.4, 80.2 and 79.1% of cases and in 64.7, 52.9, 17.6, 17.6, 64.7 and 64.7% of controls, respectively. The entire SH-PAI was detected in S. flexneri serotype 2a from cases and controls. In an isolate from a control child, the SH-PAI was truncated. Integrons, PMQR and virulence-encoding genes were detected more frequently in cases than in controls. In diarrhoea endemic areas, asymptomatic carriers may play a crucial role in the transmission of multidrug-resistant Shigella spp. with all the putative virulence genes.
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Affiliation(s)
- Santanu Ghosh
- Division of Bacteriology, National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Gururaja P Pazhani
- Division of Bacteriology, National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Swapan Kumar Niyogi
- Division of Bacteriology, National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - James P Nataro
- University of Virginia, School of Medicine, Charlottesville, VA, USA
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Estrada-Garcia T, Perez-Martinez I, Bernal-Reynaga R, Zaidi MB. Enteroaggregative coli: A Pathogen Bridging the North and South. CURRENT TROPICAL MEDICINE REPORTS 2014; 1:88-96. [PMID: 24892007 DOI: 10.1007/s40475-014-0018-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Enteroaggregative Escherichia coli (EAEC) is a heterogeneous emerging enteric pathogen. Identified during the 1980's when EAEC strains where isolated from cases of acute and persistent diarrhea among infants from developing countries and of traveler's diarrhea. Subsequently, EAEC strains were linked with foodborne outbreaks and diarrhea illness in adults and children from industrialized countries, HIV-infected subjects and stunting of malnourished poor children. Nowadays, EAEC is increasingly recognized as a major cause of acute diarrhea in children recurring hospitalization and of traveler's diarrhea worldwide. EAEC strains defining phenotype is the aggregative adherence (AA) pattern on epithelial cells. AggR a transcriptional regulator of several EAEC virulence genes has been a key factor in both understanding EAEC pathogenesis and defining typical EAEC (tEAEC) strains. EAEC virulence genes distribution among these strains is highly variable. Present challenges are the identification of key virulence genes and how they coordinately function in the setting of enteric disease.
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Affiliation(s)
| | | | | | - Mussaret B Zaidi
- Microbiology Research Laboratory and Pediatric Emergency Department, Hospital General O'Horán, Mérida, Yucatán, México ; Infectious Diseases Research Unit, Hospital Regional de Alta Especialidad de La Península de Yucatán, Mérida, Yucatán, México
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Saha DR, Guin S, Krishnan R, Nag D, Koley H, Shinoda S, Ramamurthy T. Inflammatory diarrhea due to enteroaggregative Escherichia coli: evidence from clinical and mice model studies. Gut Pathog 2013; 5:36. [PMID: 24294997 PMCID: PMC4176733 DOI: 10.1186/1757-4749-5-36] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 10/27/2013] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND This study was conducted to determine the role of enteroaggregative Escherichia coli (EAEC) in inflammatory diarrhea among hospitalized patients in Kolkata. The inflammatory pathogenesis of EAEC was established in mice model and histopathological studies. Presence of fecal leucocytes (FLCs) can be suspected for EAEC infection solely or as a mixed with other enteric pathogens. METHODS Active surveillance was conducted for 2 years on 2 random days per week with every 5th patient admitted to the Infectious Diseases Hospital (IDH). Diarrheal samples were processed by conventional culture, microscopy, ELISA and molecular methods. Two EAEC isolated as sole pathogens were examined in mice after induced intestinal infection. The intestinal tissue samples were processed to analyze the histological changes. RESULTS Of the 2519 samples screened, fecal leucocytes, erythrocytes and occult blood were detected in 1629 samples. Most of the patients had acute watery diarrhea (75%) and vomiting (78%). Vibrio cholerae O1 was the main pathogen in patients of 5-10 years age group (33%). Shigellosis was more in children from 2-5 years of age (19%), whereas children <2 years appeared to be susceptible for infection caused by EAEC (16%). When tested for the pathogenicity, the EAEC strains colonized well and caused inflammatory infection in the gut mucosa of BALB/C mice. CONCLUSION This hospital-based surveillance revealed prevalence of large number of inflammatory diarrhea. EAEC was the suspected pathogen and <2 years children appeared to be the most susceptible age group. BALB/C mice may be a suitable animal model to study the EAEC-mediated pathogenesis.
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Affiliation(s)
- Dhira Rani Saha
- Division of Histology & Electron microscopy, National Institute of Cholera and Enteric Diseases, P-33, C,I,T Road, Scheme XM, Beliaghata, Kolkata 700 010, West Bengal, India.
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22
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Croxen MA, Law RJ, Scholz R, Keeney KM, Wlodarska M, Finlay BB. Recent advances in understanding enteric pathogenic Escherichia coli. Clin Microbiol Rev 2013; 26:822-80. [PMID: 24092857 PMCID: PMC3811233 DOI: 10.1128/cmr.00022-13] [Citation(s) in RCA: 817] [Impact Index Per Article: 74.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Although Escherichia coli can be an innocuous resident of the gastrointestinal tract, it also has the pathogenic capacity to cause significant diarrheal and extraintestinal diseases. Pathogenic variants of E. coli (pathovars or pathotypes) cause much morbidity and mortality worldwide. Consequently, pathogenic E. coli is widely studied in humans, animals, food, and the environment. While there are many common features that these pathotypes employ to colonize the intestinal mucosa and cause disease, the course, onset, and complications vary significantly. Outbreaks are common in developed and developing countries, and they sometimes have fatal consequences. Many of these pathotypes are a major public health concern as they have low infectious doses and are transmitted through ubiquitous mediums, including food and water. The seriousness of pathogenic E. coli is exemplified by dedicated national and international surveillance programs that monitor and track outbreaks; unfortunately, this surveillance is often lacking in developing countries. While not all pathotypes carry the same public health profile, they all carry an enormous potential to cause disease and continue to present challenges to human health. This comprehensive review highlights recent advances in our understanding of the intestinal pathotypes of E. coli.
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Chattaway MA, Harris R, Jenkins C, Tam C, Coia JE, Gray J, Iturriza-Gomara M, Wain J. Investigating the link between the presence of enteroaggregative Escherichia coli and infectious intestinal disease in the United Kingdom, 1993 to 1996 and 2008 to 2009. ACTA ACUST UNITED AC 2013; 18. [PMID: 24079400 DOI: 10.2807/1560-7917.es2013.18.37.20582] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
There are an estimated 17 million human diarrhoea cases annually in the United Kingdom. In 2008 and 2009, enteroaggregative E. coli (EAEC) were identified in 1.9% of stools. However, it remains unclear whether there is a causal link between presence of EAEC and disease. This study used bacterial load, the presence of co-infections and demographic data to assess if EAEC was independently associated with intestinal infectious disease. Quantitative real-time PCR data (Ct values) generated directly from stool specimens for several pathogen targets were analysed to identify multiple pathogens, including EAEC, in the stools of cases and healthy controls. Sensitivity and specificity using Ct value (60% and 60%) was not useful for identifying cases or controls, but an independent association between disease and EAEC presence was demonstrated: multivariate logistic regression for EAEC presence (odds ratio: 2.41; 95% confidence interval: 1.78–3.26; p<0.001). The population-attributable fraction was 3.3%. The group of bacteria known as EAEC are associated with gastrointestinal disease in at least half of the cases with EAEC positive stools. We conclude that the current definition of EAEC, by plasmid gene detection, includes true pathogens as well as non-pathogenic variants.
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Affiliation(s)
- M A Chattaway
- Gastrointestinal Bacteria Reference Unit, Public Health England, Colindale, London, United Kingdom
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24
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Nüesch-Inderbinen MT, Hofer E, Hächler H, Beutin L, Stephan R. Characteristics of enteroaggregative Escherichia coli isolated from healthy carriers and from patients with diarrhoea. J Med Microbiol 2013; 62:1828-1834. [PMID: 24008499 DOI: 10.1099/jmm.0.065177-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The aim of this study was to compare the virulence characteristics and phylogenetic features of enteroaggregative Escherichia coli (EAEC) strains from adults with and without diarrhoea and to search for associations between the analysed genes and carrier or diarrhoeagenic strains, respectively. Faecal samples of 487 healthy humans were screened for EAEC strains and compared with isolates from diarrhoeal patients. Virulence and virulence-associated gene typing, serotyping, multilocus sequence typing and antibiotic susceptibility testing were performed for characterization of the isolates. Characteristics significantly linked to carrier strains or to diarrhoeagenic strains were determined. From 487 stool samples, 24 EAEC strains were obtained. Comparison with strains originating from diseased persons showed a statistically significant association of the genes sat (P = 0.002) and agg3C (P = 0.0139) with the carrier strains, and of pCVD432 (P = 0.0001), aap (P = 0.003), aggR (P = 0.0048) and air (P = 0.031) with the diarrhoeagenic strains. Our study indicates that a certain subset of EAEC is unrelated to diarrhoea, for which sat and agg3C may be markers. Our results further suggest that diarrhoeagenic EAEC strains are distinguishable from carrier strains and suggest that, in addition to well-established markers such as pCVD432 and aggR, aap and air may be useful additional markers to define EAEC as an aetiological agent of diarrhoea in adults.
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Affiliation(s)
| | - Eveline Hofer
- Institute for Food Safety and Hygiene, Vetsuisse Faculty University of Zurich, Zurich, Switzerland
| | - Herbert Hächler
- Institute for Food Safety and Hygiene, Vetsuisse Faculty University of Zurich, Zurich, Switzerland
| | - Lothar Beutin
- National Reference Laboratory for Escherichia coli (NRL-E. coli), Federal Institute for Risk Assessment, Berlin, Germany
| | - Roger Stephan
- Institute for Food Safety and Hygiene, Vetsuisse Faculty University of Zurich, Zurich, Switzerland
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25
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Philipson CW, Bassaganya-Riera J, Viladomiu M, Pedragosa M, Guerrant RL, Roche JK, Hontecillas R. The role of peroxisome proliferator-activated receptor γ in immune responses to enteroaggregative Escherichia coli infection. PLoS One 2013; 8:e57812. [PMID: 23469071 PMCID: PMC3585146 DOI: 10.1371/journal.pone.0057812] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Accepted: 01/25/2013] [Indexed: 12/24/2022] Open
Abstract
Background Enteroaggregative Escherichia coli (EAEC) is recognized as an emerging cause of persistent diarrhea and enteric disease worldwide. Mucosal immunity towards EAEC infections is incompletely understood due in part to the lack of appropriate animal models. This study presents a new mouse model and investigates the role of peroxisome proliferator-activated receptor gamma (PPARγ) in the modulation of host responses to EAEC in nourished and malnourished mice. Methods/Principal Findings Wild-type and T cell-specific PPARγ null C57BL/6 mice were fed protein-deficient diets at weaning and challenged with 5×109cfu EAEC strain JM221 to measure colonic gene expression and immune responses to EAEC. Antigen-specific responses to E. coli antigens were measured in nourished and malnourished mice following infection and demonstrated the immunosuppressive effects of malnutrition at the cellular level. At the molecular level, both pharmacological blockade and deletion of PPARγ in T cells resulted in upregulation of TGF-β, IL-6, IL-17 and anti-microbial peptides, enhanced Th17 responses, fewer colonic lesions, faster clearance of EAEC, and improved recovery. The beneficial effects of PPARγ blockade on weight loss and EAEC clearance were abrogated by neutralizing IL-17 in vivo. Conclusions Our studies provide in vivo evidence supporting the beneficial role of mucosal innate and effector T cell responses on EAEC burden and suggest pharmacological blockade of PPARγ as a novel therapeutic intervention for EAEC infection.
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Affiliation(s)
- Casandra W. Philipson
- Nutritional Immunology and Molecular Medicine Laboratory, Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, Virginia, United States of America
- Center for Modeling Immunity to Enteric Pathogens, Virginia Tech, Blacksburg, Virginia, United States of America
| | - Josep Bassaganya-Riera
- Nutritional Immunology and Molecular Medicine Laboratory, Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, Virginia, United States of America
- Center for Modeling Immunity to Enteric Pathogens, Virginia Tech, Blacksburg, Virginia, United States of America
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia, United States of America
| | - Monica Viladomiu
- Nutritional Immunology and Molecular Medicine Laboratory, Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, Virginia, United States of America
- Center for Modeling Immunity to Enteric Pathogens, Virginia Tech, Blacksburg, Virginia, United States of America
| | - Mireia Pedragosa
- Nutritional Immunology and Molecular Medicine Laboratory, Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, Virginia, United States of America
- Center for Modeling Immunity to Enteric Pathogens, Virginia Tech, Blacksburg, Virginia, United States of America
| | - Richard L. Guerrant
- Division of Infectious Diseases and International Health, Center for Global Health, University of Virginia, Charlottesville, Virginia, United States of America
| | - James K. Roche
- Division of Infectious Diseases and International Health, Center for Global Health, University of Virginia, Charlottesville, Virginia, United States of America
| | - Raquel Hontecillas
- Nutritional Immunology and Molecular Medicine Laboratory, Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, Virginia, United States of America
- Center for Modeling Immunity to Enteric Pathogens, Virginia Tech, Blacksburg, Virginia, United States of America
- * E-mail:
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26
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Characterization of the AggR regulon in enteroaggregative Escherichia coli. Infect Immun 2012; 81:122-32. [PMID: 23090962 DOI: 10.1128/iai.00676-12] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AggR is a transcriptional regulator of enteroaggregative Escherichia coli (EAEC) and has been proposed as the defining factor for typical EAEC strains. Expression of multiple putative virulence factors, including the aggregative adherence fimbriae (AAF), dispersin, the dispersin translocator Aat, and the Aai type VI secretion system, have been found to be regulated by AggR. Here, we confirm the existence of at least 44 AggR-regulated genes using DNA microarray and real-time quantitative reverse transcription-PCR (qRT-PCR); these genes include chromosomal and plasmid-borne loci and 19 previously unsuspected genes. Two previously uncharacterized virulence plasmid-encoded open reading frames (ORFs) (designated ORF3 and ORF4) exhibit significant identity with isoprenoid biosynthesis genes of Bacteria and Archaea. The predicted ORF4 product is closely related to isopentenyl isomerase (IDI) enzymes, whereas the predicted product of the adjacent ORF3 exhibits an aspartate-rich region that is common among trans-isoprenyl phosphate synthases. We show that mutations in these ORFs confer changes in bacterial surface properties. AggR coordinately controls expression of a large number of EAEC genes.
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Boll EJ, McCormick BA. A new understanding of enteroaggregative Escherichia coli as an inflammatory pathogen. Cell Adh Migr 2012; 6:413-8. [PMID: 23076052 DOI: 10.4161/cam.21241] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Enteroaggregative Escherichia coli (EAEC) is an important cause of endemic and epidemic diarrheal disease worldwide. Although not classically considered an inflammatory pathogen in the style of Shigella and Salmonella species, clinical data from patients suggests that inflammatory responses may play an important role during EAEC disease. However, the specific role of inflammation during EAEC pathogenesis has not been investigated in detail. To better understand how EAEC may induce inflammation, we have focused our attention on the intimate interactions between EAEC and the host epithelium and the subsequent induction of host cell signaling events leading to innate immune responses. Here, we discuss our recent findings on the signaling pathway by which EAEC promotes transepithelial migration of polymorphonuclear leukocytes (PMNs), the role of aggregative adherence fimbriae in triggering this event and the implementation of human intestinal xenografts in immunodeficient mice for studying EAEC pathogenesis in vivo. Our findings suggest that EAEC shares conserved mechanisms of inducing PMN recruitment with other intestinal pathogens, providing new insight into the potential pathological consequences of EAEC-induced inflammation.
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Affiliation(s)
- Erik J Boll
- Department of Microbiology and Physiological Systems; University of Massachusetts Medical School; Worcester, MA, USA
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Estrada-Garcia T, Navarro-Garcia F. Enteroaggregative Escherichia coli pathotype: a genetically heterogeneous emerging foodborne enteropathogen. ACTA ACUST UNITED AC 2012; 66:281-98. [PMID: 22775224 DOI: 10.1111/j.1574-695x.2012.01008.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Revised: 07/03/2012] [Accepted: 07/03/2012] [Indexed: 11/28/2022]
Abstract
Until now, a common feature that defines the enteroaggregative Escherichia coli (EAEC) strains is the ability to produce a 'stacked-brick' appearance on epithelial cells, but it does not distinguish between pathogenic and nonpathogenic strains. Numerous adhesins, toxins, and proteins associated with virulence have been described, as well as multiple factors contributing to EAEC-induced inflammation. None of these factors are found in all EAEC isolates, and no single factor has ever been implicated in EAEC virulence. The European outbreak of Shiga-toxin-producing EAEC raises its pathogenic potential and interest on finding the true pathogenic factors that may define this pathotype. EAEC were first associated with persistent diarrhea in infants from developing countries, since then they have increasingly been linked as a cause of acute and persistent diarrhea in young infants and children in developing and industrialized countries, individuals infected with human immunodeficiency virus, as a cause of acute diarrhea in travelers from industrialized regions, and with foodborne outbreaks. A major effect of EAEC infection is on the malnourished children in developing countries. Here, we will discuss the EAEC public health relevance and their complexity because of the strain heterogeneity regarding their pathogenesis, identification, diagnosis, lineage, epidemiology, and clinical manifestations.
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Affiliation(s)
- Teresa Estrada-Garcia
- Department of Molecular Biomedicine, Centro de Investigación y de Estudios Avanzados del IPN, México DF, Mexico
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Fecal leukocytes in children infected with diarrheagenic Escherichia coli. J Clin Microbiol 2011; 49:1376-81. [PMID: 21325554 DOI: 10.1128/jcm.02199-10] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The purpose of this study was to determine the presence and quantity of fecal leukocytes in children infected with diarrheagenic Escherichia coli and to compare these levels between diarrhea and control cases. We analyzed 1,474 stool samples from 935 diarrhea episodes and 539 from healthy controls of a cohort study of children younger than 2 years of age in Lima, Peru. Stools were analyzed for common enteric pathogens, and diarrheagenic E. coli isolates were studied by a multiplex real-time PCR. Stool smears were stained with methylene blue and read by a blinded observer to determine the number of polymorphonuclear leukocytes per high-power field (L/hpf). Fecal leukocytes at >10 L/hpf were present in 11.8% (110/935) of all diarrheal episodes versus 1.1% (6/539) in controls (P < 0.001). Among stool samples with diarrheagenic E. coli as the only pathogen isolated (excluding coinfection), fecal leukocytes at >10 L/hpf were present in 8.5% (18/212) of diarrhea versus 1.3% (2/157) of control samples (P < 0.01). Ninety-five percent of 99 diarrheagenic E. coli diarrhea samples were positive for fecal lactoferrin. Adjusting for the presence of blood in stools, age, sex, undernutrition, and breastfeeding, enterotoxigenic E. coli (ETEC) isolation as a single pathogen, excluding coinfections, was highly associated with the presence of fecal leukocytes (>10 L/hpf) with an odds ratio (OR) of 4.1 (95% confidence interval [CI], 1.08 to 15.51; P < 0.05). Although diarrheagenic E. coli was isolated with similar frequencies in diarrhea and control samples, clearly it was associated with a more inflammatory response during symptomatic infection; however, in general, these pathogens elicited a mild inflammatory response.
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Opintan JA, Newman MJ, Ayeh-Kumi PF, Affrim R, Gepi-Attee R, Sevilleja JEAD, Roche JK, Nataro JP, Warren CA, Guerrant RL. Pediatric diarrhea in southern Ghana: etiology and association with intestinal inflammation and malnutrition. Am J Trop Med Hyg 2010; 83:936-43. [PMID: 20889896 DOI: 10.4269/ajtmh.2010.09-0792] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Diarrhea is a major public health problem that affects the development of children. Anthropometric data were collected from 274 children with (N = 170) and without (N = 104) diarrhea. Stool specimens were analyzed by conventional culture, polymerase chain reaction for enteroaggregative Escherichia coli (EAEC), Shigella, Cryptosporidium, Entamoeba, and Giardia species, and by enzyme-linked immunosorbent assay for fecal lactoferrin levels. About 50% of the study population was mildly to severely malnourished. Fecal lactoferrin levels were higher in children with diarrhea (P = 0.019). Children who had EAEC infection, with or without diarrhea, had high mean lactoferrin levels regardless of nutritional status. The EAEC and Cryptosporidium were associated with diarrhea (P = 0.048 and 0.011, respectively), and malnourished children who had diarrhea were often co-infected with both Cryptosporidium and EAEC. In conclusion, the use of DNA-biomarkers revealed that EAEC and Cryptosporidium were common intestinal pathogens in Accra, and that elevated lactoferrin was associated with diarrhea in this group of children.
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Affiliation(s)
- Japheth A Opintan
- Department of Microbiology, University of Ghana Medical School, Accra, Ghana.
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