title: Virulence determinants in enteroaggregative Escherichia coli from North India and their interaction in in vitro organ culture system.
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.
authors: Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India.
authors: Deepika
authors: D
authors: Gupta
authors: Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India.
authors: Monica
authors: M
authors: Sharma
authors: Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India.
authors: Subendu
authors: S
authors: Sarkar
authors: Department of Gastroenterology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India.
authors: B R
authors: BR
authors: Thapa
authors: Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India superoxide14@gmail.com.
authors: Anuradha
authors: A
authors: Chakraborti
mesh_terms: D001422:Bacterial Adhesion; D001706:Biopsy; D002648:Child; D016207:Cytokines / Q000276:immunology; D003967:Diarrhea / Q000382:microbiology; D004386:Duodenum / Q000382:microbiology / Q000473:pathology; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology; D029968:Escherichia coli Proteins / Q000235:genetics; D035021:Factor For Inversion Stimulation Protein / Q000235:genetics; D005243:Feces / Q000382:microbiology; D036781:Fimbriae Proteins / Q000235:genetics; D010861:Fimbriae, Bacterial / Q000235:genetics; D054884:Host-Pathogen Interactions; D006801:Humans; D007194:India / Q000453:epidemiology; D007249:Inflammation; D015850:Interleukin-6 / Q000276:immunology; D016209:Interleukin-8 / Q000276:immunology; D009924:Organ Culture Techniques; D014409:Tumor Necrosis Factor-alpha; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics*
chemical_list: C479827:AAP protein, E coli; C079725:AggA protein, E coli; D016207:Cytokines; D029968:Escherichia coli Proteins; D035021:Factor For Inversion Stimulation Protein; C501034:Fis protein, E coli; C508600:IL6 protein, human; D015850:Interleukin-6; D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha; D037521:Virulence Factors; D036781:Fimbriae Proteins
keywords: AAF; EAEC; IVOC; diarrhoeagenic E. coli; inflammatory response