title: Biofilm formation and binding specificities of CFA/I, CFA/II and CS2 adhesions of enterotoxigenic Escherichia coli and Cfae-R181A mutant.
abstract: Enterotoxigenic Escherichia coli (ETEC) strains are leading causes of childhood diarrhea in developing countries. Adhesion is the first step in pathogenesis of ETEC infections and ETEC pili designated colonization factor antigens (CFAs) are believed to be important in the biofim formation, colonization and host cell adhesions. As a first step, we have determined the biofilm capability of ETEC expressing various types of pili (CFA/I, CfaE-R181A mutant/CfaE tip mutant, CFA/II and CS2). Further, enzyme-linked immunosorbent assay (ELISA) assay were developed to compare the binding specificity of CFA/I, CFA/II (CS1 - CS3) and CS2 of ETEC, using extracted pili and piliated bacteria. CFA/II strain (E24377a) as well as extracted pili exhibited significantly higher binding both in biofilm and ELISA assays compared to non piliated wild type E24377a, CFA/I and CS2 strains. This indicates that co-expression of two or more CS2 in same strain is more efficient in increasing adherence. Significant decrease in binding specificity of DH5αF'lacI (q)/∆cotD (CS2) strain and MC4100/pEU2124 (CfaE-R181A) mutant strain indicated the important contribution of tip proteins in adherence assays. However, CS2 tip mutant strain (DH5αF'lacI (q)/pEU5881) showed that this specific residue may not be important as adhesions in these strains. In summary, our data suggest that pili, their minor subunits are important for biofilm formation and adherence mechanisms. Overall, the functional reactivity of strains co expressing various antigens, particularly minor subunit antigen observed in this study suggest that fewer antibodies may be required to elicit immunity to ETEC expressing a wider array of related pili.
authors.affiliation: Department of Zoology, Government College University , Lahore , Pakistan ; The University of Western Australia, School of Biomedical, Biomolecular & Chemical Sciences Microbiology M502 , 35 Stirling Hwy Crawley WA 6009.
authors.forename: Iram
authors.initials: I
authors.lastname: Liaqat
authors.forename: Harry
authors.initials: H
authors.lastname: Sakellaris
keywords: Biofilm formation;; CFA/I; CFA/II; CS2; ELISA assays; ETEC; R181-cotD; asialo-GM1; dsc19CotD(His)6
references.citation: Infect Immun. 1990 Jul;58(7):2361-6
references.pmid: 2114364
references.citation: J Appl Microbiol. 2007 May;102(5):1187-96
references.pmid: 17448154
references.citation: J Bacteriol. 2010 Jun;192(11):2791-800
references.pmid: 20348256
references.citation: FEMS Microbiol Lett. 1990 Jan 1;54(1-3):107-12
references.pmid: 1969827
references.citation: Infect Immun. 1985 Jun;48(3):824-31
references.pmid: 2860070
references.citation: FEMS Microbiol Lett. 1990 Nov;60(3):289-92
references.pmid: 1982102
references.citation: J Bacteriol. 1999 Mar;181(5):1694-7
references.pmid: 10049406
references.citation: Cell Mol Life Sci. 2009 Feb;66(4):613-35
references.pmid: 18953686
references.citation: Science. 2003 Jul 4;301(5629):105-7
references.pmid: 12843396
references.citation: J Bacteriol. 2005 Feb;187(4):1455-64
references.pmid: 15687210
references.citation: Cell. 2002 Nov 15;111(4):543-51
references.pmid: 12437927
references.citation: Mol Microbiol. 1994 Feb;11(4):705-13
references.pmid: 7910938
references.citation: Infect Immun. 1979 Aug;25(2):738-48
references.pmid: 39896
references.citation: Infect Immun. 1991 Nov;59(11):3876-82
references.pmid: 1682253
references.citation: Contrib Microbiol. 2005;12:67-89
references.pmid: 15496777
references.citation: Gastrointest Endosc. 1998 Sep;48(3):250-7
references.pmid: 9744599
references.citation: Infect Immun. 1984 May;44(2):409-20
references.pmid: 6370866
references.citation: Vaccine. 2003 Jun 2;21(19-20):2548-55
references.pmid: 12744890
references.citation: Environ Microbiol. 2007 Feb;9(2):332-46
references.pmid: 17222132
references.citation: J Gen Microbiol. 1985 Sep;131(9):2319-26
references.pmid: 2866226
references.citation: Mol Microbiol. 2007 Mar;63(5):1372-84
references.pmid: 17302815
references.citation: Acta Crystallogr D Biol Crystallogr. 2006 Feb;62(Pt 2):157-64
references.pmid: 16421447
references.citation: Sci Am. 1993 Jan;268(1):82-9
references.pmid: 7678182
references.citation: Microb Pathog. 2010 Jun;48(6):230-8
references.pmid: 20227481
references.citation: Mol Microbiol. 1996 Aug;21(3):529-41
references.pmid: 8866477
references.citation: Infect Immun. 1992 Nov;60(11):4445-51
references.pmid: 1356928
references.citation: Curr Microbiol. 2010 Aug;61(2):148-56
references.pmid: 20111864
references.citation: J Mol Biol. 2008 Feb 22;376(3):614-20
references.pmid: 18166195