title: Diffusely adherent Escherichia coli strains isolated from children and adults constitute two different populations.
abstract: BACKGROUND
  Diffusely adherent Escherichia coli (DAEC) have been considered a diarrheagenic category of E. coli for which several potential virulence factors have been described in the last few years. Despite this, epidemiological studies involving DAEC have shown inconsistent results. In this work, two different collections of DAEC possessing Afa/Dr genes, from children and adults, were studied regarding characteristics potentially associated to virulence.
  
  
  RESULTS
  DAEC strains were recovered in similar frequencies from diarrheic and asymptomatic children, and more frequently from adults with diarrhea (P < 0.01) than from asymptomatic adults. Association with diarrhea (P < 0.05) was found for SAT-positive strains recovered from children and for curli-positive strains recovered from adults. Mixed biofilms involving DAEC and a Citrobacter freundii strain have shown an improved ability to form biofilms in relation to the monocultures. Control strains have shown a greater diversity of Afa/Dr adhesins and higher frequencies of cellulose, TTSS, biofilm formation and induction of IL-8 secretion than strains from cases of diarrhea in children.
  
  
  CONCLUSIONS
  DAEC strains possessing Afa/Dr genes isolated from children and adults represent two different bacterial populations. DAEC strains carrying genes associated to virulence can be found as part of the normal microbiota present in asymptomatic children.
authors: Laboratório de Microbiologia, Departamento de Biologia Celular, Universidade de Brasília, Brasília, DF, 70910-900, Brazil.
authors: Rosane
authors: R
authors: Mansan-Almeida
authors: Alex Leite
authors: AL
authors: Pereira
authors: Loreny Gimenes
authors: LG
authors: Giugliano
mesh_terms: D000328:Adult; D018441:Biofilms / Q000254:growth & development; D002675:Child, Preschool; D016971:Citrobacter freundii / Q000502:physiology; D003967:Diarrhea / Q000382:microbiology*; D004926:Escherichia coli / Q000145:classification* / Q000302:isolation & purification* / Q000472:pathogenicity / Q000502:physiology; D004927:Escherichia coli Infections / Q000382:microbiology*; D005838:Genotype; D006801:Humans; D007223:Infant; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D037521:Virulence Factors
references: J Clin Microbiol. 2006 Dec;44(12):4550-2
references: 17021054
references: Infect Immun. 2000 Jan;68(1):64-71
references: 10603369
references: J Neurosci Res. 2008 Aug 1;86(10):2303-13
references: 18418902
references: J Infect Dis. 1993 Mar;167(3):755-8
references: 8440943
references: Cell Microbiol. 2007 Jan;9(1):204-21
references: 16903846
references: J Clin Microbiol. 1999 Nov;37(11):3458-64
references: 10523534
references: J Food Prot. 2007 Jun;70(6):1339-45
references: 17612061
references: J Infect Dis. 2007 Feb 1;195(3):366-74
references: 17205475
references: BMC Genomics. 2007 Jul 05;8:215
references: 17615075
references: Infect Immun. 2004 Oct;72(10):5741-9
references: 15385473
references: FEMS Microbiol Ecol. 2011 Aug;77(2):404-12
references: 21539582
references: J Infect Dis. 1996 Nov;174(5):1124-6
references: 8896522
references: J Infect Dev Ctries. 2012 Feb 13;6(2):102-8
references: 22337837
references: BMC Microbiol. 2010 Feb 23;10:57
references: 20175929
references: Best Pract Res Clin Gastroenterol. 2004 Apr;18(2):323-36
references: 15123073
references: Am J Trop Med Hyg. 2004 Nov;71(5):687-90
references: 15569806
references: Microbiol Immunol. 2005;49(6):493-503
references: 15965296
references: Annu Rev Microbiol. 2006;60:131-47
references: 16704339
references: PLoS Biol. 2007 Jul;5(7):e177
references: 17594176
references: Clin Microbiol Rev. 2005 Apr;18(2):264-92
references: 15831825
references: Infect Immun. 2000 Oct;68(10):5979-90
references: 10992510
references: Nat Rev Microbiol. 2004 Feb;2(2):123-40
references: 15040260
references: Nature. 2001 Jul 26;412(6845):442-5
references: 11473319
references: APMIS. 2011 Jan;119(1):17-35
references: 21143523
references: Infect Genet Evol. 2003 Jul;3(2):111-7
references: 12809805
references: Proc Natl Acad Sci U S A. 2001 Feb 13;98(4):1883-8
references: 11172045
references: Appl Environ Microbiol. 2010 Mar;76(5):1545-54
references: 20080991
references: Clin Infect Dis. 2009 Dec 1;49(11):1694-702
references: 19857163
references: Nature. 2012 May 09;486(7402):222-7
references: 22699611
references: Infect Immun. 1996 Jun;64(6):1918-28
references: 8675288
references: J Med Microbiol. 2002 Jul;51(7):548-571
references: 12132770
references: Clinics (Sao Paulo). 2012;67(2):113-23
references: 22358235
references: J Clin Microbiol. 1992 May;30(5):1189-93
references: 1349900
references: J Infect Dis. 1985 Sep;152(3):550-9
references: 2863318
references: J Bacteriol. 2008 Nov;190(22):7479-90
references: 18790864
references: Am J Epidemiol. 1993 Nov 15;138(10):849-69
references: 8237973
references: Cell Microbiol. 2004 Sep;6(9):805-16
references: 15272862
references: Cell Host Microbe. 2009 Jul 23;6(1):45-53
references: 19616765
references: BMC Med. 2008 Aug 21;6:23
references: 18717995
references: Infect Immun. 1997 Jun;65(6):2011-8
references: 9169726
references: Science. 2005 Mar 25;307(5717):1915-20
references: 15790844
references: Science. 2002 Feb 1;295(5556):851-5
references: 11823641
references: Appl Environ Microbiol. 2008 May;74(9):2908-14
references: 18310437
references: Braz J Infect Dis. 2007 Feb;11(1):44-9
references: 17625726
references: Mol Microbiol. 2004 May;52(4):963-83
references: 15130118
references: Diagn Microbiol Infect Dis. 2010 Oct;68(2):117-22
references: 20846583
references: Infect Immun. 1993 Dec;61(12):5106-14
references: 7901162
references: Mol Microbiol. 2007 Apr;64(1):180-94
references: 17376081
references: Infect Immun. 1999 Aug;67(8):3989-97
references: 10417165
references: J Infect Dis. 2000 Feb;181(2):602-12
references: 10669344
references: J Infect Dis. 2004 Sep 15;190(6):1183-91
references: 15319870
references: Infect Immun. 2000 Jun;68(6):3554-63
references: 10816511
references: Mutat Res. 2007 Sep 1;622(1-2):58-69
references: 17612575
references: Mem Inst Oswaldo Cruz. 2004 Oct;99(6):545-52
references: 15558161
references: Microbiol Immunol. 2010 Sep;54(9):491-501
references: 20840147
references: Environ Microbiol. 2010 Sep;12(9):2385-97
references: 20636374
references: Proc Natl Acad Sci U S A. 2011 Mar 15;108 Suppl 1:4578-85
references: 20668239
references: J Clin Microbiol. 2008 May;46(5):1752-7
references: 18322059
references: Int J Med Microbiol. 2005 Oct;295(6-7):357-71
references: 16238013
references: Infect Immun. 2003 Apr;71(4):1774-83
references: 12654791
references: FEMS Microbiol Lett. 2006 Mar;256(2):185-94
references: 16499605
references: Mol Microbiol. 2000 Apr;36(1):10-23
references: 10760159
references: Infect Immun. 2001 Apr;69(4):2659-65
references: 11254632
references: Philos Trans R Soc Lond B Biol Sci. 2000 May 29;355(1397):695-704
references: 10874741
references: FEMS Microbiol Lett. 2003 Oct 24;227(2):249-53
references: 14592716
references: J Allergy Clin Immunol. 2001 Oct;108(4):516-20
references: 11590374
references: Semin Pediatr Infect Dis. 2004 Oct;15(4):266-71
references: 15494951
references: Trans R Soc Trop Med Hyg. 2010 Jul;104(7):504-6
references: 20307897
references: Mol Microbiol. 2001 Sep;41(5):999-1014
references: 11555282
references: J Clin Microbiol. 2002 Feb;40(2):645-8
references: 11825986
references: Infect Immun. 2002 Oct;70(10):5503-11
references: 12228276
references: Infect Immun. 2002 Jan;70(1):395-9
references: 11748206
references: Rev Inst Med Trop Sao Paulo. 2000 Jan-Feb;42(1):9-15
references: 10742721
references: Exp Gerontol. 2005 May;40(5):426-37
references: 15919595
references: Jpn J Infect Dis. 2009 Jul;62(4):318-23
references: 19628916
references: Neurobiol Aging. 1998 Nov-Dec;19(6):561-8
references: 10192215