메뉴 건너뛰기




Volumn 80, Issue 3, 2014, Pages 1177-1184

Intimin gene (eae) subtype-based real-time PCR strategy for specific detection of shiga toxin-producing Escherichia coli serotypes O157:H7, O26:H11, O103:H2, O111:H8, and O145:H28 in cattle feces

Author keywords

[No Author keywords available]

Indexed keywords

ENTEROPATHOGENIC E. COLI; FECAL SAMPLES; GENETIC COMBINATIONS; REAL-TIME PCR; REAL-TIME PCR ASSAY; SEROGROUPS; SHIGA TOXIN-PRODUCING ESCHERICHIA COLI; SPECIFIC DETECTION;

EID: 84892981875     PISSN: 00992240     EISSN: 10985336     Source Type: Journal    
DOI: 10.1128/AEM.03161-13     Document Type: Article
Times cited : (27)

References (41)
  • 1
    • 33845388167 scopus 로고    scopus 로고
    • The emerging clinical importance of non-O157 Shiga toxin-producing Escherichia coli
    • Johnson KE, Thorpe CM, Sears CL. 2006. The emerging clinical importance of non-O157 Shiga toxin-producing Escherichia coli. Clin. Infect. Dis. 43:1587-1595. http://dx.doi.org/10.1086/509573.
    • (2006) Clin. Infect. Dis. , vol.43 , pp. 1587-1595
    • Johnson, K.E.1    Thorpe, C.M.2    Sears, C.L.3
  • 2
    • 84893007775 scopus 로고    scopus 로고
    • French Agency for Food, Environmental and Occupational Health and Safety (ANSES),Opinion of the French Food Safety Agency on the advisability of revising the definition of pathogenic STEC, specified in AFSSA's Opinion of 15 July 2008
    • ANSES, Maisons-Alfort, France.
    • French Agency for Food, Environmental and Occupational Health and Safety (ANSES). 2010. Opinion of the French Food Safety Agency on the advisability of revising the definition of pathogenic STEC, specified in AFSSA's Opinion of 15 July 2008. ANSES, Maisons-Alfort, France.
    • (2010)
  • 3
    • 0033981931 scopus 로고    scopus 로고
    • Typing of intimin genes in human and animal enterohemorrhagic and enteropathogenic Escherichia coli: characterization of a new intimin variant
    • Oswald E, Schmidt H, Morabito S, Karch H, Marches O, Caprioli A. 2000. Typing of intimin genes in human and animal enterohemorrhagic and enteropathogenic Escherichia coli: characterization of a new intimin variant. Infect. Immun. 68:64-71. http://dx.doi.org/10.1128/IAI.68.1.64-71.2000.
    • (2000) Infect. Immun. , vol.68 , pp. 64-71
    • Oswald, E.1    Schmidt, H.2    Morabito, S.3    Karch, H.4    Marches, O.5    Caprioli, A.6
  • 4
    • 0036136330 scopus 로고    scopus 로고
    • Molecular evolution of the intimin gene in O111 clones of pathogenic Escherichia coli
    • Tarr CL, Whittam TS. 2002. Molecular evolution of the intimin gene in O111 clones of pathogenic Escherichia coli. J. Bacteriol. 184:479-487. http://dx.doi.org/10.1128/JB.184.2.479-487.2002.
    • (2002) J. Bacteriol. , vol.184 , pp. 479-487
    • Tarr, C.L.1    Whittam, T.S.2
  • 5
    • 73949159257 scopus 로고    scopus 로고
    • Verocytotoxin-producing Escherichia coli (VTEC)
    • Karmali MA, Gannon V, Sargeant JM. 2010. Verocytotoxin-producing Escherichia coli (VTEC). Vet. Microbiol. 140:360-370. http://dx.doi.org /10.1016/j.vetmic.2009.04.011.
    • (2010) Vet. Microbiol. , vol.140 , pp. 360-370
    • Karmali, M.A.1    Gannon, V.2    Sargeant, J.M.3
  • 6
    • 79953685920 scopus 로고    scopus 로고
    • Escherichia coli O157:H7: animal reservoir and sources of human infection
    • Ferens WA, Hovde CJ. 2011. Escherichia coli O157:H7: animal reservoir and sources of human infection. Foodborne Pathog. Dis. 8:465-487. http: //dx.doi.org/10.1089/fpd.2010.0673.
    • (2011) Foodborne Pathog. Dis. , vol.8 , pp. 465-487
    • Ferens, W.A.1    Hovde, C.J.2
  • 7
    • 84888779304 scopus 로고    scopus 로고
    • ISO/TS 13136:2012: microbiology of food and animal feed
    • ISO.Real-time polymerase chain reaction (PCR)-based method for the detection of food-borne pathogens. Horizontal method for the detection of Shiga toxin-producing Escherichia coli (STEC) and the determination of O157, O111, O26, O103 and O145 serogroups. International Organization for Standardization, Geneva, Switzerland
    • ISO. 2012. ISO/TS 13136:2012: microbiology of food and animal feed. Real-time polymerase chain reaction (PCR)-based method for the detection of food-borne pathogens. Horizontal method for the detection of Shiga toxin-producing Escherichia coli (STEC) and the determination of O157, O111, O26, O103 and O145 serogroups. International Organization for Standardization, Geneva, Switzerland.
    • (2012)
  • 8
    • 84886280391 scopus 로고    scopus 로고
    • Technical specifications for the monitoring and reporting of verotoxigenic Escherichia coli (VTEC) on animals and food (VTEC surveys on animals and food)
    • European Food Safety Authority (EFSA)
    • European Food Safety Authority (EFSA). 2009. Technical specifications for the monitoring and reporting of verotoxigenic Escherichia coli (VTEC) on animals and food (VTEC surveys on animals and food). EFSA J. 7:1366-1409. http://dx.doi.org/10.2903/j.efsa.2009.1366.
    • (2009) EFSA J. , vol.7 , pp. 1366-1409
  • 9
    • 0037493309 scopus 로고    scopus 로고
    • Detection and characterization of verocytotoxin-producing Escherichia coli by automated 5= nuclease PCR assay
    • Nielsen EM, Andersen MT. 2003. Detection and characterization of verocytotoxin-producing Escherichia coli by automated 5= nuclease PCR assay. J. Clin. Microbiol. 41:2884-2893. http://dx.doi.org/10.1128/JCM .41.7.2884-2893.2003.
    • (2003) J. Clin. Microbiol. , vol.41 , pp. 2884-2893
    • Nielsen, E.M.1    Andersen, M.T.2
  • 11
    • 78650498951 scopus 로고    scopus 로고
    • Simplex and multiplex real-time PCR assays for the detection of flagellar (H-antigen) fliC alleles and intimin (eae) variants associated with enterohaemorrhagic Escherichia coli (EHEC) serotypes O26:H11, O103:H2, O111:H8, O145:H28 and O157:H7
    • Madic J, Peytavin de Garam C, Vingadassalon N, Oswald E, Fach P, Jamet E, Auvray F. 2010. Simplex and multiplex real-time PCR assays for the detection of flagellar (H-antigen) fliC alleles and intimin (eae) variants associated with enterohaemorrhagic Escherichia coli (EHEC) serotypes O26:H11, O103:H2, O111:H8, O145:H28 and O157:H7. J. Appl. Microbiol. 109: 1696-1705. http://dx.doi.org/10.1111/j.1365-2672.2010.04798.x.
    • (2010) J. Appl. Microbiol. , vol.109 , pp. 1696-1705
    • Madic, J.1    Peytavin de Garam, C.2    Vingadassalon, N.3    Oswald, E.4    Fach, P.5    Jamet, E.6    Auvray, F.7
  • 13
    • 0021825282 scopus 로고
    • The diarrheal response of humans to some classic serotypes of enteropathogenic Escherichia coli is dependent on a plasmid encoding an enteroadhesiveness factor
    • Levine MM, Nataro JP, Karch H, Baldini MM, Kaper JB, Black RE, Clements ML, O'Brien AD. 1985. The diarrheal response of humans to some classic serotypes of enteropathogenic Escherichia coli is dependent on a plasmid encoding an enteroadhesiveness factor. J. Infect. Dis. 152: 550-559. http://dx.doi.org/10.1093/infdis/152.3.550.
    • (1985) J. Infect. Dis. , vol.152 , pp. 550-559
    • Levine, M.M.1    Nataro, J.P.2    Karch, H.3    Baldini, M.M.4    Kaper, J.B.5    Black, R.E.6    Clements, M.L.7    O'Brien, A.D.8
  • 15
    • 2342579395 scopus 로고    scopus 로고
    • Detection by 5=-nuclease PCR of Shiga-toxin producing Escherichia coli O26, O55, O91, O103, O111, O113, O145 and O157:H7, associated with the world's most frequent clinical cases
    • Perelle S, Dilasser F, Grout J, Fach P. 2004. Detection by 5=-nuclease PCR of Shiga-toxin producing Escherichia coli O26, O55, O91, O103, O111, O113, O145 and O157:H7, associated with the world's most frequent clinical cases. Mol. Cell Probes 18:185-192. http://dx.doi.org/10 .1016/j.mcp.2003.12.004.
    • (2004) Mol. Cell Probes , vol.18 , pp. 185-192
    • Perelle, S.1    Dilasser, F.2    Grout, J.3    Fach, P.4
  • 16
    • 17644374069 scopus 로고    scopus 로고
    • Detection of Escherichia coli serogroup O103 by real-time polymerase chain reaction
    • Perelle S, Dilasser F, Grout J, Fach P. 2005. Detection of Escherichia coli serogroup O103 by real-time polymerase chain reaction. J. Appl. Microbiol. 98:1162-1168. http://dx.doi.org/10.1111/j.1365-2672.2005.02545.x.
    • (2005) J. Appl. Microbiol. , vol.98 , pp. 1162-1168
    • Perelle, S.1    Dilasser, F.2    Grout, J.3    Fach, P.4
  • 17
    • 41549106271 scopus 로고    scopus 로고
    • Novel differential and confirmation plating media for Shiga toxin-producing Escherichia coli serotypes O26, O103, O111, O145 and sorbitol-positive and-negative O157
    • Possé B, De Zutter L, Heyndrickx M, Herman L. 2008. Novel differential and confirmation plating media for Shiga toxin-producing Escherichia coli serotypes O26, O103, O111, O145 and sorbitol-positive and-negative O157. FEMS Microbiol. Lett. 282:124-131. http://dx.doi.org/10.1111/j .1574-6968.2008.01121.x.
    • (2008) FEMS Microbiol. Lett. , vol.282 , pp. 124-131
    • Possé, B.1    De Zutter, L.2    Heyndrickx, M.3    Herman, L.4
  • 19
    • 0031975950 scopus 로고    scopus 로고
    • Detection and characterization of Shiga toxigenic Escherichia coli by using multiplex PCR assays for stx1, stx2, eaeA, enterohemorrhagic E
    • Paton AW, Paton JC. 1998. Detection and characterization of Shiga toxigenic Escherichia coli by using multiplex PCR assays for stx1, stx2, eaeA, enterohemorrhagic E. coli hlyA, rfbO111, and rfbO157. J. Clin. Microbiol. 36:598-602.
    • (1998) coli hlyA, rfbO111, and rfbO157. J. Clin. Microbiol , vol.36 , pp. 598-602
    • Paton, A.W.1    Paton, J.C.2
  • 20
    • 84857094667 scopus 로고    scopus 로고
    • CTX-M-15 extended-spectrum beta-lactamase in a Shiga toxinproducing Escherichia coli isolate of serotype O111:H8
    • Valat C, Haenni M, Saras E, Auvray F, Forest K, Oswald E, Madec JY. 2012. CTX-M-15 extended-spectrum beta-lactamase in a Shiga toxinproducing Escherichia coli isolate of serotype O111:H8. Appl. Environ. Microbiol. 78:1308-1309. http://dx.doi.org/10.1128/AEM.06997-11.
    • (2012) Appl. Environ. Microbiol. , vol.78 , pp. 1308-1309
    • Valat, C.1    Haenni, M.2    Saras, E.3    Auvray, F.4    Forest, K.5    Oswald, E.6    Madec, J.Y.7
  • 21
    • 0027956341 scopus 로고
    • Nucleotide sequence analysis of enteropathogenic Escherichia coli (EPEC) adherence factor probe and development of PCR for rapid detection of EPEC harboring virulence plasmids
    • Franke J, Franke S, Schmidt H, Schwarzkopf A, Wieler LH, Baljer G, Beutin L, Karch H. 1994. Nucleotide sequence analysis of enteropathogenic Escherichia coli (EPEC) adherence factor probe and development of PCR for rapid detection of EPEC harboring virulence plasmids. J. Clin. Microbiol. 32:2460-2463.
    • (1994) J. Clin. Microbiol , vol.32 , pp. 2460-2463
    • Franke, J.1    Franke, S.2    Schmidt, H.3    Schwarzkopf, A.4    Wieler, L.H.5    Baljer, G.6    Beutin, L.7    Karch, H.8
  • 22
    • 0028942973 scopus 로고
    • Identification of enteropathogenic Escherichia coli by PCR-based detection of the bundleforming pilus gene
    • Gunzburg ST, Tornieporth NG, Riley LW. 1995. Identification of enteropathogenic Escherichia coli by PCR-based detection of the bundleforming pilus gene. J. Clin. Microbiol. 33:1375-1377.
    • (1995) J. Clin. Microbiol , vol.33 , pp. 1375-1377
    • Gunzburg, S.T.1    Tornieporth, N.G.2    Riley, L.W.3
  • 23
    • 79953268569 scopus 로고    scopus 로고
    • Identification of genetic markers for differentiation of Shiga toxinproducing, enteropathogenic, and avirulent strains of Escherichia coli O26
    • Bugarel M, Beutin L, Scheutz F, Loukiadis E, Fach P. 2011. Identification of genetic markers for differentiation of Shiga toxinproducing, enteropathogenic, and avirulent strains of Escherichia coli O26. Appl. Environ. Microbiol. 77:2275-2281. http://dx.doi.org/10.1128 /AEM.02832-10.
    • (2011) Appl. Environ. Microbiol. , vol.77 , pp. 2275-2281
    • Bugarel, M.1    Beutin, L.2    Scheutz, F.3    Loukiadis, E.4    Fach, P.5
  • 24
    • 33645707707 scopus 로고    scopus 로고
    • Standardization of pulsed-field gel electrophoresis protocols for the subtyping of Escherichia coli O157:H7, Salmonella, and Shigella for PulseNet
    • Ribot EM, Fair MA, Gautom R, Cameron DN, Hunter SB, Swaminathan B, Barrett TJ. 2006. Standardization of pulsed-field gel electrophoresis protocols for the subtyping of Escherichia coli O157:H7, Salmonella, and Shigella for PulseNet. Foodborne Pathog. Dis. 3:59-67. http://dx.doi .org/10.1089/fpd.2006.3.59.
    • (2006) Foodborne Pathog. Dis. , vol.3 , pp. 59-67
    • Ribot, E.M.1    Fair, M.A.2    Gautom, R.3    Cameron, D.N.4    Hunter, S.B.5    Swaminathan, B.6    Barrett, T.J.7
  • 26
    • 79953168070 scopus 로고    scopus 로고
    • Detection of Shiga toxin-producing Escherichia coli serotypes O26:H11, O103:H2, O111:H8, O145:H28, and O157:H7 in raw-milk cheeses by using multiplex real-time PCR
    • Madic J, Vingadassalon N, de Garam CP, Marault M, Scheutz F, Brugere H, Jamet E, Auvray F. 2011. Detection of Shiga toxin-producing Escherichia coli serotypes O26:H11, O103:H2, O111:H8, O145:H28, and O157:H7 in raw-milk cheeses by using multiplex real-time PCR. Appl. Environ. Microbiol. 77:2035-2041. http://dx.doi.org/10.1128/AEM.02089-10.
    • (2011) Appl. Environ. Microbiol. , vol.77 , pp. 2035-2041
    • Madic, J.1    Vingadassalon, N.2    de Garam, C.P.3    Marault, M.4    Scheutz, F.5    Brugere, H.6    Jamet, E.7    Auvray, F.8
  • 27
    • 84868323053 scopus 로고    scopus 로고
    • Predicting the presence of non-O157 Shiga toxin-producing Escherichia coli in ground beef by using molecular tests for Shiga toxins, intimin, and O serogroups
    • Bosilevac JM, Koohmaraie M. 2012. Predicting the presence of non-O157 Shiga toxin-producing Escherichia coli in ground beef by using molecular tests for Shiga toxins, intimin, and O serogroups. Appl. Environ. Microbiol. 78:7152-7155. http://dx.doi.org/10.1128/AEM.01508-12.
    • (2012) Appl. Environ. Microbiol. , vol.78 , pp. 7152-7155
    • Bosilevac, J.M.1    Koohmaraie, M.2
  • 28
    • 84865183437 scopus 로고    scopus 로고
    • Application of a real-time PCR-based system for monitoring of O26, O103, O111, O145 and O157 Shiga toxin-producing Escherichia coli in cattle at slaughter
    • 21 February, doi:10.1111/j.1863-2378.2012.01468.x.
    • Hofer E, Stephan R, Reist M, Zweifel C. 21 February 2012. Application of a real-time PCR-based system for monitoring of O26, O103, O111, O145 and O157 Shiga toxin-producing Escherichia coli in cattle at slaughter. Zoonoses Public Health. doi:10.1111/j.1863-2378.2012.01468.x.
    • (2012) Zoonoses Public Health.
    • Hofer, E.1    Stephan, R.2    Reist, M.3    Zweifel, C.4
  • 29
    • 77958113258 scopus 로고    scopus 로고
    • Prevalence of enterohemorrhagic Escherichia coli serotypes in Australian beef cattle
    • Barlow RS, Mellor GE. 2010. Prevalence of enterohemorrhagic Escherichia coli serotypes in Australian beef cattle. Foodborne Pathog. Dis. 7:1239-1245. http://dx.doi.org/10.1089/fpd.2010.0574.
    • (2010) Foodborne Pathog. Dis. , vol.7 , pp. 1239-1245
    • Barlow, R.S.1    Mellor, G.E.2
  • 30
    • 84860365107 scopus 로고    scopus 로고
    • Surveillance of verocytotoxigenic Escherichia coli in Irish bovine dairy herds
    • Lynch MJ, Fox EM, O'Connor L, Jordan K, Murphy M. 2012. Surveillance of verocytotoxigenic Escherichia coli in Irish bovine dairy herds. Zoonoses Public Health 59:264-271. http://dx.doi.org/10.1111/j.1863-2378.2011.01443.x.
    • (2012) Zoonoses Public Health , vol.59 , pp. 264-271
    • Lynch, M.J.1    Fox, E.M.2    O'Connor, L.3    Jordan, K.4    Murphy, M.5
  • 31
    • 62149106619 scopus 로고    scopus 로고
    • Evaluation of the 'GeneDisc' real-time PCR system for detection of enterohaemorrhagic Escherichia coli (EHEC) O26, O103, O111, O145 and O157 strains according to their virulence markers and their O-and H-antigen-associated genes
    • Beutin L, Jahn S, Fach P. 2009. Evaluation of the 'GeneDisc' real-time PCR system for detection of enterohaemorrhagic Escherichia coli (EHEC) O26, O103, O111, O145 and O157 strains according to their virulence markers and their O-and H-antigen-associated genes. J. Appl. Microbiol. 106:1122-1132. http://dx.doi.org/10.1111/j.1365-2672.2008 .04076.x.
    • (2009) J. Appl. Microbiol. , vol.106 , pp. 1122-1132
    • Beutin, L.1    Jahn, S.2    Fach, P.3
  • 33
    • 77956226521 scopus 로고    scopus 로고
    • Effect of the enrichment time and immunomagnetic separation on the detection of Shiga toxin-producing Escherichia coli O26, O103, O111, O145 and sorbitol positive O157 from artificially inoculated cattle faeces
    • Verstraete K, De Zutter L, Messens W, Herman L, Heyndrickx M, De Reu K. 2010. Effect of the enrichment time and immunomagnetic separation on the detection of Shiga toxin-producing Escherichia coli O26, O103, O111, O145 and sorbitol positive O157 from artificially inoculated cattle faeces. Vet. Microbiol. 145:106-112. http://dx.doi.org/10.1016/j .vetmic.2010.03.004.
    • (2010) Vet. Microbiol. , vol.145 , pp. 106-112
    • Verstraete, K.1    De Zutter, L.2    Messens, W.3    Herman, L.4    Heyndrickx, M.5    De Reu, K.6
  • 35
    • 33644886646 scopus 로고    scopus 로고
    • Sensitivity of Escherichia coli O157 detection in bovine feces assessed by broth enrichment followed by immunomagnetic separation and direct plating methodologies
    • LeJeune JT, Hancock DD, Besser TE. 2006. Sensitivity of Escherichia coli O157 detection in bovine feces assessed by broth enrichment followed by immunomagnetic separation and direct plating methodologies. J. Clin. Microbiol. 44:872-875. http://dx.doi.org/10.1128/JCM.44.3.872-875.2006.
    • (2006) J. Clin. Microbiol. , vol.44 , pp. 872-875
    • LeJeune, J.T.1    Hancock, D.D.2    Besser, T.E.3
  • 36
  • 38
    • 10744231312 scopus 로고    scopus 로고
    • Association of genomic O island 122 of Escherichia coli EDL 933 with verocytotoxin-producing Escherichia coli seropathotypes that are linked to epidemic and/or serious disease
    • Karmali MA, Mascarenhas M, Shen S, Ziebell K, Johnson S, Reid-Smith R, Isaac-Renton J, Clark C, Rahn K, Kaper JB. 2003. Association of genomic O island 122 of Escherichia coli EDL 933 with verocytotoxin-producing Escherichia coli seropathotypes that are linked to epidemic and/or serious disease. J. Clin. Microbiol. 41:4930-4940. http://dx.doi .org/10.1128/JCM.41.11.4930-4940.2003.
    • (2003) J. Clin. Microbiol. , vol.41 , pp. 4930-4940
    • Karmali, M.A.1    Mascarenhas, M.2    Shen, S.3    Ziebell, K.4    Johnson, S.5    Reid-Smith, R.6    Isaac-Renton, J.7    Clark, C.8    Rahn, K.9    Kaper, J.B.10
  • 39
    • 79959630553 scopus 로고    scopus 로고
    • Loss of vtx genes after the first subcultivation step of verocytotoxigenic Escherichia coli O157 and non-O157 during isolation from naturally contaminated fecal samples
    • Joris MA, Verstraete K, Reu KD, Zutter LD. 2011. Loss of vtx genes after the first subcultivation step of verocytotoxigenic Escherichia coli O157 and non-O157 during isolation from naturally contaminated fecal samples. Toxins (Basel) 3:672-677. http://dx.doi.org/10.3390/toxins3060672.
    • (2011) Toxins (Basel) , vol.3 , pp. 672-677
    • Joris, M.A.1    Verstraete, K.2    Reu, K.D.3    Zutter, L.D.4
  • 40
    • 34249733688 scopus 로고    scopus 로고
    • Shiga toxin gene loss and transfer in vitro and in vivo during enterohemorrhagic Escherichia coli O26 infection in humans
    • Bielaszewska M, Prager R, Kock R, Mellmann A, Zhang W, Tschape H, Tarr PI, Karch H. 2007. Shiga toxin gene loss and transfer in vitro and in vivo during enterohemorrhagic Escherichia coli O26 infection in humans. Appl. Environ. Microbiol. 73:3144-3150. http://dx.doi.org/10.1128/AEM .02937-06.
    • (2007) Appl. Environ. Microbiol. , vol.73 , pp. 3144-3150
    • Bielaszewska, M.1    Prager, R.2    Kock, R.3    Mellmann, A.4    Zhang, W.5    Tschape, H.6    Tarr, P.I.7    Karch, H.8
  • 41
    • 69449083854 scopus 로고    scopus 로고
    • Pulsed-field gel electrophoresis profile changes resulting from spontaneous chromosomal deletions in enterohemorrhagic Escherichia coli O157:H7 during passage in cattle
    • Yoshii N, Ogura Y, Hayashi T, Ajiro T, Sameshima T, Nakazawa M, Kusumoto M, Iwata T, Akiba M. 2009. Pulsed-field gel electrophoresis profile changes resulting from spontaneous chromosomal deletions in enterohemorrhagic Escherichia coli O157:H7 during passage in cattle. Appl. Environ. Microbiol. 75:5719-5726. http://dx.doi.org/10.1128/AEM .00558-09.
    • (2009) Appl. Environ. Microbiol. , vol.75 , pp. 5719-5726
    • Yoshii, N.1    Ogura, Y.2    Hayashi, T.3    Ajiro, T.4    Sameshima, T.5    Nakazawa, M.6    Kusumoto, M.7    Iwata, T.8    Akiba, M.9


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.