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EHP003 Characterization of shigatoxin-encoding Escherichia coli (STEC) isolates from pigs in Germany
Wissenschaftliches Programm 55. DGHM-Tagung 29. September-1. Oktober 2003 in Dresden Abstracts - Poster
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members of 16 different species of aerobic and anaerobic bacteria frequently present in stool were negative in the sfpA PCR. This PCR detected as low as 102 SF EHEC O157:H ° genome equivalents. We conclude that sfpA is present in 100% of SF EHEC O157:H-. The PCR with primers complementary to this gene is a highly sensitive and specific method for screening and identification of SF EHEC O157:H-. Therefore, we strongly recommend the introduction of the sfpA PCR, in addition to those detecting stx2, eae and rfbolsz into the screening of stools from children with HUS.
Characterization of Shigatoxin-encoding Escherichia coil (STEC) isolates from pigs in
Germany Barth, S.1; Tscholshiew, A.1; Vallejo, G}, Bauerfeind, R. 1
1Justus-Liebig-Universit~t Giessen; Institut f~r Hygiene und Infektionskrankheiten der Tiere Pigs on breeding and fattening farms in Hessen, Germany, were tested by fecal culture methods and PCR for Escherichia coil bacteria carrying a gene of the shigatoxin 2 type (STEC-2) in order to assess the significance of pigs as reservoir for enterohaemorrhagic E.coli (EHEC). STEC-2 isolates were further characterized by specific PCRs for genes of shigatoxins (stxl/lc, stx2, stx2c, stx2d, stx2e, stx2f), enterotoxins (estb, estap, elt), fimbrial proteins (faeG, fanA, fasA, fedA, fim41a), and intimin (eaeA). Isolates were also tested for hemolysis and O-antigens. STEC-2 (n = 164) were isolated from 141 of 975 pigs (14.5 %) on 52 of 323 farms ( 1 6 . 1 % ) . All isolates proved positive for the stx2e gene and none of them harbored another stx gene. The majority of these isolates (n = 121; 73.2 %) exhibited all typical features of porcine edema disease E.coli because they expressed O-antigens 138 (8.5 %), 139 (17.7 %), or 141 (51.2 %), and possessed the fedA gene coding for the major subunit of F18 fimbria. Additionally, all but one of these isolates caused hemolysis on sheep blood agar plates. The 53 other STEC-2 isolates did either not have a fedA gene (5 isolates) or belonged to other serogroups, e.g. O 147, O 149, O157 (24 isolates), or both (14 isolates). Genes for intimin or F4, F5, F6, or F41 fimbria were not detected in any isolate. However, 89 isolates (54.3 %) carried genes for one or more of the E.coli enterotoxins. Our results suggest that pigs are no important reservoir for highly virulent strains and that most STEC isolates from pigs belong to the pathovar of host species adapted edema disease E.coli (EDEC). However, a considerable number of piglets is infected with strains of Stx2e-encoding E.coli whose pathogenic and zoonotic significance remains to be established.
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421
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members of 16 different species of aerobic and anaerobic bacteria frequently present in stool were negative in the sfpA PCR. This PCR detected as low as 102 SF EHEC O157:H ° genome equivalents. We conclude that sfpA is present in 100% of SF EHEC O157:H-. The PCR with primers complementary to this gene is a highly sensitive and specific method for screening and identification of SF EHEC O157:H-. Therefore, we strongly recommend the introduction of the sfpA PCR, in addition to those detecting stx2, eae and rfbolsz into the screening of stools from children with HUS.
Characterization of Shigatoxin-encoding Escherichia coil (STEC) isolates from pigs in
Germany Barth, S.1; Tscholshiew, A.1; Vallejo, G}, Bauerfeind, R. 1
1Justus-Liebig-Universit~t Giessen; Institut f~r Hygiene und Infektionskrankheiten der Tiere Pigs on breeding and fattening farms in Hessen, Germany, were tested by fecal culture methods and PCR for Escherichia coil bacteria carrying a gene of the shigatoxin 2 type (STEC-2) in order to assess the significance of pigs as reservoir for enterohaemorrhagic E.coli (EHEC). STEC-2 isolates were further characterized by specific PCRs for genes of shigatoxins (stxl/lc, stx2, stx2c, stx2d, stx2e, stx2f), enterotoxins (estb, estap, elt), fimbrial proteins (faeG, fanA, fasA, fedA, fim41a), and intimin (eaeA). Isolates were also tested for hemolysis and O-antigens. STEC-2 (n = 164) were isolated from 141 of 975 pigs (14.5 %) on 52 of 323 farms ( 1 6 . 1 % ) . All isolates proved positive for the stx2e gene and none of them harbored another stx gene. The majority of these isolates (n = 121; 73.2 %) exhibited all typical features of porcine edema disease E.coli because they expressed O-antigens 138 (8.5 %), 139 (17.7 %), or 141 (51.2 %), and possessed the fedA gene coding for the major subunit of F18 fimbria. Additionally, all but one of these isolates caused hemolysis on sheep blood agar plates. The 53 other STEC-2 isolates did either not have a fedA gene (5 isolates) or belonged to other serogroups, e.g. O 147, O 149, O157 (24 isolates), or both (14 isolates). Genes for intimin or F4, F5, F6, or F41 fimbria were not detected in any isolate. However, 89 isolates (54.3 %) carried genes for one or more of the E.coli enterotoxins. Our results suggest that pigs are no important reservoir for highly virulent strains and that most STEC isolates from pigs belong to the pathovar of host species adapted edema disease E.coli (EDEC). However, a considerable number of piglets is infected with strains of Stx2e-encoding E.coli whose pathogenic and zoonotic significance remains to be established.
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421