Molecular Characterisation Of Escherichia Coli Serogroup O 157:H7
Fourteen E. coli O 157:H7 beef isolates were characterised by using four specific epidemiological markers: combination of antibiogram and plasmid profiling, pulsed-field gel electrophoresis (PFGE) and arbitrary primed polymerase chain reaction (AP-PCR). These markers were assessed for their reli...
محفوظ في:
| المؤلف الرئيسي: | |
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| التنسيق: | أطروحة |
| اللغة: | English |
| منشور في: |
1998
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| الموضوعات: | |
| الوصول للمادة أونلاين: | http://psasir.upm.edu.my/id/eprint/8384/1/FSMB_1998_1_A.pdf |
| الوسوم: |
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| الملخص: | Fourteen E. coli O 157:H7 beef isolates were characterised by using
four specific epidemiological markers: combination of antibiogram and
plasmid profiling, pulsed-field gel electrophoresis (PFGE) and arbitrary
primed polymerase chain reaction (AP-PCR). These markers were
assessed for their reliability, typability, rapidity and discriminatory
power in differentiating beef E. coli O 157:H7 strains from different
locations, namely Bangsar, Kajang, Petaling Jaya and Serdang. The
majority of the isolates were resistant to penicillin G (100%), vancomycin
(100%), trimethoprim/ sulphametoxazole (100%), bacitracin ( 1 00%) and
erythromycin (92.8%). Only 21.4% were resistant to carbenicillin. 14.3%
and 7.1% were resistant to ampicillin and cephalotin, respectively Plasmid analysis revealed three basic plasmid patterns among E. coli
O 157:H7 strains, profile 1 characterised by plasmid DNA of 60 and 2.5
MDa, profile 2 characterised by plasmid of 60 MDa, and profile 3
characterised by the absence of any plasmid in the strains. Grouping
according to combination of antibiogram and plasmid analysis indicated
eight different groups as two strains with similar antibiotype could be
distinguished into two different strains by their dissimilar plasmid
profile. However, the reliability of antibiogram and plasmid analysis in
typing E. coli O 157:H7 can be questioned. Thus, other reliable methods
such as PFGE and AP-PCR were then applied. In the present study,
macrorestriction of genomic DNA of E. coli 0 1 57:H7 using Xbal, SpeI and
HindIII and analysed by PFGE successfully grouped ten out of fourteen
isolates into five groups and provided evidence of epidemiologically
related strains between strains of different and same locations. However,
AP-PCR using three short primers grouped the isolates into fourteen
distinct groups and differentiates isolates that were not differentiated by
PFGE. The overall analysis of the present study revealed AP-PCR as the
most suitable method to differentiate E. coli O 157:H7 because it was
more discriminatory, less labor intensive and applicable to all isolates.
Using this method, it was clearly shown that all fourteen E. coli O 157:H7
existed as independent isolates. |
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