H. Kleivdal et T. Hofstad, CHROMOSOMAL RESTRICTION-ENDONUCLEASE ANALYSIS AND RIBOTYPING OF BACTEROIDES-FRAGILIS, APMIS. Acta pathologica, microbiologica et immunologica Scandinavica, 103(3), 1995, pp. 180-184
We have analysed the restriction fragment length patterns of chromosom
al DNA and of ribosomal RNA (rRNA) genes in order to investigate the c
lonal distribution within Bacteroides fragilis isolates. Eighteen bloo
d culture isolates from 18 patients and 4 faecal isolates from 4 subje
cts were examined. Chromosomal restriction endonuclease analysis (REA)
was performed by separating BamHI-generated DNA fragments using polya
crylamide gel electrophoresis (PAGE). Ribotyping was accomplished by h
ybridizing EcoRI-treated genomic DNA subjected to conventional REA on
agarose to a radiolabelled probe obtained from 16 + 23S rRNA of E. col
i. All 22 isolates could be differentiated by their REA patterns with
a varying percentage of similar fragments. Analysis of the rRNA gene p
atterns displayed heterogeneity, and revealed 14 ribotypes among the 1
8 blood culture isolates and 3 among the 4 faecal isolates. The predom
inant ribotype among the clinical isolates was also shared by one faec
al isolate. The results suggest that no particular clones are predomin
antly responsible for systemic infection.