Corynebacterium ulcerans and Corynebacterium pseudotuberculosis responses to DNA probes derived from corynephage beta and Corynebacterium diphtheriae

Abstract

Strains of Corynebacterium ulcerans and Corynebacterium pseudotuberculosis (Corynebacterium ovis) were examined for the production of diphtheria toxin. A majority of C. ulcerans strains (25 of 37) and 1 C. pseudotuberculosis strain (1 of 14) gave a positive Elek test for diphtheria toxin, and for all strains but 1, production of diphtheria toxin was inhibited at the same level of Fe2' as was the Corynebacterium diphtheriae control. All Elek-positive cultures as well as two Elek-negative isolates of C. ulcerans gave a positive signal when hybridized with a DNA probe unambiguous for the diphtheria toxin gene (tox) under conditions of high stringency. The majority of probe-positive C. ulcerans strains contained three or more DNA restriction fragments that hybridized with converting corynephage II, suggesting that in C. ulcerans as in C. diphtheriae there may be a relationship between toxinogeny and carriage of I-related phage. Selected strains of C. diphtheriae, C. ulcerans, and C. pseudotuberculosis were examined for DNA homology by a semiquantitative technique. There was very little homology between C. diphtheriae and members of the other two species. Strains of C. ulcerans and C. pseudotuberculosis, although more closely related, appeared to belong to distinct species as well.

Phylogenetic Positions and Assignment of Swine and Ovine Corynebacterial Isolates Based on the 16S rDNA Sequence

“…However, the 16S rDNA sequence of the swine isolate was completely identical to those of the ovine strains. Furthermore, the close relationship between C. pseudotuberculosis and C. ulcerans confirmed in this study is also supported by their similar biochemical properties and by the results of a DNA/DNA hybridization study (13).…”

Cloning and expression of the phospholipase D gene from Corynebacterium pseudotuberculosis in Escherichia coli

“…Most isolates from horses reduce nitrate (94%) and are streptomycin susceptible (biovar equi), while those from sheep and goats fail to reduce nitrate (97%) and are streptomycin resistant (biovar ovis). Restriction endonuclease analysis of the DNA of these groups has identified differences between isolates from biovars ovis and equi (12,29), but the phenotypic and genotypic bases for the differential host preference have not been defined.…”

INFECTION DUE TO “CORYNEBACTERIUM ULCERANS”, PRODUCING DIPHTHERIA TOXIN

“…Gilbert & Stewart (4) who isolated the bacteria from human throat lesions. "C. u1cerans"is not on the "Approved Lists of Bacterial Names", but it appears from recent DNA homology studies (5) that it is distinct from C. diphtheriae and C. pseudotuberculosis. Like these organisms, "C. ulcerans"is able to produce diphtheria toxin, probably due to carriage of P-related phage.…”