118
A. SARAGEA E7‘ AL.
identical with that elicited in C. diphtheriae, which, as in C. diphtheriae,
may or may not be present in different strains.
2. History
First isolated from the nasopharynx of a group of individuals and considered as “diphtheroid” by Gilbert and Stewart (1926) and Wilson and
Miles (1946), it was called by the authors by its present name, C. ulcerans.
Mair in 1928 reported anomalous results in neutralisation experiments
with diphtheria antitoxin, in guinea pigs and Barratt (1933) found that it
fermented starch and liquefied gelatin. Petrie and McClean (1934) showed
that it may produce two kinds of toxin, one immunologically identical
to diphtherial toxin and its own toxin related to the toxin of C. ovis. Jebb
(1948), Saxholm (1951) and Cook and Jebb (1952), compared a series of
strains isolated from acute tonsillitis, healthy carriers, or skin lesions. The
latter authors suggested some more rapid enzymic reactions (hydrolysis
of urea, and nitrate reduction in routine examination) to differentiate
them from C. diphtheriae graais.
Maximescu (1967), studying reference and wild C. ulcerans strains
isolated from healthy human carriers in Romania, developed a complete
routine scheme for their bacteriological diagnosis. Maximescu (1968), in
an attempt to elucidate the taxonomic position of C. ulcerans, showed
that it has characters in common with C. diphtheriae and C. ovis, sharing
cystinase, ability to ferment carbohydrates, sensitivity to diphtheria
phages and, in spite of major differences in pathogenicity, the capacity
to induce diphtherial toxin biosynthesis in all three species by lysogenisation with a diphtherial tox+ bacteriophage.
The pathogenicity differential test with C. ovis in mice was established
by the same authors (Maximescu et al., 1968, 1974a, b). C. ovis kills mice
by any route of inoculation, while C. ulcerans strains only cause arthritis.
3. Habitat
Both in human cases of acute tonsillitis or healthy carriers and in
animals (horses or cows) producing ulcerative lesions or healthy carriers.
4. Microbiological characters
(a) Morphology. Gram-stained smears prepared from overnight cultures on
Loeffler slants (Fig. 25) show very characteristic features, i.e. a mixture of
pleomorphic club-shaped granular, thin, slightly curved, diphtheria-like
bacilli, and pleomorphic, minute cocci, with a great tendency to overdecolourise, as in C. diphtheriae. Smears sometimes present only pleo-
A. SARAGEA E7‘ AL.
identical with that elicited in C. diphtheriae, which, as in C. diphtheriae,
may or may not be present in different strains.
2. History
First isolated from the nasopharynx of a group of individuals and considered as “diphtheroid” by Gilbert and Stewart (1926) and Wilson and
Miles (1946), it was called by the authors by its present name, C. ulcerans.
Mair in 1928 reported anomalous results in neutralisation experiments
with diphtheria antitoxin, in guinea pigs and Barratt (1933) found that it
fermented starch and liquefied gelatin. Petrie and McClean (1934) showed
that it may produce two kinds of toxin, one immunologically identical
to diphtherial toxin and its own toxin related to the toxin of C. ovis. Jebb
(1948), Saxholm (1951) and Cook and Jebb (1952), compared a series of
strains isolated from acute tonsillitis, healthy carriers, or skin lesions. The
latter authors suggested some more rapid enzymic reactions (hydrolysis
of urea, and nitrate reduction in routine examination) to differentiate
them from C. diphtheriae graais.
Maximescu (1967), studying reference and wild C. ulcerans strains
isolated from healthy human carriers in Romania, developed a complete
routine scheme for their bacteriological diagnosis. Maximescu (1968), in
an attempt to elucidate the taxonomic position of C. ulcerans, showed
that it has characters in common with C. diphtheriae and C. ovis, sharing
cystinase, ability to ferment carbohydrates, sensitivity to diphtheria
phages and, in spite of major differences in pathogenicity, the capacity
to induce diphtherial toxin biosynthesis in all three species by lysogenisation with a diphtherial tox+ bacteriophage.
The pathogenicity differential test with C. ovis in mice was established
by the same authors (Maximescu et al., 1968, 1974a, b). C. ovis kills mice
by any route of inoculation, while C. ulcerans strains only cause arthritis.
3. Habitat
Both in human cases of acute tonsillitis or healthy carriers and in
animals (horses or cows) producing ulcerative lesions or healthy carriers.
4. Microbiological characters
(a) Morphology. Gram-stained smears prepared from overnight cultures on
Loeffler slants (Fig. 25) show very characteristic features, i.e. a mixture of
pleomorphic club-shaped granular, thin, slightly curved, diphtheria-like
bacilli, and pleomorphic, minute cocci, with a great tendency to overdecolourise, as in C. diphtheriae. Smears sometimes present only pleo-