396
E. A. FREUNDT ET AL.
I n consequence, it is recommended that only limited importance should be
attached to the results of the biochemical tests and that simultaneously
strains should be tested serologically with antisera against all of the seven
species currently recognised.
There is no basis for a subdivision of the genus Ureaplasma on biochemical activities and serological identification essentially employs the
same methods that are used for Mycoplasma and Acholeplasma (Black,
1970, 1973b; Black and Krogsgaard-Jensen, 1974). Until now, only one
species has been recognised within the genus Ureaplasma, U. urealyticum,
comprising eight serotypes (Shepard et al., 1974). It should be pointed out
here that what are referred to as different “serotypes” of one species of
Ureaplasma would in fact have been designated as distinct species in the
genera Mycoplasma and Acholeplasma (cf. Subcommittee on the Taxonomy
of Mycoplasmatales, 1974). The taxonomic status of the ureaplasmas
isolated from a variety of different animals, and their relationship to U.
urealyticum, remains undefined.
B. Serological testing
This is carried out following selection of the antisera which have been
suggested as appropriate by the preliminary biochemical screening. As will
have appeared from the classification section, there are three methods that
should primarily be considered for serological identification, the growth
inhibition, metabolism inhibition, and immunofluorescence tests. Up to
the present most identifications have probably been performed by means
of the growth inhibition and metabolism inhibition tests although unfortunately the former is not sufficiently sensitive and the latter is timeconsuming and relatively difficult to perform. The indirect immunofluorescence test approaches the ideal test method, since both specificity
and sensitivity are at an adequate level, and it is technically simple when
the necessary equipment is at hand.
T o summarise, the identification procedure is initiated with the digitonin
test, followed by the urease test if the organism proves digitonin-sensitive.
Under special circumstances, when the occurrence of a spiroplasma is
suspected, a morphological examination should also be carried out. Strains
shown to belong to the genus Mycoplasma are then tested for glucose
fermentation, arginine hydrolysis, phosphatase activity, and possibly serum
digestion as a preliminary to the final serological identification. This is
most easily performed by the indirect immunofluorescence test, but may
be carried out by means of growth inhibition, metabolism inhibition and,
in special cases, complement fixation, double immunodiffusion or possibly
direct agglutination tests.
E. A. FREUNDT ET AL.
I n consequence, it is recommended that only limited importance should be
attached to the results of the biochemical tests and that simultaneously
strains should be tested serologically with antisera against all of the seven
species currently recognised.
There is no basis for a subdivision of the genus Ureaplasma on biochemical activities and serological identification essentially employs the
same methods that are used for Mycoplasma and Acholeplasma (Black,
1970, 1973b; Black and Krogsgaard-Jensen, 1974). Until now, only one
species has been recognised within the genus Ureaplasma, U. urealyticum,
comprising eight serotypes (Shepard et al., 1974). It should be pointed out
here that what are referred to as different “serotypes” of one species of
Ureaplasma would in fact have been designated as distinct species in the
genera Mycoplasma and Acholeplasma (cf. Subcommittee on the Taxonomy
of Mycoplasmatales, 1974). The taxonomic status of the ureaplasmas
isolated from a variety of different animals, and their relationship to U.
urealyticum, remains undefined.
B. Serological testing
This is carried out following selection of the antisera which have been
suggested as appropriate by the preliminary biochemical screening. As will
have appeared from the classification section, there are three methods that
should primarily be considered for serological identification, the growth
inhibition, metabolism inhibition, and immunofluorescence tests. Up to
the present most identifications have probably been performed by means
of the growth inhibition and metabolism inhibition tests although unfortunately the former is not sufficiently sensitive and the latter is timeconsuming and relatively difficult to perform. The indirect immunofluorescence test approaches the ideal test method, since both specificity
and sensitivity are at an adequate level, and it is technically simple when
the necessary equipment is at hand.
T o summarise, the identification procedure is initiated with the digitonin
test, followed by the urease test if the organism proves digitonin-sensitive.
Under special circumstances, when the occurrence of a spiroplasma is
suspected, a morphological examination should also be carried out. Strains
shown to belong to the genus Mycoplasma are then tested for glucose
fermentation, arginine hydrolysis, phosphatase activity, and possibly serum
digestion as a preliminary to the final serological identification. This is
most easily performed by the indirect immunofluorescence test, but may
be carried out by means of growth inhibition, metabolism inhibition and,
in special cases, complement fixation, double immunodiffusion or possibly
direct agglutination tests.