IX. IDENTIFICATION OF MYCOPLASMAS
391
In Table I11 are tabulated the corresponding data for the genus Acholeplasma. The results of the aesculin and arbutin tests are recorded specifically for this genus because these tests appear to be of some use for the
identification of species of this taxon.
111. IDENTIFICATION
AN OUTLINE AND DISCUSSION OF STANDARD PROCEDURES
It follows from the consideration of the general principles of mycoplasma classification presented in the previous Section, that identification
procedures usually include biochemical as well as serological methods, and
that final identification has to be based on serology. Because of the fairly
large and constantly growing number of known mycoplasma species, the
battery of test sera to be used must necessarily be reduced as much as
possible. The results obtained by a preliminary determination of distinguishing biochemical characters will in itself provide a guideline for a
rational selection of the test sera needed. Informition about the source of
the isolate may further reduce the number of test sera that are required for
a first attempt at identification. If, for example, the isolation is made from
the genital tract of a bull, the origin of the strain and the result of the
digitonin test may together imply that testing with a single antiserum will
provide the diagnosis. This is because the two species M . bovigenitalium and
A. laidlawii comprise a high percentage of the mycoplasma flora of the
genital tract of bulls. In effect, knowing from which host the strain derives
will by itself provide a useful indication as to which species should be
looked for first. Although it should be remembered here that the host
specificity of mycoplasmas is less rigid than hitherto believed (Freundt,
1974a). The task is more difficult when the strain to be identified is recovered from a cell culture where possible sources of contamination are
numerous. The outline given below of the standard identification procedure
currently adhered to by the FAO/WHO Collaborating Centre for Animal
Mycoplasmas takes into consideration in the first instance the situation
which exists when no information is available about the origin of
the test strain. The number of tests required to achieve the final identification may then be reduced according to the amount of information about
the origin or source of the strain and its biological properties.
Prior to any detailed examination, the strain is subjected to a simplified
cloning procedure. An isolated colony on solid medium is picked by
suction with a Pasteur pipette. The agar plug with the colony is transferred
to 1.7 ml of broth and crushed against the wall of the test-tube. The culture
is incubated at 3’7°C for four days and used as a stock culture for an
391
In Table I11 are tabulated the corresponding data for the genus Acholeplasma. The results of the aesculin and arbutin tests are recorded specifically for this genus because these tests appear to be of some use for the
identification of species of this taxon.
111. IDENTIFICATION
AN OUTLINE AND DISCUSSION OF STANDARD PROCEDURES
It follows from the consideration of the general principles of mycoplasma classification presented in the previous Section, that identification
procedures usually include biochemical as well as serological methods, and
that final identification has to be based on serology. Because of the fairly
large and constantly growing number of known mycoplasma species, the
battery of test sera to be used must necessarily be reduced as much as
possible. The results obtained by a preliminary determination of distinguishing biochemical characters will in itself provide a guideline for a
rational selection of the test sera needed. Informition about the source of
the isolate may further reduce the number of test sera that are required for
a first attempt at identification. If, for example, the isolation is made from
the genital tract of a bull, the origin of the strain and the result of the
digitonin test may together imply that testing with a single antiserum will
provide the diagnosis. This is because the two species M . bovigenitalium and
A. laidlawii comprise a high percentage of the mycoplasma flora of the
genital tract of bulls. In effect, knowing from which host the strain derives
will by itself provide a useful indication as to which species should be
looked for first. Although it should be remembered here that the host
specificity of mycoplasmas is less rigid than hitherto believed (Freundt,
1974a). The task is more difficult when the strain to be identified is recovered from a cell culture where possible sources of contamination are
numerous. The outline given below of the standard identification procedure
currently adhered to by the FAO/WHO Collaborating Centre for Animal
Mycoplasmas takes into consideration in the first instance the situation
which exists when no information is available about the origin of
the test strain. The number of tests required to achieve the final identification may then be reduced according to the amount of information about
the origin or source of the strain and its biological properties.
Prior to any detailed examination, the strain is subjected to a simplified
cloning procedure. An isolated colony on solid medium is picked by
suction with a Pasteur pipette. The agar plug with the colony is transferred
to 1.7 ml of broth and crushed against the wall of the test-tube. The culture
is incubated at 3’7°C for four days and used as a stock culture for an