Objective—To determine whether Haemobartonella
canis and Mycoplasma haemofelis (formerly known
as H felis [large form]) can be differentiated by use of
comparative analysis of gene sequences.
Sample Population—Blood samples obtained from
3 dogs infected with H canis and 2 cats infected with
Procedure—The partial 16S rDNA and ribonuclease P
RNA (RNase P) genes were amplified, cloned, and
sequenced in blood samples obtained from H canis-infected
dogs and M haemofelis-infected cats. The
DNA sequences were subjected to comparative
Results—The 16S rDNA sequences of H canis and M
haemofelis were nearly identical (homology of 99.3 to
99.7%). In contrast, RNase P gene sequences had a
lower degree of sequence homology between the 2
organisms (94.3 to 95.5%).
Conclusions and Clinical Relevance—Haemobartonella
canis and M haemofelis are not identical
organisms. Molecular differentiation of H canis and M
haemofelis is more clearly evident by use of comparative
analysis of RNase P gene sequences than by
comparative analysis of 16S rDNA gene sequences.
(Am J Vet Res 2002;63:1385–1388)