| Haemobartonella felis is a member of a newly defined group of haemotrophic mycoplasmas that parasitize the red blood cells of mammals. The genera Haemobartonella and Eperythrozoon had previously been classified in the order Rickettsiales, family Anaplasmatacae, but new 16S-rRNA sequence data, has firmly established that the Haemobartonellas and Eperythrozoons are closely related to each other, and both are members of the Family Mycoplasmamatales. It has been suggested that H. felis be renamed Mycoplasma haemofelis.; The lack of an adequate diagnostic test for H. felis hampers the identification of infected animals. The 16S-rRNA gene was used to create a polymerase chain reaction diagnostic test for H. felis . This test in conjunction with in situ hybridization experiments provided substantial evidence that H. felis is responsible for the clinical disease historically reported as feline infectious anemia.; Feline infectious anemia is an excellent model for the human haemobartonellosis. Both clinical syndromes are more often seen in immunocompromised hosts who live in warmer climates. This study of the genome organization and molecular pathogenesis of H. felis will aid our understanding of the human haemotrophic bacteria seen in immunocompromised patients.; Little was known about the genome size or structure of the haemotrophic mycoplasmas and studies of pathogenicity, adhesion, and protein production are hampered by the inability to culture H. felis and use more common genetic tools. A renewable source of H. felis DNA in the form of a large insert library was created to study the genome and search for genes related to pathogenicity and survival. The genome size of H. felis was determined to be 1200 kb using pulsed field gel electrophoresis. A bacterial artificial chromosome (BAC) was used to create a large insert library of the H. felis genomic DNA. Using hybridization experiments and fingerprinting analysis, these BACs were ordered into a genomic encyclopedia with a restriction map. The BACs were then sub-cloned into a plasmid to generate high throughput genomic sequencing surveys (GSS) data. These GSSs were compared to the four completed sequenced mycoplasma and deposited in GenBank. This represents the first description of a physical and genomic map of an uncultivable mycoplasma. |
