VetBact logo


Swedish University of Agricultural Sciences

Veterinary bacteriology: information about important bacteria
Veterinary bacteriology

Species/Subspecies: Mesomycoplasma dispar
Etymology: Genus name: between other mycoplasmas (fungus shaped).
Species epithet: different.
Significance:  [Of minor importance]   
Alternative Species Name(s):Mycoplasma dispar
Type Strain: 462/2 = ATCC 27140 = NTCC 10125
Macromorphology (smell): Forms small and atypical colonies, which are not umbonated (no "fried egg appearance") and should be observed in a microscope.
Micromorphology: The small cells are coccoid or short filamentous.
Gram +/Gram -:G-, but is normally not gram stained because the cells will then be fragmented.
Metabolism: Facultatively anaerobic. M. dispar is a glucose fermenter, which lowers the pH in the growth medium.
Spec. Char.:
Disease:Pneumonia and sometimes mastitis.
HostsDiseaseClinical picture
Cattle (calves)Pneumonia (calf pneumonia)Peribronchiolar lymphoid hyperplasia and purulent bronchiolitis
CattleMastitisReduced milk production
Virulence Factors: Can produce hydrogen peroxide (H2O2) and biofilm.
Genome Sequence:
Acc-noStrainSize (bp)GenomeRef.
CP024161 GS01 1 090 351  Nr 169

16S rRNA Seq.:
Acc-noStrainNumber of NTOperon
AF412979 462/2T 1475  

About 15 species have been described within the genus Mesomycoplasma. Mesomycoplasma dispar is closely related to M. ovipneumoniae, M. hyopneumoniae as well as M. flocculare.

Note that the letter M in the phylogenetic tree (Fig. 230:1) can mean Mycoplasma, Mesomycoplasma, Metamycoplasma, Mycoplasmoides or Mycoplasmopsis.

Comment:Based on whole genome sequencing, the taxonomy of mycoplasmas has recently undergone a comprehensive revision. The new taxonomy has now been introduced in VetBact, but it will still be possible to search for the alternative species names. Read more about the revised taxonomy of the mollicutes under the Term list of VetBact and see also reference 164 below.
Reference(s): No. 164, 168


New names of bacterial phyla

The taxonomic category phylum was previously not regulated by the International Code of Nomenclature of Prokaryotes (ICNP), but now this has changed and it was decided to revise the names of bacterial phyla. All phyla must be written in italics (which has been done on VetBact also before) and have the ending -ota.

Published 2023-03-01. Read more...
The taxonomy of chlamydias

Species within the family Chlamydiaceae were previously divided into two genera Chlamydia and Chlamydophila. However, the differences between these two genera were not that great and many research groups have not accepted this division. Therefore, the genus Chlamydophila has been returned to the genus Chlamydia and this change has now been incorporated in VetBact

Published 2023-03-15. Read more...

Recently Updated

Recent blog posts

Most recent comment

Swedish University of Agricultural Sciences