Mycoplasma arthritidis
(Sabin, 1941; Freundt, 1955)
Etymology
Gr. n. mukes – fungus, Gr. neut. n. plasma – anything formed, N.L. neut. n. Mycoplasma – fungus form; Gr. n. arthritis – arthritis, N.L. gen. n. arthritidis – of arthritis
Taxonomy
Mycoplasmatales – Mycoplasmataceae – Mycoplasma – Mycoplasma arthritidis (Hominis cluster), closely related to Mycoplasma buccale (16S rRNA gene sequence similarity – 97.50%) (Fig. 1)
Type strain
PG6T (rat, USA, 1942), (Fig. 2, 16S rRNA gene sequence)
Genomes
2 completed (PG6T – USA; 158L3-1 – USA) (NCBI Genome deposit per 11/05/2024)
Cell morphology
spherical – coccoid
Colony morphology
fried egg morphology (Fig. 3)
Metabolism
hydrolysis of arginine; non-fermentative, non-urea-hydrolyzing
Host
rats, mice
Habitat
upper respiratory tract
Disease(s)
mostly subclinical infections, occasionally arthritis
Pathogenicity
a mitogen with superantigen activity (MAM) has been proposed as major virulence factor, further factors include size and phase variable surface lipoproteins with roles in adhesion and immune evasion
Epidemiology
rare but worldwide occurrence; transmission by direct contact or aerosol
Diagnosis
cultivation and species identification by MALDI-ToF MS, serology or genetically; PCR; detection of antibodies using immunoassays
Fig. 1. Maximum likelihood tree showing the phylogenetic position of Mycoplasma arthritidis PG6T within the Hominis cluster of Mycoplasmataceae based on 16S rRNA gene sequences. The sequence of Mycoplasma synoviae WVU 1853T was used as out-group (Synoviae cluster). Numbers at nodes represent bootstrap confidence values (1000 replications). Only values > 80% are shown. Bar, number of substitutions per nucleotide position. Credits: Joachim Spergser (Vetmeduni Vienna)
CTGGCTGTGTGCCTAATACATGCATGTCGAGCGGAAGTAGCAATACTTTAGCGGCGAATGGGTGAGTAACACGTGCTTAATCTACCCTTTAGACTGGAATAACTAATGGAAACATTGGCTAATGCCGGATGCGCATGGAATCGCATGATTCCGTTGTGAAAGGAGCCTCAAAGCTCCACTAGAGGATGAGGGTGCGGAACATTAGCTTGTTGGTGAGGTAACGGCCCACCAAGGCAATGATGTTTAGCCGGGTCGAGAGACTGAACGGCCACATTGGGACTGAGATACGGCCCAAACTCCTACGGGAGGCAGCAGTAGGGAATATTCCACAATGAGCGAAAGCTTGATGGAGCGACACAGCGTGCACGATGACGGTCTTCGGATTGTAAAGTGCTGTTATAGGGGAAGAACACTTAGTTGAGGAAATGCTTCTAAGCTGACGGTACCCTGTCAGAAAGCGATGGCTAACTATGTGCCAGCAGCCGCGGTAATACATAGGTCGCAAGCGTTATCCGGAATTATTGGGCGTAAAGCGTTCGTAGGCTGTTTATTAAGTCTGGAGTTAAATCCCAGGGCTCAACCCTGGCTCGCTTTGGATACTGGTAAACTAGAGTTAGATAGAGGTAAGCGGAATTCCATGTGAAGCGGTGAAATGCGTAGATATATGGAAGAACACCAAAGGCGAAGGCAGCTTGCTGGGTCTATACTGACGCTGAGGGACGAAAGCGTGGGGAGCAAACAGGATTAGATACCCTGGTAGTCCACGCCGTAAACGATGATCATTAGTCGGTGGATTAATCACTGACGCAGCTAACGCATTAAATGATCCGCCTGAGTAGTATGCTCGCAAGAGTGAAACTTAAAGGAATTGACGGGGACCCGCACAAGCGGTGGAGCATGTGGTTTAATTTGAAGATACGCGGAGAACCTTACCCACTCTTGACATCCTTCGCAAAGCTATAGAGATATAGTGGAGGTTAACGGAGTGACAGATGGTGCATGGTTGTCGTCAGCTCGTGTCGTGAGATGTTTGGTCAAGTCCTGCAACGAGCGCAACCCCTATCTTTAGTTACTAACGAGTCATGTCGAGGACTCTAGAGATACTGCCTGGGTAACTGGGAGGAAGGTGGGGATGACGTCAAATCATCATGCCTCTTACGAGTGGGGCAACACACGTGCTACAATGGTCGGTACAAAGAGAAGCAATATGGCGACATGGAGCAAATCTCAAAAAGCCGATCTCAGTTCGGATTGGAGTCTGCAATTCGACTCCATGAAGTCGGAATCGCTAGTAATCGCAGATCAGCTATGCTGCGGTGAATACGTTCTCGGGTCTTGTACACACCGCCCGTCACACCATGGGAGCTGGTAATACCCAAAGTCGGTTTGCTAACCTCGGAGGCGACTGCCTAAGGTAGGACTGGTGACTGGGGTGAAGTCGTAACAAGGT
Fig. 2. 16S rRNA gene sequence of Mycoplasma arthritidis PG6T (Accession number: NR_044673)
Fig. 3. Colonies of Mycoplasma arthritidis PG6T on modified Hayflick’s agar after 4 days of incubation exhibiting fried egg morphology. Note, colour change of solid medium from ochre to reddish based on release of ammonia resulting from hydrolysis of arginine creating an alkaline pH. Bar, 1 mm. Credits: Joachim Spergser (Vetmeduni Vienna)