Mycoplasma phocidae
(Ruhnke & Madoff, 1992)
Etymology
Gr. n. mukes – fungus, Gr. neut. n. plasma – anything formed, N.L. neut. n. Mycoplasma – fungus form; L. n. phoca – a seal, N.L. gen. n. phocidae (sic) – of a seal
Taxonomy
Mycoplasmatales – Mycoplasmataceae – Mycoplasma – Mycoplasma phocidae (Hominis cluster), related to Mycoplasma equirhinis (16S rRNA gene sequence similarity – 96.90%) (Fig. 1)
Type strain
105T (harbor seal – Phoca vitulina, USA, 1979-1980), (Fig. 2, 16S rRNA gene sequence)
Genomes
one completed genome (105T – 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
pinnipeds including harbor seal, grey seal, common seal, and Australian fur seal
Habitat
respiratory tract
Disease(s)
considered to be a secondary pathogen potentially causing aggravation of respiratory disease in association with other diseases (e.g. viral infection) or environmental factors, also consistently found in wound infections, has frequently been associated with seal finger resulting from seal bites in humans
Pathogenicity
factors largely unknown, candidate virulence factors include a family of putative surface antigens with amino acids similar to pneumococcal complement evasion protein PspA, protein M which binds to host IgG to block antigen-specific binding, and a IgG heavy chain-binding protein similar to IgG endoprotease IdeP of Streptococcus phocae fused to mycoplasma lipoprotein LppA, all probably involved in immunosuppression and immune evasion
Epidemiology
has been isolated from pinnipeds in the USA, Canada, UK, and Australia
Diagnosis
cultivation and species identification by MALDI-ToF MS, serology or genetically
Fig. 1. Maximum likelihood tree showing the phylogenetic position of Mycoplasma phocidae 105T 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)
CTGGCTGTGTGCCTAATACATGCATGTCGAGCGAGGTTCTTATTAGAACCTAGCGGCGAATGGGTGAGTAACACGTACTTAATCTGCCCTTTAGATTGGAATACCCAATGGAAACATTGGCTAATGCCGGATACGCATAGAATCGCATGATTCTGTTGTGAAAGGAGCTCCAAAGCTCCACTAAAGGATGAGGGTGCGGAACATTAGTTAGTTGGTGAGGTAATGGCCCACCAAGACTATGATGTTTAGCCGGGTCGAGAGACTGAACGGCCACATTGGGACTGAGATACGGCCCAAACTCCTACGGGAGGCAGCAGTAGGGAATATTCCACAATGAGCGAAAGCTTGATGGAGCGACACAGCGTGCACGATGAAGGTCTTCGGATTGTAAAGTGCTGTTATAAGGGAAGAACACTCAGTAGAGGAAATGCTATTGAGCTGACGGTACCTTGTCAGAAAGCGATGGCTAACTATGTGCCAGCAGCCGCGGTAATACATAGGTCGCAAGCGTTATCCGGAATTATTGGGCGTAAAGCGTTCGTAGGCTGTTTGTTAAGTCTAGAGTCAAATTCCAGGGCTCAACCCTGGCTCGCTTTGGATACTGGCAAACTAGAGTTAGATAGAGGTAAGCGGAATTCCATGTGAAGCGGTGAAATGCGTAGATATATGGAAGAACACCAAAGGCGAAGGCAGCTTACTGGGTCTATACTGACGCTGAGGGACGAAAGCGTGGGGAGCAAACAGGATTAGATACCCTGGTAGTCCACGCTGTAAACGATGATCATTAGTCGGTGGAGGAATCACTGACGCAGCTAACGCATTAAATGATCCGCCTGAGTAGTATGCTCGCAAGAGTGAAACTTAAAGGAATTGACGGGGACCCGCACAAGCGGTGGAGCATGTGGTTTAATTTGAAGATACACGGAAAACCTTACCCACTTTTGACATCCTTCGCGAAGCTATAGAGATATAGTGGAGGCTAACGGAGTGACAGATGGTGCATGGTTGTCGTCAGCTCGTGTCGTGAGATGTTTGGTCAAGTCCTGCAACGAGCGCAACCCCTATCTTTAGTTACTAACAAGTAATGTTGAGGACTCTAGAGATACTGCCTGGGTAACTGGGAGGAAGGTGGGGATGACGTCAAATCATCATGCCTCTTACAAGTGGGGCCACACACGTGCTACAATGGGCGGTACAAAGAGAAGCAATATGGCGACATGGAGCAAATCTCAAAAAGCCGATCTCAGTTCGGATTGGAGTCTGCAATTCGACTCCATGAAGTCGGAATCGCTAGTAATCGCAGATCAGCTATGCTGCGGTGAATACGTTCTCGGGTCTTGTACACACCGCCCGTCACACCATGGGAGCTGGTAATACCCAAAGTCGGTTTGCTAACCTCGGAGGCAACTGCCTAAGGTAGGACTGGTGACTGGGGTGAAGTCGTAACAAGGT
Fig. 2. 16S rRNA gene sequence of Mycoplasma phocidae 105T (Accession number: NR_025135)
Fig. 3. Colonies of Mycoplasma phocidae 105T 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)