Mycoplasma alkalescens
(Leach, 1973)
Etymology
Gr. n. mukes – fungus, Gr. neut. n. plasma – anything formed, N.L. neut. n. Mycoplasma – fungus form; N.L. v. alkalesco – to make alkaline, N.L. part. adj. alkalescens – alkaline-making
Taxonomy
Mycoplasmatales – Mycoplasmataceae – Mycoplasma – Mycoplasma alkalescens (Hominis cluster), closely related to Mycoplasma auris (16S rRNA gene sequence similarity - 98.97%) (Fig. 1)
Type strain
PG51T (cattle, Australia, 1963), (Fig. 2, 16S rRNA gene sequence)
Genomes
1 completed (PG51T – Australia); 2 draft genomes (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
cattle, occasionally isolated from small ruminants including wild ungulates
Habitat
upper respiratory tract
Disease(s)
increasingly reported as secondary cause calf pneumonia, arthritis, mastitis, and otitis media, predominantly in association with Mycoplasma bovis
Pathogenicity
factors unknown
Epidemiology
worldwide occurrence; transmission modes unknown
Diagnosis
cultivation and species identification by MALDI-ToF MS, serology or genetically; PCR
Fig. 1. Maximum likelihood tree showing the phylogenetic position of Mycoplasma alkalescens PG51T 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)
CTGGCTGTGTGCCTAATACATGCATGTCGAGCGAGGTTTTTTAAACCTAGCGGCGAATGGGTGAGTAACACGTGCTTAATCTACCCTTTAGATTGGAATACCCAATGGAAACATTGGCTAATGCCGGATACGCATAAAATCGCATGATTTTGTTGTGAAAGGAGCCTTTAAAGCTCCACTAGAGGATGAGGGTGCGGAACATTAGTTAGTTGGTAGGGTAATGGCCTACCAAGACTATGATGTTTAGCCGGGTCGAGAGACTGAACGGCCACATTGGGACTGAGATACGGCCCAAACTCCTACGGGAGGCAGCAGTAGGGAATATTCCACAATGAGCGAAAGCTTGATGGAGCGACACAGCGTGCACGATGAAGGTCTTCGGATTGTAAAGTGCTGTTATAGGGAAAGAAAACTTGGTTGAGGAAATGCTTCCAAGCTGACGGTACCCTGTCAGAAAGCGATGGCTAACTATGTGCCAGCAGCCGCGGTAATACATAGGTCGCAAGCGTTATCCGGAATTATTGGGCGTAAAGCGTTTGTAGGCTGTTTATTAAGTCTGGAGTTAAATCCCAGGGCTCAACCCTGGTTCGCTTTGGATACTGGTAAACTAGAGTTGGATAGAGGTAAGCGGAATTCCATGTGAAGCGGTGAAATGCGTAGATATATGGAAGAACACCAAAGGCGAAGGCAGCTTACTGGGTCTATACTGACGCTGAGGGACGAAAGCGTGGGGAGCAAACAGGATTAGATACCCTGGTAGTCCACGCCGTAAACGATGATCATTAGTCGGTGGAGAATTCACTGACGCAGCTAACGCATTAAATGATCCGCCTGAGTAGTATGCTCGCAAGAGTGAAACTTAAAGGAATTGACGGGGACCCGCACAAGCGGTGGAGCATGTGGTTTAATTTGAAGATACGCGGAGAACCTTACCCACTCTTGACATCCTTCGCAAAGCTATAGAGATATAGTCGAGGTTAACGGAGTGACAGATGGTGCATGGTTGTCGTCAGCTCGTGTCGTGAGATGTTTGGTCAAGTCCTGCAACGAGCGCAACCCCTATCTTTAGTTACTAACGAGTCATGTCGAGGACTCTAGAGATACTGCCTGGGTAACTGGGAGGAAGGTGGGGATGACGTCAAATCATCATGCCTCTTACGAGTGGGGCAACACACGTGCTACAATGGTCGGTACAAAGAGAAGCAATATGGCGACATGGAGCAAATCTCAAAAAGCCGATCTCAGTTCGGATTGGAGTCTGCAATTCGACTCCATGAAGTCGGAATCGCTAGTAATCGCAGATCAGCTACGCTGCGGTGAATACGTTCTCGGGTCTTGTACACACCGCCCGTCACACCATGGGAGCTGGTAATACCCGAAGTCGGTTAGCTAACCTCGGAGGCGACCGCCTAAGGTAGGACTGGTGACTGGGGTGAAGTCGTAACAAGGT
Fig. 2. 16S rRNA gene sequence of Mycoplasma alkalescens PG51T (Accession number: NR_025984)
Fig. 3. Colonies of Mycoplasma alkalescens PG51T on modified Hayflick’s agar after 4 days of incubation exhibiting fried egg morphology, a variable colony size, and an alkaline pH (colour change from ochre to red) resulting from arginine hydrolysis. Bar, 1 mm. Credits: Joachim Spergser (Vetmeduni Vienna)