Mycoplasma gallisepticum
(Edward & Kanarek, 1960)
Etymology
Gr. n. mukes – fungus, Gr. neut. n. plasma – anything formed, N.L. neut. n. Mycoplasma – fungus form; L. n. gallus – chicken, L. adj. septicum – septic, N.L. neut. adj. gallisepticum – infecting chicken
Taxonomy
Mycoplasmatales – Mycoplasmataceae – Mycoplasma – Mycoplasma gallisepticum (Pneumoniae cluster), closely related to Mycoplasma imitans and Mycoplasma tullyi (16S rRNA gene sequence similarity – both 99.72%) (Fig. 1)
Type strain
PG31T (chicken, UK, ≤1960), (Fig. 2, 16S rRNA gene sequence)
Genomes
22 completed (PG31T – UK; R(low) – USA; R(high) – USA; 6/85 vaccine strain – unknown; S6 - unknown; F original strain - unknown; F99 lab strain - unknown; F99 Avipro vaccine strain - unknown; ts11 vaccine strain – Australia; mx-4 – USA; 8 x house finch associated strains NC96_1596-4-2P, NC95_13295-2-2P, NC06_2006.080-5-2P, NC08_2008.031-4-3P, WI01_2001.043-13-2P, VA94_7994-1-7P, NY01_2001.047-5-1P, CA06_2006.052-5-2P – all USA; KUVMG001 – South Korea; K5234 – USA; two strains isolated from turkey K4421a, K4043 – USA); 9 draft genomes (NCBI Genome deposit per 17/04/2022)
Cell morphology
flask-shaped
Colony morphology
fried egg morphology (Fig. 3)
Metabolism
fermentation of glucose; assimilation of glycerol; non-arginine-hydrolyzing, non-urea-hydrolyzing
Host
chicken, turkey, wild birds including pheasants, partridges, peacocks, quails, and finches
Habitat
respiratory tract, eye, reproductive tract
Disease(s)
chronic respiratory disease (CRD) of chicken, infectious sinusitis of turkey, conjunctivitis of wild songbirds (finches)
Pathogenicity
based on cytadherence (GapA, CrmA, MGC2, PvpA, OsmC-like protein MG1142, PlpA, Hlp 3, glyceraldehyde-3-phosphate dehydrogenase, enolase, triosephosphate isomerase, pyruvate kinase, pyruvate dehydrogenase), motility, sialidase activity, peroxide production, immune evasion (variable lipoprotein and hemagglutinin gene family vlhA), survival and persistence (MalF, mslA, oppD, Lpd), and biofilm formation
Epidemiology
worldwide occurrence in poultry (chicken, turkey), prevalent in wild birds (finches) in North America and less prevalent in songbirds in Europe and Asia; transmission horizontally by direct or indirect contact, mostly by aerosol, egg transmission is also common
Diagnosis
cultivation and species identification by MALDI-ToF MS, serology or genetically; PCR; detection of antibodies using immunoassays (rapid plate agglutination test, ELISA)
Fig. 1. Maximum likelihood tree showing the phylogenetic position of Mycoplasma gallisepticum PG31T within the Pneumoniae 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)
CTGGCGGCATGCCTAATACATGCAAGTCGATCGGATGTAGCAATACATTAGAGGCGAACGGGTGAGTAACACGTATCCAATCTGCCTTATAGTGGGGGATAACTAGTCGAAAGATTAGCTAATACCGCATAACAAGTTAACTATCGCATGAGAATAACTTTAAAGAAGCAACTGCTTCGCTATAAGATGAGGGTGCGGCATATCAGCTAGTTGGTGAGGGTAATGGCCCACCAAGGCGATGACGTGTAGTTATGCTGAGAGGTAGAATAACCACAATGGGACTGAGACACGGCCCATACTCCTACGGGAGGCAGCAGTAGGGAATTTTTCACAATGGACGAAAGTCTGATGGAGCAATGCCGCGTGAACGATGAAGGTCTTTTTAGATTGTAAAGTTCTTTTATTTGGGAAGAACAGTTAATAGAGTGGAAAGCTATTAATTTGACTGTACCATTTGAATAAGTAACGACTAACTATGTGCCAGCAGTCGCGGTAATACATAGGTTGCAAGCGTTATCCGGATTTATTGGGCGTAAAACAAGCGCAGGCGGATTAGAAAGTCTGGTGTTAAAAGCAATTGCTTAACGATTGTATGCATTGGAAACTTCTAGTCTAGAGTTTGGTAGAGAGTCCTGGAACTCCATGTGGAGCGGTGAAATGCGTAGATATATGGAAGAACACCAGAGGCGAAGGCGAGGACTTGGGCCAATACTGACGCTTAGGCTTGAAAGTGTGGGGAGCAAATAGGATTAGATACCCTAGTAGTCCACACTGTAAACGATGGATGTTAAGTGTCGGAGCGAATACTTCGGTGCTGCAGTTAACACATTAAACATCCTGCCTGAGTAGTACATTCGCAAGAATGAAACTCAAACGGAATTGACGGGGACCCGCACAAGTGGTGGAGCATGTTGCTTAATTCGACGGTACACGAAAAACCTTACCTAGACTTGACATCTTGGGCGAAGCTATAGAAATATAGTGGAGGTCAACCCAATGACAGGTGGTGCATGGTTGTCGTCAGCTCGTGTCGTGAGATGTTGGGTTAAGTCCCGCAACGAGCGCAACCCTTATCGTTAGTTACTTTGTCTGACGAGACTGCCAACGTAAGTTGGAGGAAGGTGGGGATGACGTCAAATCATCATGCCCCTTATGTCTAGGGCTGCAAACGTGCTACAATGGCCAATACAAACAGTTGCAAATCCGTAAGGTGGAGCTAATCTGTAAAGTTGGTCTCAGTTCGGATTGAGGGCTGCAATTCGCCCTCATGAAGTCGGAATCACTAGTAATCGCGAATCAGCCATGTCGCGGTGAATACGTTCTCGGGTCTTGTACACACCGCCCGTCAAACTATGAGAGCTGGTAATATCTAAAACCGTGTTGCTAACCGCAAGGAAGCGCATGTCTAGGGTAGGGCCGGTGATTGGAGTTAAGTCGTAACAAGGT
Fig. 2. 16S rRNA gene sequence of Mycoplasma gallisepticum PG31T (Accession number: NR_104952)
Fig. 3. Colonies of Mycoplasma gallisepticum PG31T on modified Hayflick’s agar after 5 days of incubation exhibiting fried egg morphology. Bar, 1 mm. Credits: Joachim Spergser (Vetmeduni Vienna)