RESUMEN
In the search for mollicutes in wild birds, six Mycoplasma strains were isolated from tracheal swabs taken from four different species of seabirds. Four strains originated from three Yellow-legged gulls (Larus michahellis) and a Cory's shearwater (Calonectris borealis) from Spain, one from a South African Kelp gull (Larus dominicanus), and one from an Italian Black-headed gull (Chroicocephalus ridibundus). These Mycoplasma strains presented 99 % 16S rRNA gene sequence similarity values with Mycoplasma (M.) gallisepticum. Phylogenetic analyses of marker genes (16S rRNA gene and rpoB) confirmed the close relationship of the strains to M. gallisepticum and M. tullyi. The seabirds' strains grew well in modified Hayflick medium, and colonies showed typical fried egg morphology. They produced acid from glucose and mannose but did not hydrolyze arginine or urea. Transmission electron microscopy revealed a cell morphology characteristic of mycoplasmas, presenting spherical to flask-shaped cells with an attachment organelle. Gliding motility was also observed. Furthermore, serological tests, MALDI-ToF mass spectrometry and genomic studies demonstrated that the strains were different to any known Mycoplasma species, for which the name Mycoplasma bradburyae sp. nov. is proposed; the type strain is T158T (DSM 110708 = NCTC 14398).
Asunto(s)
Mycoplasma , Animales , Tráquea , Filogenia , ARN Ribosómico 16S/genética , Aves , ADN Bacteriano/genética , Análisis de Secuencia de ADNRESUMEN
Conjunctivitis in swine is a common finding, usually considered to be a secondary symptom of respiratory or viral systemic disease, or a result of irritation by dust or ammonia, or of local infections with Mycoplasma (M.) hyorhinis or chlamydia. In three unrelated swine farms in Germany with a high prevalence of conjunctivitis, a novel mycoplasma species, tentatively named Mycoplasma sp. 1654_15, was isolated from conjunctival swabs taken from affected pigs. Although 16S rRNA gene sequences shared highest nucleotide similarities with M. hyorhinis, matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry, partial rpoB sequencing, and comparative whole genome analyses indicated the identification of a novel species within genus Mycoplasma. Noticeable differences between Mycoplasma sp. 1654_15 and M. hyorhinis were the lack of a vlp locus and the presence of a myo-inositol pathway in the genome of strain 1654_15. Since myo-inositol might be used as an alternative energy source by this pathogen on the conjunctival surface, robust colonization by outcompeting other bacteria could be the consequence. In summary, abundant isolation of Mycoplasma sp. 1654_15 from the conjunctiva of affected pigs, its close relationship to M. hyorhinis, and identification of a panel of coding sequences (CDSs) potentially associated with virulence and pathogenicity suggested a local eye disease caused by a so far unknown, highly specialized mycoplasma species.
RESUMEN
Two moderately halophilic and psychrotolerant new Mycoplasma species were isolated from common cephalopods. Three strains were isolated in pure culture from two individual European flying squid (Todarodes sagittatus), and two individual octopuses (Octopus vulgaris). The strains showed optimal growth at 25 °C and a salinity of 3% (w/v) NaCl. Molecular analyses revealed that the isolates belonged to two new, but phylogenetically related species, divergent from all previously described Mollicutes, representing the first marine isolates of the class, and also the first Mycoplasma strains for which NaCl requirement has been demonstrated. A genome search against all available marine metagenomes and 16S rRNA gene databases indicated that these two species represent a novel non-free-living marine lineage of Mollicutes, specifically associated with marine animals. Morphology and physiology were compatible with other members of this group, and genomic and phenotypic analyses demonstrated that these organisms represent two novel species of the genus Mycoplasma, for which the names Mycoplasma marinum sp. nov. and Mycoplasma todarodis sp. nov. are proposed; the type strains are PET (DSM 105487T, CIP 111404T) and 5HT (DSM 105,488T, CIP 111405T), respectively.