High inter-species and low intra-species variation in 16S–23S rDNA spacer sequences of pathogenic avian mycoplasmas offers potential use as a diagnostic tool

• Published in: Veterinary microbiology 2008-04, Vol.128 (3), p.279-287
• Main Authors: Ramírez, A.S., Naylor, C.J., Pitcher, D.G., Bradbury, J.M.
• Format: Article
• Language: English
• Subjects: 16S-23S rDNA spacer sequences; animal pathogenic bacteria; Animals; Bacteriology; Base Sequence; Biological and medical sciences; bird diseases; Bird Diseases - diagnosis; Bird Diseases - microbiology; Birds; Cloning, Molecular; diagnostic techniques; disease diagnosis; DNA, Intergenic - chemistry; DNA, Ribosomal Spacer - chemistry; Fundamental and applied biological sciences. Psychology; genetic polymorphism; Genetic Variation; inter-species variation; Intergenic spacer region; intergenic spacer regions; intra-species variation; microbial genetics; Microbiology; Miscellaneous; Molecular Sequence Data; Molecular Weight; Mollicutes; Mycoplasma; Mycoplasma - classification; Mycoplasma - genetics; Mycoplasma - isolation & purification; Mycoplasma gallisepticum; Mycoplasma Infections - diagnosis; Mycoplasma Infections - microbiology; Mycoplasma Infections - veterinary; Mycoplasma meleagridis; Mycoplasma synoviae; Phylogeny; Polymerase Chain Reaction - veterinary; ribosomal DNA; RNA, Ribosomal, 16S - genetics; RNA, Ribosomal, 23S - genetics; Sequence Analysis, DNA - veterinary; Sequence Homology, Nucleic Acid; species differences; Species Specificity
• ISSN: 0378-1135; 1873-2542
• DOI: 10.1016/j.vetmic.2007.10.023

In order to investigate its value for phylogenetic analysis, species characterisation and diagnosis, the 16S–23S rDNA intergenic spacer regions (ISRs) of the type strain of 23 avian Mycoplasma species were amplified and the sequences determined. Also sequenced were the reference strains of Mycoplasma iowae serotypes J, K, N, Q and R and a number of field strains of Mycoplasma synoviae, Mycoplasma gallisepticum, Mycoplasma meleagridis and M. iowae. The ISRs demonstrated a high level of size variation (178–2488 bp) between species and did not include tRNA genes. Phylogenetic analysis performed using the information conflicted with that based on the 16S rDNA and was therefore not helpful for phylogenetic studies. However, the ISR did appear to be of value for determining species since there was high inter-species variation between all 23 avian Mycoplasma species, and in addition there was low intra-species variation, at least in the four pathogenic species. It could also be very useful as additional information in the description of a new species and as a target for species-specific PCRs.