© 2005, American Society for Microbiology
Swine and Poultry Pathogens: the Complete Genome Sequences of Two Strains of Mycoplasma hyopneumoniae
and a Strain of Mycoplasma synoviae†
LNCC/MCT, Petrópolis, RJ,1 Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS,2 Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS,3 Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ,4 Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP,5 Universidade Federal do Amazonas, Manaus, AM,6 Universidade Federal de Minas Gerais, Belo Horizonte, MG,7 Universidade de Brasília, Brasília, DF,8 Universidade Estadual de Campinas, Campinas, SP,9 EMBRAPA/Empresa Pernambucana de Pesquisa Agropecuária, IPA, Recife, PE,10 Ludwig Institute for Cancer Research, São Paulo, SP,11 Instituto de Informática, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS,12 Universidade Federal do Pará, Belém, PA,13 Universidade Estadual de Santa Cruz, Ilhéus, BA,14 Universidade Católica de Brasília, Brasília, DF,15 Universidade Federal de Pelotas, Pelotas, RS,16 Instituto de Biologia Molecular do Paraná, Curitiba, PR,17 Universidade Federal de Santa Catarina, Florianópolis, SC,18 CNPSA/EMBRAPA, Concórdia, SC,19 Universidade Federal Rural de Pernambuco, Recife, PE,20 Universidade Federal do Ceará, Fortaleza, CE,21 EMBRAPA Milho e Sorgo, Sete Lagoas, MG,22 EMBRAPA Soja, Londrina, PR,23 Universidade Federal do Rio Grande do Norte, Natal, RN,24 Instituto Nacional de Pesquisas da Amazônia, Manaus, AM,25 Universidade Federal de Santa Maria, Santa Maria, RS,26 Pontifícia Universidade Católica do Paraná, São José dos Pinhais, PR,27 Instituto Nacional de Cāncer, Rio de Janeiro, RJ,28 Universidade Federal de Alagoas, Maceió, AL,29 Universidade Federal do Paraná, Curitiba, PR,30 Universidade Federal de Goiás, Goiānia, GO, Brazil,31 Ludwig Institute for Cancer Research, New York, New York32
Received February 3, 2005; Accepted May 19, 2005.
Mycoplasmas comprise a group of more than 180 species of wall-less bacteria that are obligate parasites of a wide range of organisms including humans, plants, and animals (46
). Mycoplasmas typically exhibit strict host tissue specificities, probably due to their nutritional requirements (45
), a direct consequence of the genome reduction that likely occurred as a consequence of the metabolic complementarity of their hosts (3
). The evolutionary dynamics of these organisms involved population bottlenecks and asexual reproduction leading to accumulation of deleterious mutations, which resulted in further genome contraction (58
). A predictable consequence of this process is preservation of a minimal genome comprising essential genes to maintain basic core functions and adaptation to specific environments.
Two species, Mycoplasma hyopneumoniae
and Mycoplasma synoviae
, have a significant adverse economic impact on animal production. The former is the infective agent of enzootic pneumonia in pigs, which results in deactivation of mucociliary functions (15
) and increased susceptibility to secondary infections (12
). The latter is responsible for respiratory tract disease and synovitis in chickens and turkeys. It can be transmitted vertically through contaminated eggs (28
), resulting in considerable losses due to reduced egg production and meat quality as well as a lowered rate of viable hatchings. Thus, knowledge of their respective biological characteristics seems of paramount importance.
The genomes of several mycoplasmas have been sequenced and analyzed in recent years (11
), but comparative analyses of species belonging to the Pneumoniae and Hominis clades have not been undertaken. In addition, interstrain, whole-genome comparisons have not yet been carried out, although the genes involved in DNA repair, including those of the organisms herein studied, have recently been analyzed (10
Here we report the complete genome sequences of a pathogenic (7448) and a nonpathogenic (J [ATCC 25934]) strain of M. hyopneumoniae and the complete genome of M. synoviae strain 53. Comparative analyses of the M. hyopneumoniae strains allowed the identification of strain-specific regions that might be related to their variable pathogenicity. A detailed phylogenetic analysis of several mycoplasma species belonging to the Pneumoniae and Hominis clades was also carried out, comparing metabolic pathways and genes involved in the adhesion process. Comparisons of M. gallisepticum and M. synoviae genomes pointed to the evolutionary origin of the hemagglutinin gene family and showed evidence of horizontal transfer of other gene clusters.