ABSTRACT
Mycoplasma hominis has been previously described as a heterogeneous species, and in the present study intraspecies diversity of 20 M. hominis isolates from different individuals was analyzed using parts of the unlinked gyrase B (gyrB), elongation factor Tu (tuf), SRalpha homolog (ftsY), hitB-hitL, excinuclease ABC subunit A (uvrA) and glyceraldehyde-3-phosphate dehydrogenase (gap) genes. The level of variability of these M. hominis genes was low compared with the housekeeping genes from Helicobacter pylori and Neisseria meningitidis, but only few M. hominis isolates had identical sequences in all genes indicating the presence of recombination. In order to test for intergenic recombination, phylogenetic trees were reconstructed for each of the genes but no well-supported bifurcating phylogenetic trees could be obtained. The genes were tested for intragenic recombination using the correlation between linkage disequilibrium and distance between the segregating sites, by the homoplasy ratio (H ratio), and by compatibility matrices. The gap gene showed well-supported evidence for high levels of recombination, whereas recombination was less frequent and not significant within the other genes. The analysis revealed intergenic and intragenic recombination in M. hominis and this may explain the high intraspecies variability. The results obtained in the present study may be of importance for future population studies of Mycoplasma species.
Subject(s)
Genetic Variation , Mycoplasma hominis/genetics , Recombination, Genetic , Bacterial Proteins/genetics , DNA Gyrase/genetics , Endodeoxyribonucleases/genetics , Escherichia coli Proteins/genetics , Genes, Bacterial , Glyceraldehyde 3-Phosphate Dehydrogenase (NADP+)/genetics , Humans , Models, Genetic , Molecular Sequence Data , Mycoplasma hominis/isolation & purification , Peptide Elongation Factor Tu/genetics , Phylogeny , Receptors, Cytoplasmic and Nuclear/genetics , Sequence Analysis, DNAABSTRACT
The gap gene encodes the glycolytic enzyme glyceraldehyde 3-phosphate dehydrogenase (GAPDH). The gene was cloned and sequenced from the Mycoplasma hominis type strain PG21(T). The intraspecies variability was investigated by inspection of restriction fragment length polymorphism (RFLP) patterns after polymerase chain reaction (PCR) amplification of the gap gene from 15 strains and furthermore by sequencing of part of the gene in eight strains. The M. hominis gap gene was found to vary more than the Escherichia coli counterpart, but the variation at nucleotide level gave rise to only a few amino acid substitutions. To verify that the gene was expressed in M. hominis, a polyclonal antibody was produced and tested against whole cell protein from 15 strains. The enzyme was expressed in all strains investigated as a 36-kDa protein. All strains except type strain PG21(T) showed reaction to a 104-kDa band in addition to the expected 36-kDa band. The protein reacting at 104 kDa is a M. hominis protein with either an epitope similar to one on GAPDH, or it is an immunoglobulin binding protein.
Subject(s)
Genetic Variation , Glyceraldehyde-3-Phosphate Dehydrogenases/genetics , Mycoplasma hominis/enzymology , Mycoplasma hominis/genetics , Amino Acid Sequence , Animals , Base Sequence , Blotting, Southern , Chromosome Mapping , Cloning, Molecular , Cross Reactions , Electrophoresis, Polyacrylamide Gel , Glyceraldehyde-3-Phosphate Dehydrogenases/chemistry , Glyceraldehyde-3-Phosphate Dehydrogenases/immunology , Glyceraldehyde-3-Phosphate Dehydrogenases/metabolism , Humans , Molecular Sequence Data , Mycoplasma Infections/microbiology , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , Rabbits , Sequence Analysis, DNAABSTRACT
We analyzed Mycoplasma hominis, Mycoplasma fermentans and Ureaplasma urealyticum antigens by immunochemical methods. The immunochemical reaction showed that all three species bound to the surface of one medium component, which origin stemmed from the horse serum. This substance functioned as one of the most potent components of mycoplasma immunogens for all three species.
