In vitro influence of Mycoplasma species on the stimulation of human polymorphonuclear granulocytes

The influence of Mycoplasma species (sp.) on the stimulation of human polymorphonuclear neutrophil granulocytes (PMNG) was determined by means of the luminol-dependent chemiluminescence (CL) method. When opsonized Mycoplasma sp. were used the CL response of PMNG was greater than in the presence of nonopsonized strains. Nonopsonized and nonspecifically opsonized Mycoplasma sp. showed a different CL response pattern. The stimulation of PMNG was with M. pneumoniae significantly weaker than with the other Mycoplasma sp. Using isolated M. hominis strains always the same CL-reaction of PMNG was observed. On the other hand, with 12 isolated U. urealyticum strains different results were obtained; 9 strains isolated from the upper urogenital tract lead to a slight PMNG stimulation comparable to that of M. pneumoniae. No correlation was found between CL response and bacterial killing. The weak stimulation of PMNG by M. pneumoniae and most of the U. urealyticum isolates suggest that this behaviour could be a factor of pathogenicity.