Adherence and damage to epithelial cells of human lung by Ureaplasma urealyticum strains biotype 1 and 2

Abstract

Ureaplasma sp. is associated with chronic lung disease and it has been implicated in the morbidity and mortality of new born babies (human). Adherence is an important process for lung infection, and scarce information is available in this respect. This work shows its adhesion to epithelial cells from the respiratory tract in culture, and evaluates the Ureaplasma sp. references and clinical strains isolated from premature newborns. Ureaplasma parvum and Ureaplasma urealyticum serotype 8 and five clinical samples were evaluated, using the Bertholet assay. They were observed by scanning and transmission electron microscopy to A549 cell line. Adherence was abolished by pre-treatment of ureaplasmas with A549 cell extracts and inhibited by pretreatment of ureaplasmas with N-acetylneuraminic acid, trypsine, glucose and monoclonal antibodies (mAb 106.C anti-MB against U. parvum serotype 3). Ureaplasma sp. (biotypes 1 y 2) adherence had no significant difference (P = 0.127). The clinical strains by scanning electron microscopy showed a similar damage. Both reference and clinical strains produced evident changes in cell morphology. Micro-colonies were observed on the cells. By transmission electron microscopy, ureaplasmas attached on the cell surface and into the cytoplasm were observed. The A549 cellular line is a good model for the study of adherence ofUreaplasma sp. The urease test by Bertholet assay is a good indicator of colonization. These data suggested that ureaplasma adhesins are proteinaceous antigenic substance. Inhibition assays with neuraminidase and glucose showed binding to sialic acid residues and suggested as possible adhesin to MB (Multi banded antigen). Key words: Ureaplasma urealyticum, adherence, epithelial cells, damage