A comparison of the adherence of fimbriated and nonfimbriated Haemophilus influenzae type b to human adenoids in organ culture

Abstract

Adherence of fimbriated and nonfimbriated variants of a single strain of Haemophilus influenzae type b to organ cultures of human adenoidal tissue was measured by three assays, two of which were quantitative. In one assay, the adherence of radioactively labeled bacteria was measured; the numbers of CPU of bacteria per gram of adenoidal tissue were 16.0 ± 6.7 for fimbriated bacteria and 10.2 ± 4.0 for nonfimbriated bacteria (P < 0.05). In the second assay, adherent CFU were determined directly; the results were 23.4 ± 17.2 CFU/g of tissue for fimbriated bacteria and 5.1 ± 2.2 CFU/g for the nonfimbriated variant (P < 0.02). By combining data from the two assays it appears that fimbriated and nonfimbriated bacteria do not compete for the same site on the tissue, and that the adherent bacteria do not change their state of fimbriation under the assay conditions used. In contrast, the third assay, scanning electron microscopy, showed very poor adherence of nonfimbriated bacteria. Fimbriated bacteria, on the other hand, adhered in clusters to nonciliated epithelial cells. Overall, the data indicate that fimbriae enhance adherence of H. influenzae type b to a type of tissue that is a normal site of huinan colonization and that nonfimbriated bacteria adhere by a distinctly different mechanism.

Tissue culture adherence and haemagglutination characteristics of Moraxella (Branhamella) catarrhalis

“…The presence of more than one type of adhesin is not uncommon in bacteria [26,27]. Haemagglutinating activity does not always correlate with epithelial cell adherence, as has been demonstrated in the case of Salmonella typhimurium [28], Gardnerella vaginalis [29] and H. in£uenzae [30,31].…”

Molecular determinants of the pathogenesis of disease due to non-typableHaemophilus influenzae

“…Studies with adenoids and nasal turbinate tissue in organ culture indicate that piliated organisms tend to adhere to areas of damaged epithelium [101–103]. To underscore the potential role of pili in H. influenzae colonization, Weber et al demonstrated that, in yearling monkeys, the density of colonization was greater for piliated H. influenzae type b than for isogenic non‐piliated organisms with an insertionally inactivated hifA gene [104].…”

Interaction of vitronectin with Haemophilus influenzae

“…Protein D has also been shown to mediate cell adhesion [7]. The colonisation is often asso-ciated with epithelial damage and breakdown of tight junctions whereby the bacteria come in contact with the underlying basement membrane and extracellular matrix (ECM) [2,3,8,9]. We have earlier been able to demonstrate that H. in£uenzae can interact with basement membrane as well as with distinct matrix components such as laminin, ¢bronectin and collagen.…”