Adherence of Pseudomonas aeruginosa to human tracheobronchial mucin

Abstract

A microtiter plate assay was developed to study the adherence of Pseudomonas aeruginosa to purified human tracheobronchial mucin. The wells of the plates were treated with silicon to minimize nonspecific binding of bacteria and then coated with a solution of purified human tracheobronchial mucin. Bacteria were added to the wells, and the plates were incubated at 37°C. The wells were washed 15 times in an automated microtiter plate washer, and the bacteria bound to wells were desorbed with Triton X-100 and plated for enumeration. Scanning electron microscopy verified bacterial adherence to the mucin-coated wells and desorption of bacteria by Triton X-100. Adherence of P. aeruginosa increased as the concentration of mucin used to coat the wells was increased, with saturation occurring at 0.5 p,g of mucin protein per ml. Other parameters that affected adherence included the time of incubation and concentration of bacteria. Similar studies with strains of Escherichia coli and Klebsiella pneumoniae indicated a relative lack of binding of these bacteria to mucin. In comparing different strains of P. aeruginosa, there were small differences in binding between strains. It is inferred that there may be specific sites on human tracheobronchial mucin which facilitate this preferential binding.

Strain- and matrix-dependent adhesion of Lactobacillus plantarum is mediated by proteinaceous bacterial compounds

“…(1988). The protocol was based on a study of the ability of Pseudomonas aeruginosa to adhere to mucin (Vishwanath and Ramphal 1984). Mucin was dissolved in phosphate‐buffered saline (PBS) (pH 7·0) to a final concentration of 10 mg ml −1 .…”

Respiratory-mucin inhibition of the opsonophagocytic killing of Pseudomonas aeruginosa

“…Bacteria. Three mucoid P. aeruginosa strains-M35, M2192, and M264-used in these and previous studies have been described before (1,16). Nonmucoid P. aeruginosa strains included strains 9882 (lipopolysaccharide [LPS] smooth, Fisher immunotype 2) isolated from the blood of an immunocompromised patient, strain 15921 (LPS smooth, Fisher immunotype 1), a clinical isolate similar to strain 9882, and ATCC 27314 (LPS smooth, Fisher immunotype 3).…”

“…Unlike many other gram-negative bacteria which seldom chronically colonize the respiratory tract, P. aeruginosa adheres well to respiratory mucin (16). Therefore, adherence to mucin may contribute toward this organism's ability to colonize the respiratory tract.…”

The tear film and ocular mucins

“…The MUC1 mucin product is highly negatively charged because of its sialic acid residues. 64 This negative charge may directly repel pathogens from the epithelial surface 72 and lead to repulsion between molecules, thus enhancing the movement of mucus across the corneal epithelium. 64 Owing to a high sialic acid content, ocular mucins may bind to and provide antiviral effects.…”

“…They may bind to corneal epithelial bacterial receptors, thus competitively blocking the adherence of bacteria. 32,71,72 Epithelial corneal binding sites have been identified for Pseudomonas aeruginosa, so it is possible for mucin to protect against Pseudomonas sp. infection by competitive inhibition.…”