engleski

In Vitro Adherence Ability of Pseudomonas aeruginosa Strains Isolated from Patients with Cystic Fibrosis.

Background: Pseudomonas aeruginosais a frequent cause of chronic pulmonary infection associated with cystic fibrosis (CF). The bacteria are capable of colonizing the lings of CF paients for years due to alginate overproduction and biofilm formation. The ability of P. aeruginosa to adhere to epithelial cells is considered the initial step in its colonization and subsequent infection. Thius study was undertaken to examine the adherence ability of strains isolated from childern with CF to two different continuous cell lines. Metodhs: The ability of 59 wild-type strains of P. aeruginosa to adhere to the HeLa and Buffalo Green Monkey Kidney (BGMK) cells was investigated. Twenty strains were isolated from sputa of cystic fibrosis patients, while 19 strains were isolated from tracheal aspirates (TAs) and 20 from bronchial secretions (BSs) of patients without CF and they were used as a control group. Microscopy was used to evaluate the adherence ability, and a number of bacteria attached to the 40 cells was counted. Results: Most strains (71%) adhered well to the used cell lines. There were no significant difference between adherance to the HeLa and to the BGMK cells. The statistically significant difference was observed between adherence ability of strains isolated from sputa of patients with CF and strains from TAs and BSs of patients witouth CF. While most of the tracheal and bronchial isolates were hyperadhesive (51-110 bacteria per cell) most of the cystic fibrosis isolates adhered poorly to the HeLa and BGMK cells (1-10 bacteria per cell). The bacterial binding to the cells was blocked when bacteria were incubated at 80°C for 20 min before the adherence assay. Conclusion: These results indicate that alginate is not involved in the adherence of P. aeruginosa to the used epithelial cell lines, and, because of that, mucoid strains isolated from persistently colonized cystic fibrosis patients showed poor adherence ability.

Pseudomonas aeruginosa; adherence ability; cystic fibrosis

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