[The biological characteristics of a mucoid Pseudomonas aeruginosa strain with a newly discovered mutation of mucA gene].

Objective: To compare the mucA gene sequence, biofilm formation, growth rate and antibiotic resistance of a mucoid Pseudomonas aeruginosa strain 'PA17' with those of the nonmucoid strain PAOI.

Methods: The mucA genes of PA17 and PAOI were amplified and the PCR products were sequenced. Biofilm was established and detected with scanning electron microscope 8 h, 24 h, 3 d and 6 d later. Clones counting method was used to compare the growth curves of PA17 and PAOI. International standard plate dilution method was used to detect the susceptibility of common antibiotics for PA17 and PAOI in vitro.

Results: There was a 166-333 deletion mutation in mucA gene of PA17. The biofilm formation rate and growth rate of PA17 were noticeably lower than those of PAOI. The antibiotic resistance profile of PA17 was identical to that of PAOI.

Conclusion: A mucoid Pseudomonas aeruginosa with a new type of mutation of mucA gene is discovered. The biologic characteristics of this strain are different from those of the mucoid Pseudomonas aeruginosa strain reported previously, which may be related with the newly discovered mutation of mucA gene.