MucA mutation and its alginate-production in clinically isolated Pseudomonas aeruginosa / 中南大学学报(医学版)

ABSTRACT

Objective To determine the characterization of mucA gene mutation in clinically isolated Pseudomonas aeruginosa (P.aeruginosa), and the relation between mucA mutation and the mucoid phenotype.Methods A total of 58 strains of P.aeruginosa were collected. Of them,8 were nonmucoid phenotype and 50 were mucoid phenotype.We detected mucA mutations with PCR-SSCP and sequencing analysis. Alginate was examined by colorimetry. Results All strrains had mucA mutations (100%), 16 of the 50 (32%) isolates contained mucA mutations that could alter the encoding sequence of amino acids, and the rate in nonmucoid isolates was 0. Fourteen mutation sites were found, 5 of which could alter the encoding sequence of amino acids, and the others were silent mutations. The alginate concentration of mucoid P.aeruginosa was higher than the nonmucoid P.aeruginos(P＜0.01). The alginate concentration of the isolates which contained mucA mutations that could alter the encoding sequence of amino acid was higher than the strains only with silent mutations (P＜0.01).Conclusion mucA mutation correlates with the alginate production and phenotype of bacterial colonies.