[MucA mutation and its alginate-production in clinically isolated Pseudomonas aeruginosa].
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 strains 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).


CONCLUSIONS
MucA mutation correlates with the alginate production and phenotype of bacterial colonies.
Meng
Jie
J
Department of Respiratory Diseases, Xiangya Hospital, Central South University, Changsha 410008, China.
Hu
Chengping
C
Luo
Bailing
B
D000464:Alginates; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D020723:Glucuronic Acid / Q000096:biosynthesis; D006603:Hexuronic Acids; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D011550:Pseudomonas aeruginosa / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*
D000464:Alginates; D001426:Bacterial Proteins; D006603:Hexuronic Acids; C107895:MucA protein, Pseudomonas; D020723:Glucuronic Acid