[Investigation of acquired drug-resistant genes and strains relationship in Pseudomonas aeruginosa isolated from burn patients].

Objective

To investigate the acquired drug-resistant genes and strains relationship in 40 strains of Pseudomonas aeruginosa isolated from burn patients.

Methods

Forty strains of Pseudomonas aeruginosa isolated from burn patients hospitalized in our burn department from January 2014 to December 2015 were selected, with 20 strains from each year. Kirby-Bauer paper disk diffusion method was used to detect sensitivity of the isolated Pseudomonas aeruginosa to 9 kinds of antibiotics of cefotaxime, ceftazidime, cefepime, imipenem, meropenem, gentamicin, amikacin, ciprofloxacin, and levofloxacin. Polymerase chain reaction was applied to detect 9 kinds of acquired β-lactamase antibiotics-resistant genes, outer membrane porin protein oprD2 genes, 12 kinds of acquired aminoglycosides antibiotics-resistant genes, and 6 kinds of acquired disinfectant-resistant genes and genetic marker genes of mobile genetic elements. Among the above genes, positive expression genes were verified by DNA sequencing and comparison. Sequences of twenty-eight acquired drug-resistant genes of the above 40 Pseudomonas aeruginosa strains were analyzed by unweighted pair-group method with arithmetic means cluster analysis.

Results

Forty strains of Pseudomonas aeruginosa were resistant to the above 9 kinds of antibiotics. Two kinds of acquired β-lactamase antibiotics-resistant genes of bla(TEM), bla(CARB), 5 kinds of acquired aminoglycosides antibiotics-resistant genes of aac(6')-Ⅰb, aac(6')-Ⅱ, ant(2″)-Ⅰ, ant(3″)-Ⅰ, and rmtB, and 3 kinds of acquired disinfectant-resistant genes and genetic marker genes of mobile genetic elements of qacE△1-sul1, merA, and intⅠ1were detected in 40 strains of Pseudomonas aeruginosa with oprD2 gene deficiency. Forty strains aggregated obviously, with a total of 7 gene modes and 3 clones. Drug-resistant gene sequences of strains of number 2 to 4, 6 to 9, 11, 14, and 17 to 39 were similar and with close relationship. Drug-resistant gene sequences of number 12 and 13 strains were similar and with close relationship. Drug-resistant sequences of number 10 and 16 strains were similar and with close relationship.

Conclusions

Genes of bla(TEM), bla(CARB), aac(6')-Ⅰb, aac(6')-Ⅱ, ant(2″)-Ⅰ, rmtB, qacE△1-sul1, merA, and intⅠ1 were prevalent in these strains of Pseudomonas aeruginosa with oprD2 gene deficiency isolated from burn patients, which may play key roles in resistance of Pseudomonas aeruginosa to β-lactamase, aminoglycoside, and quinolone antibiotics, and the drug-resistant phenotypes were in good coincidence with genotypes. Pseudomonas aeruginosa strains isolated from burn patients were with similar acquired drug-resistant genes and close relationship.