Correlation between virulence genotype and fluoroquinolone drugs resistance in Pseudomonas aeruginosa of lower respiratory tract infection / 中国人兽共患病学报

ABSTRACT

We investigated the correlation between toxin gene exoS,exoU and fluoroquinolone resistance in lower respiratory tract infection with P.aeruginosa so as to provide guidance for reasonable treatment of clinical infections.We collected P.aeruginosa of sputum samples in hospitalized patients from October 2015 to March 2016.The antimicrobial susceptibility was tested by liquid dilution method.The exoS and exoU genes were detected by PCR technique.Results showed that forty-six P.aeruginosa strains were identified from sputum.The exoS and exoU gene positive rate were 86.96 ％ (40/46) and 69.57 ％ (32/ 46) respectively,and the highest proportion of genotype was exoS+/exoU+ (60.87％,28/46).Among them,36.96％ (17/ 46) were multiple drug-resistant bacteria(MDR).Fluoroquinolone non-sensitive (FQ-NS) strain were 78.95％ (15/19) for MDR and 89.47 ％ (17/19) exoU gene were positive,which was significantly higher than the fluoroquinolone sensitive strains (FQ-S).Compared with the FQ-S strain,FQ-NS strains were serious drug resistance.The drug resistant rate of eefepime and aztreonam were more than 70％,and then meropenem and imipenem were more than 50％.The drugs of lower resistance rate in FQ-NS strain had polymyxin B(10.53％,2/19),amikacin(10.53％,2/19),ceftazidime (15.79％,3/19) and gentamicin (21.05％,4/19).P.aeruginosa of lower respiratory infection carried toxin genes exoS and exoU were higher,the main genetpy was exoS+/exoU+.FQ-NS strains were higher drug resistance rate and a higher proportion of exoU+ strains than FQ-S strains.We should strengthen virulence genes test and drug resistance monitoring in clinical practice.