Etiological characteristics, drug susceptibility testing and ultrasonic image characteristics of mammary duct ectasia patients complicated with infections

OBJECTIVE To investigate the etiological characteristics, drug susceptibility testing and ultrasonic image characteristics of mammary duct ectasia patients complicated with infections so as to provide guidance for diagnosis and treatment of the mammary duct ectasia patients complicated with infections.METHODS The clinical data of 96 mammary duct ectasia patients complicated with infection who were treated in hospitals from Feb 2013 to Feb 2016 were retrospectively analyzed, all of the patients had definite etiological characteristics and results of drug susceptibility testing and received ultrasonic examination before treatment. The distribution of pathogens, results of drug susceptibility testing and ultrasonic image characteristics were observed.RESULTS A total of 124 strains of pathogens were isolated from 96 patients, 59.67% of which were gram-positive bacteria, and 40.33% were gram-negative bacteria; Staphylococcus epidermidis and Staphylococcus aureus were the predominant species of gram-positive bacteria; Stenotrophomonas maltophilia was dominant among the gram-negative bacteria. The results of drug susceptibility testing indicated that the drug resistance rates of the gram-positive bacteria to quinolones (levofloxacin, moxifloxacin) and tetracylines ( tigecycline, tetracycline, vancomycin, linezolid, nitrofurantoin) were less than 30%, the drug resistance rates to penicillins and cephalosporins were more than 30%; the gram-negative bacteria were highly susceptible to aminoglycosides and fluoroquinolones but were highly resistant to ampicillin, cefazolin and cefoxitin. The breast ultrasonic images of the patients were characterized byHT5"SS mass, mass without obvious envelope, frosted glassy borders, uneven echo inside the mass, mass surrounded by high-level echo and some lesions with bubble sign.CONCLUSION The gram-positive bacteria are dominant among the pathogens causing the infections in the patients with mammary duct ectasia and are highly susceptible to quinolones and tetracyclines. The patients show specific ultrasonic images, which have certain value in differential diagnosis.