ABSTRACT
Objective To analyze the clinical distribution and antimicrobial resistance change trend of Acinetobacter baumannii(AB) from a geriatric hospital in 2013-2016.Methods Specimen source,department distribution,and antimicrobial resistance of AB isolated from all patients in the hospital from 2013 to 2016 were analyzed retrospectively.Results From 2013 to 2016,1 712 strains of AB were isolated,AB isolation rates in 2013,2014,2015,and 2016 decreased year by year,which were 17.92％,17.17％,15.10％,and 11.81％,respectively.AB were mainly isolated from sputum (n =1 524,89.02％),followed by urine (n =79,4.61％) and blood (n=37,2.16％).The main departments of AB isolation were intensive care unit (n =798,46.61％),department of respiratory medicine (n =507,29.62％),and neurology department (n =156,9.11％).Resistance rates of AB to most antimicrobial agents increased in 2013-2016,resistance rates to compound sulfamethoxazole were low (25.68 ％-65.89 ％),followed by resistance rates to cefoperazone/sulbactam (54.74％-68.00％),resistance rates to imipenem were 71.40％-77.42％,to the other antimicrobial agents were all＞60％;in 2013-2016,resistance rates of AB to cefepime,cefoperazone/sulbactam,gentamicin,tobramycin,and compound sulfamethoxazole were significantly different (all P＜0.05).Conclusion Antimicrobial resistance rates of AB in this hospital is increasing,it is necessary to strengthen the monitoring,promote the rational use of antimicrobial agents,and block the infection and transmission of AB in hospital.
ABSTRACT
Objective To study the mechanisms on drug susceptibility and resistance of clinically multidrug-resistant Escherichia coli isolates,to provide information on related treatment.Methods The susceptibility of E.coli strains that isolated from different kinds of samples in the last 3 years on drugs was analyzed by agar dilution test,with strains that exhibiting resistances to cefotuxime,ciprofloxacin and amikacin simultaneously collected for further analysis.Resistant genes which mediate resistance to β-lactamases,fluoroquinolone and aminoglycoside as well as phylogenic type were detected by PCR amplification while genetic relation was analyzed by PFGE.Transferability of resistant plasmids was identified by conjugation test.Results In total,137 multidrug-resistant E.coli isolates were collected.Only 1％ of the isolates exhibited resistance to both imipenem and meropenem while 4％ of the strains were resistant to piperacillin/tazobactam.Most (85％) of the isolates were positive to ESBL and majority of them produced CTX-M.Target substitution and production of methylases were the main mechanisms causing resistance to fluoroquinolones and aminoglycosides respectively.Conclusion The main source of clinical multidrug-resistance was collected from urine samples.Carbapenem and enzyme inhibitor-containing antibiotics seemed to be the available antibiotics that were sentitive to the clinically multidrug-resistant E.coli isolates.