[Antimicrobial resistance of Escherichia coli isolates collected from inpatients and outpatients].

OBJECTIVE

To investigate the antimicrobial resistance of Escherichia coli (E. coli) isolates collected from the inpatients in the departments of medicine, surgery, and pediatrics, and intensive care unit (ICU), and from the outpatients.

METHODS

Disc diffusion test was used to study the antimicrobial resistance of 3909 strains of E. coli collected from the inpatients in the departments of medicine, surgery, and pediatrics, and Intensive care unit (ICU), and from the outpatients, mostly isolated from urine, sputum, blood, and different secreta in the year 2001. WHONET 5 software was used for analysis of the antimicrobial resistance; and significant differences were tested by chi(2) to compare the resistance rates to antibiotics.

RESULTS

The incidences of extended-spectrum beta-lactamases producing strains were 11.2% (195/1737), 14.3% (141/983), 17.7% (28/158), 19.7% (24/122) and 8.4% (76/909) in the strains of E. coli isolated from the inpatients in the departments of medicine, surgery, and pediatrics, and ICU and from the outpatients respectively, with a detectable rate among the outpatients significantly lower than that among the inpatients (P < 0.005), and a detectable rate among the inpatients in the department of medicine significantly lower than those among the inpatients in the department of pediatrics and ICU (both P < 0.05). The resistance rates to cefazolin, cefotaxime, gentamicin and aztreonam of the isolates from the outpatients were significantly lower than those of the inpatients (all P < 0.05). The resistance rates to amoxicillin/clavulanic acid, ceftazidime, cefepime and amikacin of the isolates from the outpatients were significantly lower than those of the inpatients in the department of surgery and ICU (all P < 0.05); The resistance rates to ciprofloxacin and trimethoprim/sulfamethoxazole of the isolates from the outpatients were significantly lower than those from the ICU patients (both P < 0.05). The resistance rates to cefazolin and cefotaxime of E. coli isolates collected from the inpatients in the department of medicine were significantly lower than those of the isolates from the department of surgery and ICU (all P < 0.01); the resistance rates to gentamicin of the isolates from the department was significantly lower than that of the isolates from the department of surgery (P < 0.05). The resistance rates to amoxicillin/clavulanic acid and aztreonam of the isolates from the department of medicine were significantly lower than those of the isolates from the ICU (both P < 0.05). The resistance rate to ciprofloxacin of isolates from the inpatients in the department of pediatrics was significantly lower than that of the other isolates (all P < 0.01).

CONCLUSIONS

It is of guiding significance for empirical use of antimicrobial agents in clinic to study on the resistant rates of the strains of E. coli isolated from different departments in hospital.