Antimicrobial Resistance Of Common Isolated Bacteria In Geriatrics Department

Objective: This study was conducted to investigate the distribution of the bacteria isolated from the inpatients of geriatric department, analyze the result of the common bacterial susceptibility test to provide basis for the reasonable application of antibiotics.Methods: A total of 4094 strains of bacteria were collected from the inpatients of geriatric department of Tianjin Medical University General Hospital from January2011 to December 2015. Strain identification of bacteria and antimicrobial susceptibility test was performed by using disk diffusion method and VITEK-2compact automatic system with ancillary drug sensitive card. The study of drug resistance focused on 10 kinds of common bacteria, the results of antimicrobial susceptibility test were judged according to CLSI 2015 edition. The data were analyzed and described by Excel, SPSS22.0 and Whonet5.6 software.Results:(1)A total of 4094 strains of bacteria were isolated in 5 years. Among them, 2762 strains(67.46%) were isolated form the sputum specimens, 821strains(20.05%) were isolated from urine specimens, 231 strains(5.64%) were isolated from blood specimens. The annual proportion of bacteria isolated from blood were 2.0%, 4.19%, 5.88%, 6.81%, 8.32%. A total of 3064 strains(74.80%) of the 10 kinds of target bacteria were isolated.(2)The detection rate of Extended-spectrum?-lactamases(ESBLs) producing Escherichia coli was 72.96%, the yearly rates were74.10%, 75.30%, 76.50%, 66.30%, 72.20%; the detection rate of ESBLs producing Klebsiella pneumoniae was 32.65%, the yearly rates were 25.90%, 41.40%, 31.20%,30.50%, 33.60%.The cumulative resistance rate of Enterobacteriaceae to carbapenems, amikacin, cefoperazone / sulbactam and piperacillin piperacillin /tazobactam were lower than 8%. Yearly resistance rate of Klebsiella pneumoniae to imipenem were 0.0%, 1.0%, 0.8%, 1.7%, 2.7%. In nonfermenters, Yearly resistant rates of Acinetobacter baumannii and Pseudomonas aeruginosa to imipenem was26.9%, 25.8%, 29.2%, 29.9%, 18.8% and 57.9%, 38.5%, 38.9%, 48.8%, 59.1%.Resistance rate of Pseudomonas aeruginosa to Cefoperazone / sulbactam increased from 12.8% to 22.8%. Stenotrophomonas maltophilia kept sensitive to ceftazidime and cotrimoxazole, the cumulative sensitive rate of 5 years was 91.1%, 88.9%.(3)The total detection rate of methicillin-resistant Staphylococcus aureus(MRSA) was58.42%, yearly rates were 75%, 54.29%, 53.85%, 46.94%, 71.43%.Within 5years,there was no Staphylococcus aureus found resistant to this three antibiotics. The cumulative resistance rate of Staphylococcus epidermidis to vancomycin was 1.1%.The cumulative resistance rates of Enterococcus faecalis to vancomycin and linezolid were 0.8% and 2.5%. Enterococcus faecium had a 0.6% intermediary rate to linezolid.The cumulative resistance rates of Enterococcus faecium to vancomycin and teicoplanin were 1.1% and 1.0%.Conclusions:(1) During the 5 years, the bacteria isolated from the inpatients of geriatric department were mainly Gram-negative bacteria. Sputum, urine and blood were the most important sources of bacteria. The proportion of bacteria isolated from blood samples increased year by year.(2) During the 5 years, most of the Enterobacteriaceae and Nonfermenters kept low resistance rates to carbapenem,amikacin, and cefoperazone / sulbactam, piperacillin piperacillin / tazobactam, which were the compound antibiotics containing ?- lactamase inhibitor. The resistance rate of Pseudomonas aeruginosa to imipenem was relatively high, what was more, the resistance rates to imipenem and cefoperazone / sulbactam showed roughly ascendant trend. For Stenotrophomonas maltophilia, ceftazidime and cotrimoxazole were the most sensitive antibiotics.(3)During 5 years, Staphylococcus aureus was more common than Staphylococcus epidermidis, while enterococcus faecium was more common than enterococcus faecalis. Gram-positive coccus kept extremely high sensitive rates to linezolid, vancomycin and teicoplanin.