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OBJECTIVE To investigate the distribution and resistance characteristic of Escherichia coli in order to provide reference for the clinical application of drugs.METHODS The strains of E.coli were detected and their sensitivity to antibiotics was determined by VITEK automatic bacterium identifying and drug sensitivity analyzing systems,then the specimens in which E.coli was detected and the result of sensitivity to antibiotics were analyzed.RESULTS Among 210 specimens in which E.coli was detected,the urine was the most frequent.There were 46 strains which produced extended-spectrum ?-lactamases(ESBLs),the ESBLs-producing rate of E.coli was 21.9%,the drug resistance of ESBLs producers was more serious than that of nonproducers.The resistant rate of ESBLs producers against penicillins was 100%,but the susceptibility rate was 19.6-84.8% while combined with the ?-lactamases inhibitors.The susceptibility rates of ESBLs producers to the antibiotics from the first generation cephalosporins to the third generation ones were 0.0-45.6%.The susceptibility rates of ESBLs producers to cefepime,cefoxitin,ciprofloxacin and Cotrimoxazole were 60.9%,34.8%,10.9% and 13.0%,respectively,whereas amikacin,imipenem,and meropenem were more effective against the bacteria,the susceptibility rates of ESBLs producers were 89.1%,97.8% and 97.8%,respectively.while all the nonproducers were susceptible to them.The ESBLs producers had high sensitivity to imipenem,meropenem,amikacin and piperacillin/tazobactam,and had high resistance to the other antimicrobial drugs,they showed multi-drug resistance.CONCLUSIONS It is rather serious the resistance of E.coli to usual antibiotics,and that of ESBLs producers is more serious.It should be cautious to use cephalosporins to treat infections caused by E.coli,carbapenem,amikacin and some of complex antibiotics containing ?-lactamases inhibitor are very effective to treat infections caused by ESBLs producers.It is very important to select rational drugs correctly for clinical treatment of the infections according to the results of antibiotics susceptibility tests.
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OBJECTIVE To investigate the characteristic of clinical distribution and drug resistance of pathogenic bacteria in lower respiratory tract infection. METHODS Bacterial culture of the lower respiratory tract samples collected from patients who were admitted from Jan to May 2008 was done.The bacteria identification and drug sensitivity tests were done by VITEK bacterium identifying and drug sensitivity analyzing system. RESULTS A total of 502 pathogens were isolated,in which 340 strains of Gram-negative bacteria(67.7%),32 strains of Gram-positive cocci(6.4%)and 130 strains of fungi(25.9%).Of all the 372 strains of bacteria,the most common pathogens in turn were Acinetobacter baumannii,Pseudomonas aeruginosa,Klebsiella pneumoniae and Escherichia coli,respectively.Non-fermenters were the dominant pathogens in intensive care unit(ICU)and the surgery wards,Enterobacteriaceae and fungi were the dominant pathogens in the non-operation wards.Of A.baumannii strains,the antibiotic resistant rates to imipenem and meropenem were 7.5% and 8.8%,respectively,the resistant rates to the other antibiotics were high(53.8%-100.0%,respectively).Of P.aeruginosa strains,the antibiotic resistant rates to imipenem,meropenem,polymyxicn E,ciprofloxacin,amikacin,tobramycin and gentamicin were 11.1%-27.0%,respectively,The resistant rates to the other antibiotics such as penicillins,cephalosporins and the complex antibiotics containing ?-lactamases inhibitor were 38.1%-100.0%.The ESBLs-producing rate of K.pneumoniae strains(71.7%)was higher than that of E.coli strains(29.1%).K.pneumoniae strains and E.coli strains were all sensitive to imipenem and meropenem,and both of their resistant rates against amikacin were the same(10.9%),but against the other antibiotics the resistance of E.coli strains were more serious than that of K.pneumoniae strains. CONCLUSIONS In our area,non-fermenters are mainly isolated from ICU and the surgery wards.Enterobacteriaceae and fungi are mainly isolated from the non-operation wards.The major pathogens show multi-drug resistance except imipenem,meropenem and amikacin.It′s important to prevent hospital acquired lower respiratory tract infection during the clinical therapy,and it is urgent for rational use of antimicrobial agents according to the results of antibiotics susceptibility tests.