ABSTRACT
Objective To investigate antimicrobial resistance of Escherichia coli (E.coli )isolated from patients with bloodstream infection,and provide evidence for rational use of antimicrobial agents in clinical practice.Methods BacT/A-lert automated blood culture system and VITEK 2 automated identification system were used for bacterial culture and identi-fication.Antimicrobial susceptibility testing and detection of extended-spectrum β-lactamases (ESBLs)-producing strains were performed by Kirby-Bauer method.Results From 2009 to 2011 ,a total of 235 strains of E.coli were isolated from patients with bloodstream infection,90 (38.30%)of which were ESBLs positive strains.The resistant rates of ESBLs-producing strains to ampicillin,cefotaxime and ceftriaxone were all 100%,but susceptibility rate to imi-penem/cilastatin and meropenem were all 100%,to cefmetazole and amikacin were >90%.The resistant rate of non-ESBLs-producing strains to ampicillin was the highest (70.63%),susceptibility rate to imipenem/cilastatin and meropenem were both 100%,to amikacin,cefotaxime,and cefmetazole were all >95%.The resistant rate of ES-BLs-producing strains was significantly higher than that of the non-ESBLs-producing strains.Ofβ-lactamase inhibi-tor,only susceptibility rate of ESBLs-producing E.coli to cefoperazone/sulbactam was>90%,susceptibility rates to piperacillin/tazobactam and ticarcillin/clavulanate were both<80%.Conclusion Antimicrobial resistant rate of ESBLs-producing strains causing bloodstream infection is high,individualized treatment strategies should be made according to antimicrobial resistance of bacteria causing infection in patients.
ABSTRACT
Objective To monitor the constituents and resistant tendency of bacterial pathogens isolated from diarrheal patients in our hospital form 1994 to 2005 to offer the basis for guiding epidemiologic study,vaccination research and clinical treatment. Methods Enteric pathogenic bacteria were cultured and identified to species,group and serotype with biochemical and serologic methods and the susceptibility of bacteria to antimicrobial agents were tested. Results Enteric pathogenic bacteria were isolated predominantly in male patients and mainly in children and youngsters. It reached a peak from July to September every year. Shigella spp.(75.11%) was the most frequendy isolated pathogens and followed by Vibrio spp.(12.7%),Salmonella spp.(6.28%),Aeromonas spp.(4.43%) and Escherichia coli(1.25%).During the period from 1994 to 2005,diarrheal pathogens had a trend of decrease especially Shigella spp.and Salmonella spp.. Of the 6329 isolates of Shigella spp., 75.62% was S. flexneri and S.soanei,S.dysenteriae and S. boydii constituted 23.98%,0.22% and 0.01% respectively.The sensitivity of different species,group or serotype to different antimicrobial agents was not the same.S.flexneri and Aeromonas spp. were highly resistant to most of antibiotics. However, S.sonnei and Vibrio spp.had good susceptibility to antibiotics tested except trimethoprim/sulfamethoxazole and ampicillin. Conclusion There are many species and serotypes of enteric pathogenic bacteria causing infective diarrhea and the distribution changes gradually in Beijing. The resistance rate of enteric pathogenic bacteria to antibiotics is not the same in different species and serotypes.so strict surveillance iS always needed.