Phenotypes and drug resistance of clinical isolates of Escherichia coli

Abstract:

ObjectiveTo evaluate the distribution, phenotypes and resistance profiles of different kinds of βlactamasesproducing Escherichia coli (E. coli) isolated from clinic . MethodsE.coli isolated from a hospital  between July 2007 and July 2008 were collected, VITEK 2 Compact was used to identify and perform antimicrobial susceptibility test, phenotypes were determined by AESTM (Advanced Expert System) of VITEK 2 Compact. ResultsAmong 421 collected isolates, 249 (59.14%)  were extendedspectrum βlactamasesproducing (ESBLs) strains, including 67 CTXMproducing isolates; 120 (28.50%) were acquiredpenicillinaseproducing isolates; 8 (1.90%) were carbapenemaseproducing isolates; 47 (11.16%)   were wild type isolates. The total βlactamasesproducing rate was 88.84%(374/421). 174 (41.33%) isolates were from midportion urine,101(23.99%) were from  sputum; 39 (9.26%) isolates were from renal department, the other isolates were from the other departments.The resistant rates of various phenotypes of E.coli to most antimicrobial agents were quite different; The producing of ESBLs was the main cause of drugresistance of E.coli, the resistant rates of ESBLsproducing isolates were higher than acquiredpenicillinaseproducing isolates and wild type isolates (P<0.05) and were  highly resistant to most antimicrobial agents. Conclusionβlactamasesproducing rates of E.coli are high , and with various phenotypes, the most common phenotype is ESBLs; The multiply and cross drugresistance of ESBLsproducing isolates are serious, and the monitor should be paid attention, antimicrobial application should be used rationally, so as to control the emergence and spread of drugresistant strains.