The genotype study for the Escherichia coli extended spectrum β-lactamase in Macao and Shenyang, China / 中华检验医学杂志

ABSTRACT

Objective To identify the genotypos of extended spectrum β-1actamase (ESBLs)-producing of Escherichia coli ( E. coli) clinical strains isolated from the Macao and compare the results with the genotypes of clinical strains collected in the first Clinical College, China Medical University (CMU) in Shengyang. Methods The clinically isolated E. coli strains including 209 strains from Macao and 150 strains from CMU were collected. Based on the standard of CLSI2006, the ESBLs-producing strains was identified and its isoelectric point(pI) value was detected by isoelectric focusing (IEF) method. The pI values were used to design the primers for PCR amplification. The amplified DNA sequences were then compared with the GenBank and the ESBL genotypes were confirmed. Results ( 1 ) The positive rate of ESBLs-producing strains of E. coli was 30. 1% (62/209) from Macao and 54. 0% (81/150)from CMU. (2)The genotype of 56 (90. 5% ) β-lactamase(ESBLs)-producing E. cull strains from Macao was CTX-M56. Most of them were CTX-M-14 (76. 2% ), other genotypes including CTX-M-9 (4. 8% ), CTX-M-22 (3.2%), CTX-M-24(3.2%), CTX-M-27(1. 6% ), and CTX-M-15( 1.6% ) were found. Six strains were unidentified. (3)The genotype of 74(91.5% )β-lactamase(ESBLs) -producing E. coli strains from Shenyang was CTX-M. Most of them were CTX-M-14 (65.4%), other genotypes including CTX-M-3 ( 13.6% ), CTX-M-24 (4. 9% ),CTX-M-22(2.5%), CTX-M-15(2.5%), CTX-M-9(1.2%) and CTX-M-28(1.2%) were found. Seven strains were unidentified. Conclusions CTX-M genotypo was the mostly identified ESBL-preducing E. Coli strains from Macao and the results were similar with that from CMU. Among them, the CTX-M-14 was the major genotype. Other genotypes included CTX-M-9, CTX-M-15, CTX-M-22, CTX-M-27, and CTX-M-24.However, two genotypes of CTX-M-3 and CTX-M-28 were not found in the clinical isolates in Macao and one genotype of CTX-M-27 was not found from the CMU clinical isolates.