Detection of extended-spectrum β-lactamase and analysis of antibiotics resistance in clinical isolates among community-acquired infections

Objective: To determine the productive rates of extended-spectrum β-lactamase(ESBLs) in the clinical isolates of Gram-negative bacteria in community-acquired infections, and investigate their resistance to 11 kinds of antibiotics. Methods: ESBLs were detected by the double disc diffusion method among clinical isolates of gram-negative bacteria. Antibiotic susceptibility test was performed by Kirby-Bauer disk diffusion method. The χ2 test was used to analyze test results. Results: In the clinical isolates of community-acquired infections, E.colithe﹑P.aeruginosa and K.pneumoniae were the most usual pathogens. The productive rate of ESBLs detected among community-acquired infections was 17.6%, the productive rate of E.cloacae and K.pneumoniae and E.coli were 23.5%, 18.5% and 18.1% respectively. The productive rate of ESBLs detected among community-acquired infections (17.6%) was significantly lower than that of hospital infections (χ2 test, P0.05). Except Cefoperazone/sulbactam, Amikacin, Imipeum Piperacilin/Tazobactams,there were significant differences between the resistance of ESBLs-producing strains to other seven kinds of antibiotics (gentamycin, ceftazidime, ciprofloxime cefepime, aztreonam, cefoperazone) and that of non-ESBLs-producing strains(χ2 test,P0.05). The resistance rates of community-acquired and hospital strains to Imipenum were 0 and 0.5% respectively, there was no significant difference between them (χ2 test,P0.05). Excluding Imipenum,the resistance rates of other antibiotics of the clinical isolates detected among community-acquired infections were both significantly lower than those among hospital infections (χ2 test,P0.05). Conclusions: The drug-resistance of Gram-negative bacteria detected among community-acquired infections is serious, for which the drug abusing and ESBLs are important factors. Strengthened the supervision towards antibiotics and decreased the abusing of antibiotics, should be given.