健康人肠道大肠埃希菌耐药性与质粒图谱的研究

目的 研究深圳市健康人肠道大肠埃希菌携带的质粒与其耐药性之间的关系.方法 分离健康人肠道大肠埃希菌,K-B法测定细菌对16种抗菌素的耐药性,分析细菌的质粒图谱,对耐药菌株进行质粒分子分型.结果 健康人肠道大肠埃希菌对四环素、萘啶酸、磺胺甲基异恶唑、氨苄西林、复方新诺明和链霉素的耐药率分别为63.33%、49.33%、40.67%、38.67%、35.33%、35.33%,全部菌株对头孢美唑和氨曲南敏感.122株菌(81.33%)耐一种以上抗菌素,88株菌(58.67%)耐2种以上抗菌素,44株菌(29.33%)耐5种以上抗菌素,2株菌耐10种抗菌素.结论 深圳市健康人肠道大肠埃希菌耐药性较严重,其耐药性与所携带质粒的数量和大小并无直接联系.

Antibiotic Resistance and Plasmid Profiles of Escherichia coli in Healthy Human Bodies

Objective To test the antibiotic resistance of 150 Escherichia coli strains isolated from the faeces of healthy people in Shenzhen city. Methods Escherichia coli were isolated and identified through a procedure described in the Microbiology in Preventive Medicine and Inspection Technique. The antimicrobial susceptibility of 150 isolates to 16 antibiotics was determined by the Kirby-Bauer method based on the Performance Standards for Anti-microbial Susceptibility Testing recommended by NCCLS. The plasmid profiles of the resistance strains were analyzed and classified. Results Over 35% of the tested strains showed resistance to 6 antibiotics, including Teracycline (63.33%), Nalidixic Acid (49.33%), Sulfamethoxazole (40.67%), Amplocilin (38.67%), Sulfamethoxazole timethoprim (35.33%), and Streptomycin (35.33%). All isolates were susceptible to Cefmelazon and Amikacin. More than 81% isolates resisted to at least one antibiotic, while 58.67% and 29.33% of the isolates resisted to more than 2 and 5 antibiotics respectively. Two strains showed resistance to 10 antibiotics. Conclusion Antibiotic resistance of Escherichia coli strains isolated from healthy people in Shenzhen city is common and serious. The number and size of plasmids in the isolates do not directly contribute to the antibiotic resistance.