副伤寒沙门菌耐药性与菌株质粒的监测

Surveillance on antibiotic resistance and plasmid of salmonella paratyphoid

目的 了解副伤寒沙门菌的耐药情况及耐药机制。方法 对 1 997～ 2 0 0 1年从桂林地区分离到的 2 92株副伤寒沙门菌进行药敏实验和质粒检测。结果 2 92株副伤寒沙门菌对痢特灵、头孢氨苄、头孢唑啉、头孢啦定敏感率达 1 0 0 % ,对复方新诺明的耐药率为 80 .0 % ,磺胺甲基异口恶唑 85 .6 % ,对此两种抗生素的耐药性有逐年增高的趋势。菌株多重耐药最多可达 4～ 6种 ,耐药类型以磺胺甲基异口恶唑、复方新诺明、青霉素、红霉素为主。 85 .6 % (2 5 0 / 2 92 )的菌株可检出带有90Mdal的大分子质粒 ,质粒检出率与耐药种类呈正相关 (t=4 .78,P <0 .0 5 ) ,所有耐磺胺甲基异口恶唑和复方新诺明的菌株均能检出该质粒 ,而 2 9株敏感株则未能检出质粒。结论 桂林地区副伤寒杆菌普遍对磺胺甲基异口恶唑和复方新诺明耐药 ,痢特灵、头孢氨苄、头孢唑啉、头孢啦定等抗菌素为桂林地区治疗副伤寒的首选药物。菌株携带 90Mdal大分子质粒 ,与副伤寒菌株的耐药性有关。

Objective To study the antibiotic resistance and its mechanism of salmonella paratyphoid. Methods Antibiotic susceptibility test and plasmid detection were carried out for 292 strains of salmonella paratyphoid isolated in Guilin area during 1997～2001. Results Susceptibility rate of 292 strains of salmonella paratyphoid to furazolidone, cefalexin, cefazolin, cefradine was 100%, resistance rate to sulfarmethoxazole/trimethoprim and sulfarmethoxazole was 80.0% and 85.6%, respectively. The strains were resistant to 4～6 antibiotics. The resistant types of strains were mainly four antibiotics SMX, SXT, P and E. The plasmid detection showed that 85.6% (250/292) of strains were mediated by a large plasmid of 90 Mdal. There was positive correlation between plasmid positive rate and resistant types of strains (t=4.78,P<0.05). A large plasmid of 90 Mdal could be detected among all strains resistant to sulfarmethoxazole/trimethoprim and sulfarmethoxazole, but negative among 29 sensitive strains. Conclusions The strains of salmonella paratyphoid isolated in Guilin area were generally resistant to sulfarmethoxazole/trimethoprim and sulfarmethoxazole. Furazolidone, cefalexin, cefazolin, cefradine could be selected first to cure the paratyphoid fever. Plasmid positive was correlative with antibiotic resistance of strains.