长沙地区宋内志贺菌的耐药性及毒力基因分析

Antimicrobial resistance and virulence genes of Shigella sonnei in Changsha area

目的了解长沙地区宋内志贺菌对抗菌药物的敏感性以及毒力基因的携带情况。方法采用纸片扩散法检测30株宋内志贺菌对氨苄西林、头孢噻肟、萘啶酸、环丙沙星、庆大霉素、复方磺胺甲口恶唑6种抗菌药物的敏感性;聚合酶链反应(PCR)扩增4种毒力基因(与志贺菌肠毒素相关的set1、sen基因,以及与细菌侵袭性质粒有关的ial基因和ipaH基因)片段。结果在测定的6种抗菌药物中,耐药性最高的为氨苄西林、萘啶酸、复方磺胺甲口恶唑,耐药率均高达100%;而敏感性较高的为环丙沙星和庆大霉素,敏感率分别为93.33%和83.33%。30株宋内志贺菌经PCR检测后,set1、sen、ial、ipaH 4种毒力基因的携带率分别为0、13.33%、13.33%及53.33%。结论宋内志贺菌对第三代头孢菌素和磺胺类药物的耐药性已相当严重,第三代喹诺酮类药物可作为临床治疗宋内志贺菌的首选药物。长沙地区宋内志贺菌毒力基因携带率低。

Objective To investigate the antimicrobial susceptibility and the carrying of virulence genes of Shigella sonnei（S.sonnei）in Changsha area.Methods Susceptibilities of 30 S.sonnei strains to 6 kinds of antimicrobial agents（ampicillin,cefotaxime,nalidixic acid,ciprofloxacin,gentamicin,compound sulfamethoxazole）were detected by disc diffusion method;4 virulence genes（set1,sen,ial,ipaH）were amplified by polymerase chain reaction（PCR）.Results Of all detected antimicrobial agents,ampicillin,nalidixic acid and compound sulfamethoxazole had the highest resistance rate（100%）;while ciprofloxacin and gentamicin had higher susceptibility rate（93.33% and83.33% respectively）.PCR revealed that the carrying rate of set1,sen,ial and ipaHin30 S.sonnei strains was 0,13.33%,13.33% and 53.33% respectively.Conclusion Resistance of S.sonnei to the third-generation cefalosporins and sulfonamides are quite serious,third-generation quinolones can still be used as the first choice of drug treatment for S.sonnei infection.Carrying rate of virulence genes are low among S.sonnei in Changsha area.