呼和浩特市89株肺炎链球菌携带耐药及毒力基因特征分析

Analysis on resistance genes and virulence genes of 89 Streptococcus pneumoniae strains in Hohhot

目的 探究呼和浩特地区住院患者分离肺炎链球菌抗生素耐药基因及携带毒力基因分布情况,了解儿童株和成人株之间的差异。方法 收集内蒙古医科大学附属医院2010年10月—2016年4月临床患者分离89株肺炎链球菌,采用PCR技术检测其携带耐药和毒力基因表达情况,分别统计分析其在儿童及成人分布不同。结果 89株肺炎链球菌耐药基因pbp2a、pacE阳性率为100%;pbp2b、pbp3、teM、ermB、gyrB和parC阳性率在90%以上;tetM、teO基因阳性率分别为51.7%、36.0%。pbp1a和tet基因在儿童分离株和成人分离株之间有差异(χ~2=5.107和22.984, P=0.01)。毒力基因stkP、nanA和piaA阳性率为100%;pcsB、phtD、pneumolysin、lytA、pspA和psaA基因阳性率均在90%以上;bacteriocin和clpP基因检测率较低,分别为79.8%和68.5%;cps2A基因在儿童株和成人株之间有差异(P=0.031)。结论 肺炎链球菌儿童分离株耐药基因携带率低于成人分离株,但毒力基因携带率明显高于成人分离株,不同人群肺炎链球菌菌分离株的生物学特征差异及其机制有待进一步研究。

Objective To investigate the distribution features of antibiotics resistance genes and virulence genes of Streptococcus pneumoniae strains isolated from inpatients in Hohhot,and to compare the differences of these genes between strains isolated from children and those from adults.Methods Streptococcus pneumoniae strains were isolated from inpatients hospitalized in the Affiliated Hospital of Inner Mongolia Medical University between October,2010 to April,2016,and PCR technique was used to detect the resistance genes and virulence genes.Results Among resistance genes detected,the positive rates of pbp2a and pacE were 100%(89/89),and those of pbp2b,pbp3,teM,ermB,gyrB and parC were higher than 90%.Moreover,the positive rates of tet and tetO were51.7%and 36.0%.The positive rates of pbp1a and tetD between children strains and adult strains were significantly different(χ2=5.107 and 22.984,P=0.01).Among the virulence genes detected,the positive rates of stkP,nanA and piaA were all 100%(89/89),and those of pcsB,phtD,pneumolysin,lytA,pspA and psaA were higher that 90%.The positive rates of bacteriocin and clpP were lower,which were 79.8%and 68.5%,respectively.The positive rates of cps2A between children strains and adult strains was significantly different(P=0.01).Conclusion The total positive rate of resistance genes of Streptococcus pneumoniae strains isolated from children was lower than that from adults,while the total virulence genes of strains isolated from children was higher than that from adults.The difference features and possible mechanism of Streptococcus pneumoniae strains among different groups of patients deserves to be further investigated.