新生儿粪便产超广谱β-内酰胺酶菌基因及耐药性分析

Analysis of gene and drug resistance of ESBL producing bacteria in neonatal feces

目的探讨新生儿粪便中产超广谱β-内酰胺酶(ESBL)菌产生途径,了解新生儿肠道产ESBL菌基因及耐药性。方法收集医院出生的健康新生儿及其母亲的粪便样本,应用选择性ESBL培养基进行细菌培养;培养阳性菌株应用飞行时间质谱仪进行菌种鉴定;全基因组测序技术进行ESBL基因型和耐药基因检测。结果 146份新生儿粪便标本,产ESBL菌阳性检出率8.90%,其中第1次排便产ESBL菌阳性检出率3.23%;出生72 h后粪便产ESBL菌阳性检出率为13.10%;13株产ESBL菌中CTX型9株,TEM型3株,SHV型1株;9株CTX型包括CTX-M-24、CTX-M-18、CTX-M-27、CTX-M-42和CTX-M-15五种型别。167份母亲粪便标本,产ESBL菌阳性检出率21.6%;ESBL基因型包括CTX型24株,TEM型6株,SHV型4株,Qnr S型2株;24株CTX型包括CTX-M-24、CTX-M-14、CTX-M-18、CTX-M-27、CTX-M-42和CTX-M-15。母婴共有12份标本检出2种或3种ESBL基因型。母婴49株产ESBL菌共检出aad A5、str A、str B、sul1、sul2和dfr A17等6种耐药基因;母婴同时检出产ESBL菌者,其耐药基因完全一致;7例新生儿和23例母亲粪便检出多种耐药基因。结论住院分娩新生儿在院期间可与母亲同时或单独在肠道检出产ESBL菌;新生儿肠道产ESBL菌产生途径有多种;产ESBL菌基因型和耐药基因种类较多。

Objectives To explore the route of ESBL producing bacteria in neonatal faeces,and to investigate the gene and drug resistance of ESBL producing bacteria in intestinal tract of neonates.Methods Fecal samples of healthy newborns and their mothers were collected,and bacterial cultures were carried out using selective ESBL medium.The positive strains were identified by Time-of-flight mass spectrometry.ESBL genotyping and resistance gene detection were performed by whole genome sequencing technique.Results In146neonatal fecal specimens,the positive rate of ESBL producing bacteria was8.90%,and the positive rate in the first time stool was3.23%.Seventy-two hours after birth,the positive rate of fecal ESBL producing bacteria was13.10%.Among the13ESBL producing strains,there were9strains of CTX type,3strains of TEM type and1strain of SHV type.Nine strains of CTX include five types such as CTX-M-24,CTX-M-18,CTX-M-27,CTX-M-42and CTX-M-15.The positive rate of ESBL producing bacteria was21.6%in167mothers'fecal specimens.The ESBL genotype included24strains of CTX type,6strains of TEM type,4strains of SHV type and2strains of QnrS type.Twenty-four strains of CTX include CTX-M-24,CTX-M-14,CTX-M-18,CTX-M-27,CTX-M-42and CTX-M-15.There were2or3ESBL genotypes in12maternal and neonatal specimens.It was detected to have6types of resistance gene such as aadA5,strA,strB,sul1,sul2and dfrA17in49strains of ESBL producing bacteria in maternal and neonatal strains.Resistance genes were exactly the same in the neonates as in mothers who were detected to have ESBL producing bacteria.A variety of resistance genes were detected in feces in7neonates and23mothers.Conclusions The neonates in hospital may be detected to have ESBL produing bacteria in the intestinal tract at the same time as their mothers or separately.However,there are many ways for neonates to have ESBL producing bacteria in intestinal tract.There are many genotypes and resistance genes of ESBL producing bacteria.