神经外科住院患者定植及感染产毒艰难梭菌的分子流行病学特征

Molecular epidemiological characteristics of toxigenic Clostridium difficile colonization and infection in hospitalized patients of neurosurgery department

目的 研究神经外科住院患者定植及感染产毒艰难梭菌的分子流行病学特征。方法 采用前瞻性研究方法,选取2018年11月-2019年4月所有徐州医科大学附属医院神经外科新入院的成年患者161例为研究对象。在入院后48 h内、入院后每周及发生腹泻时分别采集粪便标本,本研究的主要临床结局是发生艰难梭菌感染(CDI),未发生CDI的患者随访至出院或死亡。对采集的粪便标本进行艰难梭菌培养及毒素基因检测,对所有的产毒艰难梭菌进行多位点序列分型。结果 从41名患者的粪便中培养分离出产毒艰难梭菌共计50株,其中,30株菌株tcdA及tcdB阳性,占60.00%;17株菌株仅tcdB阳性,占34.00%;3株菌株tcdA、tcdB及cdtA-cdtB均阳性,占6.00%。7名患者发生CDI,CDI发病率为4.35%,其中6名患者在入院时定植产毒艰难梭菌。将分离的50株产毒艰难梭菌进行多位点序列分型,共分析出14个ST分型,其中3株二元毒素阳性菌株均为ST5型。研究期间,患者4与患者31、患者13与患者19检测到相同的ST型,且居住过同一病房或床位。结论 本研究未分离到高毒力菌株ST1/RT027型或ST11/RT078型。研究期间存在产毒艰难梭菌定植患者传播艰难梭菌的可能,但有待进一步采用全基因组测序分型进行验证。

OBJECTIVE To explore the molecular epidemiological characteristics of toxigenic Clostridium difficile colonization and infection in hospitalized patients of neurosurgery department. METHODS By means of prospective study, a total of 161 adult patients who were just admitted to the neurosurgery department of the Affiliated Hospital of Xuzhou Medical University from Nov 2018 to Apr 2019 were enrolled in the study. The stool specimens were collected within 48 hours after admission, every week after admission and when the patients had diarrhea. The C.difficile infection, discharge and death of the patients without CDI were the major clinical outcomes. The stool specimens were cultured for C.difficile, toxin genes were detected, and multilocus sequence typing was carried out for all of the toxigenic C.difficile strains. RESULTS A total of 50 strains of toxigenic C.difficile were isolated from the stool specimens of 41 patients, 30(60.00%) strains were positive for tcdA and tcdB, 17(34.00%) were positive for tcdB, 3(6.00%) were positive for tcdA, tcdB and cdtA-cdtB. Totally 7 patients had CDI, with the morbidity rate 4.35%, 6 of whom were colonized with toxigenic C.difficile. The multilocus sequence typing was carried out for the 50 strains of toxigenic C.difficile, Totally 14 ST subtypes were identified, and all of the 3 strains of binary toxin-positive isolates were ST5 type. During the study, patient 4 and patient 31 shared the same ST type, patient 13 and patient 19 shared the same ST type, and they also shared the same ward or bed. CONCLUSION No strain of hypervirulent ST1/RT027 type or ST11/RT078 type is isolated in the study, it is possible that the C.difficile is transmitted via the patients colonized with toxigenic C.difficile, which, however, needs to be further verified by whole-genome sequencing.