摘要
目的研究新生儿下呼吸道流感嗜血杆菌(Haemophilus influenzae,Hi)分离株β-内酰胺类抗生素耐药趋势变化与分子耐药机制。方法对19株新生儿Hi分离株进行再鉴定,通过PCR法测菌株P6、fucK和Cap基因进行血清学分型,用肉汤微量稀释法检测氨苄西林、阿莫西林克拉维酸和头孢呋辛最低抑菌浓度(minimum inhibitory concentration,MIC);对TEM-1、ROB-1和ftsI基因进行测序和变异分析。结果(1)19株Hi经P6、fucK和Cap基因检测证实均为无荚膜型,即不可分型流感嗜血杆菌(non-typeable Haemophilus influenzae,NTHi)。(2)与2003至2004年比较,2013至2014年新生儿下呼吸道NTHi分离株氨苄西林、阿莫西林克拉维酸和头孢呋辛的MIC值明显增高,差异有统计学意义(P<0.05)。(3)2003至2004年(n=9)和2013至2014年(n=10)产β-内酰胺酶菌株均为3株,10年间比较差异无统计学意义(P>0.05);BLA基因检测显示6株产β-内酰胺酶均为TEM-1型,未检测出ROB-1型菌株。(4)2003至2004年仅出现1株基因型β-内酰胺酶阳性氨苄西林耐药(gBLPAR),2013至2014年出现基因型β-内酰胺酶阴性氨苄西林耐药(gBLNAR)1株、基因型β-内酰胺酶阴性氨苄西林中介(gBLNAI)3株、gBLPAR 3株、基因型β-内酰胺酶阳性阿莫西林克拉维酸耐药(gBLPACR)1株。(5)2013至2014年ftsI基因出现了11个氨基酸替代模式,而2003至2004年仅出现5个氨基酸替代模式;10年间比较ftsI基因S357N、S385T、N526K、T532S变异率显著增加,差异有统计学意义(P<0.05)。1株2014年分离的耐氨苄西林、阿莫西林克拉维酸和头孢呋辛的gBLNAR/gBLNACR菌株同时出现D350N、S357N、M377I、S385T、L389F、A502T、N526K变异。结论新生儿下呼吸道NTHi感染患儿或将迅速面临β-内酰胺类抗生素多重耐药的严峻挑战。
Objective To study the changes ofβ-lactam resistance of Haemophilus influenzae(Hi)strain isolated from neonatal lower respiratory tract and the molecular mechanism ofβ-lactam resistance.Methods Nineteen Hi strains isolated from neonatal lower respiratory tract infection in the previous multicenter prospective epidemiological study were re-identified,and the P6,fucK and Cap genes were detected by PCR.The minimum inhibitory concentration(MIC)of ampicillin,amoxicillin clavulanic acid and cefuroxime were detected by microdilution method,and tem-1 gene,rob-1 gene and ftsI gene were sequenced and analyzed.Results(1)Nineteen strains of Hi were confirmed to be capsule-free type by P6 gene,fucK gene and cap gene,which was non-typeable Haemophilus influenzae(NTHi).(2)Compared with 2003-2004,the MIC values of ampicillin,amoxicillin clavulanic acid and cefuroxime of NTHi isolated from the lower respiratory tract of the newborn from 2013-2014 were significantly higher(P<0.05).(3)The rates ofβ-lactamase producing strains during 2003-2004 and 2013-2014 were 33.33%(3/9)and 30.00%(3/10),respectively.There was no significant difference between them during 10 years(P>0.05).The detection of theβ-lactamase gene showed that theβ-lactamase of the all six strains were of the tem-1 type,and the rob-1 type was not detected.(4)Only one gBLNAR strain(n=9)was found during 2003~2004,and gBLNAR 1,gBLNAI 3,gBLPAR 3,gBLPACR 1(n=10)appeared during 2013~2014.(5)There were 11 amino acid substitution patterns in ftsI gene during 2013~2014,but only five amino acid substitution patterns in 2003~2004.The mutation rate of the S357N,S385T,N526K and T532S of ftsI gene significantly increased during the past ten years(P<0.05).One strain of gBLNAR/gBLNACR resistant to ampicillin,amoxicillin clavulanic acid and cefuroxime isolated in 2014 showed D350N,S357N,M377I,S385T,L389F,A502T and N526K variation at the same time.Conclusion Neonatal patients with lower respiratory tract NTHi infection may rapidly face the severe challenge of multiple drug resistance ofβ-lactam antibiotics.
作者
王晓蕾
王战豪
郭慧敏
张彤
李桦
谢江
胡俊
Wang Xiaolei;Wang Zhanhao;Guo Huimin;Zhang Tong;Li Hua;Xie Jiang;Hu Jun(Department of Paediatrics,Affiliated Hospital of South West Jiao Tong University&the Third People′s Hospital of Chengdu,Chengdu 610031,China;Department of Laboratory Medicine,Affiliated Hospital of South West Jiao Tong University&the Third People′s Hospital of Chengdu,Chengdu 610031,China;Department of Information,Affiliated Hospital of South West Jiao Tong University&the Third People′s Hospital of Chengdu,Chengdu 610031,China)
出处
《中国小儿急救医学》
CAS
2020年第7期531-535,共5页
Chinese Pediatric Emergency Medicine
基金
四川省科技厅应用基础研究项目(2013JY0121)
成都市科技惠民项目(HM01-00272-SF)。
