CAJ | 학술논문

目的研究儿童腹泻患者粪便分离的沙门菌属临床分离株的耐药特点及分子流行病学特征.方法从儿童腹泻患者粪便中分离沙门菌72株,采用血清学凝集试验确定沙门菌血清型;采用K-B纸片扩散法检测抗菌药物的敏感性;采用琼脂稀释法测定头孢噻肟(CTX)和头孢他啶(CAZ)的MIC值;ESBL、ISEcpI和AmpC基因采用PCR法和DNA测序法;采用接合试验测定耐药基因的转移性;PFGE法测定鼠伤寒沙门菌的同源性.结果从感染性腹泻患儿粪便中共分离出72株沙门菌,其中鼠伤寒沙门菌为主要血清型,占86%(62/72).鼠伤寒沙门菌和汤普森沙门菌通常对临床常用抗菌药物耐药.其中鼠伤寒沙门菌对氨苄西林的耐药率最高(90%,56/62),其次是四环素(81%,50/62),甲氧苄啶/磺胺甲基异(噁)唑(74%,46/62)和氯霉素(66%,41/62).17株(27%,17/62)鼠伤寒沙门菌和2株汤普森沙门菌对CTX耐药.对氨苄西林耐药的49株鼠伤寒沙门菌和2株汤普森沙门菌经PCR扩增后并测序为blaTEM-1b,62株鼠伤寒沙门菌中ESBL基因阳性的有13株(21%,13/62),且主要是blaCTX-M型,其中8株为blaCTX-M-14,3株为blaCTX-M-15,1株为blaCTX-M-55,另外1株为同时blaCTX-M-14和blaCTX-M-55阳性.所有blaCTX-M阳性的菌株均检测出存在上游的插入序列ISEcpl.在1株对头孢西丁耐药的汤普森沙门菌检测出blaDHA-1型AmpC.62株鼠伤寒沙门菌经PFGE分型,发现A型和D型是最主要两个克隆,分别占19%(12/62)和50%(31/62).7株产blaCTX-M型ESBL基因的菌株属于D型.结论鼠伤寒沙门菌和汤普森沙门菌耐药性严重且blaCTX-M型ESBL基因检出率高;在沙门菌属中发现blaCTX-M-55,在汤普森沙门菌中发现blaDHA-1°克隆性传播是造成鼠伤寒沙门菌流行的主要原因.
목적 연구인동복사환자분편분리적사문균속림상분리주적내약특점급분자류행병학특정.방법 종인동복사환자분편중분리사문균72주,채용혈청학응집시험학정사문균혈청형;채용K-B지편확산법검측항균약물적민감성;채용경지희석법측정두포새우(CTX)화두포타정(CAZ)적MIC치;ESBL、ISEcpI화AmpC기인채용PCR법화DNA측서법;채용접합시험측정내약기인적전이성;PFGE법측정서상한사문균적동원성.결과 종감염성복사환인분편중공분리출72주사문균,기중서상한사문균위주요혈청형,점86%(62/72).서상한사문균화탕보삼사문균통상대림상상용항균약물내약.기중서상한사문균대안변서림적내약솔최고(90%,56/62),기차시사배소(81%,50/62),갑양변정/광알갑기이(오)서(74%,46/62)화록매소(66%,41/62).17주(27%,17/62)서상한사문균화2주탕보삼사문균대CTX내약.대안변서림내약적49주서상한사문균화2주탕보삼사문균경PCR확증후병측서위blaTEM-1b,62주서상한사문균중ESBL기인양성적유13주(21%,13/62),차주요시blaCTX-M형,기중8주위blaCTX-M-14,3주위blaCTX-M-15,1주위blaCTX-M-55,령외1주위동시blaCTX-M-14화blaCTX-M-55양성.소유blaCTX-M양성적균주균검측출존재상유적삽입서렬ISEcpl.재1주대두포서정내약적탕보삼사문균검측출blaDHA-1형AmpC.62주서상한사문균경PFGE분형,발현A형화D형시최주요량개극륭,분별점19%(12/62)화50%(31/62).7주산blaCTX-M형ESBL기인적균주속우D형.결론 서상한사문균화탕보삼사문균내약성엄중차blaCTX-M형ESBL기인검출솔고;재사문균속중발현blaCTX-M-55,재탕보삼사문균중발현blaDHA-1°극륭성전파시조성서상한사문균류행적주요원인.
Objective To investigate molecular epidemiology and antimicrobial susceptibility of Salmonella spp. isolates recovered from the stool samples of children with diarrhea. Methods Seventy-two isolates of Salmonella spp. were collected from children with diarrhea. The serum type of Salmonella spp.was determined by serology agglutinating method. Antimicrobial susceptibility was determined by K-B disk diffusion method and MICs of cefotaxime and ceftazidime were measured by agar dilution method for Salmonella spp. isolates. PCR and DNA sequencing were used for detecting ESBL, ISEcpl and AmpC genes; The transfer of cefotaxime resistance was determined by conjugation experiments. PFGE was performed for determining the homogeneity of the S. typhimurium isolates. Results A total of 72 isolates of Salmonella spp. were collected, among which S. typhimurium accounted for 86 % (62/72) and was the main serum type. S. typhimurium isolates and S. thompson isolates were often resistant to most of clinically used antimicrobial agents. Resistance of S. thompson isolates to ampicillin was the highest (90%, 56/62),followed by tetracycline (81%, 50/62), trimethoprim/sulfamethoxazole (74%, 46/62) and chloramphenicol (66%, 41/62). Seventeen S. typhimurium isolates (27%, 17/62) and two S. thompson isolates were resistant to cefotaxime. Forty-nine S. typhimurium isolates and two S. thompson isolates were positive for blaTEB-1b and resistant to ampicillin. Thirteen ESBL-producing S. typhimurium isolates (21%, 13/62) were positive for blaCTX-M (eight for blaCTX-M-14, three for blaCTX-M-15, one for blaCTX-M-55, one for both blaCTX-M-14 and blaCTX-M-55). All isolates harboring blaCTX-M genes were positive for upstream insert sequence ISEcpl. blaDHA-1was detected in a cefoxitin-resistant S. thompson isolate. Two main clones (PFGE type A and D) accounting for 19% (12/62) and 50% (31/62) respectively were found among 62 S. typhimurium isolates. Seven CTXM-producing isolates belonged to PFGE type D. Conclusions The multi-resistance to antimicrobial agents and high prevalence of blaCTX-M genes are found among S. typhimurium and S. thompson clinical isolates. blaCTX-M-55 is first found in S. typhimurium isolates and blaDHA-1 is found in S. thompson isolates. Clonal spread is responsible for the dissemination of S. typhimurium isolates.