中华微生物学和免疫学杂志
中華微生物學和免疫學雜誌
중화미생물학화면역학잡지
CHINESE JOURNAL OF MICROBIOLOGY AND IMMUNOLOGY
2014年
1期
23-28
,共6页
张晓蕾%邹安庆%张亚培%叶建中%马传玲%周铁丽%曹建明
張曉蕾%鄒安慶%張亞培%葉建中%馬傳玲%週鐵麗%曹建明
장효뢰%추안경%장아배%협건중%마전령%주철려%조건명
摩根摩根菌%qnrD基因%氟喹诺酮%质粒
摩根摩根菌%qnrD基因%氟喹諾酮%質粒
마근마근균%qnrD기인%불규낙동%질립
Morganella morganii%qnrD gene%Fluoroquinolones%Plasmid
目的 分析摩根摩根菌中qnrD基因的流行分布及所在质粒大小.方法 收集临床分离摩根摩根菌共100株,琼脂稀释法测定氟喹诺酮类药物对其最低抑菌浓度(mininal inhibotory concentrations,MICs)值,以PCR检测qnrD基因及其他质粒介导的喹诺酮耐药(plasmid-mediated quinolone resistance,PMQR)基因,同时检测PMQR基因阳性菌株中超广谱β-内酰胺酶基因(extended-spectrum β-lactamases,ESBLs)和AmpC酶基因,采用PFGE分析qnrD基因阳性菌株间的同源性,Southern杂交方法对qnrD基因进行定位并确定所在质粒的大小,接合转移试验检测qnrD基因的可转移性.结果 PCR检测及测序发现30株(30％)摩根摩根菌携带PMQR基因,包括17株qnrD基因阳性菌株,14株aac(6')-Ib-cr基因阳性菌株,5株qepA阳性菌,几乎所有PMQR基因阳性菌对氟喹诺酮类药物表现为敏感性降低,PCR检测及测序确认30株菌均携带blaDHA-1,6株携带ESBLs基因(4株携带blaCTX-M-14,1株携带blaCTX-M-3,l株携带blaCTX-M-24型ESBLs),4株携带blaTEM-1β-内酰胺酶基因,17株qnrD基因阳性菌株中,5株菌(29.4％)同时携带aac(6')-Ib-cr基因,分别有4株(23.5％)和2株(11.8％)菌同时携带blaCTX-M-14和blaTEM-1,1株qnrD基因菌株同时携带aac(6')-ib-cr基因,blaCTX-M-14和blaDHA.1.PFGE结果显示17株qnrD基因阳性菌没有同源性,Southern杂交结果显示所有菌株的qnrD基因均定位于质粒,其质粒大小主要为2.7 kb,少部分菌株的qnrD基因可能同时位于5.1 kb大小的质粒,多次接合转移试验均未成功获得携带qnrD基因的接合子.结论 本研究摩根摩根菌中PMQR基因分布广泛,qnrD基因最为流行,其次是aac(6')-ib-cr基因,本研究摩根摩根菌中qnrD基因携带率高达17.0％,基因定位确认该基因主要位于2.7 kb大小的不易转移的质粒,同时也可能位于5.1 kb大小的质粒,本研究发现1株同时携带qnrD、aac(6')-lb-cr、blaCTX-M-14和blaDHA-1基因的摩根摩根菌.
目的 分析摩根摩根菌中qnrD基因的流行分佈及所在質粒大小.方法 收集臨床分離摩根摩根菌共100株,瓊脂稀釋法測定氟喹諾酮類藥物對其最低抑菌濃度(mininal inhibotory concentrations,MICs)值,以PCR檢測qnrD基因及其他質粒介導的喹諾酮耐藥(plasmid-mediated quinolone resistance,PMQR)基因,同時檢測PMQR基因暘性菌株中超廣譜β-內酰胺酶基因(extended-spectrum β-lactamases,ESBLs)和AmpC酶基因,採用PFGE分析qnrD基因暘性菌株間的同源性,Southern雜交方法對qnrD基因進行定位併確定所在質粒的大小,接閤轉移試驗檢測qnrD基因的可轉移性.結果 PCR檢測及測序髮現30株(30％)摩根摩根菌攜帶PMQR基因,包括17株qnrD基因暘性菌株,14株aac(6')-Ib-cr基因暘性菌株,5株qepA暘性菌,幾乎所有PMQR基因暘性菌對氟喹諾酮類藥物錶現為敏感性降低,PCR檢測及測序確認30株菌均攜帶blaDHA-1,6株攜帶ESBLs基因(4株攜帶blaCTX-M-14,1株攜帶blaCTX-M-3,l株攜帶blaCTX-M-24型ESBLs),4株攜帶blaTEM-1β-內酰胺酶基因,17株qnrD基因暘性菌株中,5株菌(29.4％)同時攜帶aac(6')-Ib-cr基因,分彆有4株(23.5％)和2株(11.8％)菌同時攜帶blaCTX-M-14和blaTEM-1,1株qnrD基因菌株同時攜帶aac(6')-ib-cr基因,blaCTX-M-14和blaDHA.1.PFGE結果顯示17株qnrD基因暘性菌沒有同源性,Southern雜交結果顯示所有菌株的qnrD基因均定位于質粒,其質粒大小主要為2.7 kb,少部分菌株的qnrD基因可能同時位于5.1 kb大小的質粒,多次接閤轉移試驗均未成功穫得攜帶qnrD基因的接閤子.結論 本研究摩根摩根菌中PMQR基因分佈廣汎,qnrD基因最為流行,其次是aac(6')-ib-cr基因,本研究摩根摩根菌中qnrD基因攜帶率高達17.0％,基因定位確認該基因主要位于2.7 kb大小的不易轉移的質粒,同時也可能位于5.1 kb大小的質粒,本研究髮現1株同時攜帶qnrD、aac(6')-lb-cr、blaCTX-M-14和blaDHA-1基因的摩根摩根菌.
목적 분석마근마근균중qnrD기인적류행분포급소재질립대소.방법 수집림상분리마근마근균공100주,경지희석법측정불규낙동류약물대기최저억균농도(mininal inhibotory concentrations,MICs)치,이PCR검측qnrD기인급기타질립개도적규낙동내약(plasmid-mediated quinolone resistance,PMQR)기인,동시검측PMQR기인양성균주중초엄보β-내선알매기인(extended-spectrum β-lactamases,ESBLs)화AmpC매기인,채용PFGE분석qnrD기인양성균주간적동원성,Southern잡교방법대qnrD기인진행정위병학정소재질립적대소,접합전이시험검측qnrD기인적가전이성.결과 PCR검측급측서발현30주(30％)마근마근균휴대PMQR기인,포괄17주qnrD기인양성균주,14주aac(6')-Ib-cr기인양성균주,5주qepA양성균,궤호소유PMQR기인양성균대불규낙동류약물표현위민감성강저,PCR검측급측서학인30주균균휴대blaDHA-1,6주휴대ESBLs기인(4주휴대blaCTX-M-14,1주휴대blaCTX-M-3,l주휴대blaCTX-M-24형ESBLs),4주휴대blaTEM-1β-내선알매기인,17주qnrD기인양성균주중,5주균(29.4％)동시휴대aac(6')-Ib-cr기인,분별유4주(23.5％)화2주(11.8％)균동시휴대blaCTX-M-14화blaTEM-1,1주qnrD기인균주동시휴대aac(6')-ib-cr기인,blaCTX-M-14화blaDHA.1.PFGE결과현시17주qnrD기인양성균몰유동원성,Southern잡교결과현시소유균주적qnrD기인균정위우질립,기질립대소주요위2.7 kb,소부분균주적qnrD기인가능동시위우5.1 kb대소적질립,다차접합전이시험균미성공획득휴대qnrD기인적접합자.결론 본연구마근마근균중PMQR기인분포엄범,qnrD기인최위류행,기차시aac(6')-ib-cr기인,본연구마근마근균중qnrD기인휴대솔고체17.0％,기인정위학인해기인주요위우2.7 kb대소적불역전이적질립,동시야가능위우5.1 kb대소적질립,본연구발현1주동시휴대qnrD、aac(6')-lb-cr、blaCTX-M-14화blaDHA-1기인적마근마근균.
Objective To investigate the prevalence and plasmid size of qnrD determinant in Morganella morganii (M.morganii) isolates.Methods A total of 100 non-duplicated M.morganii clinical isolates were collected from inpatients.Standard ager dilution method was used to determine the minimum inhibitory concentrations (MICs) of fluoroquinolones against M.morganii isolates.PCR were performed to detect plasmid-mediated quinolone resistance determinants (PMQRs) in M.morganii isolates and the prevalence of extended-spectrum β-lactamase (ESBL) genes and AmpC β-lactamase genes in PMQRs-positive M.morganii strains.The homology analysis among qnrD-positive M.morganii strains were conducted by using pulsed-field gel electrophoresis (PFGE).The location of qnrD gene and the size of plasmid carrying it were determined by southern hybridization.The transferability of qnrD gene was determined by conjugation experiment.Results Thirty out of 100 M.morganii isolates (30％) were found carrying PMQRs including 17 qnrD-positive strains,14 aac (6')-Ib-cr-positive strains and 5 qepA-positive strains.PCR and sequencing confirmed that thirty PMQRs-positive isolates carried blaDHA-1.Among them,six isolates were positive for ESBLs genes (four for blaCTX-M-14,one for blaCTX-M-3 and one for blaCTX-M-24) and four isolates were positive for blaTEM-1.Almost all PMQRs-positive M.morganii isolates showed reduced susceptibility to fluoroquinolones.Moreover,seventeen qnrD-positive M.morganii isolates harbored blaDHA-1 including five (29.4％) harboring aac(6')-Ib-cr gene,four (23.5％) harboring blaCTX-M-14,two (11.8％) harboring blaTEM-1 and one harboring aac(6')-Ib-cr gene,blaCTX-M-14 and blaDHA-1.PFGE analysis showed that the 17 qnrD-positive M.morganii isolates were divergent from each other and not clone-related.Southern hybridization analysis showed that qnrD genes of all M.morganiiis isolates were mainly located in a 2.7 kb plasmid,but only a few of them were located in a size of 5.1 kb plasmid.M.morganiiis isolates failed to transfer qnrD gene to E.coli EC600 through conjugation.Conclusion PMQRs were widely distributed in M.morganiiis isolates.qnrD gene was the predominant determinants with a high prevalence rate of 17.0％,followed by aac(6')-Ib-cr gene.qnrD gene was located on a non-conjugative plasmid of approximately 2.7 kb or 5.1 kb.One qnrD-positive M.morganii isolate carrying aac(6')-Ib-cr gene,blaCTX-M-14 and blaDHA-1 was detected.
