CAJ | 학술논문

目的了解临床分离黄杆菌(Chryseobacterium spp)耐药特性和金属β内酰胺酶(metallo-β-lactamase,MBL)的产酶率及其基因型.方法采用琼脂稀释法检测50株黄杆菌对18种抗生素的MIC,三纸片增效法、改良三维试验法进行MBL表型检测,PCR检测及序列分析确定MBL的基因型.接合试验检测耐药基因是否具有可转移性,等电聚焦电泳(IEF)测定β内酰胺酶等电点(pI).结果 50株黄杆菌对碳青霉烯类、氨基糖甙类及多种β内酰胺抗生素呈高度耐药,亚胺培南、美罗培南的耐药率均达82.0%,但利福平和喹诺酮类药物表现出很强的抗菌活性.表型检测33株细菌产MBL,产酶率为66.0%.MBL基因型分析结果,20株产吲哚黄杆菌携带bla IND,其中blaIND-1型9株、bla IND-2型10株、bla IND-LIKE型1株.14株脑膜炎败血黄杆菌中检出17种MBL基因,分别为blaB1 2株、blaB2 5株、blaB3 4株、blaB11 4株、bla GOB-1bla 1株;GOB-10 1株.接合试验均为阴性,质粒DNA未检出MBL基因.携带bla IND-1'的菌株(C-5)经IEF、MBL表型检测及β内酰胺酶初筛均为阴性.结论黄杆菌具有严重的多重耐药现象,同时具有很高的MBL检出率.bla B、bla GOB和bla IND可能位于黄杆菌染色体上,不能通过细菌质粒等可移动基因元件发生不同菌株和菌株间传播.bla IND-1可能存在蛋白质的不表达或低水平表达.
목적 료해림상분리황간균(Chryseobacterium spp)내약특성화금속β내선알매(metallo-β-lactamase,MBL)적산매솔급기기인형.방법 채용경지희석법검측50주황간균대18충항생소적MIC,삼지편증효법、개량삼유시험법진행MBL표형검측,PCR검측급서렬분석학정MBL적기인형.접합시험검측내약기인시부구유가전이성,등전취초전영(IEF)측정β내선알매등전점(pI).결과 50주황간균대탄청매희류、안기당대류급다충β내선알항생소정고도내약,아알배남、미라배남적내약솔균체82.0%,단리복평화규낙동류약물표현출흔강적항균활성.표형검측33주세균산MBL,산매솔위66.0%.MBL기인형분석결과,20주산신타황간균휴대bla IND,기중blaIND-1형9주、bla IND-2형10주、bla IND-LIKE형1주.14주뇌막염패혈황간균중검출17충MBL기인,분별위blaB1 2주、blaB2 5주、blaB3 4주、blaB11 4주、bla GOB-1bla 1주;GOB-10 1주.접합시험균위음성,질립DNA미검출MBL기인.휴대bla IND-1'적균주(C-5)경IEF、MBL표형검측급β내선알매초사균위음성.결론 황간균구유엄중적다중내약현상,동시구유흔고적MBL검출솔.bla B、bla GOB화bla IND가능위우황간균염색체상,불능통과세균질립등가이동기인원건발생불동균주화균주간전파.bla IND-1가능존재단백질적불표체혹저수평표체.
Objective To investigate the antibiotic resistance and the phenotype and genotype of metallo-β-lactamase in clinical isolates Chryseobacterium spp.Methods The MIC of 18 antibiotics in 50 Chryseobacterium spp.isolates was detected by agar dilution method.Phenotype of metallo-β-laetamase was detected by three-disc synergy test and modified three dimension test.Polymerase chain reaction(PCR)detection for metallo-β-lactamase gene was conducted for all isolates,and then the DNA sequence analysis was conducted for the PCR products which are positive for metallo-β-lactamase and identify genotype.conjugation experiment was used to study the transmission of metallo-β-lactamase encoding gene.pIs of β-lactamase was measured by isoelectric focusing assay. Results The antibiotic resistance of 50 clinical isolates of Chryseobacterium spp.against imipenem,Meropenem was 82.0%and 82.0%respectively.However,these isolated had high resistance to gatifloxacin.levofloxacin and rifampin compared with other antibiotics.Phenotype detection showed 33 isolated produced metallo-β-lactamase using three-disc synergy test and modified three dimension test,and the incidence of producing metallo-β-lactamase was 66.0%.Twenty isolateds producing Chryseobacterium indologenes were detected to have metallo-β-laetamase genotype by PCR amplification,among them 9 isolates containing blaIND-1 genotype and 10 isolateds containing blaIND-2 genotype.Strain CI-25 was identified to represent blaIND-LIKE genotype.Fourteen Chryseobacterium meningosepticum were detected to have metallo-β-lactamase genotype by PCR amplification,including 15 blaB and 2 blaGOB. The number of strain producing blaB1,blaB2,blaB3 and blaB11 in Chryseobacterium meningosepticum was 2,5,4 and 4,respectively. Conjugation experiments showed that metallo-β-lactamase encoding gene cannot be transfered. The extracted plasmid of 4 strains did not harbor metallo-β-lactamase gene.Strain C-5 was proved to have blaIND-1 gene,but its phenotype and IEF of metallo-β-lactamase was negative.Conclusions Chryseobacterium spp.had high frequency of multidrug resistance and high incidence for producing metallo-β-lactamase,and thus it was difficult to be treated.The gene of metallo-β-lactamase located on chromosome of Chryseobacterium spp.and cannot be transfered.There was negative or low lever of expression of blaIND-1.