中国感染与化疗杂志
中國感染與化療雜誌
중국감염여화료잡지
CHINESE JOURNAL OF INFECTION AND CHEMOTHERAPY
2013年
6期
456-459
,共4页
李瑞华%刘亮%聂大平%曲杰
李瑞華%劉亮%聶大平%麯傑
리서화%류량%섭대평%곡걸
oqxAB 基因%质粒%接合子%大肠埃希菌%肺炎克雷伯菌
oqxAB 基因%質粒%接閤子%大腸埃希菌%肺炎剋雷伯菌
oqxAB 기인%질립%접합자%대장애희균%폐염극뢰백균
oqxAB gene%plasmid%conjugant%Escherichia coli%Klebsiella pneumoniae
目的：了解大肠埃希菌和肺炎克雷伯菌中 oqxAB 基因的流行情况和传播。方法收集72株大肠埃希菌和49株肺炎克雷伯菌。用 PCR 扩增 oqxAB 基因，接合试验验证 oqxAB 是否存在于质粒上。琼脂稀释法测定环丙沙星对含 oqxAB 基因接合子 MIC 和防耐药突变浓度（MPC）。结果72株大肠埃希菌 oqxA、oqxB 和 oqxAB 基因阳性分别为15株（15/72）、4株（4/72）和7株（7/72），49株肺炎克雷伯菌分别为4株（4/49）、1株（1/49）和34株（34/49）。大肠埃希菌环丙沙星敏感和耐药株中 oqxAB 基因阳性分别为2株（2/16）和5株（5/56），肺炎克雷伯菌分别为8株（8/14）和26株（26/35）。含与不含 oqx-AB 基因大肠埃希菌和肺炎克雷伯菌对喹诺酮类抗菌药物敏感率差异无统计学意义。大肠埃希菌和肺炎克雷伯菌 PCR 扩增产物序列与 GenBank 中 oqxAB 基因登录号 AB601773．1和 FJ975561．1符合率均为99％。大肠埃希菌质粒接合试验中有4株接合成功，环丙沙星对接合子 MIC 为0．25～0．5 mg/L，较受体菌提高31～62倍。环丙沙星对接合子 MPC 为8～16 mg/L，较受体菌 J53高32倍。肺炎克雷伯菌质粒接合没有成功。环丙沙星对肺炎克雷伯菌 MIC≤0．0625 mg/L，无论是否含 oqxAB 基因，MPC 为0．25～0．5 mg/L；但 MIC 为0．25～0．5 mg/L 时，无论是否含 oqxAB 基因，MPC 为2～16 mg/L。结论oqxAB 基因存在于大肠埃希菌和肺炎克雷伯菌中，该基因在大肠埃希菌通过质粒传播，oqxAB 基因在环丙沙星耐药和敏感株中检出率差异无统计学意义，表明其介导细菌对环丙沙星是低水平耐药。含 oqxAB 基因的接合子在喹诺酮类压力选择下能产生高水平耐药。肺炎克雷伯菌在环丙沙星压力下产生高水平耐药与 oqxAB 基因无关，而与其 MIC 有关。
目的：瞭解大腸埃希菌和肺炎剋雷伯菌中 oqxAB 基因的流行情況和傳播。方法收集72株大腸埃希菌和49株肺炎剋雷伯菌。用 PCR 擴增 oqxAB 基因，接閤試驗驗證 oqxAB 是否存在于質粒上。瓊脂稀釋法測定環丙沙星對含 oqxAB 基因接閤子 MIC 和防耐藥突變濃度（MPC）。結果72株大腸埃希菌 oqxA、oqxB 和 oqxAB 基因暘性分彆為15株（15/72）、4株（4/72）和7株（7/72），49株肺炎剋雷伯菌分彆為4株（4/49）、1株（1/49）和34株（34/49）。大腸埃希菌環丙沙星敏感和耐藥株中 oqxAB 基因暘性分彆為2株（2/16）和5株（5/56），肺炎剋雷伯菌分彆為8株（8/14）和26株（26/35）。含與不含 oqx-AB 基因大腸埃希菌和肺炎剋雷伯菌對喹諾酮類抗菌藥物敏感率差異無統計學意義。大腸埃希菌和肺炎剋雷伯菌 PCR 擴增產物序列與 GenBank 中 oqxAB 基因登錄號 AB601773．1和 FJ975561．1符閤率均為99％。大腸埃希菌質粒接閤試驗中有4株接閤成功，環丙沙星對接閤子 MIC 為0．25～0．5 mg/L，較受體菌提高31～62倍。環丙沙星對接閤子 MPC 為8～16 mg/L，較受體菌 J53高32倍。肺炎剋雷伯菌質粒接閤沒有成功。環丙沙星對肺炎剋雷伯菌 MIC≤0．0625 mg/L，無論是否含 oqxAB 基因，MPC 為0．25～0．5 mg/L；但 MIC 為0．25～0．5 mg/L 時，無論是否含 oqxAB 基因，MPC 為2～16 mg/L。結論oqxAB 基因存在于大腸埃希菌和肺炎剋雷伯菌中，該基因在大腸埃希菌通過質粒傳播，oqxAB 基因在環丙沙星耐藥和敏感株中檢齣率差異無統計學意義，錶明其介導細菌對環丙沙星是低水平耐藥。含 oqxAB 基因的接閤子在喹諾酮類壓力選擇下能產生高水平耐藥。肺炎剋雷伯菌在環丙沙星壓力下產生高水平耐藥與 oqxAB 基因無關，而與其 MIC 有關。
목적：료해대장애희균화폐염극뢰백균중 oqxAB 기인적류행정황화전파。방법수집72주대장애희균화49주폐염극뢰백균。용 PCR 확증 oqxAB 기인，접합시험험증 oqxAB 시부존재우질립상。경지희석법측정배병사성대함 oqxAB 기인접합자 MIC 화방내약돌변농도（MPC）。결과72주대장애희균 oqxA、oqxB 화 oqxAB 기인양성분별위15주（15/72）、4주（4/72）화7주（7/72），49주폐염극뢰백균분별위4주（4/49）、1주（1/49）화34주（34/49）。대장애희균배병사성민감화내약주중 oqxAB 기인양성분별위2주（2/16）화5주（5/56），폐염극뢰백균분별위8주（8/14）화26주（26/35）。함여불함 oqx-AB 기인대장애희균화폐염극뢰백균대규낙동류항균약물민감솔차이무통계학의의。대장애희균화폐염극뢰백균 PCR 확증산물서렬여 GenBank 중 oqxAB 기인등록호 AB601773．1화 FJ975561．1부합솔균위99％。대장애희균질립접합시험중유4주접합성공，배병사성대접합자 MIC 위0．25～0．5 mg/L，교수체균제고31～62배。배병사성대접합자 MPC 위8～16 mg/L，교수체균 J53고32배。폐염극뢰백균질립접합몰유성공。배병사성대폐염극뢰백균 MIC≤0．0625 mg/L，무론시부함 oqxAB 기인，MPC 위0．25～0．5 mg/L；단 MIC 위0．25～0．5 mg/L 시，무론시부함 oqxAB 기인，MPC 위2～16 mg/L。결론oqxAB 기인존재우대장애희균화폐염극뢰백균중，해기인재대장애희균통과질립전파，oqxAB 기인재배병사성내약화민감주중검출솔차이무통계학의의，표명기개도세균대배병사성시저수평내약。함 oqxAB 기인적접합자재규낙동류압력선택하능산생고수평내약。폐염극뢰백균재배병사성압력하산생고수평내약여 oqxAB 기인무관，이여기 MIC 유관。
Objective To investigate the prevalence and the transmission of oqxAB gene in clinical strains of Escherichia coli and Klebsiella pneumoniae .Methods Nonduplicate clinical isolates of E.coli (n=72)and K .pneumoniae (n=49)were col-lected.The oqxAB gene was amplified by PCR.The product was sequenced.Plasmid conjugation experiments were done in oqxAB-positive E.coli and K.pneumoniae strains to detemine whether oqxAB gene is located in plasmid.The MICs and mu-tant prevention concentrations (MPCs)for ciprofloxacin were determined in transconjugants with oqxAB gene by agar dilution method.Results The oqxA,oqxB and oqxAB were identified in 15,4,and 7 of the 72 strains of Escherichia coli and 4,1,and 34 of the 49 strains of K.pneumoniae,respectively.The oqxAB gene was positive in 2 (2/16)ciprofloxacin sensitive and 5 (5/56)ciprofloxacin resistant E.coli strains,in 8 (8/14)ciprofloxacin sensitive and 26 (26/35)ciprofloxacin resistant K. pneumoniae strains,respectively.The E.coli and K.pneumoniae strains with or without oqxAB did not show different sus-ceptibility to ciprofloxacin.The oqxA and oqxB sequences from E.coli and K.pneumoniae showed 99% similarity to the se-quences of GeneBank accession number AB601773.1 and accession number FJ975561.1,respectively.The oqxAB gene was successfully transferred in 4 of the 5 oqxAB-positive E.coli strains.The MIC of ciprofloxacin was 0.25-0.5 mg/L against the transconjugants,31-62 times higher than the MICs for the recipient strains.The MPC of ciprofloxacin was 8-16 mg/L against the transconjugants,32 times higher than that for recipient strain J53.The oqxAB gene were not transferred in K. pneumoniae. When the MIC of ciprofloxacin was ≤0.062 5 mg/L,the MPC of ciprofloxacin was 0.25-0.5 mg/L for K.pneumoniae strains with or without oqxAB.When MIC was 0.25-0.5 mg/L,the MPC of ciprofloxacin was 2-16 mg/L for K .pneumoniae strains with or without oqxAB .Conclusions oqxAB gene is present in E .coli and K .pneumoni-ae .The oqxAB gene spreads through plasmid in E .coli.The nonsiginificant difference of oqxAB prevalence between ciproflox-acin sensitive and ciprofloxacin resistant strains indicates that oqxAB gene may mediate low level resistance to ciprofloxacin in E.coli.The E.coli transconjugants of oqxAB gene can produce high level resistance under the selection pressure of ciproflox-acin.The high level resistance in K .pneumoniae under selection pressure of ciprofloxacin is not associated with oqxAB gene, but related to the ciprofloxacin MIC against these strains.
