为查明导致新疆南疆某规模化鹿场马鹿消瘦、腹泻并致其死亡的病因,通过临床检查与实验室检测分离病原菌,并从形态学与分子生物学进行鉴定。结果表明,分离得到1株副结核分支杆菌,该分离菌抗酸染色阳性,16 S rRNA基因与GenBank中多个副结...为查明导致新疆南疆某规模化鹿场马鹿消瘦、腹泻并致其死亡的病因,通过临床检查与实验室检测分离病原菌,并从形态学与分子生物学进行鉴定。结果表明,分离得到1株副结核分支杆菌,该分离菌抗酸染色阳性,16 S rRNA基因与GenBank中多个副结核分支杆菌序列同源性为100%,检测IS900基因与多个副结核分支杆菌序列同源性在99%以上,扩增亚型分型基因得到310 bp的片段,说明该菌株为Ⅱ型(牛型)副结核分支杆菌。最终确定引起该鹿场马鹿发病的病因为副结核分支杆菌感染,并首次成功分离培养出马鹿源副结核分枝杆菌。展开更多
AIM： To investigate overlapping regions of the rpoB gene previously involved with rifamycin resistance in M. tuberculosis and seek correlation between rpoB mutations in dinical MAP strains with susceptibility to RIF ...AIM： To investigate overlapping regions of the rpoB gene previously involved with rifamycin resistance in M. tuberculosis and seek correlation between rpoB mutations in dinical MAP strains with susceptibility to RIF and RFB. METHODS： We designed a molecular-based PCR method for the evaluation of rifabutin （RFB） and rifampicin （RIF） resistance based on probable determinant regions within the rpoB gene of MAP, including the 81 bp variable site located between nucleotides 1363 and 1443. The minimum inhibitory concentration （MIC） for RIF was also determined against 11 MAP isolates in attempt to seek correlation with rpoB sequences. RESULTS： We determined that MAP strain 18 had an MIC of 〉 30 mg/L and ≤ 5 mg/L for RIF and RFB respectively, and a significant and novel rpoB mutation C1367T, compared to an MIC of ≤ 1.0 mg/L for both drugs in the wild type MAP. The 30-fold increase in the MIC was a direct result of the rpoB mutation C1367T, which caused an amino acid change Thr456 to Ile456 in the drug＇s binding site. In addition, MAP strain 185 contained five silent rpoB mutations and exhibited an MIC comparable to the wild-type. Moreover, our in vitro selected mutation in MAP strain UCF5 resulted in the generation of a new resistant strain （UCF5-RIF16r） that possessed T1442C rpoB mutation and an MIC 〉 30 mg/L and 〉 10 mg/L for RIF and RFB respectively. Sequencing of the entire rpoB gene in MAP strains UCF4, 18, and UCF5-RIF16r revealed an rpoB mutation A2284C further downstream of the 81 bp variable region in UCF4, accounting for observed slight increase in MIC. In addition, no other significant mutations were found in strains 18 and UCF-RIF16r. CONCLUSION： The data clearly illustrates that clinical and in vitro-selected MAP mutants with rpoB mutations result in resistance to RIF and RFB, and that a single amino acid change in the beta subunit may have a significant impact on RIF resistance. Unconventional drug susceptibility testing such as our molecular approach will be beneficial for evaluation of antibiotic effectiveness. This molecular approach may also serve as a model for other drugs used for treatment of MAP infections.展开更多
0044108 内窥镜所见的一个 Jack-O’-灯笼/Hmnphrey M E//New Eng J Med.-1999,341(18).-1358 津医情0044109 旅游腹泻的定义、感染、治疗和预防[德,英摘]/Dller P C//Münch Med Wochenschr.-1999,141(9).-102～106同医图0044110 ...0044108 内窥镜所见的一个 Jack-O’-灯笼/Hmnphrey M E//New Eng J Med.-1999,341(18).-1358 津医情0044109 旅游腹泻的定义、感染、治疗和预防[德,英摘]/Dller P C//Münch Med Wochenschr.-1999,141(9).-102～106同医图0044110 尤并发症腹泻治疗的可能性[德,英摘]/Dobmeyer T S//Münch MedWochenschr.-1999,141(3).展开更多
文摘为查明导致新疆南疆某规模化鹿场马鹿消瘦、腹泻并致其死亡的病因,通过临床检查与实验室检测分离病原菌,并从形态学与分子生物学进行鉴定。结果表明,分离得到1株副结核分支杆菌,该分离菌抗酸染色阳性,16 S rRNA基因与GenBank中多个副结核分支杆菌序列同源性为100%,检测IS900基因与多个副结核分支杆菌序列同源性在99%以上,扩增亚型分型基因得到310 bp的片段,说明该菌株为Ⅱ型(牛型)副结核分支杆菌。最终确定引起该鹿场马鹿发病的病因为副结核分支杆菌感染,并首次成功分离培养出马鹿源副结核分枝杆菌。
基金Supported by Grant RO1-AI51251-01 from NIH-NIAID
文摘AIM： To investigate overlapping regions of the rpoB gene previously involved with rifamycin resistance in M. tuberculosis and seek correlation between rpoB mutations in dinical MAP strains with susceptibility to RIF and RFB. METHODS： We designed a molecular-based PCR method for the evaluation of rifabutin （RFB） and rifampicin （RIF） resistance based on probable determinant regions within the rpoB gene of MAP, including the 81 bp variable site located between nucleotides 1363 and 1443. The minimum inhibitory concentration （MIC） for RIF was also determined against 11 MAP isolates in attempt to seek correlation with rpoB sequences. RESULTS： We determined that MAP strain 18 had an MIC of 〉 30 mg/L and ≤ 5 mg/L for RIF and RFB respectively, and a significant and novel rpoB mutation C1367T, compared to an MIC of ≤ 1.0 mg/L for both drugs in the wild type MAP. The 30-fold increase in the MIC was a direct result of the rpoB mutation C1367T, which caused an amino acid change Thr456 to Ile456 in the drug＇s binding site. In addition, MAP strain 185 contained five silent rpoB mutations and exhibited an MIC comparable to the wild-type. Moreover, our in vitro selected mutation in MAP strain UCF5 resulted in the generation of a new resistant strain （UCF5-RIF16r） that possessed T1442C rpoB mutation and an MIC 〉 30 mg/L and 〉 10 mg/L for RIF and RFB respectively. Sequencing of the entire rpoB gene in MAP strains UCF4, 18, and UCF5-RIF16r revealed an rpoB mutation A2284C further downstream of the 81 bp variable region in UCF4, accounting for observed slight increase in MIC. In addition, no other significant mutations were found in strains 18 and UCF-RIF16r. CONCLUSION： The data clearly illustrates that clinical and in vitro-selected MAP mutants with rpoB mutations result in resistance to RIF and RFB, and that a single amino acid change in the beta subunit may have a significant impact on RIF resistance. Unconventional drug susceptibility testing such as our molecular approach will be beneficial for evaluation of antibiotic effectiveness. This molecular approach may also serve as a model for other drugs used for treatment of MAP infections.
文摘0044108 内窥镜所见的一个 Jack-O’-灯笼/Hmnphrey M E//New Eng J Med.-1999,341(18).-1358 津医情0044109 旅游腹泻的定义、感染、治疗和预防[德,英摘]/Dller P C//Münch Med Wochenschr.-1999,141(9).-102～106同医图0044110 尤并发症腹泻治疗的可能性[德,英摘]/Dobmeyer T S//Münch MedWochenschr.-1999,141(3).
