The clinical application of identification of Aspergillus spp.using ITS and β-tubulin gene sequences

Objective To study the clinical application of the ITS and β-tubulin gene regions in identification of Aspergillus spp. Methods One hundred and twenty-four Aspergillus strains that isolated from fungal rhino-sinusitis specimens were collected in Beijing Tongren Hospital, Capital Medical University from July 2007 to January 2010. They were identified by morphological and molecular methods. The first one included traditional culture, slide culture, and microscopic examination after lactophenol cotton blue stain and KOH digestion. The second one was amplifying and sequencing the part of ITS and β-tubulin gene and aligned all the sequences in the GenBank, European Molecular Biology Laboratory nucleotide sequence database, and DNA Data Bank of Japan. Results Of the 56 Aspergillus flavus identified by morphological features, fifty-five isolates were identified as Aspergillus flavus and 1 isolates was Aspergillus parasiticus by the ITS and β-tubulin gene region sequence analysis. In the 37 Aspergillus fumigatus identified by morphological method, and all the 37 isolates were identified as species complex of Aspergillus fumigatus by the ITS region sequence analysis, but through the sequence analysis of β-tubulin gene region, thirty-five isolates were identified as Aspergillus. fumigatus and 2 were Aspergillus lentulus. Twenty-one isolates were identified as Aspergillus versicolor by morphological method, but 16 of them were identified as Aspergillus. versicolor and 5 can not be identified to species level by the ITS region sequence. And by comparative-sequence analysis of β-tubulin gene region, the 5 isolates were identified as Aspergillus sydowii,the other 16 isolates were Aspergillus. versilcolor. Ten isolates were identified as Aspergillus nidulans by morphological features, the ITS and β-tubulin gene region sequence analysis. Conclusions β-tubulin gene sequencing is more suitable for identifying Aspergillus, and could identify Aspergillus spp. to species level Sequences of ITS region could only identify Aspergillus spp. to species complex.     

ITS和β-微管蛋白基因序列鉴定曲霉菌的临床应用

目的 研究ITS序列分析和β-微管蛋白基因序列分析在曲霉菌鉴定中的临床应用价值.方法 收集2007年7月至2010年1月,首都医科大学附属北京同仁医院真菌性鼻窦炎病原菌株中曲霉菌124株,分别对其进行形态学和分子鉴定.形态学包括传统培养方法、玻片培养和乳酸酚棉蓝染色及KOH消化后显微镜镜检.将菌株的PCR扩增产物进行ITS序列分析和β-微管蛋白基因序列分析,其测序结果与GenBank、European Molecular Biology Laboratory和DNA Data Bank of Japan 3个数据库比对,得到分子鉴定结果.结果 形态学鉴定为黄曲霉的56株曲霉中,经ITS序列分析鉴定为黄曲霉55株,寄生曲霉1株,β-微管蛋白基因序列分析结果与ITS序列分析相同;形态学鉴定为烟曲霉的37株曲霉中,ITS序列分析鉴定为37株烟曲霉复合种,β-微管蛋白基因序列分析鉴定为烟曲霉35株和仑图卢斯曲霉2株;形态学鉴定为杂色曲霉的21株曲霉中,ITS序列分析鉴定为杂色曲霉16株和未鉴定到种的曲霉5株,β-微管蛋白基因序列分析鉴定为杂色曲霉16株和聚多曲霉5株;形态学鉴定为构巢曲霉的10株曲霉中,ITS序列分析和β-微管蛋白基因序列分析均鉴定为构巢曲霉.结论 β-微管蛋白基因序列分析曲霉的分辨率较ITS序列分析高,可以将曲霉准确鉴定到种,ITS序列可以分析到曲霉复合种.

Abstract：

Objective To study the clinical application of the ITS and β-tubulin gene regions in identification of Aspergillus spp. Methods One hundred and twenty-four Aspergillus strains that isolated from fungal rhino-sinusitis specimens were collected in Beijing Tongren Hospital, Capital Medical University from July 2007 to January 2010. They were identified by morphological and molecular methods. The first one included traditional culture, slide culture, and microscopic examination after lactophenol cotton blue stain and KOH digestion. The second one was amplifying and sequencing the part of ITS and β-tubulin gene and aligned all the sequences in the GenBank, European Molecular Biology Laboratory nucleotide sequence database, and DNA Data Bank of Japan. Results Of the 56 Aspergillus flavus identified by morphological features, fifty-five isolates were identified as Aspergillus flavus and 1 isolates was Aspergillus parasiticus by the ITS and β-tubulin gene region sequence analysis. In the 37 Aspergillus fumigatus identified by morphological method, and all the 37 isolates were identified as species complex of Aspergillus fumigatus by the ITS region sequence analysis, but through the sequence analysis of β-tubulin gene region, thirty-five isolates were identified as Aspergillus. fumigatus and 2 were Aspergillus lentulus. Twenty-one isolates were identified as Aspergillus versicolor by morphological method, but 16 of them were identified as Aspergillus. versicolor and 5 can not be identified to species level by the ITS region sequence. And by comparative-sequence analysis of β-tubulin gene region, the 5 isolates were identified as Aspergillus sydowii,the other 16 isolates were Aspergillus. versilcolor. Ten isolates were identified as Aspergillus nidulans by morphological features, the ITS and β-tubulin gene region sequence analysis. Conclusions β-tubulin gene sequencing is more suitable for identifying Aspergillus, and could identify Aspergillus spp. to species level Sequences of ITS region could only identify Aspergillus spp. to species complex.     

变性高效液相色谱对CTX-M型超广谱β内酰胺酶基因分型研究

Objective To investigate the genotype distribution of CTX-M-type extended-spectrum β-1actamase(ESBLs) by denaturing high-performance liquid chromatography(DHPLC) in Hunan Province and the accuracy of DHPLC assay. Methods The blaCTX-M genes of standard strains and clinical ESBLs-producing Enterobacteriaceae were amplified by multiplex PCR followed by DHPLC and genotype determination. 25 isolates randomly selected were sequenced to assess the accuracy of DHPLC method. Results Among 142 ESBLs-producing isolates, 109 isolates carried blaCTX-M gene (76. 8% ). Four different CTX-M genotypes were detected by DHPLC, including CTX-M-3 (33 isolates), CTX-M-15 (19 isolates), CTX-M-14 (52 isolates) and CTX-M-9 (5 isolates). The DHPLC typing of 25 isolates suggested that 24 isolates were verified uniformly by the sequencing, but one CTX-M-15 isolate typed by DHPLC was shown to be CTX-M-82 by sequencing. Conclusion DHPLC is a powerful tool for genotyping of the resistance gene and is worth being applied in the clinical and scientific research with accurate, rapid and economic advantages.     

变性高效液相色谱对CTX-M型超广谱β内酰胺酶基因分型研究

Objective To investigate the genotype distribution of CTX-M-type extended-spectrum β-1actamase(ESBLs) by denaturing high-performance liquid chromatography(DHPLC) in Hunan Province and the accuracy of DHPLC assay. Methods The blaCTX-M genes of standard strains and clinical ESBLs-producing Enterobacteriaceae were amplified by multiplex PCR followed by DHPLC and genotype determination. 25 isolates randomly selected were sequenced to assess the accuracy of DHPLC method. Results Among 142 ESBLs-producing isolates, 109 isolates carried blaCTX-M gene (76. 8% ). Four different CTX-M genotypes were detected by DHPLC, including CTX-M-3 (33 isolates), CTX-M-15 (19 isolates), CTX-M-14 (52 isolates) and CTX-M-9 (5 isolates). The DHPLC typing of 25 isolates suggested that 24 isolates were verified uniformly by the sequencing, but one CTX-M-15 isolate typed by DHPLC was shown to be CTX-M-82 by sequencing. Conclusion DHPLC is a powerful tool for genotyping of the resistance gene and is worth being applied in the clinical and scientific research with accurate, rapid and economic advantages.     

变性高效液相色谱对CTX-M型超广谱β内酰胺酶基因分型研究

Objective To investigate the genotype distribution of CTX-M-type extended-spectrum β-1actamase(ESBLs) by denaturing high-performance liquid chromatography(DHPLC) in Hunan Province and the accuracy of DHPLC assay. Methods The blaCTX-M genes of standard strains and clinical ESBLs-producing Enterobacteriaceae were amplified by multiplex PCR followed by DHPLC and genotype determination. 25 isolates randomly selected were sequenced to assess the accuracy of DHPLC method. Results Among 142 ESBLs-producing isolates, 109 isolates carried blaCTX-M gene (76. 8% ). Four different CTX-M genotypes were detected by DHPLC, including CTX-M-3 (33 isolates), CTX-M-15 (19 isolates), CTX-M-14 (52 isolates) and CTX-M-9 (5 isolates). The DHPLC typing of 25 isolates suggested that 24 isolates were verified uniformly by the sequencing, but one CTX-M-15 isolate typed by DHPLC was shown to be CTX-M-82 by sequencing. Conclusion DHPLC is a powerful tool for genotyping of the resistance gene and is worth being applied in the clinical and scientific research with accurate, rapid and economic advantages.     

变性高效液相色谱对CTX-M型超广谱β内酰胺酶基因分型研究

Objective To investigate the genotype distribution of CTX-M-type extended-spectrum β-1actamase(ESBLs) by denaturing high-performance liquid chromatography(DHPLC) in Hunan Province and the accuracy of DHPLC assay. Methods The blaCTX-M genes of standard strains and clinical ESBLs-producing Enterobacteriaceae were amplified by multiplex PCR followed by DHPLC and genotype determination. 25 isolates randomly selected were sequenced to assess the accuracy of DHPLC method. Results Among 142 ESBLs-producing isolates, 109 isolates carried blaCTX-M gene (76. 8% ). Four different CTX-M genotypes were detected by DHPLC, including CTX-M-3 (33 isolates), CTX-M-15 (19 isolates), CTX-M-14 (52 isolates) and CTX-M-9 (5 isolates). The DHPLC typing of 25 isolates suggested that 24 isolates were verified uniformly by the sequencing, but one CTX-M-15 isolate typed by DHPLC was shown to be CTX-M-82 by sequencing. Conclusion DHPLC is a powerful tool for genotyping of the resistance gene and is worth being applied in the clinical and scientific research with accurate, rapid and economic advantages.     

变性高效液相色谱对CTX-M型超广谱β内酰胺酶基因分型研究

Objective To investigate the genotype distribution of CTX-M-type extended-spectrum β-1actamase(ESBLs) by denaturing high-performance liquid chromatography(DHPLC) in Hunan Province and the accuracy of DHPLC assay. Methods The blaCTX-M genes of standard strains and clinical ESBLs-producing Enterobacteriaceae were amplified by multiplex PCR followed by DHPLC and genotype determination. 25 isolates randomly selected were sequenced to assess the accuracy of DHPLC method. Results Among 142 ESBLs-producing isolates, 109 isolates carried blaCTX-M gene (76. 8% ). Four different CTX-M genotypes were detected by DHPLC, including CTX-M-3 (33 isolates), CTX-M-15 (19 isolates), CTX-M-14 (52 isolates) and CTX-M-9 (5 isolates). The DHPLC typing of 25 isolates suggested that 24 isolates were verified uniformly by the sequencing, but one CTX-M-15 isolate typed by DHPLC was shown to be CTX-M-82 by sequencing. Conclusion DHPLC is a powerful tool for genotyping of the resistance gene and is worth being applied in the clinical and scientific research with accurate, rapid and economic advantages.     

变性高效液相色谱对CTX-M型超广谱β内酰胺酶基因分型研究

Objective To investigate the genotype distribution of CTX-M-type extended-spectrum β-1actamase(ESBLs) by denaturing high-performance liquid chromatography(DHPLC) in Hunan Province and the accuracy of DHPLC assay. Methods The blaCTX-M genes of standard strains and clinical ESBLs-producing Enterobacteriaceae were amplified by multiplex PCR followed by DHPLC and genotype determination. 25 isolates randomly selected were sequenced to assess the accuracy of DHPLC method. Results Among 142 ESBLs-producing isolates, 109 isolates carried blaCTX-M gene (76. 8% ). Four different CTX-M genotypes were detected by DHPLC, including CTX-M-3 (33 isolates), CTX-M-15 (19 isolates), CTX-M-14 (52 isolates) and CTX-M-9 (5 isolates). The DHPLC typing of 25 isolates suggested that 24 isolates were verified uniformly by the sequencing, but one CTX-M-15 isolate typed by DHPLC was shown to be CTX-M-82 by sequencing. Conclusion DHPLC is a powerful tool for genotyping of the resistance gene and is worth being applied in the clinical and scientific research with accurate, rapid and economic advantages.     

变性高效液相色谱对CTX-M型超广谱β内酰胺酶基因分型研究

Objective To investigate the genotype distribution of CTX-M-type extended-spectrum β-1actamase(ESBLs) by denaturing high-performance liquid chromatography(DHPLC) in Hunan Province and the accuracy of DHPLC assay. Methods The blaCTX-M genes of standard strains and clinical ESBLs-producing Enterobacteriaceae were amplified by multiplex PCR followed by DHPLC and genotype determination. 25 isolates randomly selected were sequenced to assess the accuracy of DHPLC method. Results Among 142 ESBLs-producing isolates, 109 isolates carried blaCTX-M gene (76. 8% ). Four different CTX-M genotypes were detected by DHPLC, including CTX-M-3 (33 isolates), CTX-M-15 (19 isolates), CTX-M-14 (52 isolates) and CTX-M-9 (5 isolates). The DHPLC typing of 25 isolates suggested that 24 isolates were verified uniformly by the sequencing, but one CTX-M-15 isolate typed by DHPLC was shown to be CTX-M-82 by sequencing. Conclusion DHPLC is a powerful tool for genotyping of the resistance gene and is worth being applied in the clinical and scientific research with accurate, rapid and economic advantages.     

变性高效液相色谱对CTX-M型超广谱β内酰胺酶基因分型研究

Objective To investigate the genotype distribution of CTX-M-type extended-spectrum β-1actamase(ESBLs) by denaturing high-performance liquid chromatography(DHPLC) in Hunan Province and the accuracy of DHPLC assay. Methods The blaCTX-M genes of standard strains and clinical ESBLs-producing Enterobacteriaceae were amplified by multiplex PCR followed by DHPLC and genotype determination. 25 isolates randomly selected were sequenced to assess the accuracy of DHPLC method. Results Among 142 ESBLs-producing isolates, 109 isolates carried blaCTX-M gene (76. 8% ). Four different CTX-M genotypes were detected by DHPLC, including CTX-M-3 (33 isolates), CTX-M-15 (19 isolates), CTX-M-14 (52 isolates) and CTX-M-9 (5 isolates). The DHPLC typing of 25 isolates suggested that 24 isolates were verified uniformly by the sequencing, but one CTX-M-15 isolate typed by DHPLC was shown to be CTX-M-82 by sequencing. Conclusion DHPLC is a powerful tool for genotyping of the resistance gene and is worth being applied in the clinical and scientific research with accurate, rapid and economic advantages.     

变性高效液相色谱对CTX-M型超广谱β内酰胺酶基因分型研究

Objective To investigate the genotype distribution of CTX-M-type extended-spectrum β-1actamase(ESBLs) by denaturing high-performance liquid chromatography(DHPLC) in Hunan Province and the accuracy of DHPLC assay. Methods The blaCTX-M genes of standard strains and clinical ESBLs-producing Enterobacteriaceae were amplified by multiplex PCR followed by DHPLC and genotype determination. 25 isolates randomly selected were sequenced to assess the accuracy of DHPLC method. Results Among 142 ESBLs-producing isolates, 109 isolates carried blaCTX-M gene (76. 8% ). Four different CTX-M genotypes were detected by DHPLC, including CTX-M-3 (33 isolates), CTX-M-15 (19 isolates), CTX-M-14 (52 isolates) and CTX-M-9 (5 isolates). The DHPLC typing of 25 isolates suggested that 24 isolates were verified uniformly by the sequencing, but one CTX-M-15 isolate typed by DHPLC was shown to be CTX-M-82 by sequencing. Conclusion DHPLC is a powerful tool for genotyping of the resistance gene and is worth being applied in the clinical and scientific research with accurate, rapid and economic advantages.     

变性高效液相色谱对CTX-M型超广谱β内酰胺酶基因分型研究

Objective To investigate the genotype distribution of CTX-M-type extended-spectrum β-1actamase(ESBLs) by denaturing high-performance liquid chromatography(DHPLC) in Hunan Province and the accuracy of DHPLC assay. Methods The blaCTX-M genes of standard strains and clinical ESBLs-producing Enterobacteriaceae were amplified by multiplex PCR followed by DHPLC and genotype determination. 25 isolates randomly selected were sequenced to assess the accuracy of DHPLC method. Results Among 142 ESBLs-producing isolates, 109 isolates carried blaCTX-M gene (76. 8% ). Four different CTX-M genotypes were detected by DHPLC, including CTX-M-3 (33 isolates), CTX-M-15 (19 isolates), CTX-M-14 (52 isolates) and CTX-M-9 (5 isolates). The DHPLC typing of 25 isolates suggested that 24 isolates were verified uniformly by the sequencing, but one CTX-M-15 isolate typed by DHPLC was shown to be CTX-M-82 by sequencing. Conclusion DHPLC is a powerful tool for genotyping of the resistance gene and is worth being applied in the clinical and scientific research with accurate, rapid and economic advantages.     

X-连锁迟发性脊髓骨骺发育不良家系的基因诊断

ObjectiveTo investigate the molecular pathogenesis of a pedigree of X-linked spondyloepiphyseal dysplasia atarda (SEDL) and to establish methods of gene diagnosis. Methods Clinical diagnosis was made based on height measurement, radiological examination and pedigree analysis. Peripheral blood samples of relevant family members were collected. After genomic DNA extraction, single strand conformation polymorphism (SSCP) followed with DNA sequencing was used to detect SEDL gene exons 36. Microsatellite marker DXS16 was selected for linkage analysis. Results The abnormal electrophoretic bands were detected in exon 4 of probands by PCR-SSCP. A c. 218C ＞ T mutation in exon 4 of SEDL gene was found in three probands, which resulted in a change in amino acid sequence S37L. The heterozygous exon 4 mutation was identified in three carriers, but not in healthy individuals, and no mutations were detect in exon 3, 5 and 6 of probands. Three unmarried young females (Ⅲ10, Ⅳ6 and Ⅳ7) were found to harbor the mutation by DNA sequencing analysis. ConclusionsA c. 218C ＞ T missense mutation in exon 4 of SEDL gene is the cause of molecular pathogenesis of the pedigree. SSCP and DNA sequencing can be used for prenatal gene diagnosis.     

X-连锁迟发性脊髓骨骺发育不良家系的基因诊断

ObjectiveTo investigate the molecular pathogenesis of a pedigree of X-linked spondyloepiphyseal dysplasia atarda (SEDL) and to establish methods of gene diagnosis. Methods Clinical diagnosis was made based on height measurement, radiological examination and pedigree analysis. Peripheral blood samples of relevant family members were collected. After genomic DNA extraction, single strand conformation polymorphism (SSCP) followed with DNA sequencing was used to detect SEDL gene exons 36. Microsatellite marker DXS16 was selected for linkage analysis. Results The abnormal electrophoretic bands were detected in exon 4 of probands by PCR-SSCP. A c. 218C ＞ T mutation in exon 4 of SEDL gene was found in three probands, which resulted in a change in amino acid sequence S37L. The heterozygous exon 4 mutation was identified in three carriers, but not in healthy individuals, and no mutations were detect in exon 3, 5 and 6 of probands. Three unmarried young females (Ⅲ10, Ⅳ6 and Ⅳ7) were found to harbor the mutation by DNA sequencing analysis. ConclusionsA c. 218C ＞ T missense mutation in exon 4 of SEDL gene is the cause of molecular pathogenesis of the pedigree. SSCP and DNA sequencing can be used for prenatal gene diagnosis.     

多重耐药不动杆菌16S rRNA甲基化酶和同源性研究

Objective To characterize 16S rRNA methylase encoding genes associated with aminoglycoaides resistance, gene cassettes of class Ⅰ integrons of the multidrug-resistant Acinetobctcter spp. The sixty one Acinetobacter isolates were collected at the Second Hospital of Shanxi Medical Uni versity from July, 2007 to May, 2008. Methods Species identification was confirmed by sequence analysis of the blaOXA-51-like gene and 16S-23S rRNA gene space-region. Antimierobial susceptibility tests were performed by agar dilution method. 16S rRNA methylaae encoding genes and gene cassettes associated with integrons were amplified by PCR method. Results Among the sixty one strains, there were fifty five of Acinetobacter baumannii, three genospecies 3TU, one 13TU, one Aeinetobaeter ealcoacetieus, and one Aeinetobaeter haemolytieus. Forty eight isolates showed high-level resistance to three aminoglyeosides, including amikaein, tobramyein and gentamicin. The armA gene was found in 47 isolates and all isolates were negative for rmtA, rmtB, rmtC and rmtD genes. The Intl gene was found in 27 isolates. The gene cassettes contained arr-3, accA4,ctacCI ,catB8, aadA1 or dfrA12 genes. According to the PFGE DNA patterns, 5 distinct clones of armA-pasitive strains were identified. Clone A and Clone B were the dominant clones, widely distributed among different divisions. Condnsions 16S rRNA methylase encoding gene (armA) distributed widely in muhidrug-resistant Acinetobacter spp. The armA gene is not located in class Ⅰintegron. The class Ⅰ integron carries multiple resistant genes associated with aminoglycosides and chloramphenieol resistance.PFGE analysis suggests that armA-pesitive strains are widely spread in our hospitaL Effective infection control measure should be conducted in order to control the outbreak of resistant bacteria.     

多重耐药不动杆菌16S rRNA甲基化酶和同源性研究

Objective To characterize 16S rRNA methylase encoding genes associated with aminoglycoaides resistance, gene cassettes of class Ⅰ integrons of the multidrug-resistant Acinetobctcter spp. The sixty one Acinetobacter isolates were collected at the Second Hospital of Shanxi Medical Uni versity from July, 2007 to May, 2008. Methods Species identification was confirmed by sequence analysis of the blaOXA-51-like gene and 16S-23S rRNA gene space-region. Antimierobial susceptibility tests were performed by agar dilution method. 16S rRNA methylaae encoding genes and gene cassettes associated with integrons were amplified by PCR method. Results Among the sixty one strains, there were fifty five of Acinetobacter baumannii, three genospecies 3TU, one 13TU, one Aeinetobaeter ealcoacetieus, and one Aeinetobaeter haemolytieus. Forty eight isolates showed high-level resistance to three aminoglyeosides, including amikaein, tobramyein and gentamicin. The armA gene was found in 47 isolates and all isolates were negative for rmtA, rmtB, rmtC and rmtD genes. The Intl gene was found in 27 isolates. The gene cassettes contained arr-3, accA4,ctacCI ,catB8, aadA1 or dfrA12 genes. According to the PFGE DNA patterns, 5 distinct clones of armA-pasitive strains were identified. Clone A and Clone B were the dominant clones, widely distributed among different divisions. Condnsions 16S rRNA methylase encoding gene (armA) distributed widely in muhidrug-resistant Acinetobacter spp. The armA gene is not located in class Ⅰintegron. The class Ⅰ integron carries multiple resistant genes associated with aminoglycosides and chloramphenieol resistance.PFGE analysis suggests that armA-pesitive strains are widely spread in our hospitaL Effective infection control measure should be conducted in order to control the outbreak of resistant bacteria.     

多重耐药不动杆菌16S rRNA甲基化酶和同源性研究

Objective To characterize 16S rRNA methylase encoding genes associated with aminoglycoaides resistance, gene cassettes of class Ⅰ integrons of the multidrug-resistant Acinetobctcter spp. The sixty one Acinetobacter isolates were collected at the Second Hospital of Shanxi Medical Uni versity from July, 2007 to May, 2008. Methods Species identification was confirmed by sequence analysis of the blaOXA-51-like gene and 16S-23S rRNA gene space-region. Antimierobial susceptibility tests were performed by agar dilution method. 16S rRNA methylaae encoding genes and gene cassettes associated with integrons were amplified by PCR method. Results Among the sixty one strains, there were fifty five of Acinetobacter baumannii, three genospecies 3TU, one 13TU, one Aeinetobaeter ealcoacetieus, and one Aeinetobaeter haemolytieus. Forty eight isolates showed high-level resistance to three aminoglyeosides, including amikaein, tobramyein and gentamicin. The armA gene was found in 47 isolates and all isolates were negative for rmtA, rmtB, rmtC and rmtD genes. The Intl gene was found in 27 isolates. The gene cassettes contained arr-3, accA4,ctacCI ,catB8, aadA1 or dfrA12 genes. According to the PFGE DNA patterns, 5 distinct clones of armA-pasitive strains were identified. Clone A and Clone B were the dominant clones, widely distributed among different divisions. Condnsions 16S rRNA methylase encoding gene (armA) distributed widely in muhidrug-resistant Acinetobacter spp. The armA gene is not located in class Ⅰintegron. The class Ⅰ integron carries multiple resistant genes associated with aminoglycosides and chloramphenieol resistance.PFGE analysis suggests that armA-pesitive strains are widely spread in our hospitaL Effective infection control measure should be conducted in order to control the outbreak of resistant bacteria.     

多重耐药不动杆菌16S rRNA甲基化酶和同源性研究

Objective To characterize 16S rRNA methylase encoding genes associated with aminoglycoaides resistance, gene cassettes of class Ⅰ integrons of the multidrug-resistant Acinetobctcter spp. The sixty one Acinetobacter isolates were collected at the Second Hospital of Shanxi Medical Uni versity from July, 2007 to May, 2008. Methods Species identification was confirmed by sequence analysis of the blaOXA-51-like gene and 16S-23S rRNA gene space-region. Antimierobial susceptibility tests were performed by agar dilution method. 16S rRNA methylaae encoding genes and gene cassettes associated with integrons were amplified by PCR method. Results Among the sixty one strains, there were fifty five of Acinetobacter baumannii, three genospecies 3TU, one 13TU, one Aeinetobaeter ealcoacetieus, and one Aeinetobaeter haemolytieus. Forty eight isolates showed high-level resistance to three aminoglyeosides, including amikaein, tobramyein and gentamicin. The armA gene was found in 47 isolates and all isolates were negative for rmtA, rmtB, rmtC and rmtD genes. The Intl gene was found in 27 isolates. The gene cassettes contained arr-3, accA4,ctacCI ,catB8, aadA1 or dfrA12 genes. According to the PFGE DNA patterns, 5 distinct clones of armA-pasitive strains were identified. Clone A and Clone B were the dominant clones, widely distributed among different divisions. Condnsions 16S rRNA methylase encoding gene (armA) distributed widely in muhidrug-resistant Acinetobacter spp. The armA gene is not located in class Ⅰintegron. The class Ⅰ integron carries multiple resistant genes associated with aminoglycosides and chloramphenieol resistance.PFGE analysis suggests that armA-pesitive strains are widely spread in our hospitaL Effective infection control measure should be conducted in order to control the outbreak of resistant bacteria.     

多重耐药不动杆菌16S rRNA甲基化酶和同源性研究

Objective To characterize 16S rRNA methylase encoding genes associated with aminoglycoaides resistance, gene cassettes of class Ⅰ integrons of the multidrug-resistant Acinetobctcter spp. The sixty one Acinetobacter isolates were collected at the Second Hospital of Shanxi Medical Uni versity from July, 2007 to May, 2008. Methods Species identification was confirmed by sequence analysis of the blaOXA-51-like gene and 16S-23S rRNA gene space-region. Antimierobial susceptibility tests were performed by agar dilution method. 16S rRNA methylaae encoding genes and gene cassettes associated with integrons were amplified by PCR method. Results Among the sixty one strains, there were fifty five of Acinetobacter baumannii, three genospecies 3TU, one 13TU, one Aeinetobaeter ealcoacetieus, and one Aeinetobaeter haemolytieus. Forty eight isolates showed high-level resistance to three aminoglyeosides, including amikaein, tobramyein and gentamicin. The armA gene was found in 47 isolates and all isolates were negative for rmtA, rmtB, rmtC and rmtD genes. The Intl gene was found in 27 isolates. The gene cassettes contained arr-3, accA4,ctacCI ,catB8, aadA1 or dfrA12 genes. According to the PFGE DNA patterns, 5 distinct clones of armA-pasitive strains were identified. Clone A and Clone B were the dominant clones, widely distributed among different divisions. Condnsions 16S rRNA methylase encoding gene (armA) distributed widely in muhidrug-resistant Acinetobacter spp. The armA gene is not located in class Ⅰintegron. The class Ⅰ integron carries multiple resistant genes associated with aminoglycosides and chloramphenieol resistance.PFGE analysis suggests that armA-pesitive strains are widely spread in our hospitaL Effective infection control measure should be conducted in order to control the outbreak of resistant bacteria.     

多重耐药不动杆菌16S rRNA甲基化酶和同源性研究

Objective To characterize 16S rRNA methylase encoding genes associated with aminoglycoaides resistance, gene cassettes of class Ⅰ integrons of the multidrug-resistant Acinetobctcter spp. The sixty one Acinetobacter isolates were collected at the Second Hospital of Shanxi Medical Uni versity from July, 2007 to May, 2008. Methods Species identification was confirmed by sequence analysis of the blaOXA-51-like gene and 16S-23S rRNA gene space-region. Antimierobial susceptibility tests were performed by agar dilution method. 16S rRNA methylaae encoding genes and gene cassettes associated with integrons were amplified by PCR method. Results Among the sixty one strains, there were fifty five of Acinetobacter baumannii, three genospecies 3TU, one 13TU, one Aeinetobaeter ealcoacetieus, and one Aeinetobaeter haemolytieus. Forty eight isolates showed high-level resistance to three aminoglyeosides, including amikaein, tobramyein and gentamicin. The armA gene was found in 47 isolates and all isolates were negative for rmtA, rmtB, rmtC and rmtD genes. The Intl gene was found in 27 isolates. The gene cassettes contained arr-3, accA4,ctacCI ,catB8, aadA1 or dfrA12 genes. According to the PFGE DNA patterns, 5 distinct clones of armA-pasitive strains were identified. Clone A and Clone B were the dominant clones, widely distributed among different divisions. Condnsions 16S rRNA methylase encoding gene (armA) distributed widely in muhidrug-resistant Acinetobacter spp. The armA gene is not located in class Ⅰintegron. The class Ⅰ integron carries multiple resistant genes associated with aminoglycosides and chloramphenieol resistance.PFGE analysis suggests that armA-pesitive strains are widely spread in our hospitaL Effective infection control measure should be conducted in order to control the outbreak of resistant bacteria.