Biochemical and molecular characterization of tetracycline-resistant Aeromonas veronii isolates from catfish
Biochemical and molecular characterization of tetracycline-resistant Aeromonas veronii isolates from catfish
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DOI：
10.1128/aem.00271-06
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发表时间：
2006-10-01
影响因子：
4.4
通讯作者：
Steele, Roger
中科院分区：
文献类型：
--
作者：
Nawaz, Mohamed;Sung, Kidon;Steele, Roger
从养殖鲶鱼中分离出81株耐四环素气单胞菌。形态学和生化特征表明，81株气单胞菌中嗜水气单胞菌23株，trota气单胞菌7株，caviae气单胞菌6株，veronii气单胞菌42株，jandaei气单胞菌3株。结果显示，81株鲶鱼耐四环素气单胞菌的1.4 kb 16S rRNA基因的AluI和MboI限制性限制性片段长度多态性（RFLP）与veronii A. ATCC 35626的RFLP带型一致，表明81株分离株均为veronii A.菌株。多重PCR法成功地从所有81株菌株的基因组DNA中扩增出5个四环素耐药基因（tetA to E）。结果表明，WE基因为优势基因，出现在73/81（90.0%）的气单胞菌中。从81株分离株中分离到33株质粒（2.0 ~ 20kb）。SpeI脉冲场凝胶电泳的树突图分析鉴定出15种不同的宏观限制性结构。我们的研究结果表明，16S rRNA在气单胞菌的鉴定和作为tet基因储存库的鲶鱼的流行中有必要使用。
Eighty-one tetracycline-resistant Aeromonas sp. strains were isolated from farm-raised catfish. Morphological and biochemical characteristics indicated that 23 of the 81 aeromonads were Aeromonas hydrophila, 7 isolates were Aeromonas trota, 6 isolates were Aeromonas caviae, 42 isolates were Aeromonas veronii, and 3 isolates were Aeromonas jandaei. However, the AluI and MboI restriction fragment length polymorphism (RFLP) patterns of the PCR-amplified 1.4-kb 16S rRNA gene from all 81 tetracycline-resistant aeromonads from catfish were identical to the RFLP banding patterns of A. veronii ATCC 35626, indicating that all 81 isolates were strains of A. veronii. A multiplex PCR assay successfully amplified the 5 tetracycline-resistant genes (tetA to E) from the genomic DNA of all 81 isolates. The assay determined that WE was the dominant gene occurring in 73/81 (90.0%) of the aeromonads. Plasmids (2.0 to 20 kb) were isolated from 33 of the 81 isolates. Dendrogram analysis of the SpeI pulsed-field gel electrophoresis identified 15 distinct macrorestriction patterns among the isolates. Our results indicate the need for use of 16S rRNA in the identification of Aeromonas spp. and the prevalence of catfish as a reservoir of tet genes.