Heepngoen Pimpak, Sajjaphan Kannika, Ferguson John A, Sadowsky Michael J
Department of Soil Science, Kasetsart University, Cha-tuchak, Bangkok 10900, Thailand.
J Microbiol Biotechnol. 2008 Feb;18(2):199-206.
Four hundred and thirteen oxytetracycline-resistant bacteria were recovered from six freshwater giant prawn farms with a history of oxytetracycline use. Most oxytetracyclineresistant isolates were Gram-negative bacteria. Six groups of oxytetracycline-resistant bacteria were classified using cluster analysis based on a comparison of levels of oxytetracycline resistance. Complex fingerprint patterns were obtained for 71 isolates studied. In general, the band patterns of isolates from different ponds were very similar, and the data indicated that the isolates were closely related. The exploration for crossresistance found that most of the 71 oxytetracycline-resistant isolates were also resistant to tetracycline and chlortetracycline, but had a relatively low resistance to doxycycline. Many isolates showed higher chlortetracycline resistance than oxytetracycline resistance. Additionally, the oxytetracyclineresistant isolates were examined for the presence of tetracycline resistance (tet) genes. Fifty percent of the isolates carried one of the 14 known tet genes examined. The most common determinants were TetA and TetD. However, TetB, TetC, TetE, TetK, TetL, and TetM were also found with various frequencies.
从六个有使用土霉素历史的淡水对虾养殖场中分离出413株耐土霉素细菌。大多数耐土霉素菌株为革兰氏阴性菌。基于土霉素耐药水平的比较，采用聚类分析将耐土霉素细菌分为六组。对71株研究菌株获得了复杂的指纹图谱。总体而言，来自不同池塘的菌株条带模式非常相似，数据表明这些菌株密切相关。交叉耐药性研究发现，71株耐土霉素菌株中的大多数也对四环素和金霉素耐药，但对强力霉素的耐药性相对较低。许多菌株对金霉素的耐药性高于对土霉素的耐药性。此外，检测了耐土霉素菌株中四环素耐药（tet）基因的存在情况。50%的菌株携带所检测的14种已知tet基因中的一种。最常见的决定因素是TetA和TetD。然而，也以不同频率发现了TetB、TetC、TetE、TetK、TetL和TetM。
