Among various species of marine bacteria, those belonging to the genus Halomonas have several promising applications and have been studied well. However, there was not much information on antibiotic resistance of Halomonas species. As an effort to find antibiotic resistance of Halomonas socia CKY01, which showed production of various hydrolases and growth promotion by osmolytes in previous study, we found that it exhibited resistance to multiple antibiotics, including kanamycin, ampicillin, oxacillin, carbenicillin, gentamicin, apramycin, tetracycline, and spectinomycin. However, the H. socia CKY01 resistance pattern to kanamycin, gentamicin, apramycin, tetracycline, and spectinomycin was different in the presence of 10% NaCl and 1% NaCl in the culture medium. To determine the mechanism underlying NaCl concentration-dependent antibiotic resistance, we compared four aminoglycoside resistance genes under different salt conditions, and by performing time dependent reverse transcription PCR. We found that aminoglycoside phosphotransferase (aph2) showed increased expression under the 10% than 1% NaCl conditions. When these genes were overexpressed in an Escherichia coli strain, pETDuet-1::aph2 showed a smaller inhibition zone in the presence of kanamycin, gentamicin, and apramycin than the respective control suggesting aph2 was involved in aminoglycoside resistance. Our results showed a more direct link between NaCl and aminoglycoside resistance exhibited by the H. socia CKY01 strain.

中文翻译：

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Halomonas socia CKY01 的 NaCl 浓度依赖性氨基糖苷类抗性及相关基因的鉴定。

在各种海洋细菌中，属于盐单胞菌属的细菌具有多种有前途的应用，并且已得到深入研究。然而，关于盐单胞菌属物种的抗生素抗性的信息并不多。为了发现Halomonas socia CKY01 的抗生素耐药性，在先前的研究中，它显示出各种水解酶的产生和渗透剂的促进生长，我们发现它对多种抗生素表现出耐药性，包括卡那霉素、氨苄青霉素、苯唑西林、羧苄青霉素、庆大霉素、安普霉素、四环素和大观霉素。然而，H. socia在培养基中存在 10% NaCl 和 1% NaCl 时，CKY01 对卡那霉素、庆大霉素、安普霉素、四环素和大观霉素的耐药模式是不同的。为了确定 NaCl 浓度依赖性抗生素抗性的潜在机制，我们比较了不同盐条件下的四种氨基糖苷类抗性基因，并通过进行时间依赖性逆转录 PCR。我们发现氨基糖苷磷酸转移酶 ( aph2 ) 在 10% 比 1% NaCl 条件下表现出增加的表达。当这些基因在大肠杆菌菌株中过表达时，pETDuet-1:: aph2在存在卡那霉素、庆大霉素和安普霉素的情况下显示出比各自的对照更小的抑制区，表明aph2参与氨基糖苷类耐药。我们的结果显示了H. socia CKY01 菌株表现出的 NaCl 和氨基糖苷类抗性之间更直接的联系。