Antibacterial activity of soil-bound antibiotics
Antibacterial activity of soil-bound antibiotics
复制标题
DOI：
10.2134/jeq2005.0017
复制
发表时间：
2005-11-01
影响因子：
2.4
通讯作者：
Gupta, SC
中科院分区：
文献类型：
--
作者：
Chander, Y;Kumar, K;Gupta, SC
有人担心，土地施用的粪肥中的抗生素残留可能会促进环境中抗生素耐药性细菌的出现。这项研究的目的是确定土壤结合的抗生素是否仍然对细菌有效。该程序涉及在两种不同质地的土壤上吸附不同量的四环素或泰乐菌素（韦伯斯特粘壤土[细壤土，混合，超活性，中质典型内含水层]和Hubbard壤土砂[桑迪，混合，寒冷Entic Hapuldolls]），用三种不同的细菌培养物孵育这些土壤（沙门氏菌属的抗生素抗性菌株[沙门氏菌（R）]、沙门氏菌属的抗生素敏感菌株[沙门氏菌（S）]和大肠杆菌ATCC 25922），然后计数相对于对照的菌落形成单位数。在静态和动态条件下进行孵育。土壤吸附的抗生素被发现保留其抗菌特性，因为这两种抗生素抑制所有三种细菌的生长。在所有其他因素的平均值，土壤吸附的抗微生物活性是哈伯德壤土砂高于韦伯斯特粘壤土，最有可能是由于更高的亲和力（较高的粘土含量）的韦伯斯特土壤的抗生素。同样，四环素组的细菌生长下降幅度大于泰乐菌素组，这可能是由于土壤吸附的四环素量更大，也可能是由于大多数细菌对四环素的最低抑菌浓度低于泰乐菌素。四环素的抗微生物效果也更大的动态比静态生长条件下，可能是因为在动态生长条件下搅拌有助于增加四环素解吸和/或增加土壤吸附四环素和细菌之间的接触。我们的结论是，即使抗生素被粘土颗粒紧密吸附，它们仍然具有生物活性，并可能影响陆地环境中抗生素耐药菌的选择。
There is some concern that antibiotic residues in land-applied manure may promote the emergence of antibiotic resistant bacteria in the environment. The goal of this study was to determine whether or not soil bound antibiotics are still active against bacteria. The procedure involved sorbing various amounts of tetracycline or tylosin on two different textured soils (Webster clay loam [fine-loamy, mixed, superactive, mesic Typic Endoaquolls] and Hubbard loamy sand [sandy, mixed, frigid Entic Hapludolls]), incubating these soils with three different bacterial cultures (an antibiotic resistant strain of Salmonella sp. [Salmonella(R)], an antibiotic sensitive strain of Salmonella sp. [Salmonella(S)], and Escherichia coli ATCC 25922), and then enumerating the number of colony forming units relative to the control. Incubation was done under both static and dynamic conditions. Soil-adsorbed antibiotics were found to retain their antimicrobial properties since both antibiotics inhibited the growth of all three bacterial species. Averaged over all other factors, soil adsorbed antimicrobial activity was higher for Hubbard loamy sand than Webster clay loam, most likely due to higher affinity (higher clay content) of the Webster soil for antibiotics. Similarly, there was a greater decline in bacterial growth with tetracycline than tylsoin, likely due to greater amounts of soil-adsorbed tetracycline and also due to lower minimum inhibitory concentration of most bacteria for tetracycline than tylosin. The antimicrobial effect of tetracycline was also greater under dynamic than static growth conditions, possibly because agitation under dynamic growth conditions helped increase tetracycline desorption and/or increase contact between soil adsorbed tetracycline and bacteria. We conclude that even though antibiotics are tightly adsorbed by clay particles, they are still biologically active and may influence the selection of antibiotic resistant bacteria in the terrestrial environment.