Fate of sulfadiazine administered to pigs and its quantitative effect on the dynamics of bacterial resistance genes in manure and manured soil
Fate of sulfadiazine administered to pigs and its quantitative effect on the dynamics of bacterial resistance genes in manure and manured soil
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DOI：
10.1016/j.soilbio.2008.03.014
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发表时间：
2008-07-01
影响因子：
9.7
通讯作者：
Spiteller, Michael
中科院分区：
文献类型：
--
作者：
Heuer, Holger;Focks, Andreas;Spiteller, Michael
将（14）C标记的兽用抗生素磺胺嘧啶（SDZ）给予猪，以跟踪药物及其代谢产物在粪肥和粪肥改良土壤中的命运，并研究药物对抗性基因和细菌群落的动态影响。在超过10天的粪便采样中，发现超过96%的药物作为母体化合物或代谢物N-乙酰基-SDZ和4-羟基-SDZ。粪便贮存期间，由于代谢产物N-乙酰基-SDZ的脱乙酰化，SDZ的浓度增加了42%，而次要代谢产物4-羟基-SDZ保持不变。在土壤中的化合物的可提取量呈指数下降到小于1毫克公斤（-1）后11天内粪肥修正。通过qPCR相对于来自粪肥和粪肥改良土壤的总DNA中的16 S rRNA基因来确定SDZ抗性基因sul 1和sul 2的丰度。在粪肥中，两种基因的拷贝数在储存的前60天内呈指数增加，表明抗性种群的优先生长。然而，sul 1和sul 2的丰度在175天后下降到每16 S rRNA基因10（-5）拷贝以下。使用粪肥，大量的sul 1和sul 2被引入土壤中，在24天内减少了10倍以上。此后，sul 1稳定地保持在土壤中，而sul 2进一步下降之间的第60天和第165天。建立了一个数学模型，该模型可以很好地解释sul基因丰度的时间过程，通过考虑sul基因的成本，水平基因转移，以及在SDZ存在下抗性群体的选择。模型显示，SDZ对sul 2的选择性影响，即使在低浓度下至0.15毫克公斤（-1）土壤。粪肥和粪肥改良土壤的细菌群落特征是不同的，这表明粪肥引入的细菌不会在土壤中变得突出。粪便中的细菌群落组成在储存过程中不断变化，但主要是在前10天。土壤细菌群落的配置文件显示，只有一个短暂的扰动粪肥含有SDZ。(C)2008爱思唯尔有限公司版权所有。
The veterinary antibiotic sulfadiazine (SDZ), labelled by (14)C, was administered to pigs to follow the fate of the drug and its metabolites in manure and manure-amended soil, and to investigate the dynamics of drug effects on resistance genes and bacterial communities. In the manure sampled over 10 days, more than 96% of the drug was found as parent compound or metabolites N-acetyl-SDZ and 4-hydroxy-SDZ. While the manure was stored the concentration of SDZ increased by 42% due to deacetylation of the metabolite N-acetyl-SDZ, whereas the minor metabolite 4-hydroxy-SDZ kept constant. In the soil the extractable amounts of the compounds decreased exponentially to less than 1 mg kg(-1) within 11 days after manure amendment. The abundances of SDZ resistance genes sul1 and sul2 were determined by qPCR relative to 16S rRNA genes in total DNA from manure and manure-amended soil. in manure both genes increased exponentially in copy number during the first 60 days of storage, suggesting preferential growth of resistant populations. However, the abundance of sul1 and sul2 decreased below 10(-5) copies per 16S rRNA gene after 175 days. With manure high amounts of sul1 and sul2 were introduced into the soil which were reduced by more than 10 times within 24 days. Thereafter, sul1 was stably maintained in soil, while sul2 further decreased between day 60 and day 165. A mathematical model was developed that could well explain the time course of sul gene abundance by considering the cost of sul genes, horizontal gene transfer, and selection of the resistant populations in the presence of SDZ. Modelling revealed a selective effect of SDZ on sul2 even at low concentrations down to 0.15 mg kg(-1) soil. Bacterial community profiles of manure and manure-amended soil were distinct, indicating that bacteria introduced with manure do not become prominent in soil. The composition of the bacterial community in manure constantly changed during storage, but mainly during the first 10 days. Profiles of soil bacterial communities revealed only a transient perturbation by manure containing SDZ. (C) 2008 Elsevier Ltd. All rights reserved.