每年,，因?yàn)楦腥拘缘募膊】梢詫?dǎo)致1300萬(wàn)人死亡,，而且每年死亡的人數(shù)都在增加之中，這都?xì)w因于致病菌中的抗性基因,，近日,，一項(xiàng)刊登在國(guó)際雜志Antimicrobial Agents and Chemotherapy的一篇研究指出，在農(nóng)田土壤中也存在著大量的抗性菌株,，土壤中包含了眾多不同的耐藥細(xì)菌,，而且這些細(xì)菌的耐藥性比堆肥和森林土壤中細(xì)菌的耐藥性都強(qiáng)，蔬菜菜園的土壤中當(dāng)然也含有大量的耐藥菌株,，而且對(duì)于目前的三大抗生素都有著高度的耐藥性,。
來(lái)自波蘭華沙大學(xué)的研究者M(jìn)agdalena Popowska表示，我們的研究中發(fā)現(xiàn)了世界范圍內(nèi)的農(nóng)田土壤中存在著高度耐藥水平的耐藥菌株,?？股匾约凹?xì)菌的耐藥基因的出現(xiàn)都是長(zhǎng)期微生物在競(jìng)爭(zhēng)地盤(pán)的斗爭(zhēng)中慢慢進(jìn)化來(lái)的，從土壤中分離出的至少50%的放線菌都有能力分泌抗生素,，這種被分泌的抗生素殘留長(zhǎng)期存在于土壤中,，但是日常生活中，我們?cè)陲暳现刑砑涌股貛椭倚笊L(zhǎng),，但是不能被吸收的抗生素就會(huì)混合在糞肥中,，這樣一來(lái)，用糞肥灌溉農(nóng)田以及菜園,，時(shí)間一長(zhǎng),，慢慢就會(huì)增加土壤中細(xì)菌的耐藥性。
Popowska表示,，多重耐藥致病菌以及機(jī)會(huì)致病菌耐藥性的普遍存在不僅僅會(huì)感染人和動(dòng)物,，而且這種耐藥性也會(huì)隨著遺傳因子進(jìn)行轉(zhuǎn)移,，比如通過(guò)質(zhì)粒以及轉(zhuǎn)座子介導(dǎo)的遺傳轉(zhuǎn)移，慢慢就會(huì)將耐藥性轉(zhuǎn)移到細(xì)菌相同的種中,，也會(huì)轉(zhuǎn)移到不同種的細(xì)菌中,。她還補(bǔ)充道，研究結(jié)果還提示,，在養(yǎng)魚(yú)以及工業(yè)上,，抗生素的合理利用對(duì)環(huán)境中耐藥細(xì)菌的控制尤為重要，而且我們相信我們可以進(jìn)行最優(yōu)化的選擇去和耐藥細(xì)菌斗爭(zhēng)或者用更好的化學(xué)藥物來(lái)抵御耐藥細(xì)菌的感染或者散布,。
研究者最后還表示,，對(duì)于危險(xiǎn)嚴(yán)格的細(xì)菌感染，抗生素的使用必須尤為嚴(yán)格,，而且監(jiān)管力度也必須嚴(yán)格,，但是目前看來(lái)，這些并沒(méi)有被重視起來(lái),。
（生物谷：T.Shen編譯）
doi:10.1128/AAC.05766-11
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PMID:
Influence of Soil Use on Prevalence of Tetracycline, Streptomycin, and Erythromycin Resistance and Associated Resistance Genes
Magdalena Popowskaa, Marzenna Rzeczyckaa, Antoni Miernika, Agata Krawczyk-Balskaa, Fiona Walshb and Brion Duffyb
This study examined differences in antibiotic-resistant soil bacteria and the presence and quantity of resistance genes in soils with a range of management histories. We analyzed four soils from agricultural systems that were amended with manure from animals treated with erythromycin and exposed to streptomycin and/or oxytetracycline, as well as non-manure-amended compost and forest soil. Low concentrations of certain antibiotic resistance genes were detected using multiplex quantitative real-time PCR (qPCR), with tet(B), aad(A), and str(A) each present in only one soil and tet(M) and tet(W) detected in all soils. The most frequently detected resistance genes were tet(B), tet(D), tet(O), tet(T), and tet(W) for tetracycline resistance, str(A), str(B), and aac for streptomycin resistance, and erm(C), erm(V), erm(X), msr(A), ole(B), and vga for erythromycin resistance. Transposon genes specific for Tn916, Tn1549, TnB1230, Tn4451, and Tn5397 were detected in soil bacterial isolates. The MIC ranges of isolated bacteria for tetracycline, streptomycin, and erythromycin were 8 to >256 μg/ml, 6 to >1,024 μg/ml, and 0.094 to >256 μg/ml, respectively. Based on 16S rRNA gene similarity, isolated bacteria showed high sequence identity to genera typical of soil communities. Bacteria with the highest MICs were detected in manure-amended soils or soils from agricultural systems with a history of antibiotic use. Non-manure-amended soils yielded larger proportions of antibiotic-resistant bacteria, but these had lower MICs, carried fewer antibiotic resistance genes, and did not display multidrug resistance (MDR).
