Pages

Tuesday, December 27, 2016

北京 空氣樣本中 有超過100種 抗藥性基因 !!!


瑞典研究:北京塵霾藏超級細菌 更新: 20161225 【記者李孜、凌宇/比利時布魯塞爾報導】近日中國被陰霾覆蓋近1/5國土,近5億人受影響。瑞典哥德堡大學的抗生素耐藥研究中心主任拉森(Joakim Larsson)教授的研究團隊近期發表對北京陰霾的研究,指出陰霾裡的一些基因可以使細菌對抗生素產生極強的抗藥性,包括現今最強大的碳青黴烯類抗生素(Carbapenem拉森教授日前接受本報記者採訪時說,「我們的研究是為了弄清楚哪種環境可能造成細菌的潛在傳播。所以基本上我們分析的是DNA。」「我們發現,在北京的空氣樣本中,有超過100種不同的抗生素抗藥性基因這讓我們有些驚訝。這些基因來自於細菌,而且可以存在於大量不同類型的細菌裡,不同的細菌也可以彼此共享這些基因,所以我們很難說該基因到底是來自哪種細菌。另外,我們看到的只是空氣中細菌的DNA它可能來自於已死的菌,而死菌是沒有危險的。而且我們還不知道這些細菌的存活時間。所以我們沒有說任何關於造成風險的事情。」他們的研究發現,這些基因能使細菌對碳青黴烯類抗生素有抗藥性,碳青黴烯類抗生素是目前最重要的治療感染的抗生素,也是人類目前治療細菌感染的最後一道防線。人類在大約75年前發明了抗生素,然而隨著時間的推移,細菌也對不同類型的這些抗生素產生了抗藥性;《紐約時報》和《時代週刊》都報導了拉森教授的研究結果。

中國媒體或解釋過度 中國的一些報導指稱,在北京陰霾中發現了超級抗藥細菌,該報導曾一度引發恐慌,人們擔心一旦被這種極具抗藥性的細菌感染後,就無法用目前已有的抗生素來醫治。對此,拉森教授表示:「目前還不知道這些能夠使細菌產生抗藥性的基因是來自於陰霾裡的活菌還是死菌,兩種可能性都有。中國的媒體認為我們說的是有關受到感染風險的問題,但我們沒有。我們的論文只是關於空氣中的DNA鏈,他們是反應過度了,也解釋過度了。」拉森教授解釋道:「細菌傳播的途徑我們都知道,例如人與人的接觸、水或食物汙染等等,通常來講,僅僅呼吸空氣不會感染細菌,甚至呼吸到被汙染的空氣也不會。但是當在不同環境之間有可移動的基因時,對細菌在空氣中傳播的可能性研究就變得更為重要。因為在我們生存的環境中,我們經常發現抗藥性基因,這些基因也許是通過空氣來傳輸的。」「人類要感染病原菌才會生病,而且需要足夠大的數量的、活的致病細菌,只有在這種條件下,人才會被感染。而(陰霾中的)這些細菌是不是活的?它們是否能夠致病?我們還沒有研究這方面。為了謹慎起見,在了解有多少活細菌、是什麼種類的細菌之前,不好談論其帶來的風險。」

人類濫用抗生素是全球議題 談到細菌的抗藥性問題,拉森教授解釋說:「人類對抗生素的濫用是全球性的重大議題。人們在並不需要的時候服用抗生素,從而使機體產生抗藥性。」「我應該說明的是,這裡有另一個領域,就是在畜牧業中使用抗生素,對動物施打抗生素,不是因為動物生病,而是用於加速動物生長,這一樣會帶來抗藥性的問題。瑞典早在1986年,歐洲在2006年,就禁止使用抗生素來加速動物生長。我認為這是中國應該著重考慮的。」此外,還有生產抗生素的那些製藥廠、廢水處理工廠等周圍環境裡都含有大量的對抗生素具有抗藥性的細菌。拉森教授目前在歐洲的研究項目,包括在這些環境下抗生素抗藥性的細菌傳播問題,希望能發現在此環境下排汙的安全限值,以及如何應對中國的製藥業的風險,因為中國和印度是世界上生產抗生素最多的國家。拉森教授表示,接下來會對陰霾裡的細菌存活情況進行研究,目前已經在進行討論。而且陰霾中的懸浮顆粒是否會提供細菌繁殖及傳播的環境,也是一個重要的課題。目前他們研究中使用的只是過濾後的北京陰霾空氣樣本。拉森教授強調,陰霾確實對健康有害,不過人們更需要擔心的不是那些使細菌產生抗藥性的基因,而是陰霾裡其它的有害成分。

Why Drug-Resistance Genes Are Showing Up In Smog   Alexandra Sifferlin @acsifferlin Dec. 8, 2016 Scientists say the spread of antibiotic resistance genes in the air needs to be explored. Antibiotic resistant bacteria is becoming a greater medical threat, with estimates suggesting that by 2050, 10 million people will die from infections that are resistant to drugs each year. In a recent study, scientists discovered the genes that make bacteria resistant to antibiotics in polluted air in China. That does not mean people can get drug-resistant infections from the air, but the aerial spread of such genes should be the subject of further study, the researchers say. The report was published in the journal Microbiome. In the study, researchers at the University of Gothenburg analyzed DNA sequencing from 864 different samples from humans, animals and the environment. A few of those samples came from the air in Beijing, and from those samples the researchers identified a variety of genes that can make bacteria resistant to antibiotics. What was especially concerning was that the researchers found genes that can contribute to a resistance to a group of "last resort" antibiotics called carbapenems."We think this is really under-investigated and not taken seriously," says study author Joakim Larsson, director of the Centre for Antibiotic Resistance Research at the University of Gothenburg. Not only did Larsson and his colleagues find evidence that genes linked to antibiotic resistance can be present in the air, but they also found a high amount of the genes in areas where there's a lot of pollution from antibiotic manufacturing. Waste from manufacturing plants can end up in water sources, as Larsson has found in other research. He says there should be more regulation when it comes to how companies dispose of their waste. "We need to apply discharge limits and have some regulation enforced," says Larsson. "I think there's sufficient data there to really call for some action. "The idea that people could contract antibiotic resistant infections from smog in China got some attention recently, but Larsson says people should not overreact to the findings. Larsson says his study is not suggesting that people are getting antibiotic resistant infections from the air, but that air should be explored as a potential way for resistance to be transmitted, rather than the diseases themselves. Antibiotic resistance genes are only problematic when they are present in live bacteria. Next, Larsson and his fellow researchers plan to study whether resistance genes can spread through air from European sewage treatment plants.

No comments:

Post a Comment