10月出版的《微生物學(xué)》雜志上的一篇文章認(rèn)為,，用來殺滅環(huán)境中細(xì)菌的化學(xué)藥品會讓細(xì)菌變得更強(qiáng)壯。低濃度的這些化學(xué)藥品,，也稱抗微生物劑,，會讓金黃色葡萄球菌把這些毒性化學(xué)物質(zhì)從它們體內(nèi)有效清除掉，這樣它們有可能會對一些抗生素產(chǎn)生耐藥,。
抗微生物劑被用在消毒劑和防腐劑中以殺死微生物,。通常用來清洗醫(yī)院和家庭的環(huán)境、消毒醫(yī)療設(shè)備以及手術(shù)前的皮膚消毒,?？刮⑸飫┰谝欢◤?qiáng)度下可殺死細(xì)菌和其它的微生物。但是,，如果使用的量不夠,，細(xì)菌將會繼續(xù)生存并對治療產(chǎn)生耐受。
“像金黃色葡萄球菌會制作將多種毒性化學(xué)物質(zhì)泵出細(xì)菌體外的蛋白,，干擾抗生素對它們的治療效果,。”美國退役軍人事物醫(yī)療中心的格倫.卡特茲說,。“這些能排出毒性化學(xué)物質(zhì)的蛋白泵也可將抗生素從細(xì)菌里移出去,，使得細(xì)菌對這些藥物產(chǎn)生耐藥。我們對抗微生物劑能否也會使細(xì)菌在這些蛋白泵作用下而不會被殺死進(jìn)行了研究,。”
研究人員將從患者血液中提取的金黃色葡萄球菌放到幾種低濃度抗微生物劑和染料中,，這些抗微生物劑是醫(yī)院經(jīng)常用到的,。他們發(fā)現(xiàn),，變異讓這些細(xì)菌產(chǎn)生了較正常更多的蛋白泵。
“我們發(fā)現(xiàn),，暴露在各種低濃度的抗微生物制劑和染料中造成了細(xì)菌耐受變異體的出現(xiàn),。” 卡特茲說,。“細(xì)菌中蛋白泵的數(shù)量增加了,。由于這些蛋白泵也能清除細(xì)菌里的抗生素，有大量蛋白泵的致病菌對患者就會造成威脅，因?yàn)樗鼈儗股氐哪褪芰Ω鼜?qiáng),。”
假如細(xì)菌重復(fù)不斷地暴露于抗微生物劑中,，它們就會對消毒劑和抗生素產(chǎn)生耐受,。這些細(xì)菌多是產(chǎn)生醫(yī)院獲得性感染的細(xì)菌,。
“科學(xué)家正在嘗試研制蛋白泵抑制劑,。有效的抑制劑將會降低細(xì)菌產(chǎn)生耐受的可能性。” 卡特茲說,。“遺憾的是到目前為止一些被評估的抑制劑對各種病原體沒有效果,，因此它們在預(yù)防耐受方面不理想,。”
“合理使用抗生素，并且使用不被蛋白泵識別的抗微生物劑將會減少耐藥菌株的產(chǎn)生。” 卡特茲說,。“換句話說,，蛋白泵抑制劑結(jié)合抗生素或消毒劑將會減少這些菌株的出現(xiàn)和它們對臨床產(chǎn)生的不良影響。”（生物谷Bioon.com）
生物谷推薦原始出處：
Microbiology 154 (2008), 3144-3153; DOI 10.1099/mic.0.2008/021188-0
Multidrug efflux pump overexpression in Staphylococcus aureus after single and multiple in vitro exposures to biocides and dyes
Aurélie A. Huet1,3, Jose L. Raygada2, Kabir Mendiratta1, Susan M. Seo2 and Glenn W. Kaatz1,2
1 John D. Dingell Department of Veterans Affairs Medical Center, Detroit, MI 48201, USA
2 Department of Medicine, Division of Infectious Diseases, Wayne State University School of Medicine, Detroit, MI 48201, USA
3 École Supérieure de Microbiologie et Sécurité Alimentaire de Brest, Université de Bretagne Occidentale, Technopôle Brest-Iroise, 29280 Plouzané, France
Biocides and dyes are commonly employed in hospital and laboratory settings. Many of these agents are substrates for multiple-drugresistance (MDR)-conferring efflux pumps of both Gram-positive and Gram-negative organisms. Several such pumps have been identified inStaphylococcus aureus, and mutants overexpressing the NorA and MepA MDR pumps following exposure to fluoroquinolones have been identified. The effect of exposure to low concentrations of biocides and dyes on the expression of specific pump genes has not been evaluated. Using quantitative reverse-transcription PCR we found that exposure of clinical isolates to low concentrations of a variety of biocides and dyes in a single step, or to gradually increasing concentrations over several days, resulted in the appearance of mutants overexpressing mepA, mdeA, norA and norC, with mepA overexpression predominating. Overexpression was frequently associated with promoter-region or regulatory protein mutations. Mutants having significant increases in MICs of common pump substrates but no changes in expression of studied pump genes were also observed; in these cases changes in expression of as-yet-unidentified MDR pump genes may have occurred. Strains of S. aureus that exist in relatively protected environments and are repeatedly exposed to sublethal concentrations of biocides can develop efflux-related resistance to those agents, and acquisition of such strains poses a threat to patients treated with antimicrobial agents that are also substrates for those pumps, such as ciprofloxacin and moxifloxacin.
