摘要

人类不仅在医学领域而且例如在农业和畜牧业中作为生长因子使用大量抗生素，导致环境污染。即使当病原细菌成为抗生素的靶标时，数百种非致病性细菌也会受到影响。因此，致病细菌和非致病细菌都已逐渐对抗生素产生抗性。我们测试了是否仍然同时存在抗药性和毒力决定因素。我们对来自世界各地不同个体和不同人群的环境和人类肠道元基因组进行了比较研究。我们在元基因组中发现了多种多样的抗生素抗性决定因素（AR多样性[ARd]）和毒力因子（VF多样性[VFd]）。重要的是，即使校正了蛋白质家族的丰富度，ARd和VFd之间也存在相关性。与更多样化的环境相比，人类肠道中的ARd和VFd更少，但是ARd和VFd之间的相关性更强。它们的变化范围很广，从马拉维的无人看管消费量很高，到未接触的美洲印第安人人群中都不存在。我们得出结论，在人类肠道微生物区系中同时存在抗药性和毒力决定因素，这表明可能存在共选择机制。

重要性每年，不仅在人类和动物健康中，而且在牲畜中，作为生长促进剂，都使用了数千吨抗生素。因此，在过去的75年中，已在人类和环境微生物群落中选择了具有抗药性的细菌菌株。这意味着，即使当致病菌成为抗生素的靶标时，数百种非致病菌也会受到影响。在这里，我们对来自不同个体和世界各地不同人群的环境和人类肠道微生物群落进行了比较研究。我们发现抗生素耐药性和致病性是相关的，并推测通过选择耐药菌，我们可能会选择更具毒性的菌株作为抗菌治疗的副作用。

Human beings have used large amounts of antibiotics, not only in medical contexts but also, for example, as growth factors in agriculture and livestock, resulting in the contamination of the environment. Even when pathogenic bacteria are the targets of antibiotics, hundreds of nonpathogenic bacterial species are affected as well. Therefore, both pathogenic and nonpathogenic bacteria have gradually become resistant to antibiotics. We tested whether there is still cooccurrence of resistance and virulence determinants. We performed a comparative study of environmental and human gut metagenomes from different individuals and from distinct human populations across the world. We found a great diversity of antibiotic resistance determinants (AR diversity [ARd]) and virulence factors (VF diversity [VFd]) in metagenomes. Importantly there is a correlation between ARd and VFd, even after correcting for protein family richness. In the human gut, there are less ARd and VFd than in more diversified environments, and yet correlations between the ARd and VFd are stronger. They can vary from very high in Malawi, where antibiotic consumption is unattended, to nonexistent in the uncontacted Amerindian population. We conclude that there is cooccurrence of resistance and virulence determinants in human gut microbiomes, suggesting a possible coselective mechanism.

IMPORTANCE Every year, thousands of tons of antibiotics are used, not only in human and animal health but also as growth promoters in livestock. Consequently, during the last 75 years, antibiotic-resistant bacterial strains have been selected in human and environmental microbial communities. This implies that, even when pathogenic bacteria are the targets of antibiotics, hundreds of nonpathogenic bacterial species are also affected. Here, we performed a comparative study of environmental and human gut microbial communities issuing from different individuals and from distinct human populations across the world. We found that antibiotic resistance and pathogenicity are correlated and speculate that, by selecting for resistant bacteria, we may be selecting for more virulent strains as a side effect of antimicrobial therapy.

https://msphere.asm.org/content/4/3/e00135-19.abstract