The structure and diversity of human, animal and environmental resistomes

Pal, Chandan; Bengtsson‐Palme, Johan; Kristiansson, Erik; Larsson, D. G. Joakim

doi:10.1186/s40168-016-0199-5

Cited by 393 publications

(282 citation statements)

References 83 publications

Supporting

Mentioning

251

Contrasting

Unclassified

Order By: Relevance

“…Consequently, co-selection by antibiotics is not the prime reason of widespread copper and arsenic resistance in bacteria. In fact, more ancient and widespread selection pressures are likelihood reasons for such resistance, and in line with our finding of heavy metal resistance genes across taxa (Pal et al 2015) and metagenomes (Pal et al 2016). This principally also excludes recent uses of heavy metals by humans, and thereby elevated exposure in some bacterial communities, as a major driving force.…”

Section: Results and Conclusionsupporting

confidence: 88%

See 1 more Smart Citation

Bacterial resistance to arsenic protects against protist killing

Hao

Pal

et al. 2017

Biometals

Self Cite

View full text Add to dashboard Cite

Protists kill their bacterial prey using toxic metals such as copper. Here we hypothesize that the metalloid arsenic has a similar role. To test this hypothesis, we examined intracellular survival of Escherichia coli (E. coli) in the amoeba Dictyostelium discoideum (D. discoideum). Deletion of the E. coli ars operon led to significantly lower intracellular survival compared to wild type E. coli. This suggests that protists use arsenic to poison bacterial cells in the phagosome, similar to their use of copper. In response to copper and arsenic poisoning by protists, there is selection for acquisition of arsenic and copper resistance genes in the bacterial prey to avoid killing. In agreement with this hypothesis, both copper and arsenic resistance determinants are widespread in many bacterial taxa and environments, and they are often found together on plasmids. A role for heavy metals and arsenic in the ancient predator–prey relationship between protists and bacteria could explain the widespread presence of metal resistance determinants in pristine environments.

show abstract

Section: Results and Conclusionsupporting

confidence: 88%

“…Metal resistance genes are ubiquitous in bacterial communities across different environments and occur in many different phyla (Pal et al 2015, 2016). Based on the analyses of 4582 fully sequenced plasmids, common occurrence of copper, arsenic and silver resistance genes have been reported (Fig.…”

Section: Results and Conclusionmentioning

confidence: 99%

Bacterial resistance to arsenic protects against protist killing

Hao

Pal

et al. 2017

Biometals

Self Cite

View full text Add to dashboard Cite

show abstract

“…This diversity is known to be especially large in environments with an antibiotic selection pressure, such as environments polluted with antibiotics from the production of pharmaceuticals and wastewater treatment plants [13–15]. In addition to the already known resistance genes, bacterial communities also harbor a wide range of novel resistance determinants that have yet to be encountered in clinical settings [16–18].…”

Section: Introductionmentioning

confidence: 99%

Identification of 76 novel B1 metallo-β-lactamases through large-scale screening of genomic and metagenomic data

et al. 2017

Self Cite

View full text Add to dashboard Cite

BackgroundMetallo-β-lactamases are bacterial enzymes that provide resistance to carbapenems, the most potent class of antibiotics. These enzymes are commonly encoded on mobile genetic elements, which, together with their broad substrate spectrum and lack of clinically useful inhibitors, make them a particularly problematic class of antibiotic resistance determinants. We hypothesized that there is a large and unexplored reservoir of unknown metallo-β-lactamases, some of which may spread to pathogens, thereby threatening public health. The aim of this study was to identify novel metallo-β-lactamases of class B1, the most clinically important subclass of these enzymes.ResultsBased on a new computational method using an optimized hidden Markov model, we analyzed over 10,000 bacterial genomes and plasmids together with more than 5 terabases of metagenomic data to identify novel metallo-β-lactamase genes. In total, 76 novel genes were predicted, forming 59 previously undescribed metallo-β-lactamase gene families. The ability to hydrolyze imipenem in an Escherichia coli host was experimentally confirmed for 18 of the 21 tested genes. Two of the novel B1 metallo-β-lactamase genes contained atypical zinc-binding motifs in their active sites, which were previously undescribed for metallo-β-lactamases. Phylogenetic analysis showed that B1 metallo-β-lactamases could be divided into five major groups based on their evolutionary origin. Our results also show that, except for one, all of the previously characterized mobile B1 β-lactamases are likely to have originated from chromosomal genes present in Shewanella spp. and other Proteobacterial species.ConclusionsThis study more than doubles the number of known B1 metallo-β-lactamases. The findings have further elucidated the diversity and evolutionary history of this important class of antibiotic resistance genes and prepare us for some of the challenges that may be faced in clinics in the future.Electronic supplementary materialThe online version of this article (10.1186/s40168-017-0353-8) contains supplementary material, which is available to authorized users.

show abstract

“…Виды микроорганиз-мов, характерные для влагалища, обнаружены в тканях плаценты, околоплодной жидкости и плода [6]. Однако, по результатам сравнения состава микробиоты плацен-ты с микробиотой кишечника, полости рта, носа и вла-галища, наибольшее сходство определялось с микро-биотой полости рта [7,8]. В связи с этим представляет интерес выявленная некоторыми исследователями ассо-циация между воспалительными процессами в полости рта у беременных и преждевременными родами [9].…”

Section: актуальностьunclassified