Tag: Fanny Berglund

September 2020 Pod: All antibiotic resistance

This is the fifth episode of the Microbiology Lab Pod and has been lying around on my computer almost finished for way too long. It was recorded on September 23, and the bigger-than-ever-before crew (Johan Bengtsson-Palme, Emil Burman, Haveela Kunche, Anna Abramova, Marcus Wenne, Sebastian Wettersten and Mahbuba Lubna Akter) is joined by Fanny Berglund to discuss computational discovery of novel resistance genes. We also discuss antibiotic resistance mechanisms, particularly in Pseudomonas aeruginosa.

The specific papers discussed in the pod (with approximate timings) are as follows:

  • 5:30 – Berglund, F., Johnning, A., Larsson, D.G.J., Kristiansson, E., 2020. An updated phylogeny of the metallo-b-lactamases. Journal of Antimicrobial Chemotherapy 7. https://doi.org/10.1093/jac/dkaa392
  • 5:45 – Berglund, F., Österlund, T., Boulund, F., Marathe, N.P., Larsson, D.G.J., Kristiansson, E., 2019. Identification and reconstruction of novel antibiotic resistance genes from metagenomes. Microbiome 7, 52. https://doi.org/10.1186/s40168-019-0670-1
  • 6:00 – Berglund, F., Marathe, N.P., Österlund, T., Bengtsson-Palme, J., Kotsakis, S., Flach, C.-F., Larsson, D.G.J., Kristiansson, E., 2017. Identification of 76 novel B1 metallo-β-lactamases through large-scale screening of genomic and metagenomic data. Microbiome 5, i29. https://doi.org/10.1186/s40168-017-0353-8
  • 6:15 – Boulund, F., Berglund, F., Flach, C.-F., Bengtsson-Palme, J., Marathe, N.P., Larsson, D.G.J., Kristiansson, E., 2017. Computational discovery and functional validation of novel fluoroquinolone resistance genes in public metagenomic data sets. BMC Genomics 18, 438. https://doi.org/10.1186/s12864-017-4064-0
  • 37:15 – Crippen, C.S., Jr., M.J.R., Sanchez, S., Szymanski, C.M., 2020. Multidrug Resistant Acinetobacter Isolates Release Resistance Determinants Through Contact-Dependent Killing and Bacteriophage Lysis. Frontiers in Microbiology 11. https://doi.org/10.3389/fmicb.2020.01918
  • 52:15 – Leonard, A.F.C., Zhang, L., Balfour, A.J., Garside, R., Hawkey, P.M., Murray, A.K., Ukoumunne, O.C., Gaze, W.H., 2018. Exposure to and colonisation by antibiotic-resistant E. coli in UK coastal water users: Environmental surveillance, exposure assessment, and epidemiological study (Beach Bum Survey). Environment International 114, 326–333. https://doi.org/10.1016/j.envint.2017.11.003
  • 53:30 – Bengtsson-Palme, J., Kristiansson, E., Larsson, D.G.J., 2018. Environmental factors influencing the development and spread of antibiotic resistance. FEMS Microbiology Reviews 42, 25. https://doi.org/10.1093/femsre/fux053
  • 54:30 – Leonard, A.F.C., Zhang, L., Balfour, A.J., Garside, R., Gaze, W.H., 2015. Human recreational exposure to antibiotic resistant bacteria in coastal bathing waters. Environment International 82, 92–100. https://doi.org/10.1016/j.envint.2015.02.013
  • 55:30 – Ahmed, M.N., Abdelsamad, A., Wassermann, T., et al., 2020. The evolutionary trajectories of P. aeruginosa in biofilm and planktonic growth modes exposed to ciprofloxacin: beyond selection of antibiotic resistance. npj Biofilms and Microbiomes 6. https://doi.org/10.1038/s41522-020-00138-8
  • 69:30 – Rezzoagli, C., Archetti, M., Mignot, I., Baumgartner, M., Kümmerli, R., 2020. Combining antibiotics with antivirulence compounds can have synergistic effects and reverse selection for antibiotic resistance in Pseudomonas aeruginosa. PLOS Biology 18, e3000805. https://doi.org/10.1371/journal.pbio.3000805
  • 79:45 – Allen, R.C., Popat, R., Diggle, S.P., Brown, S.P., 2014. Targeting virulence: can we make evolution-proof drugs? Nature reviews Microbiology 12, 300–308. https://doi.org/10.1038/nrmicro3232
  • 80:45 – Köhler, T., Perron, G.G., Buckling, A., van Delden, C., 2010. Quorum Sensing Inhibition Selects for Virulence and Cooperation in Pseudomonas aeruginosa. PLoS Pathogens 6, e1000883. https://doi.org/10.1371/journal.ppat.1000883

The podcast was recorded on September 23, 2020. If you want to reach out to us with comments, suggestions or other feedback, please send an e-mail to podcast at microbiology dot se or contact @bengtssonpalme via Twitter. The music that can be heard on the pod is composed by Johan Bengtsson-Palme and is taken from the album Cafe Phonocratique.

Published paper: 76 new metallo-beta-lactamases

Today, Microbiome put online a paper lead-authored by my colleague Fanny Berglund – one of Erik Kristiansson‘s brilliant PhD students – in which we identify 76 novel metallo-ß-lactamases (1). This feat was made possible because of a new computational method designed by Fanny, which uses a hidden Markov model based on known B1 metallo-ß-lactamases. We analyzed over 10,000 bacterial genomes and plasmids and over 5 terabases of metagenomic data and could thereby predict 76 novel genes. These genes clustered into 59 new families of metallo-β-lactamases (given a 70% identity threshold). We also verified the functionality of 21 of these genes experimentally, and found that 18 were able to hydrolyze imipenem when inserted into Escherichia coli. Two of the novel genes contained atypical zinc-binding motifs in their active sites. Finally, we show that the B1 metallo-β-lactamases can be divided into five major groups based on their phylogenetic origin. It seems that nearly all of the previously characterized mobile B1 β-lactamases we identify in this study were likely to have originated from chromosomal genes present in species within the Proteobacteria, particularly Shewanella spp.

This study more than doubles the number of known B1 metallo-β-lactamases. As with the study by Boulund et al. (2) which we published last month on computational discovery of novel fluoroquinolone resistance genes (which used a very similar approach but on a completely different type of genes), this study also supports the hypothesis that environmental bacterial communities act as sources of uncharacterized antibiotic resistance genes (3-7). Fanny have done a fantastic job on this paper, and I highly recommend reading it in its entirety (it’s open access so you have virtually no excuse not to). It can be found here.


  1. Berglund F, Marathe NP, Österlund T, Bengtsson-Palme J, Kotsakis S, Flach C-F, Larsson DGJ, Kristiansson E: Identification of 76 novel B1 metallo-β-lactamases through large-scale screening of genomic and metagenomic data. Microbiome, 5, 134 (2017). doi: 10.1186/s40168-017-0353-8
  2. Boulund F, Berglund F, Flach C-F, Bengtsson-Palme J, Marathe NP, Larsson DGJ, Kristiansson E: Computational discovery and functional validation of novel fluoroquinolone resistance genes in public metagenomic data sets. BMC Genomics, 18, 682 (2017). doi: 10.1186/s12864-017-4064-0
  3. Bengtsson-Palme J, Larsson DGJ: Antibiotic resistance genes in the environment: prioritizing risks. Nature Reviews Microbiology, 13, 369 (2015). doi: 10.1038/nrmicro3399-c1
  4. Allen HK, Donato J, Wang HH et al.: Call of the wild: antibiotic resistance genes in natural environments. Nature Reviews Microbiology, 8, 251–259 (2010).
  5. Berendonk TU, Manaia CM, Merlin C et al.: Tackling antibiotic resistance: the environmental framework. Nature Reviews Microbiology, 13, 310–317 (2015).
  6. Martinez JL: Bottlenecks in the transferability of antibiotic resistance from natural ecosystems to human bacterial pathogens. Frontiers in Microbiology, 2, 265 (2011).
  7. Finley RL, Collignon P, Larsson DGJ et al.: The scourge of antibiotic resistance: the important role of the environment. Clinical Infectious Diseases, 57, 704–710 (2013).