Authors affiliated with the MolMik group at time of publication are highlighted in bold. * designates joint first authors.


Minhas V, Domenech A, Synefiariodou D, Straume D, Brendel M, Cebrero G, Liu X, Costa C, Baldry M, Sirard JC, Perez C, Gisch N, Hammerschmidt S, Håvarstein LS, Veening JW. Competence remodels the pneumococcal cell wall providing resistance to fratricide and surface exposing key virulence factor. BioRxiv. 

Cacace E, Kim V, Knopp M, Tietgen M, Brauer-Nikonow A, Inecik K, Mateus A, Milanese A, Mårli MT, Mitosch K, Selkrig J, Brochado AR, Kuipers O, Kjos M, Zeller G, Savitski M, Göttig S, Huber W, Typas A. High-throughput profiling of drug interactions in Gram-positive bacteria. Preprint:

Najaf J, Gjennestad RS, Kissen R, Brembu T, Bartsova Z, Winge P, Bones AM. PAMP-Induced secreted Peptide-Like 6 (PIPL6) functions as an amplifier of plant immune 3 response through RLK7 and WRKY33 modul. Preprint:


Hauge IH, Sandegren V, Ruud Winther A, Bøe CA, Salehian Z, Håvarstein LS, Kjos M, Straume D (2023) A novel proteinaceous molecule produced by Lysinibacillus sp. OF-1 depends on the Ami oligopeptide transporter to kill Streptococcus pneumoniae. Microbiology. 169(3):001313.

Gao Y, Kjos M, Arntzen MØ, Bakken LR, Frostegård Å (2023) Denitrification by bradyrhizobia under feast and famine and the role of the bc1 complex in securing electrons for N2O reduction. Appl Environ Microbiol. Preprint:


Disen Barbuti M, Myrbråten I, Morales Angeles D, Kjos M (2022) An updated overview of the cell cycle promesses in Staphylococcus aureus. MicrobiologyOpen. In press.

Audshasai T, Coles JA, Panagiotou S, Khandaker S, Scales HE, Kjos M, Baltazar M, Vignau, Brewer JM, Kadioglu A, Yang M. Streptococcus pneumoniae rapidly translocates from the nasopharynx through the cribriform plate to invade and inflame the dura. mBio. doi/10.1128/mbio.01024-22.

Myrbråten I, Stamsås GA, Chan H, Morales Angeles D, Knutsen TM, Salehian Z, Shapaval O, Straume D, Kjos M. (2022) SmdA is a novel cell morphology determinant in Staphylococcus aureus. See also commentary:


Oftedal T, Ovchinnikov K, Hestad KA, Porcellato D, Narvhus J, Kranjec C, Kjos M, Diep DB (2021) Ubericin K, a new pore-forming bacteriocin targeting mannose-PTS. Microbiol Spectrum. 

Gallay C, Sanselicio S, Anderson ME, Soh YM, Liu X, Stamsås GA, Pelliciari S, van Raaphorst R, Dénéréaz J, Kjos M, Murray H, Gruber S, Grossman AD, Veening JW (2021). CcrZ is a spatiotemporal cell cycle regulator that interacts with FtsZ and controls DNA replication by modulating the activity of DnaA. Nat

Ovchinnikov K, Kranjec C, Telke A, Kjos M, Thorstensen T, Carlsen H, Scherer S, Diep DB (2021). A strong synergy between the thiopeptide bacteriocin micrococcin P1 and rifampicin against MRSA in a murine skin infection model . Front Immunol. 12: 676534.

Straume, D., Piechowiak, K.W., Kjos M, Håvarstein LS (2021) Class A PBPs: it is time to rethink traditional paradigms. Mol Microbiol. doi:

Ruud-Winther A., Kjos M., Herigstad M. L., Håvarstein L.S., Straume D. (2021) EloR interacts with the lytic transglycosylase MltG at midcell in Streptococcus pneumoniae R6. J Bacteriol. doi: 10.1128/JB.00691-20 Preprint available at:  

Kranjec C*, Morales-Angeles D*, Mårli MT,  Fernandez L, Garcia P, Kjos M*, Diep DB* (2021) Staphylococcal Biofilms: Challenges and novel therapeutic perspectives. Antibiotics. 10(2):131.


Stamsås G.A.*, Restelli M.*, Ducret, A., Freton C., Garcia P.S.,, Håvarstein L.S., Straume D., Grangeasse C.*, Kjos M.* (2020) A CozE homolog contributes to cell size homeostasis of Streptococcus pneumoniae. mBio, 11(5):e02461-20. doi: 10.1128/mBio.02461-20. 

Alcorlo M., Straume D., Lutkenhaus J., Håvarstein L.S., Hermoso J.A (2020). Structural characterization of the essential cell division protien FtsE and its interaction with FtsX in Streptococcus pneumoniae. mBio, 11(5):e01488-20. doi: 10.1128/mBio.01488-20

Fergestad, M.*, Stamsås, G.A.*, Morales-Angeles, D., Salehian, Z., Wasteson, Y., Kjos, M. (2020) PBP2A provides variable levels of protection towards different β-lactams in Staphylococcus aureus RN4220. Microbiol Open. 9:e1057.

Straume, D.*, Piechowiak, K.W.*, Olsen, S., Stamsås, G.A., Berg, K.H., Kjos, M., Heggenhougen, M.V., Alcorlo, M., Hermoso, J., Håvarstein, L.S. Class A PBPs have a distinct and unique role in the construction of the pneumococcal cell wall. Proc Natl Acad Sci U S A. 117 (11) 6129-6138. 


Kjos, M. (2019). Construction of fluorescent pneumococci for in vivo imaging and labelling of the chromosome. In Iovino, F. (ed.) Streptococcus pneumoniae. Methods and Protocols, pp. 41–51. New York: Humana Press. doi: 10.1007/978-1-4939-9199-0_4

Kjos, M. (2019). Transcriptional knockdown in pneumococci using CRISPR interference. In Iovino, F. (ed.) Streptococcus pneumoniae. Methods and Protocols, pp. 89–98. doi: 10.1007/978-1-4939-9199-0_8

Myrbråten, I., Will, K., Straume, D., Salehian, Z., Håvarstein, L.S., Mathiesen, G., Kjos, M. (2019). CRISPR interference for rapid knockdown of essential cell cycle genes in Lactobacillus plantarum. mSphere, 4(2): e00007–19. 

Rued, B.E., Alcorlo, M., Edmonds, K.A., Martínez-Caballero, S., Straume, D., Fu, Y., Bruce, K.E., Wu, H., Håvarstein, L.S., Hermoso, J.A., Winkler, M.E., Giedroc, D.P. (2019). Structure of the large extracellular loop of FtsX and its interaction with the essential peptidoglycan hydrolase PcsB in Streptococcus pneumoniae. mBio, 10(1): e02622–18. doi: 10.1128/mBio.02622-18

Schmidt, F., Kakar, N., Meyer, T.C., Depke, M., Masouris, I., Burchhardt, G., Gómez-Mejia, A., Dhople, V., Håvarstein, L.S., Sun, Z., Moritz, R.L., Völker, U., Koedel, U., Hammerschmidt, S. (2019). In vivo proteomics identifies the competence regulon and AliB oligopeptide transporter as pathogenic factors in pneumococcal meningitis. PLoS Pathog, 15(7): e1007987. doi: 10.1371/journal.ppat.1007987

van Raaphorst, R., Kjos, M., Veening, J.W. (2019). BactMAP: an R package for integrating, analyzing and visualizing bacterial microscopy dataMol Microbiol, 113:297-308. doi: 10.1111/mmi.14417

Winther, A.R., Kjos, M., Stamsås, G.A., Håvarstein, L.S., Straume, D. (2019). Prevention of EloR/KhpA heterodimerization by introduction of site-specific amino acid substitutions renders the essential elongasome protein PBP2b redundant in Streptococcus pneumoniaeSci Rep, 9: 3681. doi: 10.1038/s41598-018-38386-6


Lycus, P., Soriano-Laguna, M., Kjos, M., Richardson, D., Gates, A., Milligan, D.A., Frostegård, Å., Bergaust, L., Bakken, L.R. (2018). A bet-hedging strategy of denitrifying bacteria curtails their release of N2OProc Natl Acad Sci USA, 115(46):11820–11825. doi: 10.1073/pnas.1805000115

Miller, E.*, Kjos, M.*, Abrudan, M., Roberts, I.S., Veening, J.W., Rozen, D.E. (2018). Crosstalk and eavesdropping among quorum sensing peptide signals that regulate bacteriocin production in Streptococcus pneumoniaeISME J, 12(10): 2363–2375. doi: 10.1038/s41396-018-0178-x

Morlot, C., Straume, D., Peters, K., Hegnar, O.A., Simon, N., Villard, A.M., Contreras-Martel, C., Leisico, F., Breukink, E., Gravier-Pelletier, C., Le Corre, L., Vollmer, W., Pietrancosta, N., Håvarstein, L.S., Zapun, A. (2018). Structure of the essential peptidoglycan amidotransferase MurT/GatD complex from Streptococcus pneumoniae. Nat Commun, 9(1): 3180. doi: 10.1038/s41467-018-05602-w

Stamsås, G.A.*, Myrbråten, I.*, Straume, D., Salehian, Z., Veening, J.W., Håvarstein, L.S., Kjos, M. (2018). CozEa and CozEb play overlapping and essential roles in controlling cell division in Staphylococcus aureusMol Microbiol, 109(5): 615–632. doi: 10.1111/mmi.13999


Liu, X., Gallay, C., Kjos, M., Domenech, A., Slager, J., van Kessel, S., Knoops, K., Sorg, R.A., Zhang, J.R., Veening, J.W. (2017). High-throughput CRISPRi phenotyping in Streptococcus pneumoniae identifies new essential genes involved in cell wall synthesis and competence developmentMol Syst Biol, 13: 931. doi: 10.15252/msb.20167449

Moreno-Gámez, S., Sorg, R.A., Domenech, A., Kjos, M., Weissing, F.J., van Doorn, G.S., Veening, J.W. Quorum-sensing integrates environmental cues, cell density and cell history to control bacterial competence. Nat Comm, 8(1): 854. doi: 10.1038/s41467-017-00903-y

Ovchinnikov, K.V., Kristiansen, P.E., Straume, D., Jensen, M.S., Aleksandrzak-Piekarczyk, T., Nes, I.F., Diep, D.B. (2017). The leaderless bacteriocin enterocin K1 is highly potent against Enterococcus faecium: a study on structure, target spectrum and receptor. Front Microbiol, 8: 774. doi: 10.3389/fmicb.2017.00774

Stamsås, G.A., Straume, D., Ruud, Winther, A., Kjos, M., Frantzen, C.A., Håvarstein, L.S. (2017). Identification of EloR (Spr1851) as a regulator of cell elongation in Streptococcus pneumoniaeMol Microbiol, 105(6): 954–967. doi: 10.1111/mmi.13748

Stamsås, G.A., Straume, D., Salehian, Z., Håvarstein, L.S. (2017). Evidence that pneumococcal WalK is regulated by StkP through protein-protein interactionMicrobiology,163(3): 383–399. doi: 10.1099/mic.0.000404

Straume, D., Stamsås, G.A., Salehian, Z., Håvarstein, L.S. (2017). Overexpression of the fratricide immunity protein ComM leads to growth inhibition and morphological abnormalities in Streptococcus pneumoniae. Microbiology, 163(1): 9–21. doi: 10.1099/mic.0.000402

Straume, D., Stamsås, G.A., Berg, K.H., Salehian, Z., Håvarstein, L.S. (2017). Identification of pneumococcal proteins that are functionally linked to penicillin-binding protein 2b (PBP2b). Mol Microbiol, 103(1): 99–116. doi: 10.1111/mmi.13543

van Raaphorst, R.*, Kjos, M.*, Veening, J.W. (2017). Chromosome segregation drives division site selection in Streptococcus pneumoniaeProc Natl Acad Sci USA, 114(29): E5959–E5968. doi: 10.1073/pnas.1620608114


Kjos, M.*, Miller, E.*, Slager, J., Lake, F., Gericke, O., Roberts, I.S., Rozen, D.E., Veening, J.W. (2016). Expression of Streptococcus pneumoniae bacteriocins is induced by antibiotics via regulatory interplay with the competence systemPLoS Pathogens, 12(2): e1005422. doi: 10.1371/journal.ppat.1005422

Oppegård, C., Kjos, M., Veening, J.W., Nissen-Meyer, J., Kristensen, T. (2016). A putative amino acid transporter determines sensitivity to the two-peptide bacteriocin plantaricin JKMicrobiologyOpen, 5(4): 700–708. doi: 10.1002/mbo3.36


Attaiech, L., Minnen, A., Kjos, M., Gruber, S., Veening, J.W. (2015). The ParB-parS chromosome segregation system modulates natural competence development in Streptococcus pneumoniaemBio, 6(4): e00662–15. doi: 10.1128/mBio.00662-15

Beilharz, K., van Raaphorst, R., Kjos, M., Veening, J.W. (2015). Red fluorescent proteins for gene expression and protein localization studies in Streptococcus pneumoniae and efficient transformation with DNA assembled via the Gibson assembly method. Appl Environ Microbiol, 81(20): 7244–52. doi: 10.1128/AEM.02033-15

Kjos, M., Aprianto, R., Fernandes, V.E., Andrew, P.W., van Strijp, J.A.G., Nijland, R., Veening, J.W. (2015). Bright fluorescent Streptococcus pneumoniae for live cell imaging of host-pathogen interactionsJ Bacteriol, 197: 807–18. doi: 10.1128/JB.02221-14

Nourikyan, J.*, Kjos, M.*, Cluzel, C., Morlot, C., Mercy, C., Noirot-Gros, M.F., Lavergne, J.P., Guiral, S., Veening, J.W., Grangeasse, C. (2015). Autophosphorylation of the bacterial tyrosine kinase CpsD coordinates capsule synthesis and cell division of Streptococcus pneumoniaePLoS Genetics, 11(9): e1005518. doi: 10.1371/journal.pgen.1005518

Paixão, L., Oliveira, J., Verissímo, A., Vinga, S., Lourenço, E., Ventura, R., Kjos, M., Veening, J.W., Fernandes, V.E., Andrew, P.E., Yesilkaya, H., Neves, A.R. (2015). Host glycan sugar specific pathways in Streptococcus pneumoniae: galactose as a key sugar in colonisation and infectionPLoS One, 10(3): e0121042. doi: 10.1371/journal.pone.0121042

Straume, D., Stamsås, G.A., Håvarstein, L.S. (2015). Natural transformation and genome evolution in Streptococcus pneumoniae. Infect Genet Evol, 33: 371–80. doi: 10.1016/j.meegid.2014.10.020


Bartual, S.G., Straume, D., Stamsås, G.A., Muñoz, I.G., Alfonso, C., Martínez-Ripoll, M., Håvarstein, L.S., Hermoso, J.A. (2014). Structural basis of PcsB-mediated cell separation in Streptococcus pneumoniae. Nat Commun, 5: 3842. doi: 10.1038/ncomms4842

Berg, K.H., Straume, D., Håvarstein, L.S. (2014). The function of the transmembrane and cytoplasmic domains of pneumococcal penicillin-binding proteins 2x and 2b extends beyond that of simple anchoring devices. Microbiology, 160(8): 1585–98. doi: 10.1099/mic.0.078535-0

Fagerlund, A., Granum, P.E., Håvarstein, L.S. (2014). Staphylococcus aureus competence genes: mapping of the SigH, ComK1 and ComK2 regulons by transcriptome sequencing. Mol Microbiol, 94(3): 557–79. doi: 10.1111/mmi.12767

Hassan, M., Kjos, M., Nes, I.F., Diep, D.B., Lotfipour, F. (2014). Antimicrobial peptides from prokaryotes. In Phoenix, D.A., Harris, F., Dennison, S.R., (eds.) Novel Antimicrobial Agents and Strategies, pp. 71–90. Germany: Wiley‐VCH Verlag GmbH & Co. doi: 10.1002/9783527676132.ch5

Kjos, M.*, Oppegård, C.*, Diep, D.B., Nes, I.F., Veening, J.W., Nissen-Meyer, J., Kristiansen, T. (2014). Sensitivity to the two-peptide bacteriocin lactococcin G is dependent on an enzyme involved in cell-wall synthesisMol Microbiol, 92(6): 1177–87. doi: 10.1111/mmi.12632

Kjos, M., Veening, J.W. (2014). Tracking of chromosome dynamics in live Streptococcus pneumoniae reveals that transcription promotes chromosome segregationMol Microbiol, 91(6): 1088–1105. doi: 10.1111/mmi.12517

Slager, J., Kjos, M., Attaiech, L., Veening, J.W. (2014). Antibiotic-induced increase of origin proximal gene copy number triggers bacterial competenceCell, 157(2): 395–406. doi: 10.1016/j.cell.2014.01.068


Berg, K.H., Stamsås, G.A., Straume, D., Håvarstein, L.S. (2013). Effects of low PBP2b levels on cell morphology and peptidoglycan composition in Streptococcus pneumoniae R6J Bacteriol, 195(19): 4342–54. doi: 10.1128/JB.00184-13

Pinho, M.G., Kjos, M., Veening, J.W. (2013). How to get (a)round: mechanisms controlling growth and division of coccoid bacteriaNat Rev Microbiol, 11: 601–14. doi: 10.1038/nrmicro3088

Stamsås, G.A., Håvarstein, L.S., Straume, D. (2013). CHiC, a new tandem affinity tag for the protein purification toolbox. J Microbiol Methods, 92(1): 59–63. doi: 10.1016/j.mimet.2012.11.003


Berg, K.H., Biørnstad, T.J., Johnsborg, O., Håvarstein, L.S. (2012). Properties and biological role of streptococcal fratricins. Appl Environ Microbiol, 78(10): 3515–22. doi: 10.1128/AEM.00098-12

Berg, K.H., Ohnstad, H.S., Håvarstein, L.S. (2012). LytF, a novel competence-regulated murein hydrolase in the genus Streptococcus. J Bacteriol, 194(3): 627–35. doi: 10.1128/JB.06273-11

Biørnstad, T.J., Ohnstad, H.S., Håvarstein, L.S. (2012). Deletion of the murein hydrolase CbpD reduces transformation efficiency in Streptococcus thermophilus. Microbiology, 158(4): 877–85. doi: 10.1099/mic.0.056150-0

Eberhardt, A., Hoyland, C.N., Vollmer, D., Bisle, S., Cleverley, R.M., Johnsborg, O., Håvarstein, L.S., Lewis, R.J., Vollmer, W. (2012). Attachment of capsular polysaccharide to the cell wall in Streptococcus pneumoniae. Microb Drug Resist, 18(3): 240–55. doi: 10.1089/mdr.2011.0232

Hassan, M., Kjos, M., Nes, I.F., Diep, D.B., Lotfipour, F. (2012). Natural antimicrobial peptides from bacteria: characteristics and potential applications to fight against antibiotic resistanceJ Appl Microbiol, 113(4): 723–36. doi: 10.1111/j.1365-2672.2012.05338.x

Wei, H., Håvarstein, L.S. (2012). Fratricide is essential for efficient gene transfer between pneumococci in biofilms. Appl Environ Microbiol, 78(16): 5897–905. doi: 10.1128/AEM.01343-12


Berg, K.H., Biørnstad, T.J., Straume, D., Håvarstein, L.S. (2011). Peptide-regulated gene depletion system developed for use in Streptococcus pneumoniae. J Bacteriol, 193(19): 5207–15. doi: 10.1128/JB.05170-11

Biørnstad, T.J., Håvarstein, L.S. (2011). ClpC acts as a negative regulator of competence in Streptococcus thermophilus. Microbiology, 157(6): 1676–84. doi: 10.1099/mic.0.046425-0

Kjos, M., Borrero, J., Opsata, M., Birri, D.J., Holo, H., Cintas, L.M., Snipen, L., Hernandez, P.E., Nes, I.F., Diep, D.B. (2011). Target recognition, resistance, immunity and genome mining of class II bacteriocins from Gram-positive bacteriaMicrobiology, 157: 3256–67. doi: 10.1099/mic.0.052571-0

Kjos, M., Nes, I.F., Diep, D.B. (2011). Mechanisms of resistance to bacteriocins targeting the mannose phosphotransferase systemAppl Environ Microbiol, 77(10): 3335–42. doi: 10.1128/AEM.02602-10

Nes, I.F., Kjos, M., Diep, D.B. (2011). Antimicrobial components of lactic acid bacteria. In Lahtinen, S., Ouwehand, A.C., Salminen, S., von Wright, A. (eds.) Lactic acid bacteria: microbiological and functional aspects (4th ed.), pp. 286–311. Boca Raton: CRC Press. doi: 10.1201/b11503


Blomqvist, T., Steinmoen, H., Håvarstein, L.S. (2010).  A food-grade site-directed mutagenesis system for Streptococcus thermophilus LMG 18311. Lett Appl Microbiol, 50(3): 314–9. doi: 10.1111/j.1472-765X.2009.02794.x

Eldholm, V., Johnsborg, O., Straume, D., Ohnstad, H.S., Berg, K.H., Hermoso, J.A., Håvarstein, L.S. (2010). Pneumococcal CbpD is a murein hydrolase that requires a dual cell envelope binding specificity to kill target cells during fratricide. Mol Microbiol, 76(4): 905–17. doi: 10.1111/j.1365-2958.2010.07143.x

Eldholm, V., Gutt, B., Johnsborg, O., Brückner, R., Maurer, P., Hakenbeck, R., Mascher, T., Håvarstein, L.S. (2010). Pneumococcal CbpD is a murein hydrolase that requires a dual cell envelope binding specificity to kill target cells during fratricide. J Bacteriol, 192(7): 1761–73. doi: 10.1128/JB.01489-09

Håvarstein, L.S. (2010). Increasing competence in the genus Streptococcus. Mol Microbiol, 78(3): 541–4. doi: 10.1111/j.1365-2958.2010.07380.x

Kjos, M., Salehian, Z., Nes, I.F., Diep, D.B. (2010). An extracellular loop of the mannose phosphotransferase system component IIC is responsible for specific targeting by class IIa bacteriocinsJ Bacteriol, 192(22): 5906–13. doi: 10.1128/JB.00777-10

Kjos, M., Snipen, L.S., Salehian, Z., Nes, I.F., Diep, D.B. (2010). The Abi proteins and their involvement in bacteriocin self-immunityJ Bacteriol, 192(8): 2068–76. doi: 10.1128/JB.01553-09


Diep, D.B., Straume, D., Kjos, M., Torres, C., Nes, I.F. (2009). An overview of the mosaic bacteriocin pln loci from Lactobacillus plantarumPeptides, 30 (8): 1562–74. doi: 10.1016/j.peptides.2009.05.014

Eldholm, V., Johnsborg, O., Haugen, K., Ohnstad, H.S., Håvarstein, L.S. (2009). Fratricide in Streptococcus pneumoniae: contributions and role of the cell wall hydrolases CbpD, LytA and LytC. Microbiology, 155(7): 2223–34. doi: 10.1099/mic.0.026328-0

Johnsborg, O., Håvarstein, L.S. (2009). Pneumococcal LytR, a protein from the LytR-CpsA-Psr family, is essential for normal septum formation in Streptococcus pneumoniae. J Bacteriol, 191(18): 5859–64. doi: 10.1128/JB.00724-09

Kjos, M., Nes, I.F., Diep, D.B. (2009). Class II one-peptide bacteriocins target a phylogenetically defined subgroup of mannose phosphotransferase systems on sensitive cellsMicrobiology, 155(9): 2949–61. doi: 10.1099/mic.0.030015-0

Straume, D., Johansen, R.F., Bjørås, M., Nes, I.F., Diep, D.B. DNA binding kinetics of two response regulators, PlnC and PlnD, from the bacteriocin regulon of Lactobacillus plantarum C11. BMC Biochem, 10:17. doi: 10.1186/1471-2091-10-17

Published 25. November 2019 - 11:08 - Updated 13. March 2023 - 17:04