Review Article | Published:

Interplay between β-lactamases and new β-lactamase inhibitors


Resistance to β-lactam antibiotics in Gram-negative bacteria is commonly associated with production of β-lactamases, including extended-spectrum β-lactamases (ESBLs) and carbapenemases belonging to different molecular classes: those with a catalytically active serine and those with at least one active-site Zn2+ to facilitate hydrolysis. To counteract the hydrolytic activity of these enzymes, combinations of a β-lactam with a β-lactamase inhibitor (BLI) have been clinically successful. However, some β-lactam–BLI combinations have lost their effectiveness against prevalent Gram-negative pathogens that produce ESBLs, carbapenemases or multiple β-lactamases in the same organism. In this Review, descriptions are provided for medically relevant β-lactamase families and various BLI combinations that have been developed or are under development. Recently approved inhibitor combinations include the inhibitors avibactam and vaborbactam of the diazabicyclooctanone and boronic acid inhibitor classes, respectively, as new scaffolds for future inhibitor design.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Additional information

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Related links


  1. 1.

    Bush, K. & Bradford, P. A. in Antibiotics and Antibiotic Resistance (eds Silver, L. L. & Bush, K.) 23–44 (Cold Spring Harbor Laboratory Press, 2016).

  2. 2.

    Waxman, D. J., Yocum, R. R. & Strominger, J. L. Penicillins and cephalosporins are active site-directed acylating agents: evidence in support of the substrate analogue hypothesis. Phil. Trans. R. Soc. Lond. B 289, 257–271 (1980).

  3. 3.

    Spratt, B. G. & Cromie, K. D. Penicillin-binding proteins of gram-negative bacteria. Rev. Infect. Dis. 10, 699–711 (1988).

  4. 4.

    Knox, J. R. Extended-spectrum and inhibitor-resistant TEM-type β-lactamases: mutations, specificity, and three-dimensional structure. Antimicrob. Agents Chemother. 39, 2593–2601 (1995).

  5. 5.

    Palzkill, T. Metallo-β-lactamase structure and function. Ann. NY Acad. Sci 1277, 91–104 (2013).

  6. 6.

    Rammelkamp, C. H. & Maxon, T. Resistance of Staphylococcus aureus to the action of penicillin. Proc. Soc. Exp. Biol. Med. 51, 386–389 (1942).

  7. 7.

    Kirby, W. M. Extraction of a highly potent penicillin inactivator from penicillin resistant staphylococci. Science 99, 452–453 (1944).

  8. 8.

    Bush, K. Past and present perspectives on β-lactamases. Antimicrob. Agents Chemother. 62, e01076–18 (2018).

  9. 9.

    Reading, C. & Cole, M. Clavulanic acid: a beta-lactamase-inhiting beta-lactam from Streptomyces clavuligerus. Antimicrob. Agents Chemother. 11, 852–857 (1977).This paper provides a description of the first BLI that was developed as a commercial product.

  10. 10.

    Ambler, R. P. The structure of β-lactamases. Phil. Trans. R. Soc. Lond. B 289, 321–331 (1980).This article is the original paper outlining the molecular classification of β-lactamases.

  11. 11.

    Bush, K., Jacoby, G. A. & Medeiros, A. A. A functional classification scheme for β-lactamases and its correlation with molecular structure. Antimicrob. Agents Chemother. 39, 1211–1233 (1995).This classic paper correlates the molecular and functional classification schemes of β-lactamases, augmenting the Ambler classes.

  12. 12.

    Bush, K. & Jacoby, G. A. Updated functional classification of β-lactamases. Antimicrob. Agents Chemother. 54, 969–976 (2010).

  13. 13.

    Jacoby, G. A. β-lactamase nomenclature. Antimicrob. Agents Chemother. 50, 1123–1129 (2006).This excellent presentation provides the background for the somewhat eclectic collection of β-lactamase names.

  14. 14.

    Beceiro, A. et al. False extended-spectrum β-lactamase phenotype in clinical isolates of Escherichia coli associated with increased expression of OXA-1 or TEM-1 penicillinases and loss of porins. J. Antimicrob. Chemother. 66, 2006–2010 (2011).

  15. 15.

    Raquet, X. et al. TEM β-lactamase mutants hydrolysing third-generation cephalosporins. A kinetic and molecular modelling analysis. J. Mol. Biol. 244, 625–639 (1994).

  16. 16.

    Livermore, D. M. et al. CTX-M: changing the face of ESBLs in Europe. J. Antimicrob. Chemother. 59, 165–174 (2007).

  17. 17.

    Bonnet, R. Growing group of extended-spectrum β-lactamases: the CTX-M enzymes. Antimicrob. Agents Chemother. 48, 1–14 (2004).

  18. 18.

    Poirel, L., Gniadkowski, M. & Nordmann, P. Biochemical analysis of the ceftazidime-hydrolysing extended-spectrum beta-lactamase CTX-M-15 and of its structurally related β-lactamase CTX-M-3. J. Antimicrob. Chemother. 50, 1031–1034 (2002).

  19. 19.

    Levasseur, P., Girard, A.-M., Miossec, C., Pace, J. & Coleman, K. In vitro antibacterial activity of the ceftazidime-avibactam combination against Enterobacteriaceae, including strains with well-characterized β-lactamases. Antimicrob. Agents Chemother. 59, 1931–1934 (2015).

  20. 20.

    Karlowsky, J. A. et al. In vitro activity of imipenem/relebactam against Gram-negative ESKAPE pathogens isolated in 17 European countries: 2015 SMART surveillance programme. J. Antimicrob. Chemother. 73, 1872–1879 (2018).

  21. 21.

    Lomovskaya, O. et al. Vaborbactam: spectrum of beta-lactamase inhibition and impact of resistance mechanisms on activity in Enterobacteriaceae. Antimicrob. Agents Chemother. 61, e01443–17 (2017).

  22. 22.

    Canton, R., Gonzalez-Alba, J. M. & Galan, J. C. CTX-M enzymes: origin and diffusion. Front. Microbiol. 3, 110 (2012).

  23. 23.

    Paterson, D. L. & Bonomo, R. A. Extended-spectrum β-lactamases: a clinical update. Clin. Microbiol. Rev. 18, 657–686 (2005).

  24. 24.

    Naas, T., Poirel, L. & Nordmann, P. Minor extended-spectrum β-lactamases. Clin. Microbiol. Infect. 14 (Suppl. 1), 42–52 (2008).

  25. 25.

    Bradford, P. A. Extended-spectrum β-lactamases in the 21st century: characterization, epidemiology, and detection of this important resistance threat. Clin. Microbiol. Rev. 14, 933–951 (2001).

  26. 26.

    Bradford, P. A. et al. Emergence of carbapenem-resistant Klebsiella species possessing the class A carbapenem-hydrolyzing KPC-2 and inhibitor-resistant TEM-30 β-lactamases in New York City. Clin. Infect. Dis. 39, 55–60 (2004).

  27. 27.

    Lahiri, S. D., Bradford, P. A., Nichols, W. W. & Alm, R. A. Structural and sequence analysis of class A beta-lactamases with respect to avibactam inhibition: impact of omega-loop variations. J. Antimicrob. Chemother. 71, 2848–2855 (2016).

  28. 28.

    Canton, R., Morosini, M. I., de la Maza, O. M. & de la Pedrosa, E. G. IRT and CMT β-lactamases and inhibitor resistance. Clin. Microbiol. Infect. 14 (Suppl. 1), 53–62 (2008).

  29. 29.

    Bret, L. et al. Inhibitor-resistant TEM (IRT) β-lactamases with different substitutions at position 244. Antimicrob. Agents Chemother. 41, 2547–2549 (1997).

  30. 30.

    Bonomo, R. A. & Rice, L. B. Inhibitor resistant class A β-lactamases. Front. Biosci. 4, e34–e41 (1999).

  31. 31.

    Queenan, A. M. & Bush, K. Carbapenemases: the versatile β-lactamases. Clin. Microbiol. Rev. 20, 440–458 (2007).

  32. 32.

    Nordmann, P. & Poirel, L. The difficult-to-control spread of carbapenemase producers among Enterobacteriaceae worldwide. Clin. Microbiol. Infect. 20, 821–830 (2014).

  33. 33.

    Kazmierczak, K. M. et al. Global dissemination of bla KPC into bacterial species beyond Klebsiella pneumoniae and in vitro susceptibility to ceftazidime-avibactam and aztreonam-avibactam. Antimicrob. Agents Chemother. 60, 4490–4500 (2016).

  34. 34.

    Frase, H., Shi, Q., Testero, S. A., Mobashery, S. & Vakulenko, S. B. Mechanistic basis for the emergence of catalytic competence against carbapenem antibiotics by the GES family of β-lactamases. J. Biol. Chem. 284, 29509–29513 (2009).

  35. 35.

    Rasmussen, B. A. et al. Characterization of IMI-1 β-lactamase, a class A carbapenem-hydrolyzing enzyme from Enterobacter cloacae. Antimicrob. Agents Chemother. 40, 2080–2086 (1996).

  36. 36.

    Naas, T., Vandel, L., Sougakoff, W., Livermore, D. M. & Nordmann, P. Cloning and sequence analysis of the gene for a carbapenem-hydrolyzing class A β-lactamase, Sme-1, from Serratia marcescens S6. Antimicrob. Agents Chemother. 38, 1262–1270 (1994).

  37. 37.

    Queenan, A. M. et al. SME-type carbapenem-hydrolyzing class A β-lactamases from geographically diverse Serratia marcescens strains. Antimicrob. Agents Chemother. 44, 3035–3039 (2000).

  38. 38.

    Garau, G., Di Guilmi, A. M. & Hall, B. G. Structure-based phylogeny of the metallo-β-lactamases. Antimicrob. Agents Chemother. 49, 2778–2784 (2005).

  39. 39.

    Kazmierczak, K. M. et al. Multiyear, multinational survey of the incidence and global distribution of metallo-β-lactamase-producing Enterobacteriaceae and Pseudomonas aeruginosa. Antimicrob. Agents Chemother. 60, 1067–1078 (2016).

  40. 40.

    Watanabe, M., Iyobe, S., Inoue, M. & Mitsuhashi, S. Transferable imipenem resistance in Pseudomonas aeruginosa. Antimicrob. Agents Chemother. 35, 147–151 (1991).

  41. 41.

    Lauretti, L. et al. Cloning and characterization of bla VIM, a new integron-borne metallo-β-lactamase gene from a Pseudomonas aeruginosa clinical isolate. Antimicrob. Agents Chemother. 43, 1584–1590 (1999).

  42. 42.

    Yong, D. et al. Characterization of a new metallo-β-lactamase gene, bla NDM-1, and a novel erythromycin esterase gene carried on a unique genetic structure in Klebsiella pneumoniae sequence type 14 from India. Antimicrob. Agents Chemother. 53, 5046–5054 (2009).

  43. 43.

    Toleman, M. A. et al. Molecular characterization of SPM-1, a novel metallo-β-lactamase isolated in Latin America: report from the SENTRY antimicrobial surveillance programme. J. Antimicrob. Chemother. 50, 673–679 (2002).

  44. 44.

    Gales, A. C., Menezes, L. C., Silbert, S. & Sader, H. S. Dissemination in distinct Brazilian regions of an epidemic carbapenem-resistant Pseudomonas aeruginosa producing SPM metallo-β-lactamase. J. Antimicrob. Chemother. 52, 699–702 (2003).

  45. 45.

    Castanheira, M., Toleman, M. A., Jones, R. N., Schmidt, F. J. & Walsh, T. R. Molecular characterization of a β-lactamase gene, bla GIM-1, encoding a new subclass of metallo-β-lactamase. Antimicrob. Agents Chemother. 48, 4654–4661 (2004).

  46. 46.

    Wendel, A. F. et al. Genetic characterization and emergence of the metallo-β-lactamase GIM-1 in Pseudomonas spp. and Enterobacteriaceae during a long-term outbreak. Antimicrob. Agents Chemother. 57, 5162–5165 (2013).

  47. 47.

    Jacoby, G. A. AmpC β-lactamases. Clin. Microbiol. Rev. 22, 161–182 (2009).

  48. 48.

    Philippon, A., Arlet, G. & Jacoby, G. A. Plasmid-determined AmpC-type β-lactamases. Antimicrob. Agents Chemother. 46, 1–11 (2002).

  49. 49.

    Alvarez, M., Tran, J. H., Chow, N. & Jacoby, G. A. Epidemiology of conjugative plasmid-mediated AmpC β-lactamases in the United States. Antimicrob. Agents Chemother. 48, 533–537 (2004).

  50. 50.

    Bradford, P. A. et al. Imipenem resistance in Klebsiella pneumoniae is associated with the combination of ACT-1, a plasmid-mediated AmpC β-lactamase, and the loss of an outer membrane protein. Antimicrob. Agents Chemother. 41, 563–569 (1997).

  51. 51.

    Wang, X. D., Cai, J. C., Zhou, H. W., Zhang, R. & Chen, G. X. Reduced susceptibility to carbapenems in Klebsiella pneumoniae clinical isolates associated with plasmid-mediated β-lactamase production and OmpK36 porin deficiency. J. Med. Microbiol. 58, 1196–1202 (2009).

  52. 52.

    Armand-Lefèvre, L. et al. Imipenem resistance in Salmonella enterica serovar Wien related to porin loss and CMY-4 β-lactamase production. Antimicrob. Agents Chemother. 47, 1165–1168 (2003).

  53. 53.

    Poirel, L., Naas, T. & Nordmann, P. Diversity, epidemiology, and genetics of class D β-lactamases. Antimicrob. Agents Chemother. 54, 24–38 (2010).

  54. 54.

    Poirel, L., Potron, A. & Nordmann, P. OXA-48-like carbapenemases: the phantom menace. J. Antimicrob. Chemother. 67, 1597–1606 (2012).

  55. 55.

    Evans, B. A. & Amyes, S. G. B. OXA β-lactamases. Clin. Microbiol. Rev. 27, 241–263 (2014).

  56. 56.

    Ehmann, D. E. et al. Kinetics of avibactam inhibition against Class A, C, and D β-lactamases. J. Biol. Chem. 288, 27960–27971 (2013).

  57. 57.

    Kazmierczak, K. M., Bradford, P. A., Stone, G. G., deJonge, B. L. M. & Sahm, D. F. In vitro activity of ceftazidime-avibactam and aztreonam-avibactam against OXA-48-carrying Enterobacteriaceae isolated as part of the International Network for Optimal Resistance Monitoring (INFORM) Global Surveillance Program from 2012 to 2015. Antimicrob. Agents Chemother. 62, e00592–18 (2018).

  58. 58.

    Poirel, L., Héritier, C., Tolün, V. & Nordmann, P. Emergence of oxacillinase-mediated resistance to imipenem in Klebsiella pneumoniae. Antimicrob. Agents Chemother. 48, 15–22 (2004).

  59. 59.

    Hakenbeck, R. & Coyette, J. Resistant penicillin-binding proteins. Cell. Mol. Life Sci. 54, 332–340 (1998).

  60. 60.

    Neu, H. C. β-Lactamases β-lactamase inhibitors, and skin and skin-structure infections. J. Am. Acad. Dermatol. 22, 896–904 (1990).

  61. 61.

    Prabaker, K. & Weinstein, R. A. Trends in antimicrobial resistance in intensive care units in the United States. Curr. Opin. Crit. Care 17, 472–479 (2011).

  62. 62.

    Harris, P., Paterson, D. & Rogers, B. Facing the challenge of multidrug-resistant gram-negative bacilli in Australia. Med. J. Aust. 202, 243–247 (2015).

  63. 63.

    Eisenstein, B. I., Sox, T., Biswas, G., Blackman, E. & Sparling, P. F. Conjugal transfer of the gonococcal penicillinase plasmid. Science 195, 998–1000 (1977).

  64. 64.

    Medeiros, A. A. & O’Brien, T. F. Ampicillin-resistant Haemophilus influenzae type B possessing a TEM-type β-lactamase but little permeability barrier to ampicillin. Lancet 1, 716–719 (1975).

  65. 65.

    Fisher, J., Charnas, R. L. & Knowles, J. R. Kinetic studies on the inactivation of Escherichia coli RTEM β-lactamase by clavulanic acid. Biochemistry 17, 2180–2184 (1978).This paper presents the first evidence showing that clavulanic acid functions as an irreversible suicide inactivator of the TEM β-lactamase.

  66. 66.

    Charnas, R. L., Fisher, J. & Knowles, J. R. Chemical studies on the inactivation of Escherichia coli RTEM β-lactamase by clavulanic acid. Biochemistry 17, 2185–2189 (1978).

  67. 67.

    Fisher, J., Charnas, R. L., Bradley, S. M. & Knowles, J. R. Inactivation of the RTEM β-lactamase from Escherichia coli. Interaction of penam sulfones with enzyme. Biochemistry 20, 2726–2731 (1981).

  68. 68.

    Bush, K., Macalintal, C., Rasmussen, B. A., Lee, V. J. & Yang, Y. Kinetic interactions of tazobactam with β-lactamases from all major structural classes. Antimicrob. Agents Chemother. 37, 851–858 (1993).

  69. 69.

    English, A. R., Retsema, J. A., Girard, A. E., Lynch, J. E. & Barth, W. E. CP-45,899, a beta-lactamase inhibitor that extends the antibacterial spectrum of beta-lactams: initial bacteriological characterization. Antimicrob. Agents Chemother. 14, 414–419 (1978).

  70. 70.

    Drawz, S. M. & Bonomo, R. A. Three decades of β-lactamase inhibitors. Clin. Microbiol. Rev. 23, 160–201 (2010).

  71. 71.

    Kitzis, M. D., Goldstein, F. W., Labia, R. & Acar, J. F. Activity of sulbactam and clavulanic acid, alone and combined, on Acinetobacter calcoaceticus [French]. Ann. Microbiol. 134a, 163–168 (1983).

  72. 72.

    Aronoff, S. C., Jacobs, M. R., Johenning, S. & Yamabe, S. Comparative activities of the β-lactamase inhibitors YTR 830, sodium clavulanate, and sulbactam combined with amoxicillin or ampicillin. Antimicrob. Agents Chemother. 26, 580–582 (1984).

  73. 73.

    Payne, D. J., Cramp, R., Winstanley, D. J. & Knowles, D. J. Comparative activities of clavulanic acid, sulbactam, and tazobactam against clinically important β-lactamases. Antimicrob. Agents Chemother. 38, 767–772 (1994).This article presents a comparison of the inhibitory potency of the first three commercially available BLIs against serine β-lactamases.

  74. 74.

    Grace, M. E., Fu, K. P., Gregory, F. J. & Hung, P. P. Interaction of clavulanic acid, sulbactam and cephamycin antibiotics with beta-lactamases. Drugs Exp. Clin. Res. 13, 145–148 (1987).

  75. 75.

    Shapiro, A. B. Kinetics of sulbactam hydrolysis by β-lactamases, and kinetics of β-lactamase inhibition by sulbactam. Antimicrob. Agents Chemother. 61, e01612–17 (2017).

  76. 76.

    Kuzin, A. P. et al. Inhibition of the SHV-1 β-lactamase by sulfones: crystallographic observation of two reaction intermediates with tazobactam. Biochemistry 40, 1861–1866 (2001).

  77. 77.

    Charbonneau, P. Review of piperacillin/tazobactam in the treatment of bacteremic infections and summary of clinical efficacy. Intensive Care Med. 20, (Suppl. 3), S43–S48 (1994).

  78. 78.

    Newton, L., Kotowski, A., Grinker, M. & Chun, R. Diagnosis and management of pediatric sinusitis: a survey of primary care, otolaryngology and urgent care providers. Int. J. Pediatr. Otorhinolaryngol 108, 163–167 (2018).

  79. 79.

    Horita, N., Shibata, Y., Watanabe, H., Namkoong, H. & Kaneko, T. Comparison of antipseudomonal β-lactams for febrile neutropenia empiric therapy: systematic review and network meta-analysis. Clin. Microbiol. Infect. 23, 723–729 (2017).

  80. 80.

    Nimmich, E. B. et al. Development of institutional guidelines for management of Gram-negative bloodstream infections: incorporating local evidence. Hosp. Pharm. 52, 691–697 (2017).

  81. 81.

    Zhanel, G. G. et al. Ceftolozane/tazobactam: a novel cephalosporin/beta-lactamase inhibitor combination with activity against multidrug-resistant gram-negative bacilli. Drugs 74, 31–51 (2014).

  82. 82.

    Livermore, D. M., Mushtaq, S., Warner, M., Turner, S. J. & Woodford, N. Potential of high-dose cefepime/tazobactam against multiresistant Gram-negative pathogens. J. Antimicrob. Chemother. 73, 126–133 (2018).

  83. 83.

    Schechter, L. M. et al. Extensive gene amplification as a mechanism for piperacillin-tazobactam resistance in Escherichia coli. mBio 9, e00583–18 (2018).

  84. 84.

    Bush, K. β-Lactamase inhibitors from laboratory to clinic. Clin. Microbiol. Rev. 1, 109–123 (1988).

  85. 85.

    Pilmis, B., Jullien, V., Tabah, A., Zahar, J. R. & Brun-Buisson, C. Piperacillin-tazobactam as alternative to carbapenems for ICU patients. Ann. Intensive Care 7, 113 (2017).

  86. 86.

    Drawz, S. M., Papp-Wallace, K. M. & Bonomo, R. A. New β-lactamase inhibitors: a therapeutic renaissance in an MDR world. Antimicrob. Agents Chemother. 58, 1835–1846 (2014).This paper provides an excellent review of newer BLIs and covers structural, mechanistic and clinical aspects.

  87. 87.

    Papp-Wallace, K. M. et al. Inhibitor resistance in the KPC-2 β-lactamase, a preeminent property of this class A β-lactamase. Antimicrob. Agents Chemother. 54, 890–897 (2010).

  88. 88.

    Coleman, K. Diazabicyclooctanes (DBOs): a potent new class of non-β-lactam β-lactamase inhibitors. Curr. Opin. Microbiol. 14, 550–555 (2011).

  89. 89.

    Livermore, D. M. et al. Activities of NXL104 combinations with ceftazidime and aztreonam against carbapenemase-producing Enterobacteriaceae. Antimicrob. Agents Chemother. 55, 390–394 (2011).

  90. 90.

    Ehmann, D. E. et al. Avibactam is a covalent, reversible, non-β-lactam β-lactamase inhibitor. Proc. Natl Acad. Sci. USA 109, 11663–11668 (2012).This article presents the first evidence that avibactam is a reversible BLI, in contrast to the earlier suicide inhibitors.

  91. 91.

    Citron, D. M., Tyrrell, K. L., Merriam, V. & Goldstein, E. J. In vitro activity of ceftazidime-NXL104 against 396 strains of β-lactamase-producing anaerobes. Antimicrob. Agents Chemother. 55, 3616–3620 (2011).

  92. 92.

    Nichols, W. W., Newell, P., Critchley, I. A., Riccobene, T. & Das, S. Avibactam pharmacokinetic/pharmacodynamic targets. Antimicrob. Agents Chemother. 62, e02446–17 (2018).This paper provides an in-depth investigation of the PK/PD of the BLI avibactam.

  93. 93.

    Wagenlehner, F. M. et al. Ceftazidime-avibactam versus doripenem for the treatment of complicated urinary tract infections, including acute pyelonephritis: RECAPTURE, a Phase 3 randomized trial program. Clin. Infect. Dis. 63, 754–762 (2016).

  94. 94.

    Mazuski, J. E. et al. Efficacy and safety of ceftazidime-avibactam plus metronidazole versus meropenem in the treatment of complicated intra-abdominal infection: results from a randomized, controlled, double-blind, phase 3 program. Clin. Infect. Dis. 62, 1380–1389 (2016).

  95. 95.

    Biedenbach, D. J., Kazmierczak, K., Bouchillon, S. K., Sahm, D. F. & Bradford, P. A. In vitro activity of aztreonam-avibactam against a global collection of Gram-negative pathogens from 2012 and 2013. Antimicrob. Agents Chemother. 59, 4239–4248 (2015).

  96. 96.

    US National Library of Medicine. (2019).

  97. 97.

    Livermore, D. M., Warner, M. & Mushtaq, S. Activity of MK-7655 combined with imipenem against Enterobacteriaceae and Pseudomonas aeruginosa. J. Antimicrob. Chemothery 68, 2286–2290 (2013).

  98. 98.

    Lapuebla, A. et al. Activity of imipenem with relebactam against Gram-negative pathogens from New York City. Antimicrob. Agents Chemother. 59, 5029–5031 (2015).

  99. 99.

    Hirsch, E. B. et al. In vitro activity of MK-7655, a novel β-lactamase inhibitor, in combination with imipenem against carbapenem-resistant Gram-negative bacteria. Antimicrob. Agents Chemother. 56, 3753–3757 (2012).

  100. 100.

    US National Library of Medicine. (2017).

  101. 101.

    US National Library of Medicine. (2016).

  102. 102.

    US National Library of Medicine. (2018).

  103. 103.

    Morinaka, A. et al. OP0595, a new diazabicyclooctane: mode of action as a serine β-lactamase inhibitor, antibiotic and β-lactam ‘enhancer’. J. Antimicrob. Chemother. 70, 2779–2786 (2015).

  104. 104.

    Livermore, D. M., Warner, M., Mushtaq, S. & Woodford, N. Interactions of OP0595, a novel triple-action diazabicyclooctane, with β-lactams against OP0595-resistant Enterobacteriaceae mutants. Antimicrob. Agents Chemother. 60, 554–560 (2016).

  105. 105.

    Doumith, M., Mushtaq, S., Livermore, D. M. & Woodford, N. New insights into the regulatory pathways associated with the activation of the stringent response in bacterial resistance to the PBP2-targeted antibiotics, mecillinam and OP0595/RG6080. J. Antimicrob. Chemother. 71, 2810–2814 (2016).

  106. 106.

    Tyrrell, J. M. et al. Nacubactam antibacterial activity alone and in combination with beta-lactam antibiotics against contemporary Enterobacteriaceae clinical isolates [abstract P1034]. Presented at the 28th European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) in Madrid, Spain (2018).

  107. 107.

    Monogue, M., Giovagnoli, S., Bissantz, C., Zampaloni, C. & Nicolau, D. In vivo efficacy of meropenem with a novel non-beta-lactam–beta-lactamase inhibitor, nacubactam, against Gram-negative organisms exhibiting various resistance mechanisms in a murine complicated urinary tract infection model. Antimicrob. Agents Chemother. 62, e02596-17 (2018).

  108. 108.

    Louie, A. et al. Pharmacokinetic (PK) and pharmacodynamic (PD) of nacubactam (RG6080, OP0595) in combination with meropenem in neutropenic mice thigh infection model [abstract P2422]. Presented at the 28th European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) in Madrid, Spain (2018).

  109. 109.

    US National Library of Medicine. (2018).

  110. 110.

    Livermore, D. M., Mushtaq, S., Warner, M., Vickers, A. & Woodford, N. In vitro activity of cefepime/zidebactam (WCK 5222) against Gram-negative bacteria. J. Antimicrob. Chemother. 72, 1373–1385 (2017).

  111. 111.

    US National Library of Medicine. (2016).

  112. 112.

    Shapiro, A. B. et al. Reversibility of covalent, broad-spectrum serine β-lactamase inhibition by the diazabicyclooctenone ETX2514. ACS Infect. Dis. 3, 833–844 (2017).

  113. 113.

    Durand-Réville, T. F. et al. ETX2514 is a broad-spectrum β-lactamase inhibitor for the treatment of drug-resistant Gram-negative bacteria including Acinetobacter baumannii. Nat. Microbiol. 2, 17104 (2017).

  114. 114.

    Higgins, P. G., Wisplinghoff, H., Stefanik, D. & Seifert, H. In vitro activities of the β-lactamase inhibitors clavulanic acid, sulbactam, and tazobactam alone or in combination with β-lactams against epidemiologically characterized multidrug-resistant Acinetobacter baumannii strains. Antimicrob. Agents Chemother. 48, 1586–1592 (2004).

  115. 115.

    US National Library of Medicine. (2019).

  116. 116.

    Philipp, M. & Bender, M. L. Inhibition of serine proteases by arylboronic acids. Proc. Natl Acad. Sci. USA 68, 478–480 (1971).

  117. 117.

    Hecker, S. J. et al. Discovery of a cyclic boronic acid β-lactamase inhibitor (RPX7009) with utility versus class A serine carbapenemases. J. Med. Chem. 58, 3682–3692 (2015).

  118. 118.

    Castanheira, M., Rhomberg, P. R., Flamm, R. K. & Jones, R. N. Effect of the β-lactamase inhibitor vaborbactam combined with meropenem against serine carbapenemase-producing Enterobacteriaceae. Antimicrob. Agents Chemother. 60, 5454–5458 (2016).

  119. 119.

    Kaye, K. S. et al. Effect of meropenem-vaborbactam versus piperacillin-tazobactam on clinical cure or improvement and microbial eradication in complicated urinary tract infection: the TANGO I randomized clinical trial. JAMA 319, 788–799 (2018).

  120. 120.

    US Food & Drug Administration. Highlights of prescribing information. Vabomere™ (meropenem and vaborbactam) for injection, for intravenous use. (2018).

  121. 121.

    Mushtaq, S., Vickers, A., Woodford, N. & Livermore, D. M. Potentiation of cefepime by the boronate VNRX-5133 versus gram-negative bacteria with known β-lactamases [abstract P1536]. Presented at the 28th European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) in Madrid, Spain (2018).

  122. 122.

    Docquier, J.-D. et al. Structural basis for serine- and metallo-β-lactamase inhibition by VNRX-5133, a new β-lactamase inhibitor (BLI) in clinical development [abstact O0603]. Presented at the 28th European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) in Madrid, Spain (2018).

  123. 123.

    Donnelly, R. et al. In vitro activity of cefepime alone and in combination with the broad-spectrum β-lactamase inhibitor VNRX-5133 against ESBL and carbapenamases harbouring Enterobacteriaceae and Pseudomonas spp [abstract P1539]. Presented at the 28th European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) in Madrid, Spain (2018).

  124. 124.

    Weiss, W. J. et al. Efficacy of cefepime / VNRX-5133, a novel β-lactamase inhibitor, against cephalosporin resistant, ESBL-producing K. pneumoniae in a murine lung-infection model [abstract O0600]. Presented at the 28th European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) in Madrid, Spain (2018).

  125. 125.

    Georgiou, P.-C. et al. Pharmacodynamics of the novel broad-spectrum β-lactamase inhibitor VNRX-5133 in combination with cefepime in neutropenic female CD-1 mice with experimental pneumonia [abstract O0575]. Presented at the 28th European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) in Madrid, Spain (2018).

  126. 126.

    Georgiou, P. C. et al. VNRX-5133, a novel broad-spectrum β-lactamase inhibitor, enhances the activity of cefepime against Enterobacteriaceae and P. aeruginosa isolates in a neutropenic mouse-thigh infection model [abstract P1540]. Presented at the 28th European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) in Madrid, Spain (2018).

  127. 127.

    US National Library of Medicine. (2017).

  128. 128.

    Papp-Wallace, K. M. et al. AAI101, a novel β-lactamase inhibitor: microbiological and enzymatic profiling. Open Forum Infect. Dis. 4, S375 (2017).

  129. 129.

    Huband, M. D. et al. In vitro activity of a novel extended-spectrum β-lactamase inhibitor, AAI101, in combination with cefepime against Enterobacteriaceae isolates collected during 2016 [abstract Friday-601]. Presented at the 2018 American Society for Microbiology (ASM) Microbe conference in Atlanta, GA, USA (2018).

  130. 130.

    Crandon, J. L. & Nicolau, D. P. In vivo activities of simulated human doses of cefepime and cefepime-AAI101 against multidrug-resistant Gram-negative Enterobacteriaceae. Antimicrob. Agents Chemother. 59, 2688–2694 (2015).

  131. 131.

    US National Library of Medicine. (2018).

  132. 132.

    Everett, M. et al. Discovery of a novel metallo-β-lactamase inhibitor that potentiates meropenem activity against carbapenem-resistant Enterobacteriaceae. Antimicrob. Agents Chemother. 62, e00074–18 (2018).

  133. 133.

    Livermore, D. M. et al. In vitro selection of ceftazidime-avibactam resistance in Enterobacteriaceae with KPC-3 carbapenemase. Antimicrob. Agents Chemother. 59, 5324–5330 (2015).

  134. 134.

    Shields, R. K. et al. Emergence of ceftazidime-avibactam resistance due to plasmid-borne bla KPC-3 mutations during treatment of carbapenem-resistant Klebsiella pneumoniae infections. Antimicrob. Agents Chemother. 61, e02097–16 (2017).

  135. 135.

    Alm, R. A., Johnstone, M. R. & Lahiri, S. D. Characterization of Escherichia coli NDM isolates with decreased susceptibility to aztreonam/avibactam: role of a novel insertion in PBP3. J. Antimicrob. Chemother. 70, 1420–1428 (2015).

  136. 136.

    Zhang, Y., Kashikar, A., Brown, C. A., Denys, G. & Bush, K. Unusual Escherichia coli PBP 3 insertion sequence identified from a collection of carbapenem-resistant Enterobacteriaceae tested in vitro with a combination of ceftazidime-, ceftaroline-, or aztreonam-avibactam. Antimicrob. Agents Chemother. 61, e00389–17 (2017).

  137. 137.

    Sun, D., Rubio-Aparicio, D., Nelson, K., Dudley, M. N. & Lomovskaya, O. Meropenem-vaborbactam resistance selection, resistance prevention, and molecular mechanisms in mutants of KPC-producing Klebsiella pneumoniae. Antimicrob. Agents Chemother. 61, e01694–17 (2017).

  138. 138.

    van Duin, D. et al. Colistin versus ceftazidime-avibactam in the treatment of infections due to carbapenem-resistant Enterobacteriaceae. Clin. Infect. Dis 66, 163–171 (2018).

  139. 139.

    Jaurin, B. & Grundstrom, T. ampC cephalosporinase of Escherichia coli K-12 has a different evolutionary origin from that of β-lactamases of the penicillinase type. Proc. Natl Acad. Sci. USA 78, 4897–4901 (1981).

  140. 140.

    Huovinen, P., Huovinen, S. & Jacoby, G. A. Sequence of PSE-2 β-lactamase. Antimicrob. Agents Chemother. 32, 134–136 (1988).

Download references

Reviewer information

Nature Reviews Microbiology thanks R. A. Bonomo, D. Shlaes and the other anonymous reviewer(s) for their contribution to the peer review of this work.

Author information

K.B. and P.A.B. researched data for the article, made substantial contributions to discussions of the content, wrote the article and reviewed and/or edited the manuscript before submission.

Competing interests

The authors declare competing interests. K.B. serves as an independent consultant for pharmaceutical and biotechnology companies that discover and develop antimicrobial agents. P.A.B. is an independent consultant for companies that work on antibacterial agents. No support or input for the manuscript was provided by any of the companies for which K.B. or P.A.B. consult.

Correspondence to Karen Bush or Patricia A. Bradford.


Penicillin-binding proteins

(PBPs). Bacterial cell wall synthesizing enzymes that are the killing targets of β-lactam antibiotics.


Bacterial enzymes that hydrolyse β-lactam bonds in β-lactam-containing antibiotics.


Genetic elements, often including resistance determinants, that can be inserted into or excised from bacterial DNA.

Porin proteins

Bacterial proteins that form channels through the outer membrane of Gram-negative bacteria to allow the entry and exit of small molecules from the periplasmic space of the cell.

Hollow fibre model

An in vitro pharmacodynamics model that allows bacteria inside a porous membrane to be exposed to varying drug concentrations in a dynamic system that can be programmed to mimic human dosing regimens.

Stringent response

Refers to the reaction of a bacterial cell to environmental stress.

Rights and permissions

To obtain permission to re-use content from this article visit RightsLink.

About this article

Publication history

  • Published

  • Issue Date


Fig. 1: Structures of β-lactams and β-lactamase inhibitors.
Fig. 2: General reaction pathway for the interaction of a β-lactam with penicillin-interactive enzymes.
Fig. 3: General mechanism of hydrolysis of β-lactams for serine and metallo-β-lactamases.
Fig. 4: General reaction mechanism for inhibition of a β-lactamase by a mechanism-based β-lactamase inhibitor.