{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T00:52:24Z","timestamp":1760057544502,"version":"build-2065373602"},"reference-count":44,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2025,2,14]],"date-time":"2025-02-14T00:00:00Z","timestamp":1739491200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"FCT-Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["SFRH\/BD\/04631\/2021","SFRH\/BPD\/123504\/2016","UIDB\/00329\/2020","UID\/00329\/2025","LA\/P\/0121\/2020"],"award-info":[{"award-number":["SFRH\/BD\/04631\/2021","SFRH\/BPD\/123504\/2016","UIDB\/00329\/2020","UID\/00329\/2025","LA\/P\/0121\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Antibiotics"],"abstract":"<jats:p>Objectives: Antibiotic-resistant bacteria are widespread, with resistance arising from chromosomal mutations and resistance genes located in the chromosome or in mobile genetic elements. While resistance determinants often reduce bacterial growth rates, their influence on bacterial death under bactericidal antibiotics remains poorly understood. When bacteria are exposed to bactericidal antibiotics to which they are susceptible, they typically undergo a two-phase decline: a fast initial exponentially decaying phase, followed by a persistent slow-decaying phase. This study examined how resistance determinants affect death rates during both phases. Methods: We analyzed the death rates of ampicillin-exposed Escherichia coli populations of strains sensitive to ampicillin but resistant to nalidixic acid, rifampicin, or both, and bacteria carrying the conjugative plasmids RN3 or R702. Results: Single mutants resistant to nalidixic acid or rifampicin decayed faster than sensitive cells during the early phase, whereas the double-resistant mutant exhibited prolonged survival. These contrasting impacts suggest epistatic interactions between both chromosomal mutations. Persistent-phase death rates for chromosomal mutants did not differ significantly from wild-type cells. In contrast, plasmid-carrying bacteria displayed distinct dynamics: R702 plasmid-bearing cells showed higher persistent-phase death rates than plasmid-free cells, while RN3 plasmid-bearing cells exhibited lower rates. Conclusions: Bactericidal antibiotics may kill bacteria resistant to other antibiotics more effectively than wild-type cells. Moreover, epistasis may occur when different resistance determinants occur in the same cell, impacting the bactericidal potential of the antibiotic of choice. These results have significant implications for optimizing bacterial eradication protocols in clinical settings, as well as in animal health and industrial food safety management.<\/jats:p>","DOI":"10.3390\/antibiotics14020201","type":"journal-article","created":{"date-parts":[[2025,2,14]],"date-time":"2025-02-14T11:14:41Z","timestamp":1739531681000},"page":"201","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["What Is the Impact of Antibiotic Resistance Determinants on the Bacterial Death Rate?"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0009-0004-5705-8366","authenticated-orcid":false,"given":"Bruno T. S.","family":"Luz","sequence":"first","affiliation":[{"name":"cE3c\u2014Centre for Ecology, Evolution and Environmental Changes & CHANGE, Global Change and Sustainability Institute, Faculdade de Ci\u00eancias, Universidade de Lisboa, 1749-016 Lisboa, Portugal"}]},{"given":"Jo\u00e3o S.","family":"Rebelo","sequence":"additional","affiliation":[{"name":"cE3c\u2014Centre for Ecology, Evolution and Environmental Changes & CHANGE, Global Change and Sustainability Institute, Faculdade de Ci\u00eancias, Universidade de Lisboa, 1749-016 Lisboa, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5275-714X","authenticated-orcid":false,"given":"Francisca","family":"Monteiro","sequence":"additional","affiliation":[{"name":"cE3c\u2014Centre for Ecology, Evolution and Environmental Changes & CHANGE, Global Change and Sustainability Institute, Faculdade de Ci\u00eancias, Universidade de Lisboa, 1749-016 Lisboa, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3653-1511","authenticated-orcid":false,"given":"Francisco","family":"Dionisio","sequence":"additional","affiliation":[{"name":"cE3c\u2014Centre for Ecology, Evolution and Environmental Changes & CHANGE, Global Change and Sustainability Institute, Faculdade de Ci\u00eancias, Universidade de Lisboa, 1749-016 Lisboa, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2025,2,14]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"418","DOI":"10.1038\/nature13469","article-title":"Optimization of Lag Time Underlies Antibiotic Tolerance in Evolved Bacterial Populations","volume":"513","author":"Fridman","year":"2014","journal-title":"Nature"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"295","DOI":"10.1038\/hdy.2017.33","article-title":"Social Behaviour Involving Drug Resistance: The Role of Initial Density, Initial Frequency and Population Structure in Shaping the Effect of Antibiotic Resistance as a Public Good","volume":"119","author":"Domingues","year":"2017","journal-title":"Heredity"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"100","DOI":"10.1093\/jac\/dkv312","article-title":"Indirect Resistance to Several Classes of Antibiotics in Cocultures with Resistant Bacteria Expressing Antibiotic-Modifying or -Degrading Enzymes","volume":"71","author":"Nicoloff","year":"2016","journal-title":"J. Antimicrob. Chemoth."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"441","DOI":"10.1038\/s41579-019-0196-3","article-title":"Definitions and Guidelines for Research on Antibiotic Persistence","volume":"17","author":"Balaban","year":"2019","journal-title":"Nat. Rev. Microbiol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1807","DOI":"10.1534\/genetics.104.035352","article-title":"Bacterial Persistence: A Model of Survival in Changing Environments","volume":"169","author":"Kussell","year":"2005","journal-title":"Genetics"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"174","DOI":"10.1038\/s41392-024-01866-5","article-title":"Bacterial Persisters: Molecular Mechanisms and Therapeutic Development","volume":"9","author":"Niu","year":"2024","journal-title":"Sig. Transduct. Target. Ther."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"357","DOI":"10.1146\/annurev.micro.112408.134306","article-title":"Persister Cells","volume":"64","author":"Lewis","year":"2010","journal-title":"Annu. Rev. Microbiol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"479","DOI":"10.1038\/s41579-020-0378-z","article-title":"Evolutionary Causes and Consequences of Bacterial Antibiotic Persistence","volume":"18","author":"Bakkeren","year":"2020","journal-title":"Nat. Rev. Microbiol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"556","DOI":"10.1038\/nrmicro1445","article-title":"Opinion\u2014Non-Inherited Antibiotic Resistance","volume":"4","author":"Levin","year":"2006","journal-title":"Nat. Rev. Microbiol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"e57309","DOI":"10.15252\/embr.202357309","article-title":"Environmental, Mechanistic and Evolutionary Landscape of Antibiotic Persistence","volume":"24","author":"Bollen","year":"2023","journal-title":"EMBO Rep."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"106310","DOI":"10.1016\/j.micpath.2023.106310","article-title":"(P)ppGpp Synthetase Rsh Participates in Rifampicin Tolerance of Persister Cells in Brucella Abortus in Vitro","volume":"183","author":"Liu","year":"2023","journal-title":"Microb. Pathog."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Liu, X., Wang, P., Yuan, N., Zhai, Y., Yang, Y., Hao, M., Zhang, M., Zhou, D., Liu, W., and Jin, Y. (2024). The (p)ppGpp Synthetase Rsh Promotes Rifampicin Tolerant Persister Cell Formation in Brucella Abortus by Regulating the Type II Toxin-Antitoxin Module mbcTA. Front. Microbiol., 15.","DOI":"10.3389\/fmicb.2024.1395504"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"116","DOI":"10.1016\/j.vetmic.2017.09.007","article-title":"The Role of ATP Pools in Persister Cell Formation in (Fluoro)Quinolone-Susceptible and -Resistant Strains of Salmonella Enterica Ser. Typhimurium","volume":"210","author":"Braetz","year":"2017","journal-title":"Vet. Microbiol."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Darmancier, H., Domingues, C.P.F., Rebelo, J.S., Amaro, A., Dion\u00edsio, F., Pothier, J., Serra, O., and Nogueira, T. (2022). Are Virulence and Antibiotic Resistance Genes Linked? A Comprehensive Analysis of Bacterial Chromosomes and Plasmids. Antibiotics, 11.","DOI":"10.3390\/antibiotics11060706"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Domingues, C.P.F., Rebelo, J.S., Dionisio, F., and Nogueira, T. (2023). Multi-Drug Resistance in Bacterial Genomes\u2014A Comprehensive Bioinformatic Analysis. Int. J. Mol. Sci., 24.","DOI":"10.3390\/ijms241411438"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Mancuso, G., Midiri, A., Gerace, E., and Biondo, C. (2021). Bacterial Antibiotic Resistance: The Most Critical Pathogens. Pathogens, 10.","DOI":"10.3390\/pathogens10101310"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"17635","DOI":"10.1073\/pnas.1903836116","article-title":"Power-Law Tail in Lag Time Distribution Underlies Bacterial Persistence","volume":"116","author":"Simsek","year":"2019","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1016\/j.mib.2014.06.016","article-title":"Persistence: A Copacetic and Parsimonious Hypothesis for the Existence of Non-Inherited Resistance to Antibiotics","volume":"21","author":"Levin","year":"2014","journal-title":"Curr. Opin. Microbiol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"2566","DOI":"10.1073\/pnas.012582999","article-title":"Random Graph Models of Social Networks","volume":"99","author":"Newman","year":"2002","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"323","DOI":"10.1080\/00107510500052444","article-title":"Power Laws, Pareto Distributions and Zipf\u2019s Law","volume":"46","author":"Newman","year":"2005","journal-title":"Contemp. Phys."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"033127","DOI":"10.1103\/PhysRevResearch.4.033127","article-title":"Slow Relaxation and Aging in the Model of Randomly Connected Cycles Network","volume":"4","author":"Reich","year":"2022","journal-title":"Phys. Rev. Res."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"290","DOI":"10.1038\/s41586-021-04114-w","article-title":"Observation of Universal Ageing Dynamics in Antibiotic Persistence","volume":"600","author":"Kaplan","year":"2021","journal-title":"Nature"},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Rebelo, J.S., Domingues, C.P.F., Monteiro, F., Nogueira, T., and Dionisio, F. (2021). Bacterial Persistence Is Essential for Susceptible Cell Survival in Indirect Resistance, Mainly for Lower Cell Densities. PLoS ONE, 16.","DOI":"10.1371\/journal.pone.0246500"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"3617","DOI":"10.1098\/rspb.2011.1537","article-title":"The Causes of Epistasis","volume":"278","author":"Cooper","year":"2011","journal-title":"Proc. R. Soc. B Biol. Sci."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"372","DOI":"10.1061\/(ASCE)0733-9372(2009)135:5(372)","article-title":"Biphasic Decay Kinetics of Fecal Bacteria in Surface Water Not a Density Effect","volume":"135","author":"Hellweger","year":"2009","journal-title":"J. Environ. Eng."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1622","DOI":"10.1126\/science.1099390","article-title":"Bacterial Persistence as a Phenotypic Switch","volume":"305","author":"Balaban","year":"2004","journal-title":"Science"},{"key":"ref_27","first-page":"277","article-title":"The Antibiotic Resistance Crisis","volume":"40","author":"Ventola","year":"2015","journal-title":"Pharm. Ther."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1944","DOI":"10.1126\/science.1124410","article-title":"The Competitive Cost of Antibiotic Resistance in Mycobacterium Tuberculosis","volume":"312","author":"Gagneux","year":"2006","journal-title":"Science"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1471","DOI":"10.1093\/genetics\/156.4.1471","article-title":"Compensatory Evolution in Rifampin-Resistant Escherichia Coli","volume":"156","author":"Reynolds","year":"2000","journal-title":"Genetics"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"179","DOI":"10.1128\/JCM.00750-06","article-title":"Detection of Multidrug Resistance in Mycobacterium Tuberculosis","volume":"45","author":"Sekiguchi","year":"2007","journal-title":"J. Clin. Microbiol."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Trindade, S., Sousa, A., Xavier, K.B., Dionisio, F., Ferreira, M.G., and Gordo, I. (2009). Positive Epistasis Drives the Acquisition of Multidrug Resistance. PLoS Genet., 5.","DOI":"10.1371\/journal.pgen.1000578"},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Silva, R.F., Mendon\u00e7a, S.C., Carvalho, L.M., Reis, A.M., Gordo, I., Trindade, S., and Dionisio, F. (2011). Pervasive Sign Epistasis between Conjugative Plasmids and Drug-Resistance Chromosomal Mutations. PLoS Genet., 7.","DOI":"10.1371\/journal.pgen.1002181"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"601","DOI":"10.1038\/ismej.2013.182","article-title":"Positive Epistasis between Co-Infecting Plasmids Promotes Plasmid Survival in Bacterial Populations","volume":"8","author":"Heilbron","year":"2014","journal-title":"ISME J."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"423","DOI":"10.1038\/nrmicro2333","article-title":"How Antibiotics Kill Bacteria: From Targets to Networks","volume":"8","author":"Kohanski","year":"2010","journal-title":"Nat. Rev. Microbiol."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Stojowska-Sw\u0119drzy\u0144ska, K., Kuczy\u0144ska-Wi\u015bnik, D., and Laskowska, E. (2023). New Strategies to Kill Metabolically-Dormant Cells Directly Bypassing the Need for Active Cellular Processes. Antibiotics, 12.","DOI":"10.3390\/antibiotics12061044"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1629","DOI":"10.1126\/science.1101630","article-title":"SOS Response Induction by SS-Lactams and Bacterial Defense Against Antibiotic Lethality","volume":"305","author":"Miller","year":"2004","journal-title":"Science"},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Dorr, T., Lewis, K., and Vulic, M. (2009). SOS Response Induces Persistence to Fluoroquinolones in Escherichia Coli. PLoS Genet., 5.","DOI":"10.1371\/journal.pgen.1000760"},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Podlesek, Z., and \u017dgur Bertok, D. (2020). The DNA Damage Inducible SOS Response Is a Key Player in the Generation of Bacterial Persister Cells and Population Wide Tolerance. Front. Microbiol., 11.","DOI":"10.3389\/fmicb.2020.01785"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"521","DOI":"10.1016\/j.tig.2017.05.003","article-title":"Antibiotic-Independent Adaptive Effects of Antibiotic Resistance Mutations","volume":"33","author":"Hershberg","year":"2017","journal-title":"Trends Genet."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"e01495-17","DOI":"10.1128\/AAC.01495-17","article-title":"Evolution of Antibiotic Resistance without Antibiotic Exposure","volume":"61","author":"Andersson","year":"2017","journal-title":"Antimicrob. Agents Chemother."},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Rodr\u00edguez-Verdugo, A., Gaut, B.S., and Tenaillon, O. (2013). Evolution of Escherichia Coli Rifampicin Resistance in an Antibiotic-Free Environment during Thermal Stress. BMC Evol. Biol., 13.","DOI":"10.1186\/1471-2148-13-50"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"539","DOI":"10.1534\/genetics.109.106104","article-title":"The Fitness Cost of Streptomycin Resistance Depends on rpsL Mutation, Carbon Source and RpoS (\u03c3S)","volume":"183","author":"Paulander","year":"2009","journal-title":"Genetics"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"1743","DOI":"10.1093\/gbe\/evv102","article-title":"Alarmingly High Segregation Frequencies of Quinolone Resistance Alleles within Human and Animal Microbiomes Are Not Explained by Direct Clinical Antibiotic Exposure","volume":"7","author":"Field","year":"2015","journal-title":"Genome Biol. Evol."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"1758","DOI":"10.1093\/molbev\/msx118","article-title":"Rapid Genetic Adaptation during the First Four Months of Survival under Resource Exhaustion","volume":"34","author":"Avrani","year":"2017","journal-title":"Mol. Biol. Evol."}],"container-title":["Antibiotics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2079-6382\/14\/2\/201\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T16:34:36Z","timestamp":1760027676000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2079-6382\/14\/2\/201"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,2,14]]},"references-count":44,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2025,2]]}},"alternative-id":["antibiotics14020201"],"URL":"https:\/\/doi.org\/10.3390\/antibiotics14020201","relation":{},"ISSN":["2079-6382"],"issn-type":[{"type":"electronic","value":"2079-6382"}],"subject":[],"published":{"date-parts":[[2025,2,14]]}}}