Subinhibitory concentrations of ciprofloxacin did not inhibit the formation of biofilm.
Dorota Wojnicz, Dorota Tichaczek-Goska, Marta Kicia 2015, 'Pentacyclic triterpenes combined with ciprofloxacin help to eradicate the biofilmformed in vitro by Escherichia coli', Indian Journal of Medical Researchhttp://www.ijmr.org.in/article.asp?issn=0971-5916;year=2015;volume=141;issue=3;spage=343;epage=353;aulast=Wojnicz. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
Yet subinhibitory stress levels may induce a substantial death rate.
Antoine Frenoy, Sebastian Bonhoeffer 2018, 'Death and population dynamics affect mutation rate estimates and evolvability understress in bacteria.', PLoS Biologyhttp://europepmc.org/articles/PMC5966242?pdf=render. Retrieved from PLOS CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
At higher, but still subinhibitory concentrations, resveratrol reduced antimicrobial lethality by more than 3 orders of magnitude.
Yuanli Liu, Jinan Zhou, Yilin Qu, Xinguang Yang, Guojing Shi, Xiuhong Wang, YuzhiHong, Karl Drlica, Xilin Zhao 2016, 'Resveratrol Antagonizes Antimicrobial Lethality and Stimulates Recovery of BacterialMutants.', PLoS ONEhttp://europepmc.org/articles/PMC4821490?pdf=render. Retrieved from PLOS CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
Furthermore, the frequency of the resistant subpopulation was not increased by preincubation with subinhibitory concentrationsof tobramycin.
Sarah E. Anderson, Edgar X. Sherman, David S. Weiss, Philip N. Rather 2018, 'Aminoglycoside Heteroresistance in Acinetobacter baumannii AB5075', mSpherehttps://doi.org/10.1128/mSphere.00271-18. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
At high concentrations, antibiotics exhibit antimicrobial activities on susceptible cells, while subinhibitory concentrations induce diverse biological responses in bacteria.
Steve P Bernier, Michael G Surette 2013, 'Concentration-dependent activity of antibiotics in natural environments', Frontiers in Microbiologyhttp://journal.frontiersin.org/Journal/10.3389/fmicb.2013.00020/full. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
The microdilution assay was performed to verify the interactions between the natural products and the antibiotics using a subinhibitory concentration.
Fernando G. Figueredo, Emerson O. Ferreira, Bruno F. F. Lucena, Cícero M. G. Torres,Daniel L. Lucetti, Elaine C. P. Lucetti, João Marcos F. L. Silva, Francisco A. V.Santos, Cássio R. Medeiros, Gardênia M. M. Oliveira, Aracélio V. Colares, José G.M. Costa, Henrique D. M. Coutinho, Irwin R. A. Menezes, Júlio C. F. Silva, Marta R.Kerntopf, Patrícia R. L. Figueiredo, Edinardo F. F. Matias 2013, 'Modulation of the Antibiotic Activity by Extracts from Amburana cearensis A. C. Smithand Anadenanthera macrocarpa (Benth.) Brenan', BioMed Research Internationalhttp://dx.doi.org/10.1155/2013/640682. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
The ergosterol assay showed that subinhibitory concentrations of the substances were able to reducethe amount of sterol extracted.
Nathalia N. R. Cardoso, Celuta S. Alviano, Arie F. Blank, Maria Teresa V. Romanos,Beatriz B. Fonseca, Sonia Rozental, Igor A. Rodrigues, Daniela S. Alviano 2016, 'Synergism Effect of the Essential Oil from Ocimum basilicum var. Maria Bonita andIts Major Components with Fluconazole and Its Influence on Ergosterol Biosynthesis',Evidence-Based Complementary and Alternative Medicinehttp://dx.doi.org/10.1155/2016/5647182. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)