Detection of respiration changes inside biofilms with microelectrodes during exposure to antibiotics

Lin, Jun; Wang, Zechen; Zang, Yue; Zhang, Dong; Qing, Xin

doi:10.1080/10934529.2018.1544782

Cited by 6 publications

(4 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A possible explanation for this observation is that antibiotic-damaged cells may continue to exhibit anabolic activity for some time, even as long as 24 h, although they are incapable of forming a visible colony on an agar plate. Other researchers have reported continued bacterial respiration following aggressive antimicrobial treatment (103)(104)(105)(106)(107)(108).…”

Section: Discussionmentioning

confidence: 97%

Conceptual Model of Biofilm Antibiotic Tolerance That Integrates Phenomena of Diffusion, Metabolism, Gene Expression, and Physiology

et al. 2019

View full text Add to dashboard Cite

Transcriptomic, metabolomic, physiological, and computational modeling approaches were integrated to gain insight into the mechanisms of antibiotic tolerance in an in vitro biofilm system. Pseudomonas aeruginosa biofilms were grown in drip flow reactors on a medium composed to mimic the exudate from a chronic wound. After 4 days, the biofilm was 114 μm thick with 9.45 log10 CFU cm−2. These biofilms exhibited tolerance, relative to exponential-phase planktonic cells, to subsequent treatment with ciprofloxacin. The specific growth rate of the biofilm was estimated via elemental balances to be approximately 0.37 h−1 and with a reaction-diffusion model to be 0.32 h−1, or one-third of the maximum specific growth rate for planktonic cells. Global analysis of gene expression indicated lower transcription of ribosomal genes and genes for other anabolic functions in biofilms than in exponential-phase planktonic cells and revealed the induction of multiple stress responses in biofilm cells, including those associated with growth arrest, zinc limitation, hypoxia, and acyl-homoserine lactone quorum sensing. Metabolic pathways for phenazine biosynthesis and denitrification were transcriptionally activated in biofilms. A customized reaction-diffusion model predicted that steep oxygen concentration gradients will form when these biofilms are thicker than about 40 μm. Mutant strains that were deficient in Psl polysaccharide synthesis, the stringent response, the stationary-phase response, and the membrane stress response exhibited increased ciprofloxacin susceptibility when cultured in biofilms. These results support a sequence of phenomena leading to biofilm antibiotic tolerance, involving oxygen limitation, electron acceptor starvation and growth arrest, induction of associated stress responses, and differentiation into protected cell states. IMPORTANCE Bacteria in biofilms are protected from killing by antibiotics, and this reduced susceptibility contributes to the persistence of infections such as those in the cystic fibrosis lung and chronic wounds. A generalized conceptual model of biofilm antimicrobial tolerance with the following mechanistic steps is proposed: (i) establishment of concentration gradients in metabolic substrates and products; (ii) active biological responses to these changes in the local chemical microenvironment; (iii) entry of biofilm cells into a spectrum of states involving alternative metabolisms, stress responses, slow growth, cessation of growth, or dormancy (all prior to antibiotic treatment); (iv) adaptive responses to antibiotic exposure; and (v) reduced susceptibility of microbial cells to antimicrobial challenges in some of the physiological states accessed through these changes.

show abstract

Section: Discussionmentioning

confidence: 97%

Conceptual Model of Biofilm Antibiotic Tolerance That Integrates Phenomena of Diffusion, Metabolism, Gene Expression, and Physiology

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Based on plate counting results, there was a significant decline in living cells after the introduction of antibiotics into the solution. Within 4 h of adding the antibiotic, the number of living cells decreased to less than 50% and dropped below 10% after 12 h. Evidently, ceftriaxone sodium is highly effective against planktonic cells . However, this effect was not detected by the blocking system.…”

Section: Resultsmentioning

confidence: 96%

Label-Free Detection of Single Living Bacteria: Single-Entity Electrochemistry Targeting Metabolic Products

Wang,

Lin,

et al. 2023

Anal. Chem.

Self Cite

View full text Add to dashboard Cite

This study presents a novel approach employing single-entity electrochemistry for the label-free detection of living Escherichia coli. By examination of the collision signals generated from the reduction of hydrogen peroxide, a metabolic product of E. coli that accumulates on the cell surface, the concentration of living bacteria can be determined. Within a broad concentration range from 3.0 × 107 to 1.0 × 109 cells/mL, cell aggregation was not observed. Cell migration in the solution was primarily governed by diffusion, exhibiting a diffusion coefficient of 6.8 × 10–9 cm2/s. The collision frequency exhibits a linear relationship with the cell concentration, aligning well with theoretical predictions. Through statistical analysis of each collision signal’s integrated charge quantity, the metabolic activity of single cells can be assessed. This method was applied to a cytotoxicity assay, where it monitored the decline in living cell numbers and metabolic activities in addition to identifying potential cell damage during antibiotic treatment.

show abstract

“…Prior research has shown that biofilm exposure to synthetic surfactants can decrease respiratory activity temporarily, with full recovery occurring after 12 h [40]. Conversely, antibiotic exposure temporarily increased respiration for several hours for affected singlespecies biofilms [41]. Biomass has similarly been negatively affected by surfactant exposure over a short time period.…”

Section: Discussionmentioning

confidence: 99%

Rhamnolipids Mediate the Effects of a Gastropod Grazer in Regards to Carbon–Nitrogen Stoichiometry of Intertidal Microbial Biofilms

et al. 2022

View full text Add to dashboard Cite

Microbial biofilms have co-evolved with grazing animals, such as gastropods, to develop mutually beneficial relationships. Although microbial biofilms demonstrate resilience and resistance to chemical exposure, pre-existing relationships can be negatively affected by chemical input. In this study, we determined how the grazer, Littorina littorea (common periwinkle sea snail), and a biological surfactant (rhamnolipid) interact on a phototrophic marine biofilm. Biofilms were cultured in 32 twenty-liter buckets at the Queen’s University Marine Laboratory in Portaferry, Northern Ireland on clay tiles that were either exposed to 150 ppm of a rhamnolipid solution or that had no chemical exposure. L. littorea were added into half of the buckets, and biofilms were developed over 14 days. Biofilms exposed to grazing alone demonstrated high tolerance to the disturbance, while those growing on rhamnolipid-exposed substrate demonstrated resistance but experienced slight declines in carbon and stoichiometric ratios. However, when exposed to both, biofilms had significant decreases in stoichiometry and declined in productivity and respiration. This is problematic, as continuing marine pollution increases the likelihood that biofilms will be exposed to combinations of stressors and disturbances. Loss of biofilm productivity within these areas could lead to the loss of an important food source and nutrient cycler within the marine ecosystem.

show abstract

Detection of respiration changes inside biofilms with microelectrodes during exposure to antibiotics

Cited by 6 publications

References 23 publications

Conceptual Model of Biofilm Antibiotic Tolerance That Integrates Phenomena of Diffusion, Metabolism, Gene Expression, and Physiology

Conceptual Model of Biofilm Antibiotic Tolerance That Integrates Phenomena of Diffusion, Metabolism, Gene Expression, and Physiology

Label-Free Detection of Single Living Bacteria: Single-Entity Electrochemistry Targeting Metabolic Products

Rhamnolipids Mediate the Effects of a Gastropod Grazer in Regards to Carbon–Nitrogen Stoichiometry of Intertidal Microbial Biofilms

Contact Info

Product

Resources

About