Effect of biofilm culture upon the susceptibility of <i>Staphylococcus epidermidis</i> to tobramycin

Duguid, I.G.; Evans, Elizabeth; Brown, M. R. W.; Gilbert, Peter

doi:10.1093/jac/30.6.803

Cited by 96 publications

(55 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…If slow penetration is the sole basis for biofilm tolerance, we would anticipate that dispersal of a biofilm would immediately and completely restore its full planktonic susceptibility. This behavior has been reported in some studies (2,16,42,45).…”

Section: Resultssupporting

confidence: 82%

A Three-Dimensional Computer Model of Four Hypothetical Mechanisms Protecting Biofilms from Antimicrobials

Chambless

Hunt

Stewart

2006

Appl Environ Microbiol

150

110

View full text Add to dashboard Cite

Four hypothetical mechanisms for protection of biofilms against antimicrobials were incorporated into a three-dimensional model of biofilm growth and development. The model integrated processes of substrate utilization, diffusion, growth, cell migration, death, and detachment in a cellular automaton framework. Compared to simulations of unprotected biofilms, each of the protective mechanisms provided some tolerance to antimicrobial action. When the mechanisms were compared to each other, the behaviors of the four protective mechanisms produced distinct shapes of killing curves, nonuniform spatial patterns of survival and cell type distribution, and anticipated susceptibility patterns for dispersed biofilm cells. The differences between the protective mechanisms predicted in these simulations could guide the design of experiments to discriminate antimicrobial tolerance mechanisms in biofilms. Each of the mechanisms could be a plausible avenue of biofilm protection.

show abstract

Section: Resultssupporting

confidence: 82%

A Three-Dimensional Computer Model of Four Hypothetical Mechanisms Protecting Biofilms from Antimicrobials

Chambless

Hunt

Stewart

2006

Appl Environ Microbiol

150

110

View full text Add to dashboard Cite

show abstract

“…Hoyle et al (83) found that dispersed bacterial cells were 15 times more susceptible to tobramycin than were cells in intact biofilms. DuGuid et al (57) examined Staphylococcus epidermidis susceptibility to tobramycin and concluded that the organization of cells within biofilms could in part explain the resistance of this organism to this antimicrobial agent.…”

Section: Delayed Penetration Of the Antimicrobial Agentmentioning

confidence: 99%

Biofilms: Survival Mechanisms of Clinically Relevant Microorganisms

2002

View full text Add to dashboard Cite

Though biofilms were first described by Antonie van Leeuwenhoek, the theory describing the biofilm process was not developed until 1978. We now understand that biofilms are universal, occurring in aquatic and industrial water systems as well as a large number of environments and medical devices relevant for public health. Using tools such as the scanning electron microscope and, more recently, the confocal laser scanning microscope, biofilm researchers now understand that biofilms are not unstructured, homogeneous deposits of cells and accumulated slime, but complex communities of surface-associated cells enclosed in a polymer matrix containing open water channels. Further studies have shown that the biofilm phenotype can be described in terms of the genes expressed by biofilm-associated cells. Microorganisms growing in a biofilm are highly resistant to antimicrobial agents by one or more mechanisms. Biofilm-associated microorganisms have been shown to be associated with several human diseases, such as native valve endocarditis and cystic fibrosis, and to colonize a wide variety of medical devices. Though epidemiologic evidence points to biofilms as a source of several infectious diseases, the exact mechanisms by which biofilm-associated microorganisms elicit disease are poorly understood. Detachment of cells or cell aggregates, production of endotoxin, increased resistance to the host immune system, and provision of a niche for the generation of resistant organisms are all biofilm processes which could initiate the disease process. Effective strategies to prevent or control biofilms on medical devices must take into consideration the unique and tenacious nature of biofilms. Current intervention strategies are designed to prevent initial device colonization, minimize microbial cell attachment to the device, penetrate the biofilm matrix and kill the associated cells, or remove the device from the patient. In the future, treatments may be based on inhibition of genes involved in cell attachment and biofilm formation

show abstract

“…However, these observations do not permit us to determine which metabolic activity in CoNS should be considered normal or a reference metabolic state. As mentioned above, there is a large amount of experimental evidence that indicates that metabolically less active bacteria have reduced susceptibility to many antibiotics (3,4,(9)(10)(11). Consequently, the observed decreased metabolic activity during late FBI can explain at least in part why these infections are so difficult to eradicate with conventional antibiotic treatment.…”

Section: Discussionmentioning

confidence: 99%

“…The exact nature of the resistance remains unclear, but decreased metabolic activity of the foreign-body-associated bacteria is postulated to be an important factor. Numerous reports have demonstrated that metabolically less active bacteria are tolerant to the killing effects of most antibiotics (3,4,(9)(10)(11). One paper suggested that there was decreased metabolic activity of Klebsiella pneumoniae after prolonged incubation on polycarbonate filter membranes (28).…”

mentioning

confidence: 99%

Metabolic Activity of Staphylococcus epidermidis Is High during Initial and Low during Late Experimental Foreign-Body Infection

et al. 2004

View full text Add to dashboard Cite

Foreign-body infection (FBI) is notoriously resistant to eradication by antibiotic treatment. It is hypothesized that reduced bacterial metabolic activity contributes to this resistance. We examined the metabolic activity of Staphylococcus epidermidis in 204 samples recovered during in vitro foreign-body colonization and in 424 samples recovered during in vivo FBI in a rat model. Metabolic activity was measured by determining the amount of 16S rRNA per genome by quantitative PCR. The initial foreign-body-associated growth proved to be a metabolically active process, both in vitro and in vivo. The initial 16S rRNA content was similar to that observed during in vitro exponential-growth phase. However, during late in vivo FBI, a 114-fold (P Ͻ Ͻ 0.0001) decrease in the 16S rRNA content was observed, indicating that there was markedly decreased metabolic activity. This decreased metabolic activity during late FBI can explain at least in part why such infections are so difficult to eradicate with conventional antibiotic treatment.

show abstract

Effect of biofilm culture upon the susceptibility of Staphylococcus epidermidis to tobramycin

Cited by 96 publications

References 0 publications

A Three-Dimensional Computer Model of Four Hypothetical Mechanisms Protecting Biofilms from Antimicrobials

A Three-Dimensional Computer Model of Four Hypothetical Mechanisms Protecting Biofilms from Antimicrobials

Biofilms: Survival Mechanisms of Clinically Relevant Microorganisms

Metabolic Activity of Staphylococcus epidermidis Is High during Initial and Low during Late Experimental Foreign-Body Infection

Contact Info

Product

Resources

About