A Sandwich Cup Method for the Penetration Assay of Antimicrobial Agents through <i>Pseudomonas</i> Exopolysaccharides

Kumon, Hiromi; Tomochika, Ken Ichi; Matunaga, Tosiyuki; Ogawa, Masaru; Ohmori, Hiroyuki

doi:10.1111/j.1348-0421.1994.tb01831.x

Cited by 127 publications

(84 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Our data show that LVX and GAT have signifi cant inhibitory effect against both BLNAS and BLNAR NTHi within biofi lms compared to AMP, CTX, ERY and CLR. Our results agree with previous investigations that studied P. aeruginosa biofi lm, as it has been shown that fl uoroquinolones can penetrate exopolysaccharides (Kumon et al 1994;Yassien et al 1995). Since the use of fl uoroquinolones in young children is limited in many countries because of adverse neurological side effects, the clinical antimicrobial effectiveness against BLNAS and BLNAR NTHi in biofi lms has not been confi rmed.…”

Section: Discussionsupporting

confidence: 79%

Antimicrobial Effect of Fluoroquinolones for the Eradication of Nontypeable Haemophilus Influenzae Isolates within Biofilms

Kaji

Watanabe

Apicella

et al. 2008

Tohoku J. Exp. Med.

View full text Add to dashboard Cite

Biofi lms can be defi ned as communities of microorganisms attached to a surface. Those bacterial biofi lms cause serious problems, such as antibiotic resistance and medical devicerelated infections. Nontypeable Haemophilus infl uenzae (NTHi) is an important pathogen in respiratory infections, as it forms biofi lms both in vitro and in vivo such as human middle ear. Recent reports indicate that otitis media, paranasal sinusitis and lower respiratory tract infections caused by Haemophilus infl uenzae have become more diffi cult to treat with oral antibiotic therapy. However, there has been no attention given to antibiotic eradication of NTHi biofi lm. To investigate the antimicrobial effect of various antibiotics against NTHi biofi lm formation, we conducted the following comparative study using both β -lactamase-negative ampicillin (AMP)-susceptible (BLNAS) and AMP-resistant (BLNAR) NTHi strains. In a microtiter biofi lm assay, both levofl oxacin and gatifl oxacin, of the fl uoroquinolone antibiotic group, signifi cantly inhibited biofi lm formation by BLNAS and BLNAR NTHi in a dose-dependent fashion compared to ampicillin of the penicillin antibiotic group, cefotaxime of the cephalosporin antibiotic group, and both erythromycin and clarithromycin of the macrolide antibiotic group. Furthermore, in fl ow cell chamber studies, confocal laser scanning microscopy counted survival bacteria in mature biofi lm had been treated with gatifl oxacin, ampicillin, cefotaxime and erythromycin. Only gatifl oxacin completely killed the BLNAR NTHi isolates within biofi lms without regard to the thickness of biofi lm formation. The results of this study suggest that fl uoroquinolones potentially have a role in therapy against diseases caused by both BLNAS and BLNAR NTHi isolates within biofi lms.

show abstract

Section: Discussionsupporting

confidence: 79%

Antimicrobial Effect of Fluoroquinolones for the Eradication of Nontypeable Haemophilus Influenzae Isolates within Biofilms

Kaji

Watanabe

Apicella

et al. 2008

Tohoku J. Exp. Med.

View full text Add to dashboard Cite

show abstract

“…For instance, the effect of an antibiotic can be reduced after adsorption on the matrix due to electrical interactions with polymers surrounding biofilm bacteria (20,36). Other studies reported slow penetration of positively charged aminoglycosides through negatively charged polymers of the biofilm matrix (37,38). In this regard, the chemical structure of the biofilm matrix is important, and it has been shown that even for a single pathogen, different types of exopolysaccharides can be involved, depending on the environment surrounding the biofilm (39).…”

Section: Biofilm Recalcitrance Is Multifactorialmentioning

confidence: 99%

Biofilm-Related Infections: Bridging the Gap between Clinical Management and Fundamental Aspects of Recalcitrance toward Antibiotics

Lebeaux

Ghigo

Beloin

2014

Microbiol Mol Biol Rev

1,009

862

View full text Add to dashboard Cite

International audienceSurface-associated microbial communities, called biofilms, are present in all environments. Although biofilms play an important positive role in a variety of ecosystems, they also have many negative effects, including biofilm-related infections in medical settings. The ability of pathogenic biofilms to survive in the presence of high concentrations of antibiotics is called "recalcitrance" and is a characteristic property of the biofilm lifestyle, leading to treatment failure and infection recurrence. This review presents our current understanding of the molecular mechanisms of biofilm recalcitrance toward antibiotics and describes how recent progress has improved our capacity to design original and efficient strategies to prevent or eradicate biofilm-related infections

show abstract

“…Biofilm structure can prevent an applied antimicrobial agent from reaching the entire bacterial population by mechanisms such as a neutralizing reaction with components of the biofilm [29,10], synthesis of an antimicrobial degrading enzyme [16,3] and adsorption of the antimicrobial by the exo-polymeric substance (EPS) [19]. There have been several mathematical models of biofilm disinfection that include diffusion and various antimicrobialdegrading reactions [25,12,6].…”

Section: Introductionmentioning

confidence: 99%

Effects of persister formation on bacterial response to dosing

Cogan

2006

Journal of Theoretical Biology

View full text Add to dashboard Cite

Almost all moist surfaces are colonized by microbial biofilms. Biofilms are implicated in cross-contamination of food products, biofouling and various human infections such as dental cavities, ulcerative colitis and chronic respiratory infections. The recalcitrance of biofilms to typical antibiotic and antimicrobial treatments is one focus of current investigations. Neither reaction-diffusion limitation nor heterogeneities in growth-rate explain the observed tolerance. Another hypothesis is that specialized 'persister' cells, which are extremely tolerant of antimicrobials, are the source of resistance.In this investigation, we describe the formation of 'persister' cells which neither grow nor die in the presence of antibiotics. We propose that these cells are of a different phenotype whose expression is regulated by the growth rate and the antibiotic concentration. Based on several experiments describing the dynamics of persister cells, we introduce a mathematical model that is used to describes the effect of a periodic dosing regiment. Results from our analysis indicate that the relative dose/withdrawal times are important in determining the effectiveness of such a treatment. A reduced model is also introduced and the similar behavior is demonstrated analytically.

show abstract

A Sandwich Cup Method for the Penetration Assay of Antimicrobial Agents through Pseudomonas Exopolysaccharides

Cited by 127 publications

References 16 publications

Antimicrobial Effect of Fluoroquinolones for the Eradication of Nontypeable Haemophilus Influenzae Isolates within Biofilms

Antimicrobial Effect of Fluoroquinolones for the Eradication of Nontypeable Haemophilus Influenzae Isolates within Biofilms

Biofilm-Related Infections: Bridging the Gap between Clinical Management and Fundamental Aspects of Recalcitrance toward Antibiotics

Effects of persister formation on bacterial response to dosing

Contact Info

Product

Resources

About