Investigation of ciprofloxacin penetration into Pseudomonas aeruginosa biofilms

Abstract

Bacterial infections associated with indwelling medical devices often demonstrate an intrinsic resistance to antimicrobial therapies. In order to explore the possibility of transport limitation to biofilm bacteria as a contributing factor, the penetration of a fluoroquinolone antibiotic, ciprofloxacin, through Pseudomonas aeruginosa biofilms was investigated. Attenuated total reflection Fourier transform infrared (ATR/FT-IR) spectrometry was employed to monitor bacterial colonization of a germanium substratum, transport of ciprofloxacin to the biofilm-substratum interface, and interaction of biofilm components with the antibiotic in a flowing system. Transport of the antibiotic to the biofilm-substratum interface during the 21-min exposure to 100 micrograms/ml was found to be significantly impeded by the biofilm. Significant changes in IR bands of the biofilm in regions of the spectrum associated with RNA and DNA vibrational modes appeared following exposure to the antibiotic, indicating chemical modification of biofilm components. These results suggest that transport limitations may be an important factor in the antimicrobial resistance of biofilm bacteria and that ATR/FT-IR spectrometry may be used to follow the time course of antimicrobial action in biofilms in situ.

Evaluation of Hospital Acquired Pseudomonas Infection in Paraplegic and Orthopaedic Cases

“…Similarly increased use of tobramycin, carbenicillin, norfloxacin and ciprofloxacin amongst SCIC patients showed fairly high resistance as compared to orthopaedic cases. Bacterial infections associated with indwelling medical devices often demonstrate an intrinsic resistance to anti-microbial therapies due to formation of biofilms [20]. SCIC patients with indwelling catheters showed higher resistance to various antibiotics probably due to poor penetration of Pseudomonas aeruginosa biofilms .…”

Mechanisms Determining Bacterial Biofilm Resistance to Antimicrobial Factors

“…DeBeer et al (1994) observed this phenomenon investigating the rate of penetration of chlorine into Pseudomonas aeruginosa/Klebsiella pneumoniae biofilm matrix. Also Suci et al (1994) noticed transport limitation of ciprofloxacin through Pseudomonas aeruginosa biofilm. In this study, during the 21-min exposure, the presence of the antibiotic in periphery region of tested biofilm reached only 20% of ciprofloxacin concentration in the bulk medium (Suci et al, 1994).…”

“…Also Suci et al (1994) noticed transport limitation of ciprofloxacin through Pseudomonas aeruginosa biofilm. In this study, during the 21-min exposure, the presence of the antibiotic in periphery region of tested biofilm reached only 20% of ciprofloxacin concentration in the bulk medium (Suci et al, 1994). Gilbert et al (1989) used perfused biofilm fermentors, in combine with continuous culture and observed that much of resistance of Gram-positive and Gramnegative biofilms was associated with the presence of nutrient-starved microocolonies.…”

Evaluation of the Biocorrosion Inhibition Potential of Ethanol Extract of Ganoderma tropicum

“…Most of the biocides available for biocorrosion control are ineffective against microbial biofims. This is mainly because some microorganisms in biofilms are shielded from the actions of biocides by the protective extracellular polymeric substances (EPS) coverings and extracellular enzymes present in the matrix (Suci et al, 1994;Anderson and O'Toole, 2008). New strategies in controlling biocorrosion are centered on keeping the microorganisms from forming biofilms, or by dispersing them from biofilms to render them more susceptible to the biocide.…”