Effects of Mupirocin at Subinhibitory Concentrations on Biofilm Formation in <i>Pseudomonas aeruginosa</i>

Abstract

Background: Subinhibitory concentrations of mupirocin can suppress flagellar formation in Pseudomonas aeruginosa. In this study, we evaluated the effect of mupirocin on biofilm formation in P. aeruginosa. Methods:P. aeruginosa PAO-1 (MIC, >1,024 µg/ml for mupirocin) was used. Viable bacteria adhering or forming biofilm on a Cell Desk were counted and observed by scanning electron microscopy. Results: With or without continuous exposure to 256 µg/ml of mupirocin, counts of adherent and/or biofilm-forming bacteria showed no difference until day 10. Whereas biofilm formation with glycocalyx was observed on day 6–10 without mupirocin, mupirocin reduced biofilm formation and glycocalyx production for 10 days. Conclusions: Subinhibitory concentrations of mupirocin can reduce biofilm formation in vitro in P. aeruginosa.

Resistances to benzalkonium chloride of bacteria dried with food elements on stainless steel surface

“…Particularly, there are many reports about the resistances of biofilms of Ps. aeruginosa (Ishikawa & Horii, 2005;Landry, An, Hupp, Singh, & Parsek, 2006), Stap. aureus (Shanks et al, 2005;Valle et al, 2003) and Listeria monocytogenes (Carpentier & Chassaing, 2004;Chemielewski & Frank, 2006) because of their strong resistances against disinfectants and for serious medical reasons, such as nosocomial infections.…”

Modulation of secreted virulence factor genes by subinhibitory concentrations of antibiotics in Pseudomonas aeruginosa

“…It is generally perceived that naturally occurring antibiotics are weapons in intermicrobial competition, and should reduce fitness and virulence of pathogens even at subinhibitory concentrations. Many previous reports support this hypothesis (Carfartan et al, 2004;Fonseca et al, 2004;Wozniak and Keyser 2004;Ishikawa and Horii, 2005), but a few studies have shown that some antibiotics at subinhibitory concentrations can activate the expression of some important virulence genes in Salmonella typhimurium and E. coli (Goh et al, 2002) and enhance biofilm formation (Hoffman et al, 2005). There is evidence suggesting that antibiotics act as signal molecules regulating bacterial gene expression and modulating bacterial fitness (Linares et al, 2006).…”

The effect of subminimal inhibitory concentrations of antibiotics on the adherence ability of Pseudomonas aeruginosa to epithelial cells in vitro

“…Subinhibitory concentrations of antibiotics may affect various bacterial virulence factors. They can act on the morphology and the antigenicity of the bacteria (11,12), on the growth of bacteria (13), on the synthesis and secretion of enzymes (14,15) and can act on bacterial adherence (16,17). All these factors contribute to the reduction of bacterial pathogenicity.…”