ABSTRACT
Nosocomial infections (NIs) have been defined as infections ocuurring shortly after hospitalization or discharging from the hospital. It is associated with increased morbidities and mortalities. Proteus mirabilis considered as the hospital-acquired pathogen. The purpose of this study was to investigate the effect of Lactobacillus acidophilus-derived biosurfactant on P. mirabilis biofilm formation and flhDC/rsmA expression level (P. mirabilis standard strain ATCC 7002 and urinary infection isolated P. mirabilis strains). One of the potential strategies for the prevention of nosocomial infections is the use of probiotics. L. acidophilus was selected as a probiotic strain to produce biosurfactants. A biosurfactant reduces the adhesion of strains to microtiter plate and glass slide surfaces due to the reduction of surface tension. By using Real time PCR quantitation method we showed that biosurfactant significantly reduced rsmA expression whereas increased flhDC expression in P. mirabilis isolates. Several properties of P. mirabilis cells (biofilm formation, adhesion, and gene expression) were changed after L. acidophilus- derived biosurfactant treatment. In this study we showed that biosurfacant treatment can pave the way for a possible control of biofilm development. Based on our findings, we suggest that the prepared biosurfactant may interfere with adhesion of P. mirabilis to catheters and other devices.
Subject(s)
Cross Infection , Urinary Tract Infections , Biofilms , Female , Humans , Lactobacillus , Male , Proteus mirabilisABSTRACT
BACKGROUND AND OBJECTIVES: Serratia marcescens, a potentially pathogenic bacterium, benefits from its swarming motility and resistance to antibiotic as two important virulence factors. Inappropriate use of antibiotics often results in drug resistance phenomenon in bacterial population. Use of probiotic bacteria has been recommended as partial replacement. In this study, we investigated the effects of some lactobacilli culture supernatant on swarming, motility and antibiotic resistance of S. marcescens. MATERIALS AND METHODS: Antimicrobial activity of lactobacilli supernatant and susceptibility testing carried out on S. marcescens isolates. Pretreatment effect of lactobacilli culture supernatant on antibiotic - resistance pattern in S. marcescens was determined by comparison of the MIC of bacteria before and after the treatment. RESULTS: Our results showed that pretreatment with L. acidophilus ATCC 4356 supernatant can affect the resistance of Serratia strains against ceftriaxone, but it had no effect on the resistance to other antibiotics. Furthermore, culture supernatant of lactobacilli with concentrations greater than 2%, had an effect on the swarming ability of S. marcescens ATCC 13880 and inhibited it. CONCLUSION: Probiotic bacteria and their metabolites have the ability to inhibit virulence factors such as antibiotic resistance and swarming motility and can be used as alternatives to antibiotics.
ABSTRACT
OBJECTIVES: Serratia marcescens is one of the nosocomial pathogen with the ability to form biofilm which is an important feature in the pathogenesis of S. marcescens. The aim of this study was to determine the anti-adhesive properties of a biosurfactant isolated from Lactobacillus acidophilus ATCC 4356, on S. marcescens strains. MATERIALS AND METHODS: Lactobacillus acidophilus ATCC 4356 was selected as a probiotic strain for biosurfactant production. Anti-adhesive activities was determined by pre-coating and co- incubating methods in 96-well culture plates. RESULTS: The FTIR analysis of derived biosurfactant revealed the composition as protein component. Due to the release of such biosurfactants, L. acidophilus was able to interfere with the adhesion and biofilm formation of the S. marcescens strains. In co-incubation method, this biosurfactant in 2.5 mg/ml concentration showed anti-adhesive activity against all tested strains of S. marcescens (P<0.05). CONCLUSION: Our results show that the anti-adhesive properties of L. acidophilus biosurfactant has the potential to be used against microorganisms responsible for infections in the urinary, vaginal and gastrointestinal tracts, as well as skin, making it a suitable alternative to conventional antibiotics.
