Biofilm formation and serum susceptibility in Pseudomonas aeruginosa

Mikučionytė, Greta; Dambrauskienė, Asta; Skrodenienė, Erika; Vitkauskienė, Astra

doi:10.2478/s11536-013-0241-y

Cited by 4 publications

(5 citation statements)

References 26 publications

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“…In our study, biofilm production was 29.2% from wound, 37.5%from burn, 60.6% from urine and 57.9% from ETA specimens . We didn't find any statistically significant differences in biofilm production among the P. aeruginosa strains recovered from different specimens, which comes in agreement with the result of Mikucionyte et al (18).…”

Section: Discussionsupporting

confidence: 92%

Antibiotic resistance and ndvB gene expression among biofilm producing Pseudomonas aeruoginosa isolates

Mohammed¹,

Alla²

2016

Af J Clin Exp Micro

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A novel antibiotic resistant mechanism among biofilms is glucan-mediated sequestration in which ndvB gene encodes a glucosyltransferase involved in the formation of this glucans. We studied the biofilm formation and antibiotic susceptibility pattern of P. aeruginosa isolated from clinical samples, and measured the expression of ndvB gene among biofilm forming isolates and their planktonic counterparts. The study was conducted on 92 P. aeruginosa isolates. Biofilm was measured using tissue culture plate method. Antibiotic susceptibility of biofilm positive isolates and planktonic counterparts for ciprofloxacin, tobramycin and gentamycin was tested using tube microdilution method. Expression of ndvB gene was measured using Syper green real time PCR. We found that 44 isolates (47.8%) of P. aeruginosa were biofilm positive. The biofilm formation was high among urine, endotracheal tube aspirate and burn isolates compared to isolates of wound specimens, with statistically nonsignificant differences. None of biofilm forming isolates was susceptible to the 3 antibiotics compared to the presence of susceptible isolates among the planktonic counterpart (18/40.9% for ciprofloxacin, 12/27.3% for tobramycin and 13/29.5% for gentamycin). Expression of ndvB gene was significantly high in biofilm isolates than their corresponding counterpart, with significant correlations with minimal biofilm inhibitory concentration (MBIC) values of cibrofloxacin (r=+ 0.65, p), tobramycin (r= + 0.54 p) and gentamycin (r=+ 0.77, p).From this study we concluded that biofilm formation is an important character of P. aeruginosa that is a main cause of antibiotic resistance especially in isolates from catheterized urine , wound and endotracheal tube aspirate. NdvB gene expression is a mechanism of resistance to antibiotics in P. aeruginosa biofilms.

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Section: Discussionsupporting

confidence: 92%

Antibiotic resistance and ndvB gene expression among biofilm producing Pseudomonas aeruoginosa isolates

Mohammed¹,

Alla²

2016

Af J Clin Exp Micro

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“…They showed that, at early stages of growth, serum can repress the expression of many P. aeruginosa genes, and it can enhance them in the late phase. HF's ability to enhance P. aeruginosa susceptibility to human serum becomes even more important in light of the fact that serum-resistant phenotypes of P. aeruginosa are more frequently isolated from wounds and blood than infections at other sites [54]. Wound infections are believed to occur when microbial burden exceeds the innate clearance capacity of the host immune system [10].…”

Section: Discussionmentioning

confidence: 99%

Antipathogenic Potential of a Polyherbal Wound-Care Formulation (Herboheal) against Certain Wound-Infective Gram-Negative Bacteria

Patel

Joshi

Kothari

2019

Advances in Pharmacological Sciences

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This study investigated antipathogenic efficacy of a polyherbal wound-healing formulation Herboheal against three multidrug-resistant strains of gram-negative bacterial pathogens associated with wound infections. Herboheal was evaluated for its quorum-modulatory potential against three different human-pathogenic bacteria, first in vitro through the broth dilution assay and then in vivo in the model host Caenorhabditis elegans. Herboheal at ≥0.1% v/v was able to inhibit (19–55%) in vitro production of quorum sensing-regulated pigments in all these bacteria and seemed to interfere with bacterial quorum sensing by acting as a signal-response inhibitor. This formulation could compromise haemolytic activity of all three bacteria by ∼18–69% and induced their catalase activity by ∼8–21%. Herboheal inhibited P. aeruginosa biofilm formation up to 40%, reduced surface hydrophobicity of P. aeruginosa cells by ∼9%, and also made them (25%) more susceptible to lysis by human serum. Antibiotic susceptibility of all three bacteria was modulated owing to pretreatment with Herboheal. Exposure of these test pathogens to Herboheal (≥0.025% v/v) effectively reduced their virulence towards the nematode Caenorhabditis elegans. Repeated subculturing of P. aeruginosa on the Herboheal-supplemented growth medium did not induce resistance to Herboheal in this mischievous pathogen, and this polyherbal extract was also found to exert a post-extract effect on P. aeruginosa, wherein virulence of the Herboheal-unexposed daughter cultures, of the Herboheal-exposed parent culture, was also found to be attenuated. Overall, this study indicates Herboheal formulation to be an effective antipathogenic preparation and validates its indicated traditional therapeutic use as a wound-care formulation.

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“…; Mikucionyte et al . ), mainly for microbial strains recovered from blood (Dolan ). It is known that organic components, such as proteins (albumin, fibrinogen, fibronectin and laminin) and platelets, play a key role as matrix determinants important in microbial adhesion and biofilm composition (Dolan ).…”

Section: Discussionmentioning

confidence: 99%

“…The authors attested that bacterial adhesion, aggregation and proliferation in the thin biofilm layer were increased in the presence of serum, leading to an in vitro thick mature biofilm. Serum components may promote biofilm formation (Samaranayake et al 2013;Mikucionyte et al 2014), mainly for microbial strains recovered from blood (Dolan 2002). It is known that organic components, such as proteins (albumin, fibrinogen, fibronectin and laminin) and platelets, play a key role as matrix determinants important in microbial adhesion and biofilm composition (Dolan 2002).…”

Section: Discussionmentioning

confidence: 99%

In vitro activity of antimicrobial‐impregnated catheters against biofilms formed by KPC‐producing Klebsiella pneumoniae

et al. 2019

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Aim To evaluate the activity and effectiveness of impregnated central venous catheters (CVC) against Klebsiella pneumoniae biofilms. Methods and Results The antimicrobial activity and durability of impregnated‐CVCs were evaluated over time and the size of zones of inhibition (ZI) was measured. Biofilm formation was observed by quantitative culture and also by scanning electron microscopy. The catheters impregnated with chlorhexidine/silver sulfadiazine (CHX/SS) reduced bacteria counts by 0·3 log and were most effective (P < 0·01) against Klebsiella pneumoniae biofilms N‐acetylcysteine/levofloxacin (NAC/LEV) catheters. It was observed that the catheter impregnated with NAC/LEV had initially the largest average ZI size being statistically significant (P < 0·01). The NAC/LEV combination remained active until day 30, whereas the combination of CHX/SS was completely inactivated from day 15 on. Conclusions The NAC/LEV combination showed greater durability on the catheters, but it was the CHX/SS combination that had the greater initial efficacy in bacterial inhibition. It was also observed that NAC/LEV‐impregnated catheters do not prevent the emergence of resistant subpopulations inside the inhibition halos during antimicrobial susceptibility tests. Significance and Impact of the Study Our results highlighted that the in vitro efficacy of antimicrobial‐impregnated CVCs is limited by time and that their colonization occurred earlier than expected. Our data also demonstrated that NAC/LEV remained active until day 30 of evaluation and CHX/SS combination was completely inactivated from day 15 on. Our findings suggested that implantable devices should be carefully used by medical community.

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Biofilm formation and serum susceptibility in Pseudomonas aeruginosa

Cited by 4 publications

References 26 publications

Antibiotic resistance and <i>ndvB</i> gene expression among biofilm producing <i>Pseudomonas aeruoginosa</i> isolates

Antibiotic resistance and <i>ndvB</i> gene expression among biofilm producing <i>Pseudomonas aeruoginosa</i> isolates

Antipathogenic Potential of a Polyherbal Wound-Care Formulation (Herboheal) against Certain Wound-Infective Gram-Negative Bacteria

In vitro activity of antimicrobial‐impregnated catheters against biofilms formed by KPC‐producing Klebsiella pneumoniae

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