Biofilm formation and susceptibility towards antimicrobial agents in local clinical isolates of staphylococcus epidermidis

2012 ◽  
Author(s):  
Aziyah Abdul-Aziz ◽  
Sharifah Aminah Syed Mohamad ◽  
Sahlawati Mustakim
Keyword(s):  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Clinical Isolates

scholarly journals Evaluation of Antibiotic Resistance Pattern, Alginate and Biofilm Production in Clinical Isolates of Pseudomonas aeruginosa

2021 ◽  
Author(s):  
Fateme DAVARZANI ◽  
Navid SAIDI ◽  
Saeed BESHARATI ◽  
Horieh SADERI ◽  
Iraj RASOOLI ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Resistance Pattern ◽  
Alginate Production ◽  
Opportunistic Bacteria

Background: Pseudomonas aeruginosa is one of the most common opportunistic bacteria causing nosocomial infections, which has significant resistance to antimicrobial agents. This bacterium is a biofilm and alginate producer. Biofilm increases the bacterial resistance to antibiotics and the immune system. Therefore, the present study was conducted to investigate the biofilm formation, alginate production and antimicrobial resistance patterns in the clinical isolates of P. aeruginosa. Methods: One hundred isolates of P. aeruginosa were collected during the study period (from Dec 2017 to Jul 2018) from different clinical samples of the patients admitted to Milad and Pars Hospitals at Tehran, Iran. Isolates were identified and confirmed by phenotypic and genotypic methods. Antimicrobial susceptibility was specified by the disk diffusion method. Biofilm formation and alginate production were measured by microtiter plate and carbazole assay, respectively. Results: Sixteen isolates were resistant to all the 12 studied antibiotics. Moreover, 31 isolates were MultidrugResistant (MDR). The highest resistance rate was related to ofloxacin (36 isolates) and the least resistance was related to piperacillin-tazobactam (21 isolates). All the isolates could produce the biofilm and alginate. The number of isolates producing strong, medium and weak biofilms was equal to 34, 52, and 14, respectively. Alginate production was more than 400 μg/ml in 39 isolates, 250-400 μg/ml in 51 isolates and less than 250 μg/ml in 10 isolates. Conclusion: High prevalence of MDR, biofilm formation, and alginate production were observed among the clinical isolates of P. aeruginosa. The results also showed a significant relationship between the amount of alginate production and the level of biofilm formation.

scholarly journals Effect of Algae and Plant Lectins on Planktonic Growth and Biofilm Formation in Clinically Relevant Bacteria and Yeasts

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Mayron Alves Vasconcelos ◽  
Francisco Vassiliepe Sousa Arruda ◽  
Victor Alves Carneiro ◽  
Helton Colares Silva ◽  
Kyria Santiago Nascimento ◽  
...  
Keyword(s):  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Klebsiella Oxytoca ◽  
Hypnea Musciformis ◽  
Planktonic Growth ◽  
Viable Cells ◽  
Colony Forming Units ◽  
Different Characteristics ◽  
Vatairea Macrocarpa

This study aimed to evaluate the abilities of plant and algae lectins to inhibit planktonic growth and biofilm formation in bacteria and yeasts. Initially, ten lectins were tested onStaphylococcus epidermidis, Staphylococcus aureus, Klebsiella oxytoca, Pseudomonas aeruginosa, Candida albicans, andC. tropicalisat concentrations of 31.25 to 250 μg/mL. The lectins fromCratylia floribunda(CFL),Vatairea macrocarpa(VML),Bauhinia bauhinioides(BBL),Bryothamnion seaforthii(BSL), andHypnea musciformis(HML) showed activities against at least one microorganism. Biofilm formation in the presence of the lectins was also evaluated; after 24 h of incubation with the lectins, the biofilms were analyzed by quantifying the biomass (by crystal violet staining) and by enumerating the viable cells (colony-forming units). The lectins reduced the biofilm biomass and/or the number of viable cells to differing degrees depending on the microorganism tested, demonstrating the different characteristics of the lectins. These findings indicate that the lectins tested in this study may be natural alternative antimicrobial agents; however, further studies are required to better elucidate the functional use of these proteins.

scholarly journals The Bacterial Insertion Sequence Element IS256 Occurs Preferentially in Nosocomial Staphylococcus epidermidis Isolates: Association with Biofilm Formation and Resistance to Aminoglycosides

2004 ◽  
Vol 72 (2) ◽  
pp. 1210-1215 ◽  
Author(s):  
Svetlana Kozitskaya ◽  
Seung-Hak Cho ◽  
Katja Dietrich ◽  
Reinhard Marre ◽  
Kurt Naber ◽  
...  
Keyword(s):  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Insertion Sequence ◽  
Spontaneous Mutation ◽  
Clinical Isolates ◽  
Healthy Human ◽  
Sequence Element ◽  
Oxacillin Resistance ◽  
Multiple Copies ◽  
Insertion Sequence Element

ABSTRACT Staphylococcus epidermidis is a normal constituent of the healthy human microflora, but it is also the most common cause of nosocomial infections associated with the use of indwelling medical devices. Isolates from device-associated infections are known for their pronounced phenotypic and genetic variability, and in this study we searched for factors that might contribute to this flexibility. We show that mutator phenotypes, which exhibit elevated spontaneous mutation rates, are rare among both pathogenic and commensal S. epidermidis strains. However, the study revealed that, in contrast to those of commensal strains, the genomes of clinical S. epidermidis strains carry multiple copies of the insertion sequence IS256, while other typical staphylococcal insertion sequences, such as IS257 and IS1272, are distributed equally among saprophytic and clinical isolates. Moreover, detection of IS256 was found to be associated with biofilm formation and the presence of the icaADBC operon as well as with gentamicin and oxacillin resistance in the clinical strains. The data suggest that IS256 is a characteristic element in the genome of multiresistant nosocomial S. epidermidis isolates that might be involved in the flexibility and adaptation of the genome in clinical isolates.

scholarly journals Effect of Cinnamon Oil on icaA Expression and Biofilm Formation by Staphylococcus epidermidis

2009 ◽  
Vol 75 (21) ◽  
pp. 6850-6855 ◽  
Author(s):  
Titik Nuryastuti ◽  
Henny C. van der Mei ◽  
Henk J. Busscher ◽  
Susi Iravati ◽  
Abu T. Aman ◽  
...  
Keyword(s):  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Antimicrobial Agents ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Pcr Analysis ◽  
Minimal Bactericidal Concentration ◽  
Cinnamon Oil ◽  
Broth Microdilution Method

ABSTRACT Staphylococcus epidermidis is notorious for its biofilm formation on medical devices, and novel approaches to prevent and kill S. epidermidis biofilms are desired. In this study, the effect of cinnamon oil on planktonic and biofilm cultures of clinical S. epidermidis isolates was evaluated. Initially, susceptibility to cinnamon oil in planktonic cultures was compared to the commonly used antimicrobial agents chlorhexidine, triclosan, and gentamicin. The MIC of cinnamon oil, defined as the lowest concentration able to inhibit visible microbial growth, and the minimal bactericidal concentration, the lowest concentration required to kill 99.9% of the bacteria, were determined using the broth microdilution method and plating on agar. A checkerboard assay was used to evaluate the possible synergy between cinnamon oil and the other antimicrobial agents. The effect of cinnamon oil on biofilm growth was studied in 96-well plates and with confocal laser-scanning microscopy (CLSM). Biofilm susceptibility was determined using a metabolic 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Real-time PCR analysis was performed to determine the effect of sub-MIC concentrations of cinnamon oil on expression of the biofilm-related gene, icaA. Cinnamon oil showed antimicrobial activity against both planktonic and biofilm cultures of clinical S. epidermidis strains. There was only a small difference between planktonic and biofilm MICs, ranging from 0.5 to 1% and 1 to 2%, respectively. CLSM images indicated that cinnamon oil is able to detach and kill existing biofilms. Thus, cinnamon oil is an effective antimicrobial agent to combat S. epidermidis biofilms.

scholarly journals Enhancement of Biofilm Formation by Subinhibitory Concentrations of Macrolides in icaADBC-Positive and -Negative Clinical Isolates of Staphylococcus epidermidis

2010 ◽  
Vol 54 (6) ◽  
pp. 2707-2711 ◽  
Author(s):  
Qian Wang ◽  
Feng-Jun Sun ◽  
Yao Liu ◽  
Li-Rong Xiong ◽  
Lin-Li Xie ◽  
...  
Keyword(s):  
Staphylococcus Epidermidis ◽  
Clinical Relevance ◽  
Biofilm Formation ◽  
Clinical Isolates ◽  
Dependent Manner ◽  
Biofilm Growth ◽  
Subinhibitory Concentrations ◽  
Dose Dependent

ABSTRACT Biofilm formation in Staphylococcus epidermidis is mediated by icaADBC-dependent and -independent pathways. Subinhibitory concentrations of erythromycin, azithromycin, and clarithromycin enhanced, in a dose-dependent manner, the level of biofilm formation by 20% (21/105 isolates) by macrolide-resistant ica-positive and -negative isolates tested in vitro. The presence of ica, however, apparently produced an enhanced effect on biofilm formation. The levels of expression of the biofilm-related genes icaA, atlE, fruA, pyrR, sarA, and sigB were increased in response to erythromycin. The results likely underscore the potential clinical relevance of macrolide-induced biofilm growth.

scholarly journals Phenotypic and Genetic Analysis of Biofilm Formation by Staphylococcus epidermidis

Medicina ◽  
2012 ◽  
Vol 48 (6) ◽  
pp. 45 ◽  
Author(s):  
Iveta Līduma ◽  
Tatjana Tračevska ◽  
Uģis Bērs ◽  
Aija Žileviča
Keyword(s):  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Microtiter Plate ◽  
Clinical Isolates ◽  
Control Group ◽  
Clinical Group ◽  
Clinical Strains ◽  
Implanted Medical Devices ◽  
Important Virulence Factor ◽  
Accumulation Associated Protein

Objective. The most important virulence factor of Staphylococcus epidermidis is their capability to form a biofilm on the surfaces of implanted medical devices. The accumulative phase of biofilm formation is linked to the production of intercellular adhesin encoded by the icaADBC operon and accumulation-associated protein by the aap gene. The aim of the study was to investigate biofilm formation phenotypically and genetically in clinical strains of S. epidermidis in comparison with commensal strains. Material and Methods. The study was carried out in 4 hospitals in Riga, Latvia. In total, 105 clinical strains of Staphylococcus epidermidis isolated from patients’ blood (n=67) and intravenous catheters (n=38) in a case of laboratory-confirmed bacteremia were studied. Moreover, 60 Staphylococcus epidermidis commensal strains isolated from nose epithelium of healthy people were included as a control group. Appearance of the icaA and aap genes was tested by polymerase chain reaction. The microtiter plate method was used. Results. Biofilm formation was detected in 50 (47%) of Staphylococcus epidermidis isolates in the clinical group and 15 (25%) of isolates in the control group (P=0.0049). Among 50 biofilmforming clinical isolates, 46 (92%) were positive for the icaA and/or aap genes. The icaA and aap genes were not found only in 4 strains. Conclusions. The clinical isolates of Staphylococcus epidermidis were more likely to form biofilms than the commensal strains. The carriage of the icaA or aap gene alone, or their absence, is not applicable as a molecular marker for the discrimination invasive Staphylococcus epidermidis strains from contaminants.

scholarly journals Influence of Sub-Inhibitory Concentrations of Antimicrobial Agents on Biofilm Formation in Indwelling Medical Devices

2005 ◽  
Vol 28 (11) ◽  
pp. 1181-1185 ◽  
Author(s):  
M. Henriques ◽  
N. Cerca ◽  
J. Azeredo ◽  
R. Oliveira
Keyword(s):  
Medical Devices ◽  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Antifungal Agents ◽  
Candida Spp ◽  
Antibacterial And Antifungal ◽  
Microbial Agents ◽  
Strain Dependent ◽  
Control Samples

Biofilms of Staphylococcus epidermidis and Candida spp. are two of the most frequent factors of infections associated with the use of indwelling medical devices. Several strategies have been proposed and/or developed to prevent infection. The aim of this study was to compare the effect of sub-inhibitory concentrations of anti-microbial agents on biofilm formation. Biofilms of three strains of S. epidermidis and two of both Candida albicans and Candida dubliniensis were formed in the presence of three antibiotics and two antifungal agents respectively. Based on the control samples, the percentage of biofilm formation inhibition by the different agents was determined and compared. The results showed that the influence of the antibacterial and antifungal agents tested is strain dependent, with the effect of the different agents also varying among strains, even though they have the same mechanism of action.

scholarly journals The effect of Zinc Oxide Nanoparticles on Pseudomonas Aeruginosa Biofilm Formation and Virulence Genes Expression

2020 ◽  
Author(s):  
wedad abdelraheem ◽  
Ebtisam S. Mohamed
Keyword(s):  
Biofilm Formation ◽  
Virulence Genes ◽  
Antimicrobial Agents ◽  
Public Health Problem ◽  
Microtiter Plate ◽  
Clinical Isolates ◽  
Expression Level ◽  
Microdilution Method ◽  
Genes Expression ◽  
Broth Microdilution Method

Abstract Background: Due to increased resistance to antimicrobial agents, infectious disease remains a public health problem worldwide. Aim: The current study was designed to examine the effect of ZnO nanoparticles (ZnO –np) against the biofilm formation ability of P.aeruginosa clinical isolates and to study its effect on the expression level of the genes involved in biofilm formation and virulence factors production. Methodology: The MIC of ZnO –np against P. aeruginosa was determined by the broth microdilution method. The Effect of ZnO –np on the biofilm-forming isolates of P. aeruginosa was monitored by the microtiter plate method. P.aeruginosa isolates were tested for the expression of different biofilm and virulence genes using real-time rt-PCR. Results: ZnO –np significantly downregulated the expression level of all biofilm and virulence genes of P.aeruginosa clinical isolates except the toxA gene. Conclusions: This study demonstrates the promising use of ZnO –np as an anti-biofilm and anti-virulence compound.

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