scholarly journals An examination of potential differences in biofilm production among different genotypes of Pseudomonas aeruginosa

2014 ◽  
Vol 66 (1) ◽  
pp. 117-121 ◽  
Author(s):  
Zorica Vasiljevic ◽  
B. Jovcic ◽  
Ivana Cirkovic ◽  
Slobodanka Djukic
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Microtiter Plate ◽  
Band Pattern ◽  
Hospital Environment ◽  
Plate Test ◽  
Clinical Specimens ◽  
Biofilm Production

In the present study, we have examined if there is any difference in biofilm production among different genotypes of Pseudomonas aeruginosa. The study investigated 526 non-duplicate P. aeruginosa isolated from clinical specimens and from a hospital environment. Isolates were grouped into thirty-five genotypes based on an identical ERIC2-band pattern. Biofilm formation was quantified by the microtiter plate test and all strains were classified into the following categories: no biofilm producers (0), weak (+), moderate (+), or strong (+++) biofilm producers. Only 2.45% of examined strains were not biofilm producers. Among biofilm producers, 39.26% were strong biofilm producers, 34.36% were moderate biofilm producers, while 23.93% were weak biofilm producers. Although the majority of strong biofilm producers were in genotype groups 2 and 3, the degree of in vitro biofilm formation in our study was not significantly affected by the genotype of Pseudomonas aeruginosa. In this study, we demonstrated that the degree of in vitro biofilm formation is not significantly affected by the genotype of Pseudomonas aeruginosa.

scholarly journals Correlation of biofilm production with antibiotic susceptibility pattern of Pseudomonas aeruginosa from various clinical specimens

2022 ◽  
Vol 13 (1) ◽  
pp. 88-92
Author(s):  
M Swapna ◽  
G Sumathi ◽  
M Anitha
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Biofilm Formation ◽  
Antibiotic Sensitivity ◽  
Microtiter Plate ◽  
Resistance Pattern ◽  
Sensitivity Testing ◽  
Clinical Specimens ◽  
Biofilm Production ◽  
Microbiological Methods

Background: Pseudomonas aeruginosa is one of the most prevalent nosocomial pathogens that cause a life-threatening infection. One of the important characteristics of P. aeruginosa is biofilm formation which leads to antibiotic resistance. Aims and Objectives: The aim of the study was to study the antibiotic resistance pattern of P. aeruginosa isolates and correlation with their biofilm-production. Materials and Methods: A total of 87 P. aeruginosa isolates from different clinical specimens were processed and confirmed by conventional microbiological methods as per standard methodology. Antibiotic sensitivity testing was done for all isolates. Biofilm producing isolates were identified by the microtiter plate method (MTPM). Results: Of 87 P. aeruginosa isolates, majority were from pus 33 (38%), followed by urine 26 (30%), sputum 19 (22%), body fluids 7 (8%), and blood 2 (2%). Biofilm producing isolates showed more resistance in comparison to non-biofilm producers. The observed difference between biofilm formation for multidrug resistant and susceptible isolates was found to be statistically significant. Conclusion: MTPM method was an effective test for detection of biofilm formation and was also able to verify biofilm production by P. aeruginosa. This indicated a higher propensity among the clinical isolates of P. aeruginosa to form biofilm and revealed a positive correlation between biofilm formation and antibiotic resistance. This indicates the need for testing of even susceptible isolates for virulence factors such as biofilm production.

scholarly journals Biofilm Formation by Methicillin-Resistant and Methicillin-SensitiveStaphylococcus aureusStrains from Hospitalized Patients in Poland

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Małgorzata Piechota ◽  
Barbara Kot ◽  
Aneta Frankowska-Maciejewska ◽  
Agata Grużewska ◽  
Agnieszka Woźniak-Kosek
Keyword(s):  
Biofilm Formation ◽  
Negative Impact ◽  
Microtiter Plate ◽  
Hospitalized Patients ◽  
Hospital Environment ◽  
Methicillin Resistant ◽  
Biofilm Production ◽  
Bronchoalveolar Washings ◽  
Patient Health

Biofilm-mediated infections in the hospital environment have a significant negative impact on patient health. This study aimed to investigate biofilm production in vitro and the presence oficaABCDgenes in methicillin-resistantS. aureus(MRSA) and methicillin-sensitiveS. aureus(MSSA) strains isolated from hospitalized patients. MRSA (73) and MSSA (57) strains were evaluated for biofilm production by the microtiter plate method. The presence oficaoperon was investigated by PCR. Out of 130 strains, 99.2% were biofilm producers. Strong biofilms were formed by 39.7% of MRSA and 36.8% of MSSA strains. The highest percentage of strong biofilm producers was found among the strains isolated from sputum and tracheostomy tube (66.7%), nose and catheter (50%), throat (44.4%), and bronchoalveolar washings (43.8%). The strains isolated from bronchoalveolar washings produced significantly more biofilm than strains isolated from wound and anus. The ability of biofilm forming by fecal strains was significantly lower compared to strains from other materials. MRSA strains had significantly higher ability of biofilm formation than MSSA strains (P= 0.000247). The presence oficaoperon in MRSA was detected in all strains. Comparison of strong biofilm biomass of the strains withicaABCD,icaABD, andicaADrevealed that strains withicaABCDandicaABDproduced highly significantly more biofilm than strains withicaAD. Biofilm forming by both MRSA and MSSA strains indicates high ability of theses strains to persist in hospital environment which increases the risk of disease development in hospitalized patients.

scholarly journals Molecular detection of virulence factors and biofilm formation in Pseudomonas aeruginosa obtained from different clinical specimens in Bandar Abbas

2019 ◽  
Author(s):  
Nima Bahador ◽  
Saeed Shoja ◽  
Foroogh Faridi ◽  
Banafsheh Dozandeh-Mobarrez ◽  
Fatemeh Izadpanah Qeshmi ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Virulence Factors ◽  
Antimicrobial Susceptibility ◽  
Biofilm Formation ◽  
Opportunistic Pathogen ◽  
Clinical Specimens ◽  
Biofilm Production ◽  
Bandar Abbas ◽  
Susceptibility Patterns

Background and Objectives: Pseudomonas aeruginosa is a ubiquitous opportunistic pathogen. The presence of several virulence factors such as exotoxin and exoenzyme genes and biofilm may contribute to its pathogenicity. The purpose of this study was to investigate the presence of toxA, exoU and exoS, the determination of biofilm production and antimicrobial susceptibility patterns among clinical isolates of P. aeruginosa. Materials and Methods: In this study, 75 isolates of P. aeruginosa were recovered from various clinical specimens. Antimi- crobial susceptibility pattern of isolates were identified. Virulence genes toxA, exoU and exoS were determined using PCR. The ability of biofilm production was assessed. Results: Antimicrobial susceptibility test showed that 12 strains were resistant to more than 8 antibiotics (17.14%). The most effective antibiotic was colistin as 98.6% of isolates were sensitive. The frequencies of exoU and exoS genes were detected as 36.6% and 55.7%, respectively. In addition, 98.6% of the isolates were biofilm producers. Exotoxin A was detected in sixty-eight isolates (95.7%). Conclusion: The findings of this study showed that, the presence of P. aeruginosa exotoxin and exoenzyme genes, particu- larly, the exoU gene is the most common virulence factors in the bacterial isolates from urine samples. Biofilm is a serious challenge in the treatment of P. aeruginosa infection.

scholarly journals Analysis of the bacterial biofilm formation in different models of the in vitro culture

2021 ◽  
Vol 19 (1) ◽  
pp. 40-45
Author(s):  
Agnieszka Bogut ◽  
◽  
Agnieszka Magryś ◽  
Keyword(s):  
Biofilm Formation ◽  
Culture Media ◽  
Microtiter Plate ◽  
Bacterial Biofilm ◽  
Atmospheric Conditions ◽  
Experimental Conditions ◽  
Microtiter Plate Assay ◽  
Biofilm Production ◽  
Strain Type

Introduction. Microtiter plate assay (MPA) remains one of workhorses of in vitro biofilm research but it requires optimization of experimental conditions to fulfill the biofilm formation requirements of different bacterial pathogens. Aim. The aim was to determine the effect of TSB and RPMI1640 culture media and selected culture variables (O2 vs. 5% CO2, extended incubation time) on the biofilm production by bacteria commonly involved in biofilm-related infections: Enterococcus faecalis (EF), Escherichia coli (EC), Staphylococcus aureus (SA), Pseudomonas aeruginosa (PA), Klebsiella pneumoniae (KP). Material and methods. The investigation was performed using the MPA with crystal violet. Results. Statistically significant (p<0.05) increase in biofilm production between 24h and 72h time points was observed for EF (TSB o2, RPMIo2 and RPMIco2), EC (TSBo2), SA (TSBo2, TSBco2), KP (TSBo2, TSBco2), PA (RPMIco2, TSBco2). The TSB caused a significantly greater stimulation of biofilm production compared to RPM1640. It outcompeted RPMI1640 irrespective of the atmospheric conditions for SA and KP and under aerobic conditions for EF. Conclusion. Although the TSB provided the most optimal conditions for biofilm production, the process was influenced by the strain type, atmospheric conditions and period of cultivation which limits the ability to design a single universal model of the in vitro biofilm investigation.

scholarly journals Evaluation of 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyl tetrazolium bromide method for assessing biofilm formation in vitro by Trichosporon spp.

2018 ◽  
Vol 10 (04) ◽  
pp. 380-386 ◽  
Author(s):  
Thayanidhi Premamalini ◽  
Subramanian Anitha ◽  
Kanniappan Mohanapriya ◽  
Anupma Jyoti Kindo
Keyword(s):  
Mtt Assay ◽  
Biofilm Formation ◽  
Microtiter Plate ◽  
Test Tube ◽  
Tetrazolium Bromide ◽  
Biofilm Production ◽  
Invasive Infections ◽  
Polymerase Chain ◽  
Diphenyl Tetrazolium Bromide

ABSTRACT BACKGROUND: Invasive infections due to Trichosporon spp. have increased recently and are frequently associated with indwelling medical devices. Such infections which are associated with biofilm formation do not respond to the routinely used antifungal agents and are often persistent, associated with high mortality rate. Various methods have been described by researchers to evaluate and quantify the biofilm formation. AIM: This study was conducted to compare two methods of biofilm production by Trichosporon sp, i.e., test tube method with crystal violet (CV) staining and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. MATERIALS AND METHODS: Seventy-two clinical isolates of Trichosporon spp. collected from various sources were considered for the study. The identity of all the isolates was genotypically confirmed by Trichosporon-specific polymerase chain reaction (PCR). The isolates were further speciated phenotypically using biochemical profile and growth characteristics which identified the isolates as Trichosporon asahii (64/72), Trichosporon asteroides (5/72), Trichosporon cutaneum (2/72), and Trichosporon mucoides (1/72). Biofilm production was then evaluated and compared by test tube-CV method and MTT assay. RESULTS: All the Trichosporon isolates produced biofilm by MTT assay, whereas only 42 (53.6%) of the isolates were detected to be biofilm producers by CV method. Furthermore, MTT assay could differentiate better between weak and moderate biofilm producers as compared to CV method. CONCLUSION: Hence, MTT assay is a reliable method for quantification of biofilm produced by Trichosporon spp. using 96-well microtiter plate.

scholarly journals luxS Gene and Biofilm Formation in Streptococcus uberis Isolated from Bovine Mastitis Cases

2021 ◽  
Author(s):  
A.J. Greeshma ◽  
R.N. Ramani Pushpa ◽  
K. Lakshmi Kavitha ◽  
T. Srinivasa Rao
Keyword(s):  
Biofilm Formation ◽  
Bovine Mastitis ◽  
Economic Loss ◽  
Microtiter Plate ◽  
Good Choice ◽  
Luxs Gene ◽  
Biochemical Tests ◽  
Streptococcus Uberis ◽  
Biofilm Production

Background: Streptococcus uberis (S. uberis) is an environmental pathogen causing mastitis in Dairy cattle. It causes recurrent mastitis and reduction in milk production in livestock causing economic loss. The prevalence of S. uberis intramammary infections is due to ability of the organism to form biofilm in udder tissue. The present study is on in-vitro biofilm production, the correlation of luxS gene and the biofilm formation in S. uberis. Methods: A total of 91 mastitic milk samples were collected from cattle and buffaloes brought at Veterinary Hospitals and farms in Krishna, Guntur and West Godavari districts, Andhra Pradesh. The identification of the culture isolates was based on cultural and biochemical characteristics and confirmed by Polymerase Chain Reaction (PCR). The Streptococcus species cultures showing greyish, pinpointed colonies and/or aesculin hydrolysis on Edwards medium were further identified by various biochemical tests viz., catalase test, ninhydrin test, sodium hippurate hydrolysis test and type of haemolysis on 7% sheep blood agar. Confirmation of the isolates by PCR was followed by detection of biofilm formation using qualitative Congo red agar (CRA) method, quantitative microtiter plate (MTP) assay and biofilm gene (luxS) was detected using PCR.Conclusion: From this study it is suggestable that for biofilm study both phenotypic and genotypic methods should be taken together which can be influenced by various other factors also. MTP assay was a good choice for quantitative biofilm determination, which was giving a more accurate and understandable results. The results express that any of the isolates without luxS didn’t produce a strong biofilm and it is concluded that there may be other genes for regulation of biofilm production and/or luxS gene has a regulatory role for one or more genes related to biofilm formation in S. uberis.

Bioactivity of Phenolic Compounds Extracted from Strawberry against Formation of Pseudomonas aeruginosa Biofilm

2019 ◽  
Vol 10 (01) ◽  
Author(s):  
Baydaa Hussein ◽  
Zainab A. Aldhaher ◽  
Shahrazad Najem Abdu-Allah ◽  
Adel Hamdan
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Phenolic Compounds ◽  
Biofilm Formation ◽  
Opportunistic Infections ◽  
Formation Rate ◽  
Hydrocarbon Chain ◽  
Health Concern ◽  
Gas Chromatography Mass Spectrometry ◽  
Phenolic Contents

Background: Biofilm is a bacterial way of life prevalent in the world of microbes; in addition to that it is a source of alarm in the field of health concern. Pseudomonas aeruginosa is a pathogenic bacterium responsible for all opportunistic infections such as chronic and severe. Aim of this study: This paper aims to provide an overview of the promotion of isolates to produce a biofilm in vitro under special circumstances, to expose certain antibiotics to produce phenotypic evaluation of biofilm bacteria. Methods and Materials: Three diverse ways were used to inhibited biofilm formation of P.aeruginosa by effect of phenolic compounds extracts from strawberries. Isolates produced biofilm on agar MacConkey under certain circumstances. Results: The results showed that all isolates were resistant to antibiotics except sensitive to azithromycin (AZM, 15μg), and in this study was conducted on three ways to detect the biofilm produced, has been detected by the biofilm like Tissue culture plate (TCP), Tube method (TM), Congo Red Agar (CRA). These methods gave a clear result of these isolates under study. Active compounds were analyzed in both extracts by Gas Chromatography-mass Spectrometry which indicate High molecular weight compound with a long hydrocarbon chain. Conclusion: Phenolic compounds could behave as bioactive material and can be useful to be used in pharmaceutical synthesis. Phenolic contents which found in leaves and fruits extracts of strawberries shows antibacterial activity against all strains tested by the ability to reduce the production of biofilm formation rate.

scholarly journals An In Vitro Coumarin-Antibiotic Combination Treatment of Pseudomonas aeruginosa Biofilms

2021 ◽  
Vol 16 (1) ◽  
pp. 1934578X2098774
Author(s):  
Jinpeng Zou ◽  
Yang Liu ◽  
Ruiwei Guo ◽  
Yu Tang ◽  
Zhengrong Shi ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Drug Resistance ◽  
Combination Treatment ◽  
Crude Extract ◽  
Biofilm Formation ◽  
Bacterial Resistance ◽  
Antibacterial Properties ◽  
Biofilm Growth ◽  
Antibiotic Combination

The drug resistance of Pseudomonas aeruginosa is a worldwide problem due to its great threat to human health. A crude extract of Angelica dahurica has been proved to have antibacterial properties, which suggested that it may be able to inhibit the biofilm formation of P. aeruginosa; initial exploration had shown that the crude extract could inhibit the growth of P. aeruginosa effectively. After the adaptive dose of coumarin was confirmed to be a potential treatment for the bacteria’s drug resistance, “coumarin-antibiotic combination treatments” (3 coumarins—simple coumarin, imperatorin, and isoimperatorin—combined with 2 antibiotics—ampicillin and ceftazidime) were examined to determine their capability to inhibit P. aeruginosa. The final results showed that (1) coumarin with either ampicillin or ceftazidime significantly inhibited the biofilm formation of P. aeruginosa; (2) coumarin could directly destroy mature biofilms; and (3) the combination treatment can synergistically enhance the inhibition of biofilm formation, which could significantly reduce the usage of antibiotics and bacterial resistance. To sum up, a coumarin-antibiotic combination treatment may be a potential way to inhibit the biofilm growth of P. aeruginosa and provides a reference for antibiotic resistance treatment.

scholarly journals Antibiofilm and antivirulence potential of silver nanoparticles against multidrug-resistant Acinetobacter baumannii

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Helal F. Hetta ◽  
Israa M. S. Al-Kadmy ◽  
Saba Saadoon Khazaal ◽  
Suhad Abbas ◽  
Ahmed Suhail ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Microtiter Plate ◽  
Diffusion Method ◽  
Resistance Pattern ◽  
Infection Model ◽  
The Impact

AbstractWe aimed to isolate Acinetobacter baumannii (A. baumannii) from wound infections, determine their resistance and virulence profile, and assess the impact of Silver nanoparticles (AgNPs) on the bacterial growth, virulence and biofilm-related gene expression. AgNPs were synthesized and characterized using TEM, XRD and FTIR spectroscopy. A. baumannii (n = 200) were isolated and identified. Resistance pattern was determined and virulence genes (afa/draBC, cnf1, cnf2, csgA, cvaC, fimH, fyuA, ibeA, iutA, kpsMT II, PAI, papC, PapG II, III, sfa/focDE and traT) were screened using PCR. Biofilm formation was evaluated using Microtiter plate method. Then, the antimicrobial activity of AgNPs was evaluated by the well-diffusion method, growth kinetics and MIC determination. Inhibition of biofilm formation and the ability to disperse biofilms in exposure to AgNPs were evaluated. The effect of AgNPs on the expression of virulence and biofilm-related genes (bap, OmpA, abaI, csuA/B, A1S_2091, A1S_1510, A1S_0690, A1S_0114) were estimated using QRT-PCR. In vitro infection model for analyzing the antibacterial activity of AgNPs was done using a co-culture infection model of A. baumannii with human fibroblast skin cell line HFF-1 or Vero cell lines. A. baumannii had high level of resistance to antibiotics. Most of the isolates harbored the fimH, afa/draBC, cnf1, csgA and cnf2, and the majority of A. baumannii produced strong biofilms. AgNPs inhibited the growth of A. baumannii efficiently with MIC ranging from 4 to 25 µg/ml. A. baumannii showed a reduced growth rate in the presence of AgNPs. The inhibitory activity and the anti-biofilm activity of AgNPs were more pronounced against the weak biofilm producers. Moreover, AgNPs decreased the expression of kpsMII , afa/draBC,bap, OmpA, and csuA/B genes. The in vitro infection model revealed a significant antibacterial activity of AgNPs against extracellular and intracellular A. baumannii. AgNPs highly interrupted bacterial multiplication and biofilm formation. AgNPs downregulated the transcription level of important virulence and biofilm-related genes. Our findings provide an additional step towards understanding the mechanisms by which sliver nanoparticles interfere with the microbial spread and persistence.

Evaluation of the Role of Staphylococci in the Pathomechanism of Conjunctivitis

2021 ◽  
Author(s):  
Ewa Jasińska ◽  
Agnieszka Bogut ◽  
Agnieszka Magryś ◽  
Alina Olender
Keyword(s):  
Antibiotic Resistance ◽  
Epithelial Cells ◽  
Biofilm Formation ◽  
Methicillin Resistance ◽  
Microtiter Plate ◽  
Host Cells ◽  
Diffusion Method ◽  
Microtiter Plate Assay ◽  
Low Prevalence

Abstract Purpose: Determination of the association between ica genes and phenotypic biofilm formation in staphylococcal isolates involved in conjunctivitis, their antibiotic resistance as well as detection of selected virulence characteristics: adhesion to epithelial cells and in vitro cytotoxicity.Methods: The study included 26 Staphylococcus aureus (SA) and 26 Staphylococcus epidermidis (SE) isolates. The presence of icaAD genes and ica operon was determined by the PCR assay. Phenotypic biofilm formation was verified using the microtiter plate assay. Antibiotic resistance was performed using the disc diffusion method. Staphylococcal ability to attach to host cells was assessed by flow cytometry. Cytotoxicity on epithelial cells was evaluated by LDH assay.Results: The ica genes were detected in 26.9% of SE and in 42.3% of SA isolates. Only 15.3% of isolates (SE) were positive for both the icaAD and the ica operon. Phenotypically, 19.2% of SE isolates were strong biofilm producers, among which three were both icaAD- and ica operon-positive. 26.9% of SA isolates were strong biofilm producers. Methicillin resistance (MR) was detected in 34.6% of SE and 26.9% of SA isolates. 75% of MR isolates were multidrug resistant. SA isolates adhered to host cells more extensively than SE. SA isolates released higher level of LDH than SE.Conclusions: Adherence abilities were commonly observed in staphylococci associated with conjunctivitis. However, low prevalence of isolates positive for a complete and functional ica locus and low prevalence of strong biofilm producers was detected. SA adhered to a greater extent to eukaryotic cells than SE and were more cytotoxic.

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