scholarly journals Study on biofilm-forming properties of clinical isolates of Staphylococcus aureus

2011 ◽  
Vol 6 (05) ◽  
pp. 403-409 ◽  
Author(s):  
Yasmeen Taj ◽  
Farhan Essa ◽  
Faisal Aziz ◽  
Shahana Urooj Kazmi
Keyword(s):  
Electron Microscopy ◽  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Assay Method ◽  
Scanning Electron Micrographs ◽  
Clinical Specimens ◽  
Biofilm Production ◽  
Important Virulence Factor ◽  
Air Liquid Interface ◽  
Scanning Electron

Introduction: The purpose of this study was to observe the formation of biofilm, an important virulence factor, by isolates of Staphylococcus aureus (S. aureus) in Pakistan by different conventional methods and through electron microscopy. Methodology: We screened 115 strains of S. aureus isolated from different clinical specimens by tube method (TM), air-liquid interface coverslip assay method, Congo red agar (CRA) method, and scanning electron microscopy (SEM). Results: Out of 115 S. aureus isolates, 63 (54.78%) showed biofilm formation by tube method. Biofilm forming bacteria were further categorized as high producers (n = 23, 20%) and moderate producers (n = 40, 34.78%). TM coordinated well with the coverslip assay for strong biofilm-producing strains in 19 (16.5%) isolates. By coverslip method, weak producers were difficult to differentiate from biofilm negative isolates. Screening on CRA showed biofilm formation only in four (3.47%) strains. Scanning electron micrographs showed the biofilm-forming strains of S. aureus arranged in a matrix on the propylene surface and correlated well with the TM. Conclusion: Biofilm production is a marker of virulence for clinically relevant staphylococcal infections. It can be studied by various methods but screening on CRA is not recommended for investigation of biofilm formation in Staphylococcus aureus. Electron micrograph images correlate well with the biofilm production as observed by TM. 

scholarly journals Diclofenac May Induce PIA-Independent Biofilm Formation in Staphylococcus aureus Strains

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Agostinho Alves de Lima e Silva ◽  
Alice Slotfeldt Viana ◽  
Priscila Martins Silva ◽  
Eduardo de Matos Nogueira ◽  
Leonardo Tavares Salgado ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Staphylococcus Aureus ◽  
Minimum Inhibitory Concentration ◽  
Biofilm Formation ◽  
Inhibitory Concentration ◽  
Multiresistant Pathogens ◽  
Biofilm Production ◽  
Polysaccharide Intercellular Adhesion ◽  
Scanning Electron

Staphylococcus aureus is a pathogen commonly resistant to antibiotics. Biofilm formation is one of the important factors related to its virulence. Non-antibiotics drugs, such as nonsteroidal anti-inflammatory agents (NSAIDs), have been studied as an alternative for treating infections by multiresistant pathogens and biofilm-associated infections. In this study, the effects of NSAID sodium diclofenac on growth inhibition and biofilm formation of S. aureus were evaluated. The minimum inhibitory concentration (MIC) of diclofenac for fifty isolates ranged from 200 to 400 μg/mL. Diclofenac sub-MICs induced biofilm in 32.3% of biofilm-negative strains in tryptic soy broth. All biofilms induced by the drug showed a PIA- (polysaccharide intercellular adhesion-) independent composition, and the scanning electron microscopy showed that the induced biofilm presented a very discrete matrix. The combination of diclofenac with rifampicin sub-MICs induced strong production of PIA-dependent biofilm in three of four strains, while combination of NSAID with NaCl induced the formation of partially polysaccharide biofilm in two strains and PIA-independent biofilm in another strain. The combination of NSAID with glucose resulted in PIA-independent biofilms in all four strains tested. The results showed that diclofenac can commonly induce biofilm production by a PIA-independent pathway. However, when this NSAID is combined with other types of inducing agents, the composition of the biofilm produced may vary.

Biological Evaluation of Selected 1,2,3-triazole Derivatives as Antibacterial and Antibiofilm Agents

2020 ◽  
Vol 20 (24) ◽  
pp. 2186-2191
Author(s):  
Lialyz Soares Pereira André ◽  
Renata Freire Alves Pereira ◽  
Felipe Ramos Pinheiro ◽  
Aislan Cristina Rheder Fagundes Pascoal ◽  
Vitor Francisco Ferreira ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Public Health Problem ◽  
Biological Evaluation ◽  
Major Public Health Problem ◽  
Community Environments ◽  
Scanning Electron

Background: Resistance to antimicrobial agents is a major public health problem, being Staphylococcus aureus prevalent in infections in hospital and community environments and, admittedly, related to biofilm formation in biotic and abiotic surfaces. Biofilms form a complex and structured community of microorganisms surrounded by an extracellular matrix adhering to each other and to a surface that gives them even more protection from and resistance against the action of antimicrobial agents, as well as against host defenses. Methods: Aiming to control and solve these problems, our study sought to evaluate the action of 1,2,3- triazoles against a Staphylococcus aureus isolate in planktonic and in the biofilm form, evaluating the activity of this triazole through Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) tests. We have also performed cytotoxic evaluation and Scanning Electron Microscopy (SEM) of the biofilms under the treatment of the compound. The 1,2,3-triazole DAN 49 showed bacteriostatic and bactericidal activity (MIC and MBC 128 μg/mL). In addition, its presence interfered with the biofilm formation stage (1/2 MIC, p <0.000001) and demonstrated an effect on young preformed biofilm (2 MICs, p <0.05). Results: Scanning Electron Microscopy images showed a reduction in the cell population and the appearance of deformations on the surface of some bacteria in the biofilm under treatment with the compound. Conclusion: Therefore, it was possible to conclude the promising anti-biofilm potential of 1,2,3-triazole, demonstrating the importance of the synthesis of new compounds with biological activity.

scholarly journals Biofilm Formation and its Association with Antibiotic Susceptibility Pattern in Methicillin-resistant Staphylococcus aureus isolates

2021 ◽  
Author(s):  
Bajarangi Lal Chaudhary ◽  
Dakshina Bisht ◽  
Sameer Singh Faujdar
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Antibiotic Sensitivity ◽  
Diffusion Method ◽  
Beta Lactamase ◽  
Isolation And Identification ◽  
Methicillin Resistant ◽  
Clinical Specimens ◽  
Biofilm Production

Methicillin-resistant Staphylococcus aureus is a clinically significant pathogen that causes infections ranging from skin and soft tissue infections to life-threatening sepsis. Biofilm formation by MRSA is one of the crucial virulence factor. Determination of beta-lactamase and biofilm production among Staphylococcus aureus was obtained from various clinical specimens. Standard bacteriological procedures were used for isolation and identification and antibiotic sensitivity was determined using the Kirby Bauer disc diffusion method according to CLSI guidelines. The cloverleaf method, acidometric, iodometric and chromogenic methods were used to detect beta-lactamase while the microtiter plate method and Congo red agar method were used to detect biofilm production. Of the 288 MRSA strains isolated from various clinical specimens,198 (67.07%) were biofilm producers. Cloverleaf and chromogenic (nitrocefin) disc shows 100% results for beta-lactamase detection. Vancomycin was 100% sensitive followed by teicoplanin (92.36%) and linezolid (89.93%). Cloverleaf and nitrocefin disc methods were the most sensitive for detection of beta-lactamase in S. aureus and there was no significant relation between biofilm production and antibiotic sensitivity pattern of S. aureus.

scholarly journals Inhibitory Effects of 1,2,3,4,6-Penta-O-Galloyl-β-d-Glucopyranose on Biofilm Formation byStaphylococcus aureus

2010 ◽  
Vol 55 (3) ◽  
pp. 1021-1027 ◽  
Author(s):  
Mei-Hui Lin ◽  
Fang-Rong Chang ◽  
Mu-Yi Hua ◽  
Yang-Chang Wu ◽  
Shih-Tung Liu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Fibroblast Cells ◽  
Clinical Use ◽  
Polysaccharide Intercellular Adhesin ◽  
Inhibitory Effects ◽  
Initial Attachment ◽  
Scanning Electron

ABSTRACT1,2,3,4,6-Penta-O-galloyl-β-d-glucopyranose (PGG) is an active ingredient in plants that are commonly used in Chinese medicine to treat inflammation. We demonstrate here that PGG, at 6.25 μM, does not inhibit the growth ofStaphylococcus aureus, and yet it prevents biofilm formation on polystyrene and polycarbonate surfaces. At the same concentration, PGG is not toxic to human epithelial and fibroblast cells. PGG has an IB50value, i.e., the PGG concentration that inhibits 50% biofilm formation, of 3.6 μM. The value is substantially lower than that ofN-acetylcysteine, iodoacetamide, andN-phenyl maleimide, which are known to inhibit biofilm formation byS. aureus. Biochemical and scanning electron microscopy results also reveal that PGG inhibits initial attachment of the bacteria to solid surface and the synthesis of polysaccharide intercellular adhesin, explaining how PGG inhibits biofilm formation. The results of this study demonstrate that coating PGG on polystyrene and silicon rubber surfaces with polyaniline prevents biofilm formation, indicating that PGG is highly promising for clinical use in preventing biofilm formation byS. aureus.

scholarly journals Staphylococcal Biofilm on the Surface of Catheters: Electron Microscopy Evaluation of the Inhibition of Biofilm Growth by RNAIII Inhibiting Peptide

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 879
Author(s):  
Adilson de Oliveira ◽  
Luiza Pinheiro-Hubinger ◽  
Valéria Cataneli Pereira ◽  
Danilo Flávio Moraes Riboli ◽  
Katheryne Benini Martins ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Biofilm Formation ◽  
Aureus Strain ◽  
Coagulase Negative Staphylococci ◽  
Biofilm Growth ◽  
Promising Tool ◽  
Biofilm Production ◽  
Causative Agents ◽  
Scanning Electron

Staphylococcus aureus and coagulase-negative staphylococci (CoNS) have become the main causative agents of medical device-related infections due to their biofilm-forming capability, which protects them from the host’s immune system and from the action of antimicrobials. This study evaluated the ability of RNA III inhibiting peptide (RIP) to inhibit biofilm formation in 10 strains isolated from clinical materials, including one S. aureus strain, two S. epidermidis, two S. haemolyticus, two S. lugdunensis, and one isolate each of the following species: S. warneri, S. hominis, and S. saprophyticus. The isolates were selected from a total of 200 strains evaluated regarding phenotypic biofilm production and the presence and expression of the ica operon. The isolates were cultured in trypticase soy broth with 2% glucose in 96-well polystyrene plates containing catheter segments in the presence and absence of RIP. The catheter segments were observed by scanning electron microscopy. The results showed inhibition of biofilm formation in the presence of RIP in all CoNS isolates; however, RIP did not interfere with biofilm formation by S. aureus. RIP is a promising tool that might be used in the future for the prevention of biofilm-related infections caused by CoNS.

scholarly journals Scanning electron microscopy of biofilm formation by Staphylococcus aureus on stainless steel and polypropylene surfaces

2014 ◽  
Vol 8 (34) ◽  
pp. 3136-3143
Author(s):  
Alessandra P. Sant’Anna Salimena ◽  
◽  
Alexandre C. Santos ◽  
Maria das Graças Cardoso ◽  
Eduardo Alves ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Staphylococcus Aureus ◽  
Stainless Steel ◽  
Biofilm Formation ◽  
Scanning Electron

Use of electron microscopy to characterize the surfaces of flocculent and nonflocculent yeast cells

1989 ◽  
Vol 35 (12) ◽  
pp. 1081-1086 ◽  
Author(s):  
Byron F. Johnson ◽  
L. C. Sowden ◽  
Teena Walker ◽  
Bong Y. Yoo ◽  
Gode B. Calleja
Keyword(s):  
Electron Microscopy ◽  
Fission Yeast ◽  
Budding Yeast ◽  
The Other ◽  
Yeast Cells ◽  
Scanning Electron Micrographs ◽  
Soft Or ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Scanning Electron

The surfaces of flocculent and nonflocculent yeast cells have been examined by electron microscopy. Nonextractive preparative procedures for scanning electron microscopy allow comparison in which sharp or softened images of surface details (scars, etc.) are the criteria for relative abundance of flocculum material. Asexually flocculent budding-yeast cells cannot be distinguished from nonflocculent budding-yeast cells in scanning electron micrographs because the scar details of both are well resolved, being hard and sharp. On the other hand, flocculent fission-yeast cells are readily distinguished from nonflocculent cells because fission scars are mostly soft or obscured on flocculent cells, but sharp on nonflocculent cells. Sexually and asexually flocculent fission-yeast cells cannot be distinguished from one another as both are heavily clad in "mucilaginous" or "hairy" coverings. Examination of lightly extracted and heavily extracted flocculent fission-yeast cells by transmission electron microscopy provides micrographs consistent with the scanning electron micrographs.Key words: flocculation, budding yeast, fission yeast, scanning, transmission.

scholarly journals Apolar Bioactive Fraction ofMelipona scutellarisGeopropolis onStreptococcus mutansBiofilm

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Marcos Guilherme da Cunha ◽  
Marcelo Franchin ◽  
Lívia Câmara de Carvalho Galvão ◽  
Bruno Bueno-Silva ◽  
Masaharu Ikegaki ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Biofilm Formation ◽  
Microbial Population ◽  
Ethanolic Extract ◽  
Vehicle Control ◽  
Sem Images ◽  
Killing Assay ◽  
Bioactive Fraction ◽  
Biofilm Matrix ◽  
Scanning Electron

The aim of this study was to evaluate the influence of the bioactive nonpolar fraction of geopropolis onStreptococcus mutansbiofilm. The ethanolic extract ofMelipona scutellarisgeopropolis was subjected to a liquid-liquid partition, thus obtaining the bioactive hexane fraction (HF) possessing antimicrobial activity. The effects of HF onS. mutansUA159 biofilms generated on saliva-coated hydroxyapatite discs were analyzed by inhibition of formation, killing assay, and glycolytic pH-drop assays. Furthermore, biofilms treated with vehicle control and HF were analyzed by scanning electron microscopy (SEM). HF at 250 μg/mL and 400 μg/mL caused 38% and 53% reduction in the biomass of biofilm, respectively, when compared to vehicle control (P<0.05) subsequently observed at SEM images, and this reduction was noticed in the amounts of extracellular alkali-soluble glucans, intracellular iodophilic polysaccharides, and proteins. In addition, theS. mutansviability (killing assay) and acid production by glycolytic pH drop were not affected (P>0.05). In conclusion, the bioactive HF of geopropolis was promising to control theS. mutansbiofilm formation, without affecting the microbial population but interfering with its structure by reducing the biochemical content of biofilm matrix.

scholarly journals ANTIBIOGRAM PROFILE AND BIOFILM FORMING POTENTIAL OF PSEUDOMONAS SPECIES ISOLATED FROM VARIOUS CLINICAL SPECIMENS

2018 ◽  
Vol 11 (10) ◽  
pp. 150
Author(s):  
Jamsheera Cp ◽  
Ethel Suman
Keyword(s):  
Biofilm Formation ◽  
Susceptibility Testing ◽  
Diffusion Method ◽  
Resistance Pattern ◽  
Chi Square ◽  
Clinical Specimens ◽  
Medical College ◽  
Biofilm Production ◽  
Pseudomonas Species ◽  
Chi Square Test

Objective: The present study aimed at finding the resistance pattern of Pseudomonas aeruginosa and other Pseudomonas species isolated from various clinical specimens in the laboratory.Methods: A total of 150 isolates of different species of Pseudomonas obtained from various clinical specimens processed at the Microbiology laboratory of Kasturba Medical College, Manipal Academy of Higher Education, were taken for this study. Antibiotic susceptibility testing was performed by Kirby-Bauer disc diffusion method and interpreted according to the CLSI guidelines. Biofilm assay was performed by modified O’Toole and Kolter method. The results were analyzed using SPSS 17.0 and Student’s unpaired t-test, Kruskal–Wallis, Mann–Whitney, ANOVA, and Chi-square test. p<0.05 was considered statistically significant.Results: Increased resistance was observed by P. aeruginosa to cefotaxime, cotrimoxazole, levofloxacin, ofloxacin, and ticarcillin clavulanate. There was also a good correlation between antibiotic resistance to aztreonam, netilmicin, and ceftazidime and biofilm production. Results of the present study, therefore, demonstrated the occurrence of resistance to various antipseudomonal agents among the biofilm-producing P. aeruginosa isolates.Conclusion: The present study may help in assessing the seriousness of drug resistance caused by biofilm formation in P. aeruginosa and devise strategies through antibiotic policies to minimize such problems.

scholarly journals Molecular Investigation of Fibronectin-Binding Protein Genes and Capacity of Biofilm Production in Staphylococcus Aureus Isolated From Clinical Samples

2021 ◽  
Author(s):  
Hossein Jafari Soghondicolaei ◽  
Mohammad Ahanjan ◽  
Mehrdad Gholami ◽  
Bahman Mirzaei ◽  
Hamid Reza Goli
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Colorimetric Assay ◽  
Binding Protein ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Biofilm Production ◽  
Fibronectin Binding Protein ◽  
Fibronectin Binding

Abstract Biofilm production increases Staphylococcus aureus resistance to antibiotics and also host defense mechanisms. The current study aims to evaluate the biofilm formation by S. aureus and to determine the prevalence of fibronectin-binding protein genes, also its correlation with drug resistance. In this study, 100 clinical isolates of S. aureus were collected. The antibiotic susceptibility pattern of the isolates was evaluated by the disk agar diffusion method. The ability of biofilm formation in the studied isolates was also determined by microplate colorimetric assay. Then, all isolates were screened by polymerase chain reaction for the fnbA and fnbB genes. Out of 100 clinical isolates of S. aureus, the highest and lowest antibiotic resistance rates were against penicillin (94%) and vancomycin (6%). Thirty-two cases were found to be multi-drug resistant (MDR) among the all strains. The ability of biofilm production was observed in 89% of the isolates. The PCR results showed that the prevalence of fnbA and fnbB genes were 91% and 17%, respectively. Moreover, 100% and 21.8% of the MDR strains harbored the fnbA and fnbB genes respectively. The ability to form biofilm in MDR isolates of S. aureus is more than non-MDR isolates, especially fnbA positive ones. As the bacteria in the biofilm are difficult to kill by antibiotics, attention to the removal or control of the biofilm production seems to be necessary.

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