Biofilm Formation of Staphylococcus aureus Isolated from Infected Wound (original) (raw)
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Research in Molecular Medicine
Background: The nosocomial infections that cause the establishment of biofilms on the embedded biomedical surfaces are the leading cause of sepsis and are often related to colonization of implants by Staphylococcus epidermidis. Materials and Methods: A total of 40 clinical S. aureus isolates were collected from Zabol, Iran. The ability of these strains to form biofilm was determined by microliter tissue culture plates. All clinical isolates were tested for the presence of icaA and icaD genes by Polymerase Chain Reaction (PCR). Results: The outcome of this study showed that from 40 isolates of Staphylococcus aureus, 12 (30%) of them were contained icaA gene and 8 (20%) isolates were positive for icaD gene and five (12.5%) isolates were contained both genes. Conclusion: The capability of S. aureus clinical isolates to form biofilm is different/diverse. This may be caused by the differences in the containing of biofilm-related genes, genetic make-up and physiological situation.
Biofilm Formation by Staphylococcus aureus Isolates from Skin and Soft Tissue Infections
Current Microbiology, 2015
Many diseases caused by Staphylococcus aureus are associated with biofilm formation. However, the ability of S. aureus isolates from skin and soft tissue infections to form biofilms has not yet been investigated. We tested 160 isolates from patients with various skin infections for biofilm-forming capacity in different growth media. All the isolates formed biofilms, the extent of which depended on the type of growth medium. The thickest biofilms were formed when both plasma and glucose were present in the broth; in this case, S. aureus incorporated host fibrin into the biofilm's matrix. There were no differences in the biofilm formation between isolates from different types of skin infections, except for a particularly good biofilm formation by isolates from diabetic wounds and a weaker biofilm formation by isolates from impetigo. In conclusion, biofilm formation is a universal behavior of S. aureus isolates from skin infections. In some cases, such as in diabetic wounds, a particularly strong biofilm formation most likely contributes to the chronic and recurrent character of the infection. Additionally, as S. aureus apparently uses host fibrin as part of the biofilm structure, we suggest that plasma should be included more frequently in in vitro biofilm studies.
The new microbiologica, 2010
Biofilm formation is the leading cause of the pathogenesis of S. aureus associated with biomaterial infections. In S. aureus polysaccharide intercellular adhesin (PIA) was encoded by icaA and icaD genes. Production of PIA is currently responsible for staphylococcal biofilm development. In this study, S. aureus strains isolated from auricular infection (n = 46) and S. aureus ATCC 25923 were phenotyped and genotyped. Slime production was assessed using Congo red agar plate assay. In order to determine the biofilm formation capacity at various pH levels of the studied S. aureus strains, microtiter plate assay was performed. The strains were grown in medium adjusted at various pH levels (3, 5, 7, 9 and 12) and medium supplemented with hydrogen peroxide 3% (v/v). Qualitative biofilm production of S. aureus revealed that 56.5% of strains were slime producers. In addition 78.26% of strains were icaA and icaD positive. Quantitative biofilm showed that biofilm production depended on the pH v...
Evaluation of Biofilm Formation in Staphylococcus aureus Clinical Isolates
medicallaboratory journal, 2019
Background and Objectives: Staphylococcus aureus is a common cause of nosocomial infections. The ability of S. aureus to form biofilm and acquire antimicrobial resistance has made this organism a major health problem. In this study, we investigate the biofilm-forming ability of S. aureus isolates from clinical samples. Methods: Sixty S. aureus isolates from clinical specimens were collected from the 5th Azar Hospital of Gorgan (Iran) in 2018. The isolates were identified using conventional methods including Gram staining and biochemical tests (catalase and coagulase). Biofilm formation by S. aureus isolates was evaluated using a microplate-based method. Results: Of 60 S. aureus isolates, 47 (78.3%) strains were identified as biofilmforming and 13 (21.7%) strains were non-biofilm-forming. Conclusion: The high prevalence of biofilm-producing S. aureus isolates in the 5 th Azar hospital of Gorgan could pose a major health challenge with serious consequences for hospitalized patients. Therefore, it is crucial to disinfect and sterilize hospital surfaces and equipment effectively to minimize the risk of contamination and spread of bacteria in the hospital settings.
ijph.jo.research.ac.ir
Wound infections are a common cause of staphylococcal infections. An ability of S.aureus is to adhere and form biofilm on host surfaces. Biofilm is an exopolysaccharide, a slime matrix around multiple layers of cells and is mediated by expression of the icaADBC operon. The present study evaluated the biofilm forming capacity and the presence of icaAD gene among S.aureus isolated from wound infections. Slime production assay was performed by cultivation on Congo Red Agar plate. In addition, Quantitative biofilm formation determined by microtiter plate assay PCR method used for detection of icaAD gene. Fifty strains were identified, 54% of the isolates produced black colonies on CRA plate, 52% were positive biofilm forming, and all strains carried the icaAD gene. Regarding the ability of S.aureus to form biofilms helps the bacterium to survive hostile environments within the host, suggests that biofilm production is a risk factor for infection. It is important in rapid diagnosis and treatment biofilm forming strains, because biofilm formation may lead to increased antimicrobial resistance and create a significant impediment to wound healing.
Evaluation of different detection methods of biofilm formation in Staphylococcus aureus
Medical Microbiology and Immunology, 2002
The icaADBC gene locus of Staphylococcus aureus and its polysaccharide intercellular adhesin (PIA/ PNSG) were recently identified, but biofilm formation has rarely been detected in vitro. In this study we evaluated a tissue culture plate (TCP) assay and a tube test, as well as Congo red agar, using the two basic media trypticase soy broth (TSB) and brain heart infusion (BHI) broth with different sugar supplements for detection of biofilm formation in 128 ica-positive S. aureus isolates. Of the S. aureus strains, 57.1% displayed a biofilm-positive phenotype under optimized conditions in the TCP test. The tube test correlated well with the TCP test for strongly biofilm-producing strains, whereas weak producers were not safely discriminated from biofilm-negative strains. Screening on Congo red agar displayed a strong correlation with the TCP and the tube test for only 3.8%, and is therefore not recommended for investigation of biofilm formation in S. aureus.
DESCRIPTION Aim: To conduct a comparative analysis of the impact of WBP treatment methods on the capacity of S. aureus isolated from chronic wounds to form biofilms in vitro. Methods: We modeled S. aureus biofilm formation in 96-well plates. We assayed the capacity of bacteria isolated from chronic wounds to form biofilms at the time of patient admission and after treatment with either ultrasound debridement (UD) and topical negative pressure (TNP; Main Group) or standard dressings (Control Group). We also compared biofilm formation by bacteria from patients with different grafting outcomes. Results: The treatment of chronic wounds with UD and TNP reduced the capacity of S. aureus to synthesise a major biofilm substance. S. aureus iso- lates from patients with favourable skin-grafting results had a lower capacity to form biofilms in vitro compared with isolates from patients with poor skin-grafting results. The use of UD and TNP for surgical closure reduced the length of the skin-gr...
2016
Biofilms are group of microorganisms encased in a matrix of extracellular polysaccharide (slime), called polysaccharide intercellular adhesin (PIA). They have been associated with a variety of chronic and persistent infections. Staphylococcus aureus is from bacteria which have high ability to form a biofilm. In this study, detection of biofilm production by Staphylococcus aureus was done by using three different methods: tube method (TM), congo red agar method (CRA) and tissue culture plate method (TCP), three repetitions were made for every method. Among of 117 strains of Staphylococcus spp isolated between October 2015 and January 2016 at the University Hospital Ibn Rochd in Casablanca, 74 were identified as Staphylococcus aureus. 58 isolates were detected as biofilm producer by TCP method, 49 by TM and 42 by CRA method. We can conclude from our study that the TCP method is a more quantitative and reliable method for the detection of biofilm formation by Staphylococcus aureus as c...
Detection of biofilm-forming genes in Staphylococcus aureus clinical isolates by PCR assay
Detection of biofilm-forming genes in Staphylococcus aureus clinical isolates by PCR assay, 2022
Biofilms are assemblages of bacteria encased in an extracellular matrix, as well as proteins, exopolysaccharides and macromolecules such as DNA. Bacterial biofilms are thought to play a substantial influence in over 80% of bacterial illnesses. Biofilm buildup on medical implants is responsible for about 60% of hospital-acquired infections. In this study, 150 clinical samples (wound, urine and sputum) were collected from patients admitted to surgical wards of Azadi teaching hospital/Kirkuk during the period from February to October 2018. Of these, 98 (65.3%) were females and 52 (34.7%) were males. Congo Red Agar was used to test the potential of S. aureus isolates to produce biofilms. The relationship between S. aureus biofilm producer isolates and ica ABCD operon genes was studied by using PCR. Out of all samples, S. aureus isolates were identified in 29 (19.3%) of clinical samples, and most isolates were from wound infections (n=19, 65.5%) followed by urine (n=10, 43.5%). Whereas, no S. aureus isolate was detected in sputum samples. Moreover, S. aureus biofilm producing isolates were detected in 9 (24.1%) samples and were represented as black colonies on Congo Red Agar. The results of this study indicated the icaA, icaB, icaC and icaD genes harbored in 4 (44.4%) of S. aureus biofilm forming isolates while icaA, icaC, and icaD genes were detected in 6 (66.7%) of isolates. On the other hand, all S. aureus isolates were negative for both clfB and fnbB genes.
2016
Purpose: The purpose of this study was to determine the rate of biofilm production by S.aureus and S.epidermidis isolated from different clinical specimens. Methods: Quantitation of biofilm formation by staphylococci was carried out using three in vitro methods namely tissue culture plate (TCP), tube method (TM), and congo red agar (CRA) method. Results: Out of 237 (94.8%) S.aureus isolates tested, 25 strains were found to form biofilm, out of these one (0.42%) was strong biofilm producer and 24 (10.12%) were moderate biofilm producers. In TM and CRA method 20 (8.43%) and 10 (4.2%) strains were moderate biofilm producers, rest were considered as weak or non-biofilm producers. All the 25 biofilm positive strains were S.aureus. Conclusion: The TCP method is more sensitive to detect biofilm formation by S.aureus when compare to tube method (TM), and congo red agar (CRA) method.