scholarly journals Exploration for Thermostable β-Amylase of a Bacillus sp. Isolated from Compost Soil to Degrade Bacterial Biofilm

2021 ◽  
Author(s):  
Ieshita Pan
Keyword(s):  
Animal Models ◽  
Nosocomial Infections ◽  
Chronic Wounds ◽  
Bacterial Biofilm ◽  
Bacterial Biofilms ◽  
Bacillus Sp ◽  
Biomedical Devices ◽  
Urinary Catheters ◽  
Prosthetic Valves ◽  
Compost Soil

More than 85% of nosocomial infections are due to the development of bacterial biofilms. Recent research proposed that biofilm-like structures are not only visible in autopsies, biopsies, patients with chronic wounds, and exudates in animal models but are also present in biomedical devices, implants, prosthetic valves, urinary catheters, etc.

scholarly journals Confocal Laser Microscopy on Biofilms: Successes and Limitations

2008 ◽  
Vol 16 (4) ◽  
pp. 18-23 ◽  
Author(s):  
Betsey Pitts ◽  
Philip Stewart
Keyword(s):  
Cystic Fibrosis ◽  
Nosocomial Infections ◽  
Extracellular Polymeric Substances ◽  
Chronic Wounds ◽  
Confocal Laser ◽  
Bacterial Biofilms ◽  
Artificial Joint ◽  
Prosthesis Infection ◽  
Wide Range ◽  
Engineered Systems

Biofilms are communities of microbial cells and extracellular polymeric substances (EPS) attached to a surface. Bacteria exist preferentially in the biofilm state in nature and in many engineered systems. In this state, microbes tolerate antibiotics and disinfectants. Bacterial biofilms are now implicated in a wide range of human diseases and infections including cystic fibrosis, otitis media, chronic wounds, artificial joint and prosthesis infection, and many nosocomial infections. Biofilm-related infections and industrial fouling problems cost billions of dollars each year.

scholarly journals Glycoside Hydrolases Degrade Polymicrobial Bacterial Biofilms in Wounds

2016 ◽  
Vol 61 (2) ◽  
Author(s):  
Derek Fleming ◽  
Laura Chahin ◽  
Kendra Rumbaugh
Keyword(s):  
Glycoside Hydrolase ◽  
Bacterial Population ◽  
Chronic Wounds ◽  
Glycoside Hydrolases ◽  
Bacterial Biofilms ◽  
Planktonic Cells ◽  
Content Type ◽  
Biomass Dissolution

ABSTRACT The persistent nature of chronic wounds leaves them highly susceptible to invasion by a variety of pathogens that have the ability to construct an extracellular polymeric substance (EPS). This EPS makes the bacterial population, or biofilm, up to 1,000-fold more antibiotic tolerant than planktonic cells and makes wound healing extremely difficult. Thus, compounds which have the ability to degrade biofilms, but not host tissue components, are highly sought after for clinical applications. In this study, we examined the efficacy of two glycoside hydrolases, α-amylase and cellulase, which break down complex polysaccharides, to effectively disrupt Staphylococcus aureus and Pseudomonas aeruginosa monoculture and coculture biofilms. We hypothesized that glycoside hydrolase therapy would significantly reduce EPS biomass and convert bacteria to their planktonic state, leaving them more susceptible to conventional antimicrobials. Treatment of S. aureus and P. aeruginosa biofilms, grown in vitro and in vivo, with solutions of α-amylase and cellulase resulted in significant reductions in biomass, dissolution of the biofilm, and an increase in the effectiveness of subsequent antibiotic treatments. These data suggest that glycoside hydrolase therapy represents a potential safe, effective, and new avenue of treatment for biofilm-related infections.

scholarly journals Vesicle-associatedPseudomonas aeruginosaleucine aminopeptidase modulates bacterial biofilms grown on host cellular substrates

2019 ◽  
Author(s):  
Caitlin N. Esoda ◽  
Meta J. Kuehn
Keyword(s):  
Biofilm Formation ◽  
Chronic Wounds ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Bacterial Biofilm ◽  
Lung Epithelial ◽  
Coculture Model ◽  
Chronic Colonization ◽  
Bacterial Outer Membrane ◽  
Future Work

AbstractPseudomonas aeruginosa, known as one of the leading causes of morbidity and mortality in cystic fibrosis (CF) patients, secretes a variety of virulence-associated proteases. These enzymes have been shown to contribute significantly toP. aeruginosapathogenesis and biofilm formation in the chronic colonization of CF patient lungs, as well as playing a role in infections of the cornea, burn wounds and chronic wounds. Our lab has previously characterized a secretedP. aeruginosapeptidase, PaAP, that is highly expressed in chronic CF isolates. This leucine aminopeptidase is not only secreted solubly, it also associates with bacterial outer membrane vesicles (OMVs), structures known for their contribution to virulence mechanisms in a variety of Gram-negative species and one of the major components of the biofilm matrix. With this in mind, we hypothesized that PaAP may play a role inP. aeruginosabiofilm formation. Using a lung epithelial cell/bacterial biofilm coculture model, we show that PaAP deletion in a clinicalP. aeruginosabackground leads to increased early biofilm formation. We additionally found that only native vesicle-bound PaAP, as opposed to its soluble forms, could reconstitute the original PaAP-mediated inhibition phenotype, and that the PaAP-containing vesicles could disperse preformed biofilm microcolonies ofKlebsiella pneumoniae, another lung pathogen. These data provide the basis for future work into the mechanism behind PaAP-OMV mediated bacterial microcolony dispersal and the application of these findings to clinical anti-biofilm research.

scholarly journals Antimicrobial Resistance in Oral biofilm: Challenges and Alternatives

2021 ◽  
Vol 12 (1) ◽  
pp. 349-356
Author(s):  
Satish Kumar Sharma ◽  
Shmmon Ahmad
Keyword(s):  
Antimicrobial Resistance ◽  
Bacterial Infections ◽  
Molecular Mechanisms ◽  
Resistance Mechanisms ◽  
Bacterial Biofilm ◽  
Bacterial Biofilms ◽  
Target Cells ◽  
Bacterial Cells ◽  
Antimicrobial Drugs ◽  
Oral Infections

Bacterial biofilm has been a major contributor to severe bacterial infections in humans. Oral infections have also been associated with biofilm-forming microbes. Several antimicrobial strategies have been developed to combat bacterial biofilms. However, the complexity of the oral cavity has made it difficult to use common drug treatments. Most effective ways to control normal bacterial infections are rendered ineffective for bacterial biofilms. Due to limited drug concentration availability, drug neutralization or altered phenotype of bacterial cells, different drug have been ineffective to identify the target cells. This leads to the development of the multifaceted phenomenon of antimicrobial resistance (AMR). Biofilm research done so far has been focused on using antimicrobial drugs to target molecular mechanisms of cells. The severity and resistance mechanisms of extracellular matrix (ECM) have been underestimated. The present study describes different antimicrobial strategies with respect to their applications in dental or oral infections. A prospective strategy has been proposed targeting ECM which is expected to provide an insight on biofilm obstinacy and antimicrobial resistance.

scholarly journals Seasonal and Successional Influences on Bacterial Community Composition Exceed That of Protozoan Grazing in River Biofilms

2012 ◽  
Vol 78 (6) ◽  
pp. 2013-2024 ◽  
Author(s):  
Jennifer K. Wey ◽  
Klaus Jürgens ◽  
Markus Weitere
Keyword(s):  
Bacterial Community ◽  
Community Composition ◽  
Bacterial Community Composition ◽  
Bacterial Biofilm ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Bacterial Biofilms ◽  
Heterotrophic Flagellates ◽  
Operational Taxonomic Units ◽  
Protozoan Grazing

ABSTRACTThe effects of protozoa (heterotrophic flagellates and ciliates) on the morphology and community composition of bacterial biofilms were tested under natural background conditions by applying size fractionation in a river bypass system. Confocal laser scanning microscopy (CLSM) was used to monitor the morphological structure of the biofilm, and fingerprinting methods (single-stranded conformation polymorphism [SSCP] and denaturing gradient gel electrophoresis [DGGE]) were utilized to assess changes in bacterial community composition. Season and internal population dynamics had a greater influence on the bacterial biofilm than the presence of protozoa. Within this general framework, bacterial area coverage and microcolony abundance were nevertheless enhanced by the presence of ciliates (but not by the presence of flagellates). We also found that the richness of bacterial operational taxonomic units was much higher in planktonic founder communities than in the ones establishing the biofilm. Within the first 2 h of colonization of an empty substrate by bacteria, the presence of flagellates additionally altered their biofilm community composition. As the biofilms matured, the number of bacterial operational taxonomic units increased when flagellates were present in high abundances. The additional presence of ciliates tended to at first reduce (days 2 to 7) and later increase (days 14 to 29) bacterial operational taxonomic unit richness. Altogether, the response of the bacterial community to protozoan grazing pressure was small compared to that reported in planktonic studies, but our findings contradict the assumption of a general grazing resistance of bacterial biofilms toward protozoa.

scholarly journals Chronic Wounds, Biofilms and Use of Medicinal Larvae

Ulcers ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Linda J. Cowan ◽  
Joyce K. Stechmiller ◽  
Priscilla Phillips ◽  
Qingping Yang ◽  
Gregory Schultz
Keyword(s):  
Chronic Wounds ◽  
Wound Care ◽  
The United States ◽  
Bacterial Biofilms ◽  
Host Defenses ◽  
Skin Explants ◽  
Healing Wounds ◽  
Phaenicia Sericata ◽  
Significant Health

Chronic wounds are a significant health problem in the United States, with annual associated costs exceeding $20 billion annually. Traditional wound care consists of surgical debridement, manual irrigation, moisture retentive dressings, and topical and/or systemic antimicrobial therapy. However, despite progress in the science of wound healing, the prevalence and incidence of chronic wounds and their complications are escalating. The presence & complexity of bacterial biofilms in chronic wounds has recently been recognized as a key aspect of non-healing wounds. Bacterial biofilms are sessile colonies of polymicrobial organisms (bacteria, fungus, etc.) enclosed within a self-produced exopolymeric matrix that provides high levels of tolerance to host defenses, antibiotics and antiseptics. Thus, there is a need for alternative therapies to reduce biofilms in chronic wounds. In this report, we present initial findings from in vitro experiments which show that larval debridement therapy with disinfected blow fly larvae (Phaenicia sericata) reduced total CFUs (6-logs) of planktonic and mature biofilms of Pseudomonas aeruginosa or Staphylococcus aureus grown on dermal pig skin explants by 5-logs after 24 hours of exposure, and eliminated biofilms (no measurable CFUs) after 48 hours of exposure.

scholarly journals Cooperative Evolutionary Strategy between the Bacteriome and Mycobiome

mBio ◽  
2016 ◽  
Vol 7 (6) ◽  
Author(s):  
Mahmoud Ghannoum
Keyword(s):  
Biofilm Formation ◽  
Extracellular Enzymes ◽  
Chronic Wounds ◽  
Apoptotic Cell ◽  
Fungal Communities ◽  
Survival Strategies ◽  
Evolutionary Strategy ◽  
Evolutionary Strategies ◽  
Bacterial Biofilms ◽  
Microbial Dysbiosis

ABSTRACTNonhealing chronic wounds are all unique in origin and circumstance, and attempting to isolate a single etiology for the failure of a wound to heal is daunting. Wounds represent complex systems of multispecies fungal and bacterial biofilms. The survival strategies of interactive microbial communities have led to cooperative evolutionary strategies that culminate in biofilm formation. In microbial dysbiosis, biofilms are beneficial to both bacterial and fungal communities but detrimental to the host. Fungi benefit by a surge in their virulence factors, while bacteria become tolerant to antibacterials as a consequence of living under the protective umbrella of the biofilm matrix. This interkingdom cooperation negatively impacts the host, as the fungi and bacteria produce extracellular enzymes that inflict tissue damage, leading to an increase in proinflammatory cytokines, which results in oxidative damage and apoptotic cell death.

scholarly journals Microbiological Profile of Adenoid Hypertrophy Correlates to Clinical Diagnosis in Children

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Anita Szalmás ◽  
Zoltán Papp ◽  
Péter Csomor ◽  
József Kónya ◽  
István Sziklai ◽  
...  
Keyword(s):  
Otitis Media ◽  
Clinical Characteristics ◽  
Sleep Apnea Syndrome ◽  
Acute Otitis Media ◽  
Respiratory Viruses ◽  
Bacterial Biofilm ◽  
Bacterial Biofilms ◽  
Human Bocavirus ◽  
Adenoid Hypertrophy ◽  
Obstructive Sleep

Objective. Adenoid hypertrophy is a common condition in childhood, which may be associated with recurring acute otitis media (RAOM), otitis media with effusion (OME), and obstructive sleep apnea syndrome (OSAS). These different clinical characteristics have some clinical overlap; however, they might be explained by distinct immunologic and infectious profiles and result in various histopathologic findings of adenoid specimens.Methods. A total of 59 children with adenoid hypertrophy undergoing adenoidectomy were studied. Three series of identical adenoid specimens were processed to hematoxylin-eosin (H.E.) and Gram staining and to respiratory virus specific real-time PCR, respectively.Results. According to the clinical characteristics, patients were recruited into three groups: RAOM (). Bacterial biofilms were detected in 21 cases, while at least one of the studied respiratory viruses was detected in 52 specimens. RAOM cases were significantly associated with biofilm existence (). In contrast, OME group was characterized by the absence of bacterial biofilm and by normal mucosa. Showing a statistically significant correlation, all OME cases were positive for human bocavirus (HBoV, ).Conclusions. Bacterial biofilms might contribute to the damage of respiratory epithelium and recurring acute infections resulting in RAOM. In OME cases persisting respiratory viruses, mainly HBoV, can cause subsequent lymphoid hyperplasia leading to ventilation disorders and impaired immunoreactivity of the middle ear cleft.

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