Mechanisms of Biofilm Development, Antibiotic Resistance and Tolerance and Their Role in Persistent Infections

2019 ◽  
pp. 115-130
Author(s):  
Divya Srivastava ◽  
Suchi Srivastava ◽  
Poonam C. Singh ◽  
Adesh Kumar
Keyword(s):  
Antibiotic Resistance ◽  
Persistent Infections ◽  
Biofilm Development

scholarly journals In Vitro Evaluation of Gentamicin or Vancomycin Containing Bone Graft Substitute in the Prevention of Orthopedic Implant-Related Infections

2020 ◽  
Vol 21 (23) ◽  
pp. 9250
Author(s):  
Alessandro Bidossi ◽  
Marta Bottagisio ◽  
Nicola Logoluso ◽  
Elena De Vecchi
Keyword(s):  
Antibiotic Resistance ◽  
Bone Graft ◽  
Calcium Sulfate ◽  
Prolonged Exposure ◽  
Bacterial Colonization ◽  
Bone Graft Substitute ◽  
Bacterial Strains ◽  
Bone Graft Substitutes ◽  
Biofilm Development

Antibiotic-loaded bone graft substitutes are attractive clinical options and have been used for years either for prophylaxis or therapy for periprosthetic and fracture-related infections. Calcium sulfate and hydroxyapatite can be combined in an injectable and moldable bone graft substitute that provides dead space management with local release of high concentrations of antibiotics in a one-stage approach. With the aim to test preventive strategies against bone infections, a commercial hydroxyapatite/calcium sulfate bone graft substitute containing either gentamicin or vancomycin was tested against Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa, harboring different resistance determinants. The prevention of bacterial colonization and biofilm development by selected microorganisms was investigated along with the capability of the eluted antibiotics to select for antibiotic resistance. The addition of antibiotics drastically affected the ability of the selected strains to adhere to the tested compound. Furthermore, both the antibiotics eluted by the bone graft substitutes were able to negatively impair the biofilm maturation of all the staphylococcal strains. As expected, P. aeruginosa was significantly affected only by the gentamicin containing bone graft substitutes. Finally, the prolonged exposure to antibiotic-containing sulfate/hydroxyapatite discs did not lead to any stable or transient adaptations in either of the tested bacterial strains. No signs of the development of antibiotic resistance were found, which confirms the safety of this strategy for the prevention of infection in orthopedic surgery.

scholarly journals Characterization of Temporal Protein Production in Pseudomonas aeruginosa Biofilms

2005 ◽  
Vol 187 (23) ◽  
pp. 8114-8126 ◽  
Author(s):  
Christopher J. Southey-Pillig ◽  
David G. Davies ◽  
Karin Sauer
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Biofilm Formation ◽  
Protein Production ◽  
Developmental Stages ◽  
Developmental Process ◽  
Developmental Cycle ◽  
Specific Proteins ◽  
Biofilm Development ◽  
The Impact

ABSTRACT Phenotypic and genetic evidence supporting the notion of biofilm formation as a developmental process is growing. In the present work, we provide additional support for this hypothesis by identifying the onset of accumulation of biofilm-stage specific proteins during Pseudomonas aeruginosa biofilm maturation and by tracking the abundance of these proteins in planktonic and three biofilm developmental stages. The onset of protein production was found to correlate with the progression of biofilms in developmental stages. Protein identification revealed that proteins with similar function grouped within similar protein abundance patterns. Metabolic and housekeeping proteins were found to group within a pattern separate from virulence, antibiotic resistance, and quorum-sensing-related proteins. The latter were produced in a progressive manner, indicating that attendant features that are characteristic of biofilms such as antibiotic resistance and virulence may be part of the biofilm developmental process. Mutations in genes for selected proteins from several protein production patterns were made, and the impact of these mutations on biofilm development was evaluated. The proteins cytochrome c oxidase, a probable chemotaxis transducer, a two-component response regulator, and MexH were produced only in mature and late-stage biofilms. Mutations in the genes encoding these proteins did not confer defects in growth, initial attachment, early biofilm formation, or twitching motility but were observed to arrest biofilm development at the stage of cell cluster formation we call the maturation-1 stage. The results indicated that expression of theses genes was required for the progression of biofilms into three-dimensional structures on abiotic surfaces and the completion of the biofilm developmental cycle. Reverse transcription-PCR analysis confirmed the detectable change in expression of the respective genes ccoO, PA4101, and PA4208. We propose a possible mechanism for the role of these biofilm-specific proteins in biofilm formation.

AyigPmutant strain is a small colony variant ofE. coliand shows pleiotropic antibiotic resistance

2017 ◽  
Vol 63 (12) ◽  
pp. 961-969 ◽  
Author(s):  
Hui Xia ◽  
Qiongwei Tang ◽  
Jie Song ◽  
Jiang Ye ◽  
Haizhen Wu ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Genetic Basis ◽  
Coenzyme Q ◽  
Small Colony Variant ◽  
E Coli ◽  
Collateral Sensitivity ◽  
Persistent Infections ◽  
Antibiotic Resistance Profile ◽  
Small Colony ◽  
Insight Into

Small colony variants (SCVs) are a commonly observed subpopulation of bacteria that have a small colony size and distinctive biochemical characteristics. SCVs are more resistant than the wild type to some antibiotics and usually cause persistent infections in the clinic. SCV studies have been very active during the past 2 decades, especially Staphylococcus aureus SCVs. However, fewer studies on Escherichia coli SCVs exist, so we studied an E. coli SCV during an experiment involving the deletion of the yigP locus. PCR and DNA sequencing revealed that the SCV was attributable to a defect in the yigP function. Furthermore, we investigated the antibiotic resistance profile of the E. coli SCV and it showed increased erythromycin, kanamycin, and d-cycloserine resistance, but collateral sensitivity to ampicillin, polymyxin, chloramphenicol, tetracycline, rifampin, and nalidixic acid. We tried to determine the association between yigP and the pleiotropic antibiotic resistance of the SCV by analyzing biofilm formation, cellular morphology, and coenzyme Q (Q8) production. Our results indicated that impaired Q8biosynthesis was the primary factor that contributed to the increased resistance and collateral sensitivity of the SCV. This study offers a novel genetic basis for E. coli SCVs and an insight into the development of alternative antimicrobial strategies for clinical therapy.

scholarly journals Peering into the matrix: A look at biofilms and their inherent antibiotic resistance

SURG Journal ◽  
2013 ◽  
Vol 6 (2) ◽  
pp. 71-77
Author(s):  
Kevin J. Stinson
Keyword(s):  
Antibiotic Resistance ◽  
Phenotypic Variation ◽  
Extracellular Polymeric Substances ◽  
Resistance Mechanisms ◽  
Host Immune System ◽  
Bacterial Cells ◽  
Relative Significance ◽  
Adaptive Resistance ◽  
Persistent Infections ◽  
The Matrix

Biofilms are increasingly being regarded as the predominant form of bacterial growth in natural settings. These structures consist of bacterial cells immobilized at a surface and encased in a self-produced matrix of extracellular polymeric substances. In clinical settings, biofilms are the cause of persistent infections that are difficult to clear through the action of the host immune system. Biofilm-encased cells are also associated with increased levels of antibiotic resistance compared to their planktonic counterparts. The result is increased morbidity and mortality when biofilms are associated with disease. In this review, the focus of discussion will be the various mechanisms of antibiotic resistance common to biofilms and the role these mechanisms play in the pathogenesis of major clinically-relevant microorganisms. Antibiotic penetration, altered microenvironments, phenotypic variation, and adaptive resistance mechanisms are all key players in the development of antibiotic resistance in bacterial biofilms. Though the relative significance of each individual mechanism varies, when combined they confer extensive protection to the biofilm’s cellular populations. Keywords: biofilms; antibiotic resistance (mechanisms of); clinical applications; disease; antibiotic penetration; altered microenvironments; phenotypic variation; adaptive resistance; review

scholarly journals eDNA Inactivation and Biofilm Inhibition by the Polymeric Biocide Polyhexamethylene Guanidine Hydrochloride (PHMG-Cl)

2022 ◽  
Vol 23 (2) ◽  
pp. 731
Author(s):  
Olena V. Moshynets ◽  
Taras P. Baranovskyi ◽  
Olga S. Iungin ◽  
Nadiia P. Kysil ◽  
Larysa O. Metelytsia ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Gene Transfer ◽  
Resistance Gene ◽  
Antibiotic Resistance Gene ◽  
Guanidine Hydrochloride ◽  
Dust Particles ◽  
Biofilm Inhibition ◽  
Water Contaminants ◽  
Polyhexamethylene Guanidine ◽  
Biofilm Development

The choice of effective biocides used for routine hospital practice should consider the role of disinfectants in the maintenance and development of local resistome and how they might affect antibiotic resistance gene transfer within the hospital microbial population. Currently, there is little understanding of how different biocides contribute to eDNA release that may contribute to gene transfer and subsequent environmental retention. Here, we investigated how different biocides affect the release of eDNA from mature biofilms of two opportunistic model strains Pseudomonas aeruginosa ATCC 27853 (PA) and Staphylococcus aureus ATCC 25923 (SA) and contribute to the hospital resistome in the form of surface and water contaminants and dust particles. The effect of four groups of biocides, alcohols, hydrogen peroxide, quaternary ammonium compounds, and the polymeric biocide polyhexamethylene guanidine hydrochloride (PHMG-Cl), was evaluated using PA and SA biofilms. Most biocides, except for PHMG-Cl and 70% ethanol, caused substantial eDNA release, and PHMG-Cl was found to block biofilm development when used at concentrations of 0.5% and 0.1%. This might be associated with the formation of DNA–PHMG-Cl complexes as PHMG-Cl is predicted to bind to AT base pairs by molecular docking assays. PHMG-Cl was found to bind high-molecular DNA and plasmid DNA and continued to inactivate DNA on surfaces even after 4 weeks. PHMG-Cl also effectively inactivated biofilm-associated antibiotic resistance gene eDNA released by a pan-drug-resistant Klebsiella strain, which demonstrates the potential of a polymeric biocide as a new surface-active agent to combat the spread of antibiotic resistance in hospital settings.

scholarly journals Systematic Inactivation and Phenotypic Characterization of Two-Component Signal Transduction Systems of Enterococcus faecalis V583

2004 ◽  
Vol 186 (23) ◽  
pp. 7951-7958 ◽  
Author(s):  
Lynn E. Hancock ◽  
Marta Perego
Keyword(s):  
Signal Transduction ◽  
Antibiotic Resistance ◽  
Environmental Stress ◽  
Enterococcus Faecalis ◽  
Response Regulator ◽  
Phenotypic Characterization ◽  
Response Regulators ◽  
Two Component ◽  
Two Component Signal Transduction ◽  
Biofilm Development

ABSTRACT The ability of enterococci to adapt and respond to different environmental stimuli, including the host environment, led us to investigate the role of two-component signal transduction in the regulation of Enterococcus faecalis physiology. Using a bioinformatic approach, we previously identified 17 two-component systems (TCS), consisting of a sensory histidine kinase and the cognate response regulator, as well as an additional orphan response regulator (L. E. Hancock and M. Perego, J. Bacteriol. 184:5819-5825, 2002). In an effort to identify the potential function of each TCS in the biology of E. faecalis clinical isolate strain V583, we constructed insertion mutations in each of the response regulators. We were able to inactivate 17 of 18 response regulators, the exception being an ortholog of YycF, previously shown to be essential for viability in a variety of gram-positive microorganisms. The biological effects of the remaining mutations were assessed by using a number of assays, including antibiotic resistance, biofilm formation, and environmental stress. We identified TCS related to antibiotic resistance and environmental stress and found one system which controls the initiation of biofilm development by E. faecalis.

scholarly journals Induction of Multidrug Resistance Mechanism in Escherichia coli Biofilms by Interplay between Tetracycline and Ampicillin Resistance Genes

2009 ◽  
Vol 53 (11) ◽  
pp. 4628-4639 ◽  
Author(s):  
Thithiwat May ◽  
Akinobu Ito ◽  
Satoshi Okabe
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antimicrobial Agents ◽  
Efflux Pump ◽  
Marker Genes ◽  
Ampicillin Resistance ◽  
High Level ◽  
Biofilm Development ◽  
Level Resistance

ABSTRACT Biofilms gain resistance to various antimicrobial agents, and the presence of antibiotic resistance genes is thought to contribute to a biofilm-mediated antibiotic resistance. Here we showed the interplay between the tetracycline resistance efflux pump TetA(C) and the ampicillin resistance gene (bla TEM-1) in biofilms of Escherichia coli harboring pBR322 in the presence of the mixture of ampicillin and tetracycline. E. coli in the biofilms could obtain the high-level resistance to ampicillin, tetracycline, penicillin, erythromycin, and chloramphenicol during biofilm development and maturation as a result of the interplay between the marker genes on the plasmids, the increase of plasmid copy number, and consequently the induction of the efflux systems on the bacterial chromosome, especially the EmrY/K and EvgA/S pumps. In addition, we characterized the overexpression of the TetA(C) pump that contributed to osmotic stress response and was involved in the induction of capsular colanic acid production, promoting formation of mature biofilms. However, this investigated phenomenon was highly dependent on the addition of the subinhibitory concentrations of antibiotic mixture, and the biofilm resistance behavior was limited to aminoglycoside antibiotics. Thus, marker genes on plasmids played an important role in both resistance of biofilm cells to antibiotics and in formation of mature biofilms, as they could trigger specific chromosomal resistance mechanisms to confer a high-level resistance during biofilm formation.

scholarly journals Inhibition of MreB and ftsZ proteins to minimize E. coli biofilms formation

2019 ◽  
Author(s):  
Emile Charles
Keyword(s):  
United States ◽  
Antibiotic Resistance ◽  
Cell Division ◽  
Mortality Rate ◽  
Cell Shape ◽  
The United States ◽  
Resistant Bacteria ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Biofilm Development

AbstractIn the United States, more than two million individuals become infected by antibiotic-resistant bacteria, resulting in over 23,000 deaths annually. Bacterial biofilms, one of the major causes of this resistance, form a complex extracellular matrix that physically block antibiotic treatment. Within planktonic bacteria, two proteins, MreB and ftsZ, play a key role in bacterial cell growth and development. MreB regulates this development through maintaining the rod-like shape of gram-negative bacteria, while ftsZ regulates the timing and location of cell division. The present study compared the effects of two protein-inhibitors on biofilm formation of E. coli; the inhibitors, A22 Hydrochloride and PC190723, inhibit MreB (cell shape) and ftsZ (cell division), respectively. Efficacy was measured with a crystal violet staining assay. Four experiments were designed testing 1) the minimum inhibitory concentration of the inhibitors, 2) the synergistic effect of the inhibitors, 3) the microscopic effects of the inhibitors, and 4) the effect of the inhibitors on antibiotic susceptibility. A mid-level dosage of A22 significantly decreased biofilm density while there was no response to PC190732. The effect of A22 was verified microscopically, observing the change from bacilli cells to coccoid ones via the inhibition of MreB. In the second experiment, with conjunct inhibition, no interaction was found. Lastly, A22 was as effective as Amoxicillin in disrupting biofilms. The inhibition of MreB was found to have a key role in biofilm development. A model is proposed for biofilm density based on cell shape as affected by MreB.ImportanceEach year, more than 2 million Americans acquire antibiotic-resistant infection and 23,000 of them die (CDC, 2013). In a study done by Barsoumian et. al (2015), there was a 16% mortality rate pertaining to biofilm-related infections while non-biofilm infection caused a 5% mortality rate. These casualties aren’t limited to the United States. Abroad, antibiotic resistance is a huge issue: 25,000 deaths estimated in the EU; 38,000 deaths in Thailand; and 58,000 deaths in India, among infants alone (CDC, 2012). It is these statistics that inform us that antibiotic resistance must be addressed.

scholarly journals eDNA Inactivation and Biofilm Inhibition by the Polymeric Biocide Polyhexamethylene Guanidine Hydrochloride (PHMG-Cl)

2021 ◽  
Author(s):  
Olena V. Moshynets ◽  
Taras P. Baranovskyi ◽  
Olga S. Iungin ◽  
Nadiia P. Kysil ◽  
Larysa O. Metelytsia ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Gene Transfer ◽  
Resistance Gene ◽  
Antibiotic Resistance Gene ◽  
Guanidine Hydrochloride ◽  
Active Agent ◽  
Dust Particles ◽  
Biofilm Inhibition ◽  
Water Contaminants ◽  
Biofilm Development

The choice of effective biocides used for routine hospital practice should consider the role of disinfectants in the maintenance and development of local resistome and how they might affect antibiotic resistance gene transfer within the hospital microbial population. Currently, there is little understanding of how different biocides contribute to eDNA release that may contribute to gene transfer and subsequent environmental retention. Here we investigated how different biocides affected the release of eDNA from mature biofilms of two opportunistic model strains Pseudomonas aeruginosa ATCC 27853 (PA) and Staphylococcus aureus ATCC 25923 (SA) and contribute to the hospital resistome in the form of surface and water contaminants and dust particles. The effect of four groups of biocides including alcohols, hydrogen peroxide, quaternary ammonium compounds, and polymeric guanidines were evaluated using PA and SA biofilms. Most biocides, except for PHMG-Cl and 70% ethanol, caused substantial eDNA release and PHMG-Cl was found to block biofilm development when used at concentrations of 0.5% and 0.1%. This might be associated with the formation of DNA-PHMG-Cl complexes as PHMG-Cl is predicted to bind to AT base pairs by molecular docking assays. PHMG-Cl was found to bind high molecular DNA and plasmid DNA and continued to inactivate DNA on surfaces even after four weeks. PHMG-Cl also effectively inactivated biofilm-associated antibiotic resistance gene eDNA released by a pan-drug-resistant Klebsiella strain which demonstrates the potential of PHMG-Cl as a new surface-active agent to combat the spread of antibiotic resistance in hospital settings.

scholarly journals Role ofepaQ, a Previously UncharacterizedEnterococcus faecalisGene, in Biofilm Development and Antimicrobial Resistance

2019 ◽  
Vol 201 (18) ◽  
Author(s):  
Michelle L. Korir ◽  
Jennifer L. Dale ◽  
Gary M. Dunny
Keyword(s):  
Antibiotic Resistance ◽  
Biofilm Formation ◽  
Cell Surface Hydrophobicity ◽  
Opportunistic Pathogen ◽  
Surface Hydrophobicity ◽  
Biofilm Growth ◽  
Content Type ◽  
Biofilm Architecture ◽  
High Level ◽  
Biofilm Development

ABSTRACTEnterococcus faecalisis a commensal of the human gastrointestinal tract; it is also an opportunistic pathogen and one of the leading causes of hospital-acquired infections.E. faecalisproduces biofilms that are highly resistant to antibiotics, and it has been previously reported that certain genes of theepaoperon contribute to biofilm-associated antibiotic resistance. Despite several studies examining theepaoperon, many gene products of this operon remain annotated as hypothetical proteins. Here, we further explore theepaoperon; we identifiedepaQ, currently annotated as encoding a hypothetical membrane protein, as being important for biofilm formation in the presence of the antibiotic daptomycin. Mutants with disruptions ofepaQwere more susceptible to daptomycin relative to the wild type, suggesting its importance in biofilm-associated antibiotic resistance. Furthermore, the ΔepaQmutant exhibited an altered biofilm architectural arrangement and formed small aggregates in liquid cultures. Our cumulative data show thatepamutations result in altered polysaccharide content, increased cell surface hydrophobicity, and decreased membrane potential. Surprisingly, severalepamutations significantly increased resistance to the antibiotic ceftriaxone, indicating that the way in which theepaoperon impacts antibiotic resistance is antibiotic dependent. These results further define the key role ofepain antibiotic resistance in biofilms and in biofilm architecture.IMPORTANCEE. faecalisis a common cause of nosocomial infection, has a high level of antibiotic resistance, and forms robust biofilms. Biofilm formation is associated with increased antibiotic resistance. Therefore, a thorough understanding of biofilm-associated antibiotic resistance is important for combating resistance. Several genes from theepaoperon have previously been implicated in biofilm-associated antibiotic resistance, pathogenesis, and competitive fitness in the GI tract, but most genes in this locus remain uncharacterized. Here, we examineepaQ,which has not been characterized functionally. We show that the ΔepaQmutant exhibits reduced biofilm formation in the presence of daptomycin, altered biofilm architecture, and increased resistance to ceftriaxone, further expanding our understanding of the contribution of this operon to intrinsic enterococcal antibiotic resistance and biofilm growth.

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