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PubMed2003

Copper-induced modifications of the trophic relations in riverine algal-bacterial biofilms.

The effects of copper (Cu) on photosynthetic riverine biofilms were studied in artificial stream channels. Direct effects on the composition and functioning of the biofilms were investigated using plant pigments, community-level physiological profiles (CLPP), and pulse-amplitude-modulated (PAM) fluorescence. Copper caused a significant reduction of microalgal biomass and induced a shift in the population from diatoms to cyanobacteria. However, a decrease in biomass indicated that the replacement of species was not totally effective to counteract the toxic effects of Cu. A direct effect of Cu could also be shown in the bacterial community, and, furthermore, changes in the CLPP could be related to the Cu treatment. Copper-exposed biofilms lost the capacity to use between 11 and 15% of the substrates, but many of the remaining capacities became more robust, indicating an increased Cu tolerance due to the exposure. The change in the biofilm microbial composition points to the indirect effects of Cu on biofilms due to the close interdependence between biofilm autotrophic and heterotrophic compartments. Grazing by snails, which appeared to be an important factor structuring biofilms without any Cu addition, had a very minor effect on Cu-exposed biofilms. Although grazing changed the bacterial composition, its effects were not detected either on the algal community or on the biofilm community tolerance to Cu.

Bacteria↗
PubMed2003

Substrata effects on bacterial biofilm development in a subsurface flow dairy waste treatment wetland.

Biofilm development on two distinct rock substrata was investigated both in vitro and in a subsurface flow wastewater treatment wetland in order to determine the effect of hydrophobicity on initial bacterial adsorption, tertiary biofilm development and microbial population structure. Two commonly used wetland rock types, slag (a hydrophobic by-product of the steel smelter industry) and greywacke (a more hydrophilic sedimentary rock) were evaluated. In vitro investigations of initial microbial adsorption trends showed that the more hydrophobic slag displayed rapid bacterial adsorption rates compared to greywacke. Mean microbial adsorption rates of a mixed wetland bacterial population over 5 hours, described using a first order kinetics model, were 1.3 x 10(-12) m/sec for slag and consistently lower at 8.7 x 10(-13) m/sec for greywacke. Pristine rock studs of the two substrata were also exposed to wetland microbial communities during a six week field trial using confocal scanning laser microscopy to determine tertiary biofilm structure and fluorescent in situ hybridisation to investigate bacterial populations. During the first five weeks of growth CSLM analysis revealed that 75% of biofilms on slag were thicker and had greater coverage compared with those grown on greywacke. After six weeks of growth over 50% of the tertiary biofilms were structurally very similar on both rock types and only 25% of those grown on slag were larger than those on greywacke. In situ hybridisation analysis of bacterial populations revealed very little difference in population structure between biofilms grown on slag and those grown on greywacke. Eubacteria were present as a very high proportion of total bacteria throughout biofilm development (74.3%). The beta subgroup was the most populous of the Proteobacteria (31.4%) followed by the gamma subgroup (13.4%) and the alpha subgroup (1.3%). The results of this study suggest that slag, as a more hydrophobic substratum, promotes the initial adsorption of bacteria during early biofilm growth and better supports mature biofilm structures when used in wetlands. This study has implications for the design and construction of wastewater treatment wetlands.

Adsorption↗
PubMed2004

Growth, structure and oxygen penetration in particle supported autotrophic biofilms.

Particle supported autotrophic biofilms were cultivated in external-loop airlift reactors at two different pumice concentrations. Oxygen microelectrodes were used to investigate substrate transport and conversion. A special flow cell was designed for the measurement of oxygen concentration profiles in the particle supported biofilms under defined hydrodynamic conditions. The oxygen concentration profiles inside the biofilms were found to be steeper at high flow velocities in the bulk phase of the flow cell compared to those at low flow velocities. Furthermore, the oxygen flux increased and the thickness of the concentration boundary layer decreased with increasing flow velocity. This dependence was found to be more pronounced in less dense biofilms out of airlift reactors with lower pumice concentrations. In addition confocal laser scanning microscopy (CLSM) was used to visualize the biofilm structure. The volume fractions of bacteria and extracellular polymeric substances (lectin-specific EPS-glycoconjugates) were measured in living fully hydrated biofilms. Both the microelectrode and CLSM measurement showed the influence of shear stress on particle supported biofilms. A higher particle concentration led to dense biofilms with a homogeneous surface, lower thickness of the concentration boundary layer and steeper oxygen concentration profiles. The combination of both techniques allows a detailed and quantitative characterisation of particle associated biofilm structure and function.

Biofilms↗
PubMedDate not supplied

Evidence of bacterial biofilms in a rabbit model of sinusitis.

BACKGROUND: Bacterial biofilms have been documented on middle ear mucosa, tonsils, and cholesteatoma. In addition, we have described previously bacterial biofilms on frontal recess stents placed during surgery for chronic sinusitis. We hypothesize that bacterial biofilms are present on the mucosa of animals with sinuses experimentally infected with Pseudomonas aeruginosa. METHODS: We instilled Pseudomonas aeruginosa at log phase growth into the right maxillary sinus in 22 New Zealand white rabbits and harvested specimens 1-20 days later. We then examined the tissues with scanning electron microscopy (SEM) and light microscopy. Mucosa from the middle turbinate on the contralateral side was used as a control. RESULTS: We identified evidence of bacterial biofilms on the mucosa of all 22 animals under SEM. Twenty-one of 22 animals had sinus cultures positive for Pseudomonas. Bacterial biofilms were identified by evidence of glycocalyx, water channels, and three-dimensional structure. These images were similar to other images of known biofilms. CONCLUSION: This is evidence of the presence of bacterial biofilms in an animal model of sinusitis. This model may serve as a means to study the efficacy and safety of pharmacologic and surgical treatments on the disruption and elimination of bacterial biofilms. Additional study into the role of bacterial biofilms in perpetuating chronic sinusitis is warranted.

Animals↗
PubMed2005

Alcaligenes faecalis kw-a biofilm for denitrification of nitrate-rich effluent.

Alcaligenes faecalis kw-A selected for possessing good denitrification efficiency was used for biofilm development. The biofilm could be developed on a glass surface within 12 hr when 5%, Ix 10(8) cells/ml was used as inoculum. The microcolonies were seen in 6 hr and glycocalyx in 9 hr stage. At 24 hr the biofilm was developed fully and hence was visualised as dense mass. The biofilm protein content showed 48.5% increase in shake flask than in static condition. The exopoplymer is produced in larger amounts in biofilm as compared to the suspended cells. Also, its amount was more by 43% in the biofilm produced in shake flask condition than in static condition. The biofilm could remove 95% nitrate from nitrate-rich effluent in a bench-scale process in 36 hr. The attached growth technique demonstrated here can be utilised to study the effect of favourable as well as adverse conditions on the denitrification efficiency of a culture. The ultimate application of a denitrifying biofilm would be in attached growth or biofilm reactor.

Alcaligenes faecalis↗
PubMed2005

Influence of biofilm on removal of surrogate faecal microbes in a constructed wetland and maturation pond.

The effect of biofilm on the attenuation of pathogen-sized particles from wastewater was compared for biofilms cultivated in a surface flow constructed wetland (SFW) and maturation pond (MP) The fate of fluorescently labelled microspheres (FLM) as surrogates for viruses (0.1 microm), bacteria (1 microm) and parasitic protozoa (4.5 microm dia) was investigated in microcosms in the presence or absence of biofilms. Rates of FLM removal from suspension were higher in the presence of biofilms for all particle sizes (kd 0.02-0.11 h(-1)) in MP and SFW microcosms with removal efficiency related to particle size and biofilm thickness and structure. Greater removal of 0.1 microm (79-81%), 1 microm FLM (92-96%) and 4.5 microm FLM (up to 98%) from suspension were found for microcosms containing thicker (autotrophic) biofilms grown in the MP or open water zone of the SFW. Lower removal of 43% (0.1 microm), 59% (1 microm) and 84% (4.5 microm) occurred in microcosms containing thinner heterotrophic biofilms from SFW vegetated zones. Providing surfaces for attachment of photosynthetic biofilms offers potential to enhance pathogen removal in open water systems. In vegetated systems, linkage to more oxic openwater zones may allow thicker and 'stickier' epiphytic biofilms to develop, improving pathogen interception and removal.

Animals↗
PubMed2004

Basic features of biofilms--why are they difficult therapeutic targets?

The purpose of this paper is to review the basic features of biofilms associated with human infections and summarize why such biofilms are resistant to antimicrobial agents. The formation of most biofilms involves adherence of bacteria to a conditioned surface, growth and division of the attached bacteria, synthesis of a polymeric slime matrix, formation of a structured microbial community, and incorporation of other micro-organisms into the microbial mass. The transition of bacteria from free-floating (planktonic) to biofilm environments involves extensive up-regulation of genes associated with adherence. Micro-organisms in established biofilms engage in complex integrated activities involving activation and deactivation of genes that promote the survival of bacteria within the biofilm community. Mechanisms of the increased resistance of biofilm bacteria to antimicrobial agents may involve: (1) neutralization or consumption of the drug, (2) failure of the drug to completely penetrate the biofilm, (3) inability of the drug to affect metabolically inactive bacteria, and (4) presence of drug-resistant bacteria within biofilms.

Biofilms↗
PubMed2006

[Detection and significance of biofilm formation in yeasts isolated from hemocultures].

BACKGROUND: Yeasts of the genus Candida are important opportunistic pathogens responsible for severe bloodstream infections in immunocompromised patients. An important virulence factor that allows them to colonize plastic implants and to survive in the blood is their ability to form biofilm. The purpose of the study was to assess, how frequently this virulence factor occurred in yeasts of the genus Candida isolated from blood cultures. MATERIALS AND METHODS: Cultures of the various strains in wells of microtitre plates were used to demonstrate the presence of biofilms. In total, we tested 72 isolates of yeasts of the genus Candida from the blood culture: C. albicans (33), C. parapsilosis (19), C. tropicalis (11), C. glabrata (4), C. krusei (3), C. lipolytica (1) and C. lusitaniae (1). RESULTS: The ability to form biofilm was demonstrated in 26 strains. The largest number of biofilm-positive strains was found in C. parapsilosis (13) and C. tropicalis (7). The formation of biofilms was far less frequent in the strains of C. albicans (4). The formation of biofilms was also demonstrated in C. krusei (2) and C. glabrata (1). CONCLUSION: The increasing frequency of fungal bloodstream infections is due to the increasing use of catheters and implants. The biofilm formation in these yeasts is the chief factor of virulence promoting such infections. The demonstration of biofilm formation in an isolated strain is indicative of the probable existence of a biofilm focus and of possible difficulties during antimycotic therapy.

Biofilms↗
PubMed2001

Assessment of Changes in Biodiversity when a Community of Ultramicrobacteria Isolated from Groundwater Is Stimulated to Form a Biofilm.

The stimulation of groundwater bacteria to form biofilms, for the remediation of polluted aquifers, is subjected to environmental regulations that include measurement of effects on microbial biodiversity. Groundwater microorganisms contain a proportion of unidentified and uncharacterized ultramicrobacteria (UMB) that might play a major role in the bioclogging of geological materials. This study aimed to assess the changes in genetic and metabolic biodiversity when a community of UMB, isolated from groundwater, is stimulated to form biofilms on a ceramic surface. UMB were stimulated with aerobic conditions and injection of molasses, in reactors reproducing groundwater composition and temperature. Concentration of planktonic viable UMB, secretion of extracellular polymeric substances (EPS), and biofilm thickness were monitored. The assessment of changes in biodiversity was achieved by comparing the initial UMB community to the biofilm community, using the single strand conformational polymorphism (SSCP) method, the cloning and sequencing of 16S rRNA gene (16S rDNA) sequences, and the Biolog microplate system. The hypothesis stating that indigenous UMB would play a significant role of in the biofilm development was corroborated. Within 13 days of stimulation, the UMB produced 700 mg L?1 of planktonic EPS and formed a biofilm up to a thickness of 1100 mm. This stimulation led to a decrease in genetic diversity and an increase in metabolic diversity. The decrease in genetic diversity was shown by a reduced number of single strand DNA fragments in the SSCP profiles. As such, 16S rDNA sequences from the biofilm revealed the predominance of four bacterial groups: Zoogloea, Bacillus/Paenibacillus, Enterobacteriaceae, and Pseudomonads. A significant increase in metabolic diversity was shown by a highest substrate richness profile and a lower substrate evenness profile of the biofilm bacterial population (p = 0.0 and p = 0.09, respectively). This higher metabolic diversity might be a consequence of the stimulation that seemed to favor the growth of bacteria having a high nutritional versatility. Stimulation of UMB, isolated from groundwater, was effective to form a biofilm having a high metabolic biodiversity. This combination of molecular-based and metabolic-based methods expanded the insight into monitoring the changes in bacterial biodiversity.

Journal Article↗
PubMed2003

Kinetics of inorganic carbon utilization by microalgal biofilm in a flat plate photoreactor.

A kinetic model was developed to describe inorganic carbon utilization by microalgae biofilm in a flat plate photoreactor. The model incorporates the fundamental mechanisms of diffusive mass transport and biological reaction of inorganic carbon by microalgal biofilm. An advanced numerical technique, the orthogonal collocation method and Gear's method, was employed to solve this kinetic model. The model solutions included the concentration profiles of inorganic carbon in the microalgal biofilm, the growths of suspended microalgae and microalgal biofilm, the effluent concentrations of inorganic carbon, and the flux of inorganic carbon from bulk liquid into biofilm. The batch kinetic test was independently conducted to determine biokinetic parameters used in the microalgal biofilm model simulation while initial thickness of microalgal biofilm were assumed. A laboratory-scale flat plate photoreactor with a high recycle flow rate was setup and conducted to verify the model. The volume of photoreactor is 60 l which yields a hydraulic retention time of 1.67 days. The model-generated inorganic carbon and the suspended microalgae concentration curves agreed well with those obtained in the laboratory-scale test. The fixation efficiencies of HCO(3)(-) and CO(2) are 98.5% and 90% at a steady-state condition, respectively. The concentration of suspended microalgal cell reached up to 12 mg/l at a maximum growth rate while the thickness of microalgal biofilm was estimated to be 104 microm at a steady-state condition. The approaches of experiments and model simulation presented in this study could be employed for the design of a flat plate photoreactor to treat CO(2) by microalgal biofilm in a fossil-fuel power plant.

Air Pollutants↗
PubMedDate not supplied

Indole alkaloid formation by Catharanthus roseus cells in a biofilm reactor.

Catharanthus roseus cells producing indole alkaloids were grown in the form of a biofilm. Production medium was circulated through the reactor parallel to the upper surface of the horizontal biofilm. Sugar consumption and indole alkaloid formation were followed to compare the performance of cultures with different biofilm thicknesses. Dissolved oxygen concentrations gradients within the biofilms were determined at the end of each run. RNA and protein content of the cells in the upper and lower layers of the the biofilms were compared. Results obtained in the biofilm experiments were compared to those obtained with suspension cultures. At optimized biofilm thicknesses, the biofilm reactor was more effective than suspension cultures in maximizing indole alkaloid titers. This is thought to be due to better cell-cell contact within the biofilm and nutrient concentration gradients, which resulted in low growth rates.

Agar↗
PubMed1991

Susceptibility of Pseudomonas aeruginosa and Escherichia coli biofilms towards ciprofloxacin: effect of specific growth rate.

Methods of cell culture which enable the control of specific growth rate and expression of iron-regulated membrane proteins within Gram-negative biofilms were employed for various clinical isolates of Pseudomonas aeruginosa taken from the sputum of cystic fibrosis patients and of a laboratory strain of Escherichia coli. Susceptibility towards ciprofloxacin was assessed as a function of growth-rate for intact biofilms, cells resuspended from the biofilms and also for newly formed daughter cells shed from the biofilm during its growth and development. Patterns of susceptibility with growth rate were compared to those of suspended cultures grown in a chemostat. In all instances the susceptibility of chemostat cultures was directly related to growth rate. Whilst little difference was observed in the susceptibility pattern for P. aeruginosa strains with different observed levels of mucoidness, such populations were generally more susceptible towards ciprofloxacin than those of E. coli. At fast rates of growth P. aeruginosa cells resuspended from biofilms were significantly more resistant than chemostat grown cells. Intact P. aeruginosa biofilms were significantly more resistant than cells resuspended from them. This is in contrast to E. coli, where cells resuspended from biofilm and intact biofilms were, at the slower rates of growth, equivalent and significantly more susceptible than chemostat-grown cells. At high growth rates all methods of E. coli culture produced cells of equivalent susceptibility. For all strains, daughter cells dislodged from the biofilms demonstrated a high level of susceptibility towards ciprofloxacin which was unaffected by growth rate. This sensitivity corresponded to that of the fastest grown cells in the chemostat.

Bacteriological Techniques↗
PubMed1990

Effects of subinhibitory concentrations of vancomycin or cefamandole on biofilm production by coagulase-negative staphylococci.

The density of the biofilm layer produced on a plastic surface by 23 clinical isolates and 1 reference strain of slime-positive, coagulase-negative staphylococci was measured following growth in subinhibitory concentrations (sub-MICs) of cefamandole or vancomycin ranging from 2 to 0.008 micrograms/ml. All strains were susceptible to less than or equal to 2 micrograms of each agent per ml. The mean biofilm density produced by each strain was calculated from a total of eight determinations at each sub-MIC and was compared with the mean biofilm density of a drug-free control after correcting for differences in growth. The results showed that the density of the biofilm layer produced by 10 (42%) of 24 strains and 13 (54%) of 24 strains was significantly increased (P less than 0.006) at one or more sub-MICs of cefamandole or vancomycin, respectively. In contrast, the density of the biofilm produced by 9 (38%) of 24 and 2 (8%) of 24 strains was significantly reduced at one or more sub-MICs of cefamandole and vancomycin, respectively, and the biofilm density of 7 of these strains was decreased only when the sub-MIC was one-half the MIC. The biofilm density of six strains (five versus cefamandole and one versus vancomycin) was both enhanced and reduced by different sub-MICs of the same agent. None of the strains produced a detectable biofilm at or above the MIC for the strain. These data indicate that antimicrobial agents such as cefamandole or vancomycin could potentially enhance the biofilm matrix produced by certain slime-positive, coagulase-negative staphylococci on the surface of a biomedical implant if concentrations of these agents fall below the MIC for the infecting strain.

Cefamandole↗
PubMed1993

Interaction between biofilms formed by Pseudomonas aeruginosa and clarithromycin.

Interactions between bacterial biofilms formed by Pseudomonas aeruginosa and clarithromycin, a macrolide having no anti-P. aeruginosa activity, were investigated. P. aeruginosa incubated for 10 days on membrane filters formed biofilms on the surfaces of the filters. The biofilms were characterized by dense colonizations of bacteria and thick membranous structures that covered the colonies. Treatment of the biofilms with a relatively low concentration of clarithromycin for 5 days resulted in an eradication of the membranous structures. Quantitative analysis of alginate and hexose was done to evaluate the quantity of polysaccharides in or on the biofilms. Treatment of the biofilms with clarithromycin decreased the quantity of alginate and hexose and therefore perhaps the quantity of polysaccharides as well. Eradication of the membranous structures of biofilms, or the decrease in the quantity of polysaccharides, resulted in an increase in the rate of penetration of antibiotics through bacterial biofilms. In vivo therapeutic effects of ofloxacin in the rat infection model, in which the biofilm mode of growth of P. aeruginosa is characteristic, were enhanced by oral coadministration of clarithromycin. It is suggested that clarithromycin eradicated glycocalyx produced by P. aeruginosa, or suppressed the production of glycocalyx, by unknown mechanisms and thereby enhanced the therapeutic efficacies of other antimicrobial agents against infections caused by P. aeruginosa.

Alginates↗
PubMed1982

Method for studying microbial biofilms in flowing-water systems.

A method for the study of microbial biofilms in flowing-water systems was developed with special reference to the flow conditions in electrochemical concentration cells. Seawater was circulated in a semiclosed flow system through biofilm reactors (3 cm s) with microscope cover slips arranged in lamellar piles parallel with the flow. At fixed time intervals cover slips with their biofilm were removed from the pile, stained with crystal violet, and mounted on microscope slides. The absorbances of the slides were measured at 590 nm and plotted against time to give microbial biofilm development. From calibration experiments a staining time of 1 min and a rinse time of 10 min in a tap water flow (3 cm s) were considered sufficient. When an analysis of variance was performed on biofilm development data, 78% of the total variance was found to be due to random natural effects; the rest could be explained by experimental effects. The absorbance values correlated well with protein N, dry weight, and organic weight in two biofilm experiments, one with a biofilm with a high (75%) and one with a low ( approximately 25%, normal) inorganic content. Comparisons of regression lines revealed that the absorbance of the stained biofilms was an estimate closely related to biofilm dry weight.

Journal Article↗
PubMed1991

Growth characteristics and expression of iron-regulated outer-membrane proteins of chemostat-grown biofilm cells of Pseudomonas aeruginosa.

An in vitro chemostat system was used to study the growth and the expression of iron-regulated outer-membrane proteins (IROMPs) by biofilm cells of Pseudomonas aeruginosa cultivated under conditions of iron limitation. The population of the planktonic cells decreased when the dilution rate was increased. At a dilution rate of 0.05 h-1, the populations of planktonic cells of both mucoid and nonmucoid P. aeruginosa were 3 x 10(9) cells/mL. This value dropped to 5 x 10(6) cells/mL when the dilution rate was increased to 1.0 h-1. The reverse was observed for the biofilm cells. The number of biofilm cells colonising the silicone tubing increased when the dilution rate was increased. The number of biofilm cells of the mucoid strain at steady state was 2 x 10(8) cells/cm (length) when the dilution rate was fixed at 0.05 h-1. The figure increased to 8 x 10(9) cells/cm when the dilution rate was increased to 1.0 h-1. The population of biofilm cells of the nonmucoid strain was 9 x 10(7) cells/cm (length) when the dilution rate was 0.05 h-1. It increased to 2 x 10(9) cells/cm when the dilution rate was set at 1.0 h-1. The expression of IROMPs was induced in the biofilm cells of both mucoid and nonmucoid strains when the dilution rates were 0.05 and 0.2 h-1. IROMPs were reduced but still detectable at the dilution rate of 0.5 h-1. However, the expression of IROMPs was repressed when the dilution rate was increased to 1.0 h-1. The data suggest that the biofilm cells of P. aeruginosa switch on the expression of IROMPs to assist iron acquisition when the dilution rate used for the chemostat run is below 0.5 h-1. The high affinity iron uptake system is not required by the biofilm cells when the dilution rate is increased because the trace amount of iron present in the chemostat is sufficient for the growth of adherent biofilm cells.

Bacterial Outer Membrane Proteins↗
PubMed2026

Evaluation of sequential phage-antibiotic therapy reveals enhanced biofilm control with meropenem and colistin in clinical MDR hypervirulent Klebsiella pneumoniae strain.

AIMS: The convergence of multidrug resistance and hypervirulence in Klebsiella pneumoniae (MDR-HvKp) has narrowed treatment options. Despite growing interest in phage-antibiotic synergy, this study evaluates the underexplored combinatorial effects of phage and antibiotics, including drug-specific interactions and sequence dependency, against the biofilm-forming MDR-HvKp clinical strain. METHODS AND RESULTS: A T5-like Klebsiella bacteriophage, Round, within the genus Webervirus, was therapeutically and genomically characterized. A biofilm-forming clinical strain, Kleb_134, was used to evaluate in vitro phage-antibiotic interactions with meropenem, colistin, and tigecycline in planktonic and biofilm models.In planktonic assays, phage combinations with meropenem and colistin resulted in a multi-log CFU reduction compared to monotherapies, whereas reduced efficacy was observed with tigecycline. In biofilm assays, pre-phage treatment followed by antibiotic exposure demonstrated the strongest biofilm reduction. Drug-specific and sequence-dependent effects were evident. Meropenem-phage combinations reduced biofilm biomass by 2.85-fold (high phage titre) and 3.8-fold (low phage titre), while colistin-phage combinations achieved reductions of 8.4-fold (high phage titre) and 2.8-fold (low phage titre). CONCLUSIONS: Sequential phage-antibiotic treatment was effective against MDR-HvKp biofilms, with pre-phage exposure enhancing antibiotic access through biofilm disruption. The bacteriostatic nature of tigecycline reduced efficacy by affecting phage replication. These findings highlight the importance of treatment sequence and antibiotic selection, and extend existing knowledge in optimizing therapeutic outcomes in MDR-HvKp infections.

Biofilms↗
PubMed2025

Biofilms in clinical infection: pathophysiology, diagnosis, and the evolving therapeutic landscape.

Biofilms are structured communities of microorganisms encased in a self-produced polymeric matrix that typically adhere to surfaces. Recent research, however, has revealed that non-attached aggregates share many common traits with the surface-dependent biofilms. This mode of bacterial growth provides enhanced protection against antibiotics and resistance to host immune defenses. Biofilms require higher antibiotic concentrations than those needed to inhibit planktonic bacteria, necessitating prolonged high-dose and combination therapies to achieve effective eradication. This increased resistance is attributed to multiple factors, including the protective extracellular matrix, reduced metabolic activity of bacteria within the biofilm, and also the ability of bacterial genomes to rapidly adjust in response to environmental changes. Diagnostic modalities such as sonication, tissue culture, and polymerase chain reaction-based assays currently dominate clinical diagnostics of biofilm infections due to their practicality, cost-effectiveness, and proven reliability. Recent research has led to innovative treatment strategies that target biofilm structure, enhance drug delivery, and modulate host-pathogen interactions. This review summarizes our current knowledge of biofilm formation, explores the current techniques for detecting microbial biofilms, and discusses future perspectives for advancing diagnostic and therapeutic strategies.

Biofilms↗