Wastewater composition often fluctuates in both toxicity and turbidity, making fixed operating conditions in hybrid Advanced Oxidation Processes (AOP) - biological systems prone to either unnecessary energy use or biological upset. Here, we present a sensor-guided, self-optimizing photocatalytic-biological treatment framework for cost-effective operation under time-varying conditions. The Bio-Photocatalytic Reactor integrates a UV-LED- driven photocatalytic module with an encapsulated biological module, enabling simultaneous treatment while physically protecting the biomass from direct UV irradiation and short-lived reactive oxygen species. Ciprofloxacin and humic acid were used as model toxic and turbidity-causing contaminants, respectively. We quantified a strong turbidity-dependent loss of photocatalytic performance above ∼100 NTU whereas the biological module substantially reduced turbidity while retaining activity after encapsulation. To enable adaptive control, an online resazurin-based toxicity sensor and a turbidity probe were integrated as in-situ state measurements. These signals were used in a feedback-controlled algorithm that dynamically adjusted UV intensity and retention time, thus regulating the toxicity of the outlet stream to meet a preset value while constantly aiming at reducing operational costs, taking into account an experimentally-derived operating-cost function. The system was tested successfully under step changes in inlet toxicity at low turbidity, and under step changes in turbidity at a constant high toxicity. This work establishes a proof of concept for closed-loop, self-optimizing hybrid AOP-biological treatment and provides a control framework that can be extended to other photoactivated-biological wastewater treatment configurations.

Background Plant associated microbiomes, encompassing diverse microbial communities underpin plant health, stress adaptation, and agricultural productivity, but can also serve as environmental reservoirs of antibiotic resistance genes (ARGs). These bacterial communities and associated ARGs span the plant-soil-food interface that is central to One Health concept. Although many studies have characterized established plant microbiomes and resistomes, the mechanisms driving their initial formations and temporal dynamics remain poorly understood. Results We employed a germfree lettuce ( Lactuca sativa ) (GL) model to investigate core bacteria and ARGs in leaves, roots, and soils in early microbial populations subjected to tetracycline (TET) pressure and exposure to the enteric pathogen Salmonella enterica serotype Typhimurium. Our results showed that initial bacterial loads and temporal dynamics were the primary determinants of microbiome and resistome structures, independent of Salmonella inoculation of leaves, whereas TET exerted only transient and early selection. Burkholderiaceae and Pseudomonadaceae were the key early colonizers but persisted over time and dominated the roots and soils. These core bacteria were also the major hosts of multidrug resistance (MDR) determinants, particularly efflux pumps. Mex-pump family members remained abundant in the resistomes across all time points, whereas TET family of ARGs contributed minimally to the resistome. Notably, no antibiotic resistant Salmonella isolates were recovered from lettuce leaves, suggesting limited selective pressure in the phyllosphere. Germfree models offer the advantage of manipulating the early colonizers, providing valuable insights into the role of specific microbes in the formation of new resistomes. Therefore, our GL model can offer valuable insights into the role of specific microbes in the formation of new resistomes. Conclusions Our findings indicate that intrinsic MDR efflux systems constitute the backbone of plant resistomes and that priority effects and time outweigh antibiotic selection in directing resistome trajectories. Framed within One Health, our results suggest that interventions targeting early community assembly may be as consequential as reducing antibiotic inputs for limiting ARG propagation across agricultural ecosystems and downstream to food chains. The germfree plant platform offers a tractable testbed to evaluate mitigation strategies that align agricultural practice with One Health goals.

Over the past five decades, at least 18 major Salmonella outbreaks have been associated with chocolate products. Contamination of chocolate may occur at various stages, from raw material handling to processing and packaging. Due to its high fat content and low water activity, chocolate provides a protective environment for Salmonella at elevated temperatures, posing considerable health risks. Although strict hygiene protocols are implemented in dry production environments, effective cleaning, especially of chocolate transfer pipelines, remains a significant challenge. This study investigated the efficacy of palm olein oil (POo) as a sanitizing agent against Salmonella on surfaces typical of chocolate production lines. Steel coupons were either directly inoculated with a cocktail of four Salmonella serotypes or coated with contaminated chocolate. After a 24 h acclimation period, the coupons were immersed in POo at 20 °C and 92 °C, and bacterial survival was assessed. Immersion in POo at 92 °C resulted in greater than 5-log reduction of Salmonella within 24 h. However, residual cells were detected on the coupons, with complete elimination observed after 7 days. At 20 °C, a 2.5-log reduction was achieved on chocolate-coated surfaces after 7 days, and viable cells were detected in the oil, highlighting a potential risk of cross-contamination through oil recirculation. No significant reduction occurred on surfaces contaminated directly with bacteria at 20 °C. These findings suggest that one-step treatments with hot POo offer practical food-grade and effective methods for killing Salmonella on surfaces of processing equipment, therefore may support in-house validation of cleaning protocols in high-fat, low-moisture food manufacturing settings.

Conventional point-of-care lateral flow immunoassays are characterized by an antibody-tagged probe irregular coupling that can limit sensitivity and require a long assay's time. We synthesized polyethylene glycol-modified selenium nanoparticles (PEG-SeNPs) by template method and developed a strategy to set antibody probes targeted and orderly by using PEG-SeNPs. Synthesized PEG-SeNPs with high stability could immobilize antibodies in the "stand-up" orientation, resulting in a faster detection time of less than 1 min by direct observer visualization without instruments or equipment. Results showed that SARS-CoV-2 antibody could be systematically structured on the chip, resulting in a detection limit of 10 pg/mL, significantly higher than conventional chips. The new device has been validated on 192 clinical samples and we found 100% negative coincidence, 93.94% positive coincidence, and 95.83% overall coincidence with reverse transcriptional PCR test. The orderly arrayed probe's stability allowed to detect throat swabs, saliva, serum, fingertip blood samples, and mutant strains without cross-reactivity with common respiratory viruses or pathogenic strains, demonstrating promising potential for a universal colorimetric platform for ultrafast field-deployable diagnostics.

Lettuce has been commonly associated with the contamination of human pathogens, such as Escherichia coli O157:H7 (hereafter O157:H7), which has resulted in serious foodborne illnesses. Contamination events may happen throughout the farm-to-fork chain, when O157:H7 colonizes edible tissues and closely interacts with the plant. Environmental conditions have a significant impact on many plant-microbe interactions; however, it is currently unknown whether temperature affects O157:H7 colonization of the lettuce phyllosphere. In this study, we investigated the relationship between elevated growth temperatures, O157:H7 persistence, and lettuce head growth using 25 lettuce genotypes. Plants were grown under optimal or elevated temperatures for 3.5 weeks before being inoculated with O157:H7. The bacterial population size in the phyllosphere and lettuce head area was estimated at 0- and 10-days postinoculation (DPI) to assess bacterial persistence and head growth during contamination. We found that growing temperature can have a positive, negative, or no effect on O157:H7 persistence depending on the lettuce genotype. Furthermore, temperature had a greater effect on head area size than the presence of O157:H7. The results suggested that the combination of plant genotype and temperature level is an important factor for O157:H7 colonization of lettuce and the possibility to combine desirable food safety traits with heat tolerance into the lettuce germplasm.

Salmonella enterica is a leading human pathogen responsible for foodborne outbreaks worldwide. In the last decade, foods with low water activity (a(w)) and high-fat content have been involved in an increased occurrence of foodborne outbreaks. This research focuses on the foodstuff tahini, which is often linked to Salmonella infection outbreaks and recalls. Thermal treatments are suggested to reduce microbial populations in tahini, but little is known about its effectiveness against Salmonella. Our major objectives were to study the survival of Salmonella Typhimurium in tahini treated at temperatures >= 70 degrees C, and to identify food related factors that could influence its survival. Based on our experimental results the thermal treatments at 70 degrees C, 80 degrees C and 90 degrees C are suitable to inactivate only a partial population of Salmonella. The death of Salmonella in tahini matches a biphasic logarithmic inactivation model, with a maximal 3-log reduction after 1 h at 90 degrees C. Moreover, we observed that a second thermal treatment the day after the first treatment, is significantly less effective compared with the first thermal treatment. The inactivation rates of Salmonella in 100% tahini are almost 4-log lower than in water/tahini emulsions at 70 degrees C, with negative linear correlation between D-value and a(w), and the Salmonella susceptibility to heat in sesame oil/tahini emulsions is affected by the matrix of pre-acclimation. Bacteria that had been acclimated in tahini kept their heat resistance, while acclimation in sesame oil before mixing in the preheated oil/tahini emulsions resulted in a sharp decline within 2 min at 70 degrees C. According to these findings, tahini producers' current pasteurization processes are not sufficient to achieve the required 5-log reduction. Furthermore, we suggest that due to the tahini heterogenicity, the a(w) in the micro-environment of each bacterium, which is shaped by the tahini substances, plays an essential role in Salmonella's survival in tahini at temperatures >= 70 degrees C.

Salmonella enterica is one of the most common human pathogens associated with fresh produce outbreaks. The present study suggests that expression of BcsZ, one of the proteins in the bcs complex, enhances the survival of Salmonella Typhimurium on parsley. BcsZ demonstrated glucanase activity with the substrates carboxymethylcellulose and crystalline cellulose, and was responsible for a major part of the S. Typhimurium CMCase activity. Moreover, there was constitutive expression of BcsZ, which was also manifested after exposure to plant polysaccharides and parsley-leaf extract. In an in-planta model, overexpression of BcsZ significantly improved the epiphytic and endophytic survival of S. Typhimurium on/in parsley leaves compared with the wild-type strain and bcsZ null mutant. Interestingly, necrotic lesions appeared on the parsley leaf after infiltration of Salmonella overexpressing BcsZ, while infiltration of the wild-type S. Typhimurium did not cause any visible symptoms. Infiltration of purified BcsZ enzyme, or its degradation products also caused symptoms on parsley leaves. We suggest that the BcsZ degradation products trigger the plant’s defense response, causing local necrotic symptoms. These results indicate that BcsZ plays an important role in the Salmonella-plant interactions, and imply that injured bacteria may take part in these interactions.

Binding functional biomolecules to non-biological materials, such as single-walled carbon nanotubes (SWNTs), is a challenging task with relevance for different applications. However, no one has yet undertaken a comparison of the binding of SWNTs to different recombinant filamentous viruses (phages) bioengineered to contain different binding peptides fused to the virus coat proteins. This is important due to the range of possible binding efficiencies and scenarios that may arise when the protein's amino acid sequence is modified, since the peptides may alter the virus's biological properties or they may behave differently when they are in the context of being displayed on the virus coat protein; in addition, non-engineered viruses may non-specifically adsorb to SWNTs. To test these possibilities, we used four recombinant phage templates and the wild type. In the first circumstance, we observed different binding capabilities and biological functional alterations; e.g., some peptides, in the context of viral templates, did not bind to SWNTs, although it was proven that the bare peptide did. The second circumstance was excluded, as the wild-type virus was found to hardly bind to the SWNTs. These results may be relevant to the possible use of the virus as a "SWNT shuttle" in nano-scale self-assembly, particularly since the pIII proteins are free to act as binding-directing agents. Therefore, knowledge of the differences between and efficiencies of SWNT binding templates may help in choosing better binding phages or peptides for possible future applications and industrial mass production.

Wastewater streams contain a large number of contaminants, part of which can be quite toxic for the working bacteria in bioreactors, thus hampering its efficiency. In such cases, pretreatment by an Advanced Oxidation Process (AOP) might be needed. Since, in general, biotreatment is more economic than AOP, it is sensible to design the integrated system in a manner that would reduce the load on the AOP as much as possible. This is a very challenging task, since the type and the concentration of the toxic compounds constantly varies over time. The problem is aggravated by lack of inexpensive and fast technologies that are able to evaluate the toxicity under conditions in which the nature of the toxic compounds is unknown. Here we report on the developing of a unit that automatically measures the extent by which polluted water might put at risk a biological treatment unit. The sensing unit monitors in real time the viability of the reporting bacteria Bacillus Subtilis, using resazurin. The toxic compounds were modelled by three antibiotics (chloramphenicol, tetracycline and ciprofloxacin). The potential of embedding the sensing unit in a multi-technology system (AOP-biological) was demonstrated by connecting the sensing unit to a photocatalytic reactor and controlling the number of operating lamps in the photocatalytic reactor autonomously according to predetermined toxicity setpoint. The approach can be easily applied to almost any AOP-biotreatment tandem system, while altering any controllable parameter (residence time, light, etc.) of the AOP unit according to needs.

Assembly of a resistome in parallel with the establishment of a microbial community is not well understood. Germfree models can reveal microbiota interactions and shed light on bacterial colonization and resistance development under antibiotic pressure. In this study, we exposed germfree soil (GS), GS with diluted nontreated soil (DS), and nontreated soil (NS) to various concentrations of tetracycline (TET) in a nongermfree environment for 10 weeks, followed by 2 weeks of exposure to water. High-throughput sequencing was used to profile bacterial communities and antibiotic resistance genes (ARGs) in the soils. The initial bacterial loads were found to shape the profiles of bacterial communities and the resistomes. GS and DS treated with TET and the same soils left untreated had similar profiles, whereas NS showed different profiles. Soils with the same initial bacterial loads had their profiles shifted by TET treatment. Multidrug resistance (MDR) genes were the most abundant ARG types in all soils, with multidrug efflux pump genes being the discriminatory ARGs in GS regardless of different TET treatments and in GS, DS, and NS after TET. Furthermore, MDR genes were significantly enriched by TET treatment. In contrast, tetracycline resistance genes were either absent or low in relative abundance. The family Burkholderiaceae was predominant in all soils (except in NS treated with water) and was positively selected for by TET treatment. Most importantly, Burkholderiaceae were the primary carrier of ARGs, including MDR genes. IMPORTANCE This is the first study to examine how resistomes develop and evolve using GS. GS can be used to study the colonization and establishment of bacterial communities under antibiotic selection. Surprisingly, MDR genes were the main ARGs detected in GS, and TET treatments did not positively select for specific tetracycline resistance genes. Additionally, Burkholderiaceae were the key bacterial hosts for MDR genes in the current GS model under the conditions investigated. These results show that the family Burkholderiaceae underpins the development of resistome and serves as a source of ARGs. The ease of establishment of Burkholderiaceae and MDR genes in soils has serious implications for human health, since these bacteria are versatile and ubiquitous in the environment.

The COVID-19 pandemic has severely impacted public health and the worldwide economy. Converging evidence from the current pandemic, previous outbreaks and controlled experiments indicates that SARS-CoVs are present in wastewater for several days, leading to potential health risks via waterborne and aerosolized wastewater pathways. Conventional wastewater treatment provides only partial removal of SARS-CoVs, thus safe disposal or reuse will depend on the efficacy of final disinfection. This underscores the need for a risk assessment and management framework tailored to SARS-CoV-2 transmission via wastewater, including new tools for environmental surveillance, ensuring adequate disinfection as a component of overall COVID-19 pandemic containment. Converging evidence indicates that SARS-CoVs are present in wastewater for several days with potential health risks. This Review analyses knowledge about such risks as well as the potential spread of SARS-CoVs in waterborne, waterborne–aerosolized and waterborne–foodborne pathways during a pandemic.

Fresh herbs are not commonly associated with foodborne pathogens, due to the production of essential oils with antimicrobial activity. Recalls of contaminated basil, and basil outbreaks caused by Salmonella motivated studies aimed to comprehend the antimicrobial activity of basil essential oils, and to explore the mechanisms in which Salmonella can overcome them. Linalool, a major constituent of basil oil, increases the permeability of Salmonella Senftenberg cells by damaging their membrane. Linalool also induces bacterial aggregation. We hypothesized that the membrane perforation effect triggers cell aggregation through leakage of intracellular substances from live and dead cells. By exposing S. Senftenberg to additional physical (sonication) or chemical (eugenol, Triton-X-100) treatments, we showed that the aggregation is caused by various membrane-targeted treatments. Enzymatic degradation of leaked proteins restricted the bacterial aggregation, and disassembled existing aggregates. Moreover, supplemented proteins such as bacterial intracellular proteins or BSA also caused aggregation, further supporting the hypothesis that non-specific proteins trigger the bacterial aggregation. This study provides a novel understanding of the role of protein leakage in promoting bacterial aggregation. Since aggregation has significant roles in food safety and microbial ecology, this finding may establish future studies about microbial resistance via formation of clusters similar to biofilm development.

In this study, the phenolic profiles and bioactivities (antioxidant and antiproliferative activities) of turmeric extracts obtained by ultrasound-assisted extraction (UAE) and conventional solvent extraction (CSE) were compared. The results showed that UAE and CSE had significant effects (p < 0.05) on phenolic composition, antioxidant activities, and antiproliferative effects. Compared with CSE, UAE can significantly (p < 0.05) increase extraction efficiency of phenolic compounds. Turmeric extracts obtained by UAE exhibited stronger antiproliferative effects against a panel of cancer cell lines (MCF7, MDA-MB-231, HCT116, HT29, HepG2, HeLa) than that obtained by CSE. In addition, the turmeric extracts can reduce the generation of reactive oxygen species (ROS), inhibit cell migration, induce cell morphological changes and nuclear condensation, and arrest cell cycle at S and G2/M phases. The present findings suggested that ultrasonication can be applied successfully for the extraction of bioactive constituents from turmeric with enhanced biological activities, and the turmeric extracts have antiproliferative effects which may be mediated through ROS modulation and cell cycle arrest. Overall, turmeric extracts can be considered as a potential source of bioactive compounds for the treatment of cancer-related diseases.

Seeds are inhabited by diverse bacterial and fungal taxa whose colonization patterns are little understood. We hypothesized, however, that specific niches within seeds host microbes.

Injectable drug delivery systems that autonomously detect, propel towards, and ultimately treat the cancerous tissue, are the future of targeted medicine. Here, we developed a drug delivery system that swims autonomously towards cancer cells, where it releases a therapeutic cargo. This platform is based on viable bacteria, loaded with nanoparticles that contain the chemotherapeutic-antibiotic drug doxorubicin. The bacteria ferry across media and invade the cancer cells, increasing their velocity in the presence of nutrients that are present within the tumor microenvironment. Inside the cancer cells, doxorubicin is released from the nanoparticles, destroying the bacterial swimmer (antibiotic activity) and executing the therapeutic activity against the cancer cells (chemotherapeutic activity). This mode of delivery, where both the carrier and the cancer cell are destroyed, supports implementing nanoswimmers in drug delivery (Fig. 1).

ABSTRACT A clinical isolate of Salmonella enterica serovar Senftenberg, isolated from an outbreak linked to the herb Ocimum basilicum L. (basil), has been shown to be resistant to basil oil and to the terpene alcohol linalool. To better understand how human pathogens might develop resistance to linalool and to investigate the association of this resistance with resistance to different antimicrobial agents, selective pressure was applied to the wild-type strain by sequential exposure to increasing concentrations of linalool. The results demonstrated that S . Senftenberg adapted to linalool with a MIC increment of at least 8-fold, which also resulted in better resistance to basil oil and better survival on harvested basil leaves. Adaptation to linalool was shown to confer cross protection against the antibiotics trimethoprim, sulfamethoxazole, piperacillin, chloramphenicol, and tetracycline, increasing their MICs by 2- to 32-fold. The improved resistance was shown to correlate with multiple phenotypes that included changes in membrane fatty acid composition, induced efflux, reduced influx, controlled motility, and the ability to form larger aggregates in the presence of linalool. The adaptation to linalool obtained in vitro did not affect survival on the basil phyllosphere in planta and even diminished survival in soil, suggesting that development of extreme resistance to linalool may be accompanied by a loss of fitness. Altogether, this report notes the concern regarding the ability of human pathogens to develop resistance to commercial essential oils, a resistance that is also associated with cross-resistance to antibiotics and may endanger public health. IMPORTANCE Greater consumer awareness and concern regarding synthetic chemical additives have led producers to control microbial spoilage and hazards by the use of natural preservatives, such as plant essential oils with antimicrobial activity. This report establishes, however, that these compounds may provoke the emergence of resistant human pathogens. Herein, we demonstrate the acquisition of resistance to basil oil by Salmonella Senftenberg. Exposure to linalool, a component of basil oil, resulted in adaptation to the basil oil mixture, as well as cross protection against several antibiotics and better survival on harvested basil leaves. Collectively, this work highlights the hazard to public health while using plant essential oils without sufficient knowledge about their influence on pathogens at subinhibitory concentrations.

Researchers are gaining an increasing understanding of host–gut microbiota interactions, but studies of the role of gut microbiota in linear growth are scarce. The aim of this study was to investigate the effect of food restriction and refeeding with different diets on gut microbiota composition in fast-growing rats. Young male Sprague–Dawley rats were fed regular rat chow ad libitum (control group) or subjected to 40% food restriction for 36 days followed by continued restriction or ad libitum refeeding for 24 days. Three different diets were used for refeeding: regular vegetarian protein chow or chow in which the sole source of protein was casein or whey. In the control group, the composition of the microbiota remained stable. Food restriction for 60 days led to a significant change in the gut microbiota at the phylum level, with a reduction in the abundance of Firmicutes and an increase in Bacteroidetes and Proteobacteria. Rats refed with the vegetarian protein diet had a different microbiota composition than rats refed the casein- or whey-based diet. Similarities in the bacterial population were found between rats refed vegetarian protein or a whey-based diet and control rats, and between rats refed a casein-based diet and rats on continued restriction. There was a significant strong correlation between the gut microbiota and growth parameters: humerus length, epiphyseal growth plate height, and levels of insulin-like growth factor 1 and leptin. In conclusion, the type of protein in the diet significantly affects the gut microbiota and, thereby, may affect animal's health.

ABSTRACT Here we report the genome sequences of both Salmonella Senftenberg 070885, a clinical isolate from the 2007 outbreak linked to basil, and its mutant linalool-adapted S. Senftenberg (LASS). These draft genomes of S. Senftenberg may enable the identification of bacterial genes responsible for resistance to basil oil.

BACKGROUNDWater purification is challenged by the co-presence of contaminants, some of which are too toxic for bacteria or too opaque for photocatalytic processes. This challenge may be overcome by utilizing two types of reactors (for example biological and photocatalytic) operating in sequence. Realization of this approach should be based on a steady state model for calculating the optimal design under nominal conditions, a non-steady state responding to fluctuating conditions and fast measurement of toxicity and turbidity.RESULTSA steady-state model, examining the effect of coexisting toxicity and turbidity on the optimal sequence, on the relative retention times in the two reactors and on the effect of recycling, under an estimated cost function constraint is presented. It was found that the optimal sequence depends on the relative importance of toxicity and turbidity, that a single branch operation is likely to be more cost effective than dual branch (Biophotocatalytic in parallel with photocatalyticBio) system.CONCLUSIONIt is recommended to add the possibility for altering flow direction to account for operation under non-nominal conditions. To decrease instability during flow-direction switching, a recycling option should be added. Recycling may also be beneficial in particular when the activated biological medium has sluggish kinetics. (c) 2017 Society of Chemical Industry

Salmonella enterica (S. enterica) can form multicellular structures, commonly called biofilms, on various occasions. Biofilms can be formed on diverse surfaces/interfaces such as at the epithelial cell layer of a vertebrate host, on plant surfaces, or on abiotic surfaces, at the air–liquid interface and on gallstones. In this way, S. enterica is thought to achieve environmental persistence, transmission, and colonization of host organisms. Characterization of biofilm formation at the molecular level revealed different types of biofilms that have common and distinct regulatory and structural components. The so-called “rdar morphotype,” a multicellular behavior of S. enterica on agar plates is characterized by the expression of the master regulator CsgD, which controls expression of the extracellular matrix components curli fimbriae, the large surface-associated protein BapA, the exopolysaccharide cellulose and a capsular polysaccharide. Colonization of abiotic surfaces, plant surfaces and epithelial cell layers partly require the same factors as rdar morphotype formation, while the biofilm formed by Salmonella on gall stones seems to be substantially distinct from rdar morphotype formation. Introduction Salmonella enterica, in particular serovar Typhimurium (S. Typhimurium) and Enteritidis (S. Enteritidis) have mainly been studied as pathogens in the process of causing disease (Hensel, 2004; Hurley and McCormick, 2003). However, often S. enterica is a regular colonizer of warmand coldblooded animals without causing disease. Although animals and humans act as host organisms for salmonellae, the life cycle of S. enterica is complex and includes stages outside of the host (Winfield and Groisman, 2003). For example, S. enterica has to be effectively transmitted between hosts either by close contact, or through animate or inanimate vehicles such as water, food and produce. Effective survival outside a host is consequently an essential component of the life cycle of S. enterica. Since life outside and inside a host is fundamentally different, S. enterica has to tightly regulate gene expression in order to survive in both environments (Mouslim et al., 2002). A multicellular behavior, commonly called biofilm-formation, is expressed by almost all bacteria and can play roles in virulence and host colonization as well as for the survival outside a host. In this review, current knowledge about biofilm formation in S. enterica is summarized. S. enterica caister.com/biofilmsbooks Römling et al. 128 | forms biofilms on different surfaces in the host such as at the epithelial cell layer or on gall stones; is able to colonize plant surfaces for transmission of the pathogen and colonizes abiotic surfaces such as stainless steel and glass. Elucidation of the molecular basis of biofilm formation has revealed that similar and distinct components are required for biofilm formation on different surfaces. Definition of biofilm