Biofilm Formation Rate Research Articles

Biofouling of seawater reverse osmosis membranes caused by dispersal of planktonic particulate bacterial aggregates (protobiofilms) from rotary energy recovery devices

A seawater reverse osmosis (SWRO) plant in the Arabian Gulf region showed serious membrane biofouling that appeared to be due to the presence of planktonic particulate bacterial aggregates that can be termed as “protobiofilms”, which possessed the same characteristics of surface-attached biofilms. This SWRO plant utilized dissolved air flotation and ultrafiltration for pretreatment, high permeable SWRO membranes for desalination and incorporated rotary energy recovery devices (RERD). During the first year of operation, a slow steady increase in TMP and channel ∆P was observed that appeared due to membrane biofouling from either colloidal small bacterial aggregates or individual bacterial cells. After the first year of operation, the TMP and channel ∆P increased at an accelerated rate that appeared due presence of planktonic particulate bacterial aggregates. An internal membrane hybridization (IMH) program was initiated after the second year of operation by replacing the two highly fouled high permeable membranes in the feed-end of the pressure vessel with new low permeable membranes to lower the flux and concentration polarization (CP) of the feed-end membranes and to lower the membrane fouling potential. Biofouling of these new low permeable membranes in the IMH program resulted in an immediate and an accelerated increase in both TMP and channel ∆P, which was attributed to the presence of significant concentration of planktonic particulate bacterial aggregates that appeared due to dispersal of a biofilm from the RERD. An important factor that contributed to the dispersal of bacterial aggregates into the RO feed water was the flow velocity through the RERD. Decreasing the flow velocity into and cleaning of the RERD resulted in a significant decrease in the rate of RERD biofilm dispersal and biofilm formation on the SWRO modules.

Virulence, biofilm formation ability and antimicrobial resistance of Staphylococcus aureus isolated from cell phones of university students

Introduction: Contamination of cell phones can contribute to the dissemination of pathogens in the community and/or hospital environment. Objective: To characterize Staphylococcus aureus strains isolated from cell phones of university students. Methods: Samples were collected from 100 cell phones. Detection of genes associated with virulence factors such as biofilm formation (icaA and icaD), enterotoxins production (SEA, SEB, SEC, and SED), and resistance to methicillin (mecA and mecC) was performed in S. aureus isolates by PCR. Typing mecA gene performed by multiplex PCR. Susceptibility to antimicrobials and biofilm formation rate also evaluated by using disk diffusion test and crystal violet staining. Results: S. aureus was present in 40% of the total samples and about 70% of them belonged to Nursing students. Of the isolates, 85% presented resistance to penicillin and 50% were classified as moderate biofilm producers. In addition, 92.5% of isolates contained the gene icaA and 60% of the gene icaD. Approximately 25% of the isolates presented the mecA gene. Typing of the mecA gene showed the presence of staphylococcal chromosome cassette SCCmec I and c III respectively in 20% and 10% of the isolates. 70% of the samples could not be typed by the technique. Regarding the enterotoxins, the most prevalent gene was SEA (30%) followed by the SEC gene (2.5%). The presence of SED and SEB genes not observed in any of the isolates. Conclusion: The cleaning and periodic disinfection of cell phones can contribute to the reduction of the risk of nosocomial infection.

Prevalence of biofilms in Candida spp. bloodstream infections: A meta-analysis.

Candida-related infections are nowadays a serious Public Health Problem emerging multidrug-resistant strains. Candida biofilm also leads bloodstream infections to invasive systemic infections. The present meta-analysis aimed to analyze Candida biofilm rate, type, and antifungal resistance among hospitalized patients between 1995 and 2020. Web of Science, Scopus, PubMed, and Google Scholar databases were searched for English papers using the following medical subject heading terms (MESH): "invasive candidiasis"; "bloodstream infections"; "biofilm formation"; "biofilm-related infections"; "mortality"; and "prevalence". The major inclusion criteria included reporting the rate of biofilm formation and the prevalence of biofilm-related to Candida species, including observational studies (more exactly, cohort, retrospective, and case-control studies). Furthermore, data regarding the mortality rate, the geographical location of the study set, and the use of anti-fungal agents in clinical isolates were also extracted from the studies. Independent extraction of articles by 2 authors using predefined data fields, including study quality indicators. A total of 31 studies from publicly available databases met our inclusion criteria. The biofilm formation in the data set varied greatly from 16 to 100% in blood samples. Most of the studies belonged to Europe (17/31) and Asia (9/31). Forest plot showed a pooled rate of biofilm formation of 80.0% (CI: 67-90), with high heterogeneity (Q = 2567.45, I2 = 98.83, τ2 = 0.150) in random effects model (p < 0.001). The funnel plot and Egger's linear regression test failed to find publication bias (p = 0.896). The mortality rate in Candida-related bloodstream infections was 37.9% of which 70.0% were from biofilm-associated infections. Furthermore, Candida isolates were also characterized in low, intermediate, or high biofilm formers through their level of biofilm mass (crystal violet staining or XTT assays) after a 24h growth. When comparing between countries, statistical differences were obtained (p = 0.0074), showing the lower and higher biofilm prevalence values in Italy and Spain, respectively. The prevalence of low, intermediate, and high biofilms were 36.2, 18.9, and 35.0% (p < 0.0001), respectively. C. tropicalis was the prevalent species in high biofilm formation (67.5%) showing statistically significant differences when compared to other Candida species, except for C. krusei and C. glabrata. Finally, the rates of antifungal resistance to fluconazole, voriconazole, and caspofungin related to biofilm were 70.5, 67.9 and 72.8% (p < 0.001), respectively. Early detection of biofilms and a better characterization of Candida spp. bloodstream infections should be considered, which eventually will help preserve public health resources and ultimately diminish mortality among patients.

Biofilm-forming microorganisms causing hospital-acquired infections from intravenous catheter: A systematic review

The high prevalence of nosocomial infections is related to the use of medical insertion devices such as central venous catheters (CVCs). Most of the microorganisms causing nosocomial infections are biofilm producers, this characteristic allows them to adhere to abiotic surfaces and cause initial catheter infections that can lead to bloodstream infections. Our main goal in this systematic review was to evaluate the prevalence of biofilm among CVC-related infections, particularly among Intensive Care Unit (ICU) patients, in the studies applying different in vitro and in vivo methodologies. All studies reporting clinical isolates from patients with catheter-related nosocomial infections and biofilm evaluation published up to 24 June 2022 in the PubMed and Scopus databases were included. Twenty-five studies met the eligibility criteria and were included in this systematic review for analysis. Different methodologies were applied in the assessment of biofilm-forming microorganisms including in vitro assays, catheter-infected in vitro, and in vivo mouse models. The present study showed that between 59 and 100% of clinical isolates were able to form biofilms, and the prevalence rate of biofilm formation varied significantly between studies from different countries and regions. Among the clinical isolates collected in our study set, a wide variety of microorganisms including Gram-positive strains, Gram-negative strains, and Candida albicans were found. Many authors studied resistance mechanisms and genes related to biofilm development and surface adherence properties. In some cases, the studies also evaluated biofilm inhibition assays using various kinds of catheter coatings.

Optimization of Quantitative Analysis of Biofilm Cell from Pipe Materials

The quantitative analysis of biofilm can be used not only to assess the microbiological stability of tap water but also on its basis can assess: the degree of colonization of materials by bacterial cells, the rate of biofilm formation on the surfaces of pipes and determine their composition and number. The article presents the results of research on the development of an effective method of biofilm detachment from the surface of the galvanized steel. The number of biofilm cells was determined by methods: (1) luminometric ATP determination, (2) flow cytometry and (3) heterotrophic plate counts (HPC). The presence of the biofilm was confirmed by SEM and fractal analysis. The analysis of the obtained results showed that the most effective method of detaching the biofilm cells from the galvanized steel surface was the mechanical separation with a sterile cotton swab. The variant with the use of a sterile swab enables rapid collection of the biofilm from the surface of the ducts forming internal installations or water supply networks. Due to the simplicity and speed of obtaining results, the luminometric ATP measurement has been established as the best method for the quantification of biofilm cells. The results of this study were intended to provide reliable and useful data on the quantification of biofilm cells.

No Correlation between Biofilm Formation, Virulence Factors, and Antibiotic Resistance in Pseudomonas aeruginosa: Results from a Laboratory-Based In Vitro Study.

Pseudomonas aeruginosa (P. aeruginosa) possesses a plethora of virulence determinants, including the production of biofilm, pigments, exotoxins, proteases, flagella, and secretion systems. The aim of our present study was to establish the relationship between biofilm-forming capacity, the expression of some important virulence factors, and the multidrug-resistant (MDR) phenotype in P. aeruginosa. A total of three hundred and two (n = 302) isolates were included in this study. Antimicrobial susceptibility testing and phenotypic detection of resistance determinants were carried out; based on these results, isolates were grouped into distinct resistotypes and multiple antibiotic resistance (MAR) indices were calculated. The capacity of isolates to produce biofilm was assessed using a crystal violet microtiter-plate based method. Motility (swimming, swarming, and twitching) and pigment-production (pyoverdine and pyocyanin) were also measured. Pearson correlation coefficients (r) were calculated to determine for antimicrobial resistance, biofilm-formation, and expression of other virulence factors. Resistance rates were the highest for ceftazidime (56.95%; n = 172), levofloxacin (54.97%; n = 166), and ciprofloxacin (54.64%; n = 159), while lowest for colistin (1.66%; n = 5); 44.04% (n = 133) of isolates were classified as MDR. 19.87% (n = 60), 20.86% (n = 63) and 59.27% (n = 179) were classified as weak, moderate, and strong biofilm producers, respectively. With the exception of pyocyanin production (0.371 ± 0.193 vs. non-MDR: 0.319 ± 0.191; p = 0.018), MDR and non-MDR isolates did not show significant differences in expression of virulence factors. Additionally, no relevant correlations were seen between the rate of biofilm formation, pigment production, or motility. Data on interplay between the presence and mechanisms of drug resistance with those of biofilm formation and virulence is crucial to address chronic bacterial infections and to provide strategies for their management.

Antimicrobial and Antibiofilm Effect of ε-Polylysine against Salmonella Enteritidis, Listeria monocytogenes, and Escherichia coli in Tryptic Soy Broth and Chicken Juice.

ε-Polylysine (ε-PL) is a safe food additive that is used in the food industry globally. This study evaluated the antimicrobial and antibiofilm activity of antibacterial peptides (ε-PL) against food poisoning pathogens detected in chicken (Salmonella Enteritidis, Listeria monocytogenes, and Escherichia coli). The results showed that minimum inhibitory concentrations (MICs) ranged between 0.031–1.0 mg/mL, although most bacterial groups (75%) showed MICs of 1.0 mg/mL. The reduction in the cell viability of pathogens due to ε-PL depended on the time and concentration, and 1/2 × MIC of ε-PL killed 99.99% of pathogens after 10 h of incubation. To confirm biofilm inhibition and degradation effects, crystal violet assay and confocal laser scanning microscopy (CLSM) were used. The biofilm formation rates of four bacterial groups (Salmonella, Listeria, E. coli, and multi-species bacteria) were 10.36%, 9.10%, 17.44%, and 21.37% at 1/2 × MIC of ε-PL, respectively. Additionally, when observed under a CLSM, ε-PL was found to induce biofilm destruction and bacterial cytotoxicity. These results demonstrated that ε-PL has the potential to be used as an antibiotic and antibiofilm material for chicken meat processing.

Use of a packed-bed biofilm reactor to achieve rapid formation of anammox biofilms for high-rate nitrogen removal

Anammox is an efficient and carbon-saving process for biological nitrogen removal; however, the long start-up period and poor stability of anammox bioreactors hinder their application in wastewater treatment. An innovative technical strategy was developed in this study that used a packed-bed biofilm reactor (PBBR) to grow healthy anammox biofilms for the fast start-up of bioreactors. With a greatly reduced fluid turbulence in the PBBR, the attachment and growth of anammox biofilms were found to be accelerated and the specific anammox biofilm formation rate was 60% higher than that in the conventional moving-bed biofilm reactor (0.032 vs. 0.020/d). In the PBBR operation, maintaining a low free ammonia (<2.7 mg/L) and free nitrous acid (<5.8 μg/L) concentrations in the early stage and stepwise increasing the nitrogen load also assisted the biofilm formation. With the rapid anammox biofilm formation and growth, the nitrogen removal capacity of the PBBR increased from 77.6 to 876.8 mg N/(L·d) in 2 months. The anoxic condition and prolonged sludge retention time in the PBBR also benefited the growth of fermentative bacteria and denitrifiers, which induced the partial denitrification–anammox process and decreased the nitrate accumulation by 50%.

Effect of ZnO nanoparticles on methicillin, vancomycin, linezolid resistance and biofilm formation in Staphylococcus aureus isolates

BackgroundMultidrug resistant (MDR) and biofilm producing Staphylococcus aureus strains are usually associated with serious infections. This study aimed to evaluate the antibacterial and antibiofilm-formation effects of zinc oxide nanoparticles (ZnO-NPs) against staphylococcus aureus (S. aureus) isolates.MethodsA total of 116 S. aureus isolates were recovered from 250 burn wound samples. The antimicrobial/antibiofilm effects of ZnO-NPs against methicillin, vancomycin and linezolid resistant S. aureus (MRSA, VRSA and LRSA) isolates were examined using phenotypic and genotypic methods. The minimum inhibitory concentration (MIC) of ZnO-NPs was determined by microdilution method. The effects of sub-MIC concentrations of ZnO-NPs on biofilm formation and drug resistance in S. aureus were determined by the microtiter plate method. The change in the expression levels of the biofilm encoding genes and resistance genes in S. aureus isolates after treatment with ZnO-NPs was assessed by real time reverse transcriptase PCR (rt-PCR).ResultsMICs of ZnO-NPs in S. aureus isolates were (128–2048 µg/ml). The sub-MIC of ZnO-NPs significantly reduced biofilm formation rate (the highest inhibition rate was 76.47% at 1024 µg/ml) and the expression levels of biofilm genes (ica A, ica D and fnb A) with P < 0.001. Moreover, Sub-MIC of ZnO-NPs significantly reduced the rates of MRSA from 81.9 (95 isolates) to 13.30% (15 isolates), VRSA from 33.60 (39 isolates) to 0% and LARSA from 29.30 (34) to 0% as well as the expression levels of resistance genes (mec A, van A and cfr) with P value < 0.001.ConclusionZnO-NPs can be used as antibiofilm and potent antimicrobial against MRSA, VRSA and LRSA isolates.

ALS3 Expression as an Indicator for Candida albicans Biofilm Formation and Drug Resistance.

Resistance caused by the formation of the Candida albicans (C. albicans) biofilm is one of the main reasons for antifungal therapy failure. Thus, it is important to find indicators that predict C. albicans biofilm formation to provide evidence for the early prevention and treatment of the C. albicans biofilms. In this study, C. albicans samples were selected from C. albicans septicemia that were sensitive to common antifungal agents. It was found that the agglutinin-like sequence 3 (ALS3) gene was differentially expressed in free, antifungal, drug-sensitive C. albicans. The average ALS3 gene expression was higher in the C. albicans strains with biofilm formation than that in the C. albicans strains without biofilm formation. Then, it was further confirmed that the rate of biofilm formation was higher in the high ALS3 gene expression group than that in the low ALS3 gene expression group. It was found that C. albicans with biofilm formation was more resistant to fluconazole, voriconazole, and itraconazole. However, it maintained its sensitivity to caspofungin and micafungin in vitro and in mice. Further experiments regarding the prevention of C. albicans biofilm formation were performed in mice, in which only caspofungin and micafungin prevented C. albicans biofilm formation. These results suggest that the expression level of ALS3 in C. albicans may be used as an indicator to determine whether C. albicans will form biofilms. The results also show that the biofilm formation of C. albicans remained sensitive to caspofungin and micafungin, which may help to guide the selection of clinical antifungal agents for prevention and therapy.

Mathematical Models for the Biofilm Formation of Geobacillus and Anoxybacillus on Stainless Steel Surface in Whole Milk.

Biofilm formation of Geobacillus thermodenitrificans, Geobacillus thermoglucosidans and Anoxybacillus flavithermus in milk on stainless steel were monitored at 55°C, 60°C, and 65°C for various incubation times. Although species of Geobacillus showed a rapid response and produced biofilm within 4 h on stainless steel, a delay (lag time) was observed for Anoxybacillus. A hyperbolic equation and a hyperbolic equation with lag could be used to describe the biofilm formation of Geobacillus and Anoxybacillus, respectively. The highest biofilm formation amount was obtained at 60°C for both Geobacillus and Anoxybacillus. However, the biofilm formation rates indicated that the lowest rates of formation were obtained at 60°C for Geobacillus. Moreover, biofilm formation rates of G. thermodenitrificans (1.2–1.6 Log10CFU/mL·h) were higher than G. thermoglucosidans (0.4–0.7 Log10CFU/mL·h). Although A. flavithermus had the highest formation rate values (2.7–3.6 Log10CFU/mL·h), this was attained after the lag period (4 or 5 h). This study revealed that modeling could be used to describe the biofilm formation of thermophilic bacilli in milk.

The Ability of Staphylococcus spp. Isolated from Minced Meat to Adhere and form Biofilm on the Aluminum and Stainless-Steel Surfaces

The research included isolation and diagnosis of 19 bacterial isolate from 10 samples (minced meat and meat mincer), as 15 isolates belonging to the Micrococcaceae were diagnosed including 8 Staphylococcus spp. Isolates depending on the phenotypic properties and biochemical test, and in order to investigate the bacterial ability of the Micrococcaceae family to the formation of biofilms, two methods are used, the tube method and the Congo red agar method, as the results showed that all of the 15 isolates possess the ability to form biofilms as 100% depending on The tube method compared to the results of the Congo red agar test, which gave 13 positive result of 15 isolates in ratio 86.6% of the Micrococceae family. The highest rate of biofilm formation attributed to the Staphylococcus spp. which it gives 8 positive result for both tests as 100%. When comparing the adhesiveness of Staphylococcus spp. on the surface of the aluminum and stainless steel coupons as the materials used in the manufacture of meat mincers, our results showed that the adhesion and formation of biofilms were high on the surface of the aluminum coupons compared to the stainless steel coupons in the turbidity test using sonication and when investigating the total number of bacteria attached to the aluminum and steel coupons after exposing them to sonication, it was found that the number of units forming colonies CFU / cm2 for the aluminum coupons is 97 × 106, while it was found that CFU / cm2 of stainless steel coupons is 172 x 105, which enhances the turbidity comparison results.

Reliable Sea Water Ro Operation with High Water Recovery and No-Chlorine/No-Sbs Dosing in Arabian Gulf, Saudi Arabia.

For providing advanced desalination the combination of the improvement of water recovery ratio in the reverse osmosis (RO) process and the No-Chlorine/No-Sodium Bisulfite (SBS) Dosing process was studied. In order to prevent membrane fouling even in high recovery water operations, an advanced two-stage design was implemented to (1) control the permeate flux through the RO membrane module, (2) optimize the system to reduce contaminant build-up and (3) eliminate the use of chlorine and SBS, which can accelerate membrane fouling. The system was evaluated by monitoring the biofouling and the microorganisms proliferation on the membrane surface based on membrane biofilm formation rate (mBFR). The pilot plant was operated in the condition of a water recovery rate of 55%. As a result, the system was operated for longer than four months without membrane cleaning (clean in place; CIP) and the possibility of operation for seven months without CIP was confirmed by the extrapolation of the pressure values. In addition, the mBFR is a reliable tool for water quality assessment, based on a comparison between the fouling tendency estimated from the mBFR and the actual membrane surface condition from autopsy study and the effectiveness No-Chlorine/No-SBS Dosing process was verified from mBFR of pretreated seawater.

ASSOCIATION BETWEEN THE STREPTOCOCCUS MUTANS BIOFILM FORMATION AND DENTAL CARIES EXPERIENCE AND ANTIBIOTICS RESISTANCE IN ADULT FEMALES

Objectives: The aim of this study was to consider the potential association between the formation of salivary streptococcus biofilms and the incidence of caries, as well as with the occurrence of antibiotic resistance among adult mothers in Sana'a, Yemen. &#x0D; Study design: A total of 261; 25-35 year old females were chosen. Clinical examination of females were performed to estimate dental caries experience with the Silness-Loe index, as well as stimulated saliva were collected to assess biofilm production by the phenotypic method i.e. Tissue culture palate methods (TCPM). Finally, antibiogram susceptibility pattern of isolated S. mutans was done by Kirby-Bauer disc diffusion method for 6 β-Lactam antibiotics (ampicillin, penicillin, amoxicillin, cefotaxime, methicillin and cefazolin) and 4 non β-Lactam antibiotics (clindamycin, erythromycin, lincomycin and vancomycin).&#x0D; Results: When isolated S. mutans were exposed to biofilm detection by TCP method, 31 (12.2%) showed high biofilm formation capacity, 46 (18%) showed moderate biofilm formation capacity, while 184 (72.2%) showed non / weak formation capacity of biofilm. The overall rate of biofilm formation was 30.2%. There was an escalation in the rate of formation of S. mutans biofilms with an increased degree of caries index. The S. mutans biofilms positve showed a higher rate of resistance than non/weak biofilm formation e.g ampicillin (28.6% versus 12.9%, p = 0.002), amoxicillin (77.9% versus 18%, p &lt;0.0001), and penicillin (79.2 % versus 23%, &lt;0.0001) etc. &#x0D; Conclusion: The present study proved that S. mutans is still the major bacteria isolate from the oral cavity, but few persons might not have significant number of S. mutans in oral cavity. The S. mutans biofilm - producers were more able to cause dental caries compared to the S. mutans biofilm-non-producers. Drug resistant factor in the S. mutans isolates was found to be associated with S. mutans biofilm formation.&#x0D; &#x0D; Peer Review History: &#x0D; Received 12 November 2020; Revised 20 Decembe; Accepted 5 January, Available online 15 January 2021&#x0D; UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency.&#x0D; Received file: Comments of reviewer(s): &#x0D; Average Peer review marks at initial stage: 6.5/10&#x0D; Average Peer review marks at publication stage: 8.0/10&#x0D; Reviewer(s) detail:&#x0D; Dr. Alfonso Alexander Aguileral, University of Veracruz, Mexico, aalexander_2000@yahoo.com&#x0D; Dr. George Zhu, Tehran University of Medical Sciences, Tehran, Iran, sansan4240732@163.com&#x0D; Similar Articles:&#x0D; CAUSES FOR EXTRACTION OF PERMANENT TEETH IN GENERAL DENTAL PRACTICES IN YEMEN &#x0D; PREVALENCE OF STAPHYLOCOCCUS AUREUS IN DENTAL INFECTIONS AND THE OCCURRENCE OF MRSA IN ISOLATES

Lubrication dynamics of swollen silicones to limit long term fouling and microbial biofilms.

Bacterial contamination and biofilm formation on medical devices remain a costly and serious healthcare problem. Silicone (polydimethylsiloxane, PDMS) elastomers are common biomaterials but are susceptible to bacterial surface contamination and biofilm growth. 'Self-lubricated' PDMS elastomers (iPDMS) have the potential to greatly reduce rates of cell attachment, biofilm formation and infection. Cross-linked PDMS elastomers immersed in PDMS oil swell to an equilibrium concentration to form a swollen network, and then form a surface liquid layer through syneresis. Herein we have measured the swelling and syneresis kinetics as a function of time, viscosity (1.5 to 10 cSt), and cross-linking density to optimize the surface lubricant layer formation, and resistance to biofouling. The lubricant layer thickness was measured in situ (optical profilometry and AFM) for flat and micro-textured surfaces, as a function of time and swelling ratio, to be in a range from 0.1 to 1 μm, and continuously increases with time. We show this continuous generation is likely due to a gradual, dynamic re-structuring of the elastomer network. Long term antifouling properties of (10 cSt) iPDMS were tested for Pseudomonas aeruginosa growth in a flow culture bioreactor, and after 30 d showed a 103 to 104 reduction of bacterial cell density for iPDMS compared to conventional PDMS elastomers. This long term performance and non-specific activity makes them highly suitable for biomedical devices, such as urinary catheters.

Прогнозирование развития реактивного артрита у детей с дисплазией соединительной ткани

Objective. To develop a model for automated prediction of the development of recurring reactive arthritis in children with symptoms of connective tissue dysplasia (CTD). Patients and methods. The work included two stages. At the first stage, in order to identify the predisposing factors to the development of reactive arthritis (ReA), two age- and sex-representative groups of children aged 3-17 years were formed: group 1 consisted of children with ReA (50 patients), group 2 – comparison group (25 conditionally healthy children from the general population). All children underwent a standard clinical examination with determination of CTD symptoms, and microbiological examination, including evaluation of the state of microbiocenosis of the distal colon by degrees; the ability of isolated microorganisms to biofilm formation (BF); levels of lactoferrin (LF) and lysozyme (LZC) in coprofiltrates of children. At the second stage, to create an automated prediction model, two additional groups of children were formed: 30 conditionally healthy children with CTD symptoms without arthritis and 30 conditionally healthy children without CTD symptoms. Stepwise discriminant analysis (DA) and the method of resultants mapping were used. Results. The factors determining the risk of ReA development in children with connective tissue dysplasia were identified. Highly informative markers associated with the development and course of ReA were established: the presence of external phenotypic symptoms and dysplasia of internal organs; dysbiotic disorders of the distal large intestine; high rates of microbial contamination and BF of intestinal microsymbionts; increased levels of LF and LZC in coprofiltrates of children. Conclusion. The diagnostic algorithm for automated prediction of the development of arthritis recurrence was developed, which allows primary care physicians to solve the problem of secondary prevention of ReA. Key words: reactive arthritis, children, connective tissue dysplasia, intestinal microbiota, prediction method

Efficacy of endotracheal tube suctioning in intubated intensive care unit patients determined by in vivo catheter-based optical coherence tomography-a pilot study.

Mechanical ventilation using an endotracheal tube (ETT) is one of the critical interventions given to patients in the intensive care unit (ICU). ETTs are associated with the formation of biofilms, placing patients at increased risk for developing ventilator-associated pneumonia (VAP). ETT suctioning is used to remove secretions, reduce bacterial colonization, and reduce the rate of biofilm formation. However, current standard-of-care suctioning procedures do not adequately eliminate all secretions from the ETT. This observational study was conducted in a cohort of 4 subjects admitted to the ICU and intubated with an ETT, irrespective of ethnicity, gender, or race. A total of 23 suctioning procedures were evaluated with in vivo three-dimensional (3D) optical coherence tomography (OCT) imaging, before and after suctioning. A secretion density metric was derived from the OCT data to quantify the amount of secretions present within the ETT, and an attenuation coefficient metric was derived to detect and quantify the presence of biofilms. Analyzed OCT images were correlated with clinical and microscopy data. Data obtained suggests that the current standard-of-care suctioning procedure is inefficient at clearing secretions or preventing the formation of biofilms. The presence of biofilms was corroborated with both post-intubation microscopy of the ETTs, as well as with clinical data. We conclude that the standard-of-care suctioning method does not eliminate secretions nor reduce the formation of biofilm in ETTs. Our in situ imaging method was sensitive to the presence of secretions, biofilms, and quantitative, and can be used for investigating different suctioning protocols in the future.

Inhibitory Effect of Vanillin on Biofilm Formation by Multi-Species Wastewater Culture

This paper mainly investigates the inhibitory effect and mechanism of vanillin on mixed-culture biofilm formation, and discusses the feasibility of controlling membrane fouling with vanillin. The biofilms were cultured under static conditions and a microfluidic chamber, respectively. The results show that vanillin can effectively inhibit the microbial adhesion and biofilm formation; the inhibition rate increases with the vanillin concentration. After 12h treatment with 300mg/L vanillin, the inhibition rate of biofilm formation reached 85.34%. Besides, vanillin can mitigate bacterial adhesion by reducing the microbial secretion of exoprotein and exopolysaccharide, exhibit an inhibitory effect on the expression of N-acyl-l-homoserine lactones (AHLs), but had no effect on environmental deoxyribonucleic acid (eDNA). After being treated with 300mg/L vanillin, exoprotein, exopolysaccharide and AHLs decreased by 28.48%, 17.23% and 46.64%, respectively. Furthermore, there is a positive correlation between the AHLs and the content of extracellular polymeric substances (EPSs); the AHLs-mediated quorum sensing (QS) might be related to microbial adhesion through the regulation of EPS. Finally, vanillin has a great potential in membrane fouling control. The research findings provide a good reference for biofilm control in water purification and wastewater treatment systems.

Silver nanoparticles incorporated polyaniline on TiO2 nanotube arrays: A nanocomposite platform to enhance the biocompatibility and antibiofilm

The premature failure of titanium orthopaedic implant occurs mainly due to infections and non-reunion of fractures. Encouragingly, the controlling of infections and fracture reunion was effective with metal nanoparticles and conducting polymers. In this present work, the nanocomposite of silver nanoparticles incorporated polyaniline (PANI) on TiO2 nanotube arrays (TNTA) was fabricated by electropolymerization. The nanocomposite had effectively declined the rate of biofilm formation and enhanced cellular responses. Moreover, the corrosion rate was regressed that undermines the release of titanium wear-out particles. Collectively, the work illustrates the significant usage of multifunctional nanocomposite for achieving the synergetic effect on antibiofilm, antibacterial and better osseointegration.

In vitro Interactions between Streptococcus intermedius and Streptococcus salivarius K12 on a Titanium Cylindrical Surface.

Peri-implantitis is a steadily rising disease and is caused by oral bacterial pathogens able to form biofilm on implant surfaces and peri-implant tissues, making antibiotics treatment less effective. The use of commercial probiotics against oral pathogens could serve as an alternative to prevent biofilm formation. Streptococcus intermedius is one of the early colonizers of biofilm formation in dental implants. The aim of this study was to model the interaction between S. intermedius and Streptococcus salivarius strain K12, a probiotic bacterium producing bacteriocins. S. intermedius was co-cultured with S. salivarius K12 in an in vitro model simulating the biofilm formation in a dental implant composed by a titanium cylinder system. Biofilm formation rate was assessed by Real-Time PCR quantification of bacterial count and expression levels of luxS gene, used in response to cell density in the biofilm. Biofilm formation, bacteriocin production, luxS expression patterns were found to be already expressed within the first 12 h. More importantly, S. salivarius K12 was able to counter the biofilm formation in a titanium cylinder under the tested condition. In conclusion, our dental implant model may be useful for exploring probiotic-pathogen interaction to find an alternative to antibiotics for peri-implantitis treatment.