Colony-forming Units Per Milliliter Research Articles

Urinary calprotectin as a diagnostic tool for detecting significant bacteriuria

Pyuria in dipstick examination serves as the most widespread screening tool for urinary tract infections (UTI). The absence of pyuria, however, does not exclude UTI. We investigated the diagnostic value of urinary calprotectin, a mediator protein of the innate immune system, which is released by leukocytes, for the detection of UTI and compared it with dipstick pyuria. Since even low numbers of leukocytes in the urine significantly increase urinary calprotectin concentrations, calprotectin might be a more sensitive marker than pyuria detected by dipstick. All 162 patients were prospectively included and underwent a urine dipstick, urine culture, quantification of proteinuria and determination of calprotectin in the urine. Urinary calprotectin was determined using an enzyme-linked immunosorbent assay (ELISA). UTI was defined as urine cultures with detection of one or a maximum of two uropathogenic bacteria with ≥ 105 colony-forming units per millilitre (CFU/ml). Exclusion criteria were acute kidney injury, chronic renal insufficiency and tumors of the urinary tract. 71 (43.8%) patients had a UTI. Of the 91 patients without UTI, 23 had a contamination and 19 had evidence of ≥ 105 CFU/ml considered to be asymptomatic bacteriuria. The median calprotectin concentration in patients with UTI and pyuria was significantly higher than in patients with UTI and without pyuria (5510.4 vs. 544.7 ng/ml). In ROC analyses, calprotectin revealed an area under the curve (AUC) of 0.70 for the detection of significant bacteriuria. Pyuria in dipstick examinations provided an AUC of 0.71. There was no significant difference between these AUCs in the DeLong test (p = 0.9). In patients with evidence of significant bacteriuria but without pyuria, a significantly higher calprotectin concentration was measured in the urine than in patients with neither pyuria nor UTI (544.7 ng/ml vs 95.6 ng/ml, p = 0.029). Urinary calprotectin is non-inferior to dipstick pyuria in the detection of UTI.

Analysis and Modification of a Colorimetric Nanosensor for Rapid Detection of Escherichia coli in Water

This research analyzed the mechanisms of work and modified a colorimetric nanosensor to make it more cost-effective for the detection of Escherichia coli (E. coli) in water. The base nanosensors modified herein rely on a competitive binding detection mechanism, where positively charged gold nanoparticles coated with polyethyleneimine (PEI-AuNPs) preferably bind to negatively charged E. coli in the presence of β-galactosidase (β-Gal) enzymes and chlorophenol red β-d-galactopyranosides (CPRG). The positive surface charge of the nanoparticle, rather than nanoparticle composition or type of chemical coating on its surface, was hypothesized herein as the governing factor for the nanosensor functionality. Thus, positively charged nanoparticles and polymers were tested as potential alternatives for gold nanoparticles for detecting E. coli. Positively charged silver and iron oxide nanoparticles coated with branched PEI detected E. coli as low as 105 and 107 colony-forming units per milliliter (CFU/mL), respectively. Furthermore, the branched PEI polymer itself (without nanomaterial) detected E. coli at 107 CFU/mL. These findings suggest that the positive charge, rather than the nanoparticle type was likely responsible for the detection of E. coli using the competitive binding approach. Therefore, other types of recyclable and cost-effective nanomaterials and polymers can be developed for E. coli detection using this rapid colorimetric sensing technique.

Silver vanadate nanomaterial incorporated into heat-cured resin and coating in printed resin - Antimicrobial activity in two multi-species biofilms and wettability

ObjectivesTo incorporate the nanostructured silver vanadate decorated with silver nanoparticles (AgVO3) into denture base materials: heat-cured (HC) and 3D printed (3DP) resins, at concentrations of 2.5 %, 5 %, and 10 %; and to evaluate the antimicrobial activity in two multi-species biofilm: (1) Candida albicans, Candida glabrata, and Streptococcus mutans, (2) Candida albicans, Pseudomonas aeruginosa, and Staphylococcus aureus, and the wettability. MethodsThe AgVO3 was added to the HC powder, and printed samples were coated with 3DP with AgVO3 incorporated. After biofilm formation, the antimicrobial activity was evaluated by colony forming units per milliliter (CFU/mL), metabolic activity, and epifluorescence microscopy. Wettability was assessed by the contact angles with water and artificial saliva. ResultsIn biofilm (1), HC-5 % and HC-10 % showed activity against S. mutans, HC-10 % against C. glabrata, and HC-10 % and 3DP-10 % had higher CFU/mL of C. albicans. 3DP-5 % had lower metabolic activity than the 3DP control. In biofilm (2), HC-10 % reduced S. aureus and P. aeruginosa, and HC-5 %, 3DP-2.5 %, and 3DP-5 % reduced S. aureus. 3DP incorporated with AgVO3, HC-5 %, and HC-10 % reduced biofilm (2) metabolic activity. 3DP-5 % and 3DP-10 % increased wettability with water and saliva. ConclusionHC-10 % was effective against C. glabrata, S. mutans, P. aeruginosa, and S. aureus, and HC-5 % reduced S. mutans and S. aureus. For 3DP, 2.5 % and 5 % reduced S. aureus. The incorporation of AgVO3 into both resins reduced the metabolic activity of biofilms but had no effect on C. albicans. The wettability of the 3DP with water and saliva increased with the addition of AgVO3. Clinical SignificanceThe incorporation of silver vanadate into the denture base materials provides antimicrobial efficacy and can prevent the aggravation of oral and systemic diseases. The incorporation of nanomaterials into printed resins is challenging and the coating is an alternative to obtain the inner denture base with antimicrobial effect.

Yenidoğanlarda Uzamış Sarılıkta İdrar Yolu Enfeksiyonunun Sıklığı ve Rolü

Objective: The study aims to investigate the frequency and role of urinary tract infection (UTI) in prolonged jaundice in preterm and term neonates.
 Materials and Methods: This retrospective study occurred at Zeynep Kamil Maternity and Children's Hospital in Istanbul between January 2014 and April 2018. The study involved 391 neonates who presented to our outpatient clinics with prolonged jaundice. UTI was defined as urine culture growth of at least 10.000 colony-forming units per millilitre (CFU/ml) in samples obtained via urethral catheterization. Birth weight, sex, gestational age, chronological age, laboratory results, hospital courses of patients, ultrasound findings and phototherapy history were recorded. 
 Results: UTI frequency was found to be 2.8% in 391 neonates with prolonged jaundice. Nine of them were male (81.8%), and 2 were female (18.2%). Eight patients with UTI (72.7%) were term and 3 (29.3%) were preterm. History of phototherapy, presence of leukocyturia or nitrituria, white blood cell count, and thrombocyte counts were significantly higher in the UTI group.
 Conclusion: Prolonged jaundice may be the first sign of UTI in neonates. Routine urine culture in neonates with prolonged jaundice may be useful, especially in those with a history of phototherapy and high white blood cell and thrombocyte counts.

Antimicrobial photodynamic effect of the photosensitizer riboflavin, alone and in combination with colistin, against pandrug-resistant Pseudomonas aeruginosa clinical isolates

IntroductionDevelopment of multi-, extensively-, and pandrug-resistant (MDR, XDR, and PDR) strains of Pseudomonas aeruginosa remains a major problem in medical care. The present study evaluated the effect of antimicrobial photodynamic therapy (aPDT) as a monotherapy and in combination with colistin against P. aeruginosa isolates. MethodsTwo P. aeruginosa isolates recovered from patients with respiratory tract infections were examined in this study. Minimum inhibitory concentration (MIC) of colistin was determined by the colistin broth disk elution (CBDE) and the reference broth microdilution (rBMD) methods. aPDT was performed using the photosensitizer (Ps) riboflavin at several concentrations and a light-emitting diode (LED) emitting blue light for different irradiation times with or without colistin at 1/2 × MIC concentration. ResultsBoth PA1 and PA2 isolates were identified as colistin-resistant P. aeruginosa with a MIC ≥4 μg/mL by the CBDE and MICs of 512 μg/mL and 256 μg/mL, respectively, by the rBMD. In aPDT, neither riboflavin nor LED light alone had antibacterial effects. The values of colony forming units per milliliter (CFU/mL) in both isolates were significantly reduced by LED + Ps treatments in a time-dependent manner (LED irradiation time) and dose-dependent manner (Ps concentration). In comparison with control, treatment with Ps (50 μM) + LED (120 s) and Ps (100 μM) + LED (120 s) resulted in 0.27 log10 CFU/mL and 0.43 log10 CFU/mL reductions in PA1, and 0.28 log10 CFU/mL and 0.34 log10 CFU/mL reductions in PA2, respectively, (P < 0.01). The best results were obtained after the combination of aPDT followed by colistin, which increased bacterial reduction, resulting in a 0.41−0.7 log10 CFU/mL reduction for PA1 and 0.35−0.83 log10 CFU/mL reduction for PA2 (P = 0.001). Conclusions: This study suggests the potential implications of aPDT in combination with antibiotics, such as colistin for treatment of difficult-to-treat P. aeruginosa infections.

Antibacterial Effect of Two Novel Sealants: A Laboratory-Based Study.

This research sought to assess the impact of polyhexamethylene guanidine hydrochloride (PHMGH) and 1,3,5-triacryloyl hexahydro-1,3,5-triazine (TAT) on the antibacterial activity of an experimental resin sealant. The two experimental sealants were formulated based on previous research, and Streptococcus mutans (S. mutans) was tested for biofilm and planktonic bacteria's antibacterial properties. In 48 hours, 300 L of frozen S. mutans in skim milk was stored in an oven at 37°C in a microaerophilic atmosphere with 5% of CO2 and put on a petri plate containing brain-heart infusion (BHI) broth with agar at 15 g/L. By combining 100 mL of the subculture broth with 900 mL of a sterile saline solution (0.9%) in an Eppendorf tube, the initial inoculum used for the experiments was evaluated. The colonies were measured in colony-forming units per milliliter (CFU/mL) after being counted visually. To measure the antibacterial activity, log CFU/mL was used to express the number of bacteria in the broth that had been in contact with the samples for 24 hours. Outcomes of antibacterial activity against planktonic bacteria and against biofilm development on polymerized materials. The two innovative sealant materials were found to differ significantly from one another, while group 2's mean and standard deviation values were larger. Dental sealants designed with PHMGH and TCPTAT for anticaries application showed less bacterial growth throughout time the cavity prevention properties of the resin sealant.

Improving antibacterial ability of Ti-Cu thin films with co-sputtering method

Due to the resistance of some bacteria to antibiotics, research in the field of dealing with bacterial infections is necessary. A practical approach utilized in this study involves the preparation of an antibacterial thin film on the surfaces, which can effectively inhibit and reduce biofilm formation and bacterial adherence. In this study, we report the fabrication of bactericidal titanium (Ti) and copper (Cu) surfaces which involves a powerful co-sputtering method. This method provides a situation in which constituent elements are deposited simultaneously to control the composition of the thin film. Prepared samples were examined by energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), X-ray diffraction (XRD), atomic force microscopy (AFM), and contact angle measurements. To evaluate antibacterial behavior, we used two bacterial strains Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus). Antibacterial activity of the prepared sample was assessed by determining the number of colony-forming units per milliliter (CFU/ml) using a standard viable cell count assay. Results indicated that as the Cu concentration increased, the nanoscale surfaces became rougher, with roughness values rising from 11.85 to 49.65 nm, and the contact angle increased from 40 to 80 degrees, indicating a hydrophilic character. These factors play a significant role in the antibacterial properties of the surface. The Ti-Cu films displayed superior antibacterial ability, with a 99.9% reduction (equivalent to a 5-log reduction) in bacterial viability after 2 h compared to Ti alone against both bacterial strains. Field emission scanning electron microscopy (FE-SEM) images verified that both E. coli and S. aureus cells were physically deformed and damaged the bacterial cell ultrastructure was observed. These findings highlight that adding Cu to Ti can improve the antibacterial ability of the surface while inhibiting bacterial adherence. Therefore, the Ti14-Cu86 sample with the highest percentage of Cu had the best bactericidal rate. Investigation of toxicity of Cu-Ti thin films was conducted the using the MTT assay, which revealed their biocompatibility and absence of cytotoxicity, further confirming their potential as promising biomaterials for various applications.

Effects of Different Types of Probiotics on Microbial Colonization in Saliva of Orthodontic Patients—In Vivo Study

Introduction Streptococcus mutans and Lactobacillus count is found to be higher in orthodontic patients and is one of the leading causes of white spot lesion formation. Probiotics are emerging as alternative methods of plaque control. Aims and Objectives To determine the effects of different types of probiotics on S. mutans and Lactobacillus levels in saliva of orthodontic patients. Materials and Methods A total of 140 subjects were divided into Control group (Group I) with 20 subjects and study group taking probiotics (Group II) with 120 subjects. Saliva samples were taken at baseline ( T0), after three weeks ( T1), and after six weeks ( T2). The samples were diluted and incubated on specific agar media plates. The colonies observed were expressed in colony forming units per milliliter (CFU/ml) of saliva. Group II was further subdivided into six subgroups based on probiotic intake with 20 subjects in each subgroup. Results Statistically significant difference was found in salivary microbial counts in all the probiotic groups ( p &lt; 0.05). The highest reduction in count of S. mutans (653.00 ± 102.23 CFU/ml to 84.1 ± 30.48 CFU/ml) and Lactobacilli (87.35 ± 15.64 CFU/ml to 14.60 ± 8.28 CFU/ml) was seen in the lozenges group. Conclusion Probiotics decrease the number of salivary S. mutans and Lactobacilli and lozenges could be considered for orthodontic fixed appliance patients.

Antibacterial Effect of Combinations of Salvia officinalis and Glycyrrhiza glabra Hydroalcoholic Extracts against Enterococcus spp.

Enterococcus spp. are a common culprit behind the failure of endodontic treatments, primarily due to their notorious resistance to antimicrobial agents. Considering this challenge, this study was conducted to assess the antimicrobial efficacy of a unique blend of hydroalcoholic extracts sourced from Salvia officinalis and Glycyrrhiza glabra against biofilms formed by Enterococcus faecalis and Enterococcus faecium. The chemical composition of these plant extracts was rigorously characterized, with primary compound quantification achieved through high-performance liquid chromatography (HPLC-DAD) analysis. Additionally, this study determined the minimal bactericidal concentrations of these extracts and evaluated their potential to combat biofilms by quantifying colony-forming units per milliliter (CFU/mL). The findings reveal that the simultaneous application of both extracts yielded additive and synergistic effects against E. faecalis and E. faecium, including both ATCC and clinical strains. Impressively, after a 24 h exposure, these extract combinations demonstrated efficacy comparable to that of a 0.12% chlorhexidine solution, establishing a statistically significant difference from the negative control group. Consequently, the concurrent use of these extracts emerges as a promising alternative antimicrobial strategy for addressing Enterococcus spp. in endodontic treatments, holding substantial potential for clinical applications in this context.

Polyhexamethylene guanidine hydrochloride as promising active ingredient for oral antiseptic products to eliminate microorganisms threatening the health of endangered wild cats: a comparative study with chlorhexidine digluconate.

The aim of this study was to evaluate the antimicrobial efficacy of polyhexamethylene hydrochloride guanidine (PHMGH) compared to chlorhexidine digluconate (CLX) for use as an oral antiseptic during dental procedures in wild cats. This research is crucial due to limited information on the diversity of oral microorganisms in wild cats and the detrimental local and systemic effects of oral diseases, which highlights the importance of improving prevention and treatment strategies. Samples were collected from the oral cavities of four Puma concolor, one Panthera onca, and one Panthera leo, and the number of colony-forming units per milliliter (CFU/mL) was counted and semi-automatically identified. The antimicrobial susceptibility profile of bacterial isolates was determined using minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and time-kill kinetics of PHMGH and CLX. A total of 16 bacterial isolates were identified, consisting of six Gram-positive and 10 Gram-negative. PHMGH displayed MIC and MBC from 0.24 to 125.00 μg/mL, lower than those of CLX against three isolates. Time-kill kinetics showed that PHMGH reduced the microbial load by over 90% for all microorganisms within 30 min, whereas CLX did not. Only two Gram-positive isolates exposed to the polymer showed incomplete elimination after 60 min of contact. The results could aid in the development of effective prevention and treatment strategies for oral diseases in large felids. PHMGH showed promising potential at low concentrations and short contact times compared to the commercial product CLX, making it a possible active ingredient in oral antiseptic products for veterinary use in the future.

Probiotics mitigate kidney damage after exposure to Sri Lanka's local groundwater from chronic kidney disease with uncertain etiology (CKDu) prevalent area in zebrafish

Groundwater in Sri Lanka, contaminated with environmental toxins, is suspected to potentially induce chronic kidney disease of uncertain etiology (CKDu) in humans. This study aims to elucidate the potential mitigating effects of probiotics on kidney damage induced by exposure to this local groundwater (LW) in zebrafish. We used zebrafish as a model organism and exposed them to local groundwater to evaluate the risk of CKDu. Probiotics were then added at a concentration of 108 colony-forming units per milliliter (CFU/mL). Our findings revealed that exposure to local groundwater resulted in abnormalities, such as tail deletion and spinal curvature in zebrafish larvae. However, the addition of probiotics mitigated these effects, improving the hatching rate, heart rate, length, weight, deformity rate, survival rate, and abnormal behavior of zebrafish. It also positively influenced the differential expression levels of kidney development and immunity-related genes (dync2h1, foxj1, pkd2, gata3, slc20a1, il1β, and lyso). Furthermore, exposure to LW decreased both the diversity and abundance of microbiota in zebrafish larvae. However, treatment with probiotics, such as L. plantarum and L. rhamnosus partially restored the disrupted gut microbiota and significantly impacted the cellular process pathways of the microbial community, as determined by KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis. In conclusion, this study highlights the risks associated with Sri Lanka's local groundwater from a CKDu prevalent area and confirms the beneficial effects of different probiotics. These findings may provide new insights into bacterial function in host kidney health.

Toward the Real-Time and Rapid Quantification of Bacterial Cells Utilizing a Quartz Tuning Fork Sensor.

The quantitative evaluation of bacterial populations is required in many studies, particularly in the field of microbiology. The current techniques can be time-consuming and require a large volume of samples and trained laboratory personnel. In this regard, on-site, easy-to-use, and direct detection techniques are desirable. In this study, a quartz tuning fork (QTF) was investigated for the real-time detection of E. coli in different media, as well as the ability to determine the bacterial state and correlate the QTF parameters to the bacterial concentration. QTFs that are commercially available can also be used as sensitive sensors of viscosity and density by determining the QTFs' damping and resonance frequency. As a result, the influence of viscous biofilm adhered to its surface should be detectable. First, the response of a QTF to different media without E. coli was investigated, and Luria-Bertani broth (LB) growth medium caused the largest change in frequency. Then, the QTF was tested against different concentrations of E. coli (i.e., 102-105 colony-forming units per milliliter (CFU/mL)). As the E. coli concentration increased, the frequency decreased from 32.836 to 32.242 kHz. Similarly, the quality factor decreased with the increasing E. coli concentration. With a coefficient (R) of 0.955, a linear correlation between the QTF parameters and bacterial concentration was established with a 26 CFU/mL detection limit. Furthermore, a considerable change in frequency was observed against live and dead cells in different media. These observations demonstrate the ability of QTFs to distinguish between different bacterial states. QTFs allow real-time, rapid, low-cost, and non-destructive microbial enumeration testing that requires only a small volume of liquid sample.

Comparison of two swab types for recovery of Staphylococcus aureus and Candida auris from gloves and gowns.

Known concentrations of Staphylococcus aureus and Candida auris were applied on gloves and gowns then sampled with E-swabs and BBL liquid Amies swabs. The mean numbers of colony-forming units per milliliter (CFU/mL) obtained from culture of the 2 swab types were not different, suggesting that either can be used for recovery of these two pathogens from personal protective equipment.

Efficacy and safety of piperacillin-tazobactam compared with meropenem in treating complicated urinary tract infections including acute pyelonephritis due to extended-spectrum β-lactamase-producing Enterobacteriaceae.

Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae pose a huge threat to human health, especially in the context of complicated urinary tract infections (cUTIs). Carbapenems and piperacillin-tazobactam (PTZ) are two antimicrobial agents commonly used to treat cUTIs. A monocentric retrospective cohort study focused on the treatment of cUTIs in adults was conducted from January 2019 to November 2021. Patients with a positive urine culture strain yielding ≥ 103 colony-forming units per milliliter (CFU/mL), and sensitive to PTZ and carbapenems, were included. The primary endpoint was clinical success after antibiotic therapy. The secondary endpoint included rehospitalization and 90-day recurrence of cUTIs caused by ESBL-producing Enterobacteriaceae. Of the 195 patients included in this study, 110 were treated with PTZ while 85 were administered meropenem. The rate of clinical cure was similar between the PTZ and meropenem groups (80% vs. 78.8%, p = 0.84). However, the PTZ group had a lower duration of total antibiotic use (6 vs. 9; p < 0.01), lower duration of effective antibiotic therapy (6 vs. 8; p < 0.01), and lower duration of hospitalization (16 vs. 22; p < 0.01). In terms of adverse events, the safety of PTZ was higher than that of meropenem in the treatment of cUTIs.

Application of survival analysis to model proliferation likelihood of Escherichia coli biofilm following laser-induced hyperthermia treatment.

Eighty percent of bacterial infections associated with living tissue and medical devices are linked to drug-resistant biofilms, leading to lengthy and costly recoveries. Laser-induced hyperthermia can disrupt cell proliferation within biofilms and increase susceptibility to antibiotics. However, there can be bacterial survival differences dependent upon laser irradiation times, and prolonged time at elevated temperature can damage healthy tissue. The objective of this study was to use survival analysis to model the impact of temperature increases on reducing viable biofilm bacteria. In vitro biofilms of Escherichia coli were grown on silicone discs or silicone doped with photothermal poly(3,4-ethylenedioxythiophene) hydrate (PEDOT) nanotubes, and subjected to laser-induced hyperthermia, using a 3W continuous wave laser at 800nm for varying times. The number of colony forming units per milliliter (CFU/mL) and maximum temperature were measured after each trial. Survival analysis was employed to estimate bacterial cell proliferation post-treatment to provide a quantitative framework for future studies evaluating photothermal inactivation of bacterial biofilms. The results demonstrate the first application of survival analysis for predicting the likelihood of bacterial cell proliferation based on temperature.

Adhesion of biofilm, surface characteristics, and mechanical properties of antimicrobial denture base resin.

This study incorporated the nanomaterial, nanostructured silver vanadate decorated with silver nanoparticles (AgVO3), into heat-cured resin (HT) at concentrations of 2.5%, 5%, and 10% and compared the adhesion of multispecies biofilms, surface characteristics, and mechanical properties with conventional heat-cured (HT 0%) and printed resins. AgVO3 was incorporated in mass into HT powder. A denture base resin was used to obtain printed samples. Adhesion of a multispecies biofilm of Candida albicans, Candida glabrata, and Streptococcus mutans was evaluated by colony-forming units per milliliter (CFU/mL) and metabolic activity. Wettability, roughness, and scanning electron microscopy (SEM) were used to assess the physical characteristics of the surface. The mechanical properties of flexural strength and elastic modulus were tested. HT 10%-AgVO3 showed efficacy against S. mutans; however, it favored C. albicans CFU/mL (P < .05). The printed resin showed a higher metabolically active biofilm than HT 0% (P < .05). There was no difference in wettability or roughness between groups (P > .05). Irregularities on the printed resin surface and pores in HT 5%-AgVO3 were observed by SEM. HT 0% showed the highest flexural strength, and the resins incorporated with AgVO3 had the highest elastic modulus (P < .05). The incorporation of 10% AgVO3 into heat-cured resin provided antimicrobial activity against S. mutans in a multispecies biofilm did not affect the roughness or wettability but reduced flexural strength and increased elastic modulus. Printed resin showed higher irregularity, an active biofilm, and lower flexural strength and elastic modulus than heat-cured resin.

Antibacterial Effect of Miswak herbal toothpaste Compared to Fluoride Toothpaste in High Caries Risk Patients: Randomized Clinical Trial.

Modern toothbrushes origin can be traced to plant-derived chewing sticks, which were documented to be used Babylonians as early as 3500 BC. Chewing sticks are routinely used for cleaning teeth in Asia, Africa, South America, and the Middle East. The aim of the current study was to evaluate the antibacterial effect of miswak herbal toothpaste compared to fluoride toothpaste using a normal toothbrush, against Streptococcus mutans in high caries risk patients. A total of 32 participants were recruited to the current clinical trial using convenience sampling randomly either to miswak or fluoride toothpastes groups (n=16). The bacterial count represented as colony-forming units per milliliter (CFU/ml) was assessed at baseline and after 1 week, 1 month and 3 months. Moreover, the ion release for silicone, calcium, phosphorus, and fluoride from both toothpastes was analyzed in addition to the pH of both toothpastes and their supernatants. Intergroup comparison was performed using independent t test, while intragroup comparison was performed using repeated measures ANOVA followed by tukey post-hoc test and paired t test when appropriate. There was no statistically significant difference between both toothpastes for the S. mutans count within each follow up period, however the bacterial count significantly decreased over time in both groups. Signal Fluoride toothpaste exhibited statistically significant higher ion release when compared to the Dabur Miswak toothpaste. There was no statistically significant difference between either toothpastes regarding pH (P = 0.5368), while comparison between supernatants of toothpastes have shown statistically significant difference (P = 0.0194), with a higher pH in miswak toothpaste. Miswak herbal toothpaste possesses a potent antibacterial effect, yet its remineralization potential is questionable due to its inferior ion release that will affect the ion substantivity in saliva, which is an important factor in remineralization. Key words:High caries risk, Miswak, Fluoride, Antibacterial, Streptococcus mutans.

Biofilm elimination from infected root canals using four different single files

IntroductionEnterococcus faecalis (E. faecalis) is the most commonly isolated bacterium from infected root canals. It is found in the form of a biofilm, which makes it more resistant to antimicrobials, and requires optimal chemomechanical strategies to maximize root canal disinfection.AimTo evaluate the efficacy of 4 different endodontic file systems against E. faecalis biofilm growth in root canals using colony-forming units per milliliter (CFU/mL) and scanning electron microscope (SEM).MethodsEighty-five extracted human mandibular premolars with straight root canals and apical diameters not larger than the #15 K-file were randomly selected. After performing a pilot study (n = 15) to determine the ideal incubation period for E. faecalis biofilm development, sixty-five root canals were infected with E. faecalis, incubated for 3 weeks, and then mechanically prepared using one of four single files (XP-endo Shaper, Hyflex EDM, One Curve, and Fanta. AFTM F One) (n = 15). Five infected root canals were excluded for the positive control. Five non-contaminated root canals were included for the negative control. Samples were collected using sterile paper points pre- and post-instrumentation to determine the bacterial load (CFU/mL). Root canals from each group were topographically evaluated at the coronal, middle, and apical segments using scanning electron microscope (SEM). Bacterial reduction data were estimated and statistically analyzed by Kruskal–Wallis and Mann–Whitney U tests (post hoc test) (P ≤ .05).ResultsXP-endo Shaper, Hyflex DEM, and One Curve significantly could eradicate E. faecalis biofilms in infected root canals with no significant difference among them compared to Fanta. AF™ F One.ConclusionNone of the systems were capable of completely eliminating biofilms. XP-endo Shaper, Hyflex EDM, and One Curve mechanically eliminated E. faecalis biofilms compared to Fanta. AF™ F One from infected root canals.

Assessment of Keratitis Severity Using Quantitative Image Analysis in an In Vivo Murine Model of Staphylococcus aureus Bacterial Keratitis.

Bacterial keratitis (BK) severity in murine models has traditionally been measured by subjective clinical grading or quantification of ocular bacterial burden. This investigation explores an objective and repeatable quantification of slit lamp photography (SLP) images to measure BK severity. BALB/c strain mice underwent three parallel scratches of the right cornea with subsequent inoculation of 107Staphylococcus aureus cells. SLP imaging and clinical severity grading were performed at 48 hours post-infection. Stromal infiltrate (SI) area on SLP images were quantified. Bacterial burden was determined after enucleation and homogenization. Spearman rank correlations (rs) were used to estimate associations between SI area, clinical severity grades, and bacterial burden. BALB/c strain mice (n = 14) were evaluated with an average SI area of 0.92 mm2 (standard deviation, SD = 0.65) and average bacterial burden of 3.16 × 105 colony forming units per milliliter (CFU/mL) (SD = 8.3 × 105). Clinical severity grade positively correlated with SI area (rs = 0.59, p = 0.0276) and bacterial burden (rs = 0.66, p = 0.0106). There was a trend towards positive association between SI area and bacterial burden (rs = 0.51, p = 0.0543). SLP annotation of SI area is correlated with clinical severity and may provide an objective, quantitative, and repeatable assessment of BK disease severity. SLP annotation of SI area is a novel quantitative method to evaluate bacterial keratitis severity longitudinally in mouse models which may be a powerful tool to better understand BK pathogenesis and response to treatments.

Native Bacillus subtilis Strains Efficiently Control Lupin Anthracnose Both under Greenhouse and in Field Conditions

Colletotrichum acutatum is the cause of lupin anthracnose in the Andean zone. The pathogen affects the crop throughout its entire production cycle, causing losses of up to 100%. In previous studies, native strains of B. subtilis (CtpxS1-1; CtpxS2-1 and CtpxZ3) from the province of Cotopaxi reduced anthracnose infections in seed and seedlings. This study evaluated the potential biological control of these strains by using two lupin anthracnose susceptible cultivars under greenhouse conditions and in the field. Plants of I-451 Güaranguito and I-450 Andino cultivars were treated with active biomass from each B. subtilis strain. Pre-inoculated plants that received a bacterial concentration of 1 × 109 colony-forming units per milliliter (CFU/ml) showed a reduction by ten times in the stem lesion diameter when compared with plants artificially infected with the pathogen alone in greenhouse evaluations. Sequential applications of antagonists every two-week allow for quantifying their biocontrol efficiency under field conditions. A significant (P