Blood Agar Plates Research Articles

Nanoparticles on pathogenic strains of Staphylococcus aureus and Escherichia coli

Background: Nanoparticles are increasingly being used as an alternative antibiotic to target microorganisms, particularly for treating bacterial infections. In current study it was recognized processes such as metal ion release, induction of oxidative stress, and non-oxidative mechanisms. Developing resistance to nanoparticles is challenging for bacterial cells due to the multiple simultaneous actions against microorganisms, and require several simultaneous gene alterations within the same bacterial cell. Objective: To determine the effect of the titanium dioxide nanoparticles (TiO2NPs) on the activity of the same bacteria that participate in dental caries (Staphylococcus aureus and Escherichia coli). Patients and Methods: The study included 50 patients who attended the dental clinic and took the samples by the wooden swap from the molar area (cervical area of inflamed gingiva and same samples taken from occlusal surface of molar). The collected samples were cultured on “Mannitol salt agar, Blood agar, and MacConkey's agar plates” for separation of the needed bacteria (Staphylococcus aureus and Escherichia coli) that showed wide spreading in the oral cavities and dental carries. TiO2NPs are then created using pulse laser ablation, followed by coating preparation the nanoparticles materials (using a hybrid sol-gel and organ silicate nanoparticles), and finally the prepared nanoparticles to the coating solution and local paint were used for antimicrobial activity of the separated bacteria using different concentrations of TiO2 in the cultures. Results: Characterization showed the phase of the TiO2NPs was spherical, with very few irregularly shaped particles, and had an average small size in millimeters. Antimicrobial activity results showed a strong bactericidal effect against Gram-positive bacteria and demonstrated greater sensitivity to TiO2 nanoparticles at lower concentrations when compared to Gram-negative bacteria. Conclusion: It was shown that nanotechnology promise in treating various infections caused by bacteria, including dental caries. Notably, nanoparticles have demonstrated broad-spectrum antibacterial effects against Gram-positive bacteria. Keywords: TiO2, nanoparticles, Staphylococcus aureus, and E. coli

Electron Microscope Scanning, and Antibacterial Activity of Tio2 Nanoparticles on pathogenic strains of Staphylococcus aureus and Escherichia coli

Background: Nanoparticles are increasingly being used as an alternative antibiotic to target microorganisms, particularly for treating bacterial infections. In current study it was recognized processes such as metal ion release, induction of oxidative stress, and non-oxidative mechanisms. Developing resistance to nanoparticles is challenging for bacterial cells due to the multiple simultaneous actions against microorganisms, and require several simultaneous gene alterations within the same bacterial cell. Objective: To determine the effect of the titanium dioxide nanoparticles (TiO2NPs) on the activity of the same bacteria that participate in dental caries (Staphylococcus aureus and Escherichia coli). Patients and Methods: The study included 50 patients who attended the dental clinic and took the samples by the wooden swap from the molar area (cervical area of inflamed gingiva and same samples taken from occlusal surface of molar). The collected samples were cultured on “Mannitol salt agar, Blood agar, and MacConkey's agar plates” for separation of the needed bacteria (Staphylococcus aureus and Escherichia coli) that showed wide spreading in the oral cavities and dental carries. TiO2NPs are then created using pulse laser ablation, followed by coating preparation the nanoparticles materials (using a hybrid sol-gel and organ silicate nanoparticles), and finally the prepared nanoparticles to the coating solution and local paint was used for antimicrobial activity of the separated bacteria using different concentrations of TiO2 in the cultures. Results: Characterization showed the phase of the TiO2NPs was spherical, with very few irregularly shaped particles, and had an average small size in millimeters. Antimicrobial activity results showed a strong bactericidal effect against Gram-positive bacteria and demonstrated greater sensitivity to TiO2 nanoparticles at lower concentrations when compared to Gram-negative bacteria. Conclusion: It was shown that nanotechnology promise in treating various infections caused by bacteria, including dental caries. Notably, nanoparticles have demonstrated broad-spectrum antibacterial effects against Gram-positive bacteria.

Hygiene practices and antibiotic resistance among dental and medical students: a comparative study.

Healthcare students' hand and smartphone hygiene is critical due to potential pathogenic and antibiotic-resistant bacteria transmission. This study evaluates hygiene practices in medical and dental students at Kuwait University, exploring antibiotic resistance gene prevalence. Swab samples were collected from the hands and smartphones of 32 medical and 30 dental students. These samples were cultured on Columbia Blood Agar and McConkey Agar plates to quantify bacterial colony-forming units (CFUs). The extracted DNA from these colonies underwent RT-PCR to identify antibiotic resistance genes, including tem-1, shv, blaZ, and mecA. Additionally, a questionnaire addressing hygiene practices was distributed post-sample collection. Medical students exhibited more frequent hand hygiene compared to dental students (P ≤ 0.0001). Although significantly fewer bacterial CFUs were found on medical students' smartphones (mean = 35 ± 53) than dental students' (mean = 89 ± 129) (P ≤ 0.05), no significant differences were observed in CFU counts on their hands (medical: mean = 17 ± 37; dental: mean = 96 ± 229). Detection of at least one of the targeted antibiotic resistance genes on medical (89% hands, 52% smartphones) and dental students' (79% hands, 63% smartphones) was not statistically significant. However, the prevalence of two genes, tem-1 and shv, was significantly higher on medical students' hands (78% and 65%, respectively) than on dental students' hands (32% and 28%, respectively). Clinically significant prevalence of antibiotic resistance genes were found on medical and dental students' hands and smartphones, emphasizing the importance of ongoing education regarding hand hygiene and smartphone disinfection. This continuous reinforcement in the curriculum is crucial to minimizing the risk of cross-contamination.

Bacterial Flora and Treatment Strategies in Women With Escherichia coli Urinary Tract Infections.

Introduction This study explores the intricate relationship between bacterial flora and the occurrence of Escherichia coli (E. coli) infections in gynecological patients. It aims to provide insights into the various treatment strategies used to effectively manage bacterial pathogens, especially E. coli infections. By conducting a comprehensive analysis of the bacterial flora in gynecological patients, the study highlights the notable presence of E. coli, promptingfurther investigation into the factors that contribute to its colonization. The objective of the study is to comprehensively investigate and detect urinary tract infections (UTIs) specifically caused by E. coli among gynecological patients. The study aims to delve into bacterial flora prevalence, antibiotic resistance patterns, and potential virulence factors. Through this analysis, the study intends to identify effective strategies for rapid detection and diagnosis of UTIs caused by E. coliby utilizing advanced microbiological and molecular techniques. Furthermore, the study aims to formulate and propose a strategic treatment approach with a particular emphasis on selecting appropriate antibiotics to reduce the risk of severe infections and associated complications. Materials and methods The methodology employed in this study included the isolation and characterization of bacterial strains from clinical samples obtained from gynecological patients. A total of 52 urine specimens were collected from patients with complaints of infection in the urinary tract and infertility. These samples underwent both preliminary and confirmatory microbiological analysis, such as gram staining, biochemical confirmation test, and antibiotic susceptibility, and further proceeded with the multiplex polymerase chain reaction (PCR) technique. The results of PCR and antibiotic susceptibility revealed the specific gene involvement and resistant characteristics of E. coli. Results The findings revealed a total of 32 specimens positive for E. coli, of which 10 patients had infertility complaints and 22 patients had UTIs. The preliminary test, gram staining, showed the gram-negative bacilli E. coli, and the nutrient agar plate revealed smooth circular translucent colonies; MacConkey agar showed pink-colored lactose-fermented colonies; and the blood and chocolate agar plates showed grayish white moist gamma-hemolytic colonies. The biochemical confirmation of E. coli resulted in positive for indole and methyl red tests and negative for Voges-Proskauer and citrate utilization tests. The multiplex PCR analysis confirmed the E. coli strains with the presence of two target genes,stx2d and stx2e. Conclusion To summarize, this study offers valuable insights into the bacterial flora of gynecological patients impacted by E. coli infections, which provides a foundation for the development of precise and efficient treatment strategies. The results emphasize the importance of personalized treatment approaches that consider both the microbiological characteristics of the infection and the evolving landscape of antibiotic resistance. The implication of this research extends to enhancing clinical outcomes and alleviating the burden of E. coli infections in gynecological settings.

Isolation, Identification, and Characterization of Bacillus cereus Group Bacteria Isolated from the Dairy Farm Environment and Raw Milk in Tunisia.

Members of the Bacillus cereus group are well-known opportunistic foodborne pathogens. In this study, the prevalence, hemolytic activity, antimicrobial resistance profile, virulence factor genes, genetic diversity by enterobacterial repetitive intergenic consensus (ERIC)-polymerase chain reaction (PCR) genotyping, and adhesion potential were investigated in isolates from a Tunisian dairy farm environment and raw milk. A total of 200 samples, including bedding, feces, feed, liquid manure, and raw bovine milk, were examined. Based on PCR test targeting sspE gene, 59 isolates were detected. The prevalence of B. cereus group isolates in bedding, feces, liquid manure, feed, and raw milk was 48%, 37.8%, 20%, 17.1%, and 12.5%, respectively. Out of the tested strains, 81.4% showed β-hemolytic on blood agar plates. An antimicrobial resistance test against 11 antibiotics showed that more than 50% of the isolates were resistant to ampicillin and novobiocin, while a high sensitivity to other antibiotics tested was observed in most isolates. The distribution of enterotoxigenic genes showed that 8.5% and 67.8% of isolates carried hblABCD and nheABC, respectively. In addition, the detection rate of cytotoxin K (cytk), enterotoxin T (bceT), and ces genes was 72.9%, 64.4%, and 5.1%, respectively. ERIC-PCR fingerprinting genotype analysis allowed discriminating 40 different profiles. The adhesion potential of B. cereus group on stainless steel showed that all isolates were able to adhere at various levels, from 1.5 ± 0.3 to 5.1 ± 0.1 log colony-forming unit (CFU)/cm2 for vegetative cells and from 2.6 ± 0.4 to 5.7 ± 0.3 log CFU/cm2 for spores. An important finding of the study is useful for updating the knowledge of the contamination status of B. cereus group in Tunisia, at the dairy farm level.

Hyaluronic acid-based gels for oral application: Comparison of in vitro effects on gingival cells and bacteria

PurposeThis study aimed to evaluate the cytotoxic effects of different topical hyaluronic acid-based gels on human gingival fibroblasts and oral bacteria. MethodsFour different hyaluronate gels - Bexident® Aftas (BA), GUM® AftaClear (AfC), Gengigel®(G), Aloclair® Plus (AlC) and a chlorhexidine gel - Bexident®Gums(BG) were selected. Human gingival fibroblasts (HGF) were seeded in 48-well plates with different gel/culture medium concentrations (v/v%) and cell viability was evaluated at 1 and 3 days of culture. Cell morphology was assessed, and alterations graded according to ISO 10993–5:2009(E). Streptococcus oralis CECT 907T colony was, seed on 48-well plate or spread onto the blood agar plates and exposed to the different gel's concentration. The optical density (OD) was assessed, and the diameter of the inhibition zone was measured (mm). ResultsBA and G elicited reduced HGF cytotoxicity, followed by AfC. AlC and BG were cytotoxic at concentrations up to 3% for all exposure times. PCM images of HGF showed moderate-to-severe alterations for AlC and BG and slight to mild changes, for BA, AfC and G. The highest antibacterial activity against S.oralis was observed on AlC and AfC, and no antibacterial activity was observed for BA and G. Inhibitory effect in sessile colonies was only observed in AlC and BG. ConclusionsAlC demonstrated superior antibacterial activities against S.oralis but a higher cytotoxic potential in HGF. BA and G presented the lowest cytotoxicity with little to no antibacterial effect. AfC demonstrated bacteriostatic effects and low cytotoxicity on HGF.

The Use of Microbiological Quality Control Techniques Adopted in a Human Tissue Bank

The Brazilian Ministry of Health’s Consolidation Ordinance No. 4 of September 28, 2017, provides the requisites for the evaluation of services for human tissue banks (bancos de tecidos humanos [BTH]) in terms of the microbiological control of environments (ISO 5 classification processing room) and products (culture for aerobic, anaerobic, and fungal pathogens), with a view to guaranteeing harmlessness in tissue transplants. Objectives: To highlight the techniques for microbiological control of distributed tissues adopted by a BTH over 5 years, as well as the results obtained from the application and use of these techniques. Methods: Using standard operating procedures (SOPs), the methodology, and frequency of collections, tests and room cleaning were established in advance. Microbiological cultures were taken from the tissues during all the collections and processing. During tissue processing, fingerprint samples on the processor’s gloves and in the processing room were seeded on blood agar plates. The processing room was cleaned weekly with biguanide and quaternary ammonium. The processing bench was sanitized with sterile 70% alcohol and the microbiological environmental control was carried out every 6 months by a qualified outsourced company. Results: In the period analyzed, the techniques proved effective in 46 (96%) cases, with contamination identified in only two (4%) processed and collected samples. The effectiveness and results were documented. Conclusion: Effective biological quality control methods are legitimately required, but they can be improved, raising the need to develop safe protocols for the quality of services and the safety of transplanted tissues.

Investigation of Uropathological Bacterial Profile and Antibiotic Susceptibility Patterns Among Pregnant Women in Rawalpindi and Islamabad: A Comprehensive Analysis

Background: Urinary tract infections (UTIs) represent a significant health concern for pregnant women, potentially leading to adverse outcomes for both mother and child. The anatomical and physiological changes during pregnancy increase the risk of UTIs, making the study of their bacteriological profile and antibiotic susceptibility patterns especially pertinent. Objective: This study aimed to assess the bacteriological profile and antibiotic susceptibility patterns of UTIs among pregnant women in Rawalpindi and Islamabad, to identify the most prevalent pathogens and their resistance to commonly used antibiotics. Methods: A cross-sectional study was conducted on 165 early morning mid-stream urine samples collected from pregnant women attending the Railway General Hospital, Rawalpindi, over four months. Samples were analyzed for UTI-causing organisms using Cysteine Lactose Electrolyte Deficient (CLED) medium, MacConkey agar, and blood agar plates. Gram staining and biochemical tests were utilized for bacterial identification, while the Kirby-Bauer disk diffusion method determined antibiotic susceptibility. Statistical analysis was performed using SPSS version 25. Results: The study population predominantly consisted of residents from Rawalpindi (94.5%). The highest incidence of UTIs was observed in the age group of 31-36 years (34.5%). Staphylococcus aureus (28%) and Pseudomonas aeruginosa (30%) were the most prevalent pathogens. High resistance rates were noted against ampicillin and azithromycin among gram-positive isolates, whereas gram-negative bacteria showed considerable resistance to ciprofloxacin. However, gentamicin displayed relative effectiveness across various pathogens. Conclusion: The study highlights a significant prevalence of antibiotic-resistant UTIs among pregnant women in the studied regions, with Staphylococcus aureus and Pseudomonas aeruginosa being the dominant pathogens. The findings call for an urgent need to implement effective antibiotic stewardship and screening programs during pregnancy to mitigate the risk of UTIs and their associated complications.

Performance evaluation of a Test&Treat rapid detection kit for the diagnosis of septic effusions in dogs and cats.

To evaluate the sensitivity and specificity of a veterinary point-of-care (POC) luminometer-based kit for the diagnosis of septic peritoneal or pleural effusion in dogs and cats. Prospective study performed between January 2020 and July 2021. University teaching hospital. Forty-eight animals with naturally occurring peritoneal or pleural effusion collected by aseptic abdominocentesis or thoracocentesis. Effusion samples were split into filtered (using a 10-micron filter) and unfiltered aliquots and analyzed by the POC instrument according to the manufacturer's instructions and following variable incubation periods. Samples were also plated aerobically on standard and blood agar plates. Proprietary reagents were added to samples, causing bacterial ATP to generate bioluminescence that is detected by the luminometer. Bioluminescence values (relative light units [RLUs]) were recorded and compared with the presence of bacterial growth on the culture plates. Nucleated cell counts in native and filtered effusion samples were recorded. Twenty-one samples were septic based on positive culture. RLUs were higher in septic effusions for filtered and native effusions compared with sterile effusions. The use of a filter reduced cell counts. In filtered samples incubated for 30minutes before testing, the sensitivity and specificity of the luminometer for diagnosis of infection in cavitary effusions were 81% and 82%, respectively, using a cutoff of 12,202 RLUs. The luminometer kit evaluated in this study represents a viable screening tool for diagnosis of septic cavitary effusions and could be used in conjunction with other POC diagnostics to support the rapid diagnosis of infection.

Molecular Characterization of the glyA Gene From the Clinical Isolates of Tannerella forsythia.

TheglyA gene in Tannerella forsythia is attributed for its virulence by producing the enzyme serine hydroxymethyltransferase (SHMT), which plays a vital role in bacterial cell metabolism. The study is thus aimed to determine the frequency of the glyA gene from the clinical strains of T. forsythia isolated from periodontitis patients. Forty-five patients with varying degrees of periodontitis were included in the study, and the plaque samples collected from them were anaerobically processed by inoculating onto sterile anaerobic blood agar plates using a gaspak system, with incubation at 37°C for 5-7 days. The DNA was extracted from the obtained isolated colony, and PCR was performed to confirm the presence of the glyA gene. In total, 46.6% (n= 7) of the cases in group III aggressive periodontitis (n = 15) and 6.66% (n =1) in group II stage II periodontitis (n = 15) showed the presence of T. forsythia,and among them, 57.14% (n= 4) showed the presence of theglyA gene. Conclusion: The findings of the study showed that theglyA gene may be associated with the pathogenesis of T. forsythia and could be thus a novel candidate for the future theragnostic approach to combat periodontitis.

Antibacterial Efficacy of Mineral Trioxide Aggregate, Bioactive Glass and Epoxy-Resin Based Sealer: An In-Vitro Interventional Study.

The aim and objective of this in vitro study was to evaluate the antibacterial efficacy of mineral trioxide aggregate, bioactive glass sealer, and epoxy-resin-based sealer. In the present study, 22 Mueller Hinton agar (MH agar) plates were employed and equally divided into two groups. Three holes were made by removal of agar at equidistant points and filled with root canal sealers. The strains of the bacteria used in this study were S. aureus (ATCC 6538) and C. albicans (ATCC 10231) and were divided into two groups and root canal sealers were divided into three subgroups: mineral trioxide aggregate (MTA) fillapex Sealer, Nishika Bioactive Glass sealer, and Syntex Epoxy Resin base sealer. For Staphylococcus aureus, peptone water was placed in a 2 mL test tube and bacteria were extracted from blood agar plates using a nichrome wire loop and poured into the peptone water-containing test tube and incubated for 2 hours and for C. albicans, fungi were grown at 37°C for 24 hours in MH Broth and seeded into MH agar to produce turbidity of 0.5 on the McFarland scale, which corresponds to a concentration of 108 CFU/mL. This MH broth was used as a second layer. The seeded agar was then added over the plates immediately after the insertion of sealer cement. After incubation, the diameters of zones of inhibition around the plates were measured. The results of this study showed that the highest inhibition was recorded in Syntex sealer against Staphylococcus aureus followed by MTA fillapex sealer and Nishika sealer, whereas MTA fillapex showed the highest inhibition against C. albicans followed by Syntex sealer and Nishika sealer. Syntex sealer exhibits better antibacterial efficacy against Staphylococcus aureus and MTA fillapex exhibit better antibacterial efficacy against C. albicans.

Preventing Bacterial Contamination of Breast Implants Using Infection Mitigation Techniques: An In Vitro Study.

Bacterial contamination of implants has been linked to biofilm formation and subsequent infection, capsular contracture, and breast implant-associated anaplastic large cell lymphoma. Reducing contamination during implant insertion should therefore reduce biofilm formation disease sequelae. The aim of this study was to compare levels of contamination between preventative techniques. A model to simulate the passage of implants through a skin incision was designed that utilized a sterile textured polyvinyl plastic sheet contaminated with Staphylococcus epidermidis. In the first stage of the polyvinyl contamination model, implants were subject to infection-mitigation techniques and passed through the incision, then placed onto horse blood agar plates and incubated for 24 hours. In the second stage of the study the same contamination was applied to human abdominal wall specimens. A 5 cm incision was made through skin and fat, then implants were passed through and levels of contamination were measured as described. Smooth implants grew a mean of 95 colony-forming units (CFUs; approximately 1 CFU/cm2) and textured implants grew 86 CFUs (also approximately 1 CFU/cm2). CFU counts were analyzed by the Mann-Whitney U-test which showed no significant difference between implant types (P < .05); independent-sample t-tests showed a significant difference. The dependent-variable techniques were then compared as groups by one-way analysis of variance, which also showed a significant reduction compared with the control group (P < .01). This in vitro study has shown the effectiveness of antiseptic rinse and skin/implant barrier techniques for reducing bacterial contamination of breast implants at the time of insertion.

Identification of Airborne Aerobic Bacteria in the Intensive Care Room using MALDI-TOF MS

Introduction: Indoor air quality can affect the spread of airborne microorganisms which can lead to healthcare-associated infections (HAIs). The quality and quantity of airborne microorganisms are responsible for mortality and morbidity in infection-prone hosts such as patients admitted to the intensive care unit (ICU). The research aims to determine the quality of microorganisms in the air, identify the types of aerobic bacteria, and assess the physical parameters of the air in the ICU. Methods: This study was a cross-sectional study with a descriptive observational method. Air specimens were collected using the MAS-100 NT tool with blood agar plate solid culture media, which then incubated in an aerobic atmosphere for 24 hours at 37±2°C. Observation and measurement of air microbiological quality was by counting the number of microorganisms in CFU/m3 and identification of bacteria using MALDI-TOF MS. Results and Discussion: The maximum concentration of microorganisms in the air exceeds the standard value, and the average value of the concentration of microorganisms in the air is 736 CFU/m3. The most common types of aerobic bacteria in the air were Bacillus sp. (n=12), Coagulase-negative Staphylococci (n=5), and Staphylococcus aureus (n=5). There was an increase in physical parameters in the form of average temperature (26.24°C) and humidity (70%) with a ventilation system and air regulation using mechanical ventilation sourced from a split air conditioner with an exhaust fan without a high-efficiency particulate-absorbing (HEPA) filter. Conclusion: Low indoor air quality has the potential to increase the concentration of microorganisms and bacterial findings in the air

Comparison of Sinus Flora Using Various Next-Generation Sequencing Techniques Versus Standard Culturing

Background:Next generation sequencing methods are being developed to help diagnose infectious diseases at the point of care and to help resolve discrepant results. These new methods hope to replace longer, more tedious sequencing methods such as Sanger/shotgun sequencing and less sensitive culture results to provide a clinical diagnosis and start appropriate treatment sooner. In lieu of dated techniques, with next generation sequencing the physician could analyze samples in their clinic with relative ease and receive a sensitive diagnosis in a fraction of the time.&#x0D; Objective:To compare percent agreement between standard culturing results of swabbed sinus samples on blood and chocolate agar to BIOFIRE® FILMARRAY® results, and use Oxford Nanopore and 16s illumina sequencing results to resolve discrepancies.&#x0D; Study design:Swabs were taken of the nasal sinuses of 21 patients and flash frozen. Some of these swabs (15/21) were sequenced with 16s illumina sequencing. All these swabs were put into a saline solution and plated on blood and chocolate agar plates as a 1:100 loop dipped into the solution and as the original swab. These solutions were sequenced through the BIOFIRE® FILMARRAY® Torch System on a pneumonia and blood culture (BCID2) panel and through the Oxford Nanopore® MinION Mk1C® system.&#x0D; Results:The pneumonia panel had 36% agreement with blood agar and 52% agreement with chocolate agar plates. Using the top 3 genus results, either Nanopore or 16s illumina sequencing resolved 92% of discrepancies between the pneumonia panel and blood agar and 90% of discrepancies between the pneumonia panel and chocolate agar plates. The blood culture panel had 43% agreement with blood agar and 57% agreement with chocolate agar plates. Nanopore or 16s illumina sequencing resolved 92% of discrepancies between the blood panel and blood agar and 89% of discrepancies between the blood panel and chocolate agar.

Understanding the significance of microbiota recovered from health care surfaces

Microbial contamination of hospital surfaces remains despite adherence to routine disinfection. Our study demonstrates bioburden from various types of hospital high-touch surfaces and the pathogenicity of all bacteria recovered. Several high-touch hospital surfaces from a single medical-surgical unit were sampled and cultured using replicate organism detection and counting (RODAC) Tryptic Soy agar plates. Colonies were then subcultured to blood agar plates and speciated using MALDI-TOF. The local microbiology laboratory database was queried for any clinical isolate match with the environmental samples recovered. Manikins, bed rails, and workstations-on-wheels were the most contaminated surfaces with the largest variety of bacteria isolated from manikins and bed rails. A total of 60 different types of pathogens were isolated, 18 of which were well-known pathogens, and 7 were classified as important in the health care setting by CDC. Our clinical microbiology laboratory identified 29 of 60 hospital surface bacteria in clinical isolates. Urine, soft tissue, and blood were the most common sources of clinical isolates. Surfaces in the health care environment harbor both well-known and not-so-well-known human pathogens. Several not-so-well-known pathogens are skin flora or environmental bacteria, which in the right setting, can become pathogenic and cause diseases including meningitis, brain abscess, endocarditis, and bacteremia.

Evaluation of the antibacterial effect of titanium dioxide nanoparticles combined with acrylic laminates for functional orthodontic appliances: a randomized controlled clinical trial

BackgroundThe objective of this study was to evaluate the antibacterial effect of titanium dioxide nanoparticles incorporated into the acrylic baseplates of the maxillary part of twin block appliances in orthodontic patients during the treatment period.Materials and methodsTwenty-six patients were selected randomly and divided into two groups(n = 13). Test group patients used orthodontic functional appliances containing 1% titanium dioxide nanoparticles in acrylic baseplates. Control group patients used orthodontic functional appliances without titanium dioxide nanoparticles in acrylic baseplates. Swap samples were taken from the palatal gingiva facing the fitting surface of the acrylic component of the maxillary part of a twin block appliance for each patient at five-time intervals (baseline sample, after one, two, four, and six months) and then cultured in blood agar plates to calculate bacterial colony count. The Mann‒Whitney U test and the Friedman test were used to compare data. Bonferroni correction (p value ≤ 0.05) was applied to detect significant differences.The resultsshowed a decrease in the bacterial colony count in the test group compared to the control group. Pairwise comparisons revealed a statistically significant difference in samples after four- and six-month groups (p values = 0.002 and 0.011, respectively) vs. the one-month test group. A higher statistically significant difference was observed in the six-month group (p-value = 0.037) vs. the baseline group in the control group.ConclusionThe addition of 1% titanium dioxide nanoparticles to acrylic baseplates of orthodontic functional appliances significantly reduced the bacterial colony count under the base plate after at least four months of application.

Comparative Evaluation of Antimicrobial Activity of 0.2% Lemongrass Oil and 0.2% Chlorhexidine as a Preprocedural Mouth Rinse: A Randomised Controlled, Parallel Design, Split-mouth Clinical Trial

Introduction: The aerosols produced by an ultrasonic scaler contain bacteria that may enter the respiratory systems of both dental surgeons and patients. Lemongrass oil is one of the essential oils with enormous antibacterial, antifungal, antioxidant, anti-inflammatory, and antipyretic effects. Aim: To evaluate and compare the efficacy of commercially available preprocedural mouth rinses, containing 0.2% lemongrass oil mouthwash and a 0.2% chlorhexidine gluconate solution, in reducing the levels of viable bacteria in aerosols. Materials and Methods: This single-centre double-blinded randomised controlled parallel design split-mouth clinical trial was planned among patients in the Department of Periodontics attending Vishnu Dental College and Hospital in Bhimavaram, Andhra Pradesh, India. The study was conducted for 40 days, from August 2022 to October 2022. Two distinct types of preprocedural mouth rinses (lemongrass oil and chlorhexidine) were used on 56 participants with Stage II or III and Grade B periodontitis. A total of 56 subjects were randomly assigned to two groups: Group A (0.2% lemongrass oil) and Group B (0.2% chlorhexidine), using a simple coin toss method. Colonyforming units (CFUs) with and without rinsing in each group were assessed and studied. CFUs collected on blood agar plates were counted during ultrasonic scaling both with and without rinsing. International Business Machine (IBM) Statistical Package for Social Sciences (SPSS) version 20.0 was used for data analysis. Paired t-tests and independent t-tests were used for intragroup and intergroup comparisons for both groups. Results: The mean CFU count in the chlorhexidine group without rinsing was 259.6±26.6, and with rinsing, it was 140.7±22.6, which was statistically significant (p-value &lt; 0.001). In the lemongrass oil group, the CFU count without rinsing was 263.5±26.9, and with rinsing, it was 147.18±33.82, which was also statistically significant (p-value&lt;0.001). In the intergroup comparison, the p-values for both groups-using preprocedural rinse (Group A vs. Group B for quadrants 2 and 3) and without preprocedural rinse (Group A vs. Group B for quadrants 1 and 4)-were 0.40 and 0.58, respectively, which were not significant. Conclusion: Both preprocedural mouth rinses were equally effective in reducing microbial counts in aerosols during ultrasonic scaling.

Antimicrobial Efficacy of Calcium Hydroxide with Different Herbal Additives: An In-vitro Study

Introduction: Microorganisms such as Enterococcus faecalis, Enterobacteriaceae, and Candida albicans are associated with persisting infections and can cause endodontic failure. The addition of herbal additives such as Triphala, Clove, and Activated charcoal to Calcium hydroxide enhances the microbial efficacy within the root canal. Aim: To evaluate and compare the anti-microbial efficacy of calcium hydroxide with various herbal additives against E. faecalis and C. albicans using Agar Diffusion Test (ADT) and Direct Contact Test (DCT). Materials and Methods: The present in-vitro study was conducted in Bangalore, Karnataka, between July 2023 and September 2023. Ethical clearance was obtained from the institution. Sabouraud Dextrose Agar (SDA) and Mueller-Hinton Agar were prepared and used to culture C. albicans and E. faecalis, respectively. In each plate, four wells were filled with groups (n=10): Group-I: Nanocalcium hydroxide (NCH)+sterile distilled water, Group-II: NCH+Nanoparticle Clove, GroupIII: NCH+Nanoparticle Triphala, Group-IV: NCH+nanoparticle activated charcoal. The plates were incubated at 37°C, and zones of inhibition around the wells were measured on the first, third, and seventh day. DCT was evaluated in Colony Forming Units (CFUs)/ml by adding each bacterial suspension to four groups and inoculating on blood agar plates. One-way ANOVA test followed by Tukey’s post-hoc analysis was used to compare the mean Zone Of Inhibition (ZOI). Kruskal-Wallis Test followed by Mann-Whitney post-hoc test was used to compare the mean CFUs. Results: One-way ANOVA test showed that there was a significant difference in the mean ZOI between the four groups at p=0.005. The maximum mean ZOI against C. albicans was achieved by the combination of calcium hydroxide and clove with an average mean of 22.20±1.92 mm, 20±1.87 mm, and 17.20±2.28 mm on the 1st, 3rd, and 7th day, respectively. Calcium hydroxide with distilled water combination showed the highest mean ZOI against E. faecalis with an average mean of 18.20±0.84 mm on day 1, 17±1 mm on the 3rd and 7th day. The mean CFUs of E. faecalis and C. albicans showed a significant difference between the four groups at p&lt;0.001. Conclusion: The addition of herbals to Calcium hydroxide increased anti-microbial activity against Candida albicans and Enterococcus faecalis.

Isolation of Lignocellulolytic Bacteria From Erek-erek Geoforest Ijen Geopark, Indonesia

Ijen Geopark is one of the UNESCO Global Geoparks in Indonesia. The Erek-erek Geoforest (EEG) is one of the biosites in the Ijen Geopark. The EEG has an abundant biomass which is composed of lignocellulosic complex. The abundance of biomass has the potential as a source of lignocellulolytic microorganisms that can degrade lignocellulose material. The purpose of this research was to isolate lignocellulolytic bacteria from the Erek-erek Geoforest. This research method was soil sampling, physicochemical analysis of soil, isolation, and purification of bacteria, growth capability in lignocellulose media, and pathogenicity-test. The results showed that a total of 180 were isolated from EEG. There are 93 bacteria growth in lignin media and 142 bacteria growth in cellulolytic with the isolated code EIB (erek-erek Ijen Banyuwangi) under aerobic conditions which had various bacterial morphologies. To ensure the safety of using these isolates, it is necessary to do a pathogenicity test of these bacteria using a blood agar plate. Indicated pathogenic bacteria will form a clear zone around the bacterial colony on the blood media. The pathogenicity test of the highest lignocellulolytic bacteria showed that the 3 ligninolytic and 3 cellulolytic EIB bacteria isolates were non-pathogenic. Further, non-pathogenic bacteria from the soil litter of erek-erek forests can be tested for their potential as biological agents for the industry.

Prevalence of Extended‐Spectrum Beta‐Lactamase Producer Gram‐Negative Rods and Associated Factors Among Patients With Wound Infection at University of Gondar Comprehensive Specialized Hospital, Northwest Ethiopia

Background: Multidrug‐resistant (MDR) bacteria have significantly affected the management and treatment of wound infections globally. Data on the prevalence of MDR bacterial profiles that cause wound infections in Ethiopia are scarce. Therefore, this study aimed to determine MDR as well as extended‐spectrum beta‐lactamase production profiles of Gram‐negative rods that are difficult to treat with conventional antibiotics and that cause wound infections.Objective: The aim of the study was to determine the prevalence of extended‐spectrum beta‐lactamase producer Gram‐negative rods and associated factors among patients with wound infection at University of Gondar Comprehensive Specialized Hospital, northwest Ethiopia.Materials and Methods: This hospital‐based cross‐sectional study was conducted at University of Gondar Comprehensive Specialized Hospital between May and July 2022. Convenience sampling was used to recruit 228 participants. Swabs from different wound types were inoculated onto the MacConkey agar and blood agar plates and incubated overnight at 37°C for 24 h. Biochemical tests were performed on isolated colonies for the identification of bacterial species based on their biochemical reaction. Antimicrobial susceptibility tests were performed using the disk diffusion technique as per the standard Kirby–Bauer method by using Muller–Hinton agar, and the zone of inhibition was interpreted as resistant, intermediate, and sensitive as per the recommendation of Clinical Laboratory Standard Institute. Isolates were tested against ceftriaxone, cefotaxime, and ceftazidime for extended‐spectrum beta‐lactamase screening using the Kirby–Bauer disk diffusion method, and combined disk tests were applied for phenotypic confirmatory test of extended‐spectrum beta‐lactamase producing isolates.Result: Of 228 study participants, 162 (71.1%) were culture‐positive. Among culture‐positive patients, 165 Gram‐negative bacteria were recovered. The most common Gram‐negative isolates were Pseudomonas aeruginosa (47; 28.5%), followed by Escherichia coli (43; 26.1%) and Klebsiella pneumoniae (24; 14.5%). The susceptibility rates of the isolate for imipenem and tobramycin were 97.0% and 73.2%, respectively, and the overall multidrug resistance rate was 80.5%. Extended‐spectrum beta‐lactamase producer bacteria were also isolated. Besides, all (100%) of extended‐spectrum beta‐lactamase producer bacteria were MDR. Living in rural areas (AOR 5.8; 95% CI [2.01–16.7]), hospital admission (AOR 3.95; 95% CI [1.13–13.83]), antibiotic use (AOR 2.83; 95% CI [1.03–7.72]), and comorbidity (AOR 0.25; 95% CI [0.07–0.59]) were significantly associated with wound infection.Conclusions and Recommendations: There was a high prevalence of Gram‐negative bacterial isolates in this study. Pseudomonas aeruginosa (28.5%) was the predominant isolate. In addition, high rates of multidrug resistance were observed. The high level of multidrug resistance in this study implies that definitive therapy should be based on culture and susceptibility analysis to promote the rational use of antibiotics and to reduce the emergence of bacterial resistance to antimicrobials.